**Mining Safety and Sustainability II**

Editors

**Longjun Dong Yanlin Zhao Wenxue Chen**

MDPI • Basel • Beijing • Wuhan • Barcelona • Belgrade • Manchester • Tokyo • Cluj • Tianjin

*Editors* Longjun Dong Central South University China

Yanlin Zhao Hunan University of Science and Technology China

Wenxue Chen University of Sherbrooke Canada

*Editorial Office* MDPI St. Alban-Anlage 66 4052 Basel, Switzerland

This is a reprint of articles from the Topic published online in the open access journals *Energies* (ISSN 1996-1073), *Minerals* (ISSN 2075-163X), *Safety* (ISSN 2313-576X), *Sensors* (ISSN 1424-8220), and *Sustainability* (ISSN 2071-1050) (available at: https://www.mdpi.com/topics/Mining Safety).

For citation purposes, cite each article independently as indicated on the article page online and as indicated below:

LastName, A.A.; LastName, B.B.; LastName, C.C. Article Title. *Journal Name* **Year**, *Volume Number*, Page Range.

**ISBN 978-3-0365-6398-5 (Hbk) ISBN 978-3-0365-6399-2 (PDF)**

© 2023 by the authors. Articles in this book are Open Access and distributed under the Creative Commons Attribution (CC BY) license, which allows users to download, copy and build upon published articles, as long as the author and publisher are properly credited, which ensures maximum dissemination and a wider impact of our publications.

The book as a whole is distributed by MDPI under the terms and conditions of the Creative Commons license CC BY-NC-ND.


**Abstract**

As quantum computers with sufficient computational power are becoming mature, the security of classical communication and cryptography may compromise, which is based on the mathematical complexity. Quantum communication technology is a promising solution to secure communication based on quantum mechanics. To meet the secure communication requirements of multiple users, multipointinterconnected quantum communication networks are specified, including quantum key distribution networks and quantum teleportation networks. The enabling technologies for quantum communication are the important bases for multipointinterconnected quantum communication networks. To achieve the better connection, resource utilization, and resilience of multipoint-interconnected quantum communication networks, the efficient network architecture and optimization methods are summarized, and open issues in quantum communication networks are discussed.

**Keywords:** multipoint-interconnected, quantum communication networks, quantum key distribution, quantum teleportation

#### **1. Introduction**

Quantum communication such as Quantum Key Distribution (QKD) and Quantum Teleportation (QT) is capable of exploiting the principles of quantum mechanics to transport classical, or even quantum, bits of information. quantum communication networks extend the concept of quantum communications, since they can transport, elaborate, and store quantum information (qubits) between different node pairs. Quantum communication networks leverage the principles of quantum mechanics including no-cloning, quantum measurement, entanglement, and teleporting. Hence, the new networking and computing capabilities emerge. At the same time, new and challenging constraints are imposed on the design and operations of quantum communication networks. This chapter firstly introduces the quantum communication enabling technologies including QKD and QT; then focuses on the research about QKD networks and QT networks to enable multipoint interconnection such as the architecture and service provisioning algorithms; finally, pays attention to problems and challenges of QT networking.

## **2. Quantum communication enabling technologies**

The realizations of quantum communication network mainly include quantum key distribution technology and quantum teleportation technology.

#### **2.1 Quantum key distribution**

Quantum cryptography, which applies quantum properties to design the secure communication system, is the subset of quantum communication. QKD technology is a realization of quantum cryptography. It generates and distributes symmetrical cryptographic keys with information theoretical security based on the fundamental laws of quantum physics, i.e., the security is independent of all future advances of algorithm or computational power. QKD has the characteristic of "point-to-point" implementation. Thanks to the developments of quantum relay and switching technologies, the long-distance QKD is enabled. The following two subsections briefly introduce the QKD implementation and the related quantum relay and switching technologies to realize long-distance quantum communication.

#### *2.1.1 Quantum key distribution implementation*

The first quantum key distribution (QKD) protocol, the famous BB84 protocol, was proposed by Charles Bennett and Gilles Brassard in 1984 [1]. Since then, a series of QKD protocols such as E91, B92, SARG04, COW, DPS, GG02, MDI-QKD have been proposed one after another. There are three main implementation technologies of QKD: Discrete-Variable Quantum Key Distribution (DV-QKD), Continuous-Variable Quantum Key Distribution (CV-QKD), and Measurement Device-Independent Quantum Key Distribution (MDI-QKD). DV-QKD encodes information on a single photon and uses a single-photon detector for detection. DV-QKD originated earlier and is more mature, with a longer safe transmission distance. Besides, multi-node quantum network has been successfully established. The disadvantage is that single-photon sources are tricky to prepare [2]. Unlike DV or qubit-based QKD, the secret keys in CV-QKD are encoded in quadrature of the quantized electromagnetic field and decoded by coherent detections, which is lower cost and more practical. Under the same conditions, the output key rate of CV-QKD is much higher than that of the DV-QKD, and it is highly integrated with traditional optical communication networks. However, the current CV-QKD technology is not as good as the DV-QKD technology in terms of safe transmission distance, and the problem of working bandwidth also needs to be further resolved [3]. The security of MDI-QKD does not depend on whether the quantum device is trusted or not. MDI-QKD completely removes all security loopholes in the detection system and ensures a QKD network security with untrusted relays. Compared with CV-QKD, MDI-QKD can obtain higher security key rate, but the communication distance is shorter, and the channel is required to be asymmetric (that is, the measurement equipment is required to be close to the user on one side) [4].

In the past 10 years, a series of small-scale QKD technology verification networks have been built abroad, covering local area networks, metropolitan area networks, and intercity networks [5–9]. At the same time, a number of major technical research studies have been carried out in China to address quantum secure communication. Local area networks, metropolitan area networks, intercity networks, and wide area networks have carried out related work, including the quantum communication Beijing-Shanghai trunk line project for connecting metropolitan area networks, and the planned satellite-ground integrated wide-area quantum communication network. To keep faint quantum signals apart from intensive classical data signals, traditional QKD networks utilize low-noise dedicated fibers, such as dark fibers, which will significantly increase QKD deployment cost. Also, researchers have studied how to combine QKD deployment onto existing optical networks [10].


*Edited by Elmer P. Dadios*

Advances in automation and control today cover many areas of technology where human input is minimized. This book discusses numerous types and applications of automation and control. Chapters address topics such as building information modeling (BIM)–based automated code compliance checking (ACCC), control algorithms useful for military operations and video games, rescue competitions using unmanned aerial-ground robots, and stochastic control systems.

ISBN 978-1-83969-173-7

Automation and Control - Theories and Applications

Published in London, UK © 2022 IntechOpen © Thinkhubstudio / iStock

## Automation and Control Theories and Applications

*Edited by Elmer P. Dadios*


**6.2 Innovative planning research, moving from projects to policy and programs**

Spatial planning research has received little attention compared to development and economic planning with the two misconstrued as synonyms. Research is taken as inquest to learn what, why and how on issues of urban development. Thus even a simple field visit trip by a building inspector on a site can be monitoring but when data is collected for use later it has many research implications. Spatial planning focused research is required on substantive issues to influence outputs and outcomes of planned interventions. This has in a way directed spatial planning in terms of 'projects' and one can argue that there has been a 'projectization' of planning itself and urban development in general. The consequence is a scattering of often slightly improved neighborhoods, industrial parks and developments due to piloting while many remain in poor conditions. The key urban challenges on which planning research is useful and needed include urban livelihoods, urban environment, urban poverty, urban transportation about which knowledge is scattered, inadequate or requiring to identify alternative models for provision of services and guiding urban development. In addition there are various dynamic conditions in the urban field including governance, resource mobilization and management, the increasing role and creativity of the private-sector which despite being vibrant are also less understood from the planning point of view.

Planning practice is influenced by many factors including education and training. This section will give experiences of the practice and potentialities of scaling up the innovations.

There are possibly many ways through which planning innovation can be achieved and in this section of the chapter, an attempt is taken to describe some of the key areas in which

Spatial planning research has received little attention compared to development and economic planning with the two misconstrued as synonyms. Research is taken as inquest to learn what, why and how on issues of urban development. Thus even a simple field visit trip by a building inspector on a site can be monitoring but when data is collected for use later it has many research implications. Spatial planning focused research is required on substantive issues to influence outputs and outcomes of planned interventions. This has in a way directed spatial planning in terms of 'projects' and one can argue that there has been a 'projectization' of planning itself and urban development in general. The consequence is a scattering of often slightly improved neighborhoods, industrial parks and developments due to piloting while many remain in poor conditions. The key urban challenges on which planning research is useful and needed include urban livelihoods, urban environment, urban poverty, urban transportation about which knowledge is scattered, inadequate or requiring to identify alternative models for provision of services and guiding urban development. In addition there are various dynamic conditions in the urban field including governance, resource mobilization and management, the increasing role and creativity of the private-sector which despite being vibrant are also less understood from the planning

**6.2 Innovative planning research, moving from projects to policy and programs**

or city consultation approaches offer innovations space.

**6.1 How can planning innovate?**

point of view.

**6. Practice and promise of innovative urban planning**

The section is based on real cases of the studies conducted in the region.

innovations are required and how such innovation can be harnessed.

enabling efficient public transport and thresholds to support concentrations of economic activity, services and facilities. On the other hand, 'new urbanism' adheres to similar spatial principles, but at the scale of the local neighborhood. This position promotes a vision of cities with fine-grained mixed use, mixed housing types, compact form, an attractive public realm, pedestrian-friendly streetscapes and defined centers. However, it should be pointed out that there is considerable overlap between these categories; some emphasize process and others outcomes and sometimes a combination (UN-Habitat, 2009). In the Eastern African context, efforts at attempting innovative participatory planning approaches have largely been spearheaded by international agencies, for example, the joint initiative of UNEP/UN-Habitat Sustainable Cities Programme in Dares-Salaam, Tanzania and the Local Agenda 21 initiative in Nakuru, Kenya. In general, the urban Environmental Planning and Management (EPM) approaches, technologies and know-how through urban local authorities based on broad-based stakeholder participatory Following the adage that "knowing a problem cause means you have solutions for it", its imperative for planning to reflect on these challenges probably with adapted or different lenses. From basic to applied research and now participatory research, these domains offer great opportunities to support planning innovation, knowledge generation and making informed planning interventions. Some of these research undertakings have been very revealing. For example whereas the planning has always grappled with the issue of 'standards' in respect to land and housing, the revelation is that possibly many people are not in position to afford such 'high standards' and coupled with other factors this influences the urban development imprint in the region(Rakodi and Lloyd-Jones, 2002, Rakodi, 1997, Rakodi, 2001). Research indicates that with this experience and projectization, a move from projects to policy thinking is necessary(McGill, 1988, Arimah and Adeagbo, 2000, Lotz-Sisitka). A move that entails programming of urban development but which recognizes incrementalism or phasing but most important ensuring sticking to plans through the routine actions that would lead to the desired goals. Participatory research has provided some insights but maybe not answers (Lwasa and Kadilo, 2010). A triple helix model that would enable a platform of knowledge generation and exchange would be useful, one which brings together, local governments, governments on one hand, research organizations/NGO's as second category and communities as the third category, to investigate problems and search for local-based solutions within affordable ranges (Egbu et al., 2006, Higgs, 2008, Williams et al., 1999). The bringing together of various actors in urban development is now widely recognized and some of the initiatives include Urban Fora for discussion, prioritizing and directing knowledge generation for search of solutions.

A key input for planning is information on the substantive issues as well as processes (Mahavir, 2005, Lwasa, 2005) which is related to knowledge. Planning usually is preceded with collection of large data volumes, which sometimes are never processed to useful information nor getting utilized. Given the gamut of planning information needs, it means that any initiative to collect, analyze and utilize planning information could have experienced a situation of 'too much' data and 'less' utilized. This is not a surprise because planning usually projects development into the future, which may be uncertain. From social and economic surveys to spatial information on land use and other physical components, data are collected but partly analyzed. Arguably, there is an assumption that with the scale of data collection, the solutions to urban problems would be understood, explained and solutions derived. Not all the data collected by planners is actually used in a plan-making exercise. In fact "very little," a planner will discretely reply as observed by (Mahavir, 2005) that only 60% of data actually become input for plan making. The reason that planners collect so much data is a conventional approach influenced by the planning models described earlier in the chapter. Huge amounts of time and other resources are spent on collecting and analysing the same data, which in turn delays the start of the planning process, sometimes by several years Mahavir further observes. Differentiation, between essential and desirable data should provide the answer to the resources an aspect not given due attention. The key issue here is that both in terms of financial resources and time, this information takes an enormous share but if an evaluation is conducted, one wonders whether such scale of data analysis has really translated into solutions in East Africa. The innovation around planning information is likely to come from strategic determination and use of planning information given the level at which our information systems are. This would mean skimming through the available information as well as urban problems to

Reappraising Urban Planning and Urban Sustainability in East Africa 15

society. A possible innovation would be to use an ecological planning approach which localizes problems and solutions as well building on the existing resources available. One of the key principles of such planning is transparency in order to respond to social needs. It is

Planning in sub Saharan Africa still remains largely technocratic, a field of practice for highly-trained and sophiscated professionals with less inclusive rules, regulations and standards(Koojo, 2005). Such planning expects adherence or non-adherence from the communities with the later followed by the 'stick' using the regulations. While it is important to have rules, regulations and standards, there is also need to recognize that such should be responsive to social needs which differ from neighborhood to another and between societies. Societal needs reflect both existential and ideals but what planning policy in East Africa responds to is largely the societal ideals. One needs to reflect on the 'societal values' theory in planning which among other tenets underpins the ideals of 'space'. In the context of urban space, one would have to muddle through differing conceptions of space depending on how it is defined and who defines it. The other issue is who determines how it would be used. Connected to the space paradox is power which is defined in governance structures(Leibowitz et al.). Existing and contemporary planning such as the rationalistic planning are silent about the roles of communities in regard to the ideals, space definition and decision making. Yet broadly speaking planning is about dialogue to enable decision making and from African perspective planning in current times is arguably about responding to needs of majority urban dwellers who have remained in deplorable conditions. In this vein, the planning has not adequately promoted decision making that is embracing communities. Often, solutions are handed down to them and this has for a long time shaped the community thinking as that of being on the receiving end. Redefining the community roles from largely receivers to major decision making stakeholders(Andersson et al., 2004) is a key innovation. This is one of the most talked about approach to 'new planning' but which has not been fully tested due to limitations regarding resources. But not testing participation has also not yielded positive results for better communities. It is important once again to note that deconstructing a neighborhood would possibly require enormous resources than constructing it with the

As the search for inclusive urban space utilization solutions progress, innovative urban design is responding to the realities of societal needs through innovative research and knowledge generation. A mix of innovators whose desires to see a transformation of the East African cities is leading to emergence of a community of practice. For example because residential land use puts the greatest demand on urban land compared to any other use, its importance is no doubt placing it high on the planning innovation agenda. Based on a case in Kampala which was preceded by urban management policy innovation, urban design can now consider integration of urban agriculture with housing making the best use of limited space but providing housing, incomes and food while maintaining the environmental services. Making the Edible Landscape project by Kampala City Council was showcased at WUF III Vancouver and during the last session of WUF IV, Kampala was again showcased

probably what (Bennett, 2003) calls sociocratic planning.

**6.4 Redefining community roles**

communities progressively and incrementally.

**6.5 Innovative urban design**

identify essential data for the planning exercise. Those which if utilized would have a multiplier effect in solving other related problems. This implies dealing with the 'most important problem' that Amdam and Veggeland (1998) called the 'garbage-can-model' in which the decision making process are activated through identifying the problems, active participants and a stream of solutions by those experiencing such problems.

In practical terms, assuming urban problems of livelihoods for majority of dwellers and public transportation are serious issues in a city. If collection of data about each would have to run baselines, it would be a huge undertaking. By strategic determination and skimming, the stakeholders may view livelihoods as the most important problem and would be interested in innovatively creating employment that may translate in improved incomes, possibly having multiplier effects on housing and vibrant urban economy. This is applicable to existing cities and neighborhoods and from our research, livelihoods based strategies have a place in innovative planning(Lwasa and Kadilo, 2010). In comparison, the public transport multiplier effect may be largely in regard to the energy sector and incomes (KCC and Bank, 2000). It should be noted that the resources required for the example of studying livelihoods are likely to be far much lower than those for improving public transport. One must note however that coupling urban system components such as the two raised here would possibly produce better results and possibly in a much quicker way. However the multiplier effects should not deter investment in large infrastructure like transportation. Basing on a Kampala experience, it emerged that over 60% of the urban dwellers use either walk or cycle modes of transportation to and from their places of work. Yet resources that go into improving roads and traffic counts have been enormous. In this case innovative planning that tackles either livelihoods coupled with alternative modes of transport or one that addresses only alternative modes of transport would most likely respond to the existential needs compared to traffic counts and improvement of road infrastructure.

#### **6.3 Mobilizing resources for planning; From costs of plan production to societal costs**

Mobilizing resources has been touched on mainly as a big challenge in urban management(McGill, 1988). Mobilizing financial resources remains a long standing huddle in planning and urban development. Attention has been put on costs for producing plans as the case for the Master and Structure Plans. One important point is that most city or municipal scale plans have been produced with largely external funding. This is likely to continue unless there emerges an alternative strategy for mobilization of resources. There is also the much talked about local and or community level mobilization of resources which has either fallen a victim of projectization or simply not upscaled despite the good lessons(Andersson et al., 2004). There is little evidence of existing systems and initiatives for utilizing locally available resources for planning and its interventions. Yet the costs of not planning are actually those of not doing it and the planning profession cannot afford to continue this way. The societal costs are huge and if one attempted to translate them in monetary terms, it is alarming. For example in one of the study within Kampala, health related impacts of environmental burdens were monetized for the direct and indirect costs and results show that 15% of a household income is spent on defensive expenditure or costof-illness expenditure. For that neighborhood alone, a total economic value of \$ 1.7 m (Lwasa et al., 2008)was calculated and if one factors in the neighborhoods with similar conditions, the cost is by no doubt high. The costs have become increasingly huge for our society. A possible innovation would be to use an ecological planning approach which localizes problems and solutions as well building on the existing resources available. One of the key principles of such planning is transparency in order to respond to social needs. It is probably what (Bennett, 2003) calls sociocratic planning.

#### **6.4 Redefining community roles**

14 Urban Development

identify essential data for the planning exercise. Those which if utilized would have a multiplier effect in solving other related problems. This implies dealing with the 'most important problem' that Amdam and Veggeland (1998) called the 'garbage-can-model' in which the decision making process are activated through identifying the problems, active

In practical terms, assuming urban problems of livelihoods for majority of dwellers and public transportation are serious issues in a city. If collection of data about each would have to run baselines, it would be a huge undertaking. By strategic determination and skimming, the stakeholders may view livelihoods as the most important problem and would be interested in innovatively creating employment that may translate in improved incomes, possibly having multiplier effects on housing and vibrant urban economy. This is applicable to existing cities and neighborhoods and from our research, livelihoods based strategies have a place in innovative planning(Lwasa and Kadilo, 2010). In comparison, the public transport multiplier effect may be largely in regard to the energy sector and incomes (KCC and Bank, 2000). It should be noted that the resources required for the example of studying livelihoods are likely to be far much lower than those for improving public transport. One must note however that coupling urban system components such as the two raised here would possibly produce better results and possibly in a much quicker way. However the multiplier effects should not deter investment in large infrastructure like transportation. Basing on a Kampala experience, it emerged that over 60% of the urban dwellers use either walk or cycle modes of transportation to and from their places of work. Yet resources that go into improving roads and traffic counts have been enormous. In this case innovative planning that tackles either livelihoods coupled with alternative modes of transport or one that addresses only alternative modes of transport would most likely respond to the existential needs compared to traffic counts and

**6.3 Mobilizing resources for planning; From costs of plan production to societal costs**  Mobilizing resources has been touched on mainly as a big challenge in urban management(McGill, 1988). Mobilizing financial resources remains a long standing huddle in planning and urban development. Attention has been put on costs for producing plans as the case for the Master and Structure Plans. One important point is that most city or municipal scale plans have been produced with largely external funding. This is likely to continue unless there emerges an alternative strategy for mobilization of resources. There is also the much talked about local and or community level mobilization of resources which has either fallen a victim of projectization or simply not upscaled despite the good lessons(Andersson et al., 2004). There is little evidence of existing systems and initiatives for utilizing locally available resources for planning and its interventions. Yet the costs of not planning are actually those of not doing it and the planning profession cannot afford to continue this way. The societal costs are huge and if one attempted to translate them in monetary terms, it is alarming. For example in one of the study within Kampala, health related impacts of environmental burdens were monetized for the direct and indirect costs and results show that 15% of a household income is spent on defensive expenditure or costof-illness expenditure. For that neighborhood alone, a total economic value of \$ 1.7 m (Lwasa et al., 2008)was calculated and if one factors in the neighborhoods with similar conditions, the cost is by no doubt high. The costs have become increasingly huge for our

participants and a stream of solutions by those experiencing such problems.

improvement of road infrastructure.

Planning in sub Saharan Africa still remains largely technocratic, a field of practice for highly-trained and sophiscated professionals with less inclusive rules, regulations and standards(Koojo, 2005). Such planning expects adherence or non-adherence from the communities with the later followed by the 'stick' using the regulations. While it is important to have rules, regulations and standards, there is also need to recognize that such should be responsive to social needs which differ from neighborhood to another and between societies. Societal needs reflect both existential and ideals but what planning policy in East Africa responds to is largely the societal ideals. One needs to reflect on the 'societal values' theory in planning which among other tenets underpins the ideals of 'space'. In the context of urban space, one would have to muddle through differing conceptions of space depending on how it is defined and who defines it. The other issue is who determines how it would be used. Connected to the space paradox is power which is defined in governance structures(Leibowitz et al.). Existing and contemporary planning such as the rationalistic planning are silent about the roles of communities in regard to the ideals, space definition and decision making. Yet broadly speaking planning is about dialogue to enable decision making and from African perspective planning in current times is arguably about responding to needs of majority urban dwellers who have remained in deplorable conditions. In this vein, the planning has not adequately promoted decision making that is embracing communities. Often, solutions are handed down to them and this has for a long time shaped the community thinking as that of being on the receiving end. Redefining the community roles from largely receivers to major decision making stakeholders(Andersson et al., 2004) is a key innovation. This is one of the most talked about approach to 'new planning' but which has not been fully tested due to limitations regarding resources. But not testing participation has also not yielded positive results for better communities. It is important once again to note that deconstructing a neighborhood would possibly require enormous resources than constructing it with the communities progressively and incrementally.

#### **6.5 Innovative urban design**

As the search for inclusive urban space utilization solutions progress, innovative urban design is responding to the realities of societal needs through innovative research and knowledge generation. A mix of innovators whose desires to see a transformation of the East African cities is leading to emergence of a community of practice. For example because residential land use puts the greatest demand on urban land compared to any other use, its importance is no doubt placing it high on the planning innovation agenda. Based on a case in Kampala which was preceded by urban management policy innovation, urban design can now consider integration of urban agriculture with housing making the best use of limited space but providing housing, incomes and food while maintaining the environmental services. Making the Edible Landscape project by Kampala City Council was showcased at WUF III Vancouver and during the last session of WUF IV, Kampala was again showcased

Reappraising Urban Planning and Urban Sustainability in East Africa 17

Acts, the models and principles. If unpacked, the toolbox is changing but not at a speed desirable to fit in with the strategic determination of planning information to focus on essential data as well as linking policy guides to policy-action. Contemporary planning tools are dynamic and changing very fast(Mahavir, 2005, Lwasa, 2005). In Uganda for example, the toolbox has changed but there are still many areas for improvement around which innovations can be generated. In this section the planning toolbox elements of Acts, data and equipment are the focus. Starting off with the Acts, in East Africa have not been inclusive and sensitive to the needs of Africans. In addition the code of conduct professional and ethics have not been strengthened for long until recently. For example in Uganda the revision of the Town and Country Planning Act 1964 into the new Physical Planning Bill is very laudable and provides a platform for innovation(2008). One of the many innovations in the new bill is the response to the longstanding planning question of 'planning area boundary', by including rural areas and implicitly the peri-urban, the bill provide mandate to planning authorities to prepare or cause prepare plans for areas with a potential to explode outside the official planning area boundary as local physical development plans. In Kenya the creation of the Nairobi Metropolitan Ministry in 2008 is a laudable effort in establishing formal structure to address the metropolitan growth of the city. Planning education needs to quickly embrace these new changes from the public policy domain and prepare future planners to respond within such laws. While the other two components of accurate data and equipment are some of the areas with urgent need for innovation. While working in partnership with other professions and disciplines, it is important to address the need for spatial information, techniques for plan formulation and design of planning information systems that would probably reduce the costs of planning information collection and analysis as discussed earlier. The emergence of Global Navigation Satellite Systems (GNSS), Global Positioning Systems (GPS), Geographic Information Systems (GIS), Remote Sensing with associated systems of Spatial Data Infrastructure (SDI), web-based mapping, online planning are areas worth exposing to future planners (Lwasa, 2005). These techniques and tools provide means for quick accurate information which can aid quick response to planning problems while helping in establishing planning information systems. They also provide a powerful advantage of enabling community-access to planning information, designs and neighborhood conditions that reduces the burden on the part of

For a long time there has been an argument that planners in Africa have a theoreticalprofessional-practice foundation with a global north touch(James Otieno, 2009). This is true given the history of planning education in sub-Saharan Africa that was characterized by first level training in a different discipline before receiving training in planning at graduate level. Evidence shows that the switch to African based training and education in planning has provided the much needed human resource to confront the urban development challenge with argument that local training will enable planners to gunner experiential knowledge in terms of planning needs, problems and solutions(Diaw et al., 2002). But what is yet to be seen is the translation of this experiential training into real solutions to the local planning problems and challenges(DPU, 2004, Breidlid, 2009). One of the many attributes of this type of training is that it still largely remained shaped by planners whose skills, theory, practice and models do not properly align with the urban development pathways in East Africa.

planning authorities.

**6.8 Planning education**

as one of the innovative cities by responding to the societal experiential needs (food, incomes, nutrition) through designs. Although both the results and outcomes of this innovative design are yet to be fully realized, it is a very promising innovation worth replicating and up scaling. It has further advantages of providing a basis for urban adaptive designs to climate change and variability. As contributors to GHG's and the cities vulnerability to climate change effects, adaptive urban designs that focus on plot-level hydrological, climatic and vegetative systems can have profound impact through cumulative progression of localized changes.

#### **6.6 Informality, formality and institutional reform**

From commentaries, research and evaluations, the informalization of urban development in East Africa has been well documented(UN-Habitat, 2008). Informality is however occurring amidst formal rules of engagement in urban development(Jain, 2003). Planning has not been spared by this informalization. There has been a good discussion of the fusion of the two seemingly different systems(Lwasa, 2006). Whereas informality has largely imitated the formal rules with adaptation, formal systems are also characterized by informality. In Kampala and Nairobi for example, the dualistic nature of urban development ((Koojo, 2005, Lwasa, 2006, Nkurunziza, 2008) describes informality of housing, infrastructure installations, services but also the development control procedure which is an important planning-policy action. The key issue regarding formality and informality concerns rules of engagement defined by institutional setup. These specify how individuals relate in urban development, their roles and responsibilities. Experience shows that institutions are characterized by three blanket levels for enforcement of the rules. The first is the *official policy rules* which are often well documented. The second is the *unofficial policy rules* that are not documented but are part of the routine policy-action of individuals in positions of public institutions. While the third are what can be considered as the *official-unofficial policy rules* that are neither documented but the guides of routine planning-policy action. To substantiate these rules, the discussion will focus on the last two. The unofficial policy rules are the type which individuals practice based on patronage, favors and sometimes selfish acts. Because of the risks associated with boldly identifying oneself as an agent of unofficial policy rules, this is always hidden and due to this the third category is created. The third official-unofficial policy rules are a very powerful type which lie beneath the official policy rules. They are exercised by a network of individuals in or out of organizations and often known by all staff from the top to bottom connecting to the clientele through selective information dissemination and informal channels. The rules are often described as 'usual' based on connivance, sharing information from identifying 'clients' execution of 'missions'. This has created different layers of procedures and stages in planning but also planning policy-action. Planning has not properly addressed these dynamic political and social processes of dispensation of services. The innovation in this sphere is by no doubt 'noble' and will have to involve adapting the official policy rules. The role of leadership is very significant in enabling innovation in this sphere and critical in this much desired change.

#### **6.7 The planning toolbox**

For long, the planning toolbox has also remained a black box in the sense that it has been so technocratic. The planning toolbox has components such as accurate data, equipment, the

as one of the innovative cities by responding to the societal experiential needs (food, incomes, nutrition) through designs. Although both the results and outcomes of this innovative design are yet to be fully realized, it is a very promising innovation worth replicating and up scaling. It has further advantages of providing a basis for urban adaptive designs to climate change and variability. As contributors to GHG's and the cities vulnerability to climate change effects, adaptive urban designs that focus on plot-level hydrological, climatic and vegetative systems can have profound impact through

From commentaries, research and evaluations, the informalization of urban development in East Africa has been well documented(UN-Habitat, 2008). Informality is however occurring amidst formal rules of engagement in urban development(Jain, 2003). Planning has not been spared by this informalization. There has been a good discussion of the fusion of the two seemingly different systems(Lwasa, 2006). Whereas informality has largely imitated the formal rules with adaptation, formal systems are also characterized by informality. In Kampala and Nairobi for example, the dualistic nature of urban development ((Koojo, 2005, Lwasa, 2006, Nkurunziza, 2008) describes informality of housing, infrastructure installations, services but also the development control procedure which is an important planning-policy action. The key issue regarding formality and informality concerns rules of engagement defined by institutional setup. These specify how individuals relate in urban development, their roles and responsibilities. Experience shows that institutions are characterized by three blanket levels for enforcement of the rules. The first is the *official policy rules* which are often well documented. The second is the *unofficial policy rules* that are not documented but are part of the routine policy-action of individuals in positions of public institutions. While the third are what can be considered as the *official-unofficial policy rules* that are neither documented but the guides of routine planning-policy action. To substantiate these rules, the discussion will focus on the last two. The unofficial policy rules are the type which individuals practice based on patronage, favors and sometimes selfish acts. Because of the risks associated with boldly identifying oneself as an agent of unofficial policy rules, this is always hidden and due to this the third category is created. The third official-unofficial policy rules are a very powerful type which lie beneath the official policy rules. They are exercised by a network of individuals in or out of organizations and often known by all staff from the top to bottom connecting to the clientele through selective information dissemination and informal channels. The rules are often described as 'usual' based on connivance, sharing information from identifying 'clients' execution of 'missions'. This has created different layers of procedures and stages in planning but also planning policy-action. Planning has not properly addressed these dynamic political and social processes of dispensation of services. The innovation in this sphere is by no doubt 'noble' and will have to involve adapting the official policy rules. The role of leadership is very significant in enabling innovation in this sphere and critical in this much desired change.

For long, the planning toolbox has also remained a black box in the sense that it has been so technocratic. The planning toolbox has components such as accurate data, equipment, the

cumulative progression of localized changes.

**6.7 The planning toolbox**

**6.6 Informality, formality and institutional reform**

Acts, the models and principles. If unpacked, the toolbox is changing but not at a speed desirable to fit in with the strategic determination of planning information to focus on essential data as well as linking policy guides to policy-action. Contemporary planning tools are dynamic and changing very fast(Mahavir, 2005, Lwasa, 2005). In Uganda for example, the toolbox has changed but there are still many areas for improvement around which innovations can be generated. In this section the planning toolbox elements of Acts, data and equipment are the focus. Starting off with the Acts, in East Africa have not been inclusive and sensitive to the needs of Africans. In addition the code of conduct professional and ethics have not been strengthened for long until recently. For example in Uganda the revision of the Town and Country Planning Act 1964 into the new Physical Planning Bill is very laudable and provides a platform for innovation(2008). One of the many innovations in the new bill is the response to the longstanding planning question of 'planning area boundary', by including rural areas and implicitly the peri-urban, the bill provide mandate to planning authorities to prepare or cause prepare plans for areas with a potential to explode outside the official planning area boundary as local physical development plans. In Kenya the creation of the Nairobi Metropolitan Ministry in 2008 is a laudable effort in establishing formal structure to address the metropolitan growth of the city. Planning education needs to quickly embrace these new changes from the public policy domain and prepare future planners to respond within such laws. While the other two components of accurate data and equipment are some of the areas with urgent need for innovation. While working in partnership with other professions and disciplines, it is important to address the need for spatial information, techniques for plan formulation and design of planning information systems that would probably reduce the costs of planning information collection and analysis as discussed earlier. The emergence of Global Navigation Satellite Systems (GNSS), Global Positioning Systems (GPS), Geographic Information Systems (GIS), Remote Sensing with associated systems of Spatial Data Infrastructure (SDI), web-based mapping, online planning are areas worth exposing to future planners (Lwasa, 2005). These techniques and tools provide means for quick accurate information which can aid quick response to planning problems while helping in establishing planning information systems. They also provide a powerful advantage of enabling community-access to planning information, designs and neighborhood conditions that reduces the burden on the part of planning authorities.

#### **6.8 Planning education**

For a long time there has been an argument that planners in Africa have a theoreticalprofessional-practice foundation with a global north touch(James Otieno, 2009). This is true given the history of planning education in sub-Saharan Africa that was characterized by first level training in a different discipline before receiving training in planning at graduate level. Evidence shows that the switch to African based training and education in planning has provided the much needed human resource to confront the urban development challenge with argument that local training will enable planners to gunner experiential knowledge in terms of planning needs, problems and solutions(Diaw et al., 2002). But what is yet to be seen is the translation of this experiential training into real solutions to the local planning problems and challenges(DPU, 2004, Breidlid, 2009). One of the many attributes of this type of training is that it still largely remained shaped by planners whose skills, theory, practice and models do not properly align with the urban development pathways in East Africa.

Reappraising Urban Planning and Urban Sustainability in East Africa 19

background of urbanisation in Africa, which is inextricably linked to European colonisation with the net result of there being many experiences of the interactions between global North oriented type planning and urban development experiences in sub-Saharan Africa (Lwasa, 2008; Akatch, 1995; Kessides, 2006). In addition, various urban planning instruments in sub-Saharan Africa were critically examined. From the onset, it was emphasized that the master plan approach remains the most dominant to date, although in recent years this particular instrument has been increasingly criticized for being complex, excessively bureaucratic, time consuming, non participatory and too static in nature. The potential offered by new urban approaches was briefly discussed including the key elements underpinning them although it was emphasized that these approaches did not suggest models or solutions, which could be

In conclusion, spatial planning in East Africa is at cross-roads and facing a huge challenge as the demographic shift creates an urbanized. Planning innovation is necessary to change the current urban development trends and imprint but such innovation will have to involve various stakeholders and in various spheres. The key spheres that could have multiplier effects include; planning practice, planning research, planning information and redefining community roles. For better communities in urban areas the response of the planning profession should address the social needs and endeavor to harness the potentials of communities based on the realities of current development. This is the key for transforming urban communities in East Africa. The time for planning innovation in East Africa is past and in this context the planning profession as well as other stakeholders should take initiative and start now because the cost of not adequately planning is so huge. However, several weaknesses of the participatory processes have been identified that create limits of

Akatch, S. 1995. "Evaluative Review of Urban Planning Practice and Experiences in Africa"

Andersson, N., Matthis, J., Paredes, S. & Ngxowa, N. 2004. Social audit of provincial health

Arimah, B. C., Jensen, I., Mutizwa-Mangiza, N. D. & Yemeru, E. A. 2009. Planning

Arimah, C. B. & Adeagbo, D. 2000. Compliance with urban development and planning

Arko-Adjei, A., Jong, J. D., Zevenbergen, J. & Tuladhar, A. Customary Tenure Institutions

Bennett, R. G. 2003. Planning Theory and Power. Center for Studies of Environment and

regulations in Ibadan, Nigeria. *Habitat International* 24, 279-294.

in Mosha, A (ed). 1995. A Reappraisal of the Urban Planning Process. Nairobi: UN-

services: Building the community voice into planning in South Africa. *Journal of*

Sustainable Cities: Global Report on Human Settlements 2009. New York: UN-

and Good Governance. *In:* FIG, ed. International Federation of Surveyors, 2010.

literally transplanted from one context to another.

**9. References**

Habitat.

Habitat.

FIG, 17.

2008. The Physical Planning Bill, 2008. *31.*

*Interprofessional Care,* 18, 381-390.

Resources, University of Bergen.

new approaches to urban planning in the Eastern African region.

Thus innovation around education is necessary and such would have experiential knowledge but also solutions that are responsive to the problems of African urbanism. For example the issue of planning standards for housing (materials, sizes, plot coverage) has been discussed at different fora and international level but has not been substantively resolved nor have flexible or adaptive standards developed (Rakodi, 1997). However good practices or cases from various countries including Uganda, Tanzania have considered mixed residential with light industry to take into consideration of home-based small scale industrious activities. This is just one among the many ways in which planning education can be innovative. This innovation required in broad requires an in-depth review and reorganization of the education system.


**7. Local anesthetics**

The most commonly used LA are 0.5% bupivacaine and tetracaine, at doses of 0.3–0.6 mg/kg. Although ropivacaine and levobupivacaine are also safe and effective agents. Ropivacaine 0.5% at doses of 0.5–1 mg/kg, produce a good quality block. With ropivacaine, the motor block is significantly shorter and less intense than with bupivacaine. Levobupivacaine 0.5% at a dose of 0.3–1 mg/kg, is also used clinically with a less intense motor block, similar to ropivacaine.

Bupivacaine, ropivacaine, and levobupivacaine are drugs that are broken down by enzymes in the liver. Therefore, they should be used carefully in PNB because they have a lower capacity to metabolize both anesthetics due to their immaturity [17]. Term NB metabolize LA well, but not preterm infants or patients with other comorbidities.

The duration of action of all spinal LA is one of the great limitations of using this route, since its duration is relatively short, it does not exceed 80 minutes in most of them. Postoperative analgesia is very short. For this reason, many clinicians have used so-called LA adjuvants such as adrenaline, morphine, or fentanyl, to prolong its duration. Most of them manage to extend the duration of action for a time no longer than 30%. However, their safety is questionable due to the possible toxicity of the adjuvants to the development of the spinal cord, which can be vulnerable. Intrathecal medications can allow the development of toxicity by altering the neuronal activity of the spinal cord [18–20].

#### **8. Complications of spinal block**

The complications of SA in children are similar to those in adults. However, the evaluation of signs and symptoms is difficult to identify, especially in NB or younger than one year compared to older children. Physiological and behavioral changes rather than verbal ones manifest their conditions.

The main complications of SA may result from the technique used or from the action of the LA itself. In general, the incidence of side effects is low and permanent secondary sequelae have not been reported in most clinical studies. They are shown in **Table 2** [14].

Complications include headache and low back pain, neurological complications, nausea, vomiting, and cardiorespiratory changes. Elevated levels of spinal block, above T4, reduce the expansion movement of the lower rib cage, decreasing intercostal muscle activity and paradoxical respiratory movements may occur.

**Table 2.**

*Complications of spinal block in children [14].*

Monitoring of oxygen saturation and an oxygen source are necessary. Post-puncture headache is the most frequent complication, it has an incidence of 3 to 4%, even with the use of spinal needles 25–27, and the incidence increases with spinal needles number 22. The headache appears in the first 24 hours post-puncture and may be unilateral or bilateral. It worsens with changes in position from lying to sitting and some children may manifest nausea and vomiting, which may be accompanied by blurred vision, vertigo, and tinnitus. These symptoms usually disappear spontaneously in three to five days, and in some children, they can continue for several more days. Caffeine is the pain reliever of choice in children [21].

#### **9. Spinal anesthesia and short-stay surgery**

Another reason to prefer SA in the child is the low cost compared to GA, in addition to the rapid recovery from short-stay surgery and early return home. These advantages include a rapid recovery derived from the short duration of SA with rapid recovery of mobility of the lower extremities, and prompt restoration of the oral route, with a low incidence of postoperative nausea and vomiting [22].

#### **10. Sedation**

Sedation is often used in the child, for the application of the spinal puncture. The goal of sedation is to produce anxiolysis and to ensure that the child remains motionless during the lumbar puncture. Movement during puncture can cause significant trauma to neurovascular structures. Midazolam, ketamine, propofol, dexmedetomidine, or inhaled sevoflurane can be used. However, any of them can be associated with periods of apnea. The safest are inhaled agents like sevoflurane. Dexmedetomidine produces a natural sleep state and produces anxiolysis and analgesia. Sedatives should be avoided in preterm, weak or high-risk newborns [15].

#### **11. Discussion**

SA has been used for a variety of surgical procedures, including inguinal hernia, exploratory laparotomy, omphalocele, and gastroschisis repair, multiple orthopedic procedures mainly of the lower extremities, pylorotomy, and surgery of the anus, bladder, and penis. Epidemiological data show that newborns have a higher risk of complications associated with GA. In multiple studies, the technique that has shown

#### *Spinal Anesthesia in Pediatrics DOI: http://dx.doi.org/10.5772/intechopen.100590*

efficacy and safety and that has avoided the use of general anesthesia in the group of preterm, ex-preterm, or high-risk patients has been SA. Most clinicians prefer SA because it is associated with great respiratory and cardiovascular stability, allowing greater survival for newborns. In large study populations on the usefulness of SA, it has been shown that oxygen desaturation of <90% is rarely observed, and < 5% of newborns require supplemental oxygen, although neonates are notoriously susceptible to present hypoxia in response to external stimuli such as surgical stress.

The incidence of apnea in the NB in the first 12 hours postoperatively associated with GA, ranges between 10% and 30%. This seems to be directly related to prematurity and general anesthetics, 70% of apnea is of central origin, 10% obstructive and 20% combined. To the multiple advantages of SA in children, we can add postoperative analgesia with a short hospital stay, a lower cost for the hospital, and a lower incidence of mechanical ventilation after surgery [14, 15, 17, 23].


**2. Preliminaries**

In this section, we recall some definitions and properties of interval-valued fuzzy sets (*IVF*) and interval-valued fuzzy soft sets (*IVFS*). Note that, throughout this paper, *X* and *E* denote the sets of objects and parameters, respectively. I*X* and [I] *X*, where I = [0, 1] and [I] = {[*a*, *b*], *a* ≤ *b*, *a*, *b* ∈ I} denote, respectively, the set of all fuzzy subsets and the set of all interval-valued fuzzy subsets of *X*.

**Definition 1.** *Ref. [2] A pair* (*f* , *X*)*, is called an IVF subset of X if f is a mapping given by f* : *X* → [I] *such that for any x* ∈ *X*, *f*(*x*)=[ *f* −(*x*), *f* +(*x*)] *is a closed subinterval of* [0, 1] *where f* −(*x*) *and f* +(*x*) *are referred to as the lower and upper degrees of membership x to f and* 0 ≤ *f* −(*x*) ≤ *f* +(*x*) ≤ 1*.*

In 1999, Molodtsov [5] defined the concept of soft sets (SS) for the first time as a pair of (*f* , *E*) or *fE* such that *E* is a parameter set and *f* is the mapping *f* : *E* → 2*X* where for any *e* ∈ *E*, *f*(*e*) is a subset of *X*. By combining the concepts of soft sets and interval-valued fuzzy sets, a new hybrid tool was defined as the following.

**Definition 2.** *Ref. [25] A pair* (*f* , *E*) *is called an IVFS set over X if the mapping f is given by f* : *E* → [I] *X where for any e* ∈ *E and x* ∈ *X, f*(*e*)(*x*)=[ *f* −(*e*)(*x*), *f* +(*e*)(*x*)]*.*

Consider two *IVFSs fE*, *gE* over the common universe *X*. The union of *fE* and *gE*, denoted by *fE*∨˜ *gE*, is the *IVFSs* (*f* ∨˜ *g*)*E*, where ∀*e* ∈ *E* and any *x* ∈ *X*, we have (*f* ∨˜ *g*)(*e*)(*x*)=[max{ *f* − *e* (*x*), *g*− *e* (*x*)}, max{ *f* + *e* (*x*), *g*+ *e* (*x*)}]. The intersection of *fE* and *gE*, denoted by *fE*∧˜ *gE*, is the *IVFSs* (*f* ∧˜ *g*)*E*, where ∀*e* ∈ *E* and ∀*x* ∈ *X*, we have (*f* ∧˜ *g*)(*e*)(*x*)=[min{ *f* − *e* (*x*), *g*− *e* (*x*)}, min{ *f* + *e* (*x*), *g*+ *e* (*x*)}]. The complement of *fE* is denoted by *f c E* and is defined by *f c* : *E* → [I] *X* where ∀*e* ∈ *E* and any *x* ∈ *X*, *f c*(*e*)(*x*) = [1 − *f* + *e* (*x*), 1 − *f* − *e* (*x*)]. The null *IVFSs*, denoted by ∅*E*, is defined as an *IVFSs* over *X* such that *f* − *e* (*x*) = *f* + *e* (*x*) = 0 for all *e* ∈ *E* and any *x* ∈ *X*. The absolute *IVFSs*, denoted by *XE*, is defined as an *IVFSs* over *X* where *f* − *e* (*x*) = *f* + *e* (*x*) = 1, ∀*e* ∈ *E* and any *x* ∈ *X*.

Using the matrix form of interval-valued fuzzy relations, authors in [39] represented a finite IVFSs *fE* as the following *n* × *m* matrix

$$f\_{\mathbb{E}} = \left[ [f\_{ij}^-, f\_{ij}^+] \right]\_{n \times m} = \begin{bmatrix} [f\_{\varepsilon\_1}^-(\mathbf{x}\_1), f\_{\varepsilon\_1}^+(\mathbf{x}\_1)] & \dots & [f\_{\varepsilon\_1}^-(\mathbf{x}\_m), f\_{\varepsilon\_1}^+(\mathbf{x}\_m)] \\ \vdots & \dots & \vdots \\ [f\_{\varepsilon\_n}^-(\mathbf{x}\_1), f\_{\varepsilon\_1}^+(\mathbf{x}\_1)] & \dots & [f\_{\varepsilon\_n}^-(\mathbf{x}\_m), f\_{\varepsilon\_1}^+(\mathbf{x}\_m)] \end{bmatrix}\_{n \times m}$$

where | *E* |= *n*, | *X* |= *m* and *f* −*ij*= *f* − *ei*(*xj*), *f* +*ij* = *f* + *ei*(*xj*) for *i* = 1, . . . , *n* and *j* = 1, . . . , *m*.

Accordingly, the concepts of union, intersection, complement, etc., can be represented in a matrix format in the finite case.


2.5.1 Direct costs

Direct costs refer to the amounts of money spent directly on treating or managing a given illness or more specifically, the amounts of money spent at medical institutions for the treatment and management of such illness. These costs can be further broken down into direct healthcare costs and direct non-healthcare costs. The direct healthcare costs include the costs of outpatient and/or hospitalization services and purchasing medications (including prescribed medications) to treat the given illness. Furthermore, it includes the costs incurred by outpatients and

Methodology of Estimating Socioeconomic Burden of Disease Using National Health Insurance… DOI: http://dx.doi.org/10.5772/intechopen.89895

#### Table 3.

Costs estimated based on different perspectives.

hospitalized patients alike due to disease, encompassing covered costs paid by insurer, copayments paid by patients, non-covered costs, and prescription costs.

The direct non-healthcare costs refer to the expenses paid by patients to visit and use the services of medical institutions, such as the costs of transportation and caregiving.

## 2.5.2 Indirect costs

Indirect costs refer to the losses of labor and productivity that are incurred in addition to the tangible (financial) costs of an illness. Examples include the amounts of time taken off (paid) work to go to medical institutions and the loss of future expected income, not only of patients but also of their family members or other loved ones who are compelled to care for them. The latter example may also be expressed as the opportunity costs of being ill, including the losses of working hours and leisure time.

The indirect costs, or losses of productivity, are estimated by defining the number of hospitalization days as the number of working days lost and the amounts of time spent for outpatient visits, as losses of working time. The losses of future income are due to the premature deaths of patients.

### 2.5.3 Intangible costs

The intangible costs represent the decline in the quality of life and psychological suffering of patients and loved ones. However, it is notoriously difficult to define and quantify these costs with precision (Drummond et al., 2005). Due to the scarcity of related data and the difficulty of quantification, researchers often forgo estimating these costs (Table 4).

#### Table 4.

Cost components and definitions.


**Abstract**

Maize (Bhutta) is one of the important growing cereal crops in Bangladesh. Toxigenic fungi such as *Aspergillus* and *Fusarium* infect stored maize grains. Enzyme-linked immusorbent assay (ELISA) was used to determine total aflatoxins and fumonisins contamination in stored maize grains collected from 15 Bangladeshi maize-producing areas. The highest total concentration of aflatoxins (103.07 µg/kg) and fumonisin (9.18 mg/kg) was found in Chuadanga and Gaibandha, whereas the lowest was detected for aflatoxins (1.07 µg/kg) and (0.11 mg/kg) in Dinajpur and Cumilla, respectively. The findings clearly demonstrated that aflatoxin concentrations in samples from six regions and fumonisin concentrations in samples from 10 regions were beyond the regulatory limit of aflatoxin (10 ppb) and fumonisin (1 ppm), respectively, as set by European Union (EU). However, a positive correlation between aflatoxins with toxigenic *A. flavus*, and fumonisins with toxigenic *Fusarium* spp. was observed. The fungi associated with maize grains were identified by sequencing of ITS regions. Moreover, toxigenic *A. flavus* was confirmed using primers specific to *nor*, *apa2*, *omtA* and primer FUM1 for *F. proliferatum* and *F. oxysporum*. Since the Bangladesh Food Safety Authority has not authorized any precise regulation limits for maize mycotoxin contamination, these results will serve as a benchmark for monitoring mycotoxin contamination in maize and also to develop globally practiced biocontrol approach for producing safe food and feed.

**Keywords:** mycotoxins, maize, threat, food, security


*2.3. Transfections, Selection, and Cell Cloning*

Electrotransfection of circular DNA was performed using a Bio-Rad Gene Pulser apparatus and electroporation conditions as described [39]. Briefly, promastigotes grown to mid-log phase were harvested by centrifugation (1251 *g*, 10 min, 4 ◦C), washed twice with ice-cold phosphate-buffered saline (PBS), once in pre-chilled electroporation buffer, and suspended in electroporation buffer at a density of 1 × 108 parasites/mL.

For the generation of double allele replacements and for the integration of linearised DNA constructs, cells were transfected following the Amaxa protocol as described previously [17,40]. Briefly, 1 × 107 promastigotes grown to mid- to late-log phase were harvested by centrifugation at 1251 *g* for 10 min (at RT), washed once with 1 × Tb-BSF electroporation buffer (90 mM NaHPO3, 5 mM KCl, 0.15 mM CaCl2, 50 mM HEPES, pH 7.3) [41] at RT, and suspended in 150 µL electroporation buffer per transfection. For gene editing, the cell suspension was mixed with the pooled unpurified PCR amplicons for the two single-guide RNA (sgRNA) templates and two donor DNAs (combined volume approximately 100 µL, heat-sterilised at 94 ◦C for 5 min before transfection) in a total volume of 250 µL. For integration of transgenes into the 18S SSU rRNA locus, cells were mixed with 2 µg of the *Swa*I-linearised DNA construct. Electroporation was performed in a 0.2 cm gap Gene Pulser electroporation cuvette (Bio-Rad, München, Germany) using one pulse with program X-001 in the Amaxa Nucleofector IIb device (Lonza, Basel, Switzerland). A mock transfection control without DNA was included to check the real transfection efficiency.

Following electroporation, cells were immediately transferred into 5 mL drug-free pre-warmed complete M199 medium in 25 cm2 cell culture flasks. After parasite recovery at 25 ◦C for 16–20 h, the selection antibiotics were added at the indicated strain-specific concentrations. Nourseothricine (ClonNat, at 150 µg/mL for all parasite species; Werner BioAgents, Jena, Germany), hygromycin B (at 50 µg/mL for all parasite species; Roth, Karlsruhe, Germany), bleocin (at 5 µg/mL; Calbiochem, San Diego, CA, USA). Additionally, blasticidin (at 10 µg/mL for *L. donovani* and *L. major*; at 2.5 µg/mL for *L. braziliensis*; Roth, Karlsruhe, Germany) and puromycin (at 25 µg/mL for *L. donovani* and *L. major*; at 10 µg/mL for *L. braziliensis*; Sigma-Aldrich, München, Germany) were used to select for integration of the donor gene fragments. For *L. braziliensis*, double drug-resistant cell populations with the intended gene replacements were first selected at a lower selection pressure as indicated until they emerged in culture (about 2–3 weeks), followed by an increase in the selection pressure (at ~IC99.7:

5 µg/mL blasticidin; ~IC96: 20 µg/mL puromycin) to allow discrimination with the mock-transfected control cultures.

For cloning by limiting dilution, exponential log-phase cultures of the candidate *L. braziliensis HSP23-* and *HSP100*-null mutants were seeded in complete M199 medium at 0.5 cells per well in two 96-well microtitre plates, as described previously [39]. After 14 days, monitoring of wells for promastigote growth by light microscopy was started and continued until growth-positive wells were observed. The contents of positive wells were seeded into 2 ml complete M199 medium maintaining the drug pressure (blasticidin and puromycin at ~IC96–IC99.7) in 25 cm2 cell culture flasks to expand the culture. Each population that emerged from an individual well was considered an individual clone.


Electrolyte Disturbances

**Chapter 9**

**Abstract**

patients.

**137**

**1. Introduction**

Electrolytes in the ICU

*Syed Zaidi, Rahul Bollam and Kainat Saleem*

**Keywords:** Electrolytes, Sodium, Potassium, critically ill, ICU

important ICU scenarios which could affect electrolytes.

**2. Disorders of sodium homeostasis**

Electrolyte disorders is an imbalance of certain ionized salts (sodium, potassium, calcium, bicarbonate, chloride) in the blood. Healthcare providers should be familiar with the principles of electrolyte physiology and pathophysiology. Disturbances in sodium homeostasis are primarily caused by volume abnormalities leading to primarily neurologic symptoms. Dyskalemias frequently present with cardiac manifestations therefore should be treated promptly before evaluating its cause. Ion deficiencies such as hypocalcemia, hypomagnesemia and hypophosphatemia should be corrected as they are associated with increased adverse events in critically ill

Electrolytes are elements that naturally occur in the human body and help balance pH, facilitate passage of fluid through osmosis and regulate the function of neuromuscular, endocrine and excretory systems. Disturbances in these electrolytes are common clinical problems encountered in the intensive care unit with serious complications when they are depleted. Recent studies report that electrolyte imbalances are associated with increased morbidity and mortality. Possible mechanisms include damage to the kidney, activation of hormonal systems (such as RAAS) or the myriad of medication given in a critically ill patient. This chapter will focus on various electrolyte abnormalities seen in the critical care setting then touch on

• Serum sodium reflects the plasma tonicity and is inversely related to total body water. Changes in sodium are generally due to changes in total body water, not serum sodium, which regulates plasma tonicity and effective arterial volume. The body normally prevents plasma sodium to stray outside normal range (135

to 145 mEq/L or mmol/L) by controlling water intake and excretion.

• Sodium crosses systemic capillary membranes through clefts between endothelial cells therefore sodium concentration is identical in plasma and interstitial fluid [1]. Brain capillaries have tight endothelial junctions lined by astrocytic foot processes creating the blood–brain barrier which sodium cannot cross [2]. Consequently, an abnormal plasma sodium causes water movement across the blood brain barrier leading to either brain swelling or shrinkage.


*3.6. Nanostructured Sca*ff*olds*

Scaffolds are artificial constructs that provide support, tensile strength, and aid in tissue ingrowth [555]. They can also serve as carriers for growth factors, drugs and other required ingredients [556]. Scaffolds mimic the presence of extracellular matrix and allow the replacement of tissue without producing any harmful disturbance with respect to surrounding tissues. An ideal scaffold should be biocompatible, biodegradable, bioactive, non-toxic, mechanically stable, biodegradable, and bioresorbable (Figure 27) [557]. The amalgamation of organic and inorganic materials with scaffolds may enhance morphology and mechanical properties, thus supporting better cell attachment and proliferation [558].

**Figure 27.** Desired properties of an ideal scaffold.

Scaffold properties can be improved by using nanoparticles because organic and inorganic minerals in natural bone have nanoscale structures [559]. Many studies found that the addition of titanium and iron improve biological and mechanical properties such as collagen synthesis and apatite generation [560,561]. In addition, engineered nanofibrous scaffolds are also suitable for loadbearing applications and can replace natural extracellular matrix (ECM) with artificial ECM. The nanofibrous scaffold can therefore get a much more suitable environment for cellular growth and eventual regeneration of the bone [562]. Nanofiber-based scaffolds have been fabricated by using different synthetic polymers including PCL [563–566], PLLA [567,568], copolymer [569], PLGA [61], and chitosan [569].

Different kinds of metallic nanoparticles can be used for the synthesis of composite-based scaffolds with enhanced mechanical characteristics, cell adhesion, and bone tissue generating capacity [12]. The incorporation of titanium, iron, and alumoxane in a scaffold can improve mechanical properties, collagen synthesis, calcium deposition, and alkaline phosphatase activity [561].

Graphene and its derivatives were used as reinforcement material for fibrous scaffolds, films, and hydrogels [570]. The graphene and graphene oxide incorporation into hydrogels yield enhancements in mechanical properties without producing adverse effects on encapsulated fibroblast cells [571]. Carbon-based nanomaterials can be used to improve mechanical strength of scaffolds [572]. Alumina, titania, bioglass, and hydroxyapatite support osteoblast adhesion and growth [573].

Nanobiomaterial-based composite structures are an efficient platform for the synthesis of engineered scaffolds and application in bone tissue engineering (Figure 28) [574]. Nanocomposite-based scaffolds exhibit inherent characteristics such as porous and rough surface and increased wettability, which promote fast bone regeneration. These nanocomposite-based scaffolds provide a porous structure for nutrients exchange and increased protein adsorption. Scaffolds exhibited micro/nano-scaled porous structural pathway for cell–scaffold interaction and integrin-triggered signaling pathway. The nanoscale features support bone cells (osteoblast) and bone-derived stem cells proliferation, migration, cell signaling, stem cell fate, and genetic cell fate. The nanobiomaterials based scaffold have notable mechanical and biological advantages and can induce bone tissue regeneration [531]. The nanostructured materials improve morphological characteristics of scaffolds that may enhance

osteoinduction, bone cell attachment, differentiation, proliferation, and natural bone cell growth within the extracellular matrix [12].

**Figure 28.** Engineered organic and inorganic nanobiomaterials for hard tissue engineering applications.

Hydroxyapatite (HA) has attracted attention because of its inherent biological compatibility and bone conduction as well as its similarity with bone minerals [575]. For this reason, HA was combined with a number of synthetic and natural polymers such as polycaprolactone [576], poly (lactic acid) (PLA) [577], polyethylene, poly(lactic-co-glycolic acid) (PLGA) [203], collagen [578], gelatin [148], and chitosan [579] to fabricate scaffolds. These composite based scaffolds showed improved mechanical properties, porosity and biocompatibility without or with significantly less adverse effects.


**4. Specific application: hydrocarbon leak sensors. The thermomechanics principles**

oxygen molecules through a reducing reaction which causes the release of electrons and allows that a current flows freely through the sensor. Consequently, the gas concentration is detected by the resistance change of MOS [4]. This kind of sensor seems to be the most important because the huge amount of investigation regarding to them. Pt nanoparticles-modified Al-doped ZnO (AZO) porous macro/mesoporous nanosheets prepared by solution combustion method were assessed for butane gas sensor at low temperature. The large surface area of 50.17 m2

the broad pore size distribution between 3 and 110 nm calculated by BJH method provided a good contacting interface between sensing material and gas molecules allowing a maximum response of 56–3000 ppm of butane. The gas sensitivity is related to the electron flow through the interface from AZO to Pt. An oxidation-reduction reaction happened when Pt nanoparticles-modified AZO nanosheets were exposed to reducing gas. A large amount of electrons are released which back to the conduction band of AZO leading a decrease of resistance [39]. Hierarchical flower-like structure composite formed by combination of metal oxides with high surface area and porous structure have shown improved gas sensing performance in comparison with pure metal oxide. NiO:CuO nanocomposites (molar ratio 1:1) showed 2 s response

formed at the interface between NiO and CuO could accelerate the speed response. O2

these gas molecules are adsorbed onto the surface by extracting electron from conduction band.

uated thought output voltage measurements and the sensing response was defined by the ratio

The existence of p-n junction in composite sensor which induced a new potential barrier when

to 450°C. Sensor response (S) was determined following the equation S = Rair/Rgas, where Rair and Rgas are the sensor resistances recorded in presence of test gas and dry air, respectively. The ini-

ing, leading 85 kΩ at 250°C and 18 kΩ at 450°C in ethanol sensing test. In addition, the sensor response increased from 1.77 to 3.29 with increasing ethanol concentration from 50 to 500 ppm

for ethanol detection [42]. In order to improve its ethanol sensing capability at the temperature range between 25 until 125°C, other researchers have been introduced Au nanoparticles into ZnO nanostructures by sputtering technique. The sensing mechanism is based on the surface electron density changes of the semiconductor. The oxygen molecules in air react to the surface electrons of ZnO forming oxygen species determined by the constant reaction koxy as follows:

O3

 particles gave benefits to exhibit superior gas sensing performance. The reduction of operating temperature was attributed to lower energy required for electron transition derived from the decrease of band gap of p- and n-type semiconductor [41]. In another work, porous hol-

ecules are absorbed on the surface of sensor when it is exposed to air. These O2

with n-type SnO2

ture electrons from conduction band of sensing material forming ions O2

O5

method and were evaluated for sensing ethanol, CO, and NH3

perature (100°C) and high response (800–5 ppm NO2

at room temperature and relative humidity of 42%. The heterojunction

, the resistance is decreased [40].

in composite sensor for NO2

and air atmospheres.  Low sensor response to CO and NH3

The combination of p-type Sb2

electrons transfer between SnO2

of sensor resistance in NO2

tial resistance of α-Fe2

SnO2

/g and

mol-

molecules cap-

have also eval-

O5 and

atmosphere,

− . At NO2

) at short time (5 s) of composite sensor.

in a temperature range from 250

nanoparticles were synthesized by hydrothermal

was detected, thus, this sensor is suggested only

Diverse fluids used in the petrochemicals processes such as propane, liquid petroleum gas (LPG), butane, propylene; and other organics and inorganics fluids are widely stored, transported, or used in a pressure-liquefied state. Therefore, these fluids are very important in the industry when leak sensing technology is needed. Specifically, pressure-liquefied gas (PLG have a high probability of ending in a fatal accidental leak due to its own fluid properties and behavior [48, 49]. So, sensing technology needed must cover a range of fluids; however, there are some clear examples where the widely and frequently used of some fluids highlight some extra needs for specially design sensors or sensing technology.

#### **4.1. Theoretical basis of the problem: phenomenon involved**

Flashing depends on the initial parameter values of the fluid as pressure and temperature as well as the type of fluid. A particular combination of those variables can create, for some cases, a complete breaking of the liquid core into droplets at the same time that it is going out of container like unstable two phase jet or liquid jet. The major difficulty in the understanding of this flashing phenomenon and the parameters interactions within it belongs to the existence of a compromise between the physical and thermodynamics mechanism that acts on the released fluid [50]. Specific behavior and characteristics of these liquid-gas mixtures and the potential for the formation of vapor-liquid aerosols during a superheated liquid release due to the breaking of the metastable state can significantly affect the hazard zone and the mitigation steps that can be taken to minimize the release impact for the hydrocarbon industry [49, 51, 52].

Geometrical characteristics as diameter of the nozzle, length of the nozzle in the experimental system have influence on the dynamics behavior of the system, driving the velocity profile as well as the temperature profile. Evaporation and convection processes are also involved and their relevance along the leaking fluid properties as well as the characteristics of the jet is not well determined yet. Even so, in more recent works, some authors applied the jump condition analysis to the shock waves in the discharge of a superheated liquid [59]. Due to the metastable liquids supply the energy stored within them via the latent heat of vaporization,

Porous Ceramic Sensors: Hydrocarbon Gas Leaks Detection

http://dx.doi.org/10.5772/intechopen.72315

61

the evaporation wave was assumed as an adiabatic phase transition.

**based on the concept**

**4.2. Identification of key parameters for sensing technology: viability for sensing**

As direct consequence of the understanding of the process, it is possible to evaluate the potential of different variables or parameters to detect in the best possible way any leak, keeping in mind that the primary purpose of leak detection systems is to assist pipeline operators in detecting and locating leaks. The first aspect to consider is the magnitudes of the scale of mass discharge, the critical explosion limits, change in temperature of the surrounding, the time scale of the process, or any other parameters that be used to catch this phenomenon. Mass discharge directly seems to be no a convenient parameter to be measured directly but based on the amount of mass going out concentration of the leaked fluid in the surrounding will change. As described, this variable will depend on several physical parameters such as pressure difference, temperature, and fluid properties that will determine the discharge velocity. Time scale of the leak is related with the jet velocity; however, the thermodynamics process of phase change are under the influence of another parameter as the fluid properties, which can be described based on the temperature variation along the centerline of the yet. Initially, there is a time lag of the initiation of flashing, followed by a drop of temperature driven by a phenomenon of sudden change of phase and finally an increment of the temperature to the ambient condition driven mainly by the mechanics mechanism of energy exchange. Characteristics of centerline droplets temperature of a R134a flashing jet by using and exponential function, which started with an almost exponential decay with the fastest drop in the temperature taking place near the nozzle exit, explained by the presence of rapid evaporation of the droplets and the insufficiency of the convective heat transfer from the surrounding [54]. This exponential decay of droplets average temperature can be described by an exponential function followed by less rapid temperature decay. Meanwhile, experimental data have pointed out that for different substances that there is a visible minimum in the temperature profile that can be related with the factor the mechanics mechanisms take over the thermodynamics mechanics of energy exchange [60]. Mentioned time scales are not commonly reported, however, it is possible to be calculated using the equilibrium model [61]. A different approach described that the flashing process can be detected based on the fact that rapid vaporization or phase change of superheated fluid produced an acoustic pulse that can detect by an acoustic sensor [62, 63]. Nucleation of vapor bubble requires a minimum amount of energy related to the vibrating media that will be traduced in pressure waves (noises). As mentioned in Section 3, the ceramics porous materials (e.g., catalytic and MOS sensors) are other available options for sensing hydrocarbon vapors and this will be discuss in details on the next section.

High complexity level of the whole process in combination with the need of more information based on experimental, analytical, or numerical models is the main difficulty to be overcome in order top developed new sensing technology. Different authors have concentrated efforts of the jet characterization. The developed information about the jet can help to understand the parameters that can be used as key indicators of accidental release of hydrocarbons.

Flashing phenomenon complexity required calculation of the velocity discharge, void fraction, and mass flow of a flashing jet together with the estimation of the temperature. Due to the nature of the nucleation process, the assumptions of adiabatic flow with non-reversible work for the surface tension forces are made. Those considerations are found to be more realistic that the isentropic condition used until now by different authors. Dynamics conditions usually considered include the mixture velocity after flashing as critical conditions. Frequently numerical modeling techniques are only applied after the flashing jet is formed. No droplets generation or vapor generation are included in the modeling. Droplets are imposed as part of the boundary condition of a gas jet. Droplets transport mechanics and their interaction and momentum exchange with the gas current is made using droplet interaction models as for example Disperse Model (DDM). Geometrical aspects as nozzle dimension, as well as, turbulent model used have a large impact on the core region length of the velocity profile. The numerical results are compared based on the centerline or cross section velocity profiles [53].

In general, centerline, the temperature profile presents an initial decay from the exit of the nozzle until a certain distance, where a minimum value is achieved presumably connected with the location of cessation of boiling and completion of nucleation as main interaction mechanics of energy exchange. After that point, mechanical and evaporation mechanisms become the main driving mechanisms for energy exchange instead. The position at which the minimum temperature occurs is known as Minimum Temperature Distance (MTD). Previous works have not report major observations on this particular parameter. However, other related concepts as Cold Spray Distance (CSD), which refers to the spray distance where the spray maintains a specific temperature considered "cold" and the Spray Thermal Length (STL) refers to a total spray length where liquid droplets exist [54]. Similar behavior of the temperature profiles at the centerline has been observed several experimental settings [55–58]. Geometrical characteristics as diameter of the nozzle, length of the nozzle in the experimental system have influence on the dynamics behavior of the system, driving the velocity profile as well as the temperature profile. Evaporation and convection processes are also involved and their relevance along the leaking fluid properties as well as the characteristics of the jet is not well determined yet. Even so, in more recent works, some authors applied the jump condition analysis to the shock waves in the discharge of a superheated liquid [59]. Due to the metastable liquids supply the energy stored within them via the latent heat of vaporization, the evaporation wave was assumed as an adiabatic phase transition.

#### **4.2. Identification of key parameters for sensing technology: viability for sensing based on the concept**

**4.1. Theoretical basis of the problem: phenomenon involved**

industry [49, 51, 52].

60 Recent Advances in Porous Ceramics

velocity profiles [53].

Flashing depends on the initial parameter values of the fluid as pressure and temperature as well as the type of fluid. A particular combination of those variables can create, for some cases, a complete breaking of the liquid core into droplets at the same time that it is going out of container like unstable two phase jet or liquid jet. The major difficulty in the understanding of this flashing phenomenon and the parameters interactions within it belongs to the existence of a compromise between the physical and thermodynamics mechanism that acts on the released fluid [50]. Specific behavior and characteristics of these liquid-gas mixtures and the potential for the formation of vapor-liquid aerosols during a superheated liquid release due to the breaking of the metastable state can significantly affect the hazard zone and the mitigation steps that can be taken to minimize the release impact for the hydrocarbon

High complexity level of the whole process in combination with the need of more information based on experimental, analytical, or numerical models is the main difficulty to be overcome in order top developed new sensing technology. Different authors have concentrated efforts of the jet characterization. The developed information about the jet can help to understand the

Flashing phenomenon complexity required calculation of the velocity discharge, void fraction, and mass flow of a flashing jet together with the estimation of the temperature. Due to the nature of the nucleation process, the assumptions of adiabatic flow with non-reversible work for the surface tension forces are made. Those considerations are found to be more realistic that the isentropic condition used until now by different authors. Dynamics conditions usually considered include the mixture velocity after flashing as critical conditions. Frequently numerical modeling techniques are only applied after the flashing jet is formed. No droplets generation or vapor generation are included in the modeling. Droplets are imposed as part of the boundary condition of a gas jet. Droplets transport mechanics and their interaction and momentum exchange with the gas current is made using droplet interaction models as for example Disperse Model (DDM). Geometrical aspects as nozzle dimension, as well as, turbulent model used have a large impact on the core region length of the velocity profile. The numerical results are compared based on the centerline or cross section

In general, centerline, the temperature profile presents an initial decay from the exit of the nozzle until a certain distance, where a minimum value is achieved presumably connected with the location of cessation of boiling and completion of nucleation as main interaction mechanics of energy exchange. After that point, mechanical and evaporation mechanisms become the main driving mechanisms for energy exchange instead. The position at which the minimum temperature occurs is known as Minimum Temperature Distance (MTD). Previous works have not report major observations on this particular parameter. However, other related concepts as Cold Spray Distance (CSD), which refers to the spray distance where the spray maintains a specific temperature considered "cold" and the Spray Thermal Length (STL) refers to a total spray length where liquid droplets exist [54]. Similar behavior of the temperature profiles at the centerline has been observed several experimental settings [55–58].

parameters that can be used as key indicators of accidental release of hydrocarbons.

As direct consequence of the understanding of the process, it is possible to evaluate the potential of different variables or parameters to detect in the best possible way any leak, keeping in mind that the primary purpose of leak detection systems is to assist pipeline operators in detecting and locating leaks. The first aspect to consider is the magnitudes of the scale of mass discharge, the critical explosion limits, change in temperature of the surrounding, the time scale of the process, or any other parameters that be used to catch this phenomenon. Mass discharge directly seems to be no a convenient parameter to be measured directly but based on the amount of mass going out concentration of the leaked fluid in the surrounding will change. As described, this variable will depend on several physical parameters such as pressure difference, temperature, and fluid properties that will determine the discharge velocity.

Time scale of the leak is related with the jet velocity; however, the thermodynamics process of phase change are under the influence of another parameter as the fluid properties, which can be described based on the temperature variation along the centerline of the yet. Initially, there is a time lag of the initiation of flashing, followed by a drop of temperature driven by a phenomenon of sudden change of phase and finally an increment of the temperature to the ambient condition driven mainly by the mechanics mechanism of energy exchange. Characteristics of centerline droplets temperature of a R134a flashing jet by using and exponential function, which started with an almost exponential decay with the fastest drop in the temperature taking place near the nozzle exit, explained by the presence of rapid evaporation of the droplets and the insufficiency of the convective heat transfer from the surrounding [54]. This exponential decay of droplets average temperature can be described by an exponential function followed by less rapid temperature decay. Meanwhile, experimental data have pointed out that for different substances that there is a visible minimum in the temperature profile that can be related with the factor the mechanics mechanisms take over the thermodynamics mechanics of energy exchange [60]. Mentioned time scales are not commonly reported, however, it is possible to be calculated using the equilibrium model [61].

A different approach described that the flashing process can be detected based on the fact that rapid vaporization or phase change of superheated fluid produced an acoustic pulse that can detect by an acoustic sensor [62, 63]. Nucleation of vapor bubble requires a minimum amount of energy related to the vibrating media that will be traduced in pressure waves (noises). As mentioned in Section 3, the ceramics porous materials (e.g., catalytic and MOS sensors) are other available options for sensing hydrocarbon vapors and this will be discuss in details on the next section.


**4. Discussion**

The results of this study can be summarized as four types: (1) derivation of the approximate analytical solution; (2) validation of the solution against different numerical models; (3) introducing a step-by-step procedure to predict the values of physical parameters; (4) application of the analytical model in the field case.

Result 1 is one of the novelty of the article. The model contains three regions and effectively accounts for non-Darcy flow in the hydraulic fractures, and gas adsorption and slippage in the matrix. During the derivation process, the governing PDEs are transformed into ordinary differential equations (ODEs) by integration, instead of the Laplace transform. There is no doubt that Laplace transform works extremely well. However, there are still some problems: (1) the first step for Laplace transform is dimensionless transformation. For some dimensionless variables such as dimensionless time, dimensionless pressure, dimensionless production, and so on, more inputs are needed and many are even estimated, which will lead to calculation error. (2) The numerical inversion is an essential step for converting Laplace space into real-time space. Among them, Stefest numerical inversion algorithm is most commonly used. In this algorithm, the number of inversion items *N* is uncertain. The improper value will result in deviations in real time. Certainly, Result 1 also has some imperfections. For example, a dual-porosity model with Knudsen diffusion [6] would be more representative and the heterogeneity deserves further study.

Result 2 is the key section in the article. Seven numerical cases were set for verification. According to the fitting results, it shows that the analytical solution is feasible for the irregular and asymmetric stimulated regions in a multifractured horizontal well. Considering that the shapes of the enhanced fracture regions are unknown in real cases, we creatively set three types of stimulated regions: regular region, irregular region, and very irregular region. At least, the validation results show that our model is robust.

Result 3 is another novelty of our work. It introduced a step-by-step procedure to calculate inversion parameters. Comparing with the given volumes and calculated volumes from case 1 to case 7, the model is also verified to meet the engineering requirements. Considering the simplifying assumptions, the model may need to be improved and the accurate microseismic data would be required to make further verification.

Result 4 is the most important section. Considering the decline characteristics of shale gas, the constant rate case is not as important as the constant pressure case for long term performance of tight/shale formations. Therefore, our model is derived based on the constant bottom-hole pressure

condition, and namely one of limitations for our model is that it cannot be applied in a constant rate case. The second limitation is the data continuity, because the prerequisite for the model to make accurate prediction is great fitting. As for the discontinuous data like data missing, shut-in, or pressure/production jump, our model is not applicable. Combined with the assumption of single-phase flow in this work, the multiphase flow problem cannot be solved by this analytical solution. Gas–water two-phase flow is the most common in shale gas reservoirs, so our future work is to derive the new analytical solution for gas–water two-phase flow.