Search results

The paper reviews the application of the finite element method to the analysis of large‐deflection elasto‐plastic behaviour and traces the development of such a solution for plated structures. The accuracy of the approach is established by many comparisons with available solutions for isolated plates and conclusions are drawn on suitable idealizations for plated structures. The results of an analysis of a typical plate girder, allowing fully for the interaction between the component plates, are presented. Comparisons with experimentally measured values for the girder confirm the validity of the proposed approach for the study of the collapse modes of plated structures. The need for expensive experimentation is thereby reduced.

The purpose of this paper is to improve the surface electrical conductivity and corrosion resistance of AISI 430 stainless steel (430 SS) as bipolar plates for proton exchange membrane fuel cells (PEMFCs), a protective Nb-modified layer is formed onto stainless steel via the plasma surface diffusion alloying method. The effect of diffusion alloying time on electrochemical behavior and surface conductivity is evaluated.

In this work, the surface electrical conductivity and corrosion resistance of modified specimen are evaluated by the potentiodynamic and potentionstatic polarization tests. Moreover, the hydrophobicity is also investigated by contact angle measurement.

The Nb-modified 430 SS treated by 1.5 h (1.5Nb) presented a lower passivation current density, lower interfacial contact resistance and a higher hydrophobicity than other modified specimens. Moreover, the 1.5 Nb specimen presents a smoother surface than other modified specimens after potentionstatic polarization tests.

The effect of diffusion alloying time on electrochemical behavior, surface conductivity and hydrophobicity of modified specimen is evaluated. The probable anti-corrosion mechanism of Nb-modified specimen in simulated acid PEMFC cathode environment is presented.

The mucilage of the Linum usitatissimum L. seed (Linseed) is one of the natural mucilages that presents a great potential to provide a food hydrocolloid with potential applications in both food and pharmaceutical industries. To increase the yield and quality of linseed oil during its production process, it is necessary to previously extract its polysaccharides. Because of this, flax mucilage production can be made viable as a byproduct of oil extraction process, which is already a product of high commercial value consolidated in the market. Thus, the purpose of this work is to optimize the mucilage extraction process of L. usitatissimum L. using the normal-boundary intersection (NBI) multiobjective optimization method.

Currently, the variables of the process of polysaccharide extraction from different sources are optimized using the response surface methodology. However, when the optimal points of the responses are conflicting it is necessary to study the best conditions to achieve a balance between these conflicting objectives (trade-offs) and to explore the available options it is necessary to formulate an optimization problem with multiple objectives. The multiobjective optimization method used in this work was the NBI developed to find uniformly distributed and continuous Pareto optimal solutions for a nonlinear multiobjective problem.

The optimum extraction point to obtain the maximum fiber concentration in the extracted material was pH 3.81, temperature of 46°C, time of 13.46 h. The maximum extraction yield of flaxseed was pH 6.45, temperature of 65°C, time of 14.41 h. This result confirms the trade-off relationship between the objectives. NBI approach was able to find uniformly distributed Pareto optimal solutions, which allows to analyze the behavior of the trade-off relationship. Thus, the decision-maker can set extraction conditions to achieve desired characteristics in mucilage.

The novelty of this paper is to confirm the existence of a trade-off relationship between the productivity parameter (yield) and the quality parameter (fiber concentration in the extracted material) during the flaxseed mucilage extraction process. The NBI approach was able to find uniformly distributed Pareto optimal solutions, which allows us to analyze the behavior of the trade-off relationship. This allows the decision-making to the extraction conditions according to the desired characteristics of the final product, thus being able to direct the extraction for the best applicability of the mucilage.

The inclusion of natural antioxidants and nanoparticles into edible coatings can improve their structure, functionality and applicability in foods. This study aims to determine the antibacterial effect of new nano-composite based on bean pod shell gum (BPSG), silver nanoparticle (SNP) and herbal essential oil (EO).

For this purpose, BPSG (4 per cent w/v), SNP (0.5-1 per cent w/v) and Helichrysum arenarium EO (1-2 per cent v/v) were mixed. After preparation the edible film, the antibacterial activity was tested on five food-borne pathogenic bacteria in two categories including two-gram positives and three-gram negatives bacteria. The EO composition was determined by GC–mass spectrometry and the antibacterial activity was tested using disk diffusion test.

Results showed that gram-positive bacteria were more susceptible than gram-negative bacteria. Increasing Helichrysum arenarium EO and SNP content increased antimicrobial activity of the edible film based on BPSG, so that the treatment containing 2 per cent v/v Helichrysum arenarium EO and 1 per cent w/v SNP led to the highest inhibition zone (8.1-13.1 mm) compared to treatment containing 1 per cent v/v Helichrysum arenarium EO and 0.5 per cent w/v SNP with inhibition zone range of 5.4-9.9 mm and the difference was statistically significant (p = 0.41). Also, the chemical composition analysis of the EO identified a total of 38 compounds in which a-pinene (32 per cent), 1,8-cineole (16 per cent), α-humulene (15 per cent) and ß-caryophyllene (8 per cent) were the main fractions. Other separated components accounted less than 29 per cent of the oil.

In general, SNP and Helichrysum arenarium EO improved the functional properties including the antimicrobial activity of the edible film based on BPSG, which increases the potential to be used as active packaging for fresh products.

This chapter aims to identify, analyse, classify and rank the sustainability indices and internationalisation challenges of the footwear industry in the emerging economy of Iran. This would provide deeper decision-making insights into Iranian footwear businesses. First, a list of sustainability indices and internationalisation challenges was obtained by reviewing the literature. Then, a combination of multi-criteria decision-making (MCDM) approaches was implemented. The initial sustainability indices and internationalisation challenges were screened using the fuzzy Delphi method, keeping a total of 14 criteria. The best–worst method (BWM) was employed to weigh and rank the criteria. The interpretive structural modelling (ISM) technique and cross-impact matrix applied in MICMAC were employed to visualise the conceptual model based on the levels and classification of the important criteria for the internationalisation of the Iranian footwear industry. The 14 criteria were demonstrated to be important in internationalisation. The most critical sustainability indices were reducing hazardous substances in leather tanning and labour education and training. In contrast, exchange rate instability in Iran’s economy and strict chemical regulations for clothing and footwear were found to be the most important internationalisation challenges. Hence, these criteria should be considered in the internationalisation strategies of the Iranian footwear industry. A combined multilayer sustainable decision-making approach was used to analyse the Iranian footwear industry’s essential sustainability indices and internationalisation challenges. Furthermore, implications and insights are offered to footwear businesses for future decision-making.

The purpose of this paper is to develop a real-time trajectory planner with optimal maneuver for autonomous vehicles to deal with dynamic obstacles during parallel parking.

To deal with dynamic obstacles for autonomous vehicles during parking, a long- and short-term mixed trajectory planning algorithm is proposed in this paper. In long term, considering obstacle behavior, A-star algorithm was improved by RS curve and potential function via spatio-temporal map to obtain a safe and efficient initial trajectory. In short term, this paper proposes a nonlinear model predictive control trajectory optimizer to smooth and adjust the trajectory online based on the vehicle kinematic model. Moreover, the proposed method is simulated and verified in four common dynamic parking scenarios by ACADO Toolkit and QPOASE solver.

Compared with the spline optimization method, the results show that the proposed method can generate efficient obstacle avoidance strategies, safe parking trajectories and control parameters such as the front wheel angle and velocity in high-efficient central processing units.

It is aimed at improving the robustness of automatic parking system and providing a reference for decision-making in a dynamic environment.

To measure the dynamic features of compassion as an emotional and behavioral construct, the present research used a univariate latent growth modeling (LGM) approach within the structural equation modeling (SEM) framework. The aim was to trace the dynamic development of compassion longitudinally in accounting and business students during a three-credit English course at university.

The suggested method ensures the measurement invariance over time, deals with the first order latent variable, traces its growth and takes into account the measurement errors. This longitudinal analytical method was used to explore the initial state and the growth of compassion in four points of time during a language course. The data were collected from 60 adult accounting and business students in four time phases using Sprecher and Fehr's Compassionate Love Scale and were analyzed in Mplus 8.4 with univariate LGM.

The model fit was accepted and the invariance of the latent factor was confirmed over time. The negative covariance between intercept and slope (second-order latent variables) suggested that lower initial scores in L2 learners' compassion show a faster increase in compassion over time as the mean of slope is larger than that of the intercept. L2 learners who started off at a higher level of compassion showed a slower change in compassion over time. This can be at least partly explained by the teacher's motivating role or learners' compassion but needs to be further explored in complementary qualitative phases for deeper insights.

In the present research, awareness was raised of the developmental nature of compassion as an emotional and behavioral construct essential to the accounting and business profession. The great strength of this research lies in the dynamic approach to the compassion construct and the LGM used to capture the temporal growth of compassion and how it evolved through the L2 course.

The purpose of this paper is to evaluate mentoring behaviours in a public medical school in Malaysia and examine factors associated with those mentoring behaviours. The study is important because effective mentoring promotes the personal and professional growth of mentees.

A cross-sectional study was conducted with a population of 632 medical students. The authors used the Mentor Behaviour Scale (MBS) to measure four domains of mentoring behaviour: mentoring relationship structure, engagement, autonomy support and competency support. The authors evaluated the scoring of these domains as high, moderate or low scores.

A total of 508 (80.4 per cent) medical students in Years 2–5 participated in this study. Mentoring relationship structure, engagement and competency support were perceived as moderate scores, whereas autonomy support was perceived as a low score. Students in the early phases of study had better attitudes regarding mentoring behaviours. More frequent meetings and longer duration of meetings were significantly associated with better attitudes towards mentoring behaviour.

This paper evaluates contemporary mentoring behaviours in a Malaysian public medical school and contributes to non-western literature on mentoring. These behaviours were reflected in the four domains of the theory-based MBS.

This collaborative project, undertaken in the context of higher education in England, examined students’ motivations for undertaking a voluntary extra‐curricular mentoring role with young people in public care. It also considered students’ perspectives on what they gained from this experience.

The research was undertaken using a qualitative case study approach, with a focus on students undertaking mentoring in addition to their studies. The case study was a community project that drew on student volunteers to mentor children and young people who are looked after by the local authority. Methods included semi‐structured interviews, focus groups, development of individual exemplars, and the use of Web2 technologies, specifically a blog site and vodcasts. Data were collected between September 2010 and May 2011.

Findings reported in this paper demonstrate the reasons students engaged with mentoring looked after children as an extra‐curricular activity and the benefits they gained from this experience. As such, institutions and educators might consider how student engagement in mentoring can be valued and embedded in the wider student experience.

This literature provides evidence of mentoring as an important social and political phenomenon. Whilst much is known about benefits to mentees and, to a lesser degree, for mentors in the mentoring relationship, this research explores the issues in more depth by considering the interface between being a mentor and completing undergraduate or postgraduate level studies. In particular it discusses the potential for mentoring to become embedded within the curriculum to ensure education for sustainable futures.