ABSTRACT
The oxygen evolution reaction (OER) is a key reaction in the production of green hydrogen by water electrolysis. In alkaline media, the current state of the art catalysts used for the OER are based on non-noble metal oxides. However, despite their huge potential as OER catalysts, these materials exhibit various disadvantages including lack of stability and conductivity that hinder the wide-spread utilization of these materials in alkaline electrolyzer devices. This study highlights the innovative chemical functionalization of a mixed copper cobalt hydroxide with the V2CT x MXene to enhance the OER efficiency, addressing the need for effective electrocatalytic interfaces for sustainable hydrogen production. The herein synthesized CuCo@V2CT x electrocatalysts demonstrate remarkable activity, outperforming the pure CuCo catalysts for the OER and moreover show increased efficiency after 12 hours of continuous operation. This strategic integration improved the water oxidation performance of the pure oxide material by improving the composite's hydrophilicity, charge transfer properties and ability to hinder Cu leaching. The materials were characterized using an array of materials characterization techniques to help decipher both structure of the composite materials after synthesis and to elucidate the reasoning for the OER enhancement for the composites. This work demonstrates the significant potential of TMO-based nanomaterials combined with V2CT x for advanced innovative electrocatalytic interfaces in energy conversion applications.
ABSTRACT
Transparent conductors (TCs) represent key components in many applications from optoelectronic devices to electromagnetic shielding. While commercial applications typically use thin films of indium tin oxide, this material is brittle and increasingly scarce, meaning higher performing and cheaper alternatives are sought after. Solution-processible metals would be ideal owing to their high conductivities and printability. However, due to their opacity to visible light, such films need to be very thin to achieve transparency, thus limiting the minimum resistance achievable. One solution is to print metallic particles in a grid structure, which has the advantages of high tunable transparency and resistance at the cost of uniformity. Here, we report silver nanosheets that have been aerosol jet printed into grids as high-performance transparent conductors. We first investigate the effect of annealing on the silver nanosheets where we observe the onset of junction sintering at 160 °C after which the silver network becomes continuous. We then investigate the effect of line width and thickness on the electrical performance and the effect of varying the aperture dimensions on the optical performance. Using these data, we develop simple models, which allow us to optimize the grid and demonstrate a printed transparent conductor with a transmittance of 91% at a sheet resistance of 4.6 Ω/sq.
ABSTRACT
African-American men continue to bear a disproportionate share of the burden of health disparities, in general, and chronic diseases, in particular. The Men of Color Health Awareness (MOCHA) Moving Forward study seeks to determine the effectiveness of an innovative, community-driven program to improve the health and quality of life of low-income African-American men between the ages of 35 to 70 years by reducing identified social risk factors for chronic disease for these men. The project uses digital storytelling (DST) to encourage African-American men to tell their stories, especially related to stress, gender role stereotypes, and mental and physical health and well-being. Thirty-six men were recruited to participate in one of four DST workshops, which resulted in each participant creating a 2- to 3-minute digital story. In this article, we describe and analyze three salient ethical dilemmas that arose in conducting the Men of Color Health Awareness Moving Forward study DST workshops with African-American men. The dilemmas can be traced to the distinct purposes for which DST can be used, data collection or intervention development, and the trade-offs between protecting and patronizing participants. We discuss potential ways to resolve or circumvent the identified issues.
Subject(s)
Black or African American , Health Promotion/organization & administration , Narration , Poverty , Adult , Aged , Communication , Humans , Male , Middle Aged , Quality of LifeABSTRACT
African American men continue to bear a disproportionate share of the burden of disease. Engaging these men in health research and health promotion programs-especially lower-income, African American men who are vulnerable to chronic disease conditions such as obesity and heart disease-has historically proven quite difficult for researchers and public health practitioners. The few effective outreach strategies identified in the literature to date are largely limited to recruiting through hospital clinics, churches, and barbershops. The Men of Color Health Awareness (MOCHA) project is a grassroots, community-driven initiative that has developed a number of innovative outreach strategies. After describing these strategies, we present data on the demographic and health characteristics of the population reached using these methods, which indicate that MOCHA has been highly effective in reaching this population of men.
Subject(s)
Biomedical Research/methods , Black or African American/statistics & numerical data , Health Promotion/methods , Men's Health , Minority Groups/statistics & numerical data , Adult , Black or African American/psychology , Barbering , Humans , Male , Patient Selection , Socioeconomic Factors , United StatesABSTRACT
PURPOSE: There is a dearth of effective, evidence-based programs to reduce chronic disease in low-income African-American men. We report on the results of formative research in the National Institutes of Health (NIH)-funded MOCHA Moving Forward project on factors identified by the participants to drive health disparities. METHODS: Based on individual interviews with 42 middle-aged (40-65 years), low-income African-American men, three themes emerged. RESULTS: First, the results indicate a hierarchy in the perceived relative influence of different factors, with poverty and unemployment perceived to have the most powerful affects. Second, results show that factors in different domains do not operate as discrete independent influences, but rather, interact synergistically. Finally, the findings show how perceived social structural constraints have produced deep cynicism about the future, with notably divergent reactions, producing a sense that there is almost nothing an individual can do, or paradoxically, a greater the sense of personal responsibility. CONCLUSION: The implications of addressing the cascade of social determinants to reduce chronic disease in African-American men are discussed.
Subject(s)
Attitude , Black or African American , Chronic Disease/ethnology , Health Status Disparities , Income , Poverty , Social Determinants of Health , Adult , Aged , Humans , Male , Middle Aged , Qualitative Research , Unemployment , United StatesABSTRACT
Foram analisados, em estudo de Coorte Histórica, os prontuários de 78 pacientes submetidos a cirurgias colorretais eletivas no Serviço de Colo-Proctologia do Hospital Universitário de Florianópolis -SC, no período de janeiro de 1994 a dezembro de 1995. O objetivo foi avaliar os fatores de risco relacionados ao próprio paciente para infecçäo da ferida operatória. O índice geral de infecçäo da ferida nas cirurgias colorretais eletivas foi de trinta e nove, nove por cento, com setenta e um, cinco por cento superficiais e vinte e oito, cinco por cento profundas...
Subject(s)
Humans , Female , Male , Adolescent , Adult , Middle Aged , Colorectal Surgery/adverse effects , Risk Factors , Surgical Wound Infection/complicationsABSTRACT
L'article invite le lecteur a reflechir sur la notion de vulnerabilite indissociable de toute approche du risque. Cette question concerne les regions cotieres, mais de maniere generale tout type de region exposee aux menaces naturelles. Plusieurs exemples, issus de travaux recemment realises dans le domaine des sciences sociales, illustrent l'interet des etudes de vulnerabilite (AU)