Removal of Remazol Red RR from Aqueous Solution by Glass Supported Films of Synthesized ZnO Nanoparticles

The nanoparticles of ZnO (n-ZnO) have been synthesized by a sol-gel method and characterized by UV-visible and FTIR spectroscopy, scanning electron microscopy (SEM), energy dispersive X-Ray spectrometry (EDX) and powder X-ray diffractometry (XRD). Precursor of n-ZnO particles were prepared via a non-aqueous route, which was calcined at 500oC. These particles were then deposited on a glass substrate for adsorption and photodegradation of a typical textile dye, Remazol Red R (RRR). Especially, the high surface to volume ratio of nanoparticles has appealed much attention to use these particles both as an adsorbent and a photocatalyst. A comparative study was carried out between n-ZnO and a commercially available ZnO (c-ZnO) to investigate the removal efficiency of RRR from its aqueous solution under different conditions. The removal efficiency has been optimized by varying several operating variables and the highest performance has been obtained with 0.115 g/slide of ZnO and 0.5 × 10-4 M aqueous solution of RRR under sunlight irradiation. It is important to note that the use of the films of ZnO in the presence of solar light makes it suitable for recycling and causes no secondary environmental pollution.

Relationship of Depression, Aging and Immune System During Covid-19 Pandemic: A Review

COVID-19 is a highly contagious virus that first appeared in China in December 2019. It has affected over 157 million people and killed over 3.2 million. The paper reviews the function of the immune system for COVID-19 prevention, depression, and anxiety due to COVID-19 and their effects on the immune system and the relationship of aging with the immune system and depression and anxiety. It has been found that several elderly people lack the coping mechanisms required to deal with the stress caused by COVID-19. Hence, identifying the factors and mechanisms that lead to this resilience will aid in the development of preventive measures for certain elderly people and groups with more severe mental health problems. Additionally, it would be beneficial to understand how technology could be leveraged to accomplish this goal. During the pandemic, various steps such as social isolation, quarantine, and self-isolation are needed to be implemented properly to slow the spread of the virus. Meanwhile, to help halt the pandemic, everybody must be vaccinated as soon as possible until any bans on social gatherings and social isolation can be removed, allowing other sectors such as schooling, social activities, and life to resume normalcy.

IMPACT OF COVID-19 PANDEMIC ON MENTAL HEALTH AMONG BANGLADESHI SENIOR CITIZENS: A CROSS-SECTIONAL STUDY

Novel Coronavirus (COVID-19) is a dangerous virus that was first emerged in China at December 2019. It has already infected more than 128 million people and killed more than 2.8 million people. The main purpose of this paper is to find out the present mental condition of Bangladeshi Senior Citizens in Dhaka city to overcome their loneliness or boringness. A systematic cross-sectional online survey regarding COVID-19 has been conducted from June 15 to June 25, 2020. After developing questionnaires utilizing Google form, it has been sent out to the participants using an online platform and the responses of the participants have been recorded. A total of 280 participants (100 female and 180 male) completed the survey. The average age of them is about 60 years. It has been observed that maximum male participants (58.3%) felt financial stress and maximum female participants (56%) felt horrified due to COVID-19. Additionally, it has been found that maximum male and female participants were utilized more time in social media then the normal time. Since COVID-19 has already become a major issue all over the world, it is necessary to identify the mental health conditions and activities of people during this pandemic situation so that appropriate measures can be taken. More research should be conducted regarding mental health impact and possible solutions. Hopefully, it will ease to provide fruitful information especially for the community health workers with a view to helping them tackle these psychological fitness-related issues in response to other similar societal disasters. After the pandemic, follow-up should be made in order to improve mental health.

FACTORS AFFECTING BRAND LOYALTY IN THE FOOTWEAR INDUSTRY – “A CASE STUDY OF BANGLADESH

The Footwear Industry is an important section of the leather industry in Bangladesh. Bangladesh has been ranked 8th in terms of footwear production in the world in 2016. The purpose of this research is to investigate how the respondents are influenced by factors of brand loyalty towards the footwear industry. In order to increase customer satisfaction and drive them to be brand loyalists, marketers are encouraged to develop aggressive marketing programs. The five factors of Brand loyalty are Product Quality, Service Quality, Price, Promotion and Customer Satisfaction. Questionnaires were distributed and self-administered to 30 respondents. Descriptive analysis, Correlation, Model Summary, ANOVA and Coefficient were used in this study. The research results showed that there is a positive and significant relationship between factors of Relationship Quality and Brand loyalty (Product Quality, Service Quality, Price, Promotion and Customer Satisfaction) with the footwear industry.

A STUDY ON PIGEON FARMING SYSTEM IN HAKIMPUR UPAZILA OF DINAJPUR DISTRICT IN BANGLADESH

A survey was carried out to investigate the pigeon farming system in Hakimpur Upazila at Dinajpur District (Bangladesh). The study was conducted during the period of October 2019 to December 2019. Data were collected from 10 farmers randomly. A questionnaire was developed to collect data from the selected farms located in Hakimpur Upazila. Collected data were different breeds, housing, feeding, management, marketing of pigeon, diseases and problems of farming. There were 8 different breeds in the ten farms. The average cost of housing per bird was 46 Taka and the average height of the house was 3.6 m. The average feed intake was 37gm per bird per day. Per year production from a pair of pigeons was 9-10 pairs. The average body weight of per squab was found about 350gm to 400gm at 30 days of marketing age. The selling price varies from 150 Taka to 200 Taka per squab. Common diseases were Pox, ND, Salmonellosis and mineral deficiency affected the birds. The average mortality rate was 6%. Around 25% of farms were vaccinated by BCRDV and Pox vaccines. Most of the pigeon farmers rear pigeon in small-scale scavenging systems with supplementary feeding. Pigeon farming may be increased with government initiatives providing training to farmers and extending loans. Further study is needed among different breeds and varieties of pigeons available in Bangladesh for better performance.

Electrical Simulation and Optimization of PTB7:PC70BM Based Organic Solar Cell Using GPVDM Simulation Software

The growing requirement for electricity and its inadequate fossil fuel supply is a global concern that's why organic solar cell (OSC) devices had more attraction in the last decades for their practical application. In this research study, GPVDM software is considered, a 3-D photovoltaic device model, used to observe the outcomes of PTB7: PC70BM based organic solar cell. The organic solar cell comprises a PTB7:PC70BM as an active layer, indium tin oxide (ITO) serving as a transparent conducting oxide, and front electrode, PEDOT: PSS for efficient transporting of holes, while Al is taken as a back metal electrode. The electrical simulation via GPVDM has been performed at different active layer thicknesses and charge carrier mobility. Furthermore, the influence of varying different HTM layers had also been studied. The optimum efficiency of OSC is obtained at 200 nm active layer thickness and carrier mobility of 2.46 x 106 m2/Vs. The outcomes and performance of the simulated organic solar cell are compared with the practically implemented organic solar cell. This research also suggests a possible path toward the efficient implementation of organic solar cells by modifying factors that are significantly reliant on the performance and outcomes of OSCs.

Accelerating Learners’ Self-confidence Level in Second Language Acquisition: A Qualitative Study

Second Language Acquisition (SLA) is a complex psychosomatic process. As per educational psychology, its acquisition process depends on some affective determinants related to learners' self-confidence that accelerates learners’ zeal of learning the language. However, studies are rare to empirically explore the factors or the ways that help learners build their self-confidence level. Thus, the prime focus of this study is to find out factors associated with accelerating learners’ self-confidence in SLA through a qualitative case study. Data have been collected through semi-structured interviews carried out over the phone due to the COVID-19 pandemic. A total of 13 respondents (7 boys and 6 girls) have been interviewed who have recently completed their postgraduation. The obtained data have been analyzed with the help of the content analysis technique. The study finds that the self-confidence of a learner gets accelerated by three main factors like motivational factor, social factor, and environmental factor which motivate a learner to learn L2. Based on the findings, some policy recommendations have been suggested to further improve L2 learners’ self-confidence level.

AN ASSESSMENT OF POULTRY REARING AND HYGIENIC MANAGEMENT OF BROILER FARMS OF COX’S BAZAR DISTRICT IN BANGLADESH

Poultry industry is one of the most booming industry in the Cox’s bazar district. This study was carried out to assess the hygienic practices and also to improve the broiler meat safety. Currently, every country in the world is increasing their effort to improve food safety to reduce the food safety risk. The data for this study was collected from the desk research, observation, survey, and interviews of poultry farmers. Twenty broiler farmers were surveyed by using questionnaire. The study revealed that the majority of the farmers are doing broiler farming as their main source of income. The flock size is around 501-1000 of the larger number of farms and on an average farmers are rearing 5.57 cycles per year. The study recommended some implication to improve hygienic practices of broiler and to reduce the foodborne illness of the district as well.