**6. Inbreeding and disease incidence**

Inbreeding is the production of offspring from mating or breeding of individuals or organisms that are closely related [25]. It can be technically defined as mating of a pair of animals with relationship that is closer than the average level within the breed or population studied. In domesticated animals, inbreeding can decrease the performance of animals, such as decrease in milk yield, which is termed as inbreeding depression. The genetic basis of inbreeding depression is that increased homozygosity with inbreeding increases the frequency of unfavorable genotypes within the population [25]. Inbreeding can increase the incidence of inherited diseases in the population, especially those with a recessive inheritance pattern. In our studies, we estimated inbreeding coefficients using either pedigree or genome-wide genotype data. We observed significantly higher inbreeding levels in affected GLPs (average pedigree-based inbreeding: 0.23, average genotype-based inbreeding: 0.51) in comparison to those unaffected GLPs (average pedigree-based inbreeding: 0.14, average genotype-based inbreeding: 0.48). This suggests the importance of inbreeding control in preventing inherited diseases, including cancer, in pedigree dog breeding.


**Antioxidants in Cocoa**

Editors

**Dorota Zy˙ zelewicz ˙ Joanna Oracz**

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

*Editors* Dorota Zy˙ zelewicz ˙ Lodz University of Technology Poland

Joanna Oracz Lodz University of Technology Poland

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

This is a reprint of articles from the Special Issue published online in the open access journal *Antioxidants* (ISSN 2076-3921) (available at: https://www.mdpi.com/journal/antioxidants/special issues/Antioxidants Cocoa).

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

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

**ISBN 978-3-0365-0232-8 (Hbk) ISBN 978-3-0365-0233-5 (PDF)**

© 2021 by the authors. Articles in this book are Open Access and distributed under the Creative Commons Attribution (CC BY) license, which allows users to download, copy and build upon published articles, as long as the author and publisher are properly credited, which ensures maximum dissemination and a wider impact of our publications.

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


*5.1. Application of Different Heterologous Hosts*

The selection of the heterologous host is the key to the successful application of heterologous expression. Firstly, it is important to determine the clear genetic background of the heterologous expression strain. Secondly, the heterologous expression strain should have the advantages of simple culture and fast growth. Finally, the simple and easy manipulation and high transformation efficiency of the genetic transformation were chosen. At present, the mature and commonly used expression systems in the biosynthesis of SMs of fungi include *Escherichia coli* and *Bacillus subtilis* in prokaryotes and *Saccharomyces cerevisiae* and filamentous fungi in eukaryotes, such as *Aspergillus nidulans* and *Aspergillus oryzae*. The selection of model strains should consider the sources of different genes (clusters) and the physical and chemical properties of the expressed products.

### 5.1.1. Application of Filamentous Fungi as Heterologous Hosts

With the in-depth study of filamentous fungi, there are more outstanding advantages than the model strains with, for example, prokaryotes and yeast as the heterologous hosts. The filamentous fungi can correctly splice introns from heterogenous fungi and express multiple biosynthetic genes in fungi concurrently, which plays a role in protein translation and post-modification to obtain the target product. At present, the filamentous fungi expression systems commonly used in fungal heterologous expression were mainly *A. nidulans* and *A. oryzae*.

As a filamentous fungus, *A. nidulans* has a relatively clear genetic background after years of research, and a relatively mature genetic transformation system has been established. It has been widely used as a model strain in the study of the heterologous expression of the SMs of fungi. With the combined heterologous expression of the biosynthesis gene cluster of sordarinane, derived from *Sordaria araneosa* with enzyme experiments in vitro, a group of P450 multi-enzyme systems was confirmed. The new catalytic function of the P450 family oxidases was demonstrated, which laid a foundation for the development of P450 multi-enzyme synergistic catalysis for the synthesis of new chemical entities [56]. Wei et al. identified the functions of some P450 enzymes and sesquiterpene synthetases by the heterologous expression of the BGC of asperaculin A, isolated from *A. aculeatus* [57]. Due to the failure of the gene knockout strategy, Zhong et al. heterogeneously expressed the BGC of rumbrin, isolated from *Auxarthron umbrinum*, and found an autoantibody gene, verifying that the product had anti-HIV activity [58]. In addition, the BGCs of flavunoidine-1 derived from *A. flavus* were recombinantly arranged and heterologously expressed in *A. nidulans* in different combinations, and the BGCs containing both TC and NRPS core enzymes were identified [59]. In addition, the BGCs of harzianic acid [60] and trichoxide [61] from *Trichoderma*, citridone [62] and ilicicolin H [63] from *Penicillium*, and decarestricitine from *Beauveria bassiana* were heterologously expressed in *A. nidulans*, combined with precursor feeding, which clarified the biosynthesis pathway to some extent, respectively [64].

*A. oryzae*, a heterologous host, has similar characteristics and advantages to *A. nidulans*, which is also widely used as a model strain of biosynthetic genes in the SMs of fungi. In the reconstruction of the biosynthetic pathway of phlegmacins derived from *Talaromyces* sp., an unprecedented laccase-involved unsymmetrically regioselective oxidative coupling reaction was shown, which provides a new reference for the synergistic catalytic mechanism of laccases and other proteins [65]. The BGC of funiculolides derived from *A. funiculosus* were heterogeneously expressed to elucidate the fact that α-ketoglutarate-dependent dioxygenase FncG catalyzed spirocyclopentanone [66]. By the heterologous expression of CJ-20557 biosynthetic gene clusters from *A. duricaulis*, in combination with in vitro enzyme experiments, it was clarified that the SAT domain of polyketide synthase DrcA was responsible for the formation of the depside bond, which enriched the understanding of the mechanism of fungal NR-PKS biosynthesis [67]. Chen et al. confirmed that the enzyme IlIS, a sesquiterpene synthase from *Irpex lactous*, was responsible for the synthesis of the tremulane skeleton through heterologous expression and in vitro enzymatic reaction, and four new tremulane sesquiterpene products were isolated [68]. The specific PKS synthase GrgF in the BGC of gregatin A derived from *Penicillium* sp. [69] and the trichobrasilenol terpene cyclase derived from *Trichoderma atroviride* [70] were verified by the heterologous expression of *A. oryzae*. In addition, the NRPS-PKS gene cluster from *A. candidus* was heterologously expressed to obtain a pyrrolobenzazepine alkaloid [71]. Additionally, conidiogenone [72], brevianamide A [73], and brevione E [74] derived from *Penicillium* were heterologously expressed in *A. oryzae*, combined with the precursor feeding, which is helpful in analyzing the biosynthesis pathway.

#### 5.1.2. Application of *Saccharomyces cerevisiae* as Heterologous Host

Because of the early study of the genetic background and the mature genetic manipulation system, *Saccharomyces cerevisiae* was widely used as the heterologous expression model strain in the study of the SMs of fungi in the past. Eukaryotic *S. cerevisiae* could translate proteins correctly and post-modify. Zhang et al. heterologously expressed *P. funiculosum* source chrodrimanin-type meroterpenoids BGCs and verified them in in vitro catalytic experiments to clarify the function of CdnC protein, obtaining a series of new

chrodrimanins compounds [75]. In the biosynthetic path of cyclohexanoid terpenoids derived from *Aspergillus* sp.*,* two key enzymatic functions were characterized by heterologous expression and in vitro enzymology experiments [76]. In addition, *S. cerevisiae* has also been applied for the expression of entire BGCs. *S. cerevisiae* was used as an expression vector in the heterologous expression of the BGC of the formation central C ring in the tetracyclic ergoline derived from *A. fumigatus* [77]. In the study of the biosynthesis pathway of shimalactones derived from *Emericella variecolor* [78], and flavunoidine 1 [59] and diorcinol [79] derived from *Aspergillus, S. cerevisiae* was also the heterologous expression vector. However, compared with filamentous fungi as expression vectors, *S. cerevisiae* still has some shortcomings, such as the lack of an advanced mRNA splicing system and the difficult in expressing complex BGCs; it is only suitable for expression of single or simple BGCs, which restricts its further application in the study of fungal SMs.


**Improvement of Quality of Life with Implant-Supported Mandibular Overdentures and the E**ff**ect of Implant Type and Surgical Procedure on Bone and Soft Tissue Stability: A Three-Year Prospective Split-Mouth Trial**

**Ron Doornewaard 1,\*, Maarten Glibert 1, Carine Matthys 1, Stijn Vervaeke 1, Ewald Bronkhorst 2 and Hugo de Bruyn 1,2,\***

Received: 13 May 2019; Accepted: 28 May 2019; Published: 31 May 2019

**Abstract:** In fully edentulous patients, the support of a lower dental prosthesis by two implants could improve the chewing ability, retention, and stability of the prosthesis. Despite high success rates of dental implants, complications, such as peri-implantitis, do occur. The latter is a consequence of crestal bone loss and might be related to the implant surface and peri-implant soft tissue thickness. The aim of this paper is to describe the effect of implant surface roughness and soft tissue thickness on crestal bone remodeling, peri-implant health, and patient-centered outcomes. The mandibular overdenture supported by two implants is used as a split-mouth model to scrutinize these aims. The first study compared implants placed equicrestal to implants placed biologically (i.e., dependent on site-specific soft tissue thickness). The second clinical trial compared implants with a minimally to a moderately rough implant neck. Both studies reported an improvement in oral health-related quality of life and a stable peri-implant health after three years follow-up. Only equicrestal implant placement yielded significantly higher implant surface exposure, due to the establishment of the biologic width. Within the limitations of this study, it can be concluded that an implant supported mandibular overdenture significantly improves the quality of life, with limited biologic complications and high survival rates of the implants.

**Keywords:** bone loss; dental implant; overdenture; implant survival; peri-implantitis; implant surface; soft tissue; split-mouth design; oral health-related quality of life; patient-reported outcome measures


**5. Discussion**

Due to the considerable human and monetary costs associated with workplace accidents, it is important to study various factors that help reduce mishaps [80]. Various factors

are examined to test the framework of this study. The results show a positive relationship between safety management and safety consciousness (Hypothesis 1) in the workplace. This study supports the findings of the earlier studies [81,82]. The employees are required to perform in a safer way that would not harm themselves and their co-workers [37]. This consciousness can be enhanced through developing a plan for work, reporting all the possible hazards, safety training, reporting all the hazards that actually occurred during the work, accepting the responsibility for any misconduct and taking measures to avoid them in the future, and teaching ourselves and our colleagues about preventing the accidents [38].

The safety standards and procedures enforced by the organization keep employees in touch with the use of safety procedures and can avoid dangerous situations [9]. Safety management can be made effective through safety policy, as a part of safety climate (Hypothesis 2). The policy helps coordinate the other HR policies to ensure employees' well-being. The written policies show the management's concern for safety and this written document reminds the employees about the safety standards to be implemented while at work. The written documents also provide the procedures to follow to avoid any possible health hazards [13]. The policies available lead to continuous improvements in the workplace and save all from the dangers. Another important component of safety management is the priority of providing training to the employees to avoid any uneven situation at the workplace. The avoidance of dangerous situations and compelling others to be safe by themselves and keep others safe becomes mandatory while working, thus boosting safety consciousness [41].

The managers who provide safety training as a part of a safety climate, as a priority to learn safety measures, provide an opportunity to make a safe competitive environment that is safety performance (Hypothesis 3). People try to learn as much as they can to avoid accidents, thus adding to their safety consciousness [41]. The organizations must communicate about the risks associated with work. Frequent communications can help in two ways. First, the employees become aware of the hazards associated with their work, and, second, if anything goes wrong it will be well-communicated in time to reduce the damage as much as possible [45]. Better safety management frequently transmits the principles and rules of action. This makes people mindful of safety. Preventive planning is another way to add timely emergency plans that can reduce the possible level of danger at the workplace. Involving employees in making preventive plans can enable people to think of their safety, thus making people conscious of their safety. In short, policies, training, communication, and preventive planning collectively motivate employees to remain conscious of their workplace safety for positive outcomes [44] (Hypothesis 4).

The results of this study found a positive impact of safety management on the safety climate. Safety training, communication, preventive planning, and policy-making are important for developing a common sense of safety in the organization [41]. A written declaration available to and signed by all workers reflects management's concern for safety. This puts compulsion on the employees to develop a safe climate. Moreover, the safety policy puts emphasis on commitment to continuous improvement. This leads to conducting periodic checks on the execution of prevention plans [81].

The continuous and periodic training of employees enables them to apply their safety knowledge, skills, and abilities in a manner that saves themselves and their co-workers [9]. This also helps to keep procedures in place and to check the achievement of the objectives set. Similarly, the instruction manuals or work procedures elaborated can help employees prevent accidents. The frequent communication for transmitting the principles and rules of action leads to collective awareness [45]. Moreover, the written circulars and meetings inform workers about risks associated with their work and how to prevent possible accidents. Similarly, the written circulars and meetings force employees to conduct systematic inspections periodically. This ensures the effective functioning of the whole system.

Organizations that focus on emergency plans by practicing responsible leadership can protect employees from harm. Effective organizations always have emergency plans in place. The prevention plans are based on an assessment of the risk and employees are empowered to know the possible degree of risk. They keep themselves aware of the risks and try their best to be alert while assuming risky tasks [43] (Hypothesis 6).

The results show a positive impact of the safety climate on safety performance, i.e., consistent with the results [52,58,59]. The improvement in the safety climate means reducing potential safety threats. The employees conduct periodic checks as a result of the frequent communication and training provided to them. This enhances the compliance levels and ensures safety in the workplace [81]. The timetables available for the safety checks support compliance. The periodic checks of the procedures and equipment to use keep track of the personal protection equipment and keep the inventory up to date. That further strengthens the safety performance. The predetermined plans enable employees to improve working conditions by following the standard operating procedures and minimizing the errors involved. The minimized errors save time and other resources from wastage [47].

The results confirm the positivity in the relationship of these two variables, such as the findings of Lee et al. [82] and Wong et al. [81]. The higher the knowledge of the safety standards, the greater the application of the safety standards can be ensured. Moreover, one who is convinced about the use of safety procedures can compel himself and others to remain safety-minded [63]. At times it becomes difficult for the employees to use the safety equipment, but the policies and rules enforce the adoption of safety measures. The employees who remain involved in the evaluation of the safety risks tend to show discomfort when they see other people acting dangerously [44].

In the safety-enforced environment, the employees are compelled to make sure that other people do the things that are safe and healthy. Participation in setting the safety objectives and improving safety practices also gives a sense of ensuring collective safety at the workplace by inculcating safety-mindedness [52]. Compliance with the safety standards encourages employees to avoid dangerous situations. Participation of employees in the risk evaluations and safety inspections, and in making suggestions about improving the safety situation at the workplace, compel them to do the safest possible things as the best strategy [38].

Results found that responsible leadership is significant when the safety consciousness and safety performance relationship is low. The leaders play important roles in shaping safety behaviors (Hypothesis 5). As per the social exchange theory, socially responsible behaviors such as safety behaviors cannot be implemented without the influence of the leaders [30]. The leader's concern to take care of the stakeholders makes a stronger bond to keep closely in touch with the employees. The employees keep in touch with the leaders and share their concerns and problems about safety. The leader guides them and involves them in decision-making and setting the safety parameters. This involvement and the knowledge of the safety practices enhance the consciousness of employees and they become capable of avoiding accidents.

The results show that responsible leadership is a moderator for the safety climate and safety performance relationship (Hypothesis 6). The social exchange theory supports the leader's involvement in shaping the safety climate. The leaders who make people learn and develop a common sense of safety in the organization help people learn and retain the knowledge. This further leads to ensuring safety performance. Based on social identity theory and social exchange theory, this study aims to investigate the mechanisms underlying the responsible leadership, safety consciousness, and safety performance relationship.

Responsibility is one of the essential components of effective leadership in the field of organizational management [83]. Due to a lack of leadership accountability in today's accident-prone climate, businesses are experiencing a crisis of low trust. Lack of trust by employees make them pay less attention to the safety instructions given by their leaders, which leads to mishaps and a loss of health and safety. As a result, executives need to act more responsibly toward employees and other stakeholders. The socially responsible leaders are more effective and have greater impact on the organizations than other leadership styles [84]. As per social identity theory, the people are inclined to categorize themselves

and others into social groups and establish a positive self-concept by identifying with groups that enhance their self-esteem.

Furthermore, individuals tend to boost their self-image by identifying with organizations recognized for their social engagement and responsibility [85], which subsequently motivates employees to strive for organizational safety objectives.

Additionally, people tend to feel better about themselves when they associate with organizations that are known for their social responsibility, such as with a safety climate [85]. This inspires employees to work toward the achievement of organizational safety objectives.

Furthermore, social exchange theory posits that individuals' voluntary actions are motivated by the returns they expect from others [25]; the responsible leaders take care of the stakeholders and in return the employees take care of the leaders and try to oblige them by following the safety standards, thus showing safety performance.


**Preface to "Ocean Noise: From Science to Management"**

This book is a collection of articles relevant to ocean noise and its management. Scientific and societal concern about the effects of underwater sound on marine ecosystems is growing. While iconic megafauna was of initial concern, more and more taxa are being included. Some countries have joined in multi-national initiatives to measure, monitor, and mitigate environmental impacts of ocean noise at large, trans-boundary spatial scales. Approaches to regulating ocean noise change as new scientific evidence becomes available, but may also differ by country.

Articles in this collection cover topics such as ocean soundscapes, sources of underwater sound, anthropogenic sound, sounds made by marine fauna, animal sensitivity to sound, the potential effects of sound on marine fauna, sound propagation under water, sound modelling, noise management, and noise impact mitigation.

The idea for this book was born when we had to cancel the OCEANOISE conference two years in a row, due to Covid. The OCEANOISE conference series has provided a platform for the exchange of scientific results, management approaches, research needs, stakeholder concerns, etc. Attendees have represented various sectors, including academia, offshore industry, defence, NGOs, consultants and government regulators.

> **Michel Andr´e and Christine Erbe** *Editors*


**Abstract**

One of actual global problem is clothes and packing materials biodegradability leading to tremendous water contamination. In order to develop ecologically friendly, game-changing in global industry fabric production, we propose a concept to implement kombucha. Kombucha is a symbiotic bacteria and yeast multispecies consortium producing the most abundant polymer on Earth - bacterial cellulose. There are many advantages of bacterial cellulose that are widely used in medicine, material science, food industry and waste management. Unfortunately: long time of bacterial cellulose polymerisation process, lack of its control, diversity in biological composition, finally, acidic smell and disturbances of kombucha growth - all this issues limit the interest of kombucha use to replace easy-accessible and widely applied synthetic materials. In this chapter will be described a revolutionary concept to develop practical and sustainable use of bacterial cellulose as natural alternative for synthetic materials, particularly for a synthetic fabrics and plastics replacement. The optimal cultivation conditions and examples of bacterial cellulose in applications for daily life will be explained.

**Keywords:** nanocellulose, hydrogel, bio-fabric, design


**9. Examples**

544 Numerical Simulation – From Theory to Industry

1. Guess the velocity field

expression arise for *b*.

**8. Multi-step reaction models**

convergence.

considered.

The revised version Simpler is quite similar to preceding algorithm and was developed

2. Solve the pressure equation, which is similar to pressure correction equation, Eq. 46, to obtain the pressure distribution. In this equation *p'* is replaced by *p* and a different

3. Treating the pressure field as *p\**, solve the momentum equations to obtain *u\*, v\** and *w\*.*

6. Use the velocity field as the guessed distribution and iterate the preceding procedure to

The pressure at any arbitrary point in the computational domain is specified and pressure differentials from this value are computed. The boundary condition may be a given pressure, which makes *p' = 0*, or a given normal velocity which makes the velocity a known quantity at the boundary and not a quality to be corrected so that *p'* at the boundary is not

Models for premixed PM combustion are complicated by the highly nonlinear radiative exchange terms in the energy equation for the solid matrix in addition to the stiffness of the set of gas phase equations. Therefore researchers have simulated the gas phase reactions using single-step chemistry. However, few researchers had taken up this issue and presented multi-step reaction models. It was concluded that use multi-step kinetics is essential for accurate predictions of the temperature distributions, energy release rates, and emissions. Single-step kinetics was shown to be adequate for predicting all the flame characteristics except the emissions for the very lean conditions under which equilibrium favors the more complete combustion process dictated by global chemistry. full mechanism (49 species and 227 elemental reactions), skeletal mechanism (26 species and 77 elemental

In the open literature, there are few articles concerning the interaction between a fuel spray and a PM. The PM under study was of high porosity with uniformly distributed spheres and with uniform distribution of cavities with equal mean pore size in the porous medium. The interaction between droplets during evaporation was neglected. Physical properties of fuel such as latent heat of evaporation and healing value were constant. The temperature distribution inside of the fuel droplet was uniform, but time-varying. Laminar isobaric flow consits of air, fuel droplets, gaseous combustible mixture and hot products of combustion. After evaporation the fuel mixes immediately with air to form a homogeneous combustible mixture. Mass fraction of the liquid was negligible, and the gas was optically transparent. Also, radiative heat transfer between the skeleton surfaces of the porous medium can be

reactions), 4-step reduced mechanism 9 species and 1-step global mechanism.

mainly to improve the rate of convergence. In this case, the mail steps are:

4. Solve the pressure correction equation to obtain *p'*. 5. Correct the velocity field but not the pressure.

needed. For further details, (Patankar, 1980) may be consulted.


**Abstract**

Spherulitic isotactic polypropylenes (iPPs) having a wide range of *β-phase* contents were prepared by adding *β*-nucleators, and the effects of the *β*-phase modification on the mechanical properties of the iPP were investigated. This chapter described the tensile properties of *β*-nucleated iPP, while key structural parameters, such as spherulite size and crystallinity, were controlled. The increase in the *β*-phase content led to broader yield peaks and an enhancement in the yield toughness but to a reduction in the yield strength. On the other hand, the initial elastic modulus was found to be independent of the *β*-contents. Furthermore, the deformation of the *β*-spherulites, which have a sheaflike structure, was anisotropic and depended on the stretching direction with respect to the sheaf axis. Consequently, the improved drawability and ductility of *β*-iPP compared to *α*-iPP are thus associated with the enhanced toughness resulting from the multiple deformation processes in the sheaflike spherulites.

**Keywords:** *β*-phase crystal, mechanical properties, tensile deformation, spherulite, crystalline morphology

## **1. Introduction**

As well-known, isotactic polypropylene (iPP) is a polymorphic material with various crystal forms [1], such as monoclinic (α), hexagonal (β), triclinic (γ), and smectic, of which the *α*-phase is the most typical crystalline form. Commercial grades of iPP usually crystallize into the α-phase with sporadical occurrence of the *β*-phase under higher supercooling [2]. Crystallization under a temperature gradient [3] or flow-induced crystallization [4, 5] encourages the formation of the *β*-phase. To prepare of *β*-modified iPP samples, the introduction of selective *β*-nucleators is the most reliable method [6]. However, unless using specific *β*-nucleating agents, the *β*-phase cannot be obtained at high levels and is always accompanied by *α*-phase crystals. The *α/β* ratio is very sensitive to the crystallization temperature and the cooling rate because of the different nucleation rates of the two crystalline species. Varga et al. [7] found that pure *β*-phase can be achieved in the presence of some selective *β*-nucleators by the selection of appropriate thermal conditions for crystallization. Furthermore, the *β*-phase was found to be transformed to the *α*-phase by heat treatment [8]. This demonstrates that the monoclinic structure is thermodynamically stable, whereas the hexagonal *β*-phase is metastable and difficult to obtain under normal processing conditions.

Recently the number of practical studies has increased [9] because the impact strength and toughness of *β*-nucleated iPP exceed those of *α*-iPP. Although many studies have compared the mechanical properties of *α*-iPP and *β*-iPP, the morphological origin of the differences in the mechanical properties has not been clarified yet.

The mechanical properties of semicrystalline polymers such as iPP and polyethylene (PE) are governed by their morphological features which are specified by several structural variables such as the degree of crystallinity, spherulite size, crystalline thickness, and structural organization of the supermolecular structure [10]. These diversity and independencies of these structural variables make it difficult to provide a molecular or structural interpretation for the mechanical properties and deformation behavior of semicrystalline polymers [10]. Indeed, changing the thermal or processing conditions involves the concomitant modification of several structural parameters; thus, it is difficult to determine the structural origin of the change in mechanical properties as reported by Labour et al. [11]. Consequently, it is necessary to keep all the other structural parameters to be fixed to elucidate the effects of a given structural parameter on the mechanical properties. Very few studies have dealt with the mechanical properties of *β*-nucleated iPP with a wide range of *β*-phase contents, while all the other structural parameters, such as supermolecular organization and crystallinity, are controlled. The aim of this chapter is to elucidate the influence of the *β*-phase modification on the tensile properties of iPP. For this purpose, crystallization procedures, for the production of iPP sheets having a wide range of *β*-phase contents with fixed crystallinity and spherulite size, were developed. In addition, the effects of spherulitic morphology on tensile properties were investigated by comparing the differences in deformation mechanism of isolated α- and *β*-spherulites.

fraction of the iPP. In this chapter, PP0 is denoted by *α*-iPP and PP98 is denoted

*Polypropylene*

The crystalline *β*-phase content (the volume fraction of the *β*-phase in the crystalline portion) was determined from WAXD patterns. The WAXD measurements were carried out at room temperature with a Rigaku RU-200 diffractometer with Ni-filtered Cu-Kα radiation from a generator operated at 40 kV and 100 mA. The *β*-phase fraction in the crystalline part of the specimens was assessed from the ratio of the area of the main (300) *β*-phase to the sum of the areas of the four main crystalline reflections: (110), (040), and (130) from the *α*-phase plus (300) from

Here, we modified the analysis method proposed by Somani et al. [13] to obtain the volume fraction of *β*-phase in the crystalline fraction quantitatively. The reflection peaks in the WAXD profiles were deconvoluted. In the WAXD profile, (110) at 14.1°, (040) at 16.9°, and (130) at 18.5° are the principal reflections (in 2*θ*) of the *α*-phase crystals of iPP, whereas (300) at 16.1° is the principal reflection of *β*-phase crystals, and are considered as the markers for *α*-phase and *β*-phase crystals, respectively. The various reflection areas were computed after subtraction of the

The volume fraction of *β*-phase crystals was calculated using the following

*ϕβ* ¼ *Sβ*ð Þ 300 *ρ*�1

*Sβ*ð Þ 300 *ρ*�1

of the (300) reflection peak, and *Sα* is the sum of the areas of (110), (040), and (130) peaks of *α*-phase crystals, respectively. The calibration constant *k* was estimated to be 1.11 from the difference in the sensitivity of WAXD reflections with respect to the thickness of the sheets for the *α*-phase and *β*-phase reflections.

Crystallinity can be precisely determined from density data. The densities of the specimens were determined by the flotation method. A binary medium prepared from various ratios of distilled water and ethanol was used. The volume crystallinity

> *χV* ¼ *ρ* � *ρa ρc* � *ρa*

*βc*

*βc* þ *kSαρ*�1 *αc*

*Sα* ¼ *Sα*ð Þ 110 þ *Sα*ð Þ 040 þ *Sα*ð Þ 130 (2)

) is the density of *α*-phase crystal [17], *Sβ* is the area

) is the density of the *β*-phase

(1)

(3)

the *β*-phase using Turner-Jones method [12].

*β-Modified*

*http://dx.doi.org/10.5772/intechopen.83348*

 *Isotactic*

Here *k* is the calibration factor, *ρβc* (=921 kgm�3

crystal [14–16], *ραc (*=936 kgm�3

can be obtained using

**73**

by *β*-iPP.

*Characteristics of iPP sheets.*

*Tensile Properties in*

*DOI:*

**Table 1.**

amorphous halo.

equations:

and