**9. Conclusion**

Our study provided further insight into the mechanism of aseptic loosening of hip arthroplasty. The most interesting aspect of this study is the evidence of elevated production of ROS, which are known to cause tissue fibrosis and may help explain the initiation of aseptic loosening. We feel that the thick pseudocapsule around loose prostheses is not an adaptive but a reactive tissue as a result of decreased degradation and increased formation of collagen matrix and proliferation of fibroblasts due to high oxidative stress. Furthermore, we demonstrated that elevated oxidative stress is associated with aseptic loosening of hip arthroplasty, suggesting that oxidative stress might induce periprosthetic osteolysis and subsequent loosening. Research in this line may help introducing new strategies for therapeutic prevention and/or treatment of osteolysis and subsequent aseptic loosening of total hip arthroplasty.


**10. Education and research**

Finally, education and awareness regarding orofacial clefts are key factors in achieving better long-term global access to cleft care. Education in cleft care is conducted at two levels:

#### **(a) Education of parents and caregivers**

Educating the care givers of cleft patient is crucial in achieving proper care and satisfactory future outcomes. On the initial visit, caretakers of the children should be given instructions on feeding assistance, airway maintenance, and other basic cleft care information to help the patient prepare for surgical intervention. After the operation, families should be given strict instructions regarding the remainder of their post-operative care at home prior to discharge. Families must be educated on the need for follow-up after operations and the importance of regular visits to the craniofacial orthodontist, pediatrician, speech therapist and feeding specialist for the long-term.

#### **(b) Training and education of local professionals**

It has long been the aim of global health care organizations to provide educational and training opportunities to health care professionals of LMIC, who can thereafter deliver high quality, team-based care in their local regions. A number of approaches have been outlined and proven to be effective in accomplishing this goal:

#### • **On-site education**

Delivering knowledge to local professionals on-site during cleft missions is effective in transmitting small, focused, and discrete areas of knowledge and experience. Although enormously enriching, such short-term programs provide a rather limited introduction to cleft care and surgery to local professionals present at the time [6].

#### • **Long-term education and training**

Long-term partnerships between local hospitals and academic institutions in wealthy countries help to provide proper, professional education, and experience. This can either be achieved by allowing fully credentialed visiting surgeons to stay with a host hospital and teach for an extended period of time or by bringing a limited number of host country participants to educational programs in regions with well-established craniofacial centers. More robust academic partnerships can also promote local academic leaders and would enhance training for health care providers in other fields, including speech pathology and surgical technicians. Such training programs aim to provide much needed local cleft care experts, who can contribute to the development of sustainable, self-sufficient cleft care centers.

#### **(c) Clinical research**

Collection of prospective, standardized data can yield high quality information that can be used to improve overall knowledge, cleft care processes, and outcomes. In addition to contributing to the field, research results can be presented to local health care professionals and the general population. Research can broadly be categorized as: epidemiological, genetic, prevention/risk factors, clinical presentation, outcomes assessment, and quality of life.


**Leonardo Clavijo 1,\* , Slobodan Zlatanovic 2, Gerd Braun 3, Michael Bongards 2, Andrés Dieste 1 and Stéphan Barbe 4**

Received: 26 February 2020; Accepted: 16 March 2020; Published: 24 March 2020

**Abstract:** Pelleted biomass has a low, uniform moisture content and can be handled and stored cheaply and safely. Pellets can be made of industrial waste, food waste, agricultural residues, energy crops, and virgin lumber. Despite their many desirable attributes, they cannot compete with fossil fuel sources because the process of densifying the biomass and the price of the raw materials make pellet production costly. Leaves collected from street sweeping are generally discarded in landfills, but they can potentially be valorized as a biofuel if they are pelleted. However, the lignin content in leaves is not high enough to ensure the physical stability of the pellets, so they break easily during storage and transportation. In this study, the use of eucalyptus kraft lignin as an additive in tree-leaf pellet production was studied. Results showed that when 2% lignin is added the abrasion resistance can be increased to an acceptable value. Pellets with added lignin fulfilled all requirements of European standards for certification except for ash content. However, as the raw material has no cost, this method can add value or contribute to financing continued sweeping and is an example of a circular economy scenario.

**Keywords:** eucalyptus kraft lignin; tree leaf; pellet; additive; biofuel; circular economy


**11. The NFκB (NF-kappaB) pathway**

The NFκB family in mammals contains 5 members – p105/p50 (NFκB1), p100/p52 (NFκB2), RelA (p65), RelB and c-Rel (J-206, 207). The canonical activation of NFκB pathway involves TNFα stimulation resulting in the subsequent phosphorylation/activation of IKK (IκB kinase). In turn, IKK-mediated phosphorylation of IκB leading to ubiquitination of IκB and its proteosomal degradation, releasing the NFκB complex which activates a host of target genes [116,117]. The type of genes that get trans-activated depends on the composition of activated NFκB complex. For instance, complexes containing c-Rel activates pro-apoptotic genes (Dr4/ Dr5, Bcl-x) and inhibits anti-apoptotic genes (cellular inhibitor of apoptosis (cIAP1, cIAP2), survivin). Complexes containing RelA inhibits the expression of DR4/DR5 and upregulates caspase 8, cIAP1 and cIAP2 [118].

NFκB is activated in various tumors including melanomas and distinct mechanisms have been proposed for the elevated levels of NFκB activity in melanomas. Activation of NFκB in melanomas is also linked to the loss of E-cadherin, a frequent event in melanoma transforma‐ tion [119]. NIK (NFκB interacting kinase), an activator of IKK is overexpressed in melanoma cells while compared to normal cells. The major contribution of NFκB in melanoma develop‐ ment and progression relates to its function as an important regulator of survival and apop‐ tosis. A study by Meyskens at al demonstrated that in metastatic melanoma cells, an increase in DNA binding activity of NFκB is associated with an increased expression of p50 and RelA resulting in increased expression of anti-apoptotic regulators. Also the expression of c-Rel, the transcriptional activator of pro-apoptotic genes is markedly in melanoma cells compared with normal melanocytes [120]. Strong p50 nuclear staining also correlated with poor prognosis in melanoma patients [121]. Besides eliciting anti-apoptotic activities NFκB mediates the transcription of MMP2 and MMP9 [121,122]. Overexpression of MMPs is associated with tumor invasion, metastasis and angiogenesis.


**3. Experimental work**

Experimental work starts with the preparation of work pieces to be joined. Each work-piece of the base material of size 300 × 150 × 6.35 mm by power hacksaw cutting and milling. Configuration of the square butt joints is prepared to make FSW joints. The unique joint configuration is achieved by using mechanical clamps to secure the plates in place. The welding direction is normal for the rolling direction. The joints are manufactured using a single pass welding procedure. Non-consumable tools made of tungsten carbide material are utilized to fabricate the joints. **Tables 1** and **2** show the chemical composition and mechanical characteristics of base metal.

**Vertimach V-350**. Vertical Machining Centre is used to fabricate the required joints**.** Three distinctive tool pin profiles are utilized to create the joints as appeared in **Figure 3** and nearly 81 joints are manufactured to study the impact of tool pin profile, rotational velocity, welding velocity and axial force on stir welded AA6061 aluminum alloy tensile properties. **Table 3** shows the levels of the experiment based on the Taguchi method. The experimental results are shown in **Tables 4–6**.

**137**

*Experimental Investigations on AA 6061 Alloy Welded Joints by Friction Stir Welding*

**Mn Si Fe Cu Cr Zr Mg Ti Al** 1.2 0.8 0.7 0.4 0.35 0.25 0.15 0.15 Balance

> **Elongation (%)**

276 310 18 12.24 105

**Reduction in crosssectional area (%)**

**Hardness (VHN)**

Using power hacksaw, the welded joints are sliced and then tensile specimens are machined to the necessary sizes. Guidelines for the preparation of sample samples are followed by the American Society for Testing of Materials (ASTM). In 400 KN, Electro-Mechanical Controlled Universal Testing Machine Tensile test has been carried. The specimen is recorded when the neck fails and the load versus the displacement. Charpy Impact Test is also conducted for the specimens. The Rockwell Hardness Test is conducted by indenting the test material with a diamond cone indenter. The indenter is compelled into tare using a Light Optical Microscope (Make: NIKON-LV 150) built into an Image Analysis Software. The specimens for metallographic examination are divided into FSP, TMAZ, HAZ and base metal areas according to the necessary dimensions. The samples are polished using various grades of emery documents. Final polishing is performed in the Disc Polishing Machine

**Process parameters Symbol Units Level 1 Level 2 Level 3** Tool rotational speed N rpm 1200 1600 2000 Welding speed S mm/min 48 60 72 Axial force F KN 1.5 2.0 2.5

*DOI: http://dx.doi.org/10.5772/intechopen.89797*

*AA6061 alloy (weights %) chemical composition.*

**Ultimate strength (MPa)**

**Table 1.**

**Table 2.**

**Figure 3.**

**Table 3.**

*Tool pin profiles of FSW.*

*Important factors and their levels for AA6061.*

**Yield strength (MPa)**

*AA6061 mechanical characteristics.*

*Experimental Investigations on AA 6061 Alloy Welded Joints by Friction Stir Welding DOI: http://dx.doi.org/10.5772/intechopen.89797*

#### **Table 1.**

*Aluminium Alloys and Composites*

defect-free FSP is very limited.

parameters

**Figure 2.**

joints.

**3. Experimental work**

because of the heat produced by the friction and the metal flow through the stirring action. On the other hand, owing to incorrect metal flow and inadequate metal consolidation in the FSP region, FSW Joints are susceptible to other defects such as cracks, tunnel defect, kissing bond, piping defect, pin hole, etc. Existing literature focuses on the impact of welding parameters and tool profiles on the formation of

*Different regions of FSW joint. A = unaffected metal base; B = Heat Affected Zone (HAZ); C = Thermo-*

**Objectives of this present work**: a Solemn attempt is made in the present investigation to conquer the limitations identified and to conduct experimentation

1.To fabricate FSW joints with different tool pin profiles and identify the process

2.Investigation of the impact of tool pin profile and welding parameters (rotational speed, welding speed and axial force) on the formation of defect-free FSP as well as on tensile, impact properties and the hardness of the welded

3.The ANN modelling of the process and to attain maximum tensile strength and

Experimental work starts with the preparation of work pieces to be joined. Each work-piece of the base material of size 300 × 150 × 6.35 mm by power hacksaw cutting and milling. Configuration of the square butt joints is prepared to make FSW joints. The unique joint configuration is achieved by using mechanical clamps to secure the plates in place. The welding direction is normal for the rolling direction. The joints are manufactured using a single pass welding procedure. Non-consumable tools made of tungsten carbide material are utilized to fabricate the joints. **Tables 1** and **2** show the

**Vertimach V-350**. Vertical Machining Centre is used to fabricate the required joints**.** Three distinctive tool pin profiles are utilized to create the joints as appeared in **Figure 3** and nearly 81 joints are manufactured to study the impact of tool pin profile, rotational velocity, welding velocity and axial force on stir welded AA6061 aluminum alloy tensile properties. **Table 3** shows the levels of the experiment based

on the Taguchi method. The experimental results are shown in **Tables 4–6**.

4.Evaluation of the microstructure of FSP zone for different pin profiles.

on AA6061 Al alloys with the objectives as given in the following:

*Mechanically Affected Zone (TMAZ); D = Friction Stir Processed (FSP) zone.*

analysis of variance for optimal process parameters.

5.Conducting the SEM analysis to analyse the flow of material.

chemical composition and mechanical characteristics of base metal.

**136**

*AA6061 alloy (weights %) chemical composition.*

#### **Table 2.**

*AA6061 mechanical characteristics.*

#### **Figure 3.**

*Tool pin profiles of FSW.*

#### **Table 3.**

*Important factors and their levels for AA6061.*

Using power hacksaw, the welded joints are sliced and then tensile specimens are machined to the necessary sizes. Guidelines for the preparation of sample samples are followed by the American Society for Testing of Materials (ASTM). In 400 KN, Electro-Mechanical Controlled Universal Testing Machine Tensile test has been carried. The specimen is recorded when the neck fails and the load versus the displacement. Charpy Impact Test is also conducted for the specimens. The Rockwell Hardness Test is conducted by indenting the test material with a diamond cone indenter. The indenter is compelled into tare using a Light Optical Microscope (Make: NIKON-LV 150) built into an Image Analysis Software. The specimens for metallographic examination are divided into FSP, TMAZ, HAZ and base metal areas according to the necessary dimensions. The samples are polished using various grades of emery documents. Final polishing is performed in the Disc Polishing Machine

#### **Table 4.**

*Optimum parameters for the threaded pin profile.*

#### **Table 5.**

*Optimum parameters for the conical pin profile.*

#### **Table 6.**

*Optimum parameters for the triangular pin profile.*

using the diamond compound (1 mm particle size). Specimens are etched with the Keller's reagent, to reveal the macro and micro structures. SEM analysis is conducted using the Scanning Electron Microscope. SEM produces a range of signals exterior of sample specimens by utilizing the high energy focused electrons. Signals derived from SEM reveal information on the sample, including exterior morphology (texture), chemical composition, crystalline structure and orientation of the sample material.


**1. Introduction**

The term "cosmetic" has its origin from the Greek term "kosme'tikos," a noun to denote the art of beautifying the body [1]. Since ancient times, humans have searched for materials and developed many products to mainly enhance female beauty. Over the centuries, cosmetics have been developed and influenced by different ethnic traditions, from the times of the Pharaohs to the modern times [2]. Since then, physical appearance has been an inseparable part of daily human existence, improving their self-image and self-esteem. However, the esthetic concept of beauty has changed overtime, and beauty standards have been modified according to many factors such as social, ethnic, and religious belief influences [2]. Personal hygiene has been also part of human life since the ancient times. Traditionally related to hygiene habits during religious activities, the preparation of food, or the

#### **Table 1.**

*Most used cosmetics and personal care products.*

prevention of diseases, hygiene practices have also greatly changed through the cultures and eras, from bathing facilities in the Roman period to modern synthetic products such as body lotions or hair tonics [3].

In the last years, the variety of cosmetics and personal care products (PCPs) have greatly increased (**Table 1**), in parallel to their manufacturing and consumption volumes in developed and developing countries. For example, the consumption of cosmetics and perfumery in Spain has consecutively increased in the last years, reaching a total of 1280 million units sold of these products and 770 million units exported during 2018. To date, the USA is the leader in the consumption of cosmetics and perfumery, with an amount of 78.6 billion euros, followed by China (52 billion euros), Japan (32 billion euros), and Brazil (28 billion euros) [4]. Despite the current beauty standards are not similar along cultures and ethnicities, it is acknowledged that women have a greater use of cosmetics and personal care products (PCPs) when compared with men [5], and therefore, potential adverse effect may affect predominantly to this population.

**Table 1** summarizes the main types of cosmetics and PCPs commonly used worldwide.


*Supporting open minds since 2005*

Vectors and Vector-Borne Zoonotic Diseases http://dx.doi.org/10.5772/intechopen.77985 Edited by Sara Savić

#### Contributors

Iva Christova, Roberto Badaro, Daniel Motta, Frank Kirchner, Alex Santos, Nazli Ayhan, Remi N. Charrel, Biswadeep Das, Sayam Ghosal, Swabhiman Mohanty, Ana Sofia Santos, Maria Margarida Santos-Silva, Mümtaz Güran, Sara Savic

#### © The Editor(s) and the Author(s) 2019

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#### Notice

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First published in London, United Kingdom, 2019 by IntechOpen eBook (PDF) Published by IntechOpen, 2019 IntechOpen is the global imprint of INTECHOPEN LIMITED, registered in England and Wales, registration number: 11086078, The Shard, 25th floor, 32 London Bridge Street London, SE19SG – United Kingdom Printed in Croatia

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*2.1. BRA*

The BRA was produced from the waste residues during the production of cooking oil, and is a sustainable regenerative agent for aged bitumen; it was supplied by the Wuhan Daosheng Transportation Technology Co., LTD, Wuhan, China. The technical parameters of the BRA are shown in Table 1.

**Table 1.** Technical parameters of BRA.

#### *2.2. Mix Design of BRA-Rejuvenated RAP*

The RAP was crushed and divided into four grades of 10–15 mm, 5–10 mm, 3–5 mm, and 0–3 mm; the size distribution of each grade of RAP is shown in Table 2. The bitumen contents of different sizes of RAP aggregates are shown in Table 3. The actual bitumen content of the RAP mix was 4.5%.

**Table 3.** Bitumen contents of different sizes of RAP aggregates.

The low dosages of new bitumen and epoxy resin were applied as the enhancement additives, in an effort to improve the mechanical properties and road performance of the BRA-rejuvenated RAP. The dosages of new bitumen and epoxy resin are shown in Table 4. The ratio of additives was measured by the weight of the RAP.

**Table 4.** The dosages of new bitumen and epoxy resin.

#### *2.3. Chemical Structure Analysis Tests*

The Fourier-transform infrared spectrometer (*FTIR,* NICOLET 6700 FLEX, Thermo Fisher, Waltham, MA, USA) was used to determine the chemical structure of unaged bitumen, aged asphalt, BRA, and BRA-rejuvenated RAP. The testing specimens were prepared at a ratio of 1:20 with carbon disulphide (CS2) solution according to the film method in GB/T 6040-2019, pressed into shape, and then subjected to FTIR spectroscopy. The scanning spectral wavenumber range of the test instrument was from 4000 cm−1 to 400 cm−1.

#### *2.4. Molecular Weight Distribution Tests*

Gel permeation chromatography (GPC, Agilent PL-GPC50, Varian, PaloAlto, Santa Clara, CA, USA) was used to measure the molecular weight distribution of the BRA. Firstly, 0.4 mg of BRA and 2 mL of tetrahydrofuran solution were placed in the bottle; then, the sample solution was filtered into the test glass container using a filter with a 0.45 μm pore size microporous filter membrane, and then 50 μL of the sample was injected into the injector. The flow rate of the solution through the gel column was 1 mL/min.

#### *2.5. Mixing and Indoor Regeneration of BRA-Rejuvenated RAP*

The different grades of RAP were mixed according to the mix design of the BRArejuvenated RAP, and then the BRA was added to the mixing machine and mixed for 120 s. The mixing temperature was atmospheric temperature. Then, the mixture was stored at atmospheric temperature for 24 h to allow the aged bitumen to be fully activated by the BRA. After 24 h, the epoxy resin was added to the BRA-rejuvenated RAP for a second mixing, with a mixing time of 90 s. The mixture was then used to manufacture the test specimens. The Marshall specimens of BRA-rejuvenated RAP were mixed in the same way as commonly used dense-grade HMA, and the specimens were compacted 75 times for each side. The specimens were cured at 40 ◦C for 2 days. For the BRA-rejuvenated RAP with enhancement additives (new bitumen or epoxy resin), firstly, the new bitumen was heated to 130 ◦C, and then the BRA was added to the melted bitumen; we then used a high-speed shearing machine to stir the mixture for 15 min. The BRA-modified bitumen was manufactured to regenerate the RAP. The low viscosity of the BRA-modified bitumen ensured that it could mix freely with the RAP at room temperature.


*2.3. Calculation of Environmental Factors and Instantaneous Fresh Weight* 2.3.1. Calculation of Cumulative Radiant Heat Product

The effects of temperature and radiation on the fresh weight of lettuce can be measured by the cumulative radiant heat product. The specific calculation formula is as follows [26]:

$$R\_{TE} = \begin{cases} 0 & (T < T\_b) \\ \frac{T - T\_b}{T\_{ob} - T\_b} & (T\_b \le T < T\_{ob}) \\ 1 & (T\_{ob} \le T \le T\_{ou}) \\ \frac{T\_m - T}{T\_m - T\_{ou}} & (T\_{ou} < T \le T\_m) \\ 0 & (T > T\_m) \end{cases} \tag{1}$$

$$T\_{EP} = \sum R\_{TPP} \tag{2}$$

$$R\_{TPP} = \sum\_{i=1}^{24} \left( R\_{TEi} \times P\_{ARi} \times 3600 / 10^6 \right) \tag{3}$$

where *Tb* is the lower limit of growth temperature (◦C), *Tm* is the upper limit of growth temperature (◦C), *Tob* is the lower limit of optimum growth temperature (◦C), *Tou* is the upper limit of optimum growth temperature (◦C), *T* is the ambient temperature (◦C), *RTE* is the relative thermal effect, *RTEP* is the daily cumulative radiant heat product (MJ·m−2·d−1), *RTEi* is the relative thermal effect in the *i*-th hour, *PAri* is the average photosynthetically active radiation in the *i*-th hour (MJ·m−2·d−1), and *TEP* is the cumulative radiation heat product (MJ·m−2).

#### 2.3.2. Calculation of Crop Evapotranspiration

If reference evapotranspiration is used to replace crop evapotranspiration, there will be a large error. Therefore, in order to improve the accuracy of calculation of crop evapotranspiration, the crop coefficient was used to correct the reference evapotranspiration. The specific calculation formula is as follows [27]:

$$ET\_{\mathfrak{c}} = ET\_0 \cdot \mathbf{K}\_{\mathfrak{c}} \tag{4}$$

$$ET\_{0i} = \frac{0.408\Delta (R\eta - G) + \gamma \frac{1713}{T + 273} (e\_s - e\_a)}{\Delta + 1.64\gamma} \tag{5}$$

$$\Delta = \frac{2505 \cdot \exp\left(\frac{17.27T}{T + 237.3}\right)}{\left(T + 237.3\right)^2} \tag{6}$$

$$e\_s = \frac{e\_s(T\_{\text{max}}) + e\_s(T\_{\text{min}})}{2} \tag{7}$$

$$e\_s(T\_{\text{max/min}}) = 0.6108 \cdot \exp\left(\frac{17.27 T\_{\text{max/min}}}{T\_{\text{max/min}} + 237.3}\right) \tag{8}$$

$$e\_a = \frac{e\_s \left(T\_{\rm min}\right) \frac{RH\_{\rm max}}{100} + e\_s \left(T\_{\rm max}\right) \frac{RH\_{\rm min}}{100}}{2} \tag{9}$$

$$R = K \cdot P\_{AR} \tag{10}$$

$$R\_n = a \cdot R + b \tag{11}$$

where *ET0* is the reference evapotranspiration under full irrigation (cm·d−1), Δ is the slope of the saturated vapor pressure curve (kPa· ◦C−1), *Rn* is the net radiation of the crop canopy (MJ·m−2·d−1), *G* is the soil heat flux density (MJ·m−2·d−1), *γ* is the dry and wet table constant (kPa· ◦C−1), *T* is the daily average temperature at the height of 1.5 to 2.5 m above the surface (◦C), *Tmax/min* is the daily maximum or minimum air temperature at the height of 1.5 to 2.5 m above the surface (◦C), *es* is the average saturated vapor pressure at the height of 1.5 to 2.5 m above the surface (kPa), *ea* is the average actual vapor pressure at the height of 1.5 to 2.5 m above the surface (kPa), *RHmax/min* is the daily maximum or minimum relative humidity at the height of 1.5 to 2.5 m above the surface (%), *ETci* is the evapotranspiration of crops on the *i*-th day under full irrigation (cm/d), *Kc* is the crop coefficient, *R* is the total solar radiation (MJ·m−2·d−1), *PAR* is the photosynthetically active radiation (MJ·m−2·d−1), *K* is the conversion coefficient between photosynthetically active radiation and total solar radiation, and a and b are the conversion coefficients between net radiation and total radiation.

If *G* = 0, *γ* = 0.067, *Kc* = 0.7, 1.00 or 0.95 [28], *K* = 80/39 [29], a = 0.8277, and b = 0.2909 [30], then *ETc* can be calculated using Formulas (4)–(11) and the indoor temperature, humidity, and photosynthetically active radiation.

#### 2.3.3. Calculation of Instantaneous Fresh Weight and Fresh Weight Increment

Based on the previous research results of this research group [24], the online, nondestructive calculation of the fresh weight of substrate-cultivated lettuce grown in a solar greenhouse was realized by combining the data of phenotypic characteristics and environmental characteristics. Firstly, the collected lettuce canopy images were used to extract phenotypic characteristics such as shape, color, and texture. Then, using the online monitoring values of temperature and photosynthetically active radiation, cumulative radiant

heat product was calculated as an environmental factor. Finally, the above factors were introduced into the model for fresh weight estimation of substrate-cultivated lettuce grown in a solar greenhouse, and the instantaneous fresh weight of the lettuce was obtained (Figure 2). The fresh weight increment was obtained by subtracting the instantaneous fresh weight at one time point from another.

**Figure 2.** Schematic diagram of calculation of instantaneous fresh weight.


**5. Conclusions**

The present study examined the occurrence of the major insect pests of quinoa and their natural enemies in a traditional production zone in the Andean region (San Lorenzo), and two non-traditional areas for quinoa production in Peru at lower elevations (La Molina, on the Coast, and Majes, in the "Maritime Yunga" ecoregion). The data gathered by on-plant and pitfall sampling show that the pest pressure in quinoa is higher at the lower altitudes than in the highlands of Peru. Although there are better conditions in the non-traditional quinoa production zones for attaining higher yields than in the Andean region, pests are likely to become an important barrier for successful quinoa production, a situation that may worsen if pesticides are incorrectly used. These are issues that farmers from Peru, and other South American countries, will eventually face when exploiting new production areas. Studies on the biology and ecology of the key species of pests and their natural enemies will aid in implementing suitable pest control strategies for the crop. Particularly, additional studies are needed to clarify the potential risks of aphids and *F. occidentalis* for quinoa production, especially in the non-traditional zones.

**Supplementary Materials:** The following are available online at http://www.mdpi.com/2077-0472/10/12/644/s1. Figure S1: Localities of La Molina, San Lorenzo and Majes in the map of Peru, Figure S2: Fluctuation of the daily mean temperature (maximum and minimum) and daily precipitation during the sampling period in La Molina–Lima, San Lorenzo–Junín and Majes–Arequipa.

**Author Contributions:** Conceptualization, L.C., E.d.l.P. and P.D.C.; methodology, L.C. and P.D.C.; investigation, L.C., E.d.l.P. and P.D.C.; formal analysis, L.C., E.d.l.P. and P.D.C.; data curation, L.C.; writing—original draft preparation, L.C.; writing—review and editing, L.C., E.d.l.P. and P.D.C.; supervision, E.d.l.P. and P.D.C. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was funded by THE PROJECT 2: "Development of Value Chains for Biodiversity Conservation and Improvement of Rural Livelihoods"—Sub Project: Native Grains, VLIR-UOS IUC/UNALM.

**Acknowledgments:** We thank Daniel Burckardt from the Naturhistorisches Museum of Switzerland for confirming the identity of the psylloids and Pablo Dellapé from the Museum of La Plata in Argentina for confirming the identity of *Nysius simulans*. We also thank the professors from the National Agrarian University La Molina in Peru; Luz Gómez, chief of the Cereals and Native Grain programme; and Clorinda Vergara, chief of the Museum of Entomology "Klaus Raven Büller" for the facilities and permits. Finally, we acknowledge VLIR-UOS/UNALM for funding this study.

**Conflicts of Interest:** The authors declare no conflict of interest.


**2. New product development**

Product managers only manage the brands produced and introduced into the market. This goes to show that a company has to first develop a product or follow any legal means to acquire a product in order to sell it to the target market. For this reason, it may not be out of place if we appraise the ways through which a company obtains a product. A company can use any of the following ways to get a product, among others.

Out of the aforementioned ways of obtaining a new product, the main focus of this section is to discuss the process involved in developing a new product by a company.


Mahasthangarh. The Global Heritage Fund has identified Mahasthangarh site as one of 12 global sites most "On the Verge" of irreparable loss and demolition, quoting insufficient management and looting as primary reasons [9]. The daily round-like excavation, conservation, preservation, and proper monitoring is insufficient and cannot be done regularly. Based on site requirement, there is lack of an insufficient number of management workmen and a deficiency of skillful and experienced manpower, particularly in the area of conservation and preservation management. Insufficient management policy reduces integrity, authenticity, and future potentiality as a tourism area.

#### *3.2.4 Relationship among stakeholders*

Every project has stakeholders who can influence or be influenced by the project in a positive or negative manner [10]. To ensure a sustainable heritage management plan, all stakeholders must be in sync and aim to achieve a common goal. Proper coordination between all the concerned stakeholders who are playing key roles is not well coordinated presently. Participation of all of them only could ensure the success of achieving the common goal. As a developing country, necessary finance and infrastructure could only be maintained by all the stakeholders combined.

#### **3.3 Heritage awareness program and training issue**

Due to various bureaucratic complicacy and flaws inherited in the administrative structure, the policymaking person or the body is not properly trained and skilled in the necessary steps that are necessary for sustainable heritage management. Besides, the execution of a feasible and viable short- and long-term sustainable master plan depends on so many other variables also that need to be considered. The insufficient training and various skills-enhancing programs could not ensure the proper use of the existing human resources. On the other hand, a multitiered heritage awareness program is not planned for various leveled education institutes and local inhabitants.

#### **3.4 Conservation and preservation issues**

Insufficient archeological and historic testimony causes improper restoration of the different potential ruins. Apart from this, deficiency of appropriate research, insufficient of efficient conservators, and untrained workmen cause improper restoration, which can reduce the integrity and authenticity of the structure. Mankali Kundu Mosque, Porshuram's palace, and Rampart are the examples of improper restoration, where the modern brick used for restoration and conservation is not in a good condition.

#### **3.5 Environmental issues**

#### *3.5.1 Poor drainage*

Mahasthangarh is located on the high Barind track (Pleistocene land formation), which naturally has numerous natural drainage systems. But over time, due to the enormous modern urban expansion pressure/demand, the historical landscape has been changed with unplanned dwellings, canals, ponds, and various purposes. Long-standing waterlogging, high surface erosion, change in the microclimate, and untimed flooding are the few caused by the poor drainage, which deeply impacted the existing heritage sites. Currently, most of the archeological remains both excavated and unexcavated are buried at the citadel and ancient drainage is no longer in function that was originally interconnected to the river and surrounding moats.

#### *<IP_ADDRESS> Overgrowing vegetation*

Microclimate of Mahasthangarh area changed and subsoil water level, moisture content in the air, and even the use of harmful fertilizers and pesticides resulted in the overgrown weed type, different types of grasses, shrubs, moss, undulating, and sycophants roots are common vegetation problems, which cause damage to ancient bricks and diminish the intensity of structure. Apart from these, extensive sun heat, high winds, and earthquakes are one of the major threats to brick-built structures.

#### **4. Role of museum**

Presently, as like all site museums of Bangladesh, the Mahasthangarh site museum is solely under the administration of DoA. Site museums play key activities in heritage site management together with keeping education, research, cultural tourism, and description of museum objects [11]. Museums can cooperate with the heritage site management team by helping to safeguard and conserve the archeological heritage sites and monuments *in situ*, and preserving the records of *ex situ*, as well as promoting the archeological heritage through their displays, exhibition, and other programs [1]. But the site museum of Mahasthangarh is not coping with all of the objectives mentioned above.

The collections of museums can motivate communities, groups, and individuals to manage and preserve their tangible and intangible cultural heritage. In the context of Mahasthangarh, site museums could play a valuable role in the protection and promotion of the cultural heritage of Mahasthangarh through education, national or regional functions, and raising awareness in the society about the value of cultural

#### *The Role of Museums and Communities in Sustainable Heritage Site Management… DOI: http://dx.doi.org/10.5772/intechopen.109527*

heritage and the importance of safeguarding for the sake of present and future generations. It can arrange exhibitions and educational activities, such as gallery walks, seminars symposium, training workshops, and conferences with the collaboration of various institutions, stakeholders as well as local communities on a regular basis. Museums can use intangible heritage to develop a better understanding of their visitors. For these museums, there is a need to identify, document, and represent the intangible aspects of their collections. Social communities can use museums as cultural platforms to educate and communicate with their ancestors, improve the museums as a source of knowledge and education as well as progress the practice of protection and preservation of cultural heritage. There is need to enhance the capability of Mahasthangarh site museum officials, particularly in the area of museum management and cultural heritage management both tangible and intangible, predominantly on the basis of UNESCO and ICOM manuals and publications. It is highly necessary for museums and the local community to come together to reduce conflicts or misunderstandings, to safeguard against various threats as well as promote and preserve cultural heritage.

Mahasthangarh archeological museum is one of the major visitor attractions. It often faces excessive pressure on visitors, which is necessary for adequate management of visitors within the museum and other sites. Therefore, controlling is a key to keeping people at a safe distance.

#### **5. Role of community**

Community engagement has become a significant approach to protection, management, preservation, and improving both tangible and intangible heritages. Most of the archeological landscape in Mahasthangarh area is owned by the host communities and they are continuously demolishing. Apart from these, many heritage sites are unprotected and some are under the possession of a public authority.

A local site custodian of DoA is conducting site maintenance and management policies. The local community has become an essential part of the site because most of the community is an agrarian society around the heritage sites. There are a large number of tangible heritage sites and numerous intangible heritages that are partially practiced in Mahasthangarh region [12]. So, it can be safely said that, without community engagement, effective heritage management is quite impossible for the local custodians (**Figure 6**)*.*

The Burra Charter addressed that heritage conservation and management will become unsustainable without community/stakeholder engagement [13]. Every year, hundreds of thousands of people of several religions, both national and international, assemble here as part of their religious and traditional festivals and recreation. These kinds of religious and culturally renowned events are utterly involved with tangible heritage. The general vision for community engagement in the Mahasthangarh heritage sites is to ensure the local communities benefit from the safeguarding of the heritage, so that they can connect socially, culturally, or economically with "their" heritage sites.

In the context of a developing country, Bott *et al.* and Driscoll *et al.* experiment the four attributes of stakeholders, where they found every stakeholder has a high legitimacy and sole the local community retains all attributes at the high levels, along with they also found poorly relationship with other stakeholders due to deficiency of proper communication [14, 15].

#### **Figure 6.**

*Tomb of Mir Sayyid Sultan Mahmud Mahisawar of Mahasthangarh, one of the earliest Sufi saints of Bengal.*

#### **Figure 7.**

*Bar chart shows the profile of 250 individual respondents, who were interviewed from various sectors with formatted questionnaires.*

Local communities would like to participate in heritage management through village tourism, river tourism, and homestay program. For the unprotected and publicly owned heritage sites, it is of vital importance of public participation for

*The Role of Museums and Communities in Sustainable Heritage Site Management… DOI: http://dx.doi.org/10.5772/intechopen.109527*

these heritages for their demolition, and safeguarding against threats and challenges. Notwithstanding, community engagement in heritage management is a new concept in this region and can hardly be observed here in Bangladesh. DoA should have to start the effective implementation of the community engagement policy from Mahasthangarh (**Figure 7**).

#### **6. Discussion**

Collaboration, cooperation, and engagement of stakeholders are major issues in the heritage management planning process [12]. This research noted that sustainable heritage conservation and management have relied heavily on the active role of museums and engagement of the local communities, in particular, and other relevant stakeholders, in general. Most of the stakeholders, particularly the local community, did not get an invitation from the site manager (**Figure 8**). The site manager needs to prepare a preliminary list of stakeholders and their concerns about heritage sites. Khan details discussed the stakeholders and their possible roles in the heritage management activities of Mahasthangarh [16].

The present site manager of Mahasthangarh and DoA needs to incorporate with the local community through cooperation, dialog, involvement during the decision making, engaging in management activities, and respecting their demands. The same should be maintained for all stakeholders. The social, cultural, and economic benefits of site management and tourism activities should distribute equitably to the men and women of the existing local or host communities at all levels through training, educating, and creating employment opportunities. A significant portion of the revenue of heritage sites particularly comes from tourism should be allotted priority base to the site management activities, socioeconomic development, and poverty alleviation around the heritage site. Local college and school students would like to participate as heritage site interpreters and guides.

There is an urgent need to clearly identify the core zone and buffer zone boundary of the Mahasthangarh heritage site. The delineation of core zone and buffer zone boundaries is an essential requirement in the establishment of effective and

#### **Figure 8.** *The bar chart shows the results of "Yes" and "No" questions.*

sustainable protection of heritage properties. Boundaries should be drawn to incorporate all the attributes that convey the outstanding universal value (OUV) and to ensure the integrity and/or authenticity of the property [17]. DoA can develop a zoning system in the greater Mahasthangarh territory to provide effective protection to the ruins, including natural heritage, which makes up the cultural landscape to conserve and protect the esthetics values and OUV of the Mahasthangarh.

It is mentionable that in the citadel area, ancient settlements and monuments are located in the eastern part at the same alignment from the north rampart (Jahazghat site) to the south (Mazar area) (**Figure 2**). Primarily, in the context of a short-term plan, the DoA should protect this eastern part with a wall boundary and can develop tourism with a ticket system to earn revenue, which will manage the heritage perfectly. The regular site maintenance and monitoring activities can control and prevent theft, vandalism, and accidental unwitting damage in the Mahasthangarh citadel area as well as ensure the staff and visitors' safety. It is necessary to take plan and policy for the effective management of most potential heritage sites and should be well-planned and long-term policy with regular monitoring on the basis of the National Heritage Act and international standards.

Field assessments suggest local communities have a better understanding of which factors might be damaging to the archeological sites and monuments (**Figure 5**). If the people of the local community get the opportunity to join the site management team as an officer and understand the importance of the heritage sites of the Mahasthangarh, they will notice damaging activities and report such damage to the relevant authorities (museum/site manager). DoA should have to start the effective implementation of community engagement policy from the Mahasthangarh regions.

Every visitor naturally appreciates an amiable welcome and support with any accidental problems. The museum staff and guide need to treat visitors as guests to be welcomed and helped, along with having to protect them from theft or any unwitting damage. It is essential that facilities, including toilets, and shaded areas with seats should be provided. On the other hand, an interpretation center needs to be set up adjacent to the museum and should be made clearly visible to visitors arriving at the site. Most of the respondents don not know the informative history and importance of heritage safeguarding (**Figure 4**). There is a need to publish educational materials, such as Mahasthan children's books, leaflets, souvenirs, booklets, and general books, regarding the importance of heritage protection and make them obtainable at every site and the museum gate. For successful visitor management, firstly, site manager should identify visitors' expectations, needs, and satisfactions.

Interpretation, education, publication, and research are significant factors in effective and sustainable heritage management. The site manager with the help of DoA should establish a permanent research and training center at the site to properly interpret and regular publication with educational materials to provide visitors and research interests. Along with this, there is a need to set up long-term educational programs at and around the site and make sure local educational institutions (schools, college, university, and madrasha) benefit from these functions. The site manager also can develop different types of skills with effective training of the local artisan, handicraftsmen, guide, officer of the museum, and site management team as well as increase proper employment opportunities to enhance the socioeconomic condition of the existing communities around the sites. Almost every inhabitant coexists at the citadel and participates in heritage management through village/rural tourism (60%), *The Role of Museums and Communities in Sustainable Heritage Site Management… DOI: http://dx.doi.org/10.5772/intechopen.109527*

#### **Figure 9.**

*The bar chart shows the results of the question "how would you like to participate in the site management program if the DoA offers?"*

#### **Figure 10.**

*3D reconstruction model of the archeological complex of the Mahasthangarh citadel, showing the Karatoya River in the eastern side, and the moat surrounding the other three sides of the citadel [12].*

river tourism (60%), home stay program (50%), and guide (20%) (**Figure 9**), which will provide socioeconomic and infrastructural benefit to the local communities and regional government resulted in heritage, which will be protected from decay and damage. These tourisms could play an important role in poverty alleviation of Mahasthangarh area. Jahan discussed how and in what ways intangible heritage tourism can play an effective role to improve social benefits and community involvement in protecting and managing the cultural heritage of Bangladesh [18]. It is mentionable that any tourism in the Mahasthangarh area should remember that the main objective is to protect, promote, and manage the tangible and intangible heritage. There are numerous significant intangible cultural heritages that bear the testimony of esthetics and outstanding universal values that need to develop inventories and updated regularly (**Figure 10**) [12].

#### **7. Conclusion**

Mahasthangarh area is a huge village and river tourism potential for its charming landscape, massive rampart, river, and deep moat with marshland (**Figures 1** and **2**). The overlooked intangible heritage of Mahasthangarh could be promoted through village/rural tourism and river tourism. Generally, these types of tourism facilitate and promote the regional intangible heritage, such as folklores, handicrafts, traditional songs, dance, foods and games, and also indigenous culture. City dwellers and foreign tourists can enjoy rural culture by spending the night at the citadel area. The promotion, distribution, and sale of local produce, including handicrafts, Bogurar Doi (Yogurt of Bogura), Mahasthan Kotkoti (dry cracker biscuit), and other products should provide a reasonable social and economic return to the local community while ensuring that their intangible cultural heritage integrity is not degraded.

**Different types of fair festivals and religious festivals held at the bank of Korotoya River and the Tomb of Sufi saint Mahisawar** (**Figure 6**), **which have been conducted by the local communities without any assistance of DoA, where thousands of pilgrims gather every year from home and abroad.** Like many other Mosques and Tomb of Bangladesh, Mahasthangarh Mosque and Tomb are well managed and regularly monitored by local communities, contrariwise ancient mounds are damaging that is managed by only DoA. It is safely assumed that if DoA actively engages local communities through village and river tourism, the heritage of Mahasthangarh will be well managed. Most of the local community and some of the museum officials believe that village and river tourism could bring lots of benefits to the host community and can be an important mechanism for sustainable human development, including poverty alleviation, employment generation, development of rural areas, and progression of women and other disadvantaged groups resulted in local community that would be encouraged to safeguard archeological heritage from devastations for their interest. During the fieldwork, some important needs were identified following the conduct of some tourists. These are transports inside and around the citadel of Mahasthangarh, shady resting place, tourist guide with proper knowledge of the site, enough pure drinking water, safety against beggars, fraudsters, vagabonds, and local vendors.

Most of the respondents are unable to talk about Mahasthangarh without myth and legends; also, they are not aware of the importance of heritage safeguarding (**Figure 4**). Therefore, the heritage of Bangladesh and the importance of heritage protection need to include in the textbook through the national curriculum board.

#### *The Role of Museums and Communities in Sustainable Heritage Site Management… DOI: http://dx.doi.org/10.5772/intechopen.109527*

The present existing Antiquity Act 1968 (amended 1976) is not adequate to conserve and manage the heritage site of Bangladesh. The act should be revised to provide sufficient protection and sustainable management of heritage. The sustainable heritage site management of Mahasthangarh requires a work plan to operate the aims and objectives properly of the entire management activities step by step, and need to be developed annual, short-term (5 years), mid-term (up to 10 years), and long-term (25–30 years), and should be updated with revision.

### **Author details**

Mohammad Mahmudul Hasan Khan\* and Mohammad Niamul Huda Department of Archaeology, Comilla University, Bangladesh

\*Address all correspondence to<EMAIL_ADDRESS>
© 2023 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

#### **References**

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Sadequzzaman M. Tentatively listed two promising UNESCO World heritage sites of Bangladesh; Some observations and prospects of the present heritage management scenario. Journal of Bengal Art. 2021;**29**:673-689

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[5] Ahmed N. Mahasthan. Dacca: Department of Archaeology and Museums, Government of the Peoples' Republic of Bangladesh; 1981

[6] Sen PC. Mahasthan and its Environs. Varendra Research Society Monograph 2. Rajshahi: Varendra Research Society; 1929

[7] Salles FJ, Alam S. The Archaeology of Mahasthangarh: Historical and environmental perspectives. In: Salles FJ, Alam S, editors. First (& Second) Interim Report 1993-1999. France-Bangladesh Joint Venture Excavations at Mahasthangarh. Dhaka: Department of Archaeology; 2001/2018. pp. 1-18

[8] Rahman SM. Archaeological investigation in bogra district (from early historic to early medieval period). Dhaka: The International Centre for Study of Bengal Art; 2000

[9] Global Heritage Fund. Saving our vanishing heritage: Safeguarding Endangered Cultural Heritage Sites in the Developing World. Palo Alto: Global Heritage Fund; 2010

[10] PMI. A Guide to the Project Management Body of Knowledge (PMBOK-Guide). 6th ed. USA: Project Management Institute; 2017

[11] Brief P. Role of Museums in Education and Cultural Tourism Development. Kyiv: Ukrainian Committee of ICOM; 2012

[12] Khan MMH. Heritage Site Management of Mahasthangarh, Ancitent City of Bangladesh; Reappraisal Problems, Prospects and Propositions, unpublished [PhD thesis] Department of Archaeology, Dokuz Eylul University, Izmir, Turkey. 2021

[13] Charter B. The Burra Charter: The Australia ICOMOS Charter for Places of Cultural Significance. Australia: Burra; 2013

[14] Bott AL, Grabowski S, Wearing S. Stakeholder collaboration in a prospective world heritage area: The case of Kokoda and the Owen Stanley ranges. Cosmopolitan Civil Societies Journal. 2011;**3**(2):35-54. ISSN: 1837-5391

[15] Driscoll C, Starik M. The Primordial Stakeholder: Advancing the conceptual consideration of stakeholder status for the natural environment. Journal of Business Ethics. 2004;**49**(1):55-73. DOI: 10.1023/b:busi.0000013852. 62017.0e

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[16] Khan MMH. Role of stakeholders in heritage management in Bangladesh: A case study of Mahasthangarh. CenRaPS Journal of Social Sciences. 2020;**2**(3):354- 372. DOI: 10.46291/cenraps.v2i3.40

[17] UNESCO Operational Guidelines. Operational Guidelines for the Implementation of the World Heritage Convention. Paris: World Heritage Center; 2019

[18] Jahan SH. Communities and microheritage in Bhitargarh, Bangladesh: A case study. In: Coningham R, Lewer N, editors. Archaeology, Cultural Heritage Protection and Community Engagement in South Asia. Singapore: Palgrave Mecmillan; 2019. pp. 17-30. DOI: 10.1007/978-981-13-6237-8. ISBN: 978-981-13-6236-1

### Section 2


**1. Introduction**

Forests contribute greatly to soil conservation and climate change mitigation and represent one of the simplest and most effective means of establishing or maintaining carbon sinks [1]. As one of the most important global carbon reservoirs, tropical forests are home to between half and two-thirds of the Earth's species [2]. Unfortunately, these forest carbon stocks are not stable, given that conversion to other land cover is occurring at an alarming rate despite the increased awareness of climate change [3,4]. Between 2000 and 2005, land-use and land-cover (LULC) changes resulted in forest cover reductions of 0.6% per annum worldwide [5]. Between 2015 and 2020, annual deforestation rates were estimated at 10 million hectares globally [6]. Such land-cover changes occur mainly as a result of anthropogenic disturbances, including deforestation, together with the expansion of croplands and urban areas [7]. LULC changes, mostly caused by agriculture and deforestation, contribute to about one-third of global greenhouse gas (GHG) and worsen the

**Citation:** Kombate, A.; Folega, F.; Atakpama, W.; Dourma, M.; Wala, K.; Goïta, K. Characterization of Land-Cover Changes and Forest-Cover Dynamics in Togo between 1985 and 2020 from Landsat Images Using Google Earth Engine. *Land* **2022**, *11*, 1889. https://doi.org/ 10.3390/land11111889

Academic Editors: Carmine Serio, Guido Masiello and Sara Venafra

Received: 2 September 2022 Accepted: 21 October 2022 Published: 25 October 2022

**Publisher's Note:** MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations.

**Copyright:** © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).

adverse effects of climate change [8,9]. Faced with these increasingly significant effects of climate change, ongoing demands for action are becoming more urgent to curb the extent of deforestation and forest degradation, while enhancing carbon storage through better accounting of carbon sources and sinks. To this end, the United Nations Framework Convention on Climate Change (UNFCCC) has established the REDD+ (Reducing Emissions from Deforestation and forest Degradation Plus) mechanism, which is seen as a global system of centralized forest governance. Aimed primarily at developing nations, REDD+ provides financial compensation for these countries to preserve their forests to reduce carbon emissions and, thus, mitigate the risks of climate change [10,11].

In order to qualify for financial offsets by implementing REDD+, these countries are required to establish National Measurement, Reporting, and Verification (MRV) systems within a national forest monitoring system (NFMS) that must provide national estimates of changes in forest carbon stocks and emissions every two years. The Intergovernmental Panel on Climate Change (IPCC) recommends a combination of Earth observation data and field inventories to estimate forest area, carbon stocks, and changes that follow disturbance [12]. Regular analysis of forest dynamics and LULC changes using satellite data could effectively establish the baseline for the MRV reporting requirement in this context. However, many concerned developing countries are generally faced with a lack of quantitative data on forest degradation-induced changes and limited technical capabilities and material capacity to produce such data for GHG emissions monitoring [12].

The aforementioned challenges beset the West African nation of Togo (République Togolaise), which is the subject of our study, in its quest to meet reporting requirement needs within the framework of the REDD+ strategy, and to guide strategies for monitoring the evolution of forest ecosystems and land cover. A few studies based on observational data have made it possible to monitor changes in land cover in certain parts of the country, but they generally have a starting and an ending year for a period that occasionally spans several decades. The coarse temporal frequency of sampling does not make it possible to detect changes that have been incurred within these periods or to discern which main factors drive their behavior. Furthermore, the spatial extent of these studies is often very limited (i.e., river basins, protected zones, and administrative jurisdictions, among others), whereby changes are not perceived across an entire ecological region or on a national scale. Land and vegetation cover have been studied, but these changes are mainly in protected areas [13–16]. Other studies have focused on watersheds [17,18], while some have been carried out at regional or prefectural scales [19,20]. To a much lesser extent, few comprehensive studies have spanned several ecological zones [21]. These studies have generally covered about 1 to 10% of the national territory, and there are regrettably very few studies quantifying the LULC changes observed over time or analyzing the drivers of these changes.

The spatial and temporal limitations of these previous studies in detecting land-cover changes are related to the difficulties in finding sufficient cloud-free satellite images over large areas. This problem could be overcome by using Synthetic Aperture Radar (SAR) images which, even when acquired in all atmospheric and solar conditions, allow change detection analyses [22], but SAR long historical data does not exist in our study area. These limitations are also related to computational resource problems (large storage capacity and access to high computing power), together with the labor-intensive nature of processing these mega-data [23,24]. Furthermore, global-scale mapping projects often use satellite data with a variable spatial resolution (1 km to 30 m), and generally do not involve local experts; therefore, these approaches do not meet the standards of accuracy that are sought at the national level [25]. With the availability of the new geospatial technology of the Google Earth Engine (GEE), it is now possible to apply very advanced machine-learning algorithms in an efficient manner [26]. The GEE is a cloud-computing platform with a JavaScript code editor that integrates a long-time series of satellite imagery, thereby allowing the classification of large volumes of data and the production of multi-date land-cover changes. It should be further noted that relatively few studies in the scientific literature

have focused on the use of these methods to advance operational forest monitoring in MRV systems [27].

The major challenges to implementing Togo's national REDD+ strategy are reversing the process of forest degradation and savannization, while spatially containing agricultural pressure and constraining urban expansion. These measures should eventually increase carbon stocks and reduce greenhouse gas emissions [28]. Unfortunately, most studies that have been conducted in Togo on progressive LULC changes are incomplete, and forest inventories over the last three decades are very limited. The availability of historical LULC data at a national scale is necessary to meet the challenge of better understanding the LULC dynamics and forest developmental trends over time. This study aims to answer the question of whether the use of multi-temporal images in the GEE would provide a picture of land-cover changes, particularly forest cover, at the national scale. Its main objective is to characterize vegetation dynamics over the entire national territory using a long-time series of Landsat images from 1985 to 2020. More specifically, the study aims to quantify the evolution of spatiotemporal changes and to analyze their effects on forest cover during this period.

### **2. Study Area and Data Used**


**ADVANCES IN NATURAL GAS EMERGING TECHNOLOGIES**

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*2.5. Statistical Analysis*

The descriptive statistics were reported as means ± standard deviation and medians with minimum and maximum values for all variables for each dental-material group. The one-way ANOVA procedure was used to test if there was a difference in total time

and average load among the treatment groups [43]. Post hoc tests were performed using Tukey's adjustment for multiple comparisons. The Games–Howell test was used for multiple comparisons instead of Tukey's test if the assumption of equal variances was not assumed.

The independent-sample Mann–Whitney U test with Bonferroni adjustment was used to compare the medians of the displacement scores of each group with the gold-standard control group. Statistical analyses were performed using IBM SPSS Statistics (Version 25; IBM Corporation 1989, 2018. IBM Corp., Armonk, NY, USA).


**4. Discussion**

The aim of our WRF-SFIRE evaluation was to assess its ability to capture fire-generated emissions in the context of air quality. Hence, we examined the implications of the above results based on their potential applications for wildfire smoke plume rise and dispersion modeling. The following sections discuss model performance and accuracy from the perspective of atmospheric dynamics, as well as address potential implications of uncertainty in fire behavior and the associated input parameters.

#### *4.1. Vertical Plume Rise in the Boundary Layer*

As demonstrated in our results summary in Section 3.2, initially WRF-SFIRE produced a fairly accurate near-source emissions distribution and plume top with a slight under-prediction of concentrations (Figure 5a).

Over time model performance appears to deteriorate. Given that the fire thermal forcing compares relatively well with observations (Section 3.1), a more likely cause for the increasing difference between model and observations is background boundary layer dynamics. The atmosphere was initiated with 10:00 CST sounding, and continually forced with an observations-based constant surface heat flux. However, the cyclic lateral boundary conditions maintained the same vertical wind profile as initially supplied by the sounding at 10:00 CST, irrespective of potentially changing mesoscale conditions in the real atmosphere. Over the course of more than three hours between spin up start and the final minutes of the fire simulation, from which the corkscrew emissions distribution was obtained (Figure 5b), the real atmospheric wind profile likely evolved.

With time and further downwind the effects of any small changes in mesoscale conditions become more pronounced, which is why initially encouraging model performance deteriorated towards the end of the simulation. The markedly narrow band of emissions in Figure 5b suggests that the "corkscrew" location in the LES domain corresponded to the very edge of the plume rather than the center, indicating a shift in mesoscale wind conditions.

Indeed, analysis of observed background 30 m wind direction leading up to and during the burn shows a significant shift to the west, resulting in the LES "corkscrew" profile being extracted from the edge of the plume, rather then the intended center (Figure 6). Accounting for this observed wind

rotation, it is possible to extract a wind-corrected profile, such as shown with a red dotted line in Figure 5b. Assuming an average 20 degree rotation over the course of available wind observations (based on the slope of linear regression shown Figure 6a), the corrected location of the corkscrew maneuver indeed corresponds to the center of the plume (Figure 6b). The wind-corrected profile shown in Figure 5b is a notable improvement from the original non-rotated estimate. Note that this adjustment is extremely crude, as it is based on an estimated wind rotation at one point on a single vertical level and does not take into account potential changes in vertical wind shear.

**Figure 6.** The effects of changing mesoscale wind conditions on plume observations (**a**) Observed change in 30 m wind direction prior to and during the burn. Significant linear trend is shown with a red dashed line. (**b**) Top view of modeled smoke plume during the "corkscrew" maneuver by the instrumented aircraft. Black dot and red star indicate the average location of the "corkscrew" profile from flight with and without wind-correction, respectively.

Unfortunately, unlike the Real-mode WRF simulations, there is no easy way to account for changing lateral boundary conditions in WRF-SFIRE large-eddy mode. Hence, we can expect the ability of the model to accurately capture dispersion to depend strongly on the variability of real background conditions as well as the simulation length and spatial extent of the modeled domain. Namely, an LES will provide better simulations for situations where that actual atmosphere is horizontally uniform and temporally steady. While this presents a limitation for smoke plume rise and dispersion modelers, it is important to consider it in the context of existing alternative sources of field data.

Moreover, unlike instantaneous observational point measurements or overpass-limited derived satellite data, the LES allows us to examine the domain-wide temporal evolution of the plume and identify key features, which are likely to be of interest to dispersion modelers. As shown in Figure 7 and Animation S2, the vertical distribution of emissions in the domain changes throughout the simulation. Following an initial overshoot and a period of active smoke production near the ground, most of the emissions rise and end up near the top of the BL, accumulating just under the inversion level in a wide span of heights. While this vertical distribution may contain modeling and initial condition biases, it is likely to offer dispersion modelers an advantage over the common current approach of using a single empirically derived injection height.

**Figure 7.** Evolution of total column CO2 anomaly.

#### *4.2. Importance of Fire Input Parameters*

As noted in the Introduction, our evaluation work focused on assessing the relationship between coupled surface forcing and the atmosphere in WRF-SFIRE rather than on fire behavior. However, as we attempt to move forward from simple uncoupled burner-type experiments with prescribed constant surface heat flux to more realistic dynamic simulations, we must address the challenges in selecting proper fire input parameters.

Similar to Kochanski et al. [5], we found that the fire behavior model is particularly sensitive to the choice of fuel moisture. This parameter in WRF-SFIRE does not depend on the selected fuel category and was based entirely on measurements in our simulation. We also modified the standard fuel depth and loading parameters associated with Category 1 fuels to match observations, which resulted in very accurate surface heat flux forcing but substantially lower ROS values than observed or those obtained with standard settings.

Notably, similar thermal forcing to the atmosphere can be produced using a range of combinations of fuel categories and parameters in the model. We have not carried out a formal sensitivity analysis as it was beyond our scope and computational abilities, however, future modelers may find the following information helpful. As preliminary tests for our study, we have used Category 1 and Category 3 fuels (short and tall grass) with various combinations of both standard and measurement-based fuel depth and loading parameters to achieve similar surface forcing. The relationships between these parameters are highly non-linear, which makes determining the "correct" choice (in the absence of detailed observational data) difficult. What we found to be encouraging is that while the absolute value of modeled concentrations and ROS changes dramatically depending on the chosen fuel category for a given fire intensity, the relative distribution of emissions does not. The simulated atmosphere is forced solely by the parameterized heat and moisture fluxes, so WRF-SFIRE does not discriminate which combination of fuel characteristics produced a given heat flux that drives the buoyant plume rise.

Given any thermal forcing, the atmospheric response appears to be fairly robust, irrespective of the particular combination of fuel parameters or ROS with which it was achieved. While this study does not aim to establish whether the model sensitivity to fuel conditions is physical, it does suggest that the LES produces realistic plume rise for the given fire intensity.

#### *4.3. ROS and Biases in Modeled Emissions*

The model's poor performance for ROS in our case study likely resulted in reduced simulated emissions concentrations due to lower parameterized fuel consumption rate. This is consistent with the notable negative bias in our modeled CO2 profiles.

As mentioned above, the low ROS values on our simulation are largely a result of our use of non-standard fuel depth and loading parameters. To eliminate alternative causes for slow fire line advance, we compared horizontal winds at the first and second model levels (at ∼8 m and ∼25 m AGL) with data obtained from 2D sonic anemometers mounted at multiple heights of the CSU-MAPS meteorological tower. As shown in Figure 8, the near-surface winds are generally accurately captured by the model. At the lowest vertical level, there tends to be a slight positive bias, which one would expect to contribute to higher rather than lower ROS values.

**Figure 8.** Modeled (red) and observed (black) near-surface horizontal wind.

Apart from their dependency on ROS and fuel consumption, the absolute values of WRF-SFIRE emissions are also controlled by user-prescribed emission factors. In our case study, these factors were not derived from measurements, but were rather based on standard values typical for the Grassland fuel category (see Section 2.2). Hence, the negative bias in our modeled smoke distribution could potentially be reduced, should observations-based emissions factors become available.

#### *4.4. Experimental Design Considerations*

One of the shortcomings of the RxCADRE dataset and this experiment is the substantial (nearly 2.5 h) difference in timing between the sounding balloon launch and the fire ignition. Availability of an additional vertical profile for model evaluation just prior to ignition would have been extremely helpful in mitigating some of the sources of error mentioned in the above sections. A similar recommendation was offered by Kochanski et al. [4], who suggested that an on-site sounding just prior to the burn rather than a few hours earlier would be most useful.

While we recognize the challenges of coordinating balloon launches in the presence of aircraft over the fire, a potential alternative would be to include on-board temperature and wind sensor data from flight with the smoke dispersion measurements.


*<IP_ADDRESS> A pump is introduced: the raised tank is temporarily ignored*

At this stage, it was supposed that the 3.5+ m high tank could be installed either on a roof or on a stand provided with properly constructed ladders for filling and inspections. In rural Africa, once about 20 days, the owner or her/his agent would have to climb up and refill it. At the university however, experimentation in the project required a safer and smarter way of filling the tank. The 'Needs' constraints of Section 3.1.2 specified a 'negligible' energy consumption by operation of the mechanism. Since tank filling would be occasional, a small 12 V DC 4 m peak head pump was acquired. Then for experiments, only one tank ('B' of **Figure 6**) would be necessary. The pump would be used to transfer water from this tank to the mechanism. In addition to being safe, this would conserve water since it could be recycled on daily basis.

### *<IP_ADDRESS> The piston-cylinder part fails: bellows appear: and also fail*

The mechanism was now ready for prototyping. The machine elements and components were assembled. First attempts to run it were made in March 2015. Water leaked past the piston. To properly seal the leakage, it would be necessary to reduce clearances. A new piston with an elastomer O-ring was made. Sealing was achieved but friction was excessive. A lot of pump energy went into overcoming this friction. Then in one re assembly, a forceful push onto the piston burst the cylinder. **Figure 7** shows the broken piece. It was now evident that the engineering necessary to produce an efficient and reliable piston-cylinder assembly would easily 'violate' the 'cost effectiveness' constraint in Section 3.1.2, and probably consume more than 'negligible' energy in operation. The assembly had to be redesigned.

Friction between the cylinder and the piston was the main problem in the assembly. It was therefore decided to eliminate direct contact between the piston and the cylinder. Bellows were introduced. One end of the bellow was fixed to the lower base of the cylinder while the other was fixed to a smaller diameter piston. It was supposed that water would progressively fill the bellow segments starting with the lowest, and in so doing, gradually lift the piston-spring ensemble without any significant friction with the cylinder. The first bellow tried was made from

**79**

**Figure 8.**

*Mechanical Engineering Design: Going over the Analysis-Synthesis Mountain to Seed Creativity*

a 150 mm diameter heli-steel PVC hose. It was readily available and 'reasonably' priced at just below the equivalent of US\$ 5.00 a meter length. It however, failed on trial. When water filled the first segments, they expanded radially before attempting to lift the piston. Even after lift-off, the expansion continued until the steel was beginning to tear out. Attempts were made on using a thicker and stronger rubber bellow made by a local rubber products moulder. It also failed. It was clear that for the bellows to be of use in this project, they would have to be restrained radially which in the circumstances, was not feasible. They were abandoned, but lessons on

need for radial restraint were to serve a breakthrough purpose soon.

*<IP_ADDRESS> The bladder is born: the spring works but it is retired; gravity takes over*

flow regulated hydro mechanism for sun tracking had just been invented.

**3.2 Case 2: design of a herbal oil extractor for small scale industries**

*The prototype bladder: (a) un-protected and (b) when protected.*

This case study is about a project which started off as one of the many group projects in normal class time, intended to overcome the familiar

Bellows failed because they were not restrained radially. Even if they had not failed, it was difficult to tell what would happen to the joints at the base in rural Africa over a prolonged period of intermittent pressurization. It was therefore decided to contain the mechanism water in a flexible liquid sac or bladder that would be completely restrained and protected by a much stiffer, though flexible covering. The active part of the bladder would be an inverted cone frustum grown on a lower normal frustum which in turn, would have grown on a cylindrical portion matching the internal surface and base of the mechanism cylinder. The cylindrical and lower cone frustum would always be with water. Pumping would only affect the upper frustum which would be closed by a permanently joined and sealed piston. The piston would carry a small bleed pipe as shown in **Figure 8**. The primary purpose of this pipe would be to help expel air from the system on first fill. The bladder and its protective covers were constructed and assembled in the mechanism. The system was then test run. At long last, it was able to reach its design peak compression on 2nd July 2015. But the time to reach maximum displacement was in excess of 2 min. Also, towards that endpoint, the 10.8 W pump was drawing maximum current. The top mechanism end cap was removed so that the mechanism could be filled with water against the spring and piston weights only. It took about 20 s to reach the top dead centre position. On opening valve **V2** of **Figure 4** to simulate a day time operation (i.e., rotate the collector East to West), the collector turned the full 180°, but there was difficulty in traversing the mid position. This meant the spring weight (30.2 N) was barely enough to drive the mechanism. However, it had been established that spring force (*kx*) was not necessary to run the mechanism—and therefore the spring could be discarded to give way to gravity weights. A gravity driven, bladder-

*DOI: http://dx.doi.org/10.5772/intechopen.85174*

**Figure 7.** *Example of failure during the project.*

*Mechanical Engineering Design: Going over the Analysis-Synthesis Mountain to Seed Creativity DOI: http://dx.doi.org/10.5772/intechopen.85174*

a 150 mm diameter heli-steel PVC hose. It was readily available and 'reasonably' priced at just below the equivalent of US\$ 5.00 a meter length. It however, failed on trial. When water filled the first segments, they expanded radially before attempting to lift the piston. Even after lift-off, the expansion continued until the steel was beginning to tear out. Attempts were made on using a thicker and stronger rubber bellow made by a local rubber products moulder. It also failed. It was clear that for the bellows to be of use in this project, they would have to be restrained radially which in the circumstances, was not feasible. They were abandoned, but lessons on need for radial restraint were to serve a breakthrough purpose soon.

#### *<IP_ADDRESS> The bladder is born: the spring works but it is retired; gravity takes over*

Bellows failed because they were not restrained radially. Even if they had not failed, it was difficult to tell what would happen to the joints at the base in rural Africa over a prolonged period of intermittent pressurization. It was therefore decided to contain the mechanism water in a flexible liquid sac or bladder that would be completely restrained and protected by a much stiffer, though flexible covering. The active part of the bladder would be an inverted cone frustum grown on a lower normal frustum which in turn, would have grown on a cylindrical portion matching the internal surface and base of the mechanism cylinder. The cylindrical and lower cone frustum would always be with water. Pumping would only affect the upper frustum which would be closed by a permanently joined and sealed piston. The piston would carry a small bleed pipe as shown in **Figure 8**. The primary purpose of this pipe would be to help expel air from the system on first fill.

The bladder and its protective covers were constructed and assembled in the mechanism. The system was then test run. At long last, it was able to reach its design peak compression on 2nd July 2015. But the time to reach maximum displacement was in excess of 2 min. Also, towards that endpoint, the 10.8 W pump was drawing maximum current. The top mechanism end cap was removed so that the mechanism could be filled with water against the spring and piston weights only. It took about 20 s to reach the top dead centre position. On opening valve **V2** of **Figure 4** to simulate a day time operation (i.e., rotate the collector East to West), the collector turned the full 180°, but there was difficulty in traversing the mid position. This meant the spring weight (30.2 N) was barely enough to drive the mechanism. However, it had been established that spring force (*kx*) was not necessary to run the mechanism—and therefore the spring could be discarded to give way to gravity weights. A gravity driven, bladderflow regulated hydro mechanism for sun tracking had just been invented.

#### **3.2 Case 2: design of a herbal oil extractor for small scale industries**

This case study is about a project which started off as one of the many group projects in normal class time, intended to overcome the familiar

**Figure 8.** *The prototype bladder: (a) un-protected and (b) when protected.*

*New Innovations in Engineering Education and Naval Engineering*

cylinder was now changed to vertical as in **Figure 6**.

*<IP_ADDRESS> A pump is introduced: the raised tank is temporarily ignored*

*<IP_ADDRESS> The piston-cylinder part fails: bellows appear: and also fail*

'negligible' energy in operation. The assembly had to be redesigned.

during all phases of rotation of the collector. The latter was considered aesthetically unsound and required more ground space to effect. Therefore, the orientation of the

At this stage, it was supposed that the 3.5+ m high tank could be installed either on a roof or on a stand provided with properly constructed ladders for filling and inspections. In rural Africa, once about 20 days, the owner or her/his agent would have to climb up and refill it. At the university however, experimentation in the project required a safer and smarter way of filling the tank. The 'Needs' constraints of Section 3.1.2 specified a 'negligible' energy consumption by operation of the mechanism. Since tank filling would be occasional, a small 12 V DC 4 m peak head pump was acquired. Then for experiments, only one tank ('B' of **Figure 6**) would be necessary. The pump would be used to transfer water from this tank to the mechanism. In addition to being safe, this would conserve water since it could be recycled

The mechanism was now ready for prototyping. The machine elements and components were assembled. First attempts to run it were made in March 2015. Water leaked past the piston. To properly seal the leakage, it would be necessary to reduce clearances. A new piston with an elastomer O-ring was made. Sealing was achieved but friction was excessive. A lot of pump energy went into overcoming this friction. Then in one re assembly, a forceful push onto the piston burst the cylinder. **Figure 7** shows the broken piece. It was now evident that the engineering necessary to produce an efficient and reliable piston-cylinder assembly would easily 'violate' the 'cost effectiveness' constraint in Section 3.1.2, and probably consume more than

Friction between the cylinder and the piston was the main problem in the assembly. It was therefore decided to eliminate direct contact between the piston and the cylinder. Bellows were introduced. One end of the bellow was fixed to the lower base of the cylinder while the other was fixed to a smaller diameter piston. It was supposed that water would progressively fill the bellow segments starting with the lowest, and in so doing, gradually lift the piston-spring ensemble without any significant friction with the cylinder. The first bellow tried was made from

**78**

**Figure 7.**

on daily basis.

*Example of failure during the project.*

**Figure 9.**

*A home cottage industry 'Two speed' fluids mixer—as designed by MED students left—the assembled unit. Right—the counter-rotating slow speed mechanism (Watch online video at: https://www.youtube.com/watch? v=VymLqK9DDe0).*

'analysis-synthesis' barrier in undergraduate MED. A group of six students had initially been tasked and guided to design and construct a variable temperature and viscosity fluids mixer for a home-cottage cosmetics factory within a period of 6 weeks. The mixer is shown in **Figure 9**. After the project, one of the students was involved in a serious road accident which disabled him, and prevented him from doing the normal pre graduation industrial attachment. To enable him graduate however, he was assigned a new individual design project under supervision of the author at the university. He was to use his experience in the class project, to design (not construct) a herbal oil extractor, again for a home cottage factory. Below is a summary of his design approach.


*Edited by Adel Zaki El-Sonbati*

Composite materials often demand a unique combination of properties, including high thermal and oxidative stability, toughness, solvent resistance and low dielectric constant. This book, "Thermoplastic - Composite Materials", is comprised of seven excellent chapters, written for all specialized scientists and engineers dealing with characterization, thermal, mechanical and technical properties, rheological, morphological and microstructure properties and processing design of composite materials.

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Photo by Stas\_V / iStock

## Thermoplastic Composite Materials

*Edited by Adel Zaki El-Sonbati*

**THERMOPLASTIC**

Edited by **Adel Zaki El-Sonbati**

 **– COMPOSITE MATERIALS**


**3. Conclusions**

Although many reports demonstrated the efficacy and safety of robotic mitral valve repair, there are some specific pitfalls, which surgeons do not encounter in a conventional open heart surgery. In order to achieve a good success of robotic mitral valve repair, surgeons need to understand these particular issues and avoid roboticrelated complications.


*3.1. Numerical Aspects*

The solver, Star-CCM+ version 13.06, employs the finite volume method to model the flow, which uses the integral form of the incompressible RANS equations and divides the computational domain into a finite number of adjoining cells. Continuity and momentum are linked via a predictor–corrector approach. Further details pertaining to the implementation and algorithms used can be accessed in Siemens [28] and Ferziger and Peric [29].

To account for turbulence within the fluid, the *k*–ω model of Wilcox [30] is used. This choice is made following previous work, which showed the particular model to be stable and provide the fastest solution time of all two-equation variants [31]. Benefits of using the *k–*ω model include its seamless application to low *y*+ type meshes (*y*+ < 1). This is a desirable feature, because it avoids the use of wall functions, or any other bifurcations of the solution, as is the case with the *k*–ε model [28]. Although wall functions can predict the forces acting on a body with good accuracy, they may introduce errors in the modelling of hydrodynamic properties in the wake of a ship. For instance, they are unable to account for flow separation [32]. To facilitate a good representation of turbulent properties, a second-order convection scheme is applied throughout all simulations.

To characterise the fluid interphase, the volume of fluid (VoF) method is used [33]. Moreover, Star-CCM+ offers a high-resolution interphase-capturing (HRIC) scheme to enhance the definition of the free surface, which is employed in this study [34]. Vertical ship movements, i.e., sinkage and trim, are not accounted for to reduce the complexity of the simulations. Instead, the ship's position in the x–z plane is adjusted prior to initiating the simulation according to the published results of Elsherbiny et al. [23,35]. This is done in an attempt to reduce the discrepancy between the experimental results and those derived herein. However, some difference is expected to persist since the experimental data, reported by Elsherbiny et al. [23], were determined for a free to sink and trim KCS model.

#### 3.1.1. Computational Domain

As stated previously, frame invariance is not used in this work. Instead, the ship is given the corresponding velocity, which can be consulted in Table 2 for each canal. To model the motion of the ship along the canal, the overset domain approach is used. Thus, the ship is towed in the virtual environment over a static fluid. This has two main consequences. Firstly, the computational domain can no longer conform to the recommendations of the ITTC [36] relating to the positioning and dimensions of the computational boundaries. Instead, an attempt is made to replicate the towing tank used for the experimental work, which is used as a benchmark. Specifically, the towing tank at the Kelvin Hydrodynamics Laboratory at the University of Strathclyde. Naturally, the width and depth of the computational domain must satisfy the test cases (given in Table 2). On the other hand, the length of the computational domain is set as 60 m long. The dimensions are kept the same across case studies (pertaining to the overset domain and the length of the tank). These are shown in Figure 3. The height of the static domain is set as 1.23 ship lengths from the undisturbed water surface in all cases to eliminate any possible effects stemming from the height of the domain.

**Figure 3.** Length of the computational domain and dimensions of the overset domain.

The dimensions of the overset domain, which are maintained identical across case studies, are also shown in Figure 3. It should be noted that for visualisation purposes the figures have been mirrored about the central plane. Other than the boundary, coincidental with the canal and ship centrelines where a symmetry condition is imposed, all other boundaries within the background domain are no-slip walls. This is in line with our goal of designing a more realistic representation of a towing tank. Specifically, so-called 'open boundaries' do not exist in reality [37]. Examples of such boundaries include velocity inlets and pressure outlets. Although it is easier to define the conditions at such boundaries mathematically, they are a definite source of modelling error as discussed earlier.

The manner in which the computational domain is constructed allows the removal of wave damping. Moreover, the definition of turbulent properties on boundaries (such as levels of inlet turbulence) of the fluid is not necessary since there are no inlets nor outlets present. However, it should be noted that the initial conditions in terms of turbulence in the fluid must be specified. In this study, a turbulent viscosity ratio of 0.1% is used, which decays rapidly and is effectively zero in the nondisturbed region of the domain at the end of the acceleration phase, limiting its influence to the early stages of the simulation.


**Preface**

The increasing demands for fine and high value-added chemicals have motivated the long-term exploration of high-performance catalysts with desired activity, selectivity, and durability. Owing to its high natural abundance and low cost, copper as well as its various derivatives has been widely employed as a catalytically active component in a diversity of organic transformations. On the other hand, the multiple accessible oxidation states of reactive Cu element (Cu0, CuI, CuII, and CuIII) within Cu-based catalysts are likely to enable the target catalytic reactions that proceed via both single- and multi-electron transfers. As a result, Cu-based catalysts have also found many applications in redox reactions, such as CO oxidation, selective oxidation of organic compounds, selective catalytic reduction of NOx by CO (CO-SCR), electrochemical hydrogen evolution reaction (HER), and electrochemical CO2 reduction reaction (CO2RR). While a great progress has been made, the prerequisite for successful application of Cu-based catalysts lies in the delicate design and regulation of the local electron structure of active sites. Besides that, the catalytic activity of real Cu-based catalysts can only be predicted to some extent via theoretical modeling and calculations. Therefore, it is still of great significance to continue the exploration of novel and more efficient Cu-based catalysts that deliver an enhanced performance.

This Special Issue, entitled "Synthesis and Applications of Copper-Based Catalysts", provides an overview of recent progress in the synthesis and application of Cu-based materials, with particular emphasis on the latest advanced synthetic approaches, structure modulation strategies, and catalytic performance of copper-based catalysts in heterogeneous and homogeneous catalysis, which can contribute to the development of efficient Cu-based catalysts. We hope that our compilation of such meaningful research studies can provide researchers with new inspiration in this field.

> **Yongjun Ji, Liwen Xing, and Ke Wu** *Editors*