Study Of Pd-Ag Membranes With An Intermediate Oxide Layer Fabricated By Surfactant Induced Electroless Plating (Siep)

Uses of fossil fuels in transportation and power generation release greenhouse gases. Hydrogen has the potential to be an alternative clean energy carrier. Hydrogen fueled proton exchange membrane fuel cell (PEMFC) can be used in transportation and stationary power generation to reduce greenhouse gas emissions. However, high purity hydrogen is required for PEMFC. In the current work, dense Pd-Ag composite membranes with an oxide layer on microporous stainless steel substrate (MPSS) were fabricated by surfactant induced electroless plating (SIEP) process for hydrogen separation. Prior to palladium/silver metal deposition, the MPSS disc was oxidized in stagnant air at 500 ºC for 18 h. A cationic surfactant, dodecyl trimethyl ammonium bromide (DTAB) was used in Pd- and Ag-bath for the sequential deposition of metals on MPSS substrates to remove the gas bubbles (N2 and NH3) produced during electroless plating. In this work, 4 CMC and 0.3 CMC (1 CMC = 15.6 mM) of DTAB were used in Pd- and Ag-bath respectively. Addition of a high amount of DTAB leads non-uniform Ag deposition and takes longer time to fabricate defect free Pd-Ag membrane. However, the average particle sizes were found to be 1.4 μm to 2.5 μm, which were relatively larger than the Pd-Ag film particle size using 4 CMC of DTAB in both Pd- and Ag-bath. Morphological features of the fabricated Pd-Ag membranes at pre- and post-annealing conditions were studied by using SEM, XRD, and EDS. The Pd-Ag membrane with an oxide layer showed higher permeability and selectivity in comparison to the membrane without oxide layer. However, at elevated temperature (550 ºC) the membrane showed a sharp decline in selectivity. The hydrogen flux and selectivity (H2/N2) of SIEP fabricated Pd-Ag membrane with an oxide layer were found to be 25.83 m3/m2-h and 500 respectively at 40 psi and 450 ºC

Study Of Pd-Ag Membranes With An Intermediate Oxide Layer Fabricated By Surfactant Induced Electroless Plating (Siep)

Uses of fossil fuels in transportation and power generation release greenhouse gases. Hydrogen has the potential to be an alternative clean energy carrier. Hydrogen fueled proton exchange membrane fuel cell (PEMFC) can be used in transportation and stationary power generation to reduce greenhouse gas emissions. However, high purity hydrogen is required for PEMFC. In the current work, dense Pd-Ag composite membranes with an oxide layer on microporous stainless steel substrate (MPSS) were fabricated by surfactant induced electroless plating (SIEP) process for hydrogen separation. Prior to palladium/silver metal deposition, the MPSS disc was oxidized in stagnant air at 500 ºC for 18 h. A cationic surfactant, dodecyl trimethyl ammonium bromide (DTAB) was used in Pd- and Ag-bath for the sequential deposition of metals on MPSS substrates to remove the gas bubbles (N2 and NH3) produced during electroless plating. In this work, 4 CMC and 0.3 CMC (1 CMC = 15.6 mM) of DTAB were used in Pd- and Ag-bath respectively. Addition of a high amount of DTAB leads non-uniform Ag deposition and takes longer time to fabricate defect free Pd-Ag membrane. However, the average particle sizes were found to be 1.4 μm to 2.5 μm, which were relatively larger than the Pd-Ag film particle size using 4 CMC of DTAB in both Pd- and Ag-bath. Morphological features of the fabricated Pd-Ag membranes at pre- and post-annealing conditions were studied by using SEM, XRD, and EDS. The Pd-Ag membrane with an oxide layer showed higher permeability and selectivity in comparison to the membrane without oxide layer. However, at elevated temperature (550 ºC) the membrane showed a sharp decline in selectivity. The hydrogen flux and selectivity (H2/N2) of SIEP fabricated Pd-Ag membrane with an oxide layer were found to be 25.83 m3/m2-h and 500 respectively at 40 psi and 450 ºC

Recent progress on perovskite materials in photovoltaic and water splitting applications

Abstract Both inorganic and hybrid (organo-inorganic) perovskite materials are potential candidates as photocatalysts for use in both photovoltaic (PV) and photocatalytic water splitting applications. Currently, research has been focused on specifically designing perovskite materials so they can harness the broad spectrum of the visible light wavelength. Inorganic perovskites such as titanates, tantalates, niobates, and ferrites show great promise as visible light-driven photocatalysts for water splitting, whereas hybrid perovskites such as methylammonium lead halides reveal unique photovoltaic and charge transport properties. The main objective of this article is to examine the progress on some recent research on perovskite nanomaterials for both solar cell and water splitting applications. This mini review paper summarizes some recent developments of organic and inorganic perovskite materials (PMs) and provides useful insights for their future improvement

Bioinspired study of energy and electron transfer in photovoltaic system

This study focuses on understanding the fundamentals of energy transfer and electron transport in photovoltaic devices with uniquely designed nanostructures by analysing energy transfer in purple photosynthetic bacteria using dye-sensitised solar cell systems. Förster resonance energy transfer between the xanthene dye (donor of energy) and a new polymethine dye (acceptor of energy) was studied in dye-sensitised solar cells, which leads to a doubling of energy conversion efficiency in comparison to the cell with only the polymethine dye. The electron transport in the two different nanostructures of zinc oxide (nanorods and nanosheets) was investigated by spectroscopic methods (UV-vis spectrometer, time-resolved photoluminescence spectroscopy) and electrochemical potentiostat methods. The nanosheet structure of zinc oxide showed high short circuit current and long diffusion length. This fundamental study will lead to efficient artificial photosystem designs

Relaxing music reduces blood pressure and heart rate among pre-hypertensive young adults:A randomized control trial

Prevalence of pre‐hypertension is higher among young adults and may increase the risk for hypertension and cardiovascular morbidity. Music therapy has been investigated to reduce the blood pressure in the hypertensive population; however, its efficacy on blood pressure in pre‐hypertensive young adults is not known. Thirty pre‐hypertensive (systolic blood pressure [SBP] = 120‐139 mmHg and diastolic blood pressure [DBP] = 80‐89 mmHg) young adults were recruited and randomly assigned into two groups. Music group (N = 15) received music therapy by passive listening to music for 30 minutes/day, 5 days/week for 4 weeks, along with Dietary Approaches to Stop Hypertension (DASH) eating plan (a diet rich in fruits and vegetables, low‐fat dairy or unsaturated fat) and limit the daily sodium intake less than 100 mmol/day. The control group (N = 15) practiced only DASH eating plan and sodium restriction. The SBP, DBP, and heart rate (HR) were measured before and after 4 weeks of intervention. There was a significant reduction in SBP (8.73 mmHg, p < .001) and HR (6.42 beats/minute, p = .002); however, the reduction in DBP (1.44 mmHg, p = .101) was not statistically significant in the music group. Control group did not exhibit any significant reduction in SBP (0.21 mmHg, p < .836), DBP (0.81 mmHg, p < .395) and HR (0.09 beats/minute, p < .935). In conclusion, music therapy reduced significantly SBP and HR suggesting that it could be a promising tool to prevent the progression of pre‐hypertension toward hypertension among young adults

Effectiveness of high-intensity interval training and continuous moderate-intensity training on blood pressure in physically inactive pre-hypertensive young adults

The likelihood of pre-hypertensive young adults developing hypertension has been steadily increasing in recent years. Despite the fact that aerobic exercise training (AET) has demonstrated positive results in lowering high blood pressure, the efficacy of different types of AET among pre-hypertensive young adults has not been well-established. The objective of this study was to evaluate the effectiveness of high-intensity interval training (HIIT) and continuous moderate-intensity training (CMT) on the blood pressure (BP) of physically inactive pre-hypertensive young adults. In total, 32 adults (age 20.0 ± 1.1 years and BMI 21.5 ± 1.8) were randomly assigned to three groups: HIIT, CMT and control (CON). The HIIT and CMT groups participated in 5 weeks of AET, while the CON group followed a DASH diet plan only. The HIIT protocol consisted of a 1:4 min work to rest ratio of participants, at an 80–85% heart rate reserve (HR-reserve) and a 40–60% HR-reserve, respectively, for 20 min; the CMT group exercised at 40–60% of their HR-reserve continuously for 20 min. In both the HIIT and CMT groups, systolic blood pressure (SBP) (3.8 ± 2.8 mmHg, p = 0.002 vs. 1.6 ± 1.5 mmHg, p = 0.011) was significantly reduced, while significant reductions in the diastolic blood pressure (DBP) (2.9 ± 2.2 mmHg, p = 0.002) and mean arterial pressure (MAP) (3.1 ± 1.6 mmHg, p < 0.0005) were noted only in the HIIT group. No significant differences in SBP (−0.4 ± 3.7 mmHg, p = 0.718), DBP (0.4 ± 3.4 mmHg, p = 0.714), or MAP (0.1 ± 2.5 mmHg, p = 0.892) were observed in the CON group. Both HIIT and CMT decreased BP in physically inactive pre-hypertensive young adults; however, HIIT yielded more beneficial results in terms of reducing the SPB, DBP and MAP

Association between depressive symptoms of mothers and eating behaviors of school-going children in Urban Bangladesh: A cross-sectional study

Abstract Objective This study aimed to investigate the association between depressive symptoms among mothers and the eating behaviors of their school-going children in Urban Bangladesh. Materials and methods This analytical cross-sectional study was conducted in the context of the urban area of Bangladesh. A multistage sampling technique was applied to select 324 children’s mothers in Dhaka City. Data were collected from both city corporation settings in Dhaka, Bangladesh. Semi-structured questionnaires were used in this study. We estimated the depressive symptoms among mothers using the Zung Self-Rating Depression Scale. We examined the association of mothers of school-going children’s socio-demographic variables and eating behaviors of school-going children with their mother’s depression by using chi-square and evaluating the impact of these variables on mothers’ depression through univariate and multivariate binary logistic regression. Results In our study, 57.7% of the mothers of school-going children had depressive symptoms, and 42.3% had no depressive symptoms. The study explored that consuming fewer vegetables (AOR = 0.237, 95% CI: 0.099–0.569), taking fewer fruits (AOR = 0.177, 95% CI: 0.093–0.337), and interestingly, taking fast food less than 4 days per week (AOR = 3.024, 95% CI: 1.517–6.031) were significantly associated with mothers’ depressive symptoms. Conclusion Mothers with depressive symptoms of school-going children in Dhaka city are alarmingly high as a grave concern. The eating behaviors of children are associated with their mothers’ depressive symptoms. With an aim to build rigorous awareness on depression and child’s healthy eating behaviors, it is imperative to arrange health education and awareness related programs

Knowledge, attitudes, and practices of female health care service providers on female genital mutilation in Somalia:A cross-sectional study

Background: Despite a strong international standpoint against female genital mutilation, the prevalence of female genital mutilation in Somalia is extremely high. Objectives: This study assessed the knowledge, attitude, and practice of female genital mutilation among female health care service providers in order to formulate appropriate policies and programs to eliminate this harmful practice. Design: Facility-based cross-sectional survey conducted in 2019 among female doctors and nurses working in Banadir Hospital, Mogadishu, Somalia. Methods: A total of 144 female health care service providers were randomly selected, and data were collected through a pre-tested, semi-structured questionnaire. Quantitative data were analyzed by using the statistical software SPSS (Version 21), and qualitative data were analyzed thematically in accordance with the objectives of the study. Results: The study found that about three-fifths of the respondents had undergone some forms of female genital mutilation during their life. An overwhelming majority believed that female genital mutilation practices were medically harmful, and a majority of them expressed their opinion against the medicalization of the practice of female genital mutilation. The study also observed a significant association between participants’ age and their negative attitudes regarding the legalization of female genital mutilation. Conclusion: Health care service providers’ effort is critical to eliminating this harmful practice from the Somalian society. Strong policy commitment and a comprehensive health-promotion effort targeting the parents and community leaders are essential to avert the negative impact of female genital mutilation.</p

Bioinspired study of energy and electron transfer in photovoltaic system

<p>This study focuses on understanding the fundamentals of energy transfer and electron transport in photovoltaic devices with uniquely designed nanostructures by analysing energy transfer in purple photosynthetic bacteria using dye-sensitised solar cell systems. Förster resonance energy transfer between the xanthene dye (donor of energy) and a new polymethine dye (acceptor of energy) was studied in dye-sensitised solar cells, which leads to a doubling of energy conversion efficiency in comparison to the cell with only the polymethine dye. The electron transport in the two different nanostructures of zinc oxide (nanorods and nanosheets) was investigated by spectroscopic methods (UV-vis spectrometer, time-resolved photoluminescence spectroscopy) and electrochemical potentiostat methods. The nanosheet structure of zinc oxide showed high short circuit current and long diffusion length. This fundamental study will lead to efficient artificial photosystem designs.</p