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The purpose of this paper is to present the results of analysis of the transport gases and liquid water between the gas diffusion layer (GDL) and gas flow channel (GFC) of proton exchange membrane fuel cells (PEMFCs). These results are then used to describe the effects of the GDL‐GFC interfacial conditions on the general performance of PEMFCs.

This analysis utilizes finite element analysis commercial codes to illustrate the transport of fluids. The gas transport data obtained from the solution are compared with the established works of others. The liquid transport processes are modeled using the Darcy equation coupled with a saturation‐capillary pressure function (the Leverett function) and assuming no phase change. In addition, the boundary conditions for the liquid transport equation are varied in order to show the extent of non‐uniformities at the GDL‐GFC interface.

Analysis shows that water dispersion from the GDL‐GFC interface extends across the GDL to its other side, and eventually reduces the performance of the PEMFC.

It is well known that CFD simulation of fuel cells is, in general, still facing significant challenges due to the limited understanding of the complex physical and chemical processes existing within the fuel cell. The model is now under further development to improve its capabilities and undergoing further validations.

The simulations can provide detailed information on some of the key fluid dynamics, physical and chemical/electro‐chemical processes that exist in liquid dispersion at the interface of GDL‐GFC in fuel cells which are critical for fuel cell design and optimization.

The simulation can be used to understand liquid dispersion at the interface of GDL‐GFC and provide and alternative to experimental investigations in order to improve the performance of fuel cell.

The purpose of this paper is to investigate the thermal performance of the cooling plates with conventional straight channel and wavy channel designs.

A three-dimensional model involving coupled fluid flow and heat transfer processes is developed to study the thermal performance of the cooling plates. The effects of wavelength and amplitude on the cooling performance are also studied. In addition, two novel wavy channels with varying wavelength are proposed and investigated.

The simulated results are compared in terms of pressure drop, average temperature, maximum surface temperature, temperature difference between the maximum temperature and minimum temperature and surface temperature uniformity index. It is concluded that the cooling performance is significantly improved by the wavy channel.

The current study can improve the understanding of transport characterization of the cooling plates with wavy channel design and provide guidelines for the design of cooling plates.

The design of cooling plates with wavy channels can be used in proton exchange membrane fuel cells to improve the cooling performance.

The purpose of this paper is to investigate the effects of hydrogen humidity on the performance of air-breathing proton exchange membrane (PEM) fuel cells.

An efficient mathematical model for air-breathing PEM fuel cells has been built in MATLAB. The sensitivity of the fuel cell performance to the heat transfer coefficient is investigated first. The effect of hydrogen humidity is also studied. In addition, under different hydrogen humidities, the most appropriate thickness of the gas diffusion layer (GDL) is investigated.

The heat transfer coefficient dictates the performance limiting mode of the air-breathing PEM fuel cell, the modelled air-breathing fuel cell is limited by the dry-out of the membrane at high current densities. The performance of the fuel cell is mainly influenced by the hydrogen humidity. Besides, an optimal cathode GDL and relatively thinner anode GDL are favoured to achieve a good performance of the fuel cell.

The current study improves the understanding of the effect of the hydrogen humidity in air-breathing fuel cells and this new model can be used to investigate different component properties in real designs.

The hydrogen relative humidity and the GDL thickness can be controlled to improve the performance of air-breathing fuel cells.

Functionalization of organic cotton fabrics (OCFs) by in situ deposition of chitosan reduced-stabilized silver nanoparticles (AgNPs). No other toxic chemicals used to warrant an ecofriendly synthesis protocol. Human toxicity of silver systematically avoided to use as textile clothing. Primary colors (nearly-red, yellow and blue) were imparted on OCFs via localized surface plasmon resonance (LSPR) of AgNPs. Decent mechanical properties and laundering durability in terms of antibacterial/fastness test improved mechanical properties.

Silver nanoparticles can be synthesized by using silver nitrate along with commercially available chitosan. Due to the surface LSPR property of silver nanoparticles, it exhibits versatile colors depending on the synthesizing procedures. The coloration occurs due to the electrostatic interaction between the AgNPs and chitosan-treated OCF. The nanotreated fabrics provide excellent mechanical properties with improved antibacterial effects.

X-ray fluorescence (XRF) analysis quantifies the developed materials in the substrates. Scanning electron microscopy (SEM) characterization indicates the appearance and morphologies of silver nanoparticles into the fabric surface after the coloration process. It proves that the treated cotton knit fabric exhibits the LSPR optical features of AgNPs. The antibacterial and mechanical properties confirm the improved functionality of products.

Improved mechanical properties, antibacterial performances and coloration effects on organic cotton substrates in terms of chitosan-mediated nanosilver are not yet studied.

Commercial areas and bedestens (covered bazaars) are important public areas in Turkish cities and towns. These areas and buildings are essential in that they contribute vital economic and social characteristics to Turkish cities and towns. In the Ottoman period, these commercial areas, alongside inns, baths, mosques, and stores, were engaged in trading and manufacturing and formed a central part of life for the residents. The number of bedestens in a given city was dependent on the size of the city or town. All social, administrative, and economic activities were organized within these bedestens. Commercial structures, in which the bedestens are located, with different functions, such as arasta, inns, markets, covered markets, and stores, are the main components of the commercial districts. These structures were built by the order of the Sultan for the purpose of reviving and providing direction to the economic life of the city or town. One of the key components of these commercial structures was the bedestens. In terms of Turkish culture, a bedesten can be defined as the heart of the commercial district. Although these structures were built to sell textiles, they later functioned as places where antiques and/or valuable goods were also sold. Bedestens were usually a unique type of structure, with masonry masses between wooden stores located in the middle of the trade center of the city or town. The top of the bedesten, which was usually built as one storey and rectangular in shape, had a domed roof covered with lead. In this study, spatial analyses of these important architectural elements were conducted in terms of city planning, folk culture and commercial life. The bedestens selected for the study were those in historical cities located at major commercial road axes from the Ottoman period. The bedestens in these historical cities were examined, within the context of their planning, and assessments were made. The relations that these structures have with each other in general, and their common and different features, were also investigated.

The purpose of this paper is to demonstrate the development of an aircraft-type autonomous portable drone suitable for surveillance and disaster management. The drone is capable of flying at a maximum speed of 76 km/h. This portable drone comprises five distinct parts those are easily installable within several minutes and can be fit in a small portable kit. The drone consists of a ballistic recovery system, allowing the drone landing vertically. The integrated high-definition camera sends real-time video stream of desired area to the ground control station. In addition, the drone is capable of carrying ~1.8 kg of payload.

In order to design and develop the portable drone, the authors sub-divided the research activities in six fundamental steps: survey of the current drone technologies, design the system architecture of the drone, simulation and modeling of various modules of the drone, development of various modules of the drone and their performance analysis, integration of various modules of the drone, and real-life performance analysis and finalization.

Experimental results: the cruise speed of the drone was in the range between 45 and 62 km/h. The drone was capable of landing vertically using the ballistic recovery system attached with it. On the contrary, the drone can transmit real-time video to the ground control station and, thus, suitable for surveillance. The audio system of the drone can be used for announcement of emergency messages. The drone can carry 1.8 kg of payload and can be used during disaster management. The drone parts are installed within 10 min and fit in a small carrying box.

The autonomous aircraft-type portable drone has a wide range of applications including surveillance, traffic jam monitoring and disaster management.

The cost of the cost-effective drone is within $700 and creates opportunities for the deployment in the least developed countries.

The autonomous aircraft-type portable drone along with the ballistic recovery system were designed and developed by the authors using their won technology.

This study has conducted exploratory research to understand who should comprise the members of a resilient supply chain for promoting an entrepreneurial ecosystem of a startup project and to determine the mechanisms for the balanced coexistence of all stakeholders. This is necessary to ensure mutual benefits for all stakeholders, each of whom has multidimensional interests. Additionally, this supply chain must be able to withstand any potential disruption risks.

This research has employed a mixed-design approach. In this context, the study conducted an extensive qualitative and quantitative investigation, including 30 interviews and a survey involving 180 potential stakeholders in this supply network, respectively in the capital city of Bangladesh, Dhaka. The analysis of the interviews utilized principles of matrix thinking, while structural equation modeling (SEM) through LISREL was employed to understand cause-and-effect relationships.

Network, platform and governance—these three independent constructs have the potential to contribute to the dependent construct, a resilient supply chain, aimed at promoting an entrepreneurial ecosystem for startup projects. It has been revealed that the management of such projects depends on the rules and regulations within the ecosystem. An excellent governance mechanism is essential for this purpose. To facilitate coexistence, the establishment of a platform is crucial, where cooperation among all members is mandatory.

For practitioners, three distinctive but closely interdependent issues are explored and resolved in this philanthropic study. It has unfolded the elements of any startup project with essential settings.

The identification of the structural dynamics of potential stakeholders within the entrepreneurial ecosystem of startups is largely absent in existing literature. Therefore, there is a need to comprehensively investigate the entire network, including their roles, responsibilities and associations. This study makes a significant and novel contribution to the existing literature. Academics and practitioners alike have ample opportunities to learn from this new aspect of relationships across three distinct areas: the entrepreneurial ecosystem, startup projects and the development of a resilient supply chain.

Diabetes mellitus is becoming a growing concern worldwide. Hence, the purpose of this study is to assess the magnitude of poor glycemic control and to identify the determinants of poor glycemic control among diabetic patients attending a tertiary care hospital in Bangladesh.

This cross-sectional study was conducted among 732 diabetes patients seeking care at the outpatient department of Bangladesh Institute of Health Sciences Hospital, Dhaka, Bangladesh. Information, including glycemic status, was collected from patients’ medical records using a structured questionnaire.

About 87.6% of the patients were found to have poor glycemic control (glycosylated hemoglobin = 7%). Variables that were significant in bivariate analysis were put into a multivariate model where the factors associated with poor glycemic control were patients aged 41–60 years (odds ratio (OR)=2.26; 95% confidence interval (CI): 1.19–4.32, p = 0.013), suffering from diabetes for > 7 years (OR = 1.84; 95% CI: 1.12–2.99, p = 0.015), using insulin (OR = 2.34; 95% CI: 1.23–4.47; p = 0.010) or diet alone (OR = 0.20; 95% CI: 0.05–0.80, p = 0.023) as a type of diabetes treatment and proper use of medicine (OR = 0.37; 95% CI: 0.17–0.82, p = 0.015).

The high prevalence of poor glycemic control among diabetic patients is evident; therefore, strategic management and proper attention focusing on the predictors of poor glycemic control are necessary to reduce the long-term complications of diabetes.

This study aims to propose a model to elevate the financial empowerment of Muslim women by rejuvenating the practice of Mahr in society and facilitating the affordability of men to pay that Mahr amount.

The approach of this study is to offer a model through the interest-free savings-based finance concept. The model comprises four stages; each stage of the model is mathematically formulated and graphically explained to ensure clarity and coherence. To further investigate the issue, the authors use a convenient sampling method to ask a small sample size of respondents (women) from different countries about their financial contribution and empowerment in the family.

This model enables women to turn their exclusive financial right into a source of earning without borrowing from any source or paying interest on the principal amount. Besides, it encourages accelerating men’s obligation to pay the Mahr to the women immediately during the marriage ceremony by facilitating men’s affordability. Almost 45% of respondents state that a woman’s financial contribution exalts her decision-making power and strengthens her financial position in the family.

The authors attempt to revitalize Mahr practice in Muslim society to accelerate the process of receiving a woman’s exclusive financial right and empower a family as a whole through the Mahr model.

Considering the model’s uniqueness, the developed and proposed Mahr model in this research is novel; to the best of the authors’ knowledge, no other study has been conducted and developed such a model using the Mahr concept.

On its way to develop a smart grid in Indonesia, one key enabler in the early stage of implementation is advanced metering infrastructure (AMI). Thus, Perusahaan Listrik Negara (PLN), an electrical energy utility company owned by the government of the Republic of Indonesia as the only electricity utility company servicing customers from upstream to downstream in Indonesia, has started AMI program at some main cities. With AMI, real-time energy consumption profile, energy meter status and condition, and customer power quality can be acquired. Subsequently, these data collected by AMI can be used for further smart grid implementation by such IT systems and big data analysis. Instead of its function for smart grid backbone, AMI also significantly support smart energy on the city as a part of smart city initiatives. Nevertheless, its implementation requires more investment than the conventional metering system. This investment needs to be evaluated to define whether AMI is feasible and viable or not. This chapter is intended to observe the feasibility of AMI implementation in Indonesia using cost-benefit analysis (CBA). Two schemes were used as study objects, one scheme in which the communication infrastructure was managed by PLN itself, and the other one in which the communication infrastructure was managed by a third party. From the analysis, it appears that both schemes are proven to be feasible.