Preparation and characteristics of the sulfonated chitosan derivatives electrodeposited onto 316l stainless steel surface

In order to ameliorate the properties of corrosion resistance and achieve applications in anti-biofouling of 316L stainless steel (SS), a sulfated derivative of chitosan was deposited onto stainless steel surface by an electrochemical method. In detail, chitosan-catechol (CS-CT) was synthesised in the hydrochloric acid solution by the Mannich reaction and then electrodeposited on the surface of the polished 316L stainless steel. The chitosan-catechol deposited SS sample was further modified with maleic anhydride and sulfite. The grafting progress was monitored by FTIR, UV spectrophotometer and X-ray photoelectron spectroscopy. Hydrophilicity and corrosion resistance of modified SS were characterized by water contact angle measurements, Tafel curves and electrochemical impedance spectroscopy. The morphology of the SS surface before and after the modification was investigated by atomic force microscopy and scanning electron microscope. Further, the anti-biofouling performance in terms of the anti-adsorption protein and anti-bacteria effects of all modified SS samples were estimated, and the modified 316L exhibits the capability of lower protein adsorption and improved antibacterial effect.info:eu-repo/semantics/publishedVersio

Structural Sexism in the United States and Patterns of Women's Alcohol Use in Recent Decades

Alcohol consumption is a leading cause of morbidity and premature mortality. In the United States, consumption remains highly prevalent, and certain subgroups have been increasing alcohol risks in recent decades. Among these are women in the mid-life, who have increased rates of both alcohol consumption (vs. abstention) and binge drinking (i.e., multiple drinks in a setting). Women’s alcohol use has increased concurrent with social and economic gains. These gains in women’s social and economic status are indicative of broader declines in structural sexism, a macro-level, systematic source of gender inequality. The objective of this dissertation is to examine the associations between state-level structural sexism (e.g.., social, political, and economic gender inequality) and patterns of women’s alcohol consumption. This dissertation is presented in five chapters: first, an introduction; second, a narrative historical review of the relationship between structural sexism in the United States and women’s health outcomes, with a lens towards understanding the theoretical and epidemiologic sources of conflicting study findings; third, an empirical study of the relationship between state-level structural sexism and both alcohol consumption and binge drinking among women in the mid-life in recent cohorts; fourth, an empirical study examining structural sexism as a source of heterogeneity for relationships between women’s social positions—namely, their occupational characteristics—and both alcohol consumption and binge drinking; fifth, a discussion of findings and implications for future research. Materials and methods The narrative literature review drew from empirical studies in public health, criminology, and sociology (N=43 studies). The two empirical aims used longitudinal data from Monitoring the Future (MTF), a national survey examining substance use throughout young adulthood, using data from cohorts who were high school seniors between 1988-2006. For both empirical aims, I measured structural sexism using a factor-analytically derived score based on state-level social and economic indicators of gender inequality, and assessed occasions of alcohol consumption and probability of binge drinking as study outcomes. Both studies used three-level multilevel models to estimate associations between structural sexism and each alcohol outcome. The first empirical aim included a sample of 23,862 women surveyed between 1988-2016, and beyond the marginal association also tested the role of three mediators: depressive symptoms, college completion, and restrictive alcohol norms. The second empirical aim included a sample of 16,571 women in the MTF follow-up surveys between 1989-2016, and examined whether associations among work status, high-status careers, occupational gender composition, and both alcohol outcomes varied across levels of structural sexism using interaction models between occupational characteristics and state structural sexism. Results The review identified the divergent theoretical frameworks and measurement invariance as the most pressing threats to reconciling competing findings. In the review I also observed a dearth of empirical studies relating structural sexism to any behavioral health outcomes, including alcohol use. In the first empirical study, I demonstrated that women living in states with lower levels of structural sexism evidenced increases in both occasions of alcohol consumption (RR: 0.974, 95% CI: 0.971, 0.976) and probability of binge drinking (OR: 0.917, 95% CI: 0.909, 0.926); I showed that this relationship was specific to women (i.e., it was less pronounced among men) and that mediators of this relationship included increases in college completion and decreases in restrictive alcohol norms. In the second empirical study, I found that working women evidenced higher frequencies of alcohol consumption and higher probabilities of binge drinking than non-working women, and that these differences were most pronounced among women in low-sexism environments. At the lowest level of structural sexism, employed women reported higher occasions of consumption (2.61, 95% CI 2.57, 2.64) then unemployed women (2.32, 95% CI 2.27, 2.37). I also found that women in high-status occupations reported more occasions of alcohol consumption than those in low-status occupations, but only in low-sexism environments. Conclusions Lower levels of structural sexism are related to increases in both alcohol consumption and binge drinking among women. In low-sexism environments, working and belonging to a high-status career increases women’s alcohol use. Increases in women’s equality are positive and important social forces, but have conferred new acceptability of alcohol use that has implications for women’s health

Techno-economic analysis of heat pumping technology for oleochemical fatty acid fractionation

Distillation unit is often known as a major energy consumer in chemical refineries. Recent researches have shown an increased interest in heat pumping technology. So far, previous studies of heat pump integrated column have not dealt with industrial oleochemical separation. The aim of this research paper has therefore been to investigate the implications of using heat pumping technology on oleochemical fractionation. This work takes the form of an industrial case-study of palm kernel oil (PKO) fatty acid fractional distillation. Two different arrangements of mechanical vapour recompression (MVR); namely direct vapour recompression (VRC) and bottom flashing heat pump (BFHP), were introduced to the process and their performances were assessed for technological efficacy as well as cost effectiveness. All simulations were carried out using Aspen Plus process simulator and UNIQUAC was chosen as the most suitable thermodynamic package. Economic analysis in terms of capital expenses (CAPEX) and operational expenses (OPEX) was evaluated. Though both MVR systems have shown relative reduction in energy load, however the CAPEX performance demonstrated in this study was not very appealing due to the additional equipment to satisfy the energy requirement. One anticipated finding was that the OPEX for the VRC showed only 50% from the conventional column (CC). On the contrary, the BFHP was ruled out for its CAPEX and OPEX, which showed twice as much as the CC

Evidence for HIV transmission across key populations: a longitudinal analysis of HIV and AIDS rates among Black people who inject drugs and Black heterosexuals in 84 large U.S. metropolitan areas, 2008–2016

Purpose: To assess cross-population linkages in HIV/AIDS epidemics, we tested the hypothesis that the number of newly diagnosed AIDS cases among Black people who inject drugs (PWID) was positively related to the natural log of the rate of newly diagnosed HIV infections among Black non-PWID heterosexuals in 84 large U.S. metropolitan statistical areas (MSAs) in 2008–2016. Methods: We estimated a multilevel model centering the time-varying continuous exposures at baseline between the independent (Black PWID AIDS rates) and dependent (HIV diagnoses rate among Black heterosexuals) variables. Results: At MSA level, baseline (standardized β = 0.12) Black PWID AIDS rates and change in these rates over time (standardized β = 0.11) were positively associated with the log of new HIV diagnoses rates among Black heterosexuals. Thus, MSAs with Black PWID AIDS rates that were 1 standard deviation= higher at baseline also had rates of newly diagnosed HIV infections among Black non-PWID heterosexuals that were 10.3% higher. A 1 standard deviation increase in independent variable over time corresponded to a 7.8% increase in dependent variable. Conclusions: Black PWID AIDS rates may predict HIV rates among non-PWID Black heterosexuals. Effective HIV programming may be predicated, in part, on addressing intertwining of HIV epidemics across populations

Police killings of Black people and rates of sexually transmitted infections: A cross-sectional analysis of 75 large US metropolitan areas, 2016

Objectives Emerging literature shows that racialised police brutality, a form of structural racism, significantly affects health and well-being of racial/ethnic minorities in the USA. While public health research suggests that structural racism is a distal determinant of sexually transmitted infections (STIs) among Black people, no studies have empirically linked police violence to STIs. To address this gap, our study measures associations between police killings and rates of STIs among Black residents of US metropolitan statistical areas (MSAs). Methods This cross-sectional ecological analysis assessed associations between the number of Black people killed by police in 2015 and rates of primary and secondary syphilis, gonorrhoea and chlamydia per 100 000 Black residents of all ages in 2016 in 75 large MSAs. Multivariable models controlled for MSA-level demographic and socioeconomic characteristics, police expenditures, violent crime, arrest and incarceration rates, insurance rates and healthcare funding. Results In 2015, the median number of Black people killed by police per MSA was 1.0. In multivariable models, police killings were positively and significantly associated with syphilis and gonorrhoea rates among Black residents. Each additional police killing in 2015 was associated with syphilis rates that were 7.5% higher and gonorrhoea rates that were 4.0% higher in 2016. Conclusions Police killings of Black people may increase MSA-level risk of STI infections among Black residents. If future longitudinal analyses support these findings, efforts to reduce STIs among Black people should include reducing police brutality and addressing mechanisms linking this violence to STIs

Towards Carbon Neutral CO2 Conversion to Hydrocarbons

With fossil fuels still predicted to contribute close to 80 % of the primary energy consumption by 2040, methods to limit further CO2 emissions in the atmosphere are urgently needed to avoid the catastrophic scenarios associated with global warming. In parallel with improvements in energy efficiency and CO2 storage, the conversion of CO2 has emerged as a complementary route with significant potential. In this work we present the direct thermo‐catalytic conversion of CO2 to hydrocarbons using a novel iron nanoparticle–carbon nanotube (Fe@CNT) catalyst. We adopted a holistic and systematic approach to CO2 conversion by integrating process optimization—identifying reaction conditions to maximize conversion and selectivity towards long chain hydrocarbons and/or short olefins—with catalyst optimization through the addition of promoters. The result is the production of valuable hydrocarbons in a manner that can approach carbon neutrality under realistic industrial process conditions

Production of Crotonaldehyde from Acetaldol

Optimum operating conditions for the production of crotonaldehyde from acetaldol were investigated and the kinetics of the reaction were determined. The most important operating conditions were found to be the cracking time, the pH value of the reaction mixture, and the initial concentration of acetaldol. The order of the reaction was found to be 1.8 with respect to the acetaldol concentration. The kinetic parameters were determined to be 20.583 (m3/kmol)0.8/min for the frequency factor, and 3416.800 kJ/kmol for the activation energy. Copyright © 1994 Publisher John Wiley & Sons, Ltd