181 research outputs found
Electrochemical Synthesis of Electrocatalysts Ni-Fe, Ni-Co, Co-Fe double and Ni-Co-Fe Triple Hydroxides for Efficient Water Splitting to Oxygen and Hydrogen
In this study we have electrochemically fabricated the naturally abundant and stable electrocatalysts Ni-Fe, Ni-Co, Co-Fe-double hydroxides and Ni-Fe-Co-triple hydroxides, for efficient splitting of water to oxygen and hydrogen. Oxygen-evolution reaction (OER) activity of these electrocatalysts electrodeposited on different substrates were examined in an alkaline solution of potassium (KOH). The substrates used were Ni-foam, electrodeposited Ni-Co-oxide on Ni-foam and pressed porous Ni-Co oxide under varying electrodeposition bath composition, electrodeposition time under potential and current controls. The results clearly showed the pronounced effect of substrate on the electro-catalytic activity of these double and triple hydroxides. The synergetic effect of multiple hydroxides and the substrate is responsible for such enhanced electrocatalytic activity. We found that Ni-Fe-Co-triple hydroxide electrodeposited for total of 10 min under potential control at – 1.0/SCE on pressed porous Ni-Co-oxide sheet acted as an exceptional electrocatalyst for OER during water splitting reaction. This electrocatalyst generated a current density of ~ 100.0 mA cm-2 at an oxygen overpotential of 0.270 volt (= 1.5 V vs RHE) in 1.0 M KOH at electrolyte temperature of 25oC. However, the triple hydroxide deposited for 7 min generated 81.0 mA cm-2 at the same overpotential and electrolyte temperature. However, among the double and triple hydroxides deposited on pressed porous Ni-Co oxide substrate under current control at – 250 mA/cm2 for 100 sec, the Co-Fe double hydroxide showed better performance generating a current density of ~ 27.0 mA/cm2 at an oxygen overpotential of 0.270 volt (= 1.5 V vs RHE) in 1.0 M KOH electrolyte at room temperature. Thus, indicating that the activity of double or triple hydroxides synthesized under potential control electrodeposition were found higher compared to samples synthesized by current control perhaps due to too thinner film formation in100 sec deposition time in the later
Remediation of soil contaminated by Salmonella enterica to expedite plant or replant of vegetables
Salmonella enterica is an important bacterial pathogen causing disease outbreaks associated with fresh produce. Improperly composted animal manure is a common environmental source of many enteropathogens in Australia. This study investigated methods for remediating Salmonella-contaminated soil by assessing the effect of environmental factors and soil type on the survival of Salmonella. Four Salmonella serovars were incubated at three temperatures (5, 21 and 37°C) under two moisture regimes (constant and fluctuating) and using two soil types (clay loam and coarse sand) with or without chicken manure in a microcosm pot trial. The survival of Salmonella was low under the following environmental conditions: coarse sand, high temperature, fluctuating moisture regimes, absence of manure. In the field study, soil deliberately inoculated with Salmonella was treated with soil solarisation and three low-residue cover crops to test potential remediation methods. In clay loam, Salmonella declined to below the quantitative limit of detection (LOD) in the control treatment after 105 days indicating natural die off of the pathogen. In coarse sand, Salmonella counts were below the LOD 14 days after inoculation. There was no difference among either cover crop alone or cover crop-solarisation treatments in hastening the decline of Salmonella. However, solarisation alone influenced the decline of Salmonella so it was below the LOD after 56 days. Information from microcosm pot trials and the field study indicated that an exclusion period of more than 90 days between application of untreated manure and crop harvest is required for clay soil. It was concluded that black plastic can be used as a solarisation treatment to remediate Salmonella-contaminated soil and that further research is warranted to exploit the potential of cover crops for their biocidal activity in suppressing Salmonella in the field
Perceived Differences between Male and Female Managers
In the past few decades, the number of women in leadership positions has been increasing, which is a sign of progressive social change. But there is still a gender imbalance in top leadership positions. There are various reasons why women are not in top leadership positions. Therefore, to see the current level of female and male leadership, 26 female and 29 male leaders were selected from seven zone department offices. 14 are zone department heads and 41 are team leaders. The quantitative data were analysed using a descriptive explanatory design, with mean, and inferential analyses using ANCOVA, while the qualitative data were analysed using content analysis. According to the results of the study, in the quantitative analysis, there is no significant difference between male and female leadership; based on the result of ANCOVA P = 0.396 is greater than 0.05; both males and females show transactional leadership as male = 37.5% while the female is 38.1%. Therefore, it is not gender that affects management processes; it is the individual's ability to know the appropriate and effective way of management. So, the only noticeable difference is society's perception and lack of trust in female leadership. Social organization is dominated by men. They think that men represent the "norm" better, but women are inferior and unable to lead independently, thus, a deep awareness of society must be created. Keywords:Leadership, Characteristics of leaders, gender role, the perceived difference DOI: 10.7176/EJBM/14-15-03 Publication date:August 31st 202
Stillbirths and hospital early neonatal deaths at Queen Elizabeth Central Hospital, Blantyre-Malawi
<p>Abstract</p> <p>Background</p> <p>Much of the data on still births and early neonatal deaths from resource-limited settings are obtained via maternal recall from national or community level surveys. While this approach results in useful information to be obtained, often such data suffer from significant recall bias and misclassification. In order to determine the prevalence of stillbirths (SB), early hospital neonatal death (EHND) and associated factors in Blantyre, Malawi, a prospective study of pregnant and post-natal women was conducted at the Queen Elizabeth Central Hospital (QECH), Malawi.</p> <p>Methods</p> <p>A prospective observational study was conducted between February 1, 2004 and October 30, 2005. Consecutive women attending the hospital for delivery were recruited. Data were collected on the health status of the fetus on admission to labor ward and immediately after delivery, whether alive or dead. Gestational age (GA) and birth weight (BW) and sex of the newborn were also noted. Similar data were also collected on the live births that died in the delivery room or nursery. Data were analyzed using SPSS (Statistical Package for the Social Sciences) statistical package.</p> <p>Results</p> <p>A total of 10,700 deliveries were conducted during the 12 months study period and of these deliveries, 845 (7.9%) were SB and EHND. Stillbirths comprised 3.4% of all deliveries; 20.2% of the ante-partum deaths occurred before the mother was admitted to the labor ward while a slightly higher proportion (22.7%) of fetal loss occurred during the process of labor and delivery. Fifty-sex percent of the perinatal deaths (PD) were EHND. The mean gestational age for the perinatal deaths was 34.7 weeks and mean birth weight was 2,155 g (standard deviation = 938 g). The majority, 468 (57.8%) of the perinatal deaths were males and 350 (43.2%) were females. Many of the perinatal deaths (57.9%) were deliveries between gestational ages of 20 and 37 weeks. Most (62.7%) of the mothers with a perinatal death had experienced a previous similar incident.</p> <p>Conclusion</p> <p>About 3.4% of all pregnant mothers past 20 weeks of gestation ended up in delivering a stillbirth; another 4.4% of the live births died before discharge from hospital, thus, 7.9% of pregnancy loss after 20 weeks (or 500 g estimated weight) of gestation. This is a higher loss when compared to international and regional data. We recommend attention be given to these unfavorable outcomes and preventive measures or intervention for preventable causes be considered seriously. These measures could include the provision of emergency obstetric care, improving access to deliveries by health professionals and resourcing of health facilities such that neonatal viability is promoted.</p
Design of Dual and Swing Restored Complementary Pass Transistor Logic for Low Power Ripple Carry Array Multiplier
In a conventional array multiplier many number of CMOS structures are used in designing. Here this paper presents a multiplier that uses an alternative internal logic structure in designing. The project uses pass transistors logic designs leading to reduction of power usage
Parents' views on play and the goal of early childhood education in relation to children's home activity and executive functions:A cross-cultural investigation
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