*3.5. Isoelectric Focussing*

Analytical isoelectric focusing polyacrylamide gel electrophoresis was performed on a HPETM BlueHorizonTM system (Serva Electrophoresis GmbH, Heidelberg, Germany) using ServalytTM PrecotesTM Precast Gels (Serva Electrophoresis GmbH) with an immobilized pH gradient of pH 3 to 10. To determine the isoelectric points of the enzymes, marker proteins (IEF-Marker 3-10, Serva Electrophoresis GmbH) were used. Gels were stained with Coomassie Brilliant Blue, or for specific visualization of peroxidases, with 1% (*w*/*v*; 9.2 mM) phenylendiamine and 1% (*w*/*v*; 10.6 mM) urea peroxide (dissolved in 100 mM sodium acetate buffer pH 3.5) at RT until a yellow band was observed.


**4. Casting and Mechanical Testing**

The preparation of a mold requires a pattern which is an exact replica of the part to be cast. A wooden pattern of the optimized casting layout is developed as shown in Figure 10a to compact sand around it thereby forming a mold. The resulting sand mold

is shown in Figure 10b. In order to avoid direct interaction of molten metal with the mold material, a dense layer of zirconium-based coating is applied to the mold surface. Mold properties evaluation revealed a compression strength of 18 kg/cm2 and a scratch hardness of 28–29. The pouring temperature is set to 1590–1600 ◦C for which steel is melted in an induction furnace which offers ease of operation, high quality of products, better metallurgical functions, and lower oxidation losses. The steel is deoxidized using Aluminum in the ladle prior to pouring into the mold. It is ensured to perform casting at similar conditions which are used in the simulations. Figure 10c shows the entire casting just after the removal of mold. As mentioned earlier, the specimens are considered as simple cast parts which are obtained after removing pouring basin, sprue, runner bar, and risers. The specimens are then annealed at 920 ◦C, held for half an hour, and cooled in furnace. Specimens after heat treatment are machined to final dimensions as per the ASTM E-466 standard [14]. The quality and surface finish of the specimens is enhanced during machining.

**Figure 10.** (**a**) Pattern, (**b**) Sand mold and (**c**) Cast Specimens prior to cleaning and finishing.

The quality of cast specimens is evaluated using radiographic examination. The results of X-ray imaging are presented in Figure 11. Some porosity is revealed within the test section of specimens which is observed as difference in appearance of grips and the test section as shown in Figure 11. However, the distribution of porosity from one specimen to another is not much different.

**Figure 11.** X-ray imaging of steel fatigue specimens.

The fatigue testing is done as per the ASTM E-466 standard [14]. The experimental setup is presented in Figure 12. Fully revered conditions where R = −1 is used to test all specimens under cyclic loading. The frequency of testing is set to be 5 Hz for all specimens. Fatigue testing is done until fracture for all specimens except for runout condition which is 106 cycles in this study. A careful selection of stress amplitude has led to the testing of six specimens for finite life and one for the infinite life. Table 3 lists the stress amplitude selected and number of cycles to failure for each specimen. Figure 13 depicts the SN curve developed as a results of fatigue testing of steel specimens.

**Figure 12.** Experimental setup for fatigue testing.

**Table 3.** Experimental results for fatigue testing of specimens.

**Figure 13.** S-N curve for cast steel specimens.


**8. Conclusion**

In this chapter it has been argued that a key problem in sociology, as in any science, is that sociologists are all too often unaware of the ambivalence of their theorizations of society since they all too often fail to take into account the ambiguity inherent to social existence. In this sense, scientific activities can fail to fulfil their promise of enlightenment, that is, the promise of the liberation from ignorance, and instead reinforce ideologies, sociology's mortal enemy; as well as the enemy of genuine innovation, renewal and revitalization. The deliberate or unconscious ignorance of ambiguity leads to the imposition of models of society on social existence, through bureaucratic implementations and enforcements. In order to develop a truthful sociology or genuine scientific knowledge, that is, one that is true to its own promise, scientific processes such as enquiry, argumentation, clarification and reflection cannot be separated from a broad erudition, empathic understanding and sociological wisdom; only then can sociology be kept out of bureaucratic structures of organizations, in which ambivalence and ambiguity are denied. Instead it must promote dialogue, both within science and within the organizations of society at large, as the appropriate social form for doing sociology. It is the only form that prevents sociologists from alienating themselves from social life, and consequently, from contributing towards reification.

Only through dialoguing is it possible to develop degrees of reflexivity, and to keep theory or theorizing about society, and practice or the social consequences of theory together. Only through dialoguing can sociology manifest, and realize its commitment to the European values of Socratic reason and freedom. At the same time, this commitment is a sine qua non if sociology is not to become the handmaid of power holders; and used as a lethal instrument for manipulating (rationalizing) social existence and for promoting some ideological form of existence in states, corporations, civil society, families, and so forth (like promoting a neo-liberal way of living). In his call for strengthening what he calls 'public sociology', Michael Burawoy (2005a) has ardently voiced the need to reconcile the different sociologies in new sociologies needed for new worlds. Burawoy stresses the urgent need for sociology's presence in the publics, in particular in protest movements that organize themselves to resist neo-liberalized bureaucracies. And indeed, in global capitalist worlds, as contrasted with the more democratic worlds, the social foundations or preconditions for being and doing sociology, and for generating reflexivity, are shaky; universities, in such contexts, tend to become dependent on, and inseparable from, ideological entities. Such entities create their own priorities in which the public mission of representing and realizing both Socratic reason and freedom of action is ignored. The European values are, as always, at risk in social existence, and sociologists face a tough battle to contribute towards the creation of reflexivity, the intellectual sensibility behind theory and practice, so much needed to defeat ideologies and live up to the promise of sociology.


**4. The influence of regional anesthesia for stress surgery response**

The choice of anesthesia type as well as technique relates to influence on the immune response and may be important in patients with immunological disorders. This situation occurs in patients with immune system deficiency. Patients suffer from immune system disturbances, due to autoimmune or cancer diseases, appear to require special consideration. Among this group of patients should be expected the pathological reaction of immune system or significant immunosupression caused by the surgery trauma.

The imbalanced immune system can modulate the neuroendocrine system and inflammatory responses to the surgery trauma in terms of production of cytokines, immunoglobins, proliferation of lymphocytes, and phagocytosis monocytes/macrophages. The choice of regional anesthesia techniques allow to avoid the supply of volatile/ intravenous anesthetics agents and the controlled ventilation procedures. Furthermore , the afferent nerves blockade is associated with attenuation of the hormonal response to the surgery stress. The regional anesthesia techniques have a significant effect on the immune

The Stress Response and Its Functional Implications in the Immune

consequences for immune responses.

of cancer (Bar- Yosef et al., 2001; Wada et al., 2007).

al., 1998).

Response After Surgery in Patients with Chronic Inflammation Undergoing Arthroplasty 23

neutrophil activity in patients with the spinal anesthesia compare to general anesthesia. The Th1/T2 (CD4+ T/ CD8+ T) balance is necessary for the immune response - both the humoral and the cell-mediated. The Th1 cells produce the interferon gamma and are responsible for the cell-mediated immunity. The Th2 cells produce interleukin-4 and are more effective in inducing the humoral immunity. Cytokine concentration is altered during the surgery as well as anesthesia, which may effects the Th cell predominance with

The advances in the knowledge on the T helper 1 (Th1) and T helper 2 (Th2) cells revealed that the Th1 cells produce cytokines that stimulate the proliferation of CTLs while Th2 cells produce cytokines that are responsible for the activation of the humoral immune response in healthy people. The use of regional anesthesia allows the weakening of the immunosuppression caused by the operational trauma, which is evidenced by studies demonstrating a greater proportion of the Th1 to Th2 and increased neutrophils activity in patients received spinal anesthesia (Erskine et al., 1992; Erskine et al., 1994; Le-Cras et

It has also been demonstrated the beneficial effect of the spinal anesthesia on the immune system regards with its activity and the relationship with the incidence of cancer metastasis. Compared with the general anesthesia using volatile agents, the spinal anesthesia caused significantly less immunosuppressive effects with less postoperative incidences of metastasis in patients underwent surgery. That confirms the beneficial effects of the regional anesthesia on the immune system and the relationship between its activity and the incidence

**5. The stress response and its functional implications in the immune**

surgery was evaluated in the patients with the different disease activity.

spinal anesthesia. Hyperbaric bupivacaine in dose 4 mg was used in all cases.

**5.1 Material and methods**

Patients:

**response after surgery in patients with chronic inflammation (clinical study)**  The connection between the surgery stress and the immune system has been presented in numerous publications and while many aspects of the subject have been discussed, most research has been devoted mainly to patients whose immune system works properly. In the available literature there is little information on the impact of the surgery stress on the immune system in patients with a chronic inflammation which in the light of the accepted hypothesis should contribute to the modulation of the immune system response to the surgery stress. Therefore it can be assumed that the development of the stress surgery response should be altered by abnormalities of immune system associated with chronic inflammation. The previous results had reported by author et al. partially helped to confirm the chronic inflammatory state ability to modify of the response of the immune system to surgery trauma (Lisowska et al., 2008). In view of the fact that many of earlier evaluated patients presented significant advanced chronic inflammatory process that reflected in the high activity disease being evaluated the Disease Activity Score-28 (DAS28) based European League Against Rheumatism (EULAR) response criteria (Fransen & van Riel, 2009). DAS28 seems to be correlated with severity of inflammation; therefore, the immune response to

The 37 patients with long term rheumatoid arthritis scheduled for knee arthroplasty under

system which depends on both the nerve blockade and the administrated local anesthetic drugs (Lisowska, 2008).

The results of study revealed the influence of the bupivacaine presence for the reduction of the synthesis of immunoglobin IgG, IgM, IgA and enhancing the granulocytes phagocytosis. The epidural anesthesia with bupivacaine was associated with lower serum concentration of gammaglobulins (IgG, IgM, IgA) and the complement components C3 and C4 (Gajdosz, 1994).

Bupivacaine is the most popular, long acting local anesthetic with a wide range of administration for peripheral and central nerves blockades. Ropivacaine is also a long acting local anesthetic drug similar to bupivacaine in terms of pharmacological activity, but in contrast to is characterized by the lower cardiotoxity. Lidocaine is the most often and widely used local anesthetic for the peripheral nerves blockades especially in the combination with the bupivacaine for more beneficial balance of duration and onset. Lidocaine is also classified as an anti-arrhythmic agent. Bupivacaine in comparison with the lidocaine shows more potent effect on the function of leukocytes. However, the ropivacaine has been shown its anti-inflammatory properties related to the inhibition of leukocyte function such as the rolling/ adhesion which accompanies the early stage of the local inflammatory response. Moreover, both the ropivacaine and lidocaine could inhibit the CD11b/CD18 up-regulation and the L-selectin down-regulation on neutrophils migration between endothelial cells. There has been found that the effect of the lidocaine was 2.5 times lower than the ropivacaine (Martinsson et al., 1997; Zhang et al., 2000).

The extent of nerves blockade, occurs due to regional anesthesia, appears to have an influence on the neuro-endo-immune response intensity. The endocrine - metabolic stimulation following the surgical procedure can be inhibited by the afferent nerves blockade. The blockade of motor, sensory and afferent sympathetic fibers leads to resulted in predominance of parasympathetic system resulting changes in circulation The intensified circulation may reduce the release of cytokines associated with the tissue ischemia and hypoxia but from the other site a marked low perfusion triggers cytokines burs following hypoxia. The degree of blood flow distribution is directly related to the level of the blockade. It was shown that usage of continuous epidural anesthesia reduced the hormonal stress response and improved the protein metabolism, but it didn't play any significant role in the stimulation of inflammatory response *(*Kehler, 2000*).* Although in comparison with general anesthesia, the epidural anesthesia demonstrate less effect on the activity of natural killer cell (NK), T and B cells (Tonnesen et al., 1988).

The spinal anesthesia is considered as the standard procedure for the orthopedic surgery. The choice of the central blockade is influenced with many benefits such as reduced risk of the postoperative cardiovascular, pulmonary and thromboembolic complications. The prolonged analgesia which spreads onto post operative period is also worth to be emphasized. The patients who underwent surgery with the spinal anesthesia would require greatly less opioids which action is not neutral to the immune system. Further advantages of the regional anesthesia, especially in the RA patients, has ability to avoid the difficult and traumatic intubation. The majority of patients with advanced RA demonstrated the atlanto-axial instability with the great risk of spinal cord compression (Lisowska et al., Jan 2007; 2008).

Many studies have revealed that the regional anesthesia can attenuate the perioperative immunosuppression related to the stress surgery. There are evidences demonstrating a greater number of the Th1 compare to Th2 (CD4+ T and CD8+ T cells) and increased the neutrophil activity in patients with the spinal anesthesia compare to general anesthesia. The Th1/T2 (CD4+ T/ CD8+ T) balance is necessary for the immune response - both the humoral and the cell-mediated. The Th1 cells produce the interferon gamma and are responsible for the cell-mediated immunity. The Th2 cells produce interleukin-4 and are more effective in inducing the humoral immunity. Cytokine concentration is altered during the surgery as well as anesthesia, which may effects the Th cell predominance with consequences for immune responses.

The advances in the knowledge on the T helper 1 (Th1) and T helper 2 (Th2) cells revealed that the Th1 cells produce cytokines that stimulate the proliferation of CTLs while Th2 cells produce cytokines that are responsible for the activation of the humoral immune response in healthy people. The use of regional anesthesia allows the weakening of the immunosuppression caused by the operational trauma, which is evidenced by studies demonstrating a greater proportion of the Th1 to Th2 and increased neutrophils activity in patients received spinal anesthesia (Erskine et al., 1992; Erskine et al., 1994; Le-Cras et al., 1998).

It has also been demonstrated the beneficial effect of the spinal anesthesia on the immune system regards with its activity and the relationship with the incidence of cancer metastasis. Compared with the general anesthesia using volatile agents, the spinal anesthesia caused significantly less immunosuppressive effects with less postoperative incidences of metastasis in patients underwent surgery. That confirms the beneficial effects of the regional anesthesia on the immune system and the relationship between its activity and the incidence of cancer (Bar- Yosef et al., 2001; Wada et al., 2007).


*Article* **Obsolete or Viable? Revision of Lane-Change Manoeuvre Duration Empirical Calculation**

**Roman Mikulec \*, Marek Semela, Albert Bradác, Stanislav Tokaˇ ˇ r, Martin Bilík, Michal Kˇrižák, Michal Belák, Robert Kledus, Andrej Haring and Vlastimil Rábek**

> Institute of Forensic Engineering, Brno University of Technology, Purkynova 464/118, 612 00 Brno, Czech Republic<EMAIL_ADDRESS>(M.S<EMAIL_ADDRESS>(A.B<EMAIL_ADDRESS>(S.T<EMAIL_ADDRESS>(M.B<EMAIL_ADDRESS>(M.K<EMAIL_ADDRESS>(M.B<EMAIL_ADDRESS>(R.K<EMAIL_ADDRESS>(A.H<EMAIL_ADDRESS>(V.R.)

**\*** Correspondence<EMAIL_ADDRESS>
**Abstract:** This study presents a calculation of the time required to execute a lane-change manoeuvre. Compared with other (and older) calculation methods, an analysis was conducted to determine which approach could yield the most reliable results. This study aimed to present a universal calculation method for different road surfaces, surface conditions (dry and wet road surface), and vehicle types (i.e., from small vehicles to SUVs). A total of 108 comparable manoeuvres with modern vehicles were used as a basis for statistical analysis. A new mathematical constant was found based on a regression analysis, adjusting one of the older calculation methods (so-called Kovaˇrík equation), providing the best match between real and calculated manoeuvre duration.

**Keywords:** lane change; manoeuvre duration; empirical calculation; vehicle stability; lateral acceleration

### **1. Introduction**

A lane-change manoeuvre is part of a day-to-day commute. However, if the manoeuvre is part of a crash scenario (either in the form of crash avoidance or if the crash happened during or before the manoeuvre execution), it is necessary to determine when and where the manoeuvre began to place it in the crash scenario timeline.

Although the pre-crash analysis could be done using EDR data currently, older vehicle models usually do not possess these data, which can be problematic considering the average age of personal vehicles in the Czech Republic exceeds 15 years. Furthermore, vehicle manufacturers in Europe are not yet required to provide access to EDR data. Therefore, a calculation of the time needed to execute the avoidance manoeuvre by other methods is necessary.

Analysis of vehicle lateral movement during lane change, overtaking, or crash avoidance presents a problem in traffic accident reconstruction. The lane-change manoeuvre is not used as often as braking for crash avoidance [1,2] (the mechanism of the manoeuvre is more complex compared to braking), and there is usually less evidence left by the vehicle used to identify the vehicle's trajectory (such as yaw or skid marks). If a vehicle crash occurs on a wet road surface, a crash investigator must consider lowered adhesion while analyzing vehicle dynamics. Lane-change alteration by vehicle's adaptive cruise control was explored in [3]. As for the driving conditions, weather is one of the most common factors changing road surface conditions, especially rain, lowering tyre traction (adhesion) due to wet road surface [4].

While modern accident reconstruction methods utilize various simulation programs with integrated mathematical models, there is no guarantee that the result reflects reality. There are several unknown input parameters (delay of the steering mechanism, steering speed, driver model, and others). Therefore, using an empirical calculation based on actual manoeuvre analysis data or the simulation basis seems to be a prudent approach.

**Citation:** Mikulec, R.; Semela, M.; Bradáˇc, A.; Tokaˇr, S.; Bilík, M.; Kˇrižák, M.; Belák, M.; Kledus, R.; Haring, A.; Rábek, V. Obsolete or Viable? Revision of Lane-Change Manoeuvre Duration Empirical Calculation. *Energies* **2021**, *14*, 8439. https:// doi.org/10.3390/en14248439

Academic Editors: Guzek Marek, Rafał Jurecki and Wojciech Wach

Received: 7 November 2021 Accepted: 10 December 2021 Published: 14 December 2021

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

**Copyright:** © 2021 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/).


**Appendix A. Patient-Wise Evaluations**

*Appendix A.1. Dice Coefficients at Different Levels of Deformation*

**Figure A1.** (**a**–**h**) Dice coefficients at different levels of deformation from patient 1 to patient 8.

**Figure A2.** (**a**–**h**) Average distances between target model and deformed models for Patients 1–8, respectively.

*Appendix A.3. Dice Coefficients for Different Methods*

**Figure A3.** (**a**–**h**) Dice coefficients between target model and deformed models for the different cardiac phases.

*Appendix A.4. Average Distances for Different Methods*

**Figure A4.** (**a**–**h**) Average distances between target model and deformed models for the different cardiac phases.

*Appendix A.5. Dice Coefficients for Different Phase Sampling Methods*

**Figure A5.** (**a**–**h**) Dice coefficients between target model and deformed models for the different cardiac phases.

**Figure A6.** (**a**–**h**) Average distances between target model and deformed models for the different cardiac phases.


*4.1.  It was also revealed that more than half of the communities adhere to the rules on garbage sorting, and had installed garbage bins for separate disposal. Nonetheless, the proportion of respondents who consistently or almost frequently sort their garbage at home before discarding is less than 40%. Roughly 40% of the respondents revealed that they separately discard garbage at the collection spot. Among them, 55.6% confirmed that they are intellectually equipped with the correct knowledge of garbage sorting. In contrast, about 40% of the respondents were found to sort garbage based on incorrect knowledge (see Figure 3).

**Figure 3.** Behavior related to sorting household garbage. Source: authors' own calculations, 2020.

With respect to the garbage sorting program, 60% of the respondents asserted that they support it, 20% asserted that they somewhat support it, and only 1% opposed it. However, the proportion of respondents who agree or slightly agree to comply with the refuse charge system is 40% (see Figure 4). In other words, although 60% of the respondents are highly supportive of the garbage sorting program, an equal number (60%) of them are indi fferent to the refuse charge system.

**Figure 4.** Receptiveness to the refuse charge system. Source: authors' own calculations, 2020.

The survey also inquired into the environmental and moral value judgements of the respondents in relation to a 16-item scale of pro-environmental behavior and a nine-item scale of altruism (see Table 3). In creating the pro-environmental behavior scale, this study took its clues from a study by Zhao et al., and used a new approach that produces an accurate and reliable measurement based on the separate analysis of three aspects of pro-environmental behavior: purchase, use, and reuse [31].

**Table 3.** Pro-environmental behavior scale items.

Source: Authors' own calculations, 2020. Notes: SA is 'strongly agree', SWA is 'somewhat agree', U is 'unsure', SWD is 'somewhat disagree', SD is 'strongly disagree', ri-t is the item-total correlations, α is Cronbach's coe fficient alpha, and FL is factor loading. Percentages may not sum to 100 due to rounding.

The altruism scale was constructed as a new scale for this research. We applied the Schwartz norm-activation principles to measure altruistic attitudes (see Table 4). According to Schwartz's model, altruistic behavior arises from personal norms if two criteria are met: an individual must be aware that particular actions (or inactions) have consequences for the welfare of others (awareness of consequences, AC), and an individual must ascribe responsibility for the consequences of those actions to himself or herself (ascription of responsibility, AR) [32,33]. The simultaneous presence of AC and AR in a specific situation enables pertinent personal norms to motivate behavior.

**Table 4.** Altruism scale items.

Source: Authors' own calculations, 2020. Notes: SA is 'strongly agree', SWA is 'somewhat agree', U is 'unsure', SWD is 'somewhat disagree', SD is 'strongly disagree', ri-t is item-total correlations, α is Cronbach's coefficient alpha, and FL is factor loading. Percentages may not sum to 100 due to rounding.

Durkheim provided an eloquent analysis of the importance of moral norms in influencing human collective behavior [34]. Personal norms are perceived moral norms that represent personal beliefs about what is right and wrong when acting in a particular manner in a specific situation. Moral norms are a shared set of beliefs, values, and ideas on what is presumed to be the right behavior. They regulate social life or human affairs by guiding and restraining individual behavior and action that produces adverse consequences for other members of society. Thøgerson [35] discussed the role of social norms in restricting individualism in favor of collectivism; in 2009, Thøgerson [36] further explored the strength of a person's norms—namely, subjective social norms and personal norms—in guiding environmentally responsible behavior. Personal norms or moral norms inform our sense of identity and behavior. They represent the will of individuals to altruistically prioritize collective interest over self-interest.

The research presented here applies Schwartz's principles in the form of a general altruism scale based on Clark et al. [22]. The scale contains a total of nine items that test for the presence of individual personal norms, AC, and AR. Specific items are listed in Table 4. Items 1, 3, and 4 refer to personal norms; Items 2, 5, and 8 represent AC; and Items 6, 7, and 9 represent AR.

For the altruism scale, Cronbach's coefficient alpha was used to evaluate internal consistency. When all of the nine items were used, Cronbach's coefficient alpha was found to be 0.434. Given this, the items with higher values (namely, Items 3, 6, and 8) were eliminated from the analysis.

This study used a discrete choice model for the analysis. The objective variables considered are end-point garbage sorting behavior ('sorting behavior'), receptiveness to a refuse charge system ('receptiveness to fees'), and receptiveness to policies requiring garbage sorting ('receptiveness to policies'). The values of the garbage sorting behavior variable, an objective variable, were computed based on the responses derived from the questionnaires.  In answering the question,

the respondents are required to choose one of the five response options: always, very frequently, occasionally, rarely, and never. A five-point Likert scale was used to assign values to the responses (5 = always, ... , 1 = never). The variable 'receptiveness to fees' corresponds to the question, "Do you support the idea that people discarding more garbage should be charged a higher fee?"  For these questions, the respondents were required to select one of the five response options: strongly agree, somewhat agree, unsure, somewhat disagree, or strongly disagree. Again, a five-point Likert scale was used to assign values to the responses as stated (5 = strongly agree, ... , 1 = strongly disagree).

As shown in Table 5, the explanatory variables include: (1) *EI* (Knowledgeable or not knowledgeable ('Agree or not agree' in Shenyang) of the local economic incentive program: yes = 1, no = 0), (2) *PEB* (the score of the pro-environmental behavior scale), (3) *ALT* (the score of the altruism scale), (4) *OWNERSHIP* (have or do not have a residential ownership: yes = 1, no = 0), (5) *MANAGEMENT* (the communities have or do not have a property management: yes = 1, no = 0), (6) *RULE* (the communities have or do not have the rules on garbage sorting: yes = 1, no = 0), (7) *INFRA* (the communities have or do not have the infrastructure to support garbage sorting: yes = 1, no = 0), (8) *DIST* (distance to the garbage collection spot: 5 = more than or equal to 10 min, 4 = 7–9 min, 3 = 4–6 min, 2 = 1–3 min, 1 = less than 1 min), (9) *KNOWLEDGE* (knowledge on the city's household garbage sorting regulations, derived from the answers to the question: 5 = very familiar, 4 = familiar, 3 = have heard about, but not familiar, 2 = never heard about the regulations, but have heard about the sorting instructions, 1 = never heard about the regulations or the sorting instructions), and (10) demographic variables including *GENDER* (male = 1, female = 2), *AGE* (above 60 = 5, 50–59 = 4, 40–49 = 3, 30–39 = 2, 18–29 = 1)*, MARRIAGE* (marital status, yes = 1, no = 0), *REGIS* (household registration status, native = 1, outsiders = 0), *EDUCATION* (education level: postgraduate or above = 4, undergraduate or junior college = 3, senior high or senior secondary = 2, junior high and below = 1), *OCCUPATION* (yes = 1, no = 0), *INCOME* (above 4001\$ = 8, 3001–4000\$ = 7, 2501–3000\$ = 6, 2001–2500\$ = 5, 1501–2000\$ = 4, 1001–1500\$ = 3, 501–1000\$ = 2, less than 500\$ = 1), *POLITICAL* (political affiliation, member of the CPC = 4, the Communist Youth League = 3, non-communist or minor parties = 2, commoner or others = 1), and *CITY* (Shanghai = 1, Shenyang = 2, Chengdu = 3).

**Table 5.** Description of the explanatory variables.

**Table 5.** *Cont*.

Source: authors' own calculations, 2020. Note: N = 1621, SD: Standard deviation, SD/%: this column refers to the standard deviation (SD) unless otherwise noted (%).

### *4.2. Estimation Results*

The results of the analysis are shown in Tables 6 and 7. Table 6 shows the estimation results for all of the respondents. The estimated coefficients on *PEB* and *EI* are statistically significant in the expected direction. More specifically, the positive signs on both variables indicate that the stronger the environmentally friendly activities and knowledge are, the higher the probabilities of participating in the garbage sorting program, the receptiveness to fees, and the receptiveness to policies are. The result supports the idea that economic measures exert a positive impact on inducing and promoting residents' garbage sorting behavior. They also serve to increase their receptiveness to the introduction of a refuse charge program, or to policies mandating garbage sorting. Nonetheless, the altruism scale (ALT) only has a significant positive correlation with receptiveness to policies. This indicates that altruistic individuals will engage in pro-environmental behaviors when there are environmental benefits. However, when it comes to private benefits, various responses were noted. For instance, in response to the question of "What charging method do you think is appropriate if the government introduces quantity-based charging for garbage collection?", 416 respondents (the largest number) chose a designated bag system (Figure 5).

Source: authors' own calculations, 2020. Note: the symbols \*, \*\*, and \*\*\* indicate significance at the 10%, 5%, and 1% levels, respectively.

**Figure 5.** The refuse charge system. Source: authors' own calculations, 2020.

However, in response to the further question of "How much are you willing to pay if a designated bag system is introduced?", approximately 60% of the respondents indicated 0.01 to 0.02 yuan, which is, by any standard, surprisingly low (Figure 6). Implicitly, even though some respondents revealed that they support a refuse charge system, they are egoistically unwilling to bear any financial burden. This contradicts Schwartz's principles of altruism, in that the awareness of consequences (AC) did not lead to the ascription of responsibility. In other words, these respondents displayed a high self-interest, and are unwilling to engage in pro-environmental behavior or action in the presence of a perceived cost of sacrifice, as expressed in terms of a financial burden.

**Figure 6.** WTP (Willingness to Pay) for waste collection. Source: authors' own calculations, 2020.

The signs and coefficients for *AGE* indicate that the elderly are more likely to participate in the garbage sorting program, and display a higher receptiveness to fees. One reason for these tendencies could be that the young workers are unable to freely join sorting efforts that are scheduled during specific hours in the morning and evening in areas where the separate collection and disposal of HSW is implemented. There is also an asymmetric information issue. It may well be that campaigns to advertise the Green Account, the Green Earth program, the refuse charge system, and policies related to garbage sorting are mostly held during the daytime, with the consequence that the information fails to reach young workers. This may be one of the main factors that impede the wider recognition and adoption of sustainable HSW programs and policies or refuse charge systems among the younger population.

*GENDER* positively correlates with receptiveness to fees. That is, males were shown to be more likely to support a refuse charge system. The signs and significance of *OCCUPATION* indicate that people who have a stable job are more likely to become 'willing' participants. This may be attributed to the fact that businesses are more effective and quicker at educating employees on policies requiring garbage sorting and actual waste sorting. However, *OCCUPATION* does not have an effect on the receptiveness to fees and the receptiveness to policies. The signs and significance of *INCOME* show that the higher an income is, the higher the willingness to pay the refuse charge is.

Furthermore, the coefficients for *MARRIAGE* and *OWNERSHIP* are not significantly deviated from zero, indicating that neither affects the probability of participation, receptiveness to fees, or receptiveness to policies. The estimated coefficients on *EDUCATION* were found to be statistically significant in the negative direction of the garbage sorting behavior; that is, the higher a person's education level is, the less likely he or she will be willing to engage in garbage sorting. This result contradicts existing studies.

One the main reasons behind the above contradicting trend is that people with higher education levels tend to work longer. Hence, if sorted garbage is scheduled to be collected during specific hours in the morning and evening, as mentioned above, these people, in most cases, are not able to participate in HSW separation and collection. The signs and significance of *REGIS* indicate that the 'outsiders', who do not have a household registration for their area of residence, are more likely to be willing participants. They also displayed a higher receptiveness to policies. This result is in contrast to what was expected before the estimation. One of the main contributing factors behind this deviation is probably due to the 'sense of place' psychological factor of the 'outsiders', which leads to an increase of their feeling of identification, and to a positive change in their strength of relationship with the environment within which they exist. Choy [23,24] empirically established a strong relationship between the indigenous peoples' close attachment to the natural environment (sense of place) and their strong altruistic inclination for environmental protection, based on field research conducted in the tropical forest in Borneo, Malaysia. Choy [25] examined the values that the forest-dwelling indigenous people placed on the forested environment that they called home. He classified this as a 'sense of place' value. Semken [37] provides a good discussion of the strong sense of place of the American Indian and Alaskan Native people.

*POLITICAL* has a significantly positive correlation with behavior and receptiveness to policies, although its magnitude is small. It seems that members of the CPC display not only a stronger environmental awareness, but also a higher receptiveness to policies than the general public at large. One reason behind this pro-environmental inclination could be that, in the garbage separation pilot area, Primary Party organizations also play a key role in garbage sorting, and members of the CPC have acquired a green habit of actively taking part in garbage sorting [38,39]. This spontaneously sets an example to inspire and induce their neighbors and relatives to adopt environmentally friendly practices by introspection. This result also supports existing studies, such as Ghorbani et al. [21].

For matters governing the disposal of the sorted household garbage, the estimated coe fficients on *RULE* imply that communities which establish garbage sorting rules are more likely to participate in a garbage sorting program. They also revealed a higher receptiveness to waste management policies. However, as regards *INFRA*, the existence of proper equipment at the garbage collection spot significantly and positively impacts garbage sorting behavior. The signs and coe fficients for *MANAGEMENT* indicate that communities with a property management company show a higher level of receptiveness to policies. More specifically, in a community with a property management company, the company undertakes the task of sorting the garbage on behalf of the residents. This reduces the burdens of the residents. Inexorably, this tends to induce a moral sense of obligation incumbent upon the residents to react positively to policies requiring garbage sorting. The coe fficients for *DIST* show that the more time required to arrive at the collection spot, the less receptive the individuals are to policies requiring garbage sorting.

Additionally, the estimated coe fficients on *CITY* statistically, significantly, and positively correlate with the receptiveness to fees and to policies. This implies that there are di fferences in receptiveness to fee and policy support among cities.

The estimation results for the respondents who perform end-point sorting are shown in Table 7. The results of the estimation are similar to those of the case with all of the respondents. However, the coe fficients for *MANAGEMENT*, *DIST*, *MARRIAGE*, and *POLITICAL* are not significantly correlated with the objective variables, indicating that none of them a ffect the probability of participation, receptiveness to fees, or receptiveness to policies.

The signs and significance of *INCOME* show that people with a higher income are more likely to take part in garbage sorting. *OCCUPATION* is also significantly and positively correlated with the receptiveness to policies. It seems that because businesses are quick to educate employees on policies requiring garbage sorting and actual sorting wastes, they have contributed to the enhancement of individuals' receptiveness to such policies. The estimated coe fficients on *AGE* are not statistically significant with respect to sorting behavior and the receptiveness to policies. On the other hand, *RULE* and *INFRA* have a significantly positive correlation with garbage sorting behavior. The estimated coe fficients on *KNOWLEDGE* were found to be statistically, significantly, and positively correlated with garbage sorting behavior, the receptiveness to fees, and the receptiveness to policies. It seems that the knowledge of the city's household garbage sorting regulations stimulates people to participate in the garbage sorting program. This has the e ffect of boosting their receptiveness to fees.

The estimation results show that garbage sorting behavior, the receptiveness to fees, and the receptiveness to policies significantly vary across the three cities. An analysis with propensity score matching was also performed. The receptiveness to fees and the receptiveness to policies were set as outcomes, the existence of economic incentives was set as an assignment variable, and the respondents' attributes were set as covariates. All of the coe fficients were negative. In other words, compared with the residents in Shanghai and Chengdu, where economic incentive measures such as the Green Account and the Green Earth program have been introduced, the residents of Shenyang, where such measures are non-existent, were found to engage more actively in garbage sorting. They are also more receptive to a refuse charge system and policies requiring garbage sorting.

Source: authors' own calculations, 2020. Note: the symbols \*, \*\*, and \*\*\* indicate significance at the 10%, 5%, and 1% levels, respectively.

### *4.3. Overall Estimate Outcomes and Policy Implications*

All of the study areas clearly show that many factors influence residents' sustainable waste disposal behavior and practice. These may be widely divided into the following categories:

Furthermore, the analysis based on the external variables indicates that the participants of the garbage sorting program tend to live in communities that have clear rules on garbage sorting and have installed the proper equipment at garbage collection spots. Additionally, the development of the solid waste management infrastructure—such as smart garbage collecting stations that are designed to recognize different types of waste automatically—can encourage citizens to cooperate with the local government in waste sorting.

The analysis also uncovered the interesting fact that participants of the garbage sorting program tend to be elderly and employed. In addition, the study revealed a lesser known, let alone well-analyzed, issue that the 'sense of place' can serve as a crucially important intrinsic impact factor in inducing an individual's green behavioral practices.

Our investigation also uncovered the important fact that the power of the external influence arising from politically influential and environmentally inclined elites, such as CPC members, is positively related to the state of green environmental consciousness or the green mentality of the individuals surrounding them. These findings reflect the combined significance of external and internal moderations, and the importance of advertising and educational activities with respect to the garbage sorting policies in each community. In the future, the local government could optimize the use of metro or subway advertising media or social media such as WeChat or Tiktok in order to disseminate information concerning sustainable waste disposal practices. These critical measures also serve to induce communities to strengthen their waste sorting rules and set up their waste collection spots properly.

Our study further revealed that residents' receptiveness to a refuse charge system varies across cities, and many respondents tend to oppose the implementation of a refuse charge program. It was also found that, if a fee-based system were introduced, a designated bag system would be the most effective to draw support from the residents. In addition, compared with the residents in Shanghai and Chengdu, residents from Shenyang—where economic incentive measures have not been introduced are found to be more actively engage in garbage sorting. They are also more receptive to a refuse charge system and policies requiring garbage sorting. This implies that mandatory garbage sorting would be more e ffective than economic measures.


**4. Tsai-Hill failure criteria assessment of longitudinal tensile strength**

Failure theory is essential in determining whether the composite has failed. Literature review has shown that results of failure prediction depend on failure criterion applied and one major failure criteria used in the industries is Tsai-Hill and

direction of applied load [55]. Although Jones [56] intuitively suggested that highest value of material properties may not necessarily occur along the principal material directions, rather it is essential that transverse reinforcement is needed in unidirec-

As can be seen in **Figure 5** that shear modulus peaked at 45° fiber orientation and shear modulus was symmetric at about 45° fiber orientation angle for both PEFBFC and PPSFC considered. This implies that the higher in-plane shear resistance is achievable when fiber orientation is 45°. Also the respective minimum value of 3622.99 and 3332.83 MPa at fiber orientation 0° for PEFBFC and PPSFC can be seen to gradually increase to maximum values of 3843.57 and 3731.758 MPa at fiber orientation 45° and then reversed parabolically at 90° where it again reaches to 3622.99 and 3332.84 MPa. Similar trend was obtained by Farooq and Myler [58] who developed efficient procedures for determination of mechanical properties of carbon fiber-reinforced laminated composite panels. This trend in which the value of *Gxy* peaks at 45° fiber orientation angle and lowers at 0° and 90° fiber orientation angle indicates that off-axis reinforcement is very necessary for robust shear stiff-

**Figure 6** shows variation of Poisson's ratio with fiber orientation, the graph depicts a gradual drop of major Poisson's ratio (*vxy*Þ for PEFBFC and PPSFC respectively from 0.38 and 0.29 when fibers are aligned at 0° orientation angle to a lowest value of 0.18 and 0.15 value when fibers were aligned at 90° orientation angle. Additionally, the minor Poissons ratio (*vyx*Þ for PEFBFC and PPSFC increased respectively from 0.18 and 0.15 when fibers are aligned at 0° orientation angle to a highest value of 0.38 and 0.29 value when fibers were aligned at 90° orientation angle. **Figure 7** depicts the variation of shear coupling coefficient with fiber orientation, equal magnitude of shear coupling effect was obtained at 45° fiber orientation angle for both PEFBFC and PPSFC considered. Gibson [57] reported that shear coupling coefficient is a measure of the amount of shear strain developed in the *xy* plane per unit normal strain along the direction of the applied normal stress *σx*. **Figure 7** clearly indicate that the maximum value of the shear coupling coefficient in the reference *x*-direction for PEFBFC and PPSFC was attained at 30° fiber orientation angle while the coefficient in the reference *y*-direction for PEFBFC and

tional fiber composites which are subjected to multi axial loading [57].

*Composite and Nanocomposite Materials - From Knowledge to Industrial Applications*

ness in unidirectional composites [57].

**Figure 5.**

**192**

*Variation of shear modulus with fiber orientation in PEFBFC and PPSFC.*

failure criteria. Additionally, since composites ultimate tensile strength and strain depend on the fiber orientation, a failure criterion must be used in which the applied stress system is also in material axis [54]. Tsai-Hill theory considers an interaction of the stresses in the fiber direction. It postulates that failure can only occur in reinforced composites when the failure index exceeds 1, hence Eq. (19) must be satisfied to avoid failure.

By considering an arbitrary positive angle θ with reference to the *x*-axis in **Figure 3**, Ihueze et al. [43] transformed the stresses within the global axes (*x*-*y*) into material axes 1–2 as given in Eq. (15)

$$\begin{Bmatrix} \sigma\_1\\ \sigma\_2\\ \tau\_{12} \end{Bmatrix} = \begin{bmatrix} c^2 & s^2 & 2sc\\ s^2 & c^2 & -2sc\\ -sc & s c & (c^2 - s^2) \end{bmatrix} \begin{Bmatrix} \sigma\_{\chi}\\ \sigma\_{\mathcal{V}}\\ \tau\_{\chi\chi} \end{Bmatrix} \tag{15}$$

where *c* = *cosθ* and *s* = *sinθ*. Taking longitudinal direction stresses as *σy* ¼ *τxy* ¼ 0 and thus

$$
\sigma\_1 = \sigma\_\text{x} \cos^2 \theta \tag{16}
$$

$$
\sigma\_2 = \sigma\_\text{x} \sin^2 \theta \tag{17}
$$

**5. Variation of tangential stress and modulus around a structural**

*Variation of longitudinal tensile strength with fiber orientation for PEFBFC and PPSFC.*

**S/N Orientation** *θ* **PEFBFC PPSFC** 0 410.15 288.1 5 195.86 152.635 10 108.786 86.8937 15 75.4556 60.6747 20 58.6356 47.3142 25 48.8262 39.5106 30 42.6439 34.6088 35 38.6038 31.4352 40 35.9607 29.4005 45 34.3043 28.1833 50 33.3926 27.5977 55 33.0716 27.5303 60 33.2311 27.9038 65 33.774 28.6492 70 34.5913 29.679 75 35.5418 30.8595 80 36.4447 31.9912 85 37.0995 32.8242 90 37.3397 33.133

*Strength Analysis and Variation of Elastic Properties in Plantain Fiber/Polyester Composites…*

*DOI: http://dx.doi.org/10.5772/intechopen.90890*

Structural discontinuity arising from holes in reinforced composites created for joining or access purposes causes stress concentration at the point of discontinuity [59].

**discontinuity**

**Figure 8.**

**195**

**Table 5.**

*Longitudinal tensile strength variation with fiber orientation angle.*

$$
\tau\_{12} = -\sigma\_{\text{x}} \cos \theta \sin \theta \tag{18}
$$

Considering Tsai-Hill failure criterion and setting the failure index as 1 for the composite failure to occur:

$$
\left(\frac{\sigma\_1}{S\_{u1}}\right)^2 + \left(\frac{\sigma\_2}{S\_{u2}}\right)^2 + \left(\frac{\tau\_{12}}{\tau\_{\max}}\right)^2 - \left(\frac{\sigma\_1}{S\_{u1}}\right)\left(\frac{\sigma\_2}{S\_{u1}}\right) = 1\tag{19}
$$

Substituting the appropriate value in Eq. (19) we have for PEFBFC

$$\left(\frac{\sigma\_{\text{x}}\cos^{2}\theta}{410.15}\right)^{2} + \left(\frac{\sigma\_{\text{x}}\sin^{2}\theta}{37.3397}\right)^{2} + \left(\frac{-\sigma\_{\text{x}}\cos\theta\sin\theta}{19.3100}\right)^{2} - \left(\frac{\sigma\_{\text{x}}\cos^{2}\theta}{410.15}\right)\left(\frac{\sigma\_{\text{x}}\sin^{2}\theta}{410.15}\right) = 1$$

$$\sigma\_{\text{x}, \text{PEFBFC}} = \sqrt{\frac{1}{\left(\cos^{4}\theta\_{\text{/410.15}^{2}} + \sin^{4}\theta\_{\text{/37.397}^{2}} + \cos^{2}\theta\sin^{2}\theta\_{\text{/3100}^{2}} - \cos^{2}\theta\sin^{2}\theta\_{\text{/410.15}^{2}}\right)}}$$

And for PPSFC

$$\left(\frac{\sigma\_x \cos^2 \theta}{288.10}\right)^2 + \left(\frac{\sigma\_x \sin^2 \theta}{33.1330}\right)^2 + \left(\frac{-\sigma\_x \cos \theta \sin \theta}{15.5700}\right)^2 - \left(\frac{\sigma\_x \cos^2 \theta}{288.10}\right)\left(\frac{\sigma\_x \sin^2 \theta}{288.10}\right) = 1$$

$$\sigma\_{\text{x, ppSFC}} = \sqrt{\frac{1}{\left(\cos^4 \theta \prime\_{288.10^2} + \sin^4 \theta \prime\_{31.330^2} + \cos^{20} \theta \sin^2 \theta \prime\_{15.5700^2} - \cos^{20} \theta \sin^2 \theta \prime\_{288.10^2}\right)}}$$

Hence the value for *σx* is then calculated for orientation ranging from 0° to 90° as shown in **Table 5**.

The variation of longitudinal tensile strength with fiber orientation for PEFBFC and PPSFC has been presented in **Figure 8**, it can be seen that the tensile strength equals 410.15 and 288.1 MPa which are the longitudinal tensile strength for PEFBFC and PPSFC respectively when fiber orientation angle is 0°; on the other hand, the tensile strength equals 37.3397 and 33.133 MPa which are the transverse tensile strength for PEFBFC and PPSFC respectively when fiber orientation angle is 90°.

*Strength Analysis and Variation of Elastic Properties in Plantain Fiber/Polyester Composites… DOI: http://dx.doi.org/10.5772/intechopen.90890*

#### **Table 5.**

failure criteria. Additionally, since composites ultimate tensile strength and strain depend on the fiber orientation, a failure criterion must be used in which the applied stress system is also in material axis [54]. Tsai-Hill theory considers an interaction of the stresses in the fiber direction. It postulates that failure can only occur in reinforced composites when the failure index exceeds 1, hence Eq. (19)

*Composite and Nanocomposite Materials - From Knowledge to Industrial Applications*

By considering an arbitrary positive angle θ with reference to the *x*-axis in **Figure 3**, Ihueze et al. [43] transformed the stresses within the global axes (*x*-*y*) into

2 2*sc*

2 ð Þ

� *σ*1 *Su*1 � � *σ*2

ffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi 1

� �

ffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi 1

� �

33*:*13302 þ *cos* 2*θ sin* 2*θ*

Hence the value for *σx* is then calculated for orientation ranging from 0° to 90°

37*:*33972 þ *cos* 2*θ sin* 2*θ*

3 7 5

8 ><

>:

*τ*12 ¼ �*σxcosθsinθ* (18)

*Su*1 � �

� � *σx sin* 2

19*:*31002 � *cos* 2*θ sin* 2*θ*

� � *σx sin* 2

15*:*57002 � *cos* 2*θ sin* 2*θ*

� *σx cos* 2*θ* 410*:*15

*=*

� *σx cos* 2*θ* 288*:*10

*=*

*σx σy τxy* 9 >=

>;

*θ* (16)

*θ* (17)

¼ 1 (19)

*θ* 410*:*15 � �

> *=*410*:*152

*θ* 288*:*10 � �

> *=*288*:*102

¼ 1

¼ 1

(15)

2 *c*2 �2*sc* �*sc sc c*2 � *s*

where *c* = *cosθ* and *s* = *sinθ*. Taking longitudinal direction stresses as *σy* ¼ *τxy* ¼ 0

*σ*1 ¼ *σx cos* 2

*σ*2 ¼ *σx sin* 2

Considering Tsai-Hill failure criterion and setting the failure index as 1 for the

þ *τ*12 *τmax* � �2

þ �*σxcosθsinθ* 19*:*3100 � �2

þ �*σxcosθsinθ* 15*:*5700 � �2

*=*

The variation of longitudinal tensile strength with fiber orientation for PEFBFC and PPSFC has been presented in **Figure 8**, it can be seen that the tensile strength equals 410.15 and 288.1 MPa which are the longitudinal tensile strength for PEFBFC and PPSFC respectively when fiber orientation angle is 0°; on the other hand, the tensile strength equals 37.3397 and 33.133 MPa which are the transverse tensile strength for PEFBFC and PPSFC respectively when fiber orientation

Substituting the appropriate value in Eq. (19) we have for PEFBFC

*=*

*c*2 *s*

*s*

2 6 4

must be satisfied to avoid failure.

and thus

composite failure to occur:

*σx cos* 2*θ* 410*:*15 � �2

*σx*, PEFBFC ¼

And for PPSFC

*σx cos* 2*θ* 288*:*10 � �2

*σx*, PPSFC ¼

as shown in **Table 5**.

angle is 90°.

**194**

*σ*1 *Su*1 � �2

þ *σx sin* 2

*cos*4θ*=*

þ *σx sin* 2

*cos* 4 *θ=*

s

s

þ *σ*2 *Su*2 � �2

*θ* 37*:*3397 � �2

*θ* 33*:*1330 � �2

410*:*152 þ *sin* 4*θ*

288*:*102 þ *sin* 4*θ*

material axes 1–2 as given in Eq. (15)

*σ*1 *σ*2 *τ*12 9 >= >; ¼

8 ><

>:

*Longitudinal tensile strength variation with fiber orientation angle.*

**Figure 8.** *Variation of longitudinal tensile strength with fiber orientation for PEFBFC and PPSFC.*