Meet the editors

Prof (Dr) Ashis Kumar Samanta is presently a Professor and Former HOD of the Department of Jute and Fibre Technology, Institute of Jute Technology (IJT), University of Calcutta. He is also the Chairman of the BIS TXD-07 Committee for Speciality Chemicals and Dyestuff as well as the Chairman and Board of Studies/Experts for the Bachelor of Fashion and Apparel Design (BFAD) Course, University of Calcutta. He was the Professor

In-Charge (Academic) at the Institute of Jute Technology (IJT) for 2 years (Aug 2009 to July 2011). He was a member of the Governing Council of IJT for 3 terms, a member of the Research Advisory Committee (RAC) of ICAR-NIRJAFT, Kolkata (2010-2012), a member of the Board of Studies for the B.Des. Course, Viswabharati (2011-13), a member of the PhD Committee in Textile Technology, CU (2009- 2017) and Former Chairman/Convener and Co-Chairman, Textile Engg. Divn. WBSC of IE(I) (1998-2018). He is a member of AASCIT and AATCC, USA. He also served as Former Asst. Director in MANTRA, Surat, 1997-98. He is listed in the global directory of the ISO-TC-38 Committee as expert member from BIS and has attended all plenary meetings of ISO TC 38 since 2015 to present 5 NWIP on the testing of natural dyes. He is the recipient of the "Bharat Nirman Award-2014" for special contributions in the Jute and Textile Technology Education, Research and Training. He received the Eminent Engineer Award in Sept-2019, the "Triguna Charan Sen Award" twice in 1995-96 and & in 2013-14, the "Subject Paper Award" in 2006; and the "Special Merit Award" in 2007 all from the Institution of Engineers (India). He is the reviewer of many international journals such as TRJ, JNF, JIT, JTI, IJFTR and JFP, Coloration Tech, Jclp, J Bio-Res & Tech and Ind. JNF. He is an editorial board member of five reputed national and international textile journals. His main research areas are chemical processing and finishing of textiles including natural dyeing, nano-technology and PCM smart materials, where he has contributed more than 300 publications including 130 research papers (70 international and 60 national) besides 50 technical articles and 101 conference papers, 8 international book chapters and 11 training manuals and 3 books. Presently, he has edited this book on "Chemistry and Technology of Natural and Synthetic Dyes and Pigments". So far, he has guided twelve PhD students in chemical processing of Ttxtiles and is presently guiding another 3 research scholars. He was PI/Project leader of 16 R & D & 2 HRD projects in his career.

Dr. Nasser S. Awwad has a PhD in inorganic and radiochemistry (2000) from Ain Shams University and a post-doctorate degree at Sandia National Labs, New Mexico, USA, 2004. Nasser Awwad was an Associate Professor of radiochemistry in 2006 and Professor of inorganic and radiochemistry in 2011 at the Egyptian Atomic Energy Authority. He has been a Professor at King Khalid University, Abha, KSA from 2011 to now. He has published two

chapters in the following books "Natural Gas - Extraction to End Use" and "Advances in Petrochemicals". He has been the editor for six books about: uranium, new trends in nuclear sciences, dyes in industry and lanthanides, and nuclear power plants. In addition, he has published 84 papers in ISI journals. He supervised 4 PhD and 16 MSc students in the field of radioactive and wastewater treatment. He

participated in 25 international conferences in South Korea, USA, Lebanon, KSA, Egypt and India. He participated in 6 large projects with KACST at KSA and Sandia National Labs at USA on the conditioning of radioactive sealed sources and wastewater treatment. He has been the leader of many research groups about the utilization of nanomaterials for treatment of inorganic and organic pollutants and has also been a member of some research groups. He is a member of the Arab Society of Forensic Sciences and Forensic Medicine and is a member of the Egyptian Society for Nuclear Sciences and its applications. He is on the editorial board of the Journal of Energy and Environmental Research and Technology. He was a member of the organizing committee of the 9th World Congress and Expo on Nanotechnology & Material Science. He was the chairman of a session on Reuse and Recycling of Materials and their products held at India, Kerala, Kottayam 2009. He is a rapporteur of the Permanent Committee for Nuclear and Radiological Protection at King Khalid University and a member of the Committee for the Development of International Cooperation Management at KKU.

Dr. Hamed Majdooa Algarni is the Dean of Scientific Research at King Khalid University (KKU). He received his MSc in physics in 2007 from KKU, Saudi Arabia, and earned his PhD in 2014 from the University of York, the United Kingdom. Dr. Algarni received the Kathleen Mary Stott Prize for excellence in scientific research for the best PhD in 2013 from the University of York, UK. He received an academic distinction award (three times) from the Royal Contents

**Section 1**

**Section 2**

for Their Application on Textiles

*by Ashis Kumar Samanta*

on Textile Substrates *by Virendra Kumar Gupta*

and Its Revival Strategy *by Pubalina Samanta*

of Natural Dyed Textiles *by Anowar Hossain*

*by Deepali Singhee*

**Section 3**

**Preface XI**

Introduction **1**

**Chapter 1 3**

Review on Natural Dyes and Pigments and Its Application **41**

**Chapter 2 43**

**Chapter 3 75**

**Chapter 4 99**

**Chapter 5 123**

Pantone-Like Shade Book with Natural Dyes and Pigments **149**

**Chapter 6 151**

Bio-Dyes, Bio-Mordants and Bio-Finishes: Scientific Analysis

Fundamentals of Natural Dyes and Its Application

Review on Natural Dyes for Textiles from Wastes

Application of Natural Dyes for Herbal Textiles

*by Anupama Mishra and Sapna Gautam*

A Review on Application of Natural Dyes on Textile Fabrics

A Practical Guideline of Few Standardized Ready Made Shades

Embassy of Saudi Arabia, Cultural Bureau, London. He specializes in condensed matter physics, nano-science and nanotechnology, which includes growth, properties, and applications of nanostructured and biomaterials and optoelectronic devices. He has authored and co-authored 90 research articles in highly reputed journals.

## Contents

Preface

Dyeing is an ancient art for textiles and clothing. In ancient times, when no synthetic dyes were available, primitive dyeing using natural dyes was used for dyeing textiles and clothing. With the discovery of the synthetic dye 'Mauve' by W. H. Perkin in 1856 and thereafter on its subsequent commercialization, production and application, synthetic dyes conquered the market for their obvious ready use and lower cost and hence the use of natural colorants declined sharply. However, in recent times, the detrimental effects of some azo-based synthetic dyes (releasing carcinogenic and toxic amines and their hazardous effect on the environment and harmful effect on human skin) have caused a ban of a few such synthetic dyes. Hence, the following three approaches for textile dyeing have started increasing: (i) dyeing and finishing textiles with natural dyes and finishes, (ii) using eco-safe synthetic dyes and chemicals, and (iii) effective effluent

There is limited information available in the form of a consolidated book on natural dyes, pigments, and finishes and production of herbal textiles as well as eco-friendly dyeing chemicals and eco-safe synthetic dyeing and removal of toxic materials and colours from such dyeing effluent etc. Moreover, for more and more commercial exploitation of natural dyes and finishes exploring their functional properties, standardization of natural dyeing techniques need to be adopted for its revival as an alternative to eco-safe synthetic dyeing. Hence, this book was planned and finally published entitled "Chemistry and Technology of Natural and Synthetic Dyes and Pigments" under IntechOpen access publishing

This book includes the following chapters: an introductory editorial chapter on bio-mordants, bio-dyes and bio-finishes; review of natural dyes and pigments and its application, pantone-like shade generation with natural colorants, colour-based natural dyes and pigments, printing with natural dyes and pigments, functional property and functional finishes with natural dyes and pigments, eco-safe synthetic

dyes and chemicals, and miscellaneous review on dyed textiles and clothing

not have seen the light of the day and could not be completed in time.

The academic editor acknowledges the constant support of all the administrative and policy making executives, Author Service Managers and the editorial and production team of IntechOpen publisher without whom this book project could

Both the IntechOpen publisher and the Academic Editor jointly acknowledge all the contributors as authors, whose chapters have been finally accepted after peer

treatment for synthetic dyeing as useful viable option.

including natural dye-based herbal textiles.

review /revision/ modification as required.

media.


**2. Basics of path planning**

#### **2.1 Path planning problems between two points**

The purpose of path planning is to find the best route according to the desired target function between two points. The target function may have different expectations, such as making the route as short as possible or as fast as possible (1). Assuming a two-dimensional plane area and ignoring any kind of disturbing circumstance, ideally shown in **Figure 1** (left) and assuming constant speed, it means in both cases the same path and the same time spent:

$$A \to B \langle s \Rightarrow \min; t \Rightarrow \min \rangle \tag{1}$$

**103**

*Path Planning Optimization with Flexible Remote Sensing Application*

*Path planning options between points of "A and "B" with two different possible routes.*

as shown in **Figure 2**. The quality of the different routes may be the same or different, but it is natural the better road quality allows faster progress, which means that

However, in case of different routes, choice is useless if there is no difference between them according to the target functions. The following options are available

1.The length and the quality of the two paths are the same (s1 = s2; q1 = q2).

2.The length of the two routes is different, but the quality is the same (s1 ≠ s2;

3.The length of the two routes is the same, but the quality is different (s1 = s2;

In general, the last one can be assumed. This gives new more opportunities, so the quality of the longer road can be better or worse than the shorter one and vice versa. In the latter case, when a longer road is combined with a poorer quality, it is clear this is not a choice. In the first case, when the quality of the longer road is

1.The quality of the road is better, but not so much as to compensate the choice

2.The quality of the road is better; however, its quality is able to compensate only

3.The quality of the road is so good that, despite the longer distance, we can

The above is a mere combination of two different routes. It is easy to notice that changing the conditions makes the above more complicated. Example, if we increase the optional routes or the possibility of road quality per each new route but even with changing the quality along one route, the solutions increase exponentially. It is easy to notice that the above assumptions provide an ever-increasing choice, which is in the direction of infinity. However, a large part of the choices can be excluded, so all of those are certainly in a less favorable direction than the one that has already been examined before. As an example, all new routes with the same or worse route quality compared to a route of a given length can be excluded if they

4.The length and quality of the routes are different (s1 ≠ s2; q1 ≠ q2).

better than the shorter one, you can get the following solutions:

for the loss of time resulting from the longer distance.

*DOI: http://dx.doi.org/10.5772/intechopen.86500*

it takes less time to do the same route length.

q1 = q2).

**Figure 2.**

q1 ≠ q2).

with time gains.

achieve time gains.

are longer than the examined one.

for two routes based on their length and quality:

The simplest assumption in reality is very rarely found. In most cases the natural conditions make the simplest approach impossible, which means longer paths as shown in **Figure 1** (right) and longer access times. If the ideal path between the two points is not available, you have to choose from the other options available. The number of available options may vary between zero and infinity, but both lower and upper extremes should be excluded. At the theoretical starting point, the zero option means that there is no point in the task, and with the infinite possibility, we can only count on the theory. By excluding the two extremes, we find that the number of solutions varies from 1 to a large number. The only possible path, of course, does not give a choice. The first choice appears in case of two different paths

**Figure 1.**

*Path planning between points of "A" and "B" in ideal (left) and in natural (right) circumstances with only one option.*

*Path Planning Optimization with Flexible Remote Sensing Application DOI: http://dx.doi.org/10.5772/intechopen.86500*

*Path Planning for Autonomous Vehicles - Ensuring Reliable Driverless Navigation...*

victims in case of disaster.

called as an ideal case.

**2. Basics of path planning**

observed field can be wider and wider when passing the route. Following this logic, we can conclude that choosing a route is not merely premised on getting from one point to another one but rather on supervising and monitoring an area of responsibility. The purpose of the area monitoring is typical for safety reason, prevention and protection against criminals, swift forest fire detection, or offering first aid to

Following the path or monitoring, the area can be done by the traditional way meaning that the trained staff uses a vehicle; conversely it can be done in advanced way meaning that the presence of staff on board of the vehicle is no longer required. The latter can be interpreted as using the autonomous system. One of the advantages of autonomous systems is that we can eliminate human error by applying it. The effectiveness of the autonomous system should be examined under different conditions. For easier understanding, the best method is if we start with the simplest condition that means the least distracting circumstances. This can also be

The purpose of observing an area is to detect the unrequired event or incident as soon as possible. In general, the faster the autonomous system detects the event, the more effective it is to apply. We need to look at how to optimize the path planning of

The purpose of path planning is to find the best route according to the desired

*A* → *B*(*s* ⇒ min;*t* ⇒ min) (1)

*Path planning between points of "A" and "B" in ideal (left) and in natural (right) circumstances with only one*

The simplest assumption in reality is very rarely found. In most cases the natural conditions make the simplest approach impossible, which means longer paths as shown in **Figure 1** (right) and longer access times. If the ideal path between the two points is not available, you have to choose from the other options available. The number of available options may vary between zero and infinity, but both lower and upper extremes should be excluded. At the theoretical starting point, the zero option means that there is no point in the task, and with the infinite possibility, we can only count on the theory. By excluding the two extremes, we find that the number of solutions varies from 1 to a large number. The only possible path, of course, does not give a choice. The first choice appears in case of two different paths

target function between two points. The target function may have different expectations, such as making the route as short as possible or as fast as possible (1). Assuming a two-dimensional plane area and ignoring any kind of disturbing circumstance, ideally shown in **Figure 1** (left) and assuming constant speed, it

the autonomous system with flexible remote sensing methods.

means in both cases the same path and the same time spent:

**2.1 Path planning problems between two points**

**102**

**Figure 1.**

*option.*

**Figure 2.** *Path planning options between points of "A and "B" with two different possible routes.*

as shown in **Figure 2**. The quality of the different routes may be the same or different, but it is natural the better road quality allows faster progress, which means that it takes less time to do the same route length.

However, in case of different routes, choice is useless if there is no difference between them according to the target functions. The following options are available for two routes based on their length and quality:

In general, the last one can be assumed. This gives new more opportunities, so the quality of the longer road can be better or worse than the shorter one and vice versa. In the latter case, when a longer road is combined with a poorer quality, it is clear this is not a choice. In the first case, when the quality of the longer road is better than the shorter one, you can get the following solutions:

The above is a mere combination of two different routes. It is easy to notice that changing the conditions makes the above more complicated. Example, if we increase the optional routes or the possibility of road quality per each new route but even with changing the quality along one route, the solutions increase exponentially. It is easy to notice that the above assumptions provide an ever-increasing choice, which is in the direction of infinity. However, a large part of the choices can be excluded, so all of those are certainly in a less favorable direction than the one that has already been examined before. As an example, all new routes with the same or worse route quality compared to a route of a given length can be excluded if they are longer than the examined one.

**Figure 3.**

*An example for path planning between points of "A" and "B" in case of more options with pathway and with intermediate points.*

Based on the above, it can be observed that in natural conditions there can be a significant number of solutions even between two points.

#### **2.2 Path planning problems between several points**

If we assume more than two points to be touched in the course of the route, we find that the number of options increases dramatically again as shown in **Figure 3**. Optimizing a multipoint path planning in a given plane area raises the travelling salesman problem (TSP) that has already been examined by many studies. At elementary level this question is raised hundreds years ago together with the trade development; however, as a classic scientific problem, it was mentioned firstly by Held and Karp [7] and Bellman [8]. They used dynamic programming approaches to find the solution.

Later other researchers followed these methods [9, 10], and others developed new ones offering other algorithms as well as time-dependent TSP [11] or TSP with time window and precedence constraints [12].

As new technologies appear in autonomous systems, like unmanned aerial vehicles (UAV) or drone applications, researchers found new problems and tried to give new approaches finding the best or optimized solution. Some of these studies focus only on the drone applications; others tried to combine drone application with the traditional delivery system [13, 14]. In these studies authors used different examining methods, as well as exact methods [15], heuristic methods [16–18], or approximation algorithm [14]. Bouman et al. cites a detailed summary about the above researches and results [19].

Based on the above, TSP is a very complex therefore not just natural condition, but also some idealistic assumption can generate a significant number of solutions.


**1. Introduction**

Coumarin heterocycle is an award gifted from nature, coumarins get the name from "Coumarou" which is the vulgarity term of the plant that belongs to the Fabaceae family named tonka bean. The natural product of coumarin and its scaffolds were isolated and purified by Vogel in 1820 [1], and it was prepared by Perkin in 1868 [2]. The lactones-based ubiquitous heterocyclic coumarins have been known as fragrance products in perfumes, because of their nature of sweet smell. Naturally appearing coumarins and their analogs are known in about 700 chemical

structures in more than 100 plant families [3] and remarkably, the number of core structures of coumarin derivatives still increases. Coumarins (2*H*-1-benzopyran-2 one) are one the most important heterocyclic compounds and their scaffolds are an essential class of lactone family with a fused α-pyrone ring attached to a benzene moiety. The centre core of coumarins has shown great interest over the years because of their significant biological importance and applications [4–14]. This type of fused oxygen heterocycles is associated with a wide range of biological properties like antitubercular, anti-inflammatory, anticancer, anticonvulsant, and neuroprotective, such as antiviral, antifungal, antibacterial, antihyperglycemic, anticoagulant, antihypertensive, antiadipogenic, anti-HIV, antibacterial, antimicrobial and antioxidant, etc. effects.

Moreover, coumarins analogs are attracting the vital attention of chemists due to their broad range of materials applications like photosensitizers, fluorescent, optical brighteners [15, 16], and laser dyes [17, 18], and additives [19] in food, cosmetics, and pharmaceuticals, etc.

In this particular lactone based coumarin family of drug molecules such as warfarin [20], acenocoumarol [21], and phenprocoumon [22] are the most prominent ones, which are currently used in a many different nations (**Figure 1**). Due to their unique nature and greater half-life, notably, warfarin is used more often compare to acenocoumarol. These results highlight a significant new development in the biological evaluation of coumarins and their derivatives, as well as medicinal chemistry [23–30]. As a current result, the

**Figure 1.** *Representative examples of lactone-based bioactive coumarin-based derivatives.*


*Article* **Novel Biodegradable Poly (Lactic Acid)/Wood Leachate Composites: Investigation of Antibacterial, Mechanical, Morphological, and Thermal Properties**

**Mohammad Hassan Shahavi 1,\* , Peyman Pouresmaeel Selakjani 1 , Mohadese Niksefat Abatari 1 , Petar Antov 2,\* and Viktor Savov 2**

**Abstract:** This research aimed to investigate the effects of using wood leachate (WL) powder as a cost-effective filler added to novel poly (lactic acid) biocomposites and evaluate their mechanical, thermal, morphological, and antibacterial properties. Fourier transform infrared spectroscopy (FTIR), tensile test, Charpy impact test, Shore hardness, scanning electron microscope (SEM), differential scanning calorimetry (DSC), contact angle, and bacterial growth inhibition tests were employed to characterize the developed biocomposites. The SEM results indicated a proper filler dispersion in the polymer matrix. WL powder improved the hydrophobic nature in the adjusted sample's contact angle experiment. Markedly, the results showed that the addition of WL filler improved the mechanical properties of the fabricated biocomposites. The thermal analysis determined the development in crystallization behavior and a decline in glass transition temperature (Tg) from 60.1 to 49.3 ◦C in 7% PLA-WL biocomposites. The PLA-WL biocomposites exhibited an antibacterial activity according to the inhibition zone for *Escherichia coli* bacteria. The developed novel PLA-WL composites can be effectively utilized in various value-added industrial applications as a sustainable and functional biopolymer material.

**Keywords:** antibacterial; biocomposite; biopolymers; mechanical properties; poly (lactic acid); wood leachate

## **1. Introduction**

In recent years, the enhanced environmental awareness, the increased need for sustainable and "green" materials, as well as the stringent legislative regulations related to waste management and cascading use of natural resources have forced many researchers to develop novel biodegradable polymers as a viable alternative to conventional polymers [1–5]. Despite the numerous advantages of biocomposites such as the potential to create a sustainable industry as well as enhancement in various properties such as durability, flexibility, high gloss, clarity, and tensile strength, there are certain drawbacks, such as deteriorated physical and mechanical properties, poor interface adhesion, brittleness, lower thermal resistance and water absorption, susceptibility to fungi and insect attacks, etc., limiting their wider application as functional materials [6–9]. Poly (lactic acid) (PLA) is one of the most suitable biodegradable polymers widely employed in many applications ranging from the biomedical field, e.g., in engineered drug delivery systems [10,11], tissue engineering (scaffolds) [12,13], and wound dressing [14,15] to food packaging and disposable plastic bags [16–18] due to its versatility, excellent processability, and biocompatibility. It is also widely used as a 3D printing feedstock for desktop fused filament fabrication 3D printers [19]. PLA is a biodegradable aliphatic semicrystalline polyester synthesized from lactic acid monomer (LA; 2-hydroxypropanoic acid), which is soluble in water and

**Citation:** Shahavi, M.H.; Selakjani, P.P.; Abatari, M.N.; Antov, P.; Savov, V. Novel Biodegradable Poly (Lactic Acid)/Wood Leachate Composites: Investigation of Antibacterial, Mechanical, Morphological, and Thermal Properties. *Polymers* **2022**, *14*, 1227. https://doi.org/10.3390/ polym14061227

Academic Editor: Gianluca Tondi

Received: 23 February 2022 Accepted: 15 March 2022 Published: 18 March 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/).

occurs in two enantiomeric forms, i.e., l-(+)-LA and d-(−)-LA. PLA represents a sustainable alternative to fossil-derived products, since it is derived from the fermentation of renewable agricultural biomass resources rich in carbohydrates, such as corn starch and sugar beets. Filler materials have been widely used in the polymer industries for economic reasons. Furthermore, it was reported that the fillers could also improve biocomposites' mechanical and thermal properties [20–24]. Lignocellulosic waste and residues are among the most widely used fillers in polymeric composites. Using these natural materials will produce lighter products and lower the environmental footprint due to their biodegradability and lower cost. Another important benefit of using natural waste and by-products is significantly improving polymers' mechanical properties [25–27]. resources rich in carbohydrates, such as corn starch and sugar beets. Filler materials have been widely used in the polymer industries for economic reasons. Furthermore, it was reported that the fillers could also improve biocomposites' mechanical and thermal properties [20–24]. Lignocellulosic waste and residues are among the most widely used fillers in polymeric composites. Using these natural materials will produce lighter products and lower the environmental footprint due to their biodegradability and lower cost. Another important benefit of using natural waste and by‐products is significantly improving polymers' mechanical properties [25–27]. As in any wood‐based industry, the medium‐density fiberboard (MDF) production

aliphatic semicrystalline polyester synthesized from lactic acid monomer (LA; 2‐ hydroxypropanoic acid), which is soluble in water and occurs in two enantiomeric forms, i.e., l‐(+)‐LA and d‐(−)‐LA. PLA represents a sustainable alternative to fossil‐derived products, since it is derived from the fermentation of renewable agricultural biomass

As in any wood-based industry, the medium-density fiberboard (MDF) production factories usually use wood as their feedstock [28]. In the process of MDF production and after wood chipping, the chips are washed with high-pressure steam. The waste produced by this process is a dark brown liquid called leachate. The wood leachate (WL) has a complex composition, but as mentioned in the literature, the leachate compounds are mostly phenol, tannins, lignin, and volatile fatty acids [29–31]. The structure of the main components present in the WL is shown in Figure 1. factories usually use wood as their feedstock [28]. In the process of MDF production and after wood chipping, the chips are washed with high‐pressure steam. The waste produced by this process is a dark brown liquid called leachate. The wood leachate (WL) has a complex composition, but as mentioned in the literature, the leachate compounds are mostly phenol, tannins, lignin, and volatile fatty acids [29–31]. The structure of the main components present in the WL is shown in Figure 1.

*Polymers* **2022**, *14*, x FOR PEER REVIEW 2 of 14

**Figure 1.** Structure of the main components of the wood leachate (WL) (**a**) phenol, and (**b**) lignin. **Figure 1.** Structure of the main components of the wood leachate (WL) (**a**) phenol, and (**b**) lignin.

The wood‐based composite industry has developed rapidly during the last few decades, and its continued development is expected, e.g., the global demand for wood‐ based materials is projected to increase threefold between 2010 and 2050. In 2019, the annual global production of wood‐based composites was estimated to be 357 million m3 [2]. This generates a massive amount of organic waste, i.e., from acid waste to aromatic leachates. In recent years, due to the increasing global environmental awareness, the need to decrease dependence on petroleum‐based products, and new environmental regulations, great attention has been paid to the possibilities of developing biodegradable polymers from renewable, bio‐based agricultural waste and residues [32–34]. Considering the great amounts of WL discharged by the wood‐based industries, it is feasible to develop new methods for its efficient recycling and reuse in value‐added applications. In addition, reusing WL waste solves waste management issues and has remarkable economic and environmental benefits. This acidic waste material could harm the environment and thus needs to be treated before discharge. Leachates may contain large quantities of organic pollutants such as ammonia (NH3), heavy metals, mineral salts, and phenol derivatives. Moreover, previous work has shown that this leachate can infiltrate and pollute the soil and the surrounding water, creating an environmental problem that needs to be addressed [35–38]. The WL's main components, i.e., lignin, phenol, and tannin, can be The wood-based composite industry has developed rapidly during the last few decades, and its continued development is expected, e.g., the global demand for woodbased materials is projected to increase threefold between 2010 and 2050. In 2019, the annual global production of wood-based composites was estimated to be 357 million m3 [2]. This generates a massive amount of organic waste, i.e., from acid waste to aromatic leachates. In recent years, due to the increasing global environmental awareness, the need to decrease dependence on petroleum-based products, and new environmental regulations, great attention has been paid to the possibilities of developing biodegradable polymers from renewable, bio-based agricultural waste and residues [32–34]. Considering the great amounts of WL discharged by the wood-based industries, it is feasible to develop new methods for its efficient recycling and reuse in value-added applications. In addition, reusing WL waste solves waste management issues and has remarkable economic and environmental benefits. This acidic waste material could harm the environment and thus needs to be treated before discharge. Leachates may contain large quantities of organic pollutants such as ammonia (NH3), heavy metals, mineral salts, and phenol derivatives. Moreover, previous work has shown that this leachate can infiltrate and pollute the soil and the surrounding water, creating an environmental problem that needs to be addressed [35–38]. The WL's main components, i.e., lignin, phenol, and tannin, can be used as a natural filler in polymer composites. The lignin in the WL could play a strong bioadhesive role in the polymeric blends, and the phenol and tannin could prevent bacterial growth on the composite surface [39,40].

used as a natural filler in polymer composites. The lignin in the WL could play a strong

This research aimed to evaluate the feasibility of using WL powder as an additive in PLA-based biocomposites and evaluate their exploitation properties. The chemical structure of the fabricated composites was characterized using Fourier transform infrared spectroscopy (FTIR). The effects of WL incorporation on the mechanical, thermal, and morphological properties of the PLA matrix were investigated using tensile tests, differential scanning calorimetry (DSC), and field emission-scanning electron microscopy (FE-SEM). Furthermore, the inhibition zone examination was used to detect the antimicrobial behavior of the developed PLA-WL biocomposites using *Escherichia coli (E. coli)* as the model microbe.

#### **2. Materials and Methods**

#### *2.1. Materials*

The PLA (CAS No: 26100-51-6) with a molecular weight of 80,000 g/mol, a specific gravity of 1.24 g/cm3 , and a melting point of 155–170 ◦C was purchased from BIOKAS Ö5 (Chemiekas GmbH, Vienna, Austria). The raw WL (with 3% solids content) and fibers used in this work were supplied by the Arian Maryam Incorporation factory (AMI, Rasht, Iran) from the Arian Saeed Industrial Group. The lignin weight percentage of dry WL was determined as the acid-insoluble Klason lignin. The standard approach for determining lignin content is based on Klason's method of hydrolysis of materials using 72% sulfuric acid (Merck 1.00748 98% diluted). Lignin is the substance remaining after hydrolysis in this step, and it is the insoluble residual extracted by filtration and measured by the gravimetric procedure [41,42]. The lignin content of dried WL was determined to be about 22%.

### *2.2. Biocomposite Preparation*

To prepare the novel biocomposites, WL was vacuum dried at 100 ◦C in a vacuum oven (Memmert® GmbH & Co. KG, Schwabach, Germany) at the first step. Then, the obtained solid material was grounded in powder using a lab-scale mill. The PLA was also vacuum dried at 70 ◦C to evaporate the moisture content. WL powder was dry blended with PLA and then melted compounded in an internal mixer (Brabender® GmbH & Co. KG, Duisburg, Germany) at 180 ◦C for 15 min with the screw rotor speed of 50 rpm. The manufacturing parameters of the laboratory-fabricated PLA-WL biocomposites are given in Table 1. The prepared biocomposite blends were placed into a mold of 2 mm height, and the sheets were fabricated by a hot-pressing process in a laboratory press of 5 tons. The press temperature applied was 180 ◦C. The pressure value used was 1.4 MPa for 5 min [43].

**Table 1.** Manufacturing parameters of PLA-WL biocomposites produced in this work.

#### *2.3. Characterization*

2.3.1. Structural and Thermal Analysis

FTIR spectroscopy was employed to identify the composites' functional groups. A Bruker Equinox 55LS 101 series instrument (Bruker, Karlsruhe, Germany) with a resolution of 4 cm−1 (50 scans on average) was used for this purpose. The Netzsch DSC Maia 200 F3 facilitated with a low-temperature accessory was employed for performing the DSC analysis. It was performed at a 20 ◦C/min heating rate at temperatures ranging from −20 to 280 ◦C through a nitrogen atmosphere. The stepwise specific heat increment midpoint was taken as the glass transition temperature (Tg). All DSC adjustments were made according to ASTM D3418 [44].

#### 2.3.2. Mechanical and Morphological Investigation

The tensile stress–strain experiments were accomplished using a Gotech Universal testing machine AI-7000-LA (Gotech Testing Machines, Inc., Taichung, Taiwan), following the ASTM D638 [45]. The examinations were carried out at room temperature (25 ◦C). The experiments were carried out at a 5 mm/min cross-head speed. At least five test specimens of any composition were considered for tensile tests. The ASTM D256 [46] standard was followed to perform the Charpy impact strength measurement of the developed composites. The notched test specimens (80 × 10 × 3.8 mm3 ) were tested using FRANK Baldwin-Model-BLI pendulum impact testing equipment (Frank Bacon, Warren, MI, USA). A 45 V-shaped notch was made in the center of the impact sample by razor notching equipment (CEAST). The notch tip radius was 0.25 mm, and the specimen depth remaining under the notch was 10.17 mm. For each composition, at least five samples were examined. Shore A sample hardness was measured using FRANK measuring instruments with ASTM D2240 [47]. Philips (Philips-X130) SEM equipment was employed for identifying the fracture surface of the prepared composite sheets in liquid N2. The SEM micrographs of the surface were obtained using the cold field emission mode on the surface of samples [48–51].

#### 2.3.3. Surface Hydrophobicity and Antibacterial Activity

The hydrophobicity of the laboratory-fabricated biocomposites was measured using a Kruss G10 contact angle measurement system (KRÜSS GmbH, Hamburg, Germany). The contact angle of the distilled water droplets was calculated on the composite surface [52].

The antimicrobial behavior of the developed composite materials was analyzed using *E. coli* bacteria. The *E. coli* bacteria was inserted into a liquid broth and cultivated under stirring of 120 rpm for 10 h at 37 ◦C in a shaking incubator. The resulting sample was diluted to around 100 (CFU)/mL using the broth media, and then, the diluted mixture was added to the agar medium. The PLA and PLA-WL samples were sterilized by autoclaving and placed on the plates with the agar's surface in the tangent state and were incubated for 24 h at 37 ◦C. A comparative analysis of the biocomposites' antimicrobial behavior measured the bacterial growth inhibition region (µm) [53,54].

#### **3. Results and Discussion**

#### *3.1. Structural Characterization*

The FTIR absorption peaks of the pure PLA and the PLA-WL biocomposites are shown in Figure 2. The C=O stretching absorption peaks related to PLA or ester groups were detected at 1750 cm−1 . The C–O bonds in the PLA structure were visible at 1182 cm−1 . The peak at 1363 cm−1 was related to PLA methyl groups and C–H bonds vibration. The C–C bonds stretching peak of the PLA chemical structure appeared at 836 cm−1 .

After incorporating WL to the PLA matrix, the band near 1490 cm−1 was attributed to vibration of the phenolic rings, and the peaks at 1450, 1210, 1188 cm−1 for phenolic ring or phenolic hydroxyl groups vibrations [55,56] appeared in the spectrums of PLA-WL. That is proved by the WL's phenolic structures (i.e., lignin, tannins, and phenol). The only difference between PLA-WL peaks are in their intensity that is related to the amount of filler and its compounds within the sample.

#### *3.2. Mechanical Properties*

The results obtained for the mechanical properties of the laboratory-made PLA-WL biocomposites, i.e., tensile strength, break elongation, and elastic modulus, are presented in Table 2.

**Figure 2.** FTIR spectra of PLA and PLA‐WL biocomposites. **Figure 2.** FTIR spectra of PLA and PLA-WL biocomposites.

*3.2. Mechanical Properties* **Table 2.** The mechanical characteristics of the fabricated PLA-WL biocomposites.

**Strength (MPa) Break (%) (MPa) Strength (KJ/m2) Hardness** PLA 33.95 4.00 1837 38.62 89.21 PLA‐WL‐3 58.65 8.80 1553 46.21 91.32 PLA‐WL‐5 121.75 16.73 1817 62.47 91.85 PLA‐WL‐7 169.75 18.93 1942 74.56 92.30 PLA‐WL‐9 66.95 11.71 1427 61.84 86.21 A graphical representation of the stress–strain curves of the developed PLA‐WL biocomposites with different addition levels of WL as a filler is shown in Figure 3. Data are in correspondence to previously reported specifications for high molecular weight PLA [57]. The tensile strength of the PLA‐WL blends was slightly increased by the filler A graphical representation of the stress–strain curves of the developed PLA-WL biocomposites with different addition levels of WL as a filler is shown in Figure 3. Data are in correspondence to previously reported specifications for high molecular weight PLA [57]. The tensile strength of the PLA-WL blends was slightly increased by the filler loading increment (WL powder). The tensile strength was increased by about 400% at PLA-WL-7, which has a 7% concentration of the WL powder in its structure. The higher tensile strength of the filler-induced samples indicated the effect of lignin in the WL structure. The lignin has a paste-like impact within the polymer matrix that causes higher tensile strength values [58]. Lignin penetrates into the gaps of adjacent particles and intramolecular space of the PLA, and it improves the interfacial adhesion between WL filler and PLA matrix (physical adhesion) [59].

loading increment (WL powder). The tensile strength was increased by about 400% at PLA‐WL‐7, which has a 7% concentration of the WL powder in its structure. The higher tensile strength of the filler‐induced samples indicated the effect of lignin in the WL structure. The lignin has a paste‐like impact within the polymer matrix that causes higher tensile strength values [58]. Lignin penetrates into the gaps of adjacent particles and intramolecular space of the PLA, and it improves the interfacial adhesion between WL filler and PLA matrix (physical adhesion) [59]. Markedly, the elongation at break was also increased in higher WL filler‐loaded samples. This might be attributed to the plasticization effect of the lignin. Plasticization is described as the action of plasticizers on the matrix structure of materials, causing it to swell. Plasticizers reduce the Tg and melt viscosity by increasing the free volume by Markedly, the elongation at break was also increased in higher WL filler-loaded samples. This might be attributed to the plasticization effect of the lignin. Plasticization is described as the action of plasticizers on the matrix structure of materials, causing it to swell. Plasticizers reduce the Tg and melt viscosity by increasing the free volume by spacing polymer chains and increasing the mobility of chain segments. Lignin's plasticization effect will also help to improve polymer matrix mobility via the effects of OH groups presents on lignin structure, which interacts with the polymer structure and leads to higher mobility as well as the processability and toughness of the resulting composite [60]. It was reported that high filler content increased the agglomeration probability [61], and the regions with stress concentration that requires less energy to crack will exist in this regard. The findings showed a significant decrease in tensile strength at 9% WL powder content. The localization

spacing polymer chains and increasing the mobility of chain segments. Lignin's

of WL agglomerates between the PLA polymer chains in PLA-WL-9 resulted in decreased biocomposite break elongation. The steric hindrance of lignin, phenol, and tannin bonds in high WL powder concentrations leads to lower lock energy between the PLA chains.

The elastic modulus of the PLA-WL-3 specimen indicated a drop following WL's addition due to lignin's plasticization effect, referring to Table 2. The lignin mechanically bound the PLA chains in higher WL volumes, and the lignin's paste activity exceeded its plasticization impact. Lignin could fit the polymer matrix, causing less mobility than the samples without or with a fewer percentage of WL powder filler [62].

During force loading in the testing machine, partial spaces were made, which barricaded the stress dissemination between the matrix and the filler. The degree of locking increased as the filler loading increased, raising the elastic modulus and stiffness. At the PLA-WL-9 sample, a sudden drop was observed related to the agglomeration of filler materials. The data relating to the Charpy impact strength of the fabricated films are presented in Table 2. The Charpy impact strength of the biocomposites was enhanced by the increment of the filler content from the results. Regular energy transfer in the matrix is substantial for impact persistence [63]. The highest impact resistant composition in this study was the PLA-WL-7 sample with an impact strength of 74.56 KJ/m2 , and the factor has a growing trend by the addition of filler up to this composition. In dispersed phases addition into a polymer matrix, the dispersed phase's good dispersion, filler particle sizes, and proper interfacial incorporation are the most critical factors determining the materials' optimum performance. The blend's impact strength drop with 9% WL powder was due to some unfavorable filler dispersion in the polymer matrix. *Polymers* **2022**, *14*, x FOR PEER REVIEW 7 of 14

**Figure 3.** Stress–strain curves of tensile tests for neat PLA and PLA‐WL biocomposites. **Figure 3.** Stress–strain curves of tensile tests for neat PLA and PLA-WL biocomposites.

*3.3. Thermal Behavior* The DSC analysis was employed to investigate the effect of various filler (WL powder) loadings on the thermal characteristics of the developed PLA‐WL biocomposites. Understanding the polymers' crystallization behavior under dynamic conditions is considerable because most processing procedures perform in non‐isothermal conditions [64,65]. Figure 4 illustrates the crystallization exotherms of the PLA‐WL biocomposites. The parameters of the DSC curves for crystallization exotherms, such as the crystallization peak (Tc), glass transition temperature (Tg), and the crystallization enthalpy (dHc), were calculated from the under peak surface area. The composite's hardness results are shown in Table 2. The hardness of the blended sheets increased with the higher filler content. It may be due to the WL powder dispersion and void minimization into the PLA matrix and intense physical engagement between the WL and PLA chains. However, the hardness increment value by filler addition has a slight trend, which is caused by dispersion of the WL within the structure and not just on the surface of the developed biocomposites. The highest hardness value of 92.3 was determined for the PLA-WL-7 sample. It can also be deduced that the filler increased the hardness of polymeric materials by filling the empty micro gaps between the polymer frameworks. Overall, the mechanical properties showed that 3–7% content of WL powder

The WL had a positive effect on the crystallization behavior of the PLA as the crystallization peak temperature was shifted to higher values after incorporating the WL

Subsequently, the glass transition temperature was lowered by incorporating WL powder into the composite structure. The PLA had a Tg drop at 60.1 °C, and it is evident that WL lowers Tg as it makes the chains more mobile during the matrix due to its plasticization effect. According to the DSC results, the Tg has a positive trend by increasing the WL content in the laboratory‐made biocomposites. This might be attributed to the chain locks occurring by increasing the filler amount. Lignin could hinder the polymer chains' movement, resulting in greater Tg in higher WL filler ratios. Conversely, lignin could enhance the PLA chains mobility due to its plasticization effect, facilitating

PLA‐WL‐7 led to a high mechanically strengthened material [66,67], which complies with the results from mechanical testing. The plasticization effect of lignin leads to the free movement of the PLA chains, and as a result, the crystallinity of the modified composites became higher than that of neat PLA. On the other hand, high amounts of lignin and other phenolic compounds (in PLA‐WL‐9) present in the WL composition significantly reduced the polymer chains mobility caused by the steric hindrance impact associated with their

crystallization growth and improving crystallinity.

aromatic composition.

could be applied as filling material, leading to amelioration in the PLA composite's mechanical properties, such as tensile strength, impact strength, and hardness. In addition, the induction of lignin, tannin, and phenol in low concentrations to the polymer blend can make it widely applicable in different industries according to the antibacterial effects of these materials, which are explained in the following section.

#### *3.3. Thermal Behavior*

The DSC analysis was employed to investigate the effect of various filler (WL powder) loadings on the thermal characteristics of the developed PLA-WL biocomposites. Understanding the polymers' crystallization behavior under dynamic conditions is considerable because most processing procedures perform in non-isothermal conditions [64,65]. Figure 4 illustrates the crystallization exotherms of the PLA-WL biocomposites. The parameters of the DSC curves for crystallization exotherms, such as the crystallization peak (Tc), glass transition temperature (Tg), and the crystallization enthalpy (dHc), were calculated from the under peak surface area. *Polymers* **2022**, *14*, x FOR PEER REVIEW 8 of 14

**Figure 4.** The DSC curves for PLA‐WL biocomposites. **Figure 4.** The DSC curves for PLA-WL biocomposites.

*3.4. Morphology* The SEM technique was used to identify the biocomposites' morphological modifications on the surface and cross‐sections split in liquid N2. A graphical representation of the samples' SEM images (PLA, PLA‐WL‐7, and PLA‐WL‐9 biocomposites) is presented in Figure 5. The WL had a positive effect on the crystallization behavior of the PLA as the crystallization peak temperature was shifted to higher values after incorporating the WL filler. As expected, it also induced the crystallization enthalpy. The highest crystallization degree was determined for the PLA-WL sample. The higher crystalline structure of the PLA-WL-7 led to a high mechanically strengthened material [66,67], which complies with the results from mechanical testing. The plasticization effect of lignin leads to the free movement of the PLA chains, and as a result, the crystallinity of the modified composites became higher than that of neat PLA. On the other hand, high amounts of lignin and other phenolic compounds (in PLA-WL-9) present in the WL composition significantly reduced the polymer chains mobility caused by the steric hindrance impact associated with their aromatic composition.

Subsequently, the glass transition temperature was lowered by incorporating WL powder into the composite structure. The PLA had a Tg drop at 60.1 ◦C, and it is evident that WL lowers Tg as it makes the chains more mobile during the matrix due to its plasticization

(**a**) (**b**)

(**c**) (**d**)

effect. According to the DSC results, the Tg has a positive trend by increasing the WL content in the laboratory-made biocomposites. This might be attributed to the chain locks occurring by increasing the filler amount. Lignin could hinder the polymer chains' movement, resulting in greater Tg in higher WL filler ratios. Conversely, lignin could enhance the PLA chains mobility due to its plasticization effect, facilitating crystallization growth and improving crystallinity. **Figure 4.** The DSC curves for PLA‐WL biocomposites.

*Polymers* **2022**, *14*, x FOR PEER REVIEW 8 of 14

#### *3.4. Morphology 3.4. Morphology* The SEM technique was used to identify the biocomposites' morphological

The SEM technique was used to identify the biocomposites' morphological modifications on the surface and cross-sections split in liquid N2. A graphical representation of the samples' SEM images (PLA, PLA-WL-7, and PLA-WL-9 biocomposites) is presented in Figure 5. modifications on the surface and cross‐sections split in liquid N2. A graphical representation of the samples' SEM images (PLA, PLA‐WL‐7, and PLA‐WL‐9 biocomposites) is presented in Figure 5.

**Figure 5.** The SEM micrographs of the surface ((**a**) PLA and (**b**) PLA‐WL‐7 biocomposites), fracture surface ((**c**) PLA and (**d**) PLA‐WL‐7 biocomposites), and fracture surface of PLA‐WL‐9 in two different magnifications ((**e**) 1KX and (**f**) 10 KX). **Figure 5.** The SEM micrographs of the surface ((**a**) PLA and (**b**) PLA-WL-7 biocomposites), fracture surface ((**c**) PLA and (**d**) PLA-WL-7 biocomposites), and fracture surface of PLA-WL-9 in two different magnifications ((**e**) 1KX and (**f**) 10 KX).

and WL powder was well dispersed between the PLA matrixes. No micro‐domains were observed in the developed PLA‐WL composites. The homogeneous surface resulted from the obtained good dispersion of WL in the PLA matrix during the process, confirming the composites' enhanced mechanical performance containing 7% WL. The optimal mechanical and thermal characteristics were determined for the PLA‐WL‐7 sample. These improvements were proved by illustrating WL proper dispersion in the polymer matrix. A powerful filler and matrix engagement due to the lignin's paste impact was evident in the images. The SEM micrographs of the fracture surface for the PLA‐WL‐9 sample are illustrated in Figure 5e,f. Some agglomerations of WL are detectable within the image. The results correspond with the mechanical testing results due to the reduced mechanical

The developed biocomposites' contact angles determined the surface wettability (Figure 6). The contact angles increased from about 46° to 66° when the WL was incorporated into the PLA matrix at 7 wt % concentration. It was observed that the addition of phenolic compounds which are presented in the WL enhanced the hydrophobicity of the composite surface. The reason for this hydrophobicity is the emplacement of the WL with hydrophobic phenolic functional groups in the micro spaces of the PLA matrix. The data achieved from the contact angle tests agree with the antibacterial activity test, which is reported in the next section. This study may serve as a stepping stone for future investigations to solve some of the critical problems of bioplastic industries by preventing moisture diffusion and inducing the antibacterial activity into a

The PLA had a smooth surface with some voids related to the humidity vaporization from the surface during the hot pressing process. The uniform structure was detected for PLA in both surface and cross‐section images. The WL powder's presence in the structure of the PLA‐WL‐7 biocomposite was completely observable from changes in the

strength of this sample compared with the PLA‐WL‐7 composite.

biodegradable packaging material, i.e., PLA.

*3.5. Contact Angle*

The PLA had a smooth surface with some voids related to the humidity vaporization from the surface during the hot pressing process. The uniform structure was detected for PLA in both surface and cross-section images. The WL powder's presence in the structure of the PLA-WL-7 biocomposite was completely observable from changes in the morphology in the SEM micrographs of this sample. Different phases were detectable, and WL powder was well dispersed between the PLA matrixes. No micro-domains were observed in the developed PLA-WL composites. The homogeneous surface resulted from the obtained good dispersion of WL in the PLA matrix during the process, confirming the composites' enhanced mechanical performance containing 7% WL. The optimal mechanical and thermal characteristics were determined for the PLA-WL-7 sample. These improvements were proved by illustrating WL proper dispersion in the polymer matrix. A powerful filler and matrix engagement due to the lignin's paste impact was evident in the images. The SEM micrographs of the fracture surface for the PLA-WL-9 sample are illustrated in Figure 5e,f. Some agglomerations of WL are detectable within the image. The results correspond with the mechanical testing results due to the reduced mechanical strength of this sample compared with the PLA-WL-7 composite.

#### *3.5. Contact Angle*

The developed biocomposites' contact angles determined the surface wettability (Figure 6). The contact angles increased from about 46◦ to 66◦ when the WL was incorporated into the PLA matrix at 7 wt % concentration. It was observed that the addition of phenolic compounds which are presented in the WL enhanced the hydrophobicity of the composite surface. The reason for this hydrophobicity is the emplacement of the WL with hydrophobic phenolic functional groups in the micro spaces of the PLA matrix. The data achieved from the contact angle tests agree with the antibacterial activity test, which is reported in the next section. This study may serve as a stepping stone for future investigations to solve some of the critical problems of bioplastic industries by preventing moisture diffusion and inducing the antibacterial activity into a biodegradable packaging material, i.e., PLA. *Polymers* **2022**, *14*, x FOR PEER REVIEW 10 of 14

**Figure 6.** The contact angle images for fabricated biocomposites ((**a**) PLA and (**b**) PLA‐WL‐7). **Figure 6.** The contact angle images for fabricated biocomposites ((**a**) PLA and (**b**) PLA-WL-7).

#### *3.6. Antibacterial Behavior 3.6. Antibacterial Behavior*

The materials' antibacterial activity is associated with their physical and chemical properties such as the functional groups, dispersion of antibacterial agents, and surface roughness. It is well known that bacteria tend to be cultured on hydrophilic surfaces, and thus, hydrophobic surfaces may inhibit bacterial growth [68–70]. For examining the antibacterial characteristics of PLA‐WL biocomposites, the association of the *E. coli* bacteria with neat PLA and PLA‐WL was mentioned. Figure 7 indicates composites' behavior in the forms of cytotoxic effects. The density of the bacterial growth around the neat PLA indicates that there is no antimicrobial activity in the neat PLA structure. WL powder insertion into the PLA matrix structure led to a lower microbe density across the test sheet, suggesting an inhibitory effect. The results illustrated that the PLA‐WL‐3 has no bacterial growth inhibition, unlike the neat PLA sample. On the other hand, PLA‐WL‐ The materials' antibacterial activity is associated with their physical and chemical properties such as the functional groups, dispersion of antibacterial agents, and surface roughness. It is well known that bacteria tend to be cultured on hydrophilic surfaces, and thus, hydrophobic surfaces may inhibit bacterial growth [68–70]. For examining the antibacterial characteristics of PLA-WL biocomposites, the association of the *E. coli* bacteria with neat PLA and PLA-WL was mentioned. Figure 7 indicates composites' behavior in the forms of cytotoxic effects. The density of the bacterial growth around the neat PLA indicates that there is no antimicrobial activity in the neat PLA structure. WL powder insertion into the PLA matrix structure led to a lower microbe density across the test sheet, suggesting an inhibitory effect. The results illustrated that the PLA-WL-3 has no bacterial growth inhibition, unlike the neat PLA sample. On the other hand, PLA-WL-5, PLA-WL-7

5, PLA‐WL‐7 and PLA‐WL‐9 have shown growth inhibition zones, and this activity is more indicatable in PLA‐WL‐9. This result proved the claim of the antibacterial effect of

proved their potential use in various packaging applications to inhibit bacterial growth. The authors postulate that phenolic compounds in the WL structure caused the PLA‐WL

(**a**) (**b**) **Figure 7.** The antibacterial activity of the prepared biocomposites ((**a**) PLA and PLA‐WL‐3 and (**b**)

The results indicated that the WL powder filler induction in the PLA matrix could enhance the polymer's mechanical characteristics. WL significantly improved all of the

composite's antibacterial properties.

PLA‐WL‐5, PLA‐WL‐7, and PLA‐WL‐9) against *E. coli.*

**4. Conclusions**

and PLA-WL-9 have shown growth inhibition zones, and this activity is more indicatable in PLA-WL-9. This result proved the claim of the antibacterial effect of WL on *E. coli* growth. The expressed antimicrobial behavior of the PLA-WL composites proved their potential use in various packaging applications to inhibit bacterial growth. The authors postulate that phenolic compounds in the WL structure caused the PLA-WL composite's antibacterial properties. 5, PLA‐WL‐7 and PLA‐WL‐9 have shown growth inhibition zones, and this activity is more indicatable in PLA‐WL‐9. This result proved the claim of the antibacterial effect of WL on *E. coli* growth. The expressed antimicrobial behavior of the PLA‐WL composites proved their potential use in various packaging applications to inhibit bacterial growth. The authors postulate that phenolic compounds in the WL structure caused the PLA‐WL composite's antibacterial properties.

(**a**) (**b**)

The materials' antibacterial activity is associated with their physical and chemical properties such as the functional groups, dispersion of antibacterial agents, and surface roughness. It is well known that bacteria tend to be cultured on hydrophilic surfaces, and thus, hydrophobic surfaces may inhibit bacterial growth [68–70]. For examining the antibacterial characteristics of PLA‐WL biocomposites, the association of the *E. coli* bacteria with neat PLA and PLA‐WL was mentioned. Figure 7 indicates composites' behavior in the forms of cytotoxic effects. The density of the bacterial growth around the neat PLA indicates that there is no antimicrobial activity in the neat PLA structure. WL powder insertion into the PLA matrix structure led to a lower microbe density across the test sheet, suggesting an inhibitory effect. The results illustrated that the PLA‐WL‐3 has no bacterial growth inhibition, unlike the neat PLA sample. On the other hand, PLA‐WL‐

**Figure 6.** The contact angle images for fabricated biocomposites ((**a**) PLA and (**b**) PLA‐WL‐7).

*Polymers* **2022**, *14*, x FOR PEER REVIEW 10 of 14

**Figure 7.** The antibacterial activity of the prepared biocomposites ((**a**) PLA and PLA‐WL‐3 and (**b**) PLA‐WL‐5, PLA‐WL‐7, and PLA‐WL‐9) against *E. coli.* **Figure 7.** The antibacterial activity of the prepared biocomposites ((**a**) PLA and PLA-WL-3 and (**b**) PLA-WL-5, PLA-WL-7, and PLA-WL-9) against *E. coli*.

#### **4. Conclusions 4. Conclusions**

*3.6. Antibacterial Behavior*

The results indicated that the WL powder filler induction in the PLA matrix could enhance the polymer's mechanical characteristics. WL significantly improved all of the The results indicated that the WL powder filler induction in the PLA matrix could enhance the polymer's mechanical characteristics. WL significantly improved all of the PLA's mechanical properties, such as tensile strength, elongation at break, and hardness. The addition of WL resulted in an enhanced Charpy impact strength of the biocomposites. The PLA's thermal stability and crystallization behavior were also improved with the addition of WL as a filler. The surface hydrophobicity of the PLA-WL biocomposites was improved compared to the neat PLA sample. The antibacterial activity is another benefit that the WL added to the PLA. In bio-industries, preventing moisture diffusion and bacterial growth are very significant challenges. The induction of these properties to the PLA as a biopolymer could make the WL suitable as a filler for various industrial applications.

**Author Contributions:** Conceptualization, M.H.S.; methodology, M.H.S.; investigation, P.P.S. and M.N.A.; resources, M.H.S.; writing—original draft preparation, P.P.S.; writing—review and editing, M.H.S., P.A. and V.S.; visualization, P.P.S.; supervision, M.H.S.; project administration, M.H.S.; funding acquisition, M.H.S. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research work was supported by project No. P/8/995 carried out at the Amol University of Special Modern Technologies, Amol, Iran. This research was also supported by the project No. HИC-Б-1145/04.2021 "Development, Properties, and Application of Eco-Friendly Wood-Based Composites" carried out at the University of Forestry, Sofia, Bulgaria.

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** Not applicable.

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


**Julian Jamison**

Department of Economics, University of Exeter Business School, Rennes Drive, Exeter EX4 4PU, UK<EMAIL_ADDRESS>
Academic Editor: Ulrich Berger Received: 8 June 2020; Accepted: 5 August 2020; Published: 20 August 2020

**Abstract:** Intuitively, we expect that players who are allowed to engage in costless communication before playing a game would be foolish to agree on an inefficient outcome amongst the set of equilibria. At the same time, however, such preplay communication has been suggested as a rationale for expecting Nash equilibria in general. This paper presents a plausible formal model of cheap talk that distinguishes and resolves these possibilities. Players are assumed to have an unlimited opportunity to send messages before playing an arbitrary game. Using an extension of fictitious play beliefs, minimal assumptions are made concerning which messages about future actions are credible and hence contribute to final beliefs. In this environment, it is shown that meaningful communication among players leads to a Nash equilibrium (NE) of the action game. Within the set of NE, efficiency then turns out to be a consequence of imposing optimality on the cheap talk portion of the extended game. This finding contrasts with previous "babbling" results.

**Keywords:** strategic communication; two-stage games; pareto efficient equilibria; belief formation


**Abstract**

Soybean is one of the most widely planted and used legumes in the world due to its valuable seed composition. The many significant agronomic practices that are utilized in soybean production are highlighted with an emphasis on those used during the pregrowing season and growing season. The various pests of soybeans and the pest management strategies used to control them are described with special attention to insects, weeds, bacteria, fungi, and nematodes. The multitude of soybean uses for livestock and human consumption, and its industrial uses are discussed in this chapter. Additionally, the conventional breeding and genetic engineering attempts to improve soybean protein, oil, and sucrose content as well as eliminate the antinutritional factors, such as trypsin inhibitors, raffinose, stachyose, and phytate, are examined. In this chapter, the various management practices, uses, and breeding efforts of soybean will be discussed.

**Keywords:** agronomic practices, pest management, soybean uses, breeding, genetic engineering

## **1. Introduction**

Soybean (*Glycine max*) is one of the most valuable, versatile, and nutritionally important legumes globally. It can be grown in a multitude of environments, using a variety of management practices, and for diverse end-user purposes. In 2018, roughly 398 million tons of soybeans were produced worldwide which accounted for 61% of overall oilseed production and 6% of the world's arable land use [1–3]. The United States, Brazil, and Argentina constituted approximately 81% of international soybean production, producing 34, 32, and 15%, respectively [4, 5]. Soybean seed composition and its main components, meal and oil, are the driving forces behind crop production that has increased nearly 350% since 1987 [5]. Soybean meal is intricately connected to the food supply through direct food consumption and indirect consumption as a large source of livestock feed. Soy oil provides great versatility with uses in food and beverage, wax, construction, cosmetics, plastics, and fuel.

Soybean originated in East Asia and has been cultivated in China for millennia. It is estimated that the domestication event from wild soybean (*Glycine soja*) occurred during the Shang Dynasty, 1700–1100 B.C. [6]. While no longer the largest producer, China and other Asian countries continue to incorporate large quantities of traditional and innovative soy foods into their diet. In 2018, China was the largest customer for United States whole soybeans, importing over \$3 billion worth [7]. The United States

and western countries mainly utilize soybean indirectly in the food supply as livestock feed and food ingredients such as textured vegetable protein and protein isolates. However, as more consumers are looking for plant-based protein in their diet, soy foods will become a globally viable alternative to animal protein. As the soybean appetite has increased and transformed, scientific developments have also improved soybean production through agronomic, management, and genetic methods to meet demand.


Author details

Gisela Gaina1,2\*, Magdalena Budisteanu1 , Emilia Manole1 and Elena Ionica2

1 Victor Babes National Institute of Pathology, Bucharest, Romania

2 Department of Biochemistry and Molecular Biology, University of Bucharest, Bucharest, Romania

\*Address all correspondence to<EMAIL_ADDRESS><EMAIL_ADDRESS>
© 2019 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.


**Expression of Tumor Necrosis Factor-Alpha (TNF- TNF- Converting Enzyme and Matrix Metalloproteinase-3 in SAPHO Syndrome Synovium - A Rare Case Accompanied by Acrodermatitis Continua of Hallopeau: A Case Report and Review of Anti-TNF- Therapy**

Koichiro Komiya1, Nobuki Terada1,

Yoshikazu Mizoguchi2 and Harumoto Yamada3 *1Department of Orthopaedic Surgery, Fujita Health University Second Hospital 2Department of Pathology, Fujita Health University Second Hospital 3Department of Orthopaedic Surgery, Fujita Health University Japan*


*3.2. Vertical Smoke Temperature Distribution in Atrium*

The fire produces a large amount of smoke, and releases huge heat to produce a high temperature. A high temperature environment and toxic smoke will bring difficulties to the safe evacuation of trapped people. Long-term exposure to smoke will seriously damage people's physical functions, and they may lose the ability to escape. The study of the temperature distribution law of smoke in an atrium can not only provide a reference for building fire design, but also provide guidance for personnel evacuation during a fire. Figures 7–11 are the variation charts of vertical smoke temperature in the atrium under five different working conditions, and six measurement points at different positions are selected as analysis objects in the vertical direction: V1 (17.3 m), V4 (14.3 m), V7 (11.3 m), V10 (8.3 m), V13 (5.3 m), V16 (2.3 m). *Fire* **2023**, *6*, x FOR PEER REVIEW 8 of 19 ceiling and formed a stable smoke layer, which continues to settle. Until the extinguishing phase, smoke is continuously generated and fills the entire atrium. Figure 6 shows the schematic diagram of smoke spread under working Cases 1~5.

Case 1

1.

0

0

100

200

300

Temperature/℃

2.

400

500

20 s 100 s 300 s selected as analysis objects in the vertical direction: V1 (17.3 m), V4 (14.3 m), V7 (11.3 m),

> V1 V4 V7 V10 V13

V16

**Figure 6.** Comparison of smoke layer thickness at different times in Cases 1~5. **Figure 6.** Comparison of smoke layer thickness at different times in Cases 1~5. V10 (8.3 m), V13 (5.3 m), V16 (2.3 m).

sonable smoke exhaust system. **Figure 7.** Temperature variation of measuring points at different heights above the atrium in Case **Figure 7.** Temperature variation of measuring points at different heights above the atrium in Case 1.

100 200 300 400 500 600 700

Time/s

**Figure 8.** Temperature variation of measuring points at different heights above the atrium in Case

100 200 300 400 500 600 700 800 900

**Figure 7.** Temperature variation of measuring points at different heights above the atrium in Case

V16 (Case1)

Time/s

*3.2. Vertical Smoke Temperature Distribution in Atrium*

V10 (8.3 m), V13 (5.3 m), V16 (2.3 m).

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The fire produces a large amount of smoke, and releases huge heat to produce a high temperature. A high temperature environment and toxic smoke will bring difficulties to the safe evacuation of trapped people. Long-term exposure to smoke will seriously damage people's physical functions, and they may lose the ability to escape. The study of the temperature distribution law of smoke in an atrium can not only provide a reference for building fire design, but also provide guidance for personnel evacuation during a fire. Figures 7–11 are the variation charts of vertical smoke temperature in the atrium under five different working conditions, and six measurement points at different positions are selected as analysis objects in the vertical direction: V1 (17.3 m), V4 (14.3 m), V7 (11.3 m),

> V1 V4 V7 V10 V13

**Figure 8.** Temperature variation of measuring points at different heights above the atrium in Case **Figure 8.** Temperature variation of measuring points at different heights above the atrium in Case 2.

V1

**Figure 9.** Temperature variation of measuring points at different heights above the atrium in Case **Figure 9.** Temperature variation of measuring points at different heights above the atrium in Case 3. 3.

**Figure 10.** Temperature variation of measuring points at different heights above the atrium in Case **Figure 10.** Temperature variation of measuring points at different heights above the atrium in Case 4.

100 200 300 400 500 600

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**Figure 11.** Temperature variation of measuring points at different heights above the atrium in Case

**Figure 11.** Temperature variation of measuring points at different heights above the atrium in Case

Time/s

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**Figure 10.** Temperature variation of measuring points at different heights above the atrium in Case

 V1 V4 V7 V10 V13

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V16 (Case4)

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**Figure 10.** Temperature variation of measuring points at different heights above the atrium in Case

Time/s

**Figure 9.** Temperature variation of measuring points at different heights above the atrium in Case

V16 (Case3)

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**Figure 11.** Temperature variation of measuring points at different heights above the atrium in Case **Figure 11.** Temperature variation of measuring points at different heights above the atrium in Case 5.

5. It can be seen that the change trend of smoke temperature rise under different working conditions is basically similar. Regardless of the heat release rate and whether the smoke exhaust system is turned on, the rise of smoke temperature has successively experienced the three stages of rise, fluctuation within a certain range and decrease, which is consistent with the three stages of occurrence and development of fire explained by combustion theory. In the stable combustion stage of the ignition source, the smoke temperature will fluctuate within a certain range, and we regard it as the stable stage of the smoke temperature rise (Figures 7–11). Under different working conditions, the stabilization stage of smoke temperature rise is different, which is mainly reflected in the stable value of smoke temperature rise and the time when the stable section disappears.

When a fire starts, the heat released by the fire is limited, and the rise of smoke temperature is relatively slow. Then, the fire becomes violent, and the temperature gradient increases rapidly and it quickly reaches the maximum temperature. Comparing Figures 7, 9 and 10, it can be seen that under the same natural filling conditions, the temperature stability values of the measurement point closest to the fire source under different heat release rate in Case 1 (1.5 MW), Case 3 (0.7 MW) and Case 4 (0.34 MW) decrease sequentially. This indicates that the greater the heat release rate is, the greater the average temperature of the smoke in the atrium is. The greater the distance between the smoke and the fire source above the atrium, the lower the temperature of the smoke is; that is, the thermocouple closest to the fire source has the highest temperature and the thermocouple farthest away has the lowest temperature. As the smoke moves far away in the upper layers, heat is gradually dissipated. However, the time it takes for the smoke temperature stabilization to disappear is not much different.  This is because the natural smoke exhaust strategy only opens the top glass window of the atrium to accelerate the flow of smoke near it, so that the heat exchange is accelerated, while the position near the fire source far from the glass window receives little impact. After turning on the mechanical smoke exhaust system (Cases 4 and 5), the temperature decreases, which also causes the temperature stability section to disappear earlier.

Figure 12 shows the change of the average temperature of the vertical smoke stabilization section of the atrium with the height of the fire source center under the conditions of Cases 1~5. It can be clearly known that the uniform temperature of the smoke stabilization section is directly related to the heat release rate of the fire. In addition, the use of natural smoke exhaust (Cases 1 and 2) or mechanical smoke exhaust (Cases 4 and 5) also has an impact on the uniform temperature of the smoke stabilization section. Turning on the

smoke exhaust system will accelerate the heat exchange between the smoke and outside, so that the smoke cooling temperature is reduced. However, from Figure 12, the magnitude of this temperature reduction is not obvious, indicating that a single smoke exhaust mode has a poor effect on the flow control of smoke. *Fire* **2023**, *6*, x FOR PEER REVIEW 13 of 19300 350 Case 1 Case 2 Case 3 Case 4 Case 5

*Fire* **2023**, *6*, x FOR PEER REVIEW 13 of 19

250

400

**Figure 12.** Variation of vertical smoke average temperature in atrium with height from fire source center in Cases 1~5. **Figure 12.** Variation of vertical smoke average temperature in atrium with height from fire source center in Cases 1~5. In orderto describe the distribution of vertical smoke temperature in the atrium more intuitively and accurately, we introduced the McCaffrey plume model [19]. The McCaf-

In orderto describe the distribution of vertical smoke temperature in the atrium more intuitively and accurately, we introduced the McCaffrey plume model [19]. The McCaffrey plume model is a semi-empirical formula, which is fitted by a large number of experimental results. It is applicable to the calculation of plume mass flow under the condition of both small area fires and large area fires, maintaining certain universality. It is widely used to study the flame plume in building fires [20–23]. The expression is as follows: In order to describe the distribution of vertical smoke temperature in the atrium more intuitively and accurately, we introduced the McCaffrey plume model [19]. The McCaffrey plume model is a semi-empirical formula, which is fitted by a large number of experimental results. It is applicable to the calculation of plume mass flow under the condition of both small area fires and large area fires, maintaining certain universality. It is widely used to study the flame plume in building fires [20–23]. The expression is as follows: frey plume model is a semi-empirical formula, which is fitted by a large number of experimental results. It is applicable to the calculation of plume mass flow under the condition of both small area fires and large area fires, maintaining certain universality. It is widely used to study the flame plume in building fires [20–23]. The expression is as follows:2 2 1 z *TT* − =

$$
\Delta T = \left(\frac{\kappa}{0.9 \cdot \sqrt{2\text{g}}}\right)^2 \left(\frac{\text{z}}{\text{\textdegree\%}}\right)^{2\eta - 1} \cdot T\_{\infty} \tag{2}
$$

$$
\text{\textdegree \dots \text{\textdegree} \dots \text{\textdegree} \dots \text{\textdegree} \dots \text{\textdegree}} \tag{3}
$$

2/5

(2)

20

**[m/kW2/5]**

**[m/kW2/5]**

ambient temperature, K; *g* is the acceleration of gravity, 9.81 m/s2 ; *Q* is the heat release rate of the fire, kW; z is the height, m; *T* is the ambient temperature, 293 K. The three zones of the axisymmetric buoyant plume are shown in Figure 13. The values of κ and η of the McCaffrey plume model are shown in Table 3. where ∆*T* represents the difference between the temperature at appointed altitude and the ambient temperature, K; *g* is the acceleration of gravity, 9.81 m/s2 ; . *Q* is the heat release rate of the fire, kW; z is the height, m; *T*∞ is the ambient temperature, 293 K. The three zones of the axisymmetric buoyant plume are shown in Figure 13. The values of κ and η of the McCaffrey plume model are shown in Table 3. rate of the fire, kW; z is the height, m; *T* is the ambient temperature, 293 K. The three zones of the axisymmetric buoyant plume are shown in Figure 13. The values of κ and η of the McCaffrey plume model are shown in Table 3.

where ∆*T* represents the difference between the temperature at appointed altitude and the

**Table 3.** Values of and .

**Zone**

**Zone**

**Table 3.** Values of and .

**Figure 13.** The three zones of the axisymmetric buoyant plume. **Figure 13.** The three zones of the axisymmetric buoyant plume. **Figure 13.** The three zones of the axisymmetric buoyant plume.

2/5 *z Q*

2/5 *z Q*

Intermittent flame zone 0.08–0.2 1.9 [m/kW1/5 s] 0

Plume zone >0.2 1.1 [m4/3/kW1/3 s] −1/3

Continuous flame zone <0.08 6.8 [m1/2/s] 1/2 Intermittent flame zone 0.08–0.2 1.9 [m/kW1/5 s] 0

Plume zone >0.2 1.1 [m4/3/kW1/3 s] −1/3

However, considering the factors of multi-fire flame fusion, air flow and smoke exhaust system in this working condition, the McCaffrey plume model above needs to be corrected. We still use *z*/ . *Q* 2/5 as the independent variable to draw the scatter diagram of smoke temperature rise changing with the vertical height and the heat release rate of the fire source, and then carry out subsection fitting correction, as shown in Figure 14. However, considering the factors of multi-fire flame fusion, air flow and smoke exhaust system in this working condition, the McCaffrey plume model above needs to be corrected. We still use 2/5 *z Q* as the independent variable to draw the scatter diagram of smoke temperature rise changing with the vertical height and the heat release rate of the fire source, and then carry out subsection fitting correction, as shown in Figure 14.

**Figure 14.** Variation of smoke temperature rise with 2/5*z Q* . **Figure 14.** Variation of smoke temperature rise with *z*/ . *Q* 2/5 .

The modified *κ* and *η* values are shown in Table 4. The modified *κ* and *η* values are shown in Table 4.

**Table 4.** Modified values of and . **Table 4.** Modified values of *κ* and *η*.

where

0 *T*

*T*

of atrium, 19.8 m.

### *3.3. Horizontal Smoke Temperature Distribution under the Ceiling of the Atrium 3.3. Horizontal Smoke Temperature Distribution under the Ceiling of the Atrium*

The temperature distribution below the atrium ceiling is similar to ceiling jet. The smoke rises from the atrium fire source to the ceiling, and then spreads around, filling the entire atrium. Under all cases, the smoke temperature reached a maximum value directly above the fire source, and decreased on the east and west sides as it moved away from the center point, showing an exponential attenuation mode. The temperature attenuation rate is not only directly related to the heat release rate, but also has a certain relationship with the smoke exhaust system. In order to analyze this attenuation relationship more intuitively and qualitatively, we make the average temperature of the smoke under the atrium ceiling dimensionless according to the following equation [24],The temperature distribution below the atrium ceiling is similar to ceiling jet. The smoke rises from the atrium fire source to the ceiling, and then spreads around, filling the entire atrium. Under all cases, the smoke temperature reached a maximum value directly above the fire source, and decreased on the east and west sides as it moved away from the center point, showing an exponential attenuation mode. The temperature attenuation rate is not only directly related to the heat release rate, but also has a certain relationship with the smoke exhaust system. In order to analyze this attenuation relationship more intuitively and qualitatively, we make the average temperature of the smoke under the atrium ceiling dimensionless according to the following equation [24],

0

represents the temperature at the center position directly above the fire source, °C;

distance from fire source; *x* is the distance from the center point, m; *H* is the clear height

represents the temperature of the measurement point in the '*x*' direction, °C;

$$
\Delta T/\Delta T\_0 = e^{-a\mathbf{x}/H} \tag{3}
$$

where ∆*T* represents the temperature of the measurement point in the '*x*' direction, ◦C; ∆*T*0 represents the temperature at the center position directly above the fire source, ◦C; *α* is the attenuation coefficient of dimensionless smoke temperature rise with dimensionless distance from fire source; *x* is the distance from the center point, m; *H* is the clear height of atrium, 19.8 m. *Fire* **2023**, *6*, x FOR PEER REVIEW 15 of 19 Figure 15 shows the variation of the horizontal dimensionless smoke temperature

> Figure 15 shows the variation of the horizontal dimensionless smoke temperature rise ∆*T*/∆*T*0 with the dimensionless distance *x/H* from the fire source at the height of 18.3 m below the atrium ceiling under various working conditions. The correlation coefficient of the fitting curve reaches more than 0.95 under all cases, indicating that the consistency between the data and the model was good. Table 5 shows the attenuation coefficient of dimensionless smoke temperature rise with dimensionless distance from the fire source. rise 0 *T T* / with the dimensionless distance *x/H* from the fire source at the height of 18.3 m below the atrium ceiling under various working conditions. The correlation coefficient of the fitting curve reaches more than 0.95 under all cases, indicating that the consistency between the data and the model was good. Table 5 shows the attenuation coefficient of dimensionless smoke temperature rise with dimensionless distance from the fire source.

**Figure 15.** *Cont*.

*Fire* **2023**, *6*, x FOR PEER REVIEW 16 of 19

**Figure 15.** Variation of dimensionless smoke temperature rise 0 *T T* / under atrium ceiling with **Figure 15.** Variation of dimensionless smoke temperature rise ∆*T*/∆*T*0 under atrium ceiling with dimensionless distance from fire source *x/H* in Cases 1~5.

dimensionless distance from fire source *x/H* in Cases 1~5.

**Table 5.** Attenuation coefficients of dimensionless smoke temperature rise with dimensionless distance from fire source.

It can be seen from Figure 15 that the variation of lateral dimensionless smoke temperature rise under the atrium ceiling with the distance between dimensionless and fire source has a greater relationship with the heat release rate. The larger the heat release rate is, the higher the smoke temperature in the atrium is, and the greater the mass flow rate is, also the faster the smoke spreads, resulting in a smaller attenuation coefficient. The smoke temperature shows a trend of attenuation from the central position to both sides, and the left and right sides are basically symmetrically distributed, but there are still slight differences. Possibly because the east side of the building has a protruding space, as well as the obstruction of the smoke barrier, the east side of the smoke accumulates in a small area, and the heat is not dispersed, resulting in a smaller attenuation rate than the west side. Analyzing the influence of different experimental scenarios, it is found that the dimensionless temperature rise attenuation rate is also related to the use of the smoke exhaust system. Specifically, after opening the natural smoke exhaust vents (Cases 1 and 2) and turning on the mechanical smoke exhaust (Cases 4 and 5), the smoke flow is accelerated, and the heat exchange with the external environment is promoted, bringing the cooling effect to the smoke. Therefore, it will lead to the increase of the attenuation coefficient, which means that the attenuation rate also increases. Additionally, the effect of mechanical smoke exhaust is better than that of natural smoke exhaust.


**3. Shifting the educational approach**

Promoting participation in PA and exercise entails acquired perceptions of the body and already created associations between the body and the mind in relation

to personal attitudes, beliefs and appreciations from previous attempts to become physically active [30]. During this process, various implicit and explicit mechanisms are underway creating a unique response for the individual.

Using modern psychoanalytic views of unconscious processes representing wishful, fearful, and associated notions, Bendor [31] examined the main reasons behind exercise avoidance resulting in physical inactivity in modern society. Based on the views of practicing psychoanalysts, his results supported that exercise avoidance comes as a product of fear of identity change, learned disregard of own body, and repressed traumatic associations to exercise. Bendor's findings highlight the importance of unconscious processes over exercise adoption [29] in various populations in need and clearly call for the adaption of new exercise promotion and education methods [22, 28].

When it comes to exercise adoption, negative sentiments, fear and/or unconscious processes have been uncovered in coronary heart patients populations [32, 33], and community-dwelling osteoporotic older adults [34]. On the contrary, enjoyment and positive feelings are reported by young adult populations who actively participate in exercise behaviours [35] with positive feelings of valence and calmness supporting exercise participation in real life samples of healthy adults [36].

At the same time, very often messages calling for changing health behaviours (i.e. eating patterns, physical activity, smoking cessation) are based on appeals to personal responsibility, stigmatisation, controlling and inequality, that are ubiquitous around us [37]. This type of messages imply that illness or disable states are based on lack of responsibility, leading to blames of accusation to the sufferer (i.e. weak character) rather than social (lack of financial ability), environmental (i.e. relevant pollutants) or structural (i.e. disadvantaged working conditions) causes, contributing to the creation of stigma, fear and guilt [38]. The same type of messages are still making the most out of the exercise promotion campaigns aiming to change intentions and attitudes towards more active lifestyles based on cure and well-being rather than pleasures experienced during exercise [39].

Yet, it is not clear that those messages are capable of creating real change contributing to more active lifestyles [21]. Prioritising health over other behaviours by creating guilt and pointing out an inconsistency between personal standards and own behaviour having the goal of remorse and pointing out personal responsibility [40], seems to be successful in shifting health attitudes [41]. However, those changes are only related to initial stages of behavioural change, influencing attitudes and intentions to act towards more health-related behaviours, with their long-term effects still unexplored [40].

Criticism has been expressed in the past around the ways physical activity and exercise related concepts and resources have been conveyed to the general public in a non-understandable manner contributing to confusion as health related resources are not matching the recommended readability standards of the general public [42]. Same results were obtained from Thomas and Cardinal [43], showing that most of written PA educational resources are presented in a complicated and non-understandable format for the great majority of the American population. When it comes to PA and exercise literacy there seems to be an existing gap between what experts consider important to provide and the type of information required for the general public to change, becoming more physically active.

#### **4. The importance of health literacy**

Lack of knowledge of critical features that generate a health condition and low skills in obtaining, processing, understanding, and communicating health-related

#### *Design Thinking Applications in Physical Activity and Exercise Literacy DOI: http://dx.doi.org/10.5772/intechopen.97479*

information are critical components for supporting health [44]. Hence, opportunities for health-related educational sessions are important for improving health status in various population segments.

Health Literacy (HL) is related to the capacities of people to appreciate, realise, and meet the complex demands of health in modern society and its requirements. In their seminal article, Sørensen, Van den Broucke, Fullam et al. [45] defined HL as "entailing people's knowledge, motivation and competences to access, understand, appraise, and apply health information in order to make judgments and take decisions in everyday life concerning healthcare, disease prevention and health promotion to maintain or improve quality of life during the life course" (p. 3). Health literate individuals are in position to contextualise and appreciate personal needs supporting their health, their close ones and their community, understanding the most influential factors for retaining wellbeing and taking steps towards meeting those. It is about taking control and responsibility of one's own health as well as the health of their loved ones and their community [46].

It can be easily confused with academic literacy and the notion of well-educated approach and familiarity with literature. However, during the second half of the 20th century the combination of literacy to health has been expanding denoting not just the potential of personal growth and individual transformation as a result of such procedure but also the contextual and social transformation with its capacity to influence economic growth, and social, political and cultural changes [47].

Four distinct abilities are being assigned to HL. These are, a. the ability to seeking, accessing and obtaining health information, b. the ability to comprehend health information that is accessed, c. the ability to interpret filter and evaluate health information and d. the ability to make a decision to maintain and improve health through conscious decision making [45]. These four types of ability highlight the importance of availability of needed resources, and the opportunity to appreciate connections among behavioural choices and health outcomes [48].

The need for HL supports recent models of health care reinforcing the importance of education and best practices starting from a micro level (self-care or else person-centred) which are based on 7 pillars of health promotion: 1. knowledge and health literacy, 2. mental well-being, self-awareness and agency, 3. physical activity, 4.healthy eating, 5. risk avoidance, 6. good hygiene, and 7. rational use of products and services [49]. One of these pillars having extended effects on quality of life, physical and mental health, reduction of premature mortality and avoidance of morbidity is regular participation in physical activity (PA) behaviours [50].

A perspective of the Rogerian proposal of HL is based on the view that a successful health education procedure needs to be mutli-dimensional, personcentred and based on a partnership between the eager professional to train and educate and the individual willing to act based on available resources while placing health as a priority [51]. An explanation of this standpoint defines that, "health education is a continuous, dynamic, complex and planned teaching-learning process throughout the lifespan and in different settings that is implemented through an equitable and negotiated client and health professional 'partnership' to facilitate and empower the person to promote/initiate lifestyle-related behavioural changes that promote positive health status outcomes" [51], (p. 133). This view suggests that boundaries and choices in each health promotion relationship are well-placed within each individual deciding the point the affiliation with the educator begins and ends, with related partnerships based on mutual responsibility, collaboration, freedom of choice, equity and autonomy [52]. When health education is lacking the above elements, is likely to fail to recognise and integrate the recipients' preferences and requests risking being ineffective in the short or long term [53].