Fundamental study of two-phase flow in the porous media of polymer electrolyte membrane fuel cells (PEMFC)

Polymer electrolyte membrane fuel cells (PEMFC) is an electrochemical device that converts the chemical energy of fuels into electrical energy through electrochemical reactions. Due to the zero emissions and high efficiency, PEMFC has been regarded as one of the most promising future energy sources. However, water management in the PEM fuel cell is a critical issue for the effective cell operation and full-scale application. Sufficient water must be maintained in the membrane to facilitate proton transfer, but if it exists in excess, the water will flood the catalyst layer. The amount of water generation is directly and entirely contingent upon operating conditions. When liquid droplets form, the pore paths for transporting reactant through a porous diffusion media as well as a catalyst layer may be blocked resulting in the degradation of the cell\u27s performance. Therefore, it is important to understand the two-phase (i.e. mixture of liquid and gas) flow in the porous diffusion media to resolve issues due to the excess water in the cell. In this study, a physics-based one-dimensional isothermal mathematical model was developed to understand the effects of operating conditions (humidity conditions and current density) on the water distribution of the fuel cell. It was found that gas humidity conditions and operating current density has a significant impact on water distribution and should be considered during cell design. The transport of liquid water in equilibrium with water vapor and reactant gases in the porous diffusion media of the PEMFC was studied by implementing physics of two-phase flow in porous soil media into the model. The effects of surface properties (i.e. hydrophobicity and hydrophilicity), wetting characteristics, and pore structures (micro-pore and macro-pore) of porous diffusion media on liquid water transport were explored. It is evident that two-phase flow should be considered after reaching threshold operating conditions and hydrophobic diffusion media with larger contact angles enhances residual water removal from the cell. Composite pore structures (multi-diffusion layer) enhance water transport and reduce liquid saturation at catalyst layer. Since the liquid water formation depends on saturation pressure, which is a strong function of temperature, a thermal analysis model was studied to analyze temperature variation during operation. The effects of operating current densities and thermal conductivities of porous diffusion media on the temperature variation were investigated. The additional liquid water transport originated from temperature variation in the cell, known as phase change induced (PCI) flow, were introduced in the two-phase flow model

Awareness of rabies and response to dog bites in a Bangladesh community

Community awareness regarding rabies and treatment seeking behaviours are critical both for the prevention and control of the disease in human and animals. We conducted a study to explore people’s awareness about rabies, their attitudes towards dogs and practices associated with treating dog bites in Satkhira Sadar, a southwestern sub-district of Bangladesh. Of the total 3200 households (HHs) surveyed, the majority of the respondents have heard about rabies (73%) and there was a high level of awareness that dog bite is the main cause of rabies (86%), and that rabies can be prevented by vaccination (85%). However, 59% of the dog bite victims first seek treatment from traditional healers instead of visiting the hospitals, 29% received the rabies vaccine, 2% practiced proper wound washing with soap and water, while 4.8% have not taken any measures. None of the victims have received rabies immunoglobulin (RIG). Of the respondents, 5.2% reported a history of dog bite in at least one family member, and 11.8% reported a history of dog bite in domestic animals during the previous year. The HHs having a higher number of family members (OR: 1.13, 95% CI: 1.07–1.2), having a pet dog (OR: 2.1, 95% CI: 1.4–3.2) and caring or feeding a community dog (OR: 2.1, 95% CI: 1.4–2.9) showed an increased risk of getting a dog bite. Among the bite victims, 3.6% (n = 6) humans and 15.8% (n = 60) animals died. As a measure for dog population management (DPM), 56% preferred sterilization while the rest preferred killing of dogs. The current treatment seeking behaviours of the respondents should be improved through additional education and awareness programme and better availability for the provision of post-exposure prophylaxis in Bangladesh. We recommend scaling up national mass dog vaccination and DPM to reduce the burden of rabies cases and dog bites in Bangladesh

Complement to the Classroom (C2L): First language based e-materials platform for effective learning for multi-lingual young learners

This study will address the impactful and scalable solution to the challenges of multi-lingual communities facing access to education in Chittagong Hill Tracts (CHT), a southeastern region in Bangladesh. As a probable remedy for learning gap, this study will introduce a low-cost but accessible semi-online platform “Complement to Classroom (C2C)” to develop, upload, and utilize academic content in different mother languages to call for “no more language barrier” in education in CHT

REVISITING THE RELATIONSHIP BETWEEN CULTURE AND ENVIRONMENT OF THE A’CHIK INDIGENOUS COMMUNITY OF MEGHALAYA: A REVIEW

One of the issues and problem in the harmonious existence of all the life forms on the earth planet was believed to be the extinction of traditional culture of the indigenous tribe that has a significance linked with natural environment. The two components nature-culture work together and lead to unique features. In line, culture is the set of knowledge, practices, idealism that guides human to associate with the natural environment. Thus, culture can be defined as one of the assets into the paramount of harmonious existence of all the creatures. Coming to the A‟chik ethnic group of Meghalaya, like any other cultural groups of the North East, the A'chiks is very rich in their tradition and culture. Ethnically, for the A'chiks, the name itself is associated with natural environment. There was a historical narrative with regards to the origin and derivation of the name A‟chik. „A‟a‟ means „land‟ and „chik‟ means „hill‟. Thus, A‟chik means „hill‟ and „mande‟ means „man‟ or „hill man‟ (Mihir, 1995, p. 33). Thus, their association with nature was symbiotic and intimate. However, the impact of western culture and its associated aspects of modernity have greatly changed the tradition and culture of the A‟chik. The study is an attempt to give an insightful look into the A‟chik traditional cultural practices associated with natural environment. In view of the culture and tradition within the environment on the unprecedented ecological crisis in the name of development and modernity needs to look back and examine how culture and tradition is linked to environment. The study finding indicates that today one of the greatest challenges in the present global scenario was the crisis in environment on account of the globalization, the influence of modern culture, technological innovative, intermingling and cultural hegemony and hence the tribal cultures are on the way to extinction. The world is now engaged to search out means of tackle this grave catastrophe proves that our lives and practices have somehow gone astray. The natural resources are now subject to increasing destruction and reduction and even overgrazed out of existence. Hence, there was an urgent need to draw the attention of the mankind as well as culture and their environment in the era of modernization and globalization in the environmental degradation and climate changes

Evaluating Rice Biodiversity and Yields of Upland Rice Landraces Grown in Shifting Cultivation in Bandarban, Bangladesh

Shifting cultivation, popularly known as jhum, is a dominant form of agriculture in the Chattogram Hill Tracts (CHT) of Bangladesh with upland rice being the major component of the system. The region is known for its rice biodiversity, which is under threat. This study was an attempt to explore the extent of rice biodiversity and variation in rice yields observing 81 randomly selected shifting cultivation plots from 26 dispersedly located mountainous villages in four sub-districts of Bandarban, one of three districts of the CHT. A total of 28 landraces of upland rice was grown in shifting cultivation. Highest number of landraces (16) was found in sub-district Thanchi. Three landraces most frequently observed were Gunda, Maemonsing and Sadabinni. Rice grain yield varied between 1.421 t ha-1 and 3.442 t ha-1 across landraces with the highest being recorded for Patobi. Landrace Dilon the lowest yield. Relative performance of landraces Kobrokbinni, Maemonsing, Monthon, Patobi and PD were superior to standard BRRI dhan83 and Gunda in relation to grain yield. Some of these landraces having wider adaptability may be released as varieties

EFFECT OF PHOSPHORUS AND GIBBERELLIC ACID ON GROWTH AND YIELD OF TUBEROSE

A Thesis Submitted to the Department of Horticulture Sher-e-Bangla Agricultural University, Dhaka In partial fulfillment of the requirements for the degree of MASTER OF SCIENCE (MS) IN HORTIUCLTUREThe present study was carried out in the Horticulture Farm of Sher-e-Bangla Agricultural University, Dhaka, Bangladesh during August 2017 to October 2018 to study the effect of phosphorus and gibberellic acid on growth and yield of tuberose (Polianthes tuberosa). Four phosphorus levels viz P ii 0 = 0 kg P 2 O 5 ha -1 , P ha -1 , P 2 = 85 kg P 2 O 5 ha -1 and P 3 = 110 kg P 2 O 5 ha -1 and three GA 3 1 = 65 kg P levels viz. G = 0 ppm GA 3 , G 1 = 115 ppm GA 3 and G 2 =145 ppm GA were treated. The experiment was laid out in the two factors Randomized Complete Block Design (RCBD) with three replications. Regarding P application, P 3 3 (110 kg P 2 O 5 ha -1 ) gave the highest plant height (61.02 cm) and number of leaves plant -1 (7. 29.35) compared to control treatment but the highest yield parameters number of spike ha -1 (368.60 thousand), bulb yield (25.88 t ha -1 ) and bulblet yield (14.21 t ha -1 ) were found from the treatment P 2 (85 kg P 2 O 5 ha -1 ) whereas control treatment P 0 (0 kg P 2 O 5 ha -1 ) showed lowest results. In case of GA 3 application, G 2 (145 ppm GA ) showed highest growth and yield parameter and the highest number of spike ha -1 3 (362.30 thousand), bulb yield (25.38 t ha -1 ) and bulblet yield (14.00 t ha -1 ) were obtained from G ) whereas the lowest results were found from the control treatment G 2 ). Treatment combination of P and GA 3 , the highest number of spike ha (405.60 thousand), bulb yield (31.45 t ha -1 ), and bulblet yield (16.01 t ha -1 ) were found from P 2 G 2 combination whereas the lowest number of spike ha -1 (189.60 thousand), bulb yield (14.57 t ha -1 ) and bulblet yield (9.05 t ha -1 ) was found from the control treatment combination of P 0 G . In terms of economic analysis, the highest gross return (Tk. 471550), net return (Tk. 289337) and BCR (2.59) were also obtained from P 0 (85 kg P 2 O 5 ha -1 with 145 ppm GA ) whereas the lowest gross return (Tk. 227470), net return (Tk. 57703) and BCR (1.34) was obtained from P 3 0 G 0 0 (145 ppm GA 0 (0 ppm GA (no P and GA ). From the above results, it can be stated that that the P application @ 85 kg P 2 application @ 145 ppm can be considered for higher yield and economic return in commercial cultivation of tuberose

Peningkatan Perilaku Prosoial Melalui Penguatan Persepsi Atas Lingkungan Sekolah

Penelitian ini bertujuan untuk mengetahui pengaruh persepsi atas lingkungan sekolah terhadap perilaku prososial. Metode penelitian ini adalah survey dengan pendekatan kuantitatif. Sampel dalam penelitian ini berjumlah 71 siswa yang berada di SMK Negeri wilayah Jakarta Timur dengan ditetapkan menggunakan teknik purposive sampling dan proportional random sampling. Teknik pengumpulan data menggunakan angket atau kuesioner yang terdiri dari 30 pernyataan dengan menggunakan skala likert yang terdiri dari 5 pilihan jawaban dari sangat tidak setuju sampai sangat setuju. Data dianalisis dengan menggunakan uji regresi linear sederhana dengan uji t dan uji koefisien determinasi. Analisis regresi menunjukkan bahwa terdapat hubungan positif antara literasi digital dan keterampilan pendidik, dengan persamaan regresi Y = 5,204 + 0,651X. Koefisien korelasi menunjukkan hubungan yang kuat antara kedua variabel, sedangkan koefisien determinasi menunjukkan bahwa proporsi variasi perilaku prososial yang dapat ditingkatkan oleh persepsi siswa atas lingkungan sekolah adalah sebesar 47%. Dengan demikian, dapat disimpulkan bahwa persepsi atas lingkungan sekolah secara signifikan dapat mempengaruhi perilaku prososial

INFLUENCE OF MOTIVATION, SOCIAL SUPPORT AND BASIC NEED SATISFACTION ON BURNOUT AMONG FOOTBALL PLAYERS IN BANGLADESH

Football is ruminated in the guise of the most foremost and modish sports in Bangladesh reminiscent of other countries of the world, as sports are frolicked under prodigious coercion, young football athletes perpetually stumble into divergent circumstances which incorporate affirmative and apathetic scenarios confiding in athlete’s concurrent whereabouts & prospect dispatch which narrates to burnout. The perusal maneuvered motivation as an independent variable, basic need satisfaction which exerted as mediator variable and social support plied as moderator variable that governed young player’s burnout to ebb or to surge. The purpose of the study was to interrogate the relationship among burnout and motivation, social support, basic need satisfaction. The paper pursued quantitative technique to amass accessible data in which five hundred and twelve adolescent football players were surveyed in Bangladesh and their age ranged between 15 to 25 years. The survey questionnaire was in four tranches encompassing Athlete burnout questionnaire, Basic Need Satisfaction scale, Motivation questionnaire & SARASON Social Support scale; furthermore, the study wielded Pearson Correlation analysis, Moderated regression analysis and Process in the course of score reckoning. The study instituted that motivation and social support unconstructively associated with burnout and basic need satisfaction allied moderately with the burnout, when burnout escalates, motivation, social support, and basic need satisfaction went down or when burnout dwindles all of the independent variables augment. The research formed factors relationship with each other and comprehended coping tactic how athletes could trounce their melancholy, fatigue and mental grievance to burgeon their sports recital and would scrutinize players commotion towards their contented & constructive precinct as well

INFLUENCE OF MOTIVATION, SOCIAL SUPPORT AND BASIC NEED SATISFACTION ON BURNOUT AMONG FOOTBALL PLAYERS IN BANGLADESH

Football is ruminated in the guise of the most foremost and modish sports in Bangladesh reminiscent of other countries of the world, as sports are frolicked under prodigious coercion, young football athletes perpetually stumble into divergent circumstances which incorporate affirmative and apathetic scenarios confiding in athlete’s concurrent whereabouts & prospect dispatch which narrates to burnout. The perusal maneuvered motivation as an independent variable, basic need satisfaction which exerted as mediator variable and social support plied as moderator variable that governed young player’s burnout to ebb or to surge. The purpose of the study was to interrogate the relationship among burnout and motivation, social support, basic need satisfaction. The paper pursued quantitative technique to amass accessible data in which five hundred and twelve adolescent football players were surveyed in Bangladesh and their age ranged between 15 to 25 years. The survey questionnaire was in four tranches encompassing Athlete burnout questionnaire, Basic Need Satisfaction scale, Motivation questionnaire & SARASON Social Support scale; furthermore, the study wielded Pearson Correlation analysis, Moderated regression analysis and Process in the course of score reckoning. The study instituted that motivation and social support unconstructively associated with burnout and basic need satisfaction allied moderately with the burnout, when burnout escalates, motivation, social support, and basic need satisfaction went down or when burnout dwindles all of the independent variables augment. The research formed factors relationship with each other and comprehended coping tactic how athletes could trounce their melancholy, fatigue and mental grievance to burgeon their sports recital and would scrutinize players commotion towards their contented & constructive precinct as well.  Article visualizations