This study deals with the extraction and testing of natural cellulose fibers obtained from the barks of Ziziphus nummularia (Burm. f.) Wight & Arn. plants. The extraction of Z. nummularia fibers from its plant bar...
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This study deals with the extraction and testing of natural cellulose fibers obtained from the barks of Ziziphus nummularia (Burm. f.) Wight & Arn. plants. The extraction of Z. nummularia fibers from its plant barks was done by water retting. The extracted fibers were analyzed for their chemical, crystalline, thermal, mechanical, and physical properties. Surface characteristics of the fibers were examined using a scanning electron microscope and an atomic force microscope. The test results showed that cellulose content was 52.34%. The crystalline index was 45.77% whereas the crystallite size was 2.01 nm. Thermogravimetric analysis showed a maximum degradation temperature of 348 degrees C. The morphological properties showed that Z. nummularia fibers had a good surface roughness that helps in forming interlocks with the matrix on its usage in polymer matrix composites.
A well-known cartoon among psychologists and behavior analysts depicts two rats in a Skinner box, leaning over a response lever as one says to the other, "Boy, do we have this guy conditioned, every time I press ...
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A well-known cartoon among psychologists and behavior analysts depicts two rats in a Skinner box, leaning over a response lever as one says to the other, "Boy, do we have this guy conditioned, every time I press the bar down he drops a pellet in." Anyone who has ever conducted an experiment, worked with a client, or taught someone can relate to the cartoon's message of reciprocal control between subject and experimenter, client and therapist, and teacher and student. This is the tale of that cartoon and its impact. It begins mid-20(th)-century at Columbia University, then a hotbed of behavioral psychology, which bears an intimate connection to the cartoon's appearance. The tale expands from Columbia to follow the lives of its creators from their undergraduate days there to their deaths decades later. The infusion of the cartoon into American psychology begins with B. f. Skinner, but, over the years, it also has appeared in introductory psychology textbooks and in iterative form in mass media outlets such as the World Wide Web and magazines like The New Yorker. The heart of the tale, however, was stated in the second sentence of this abstract. The tale ends with a review of how reciprocal relations like those depicted by the cartoon's creators have influenced research and practice in behavioral psychology.
Experimental and numerical investigations have been carried out for performance evaluation of plate heat exchanger (PHE) using CuO-DI water nanofluid at different volume concentrations of (phi = 0, 0.005, 0.01, 0.03, ...
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Experimental and numerical investigations have been carried out for performance evaluation of plate heat exchanger (PHE) using CuO-DI water nanofluid at different volume concentrations of (phi = 0, 0.005, 0.01, 0.03, 0.05, and 0.07) for the Reynolds number, Re = 71-1350, Prandtl number, Pr = 3.18-13.7, and at fixed inlet temperatures of hot and cold fluids Th-i = 60 degrees C and Tc-i = 20 degrees C, respectively. The two main influential thermo-physical properties of the nanofluid, namely, dynamic viscosity and thermal conductivity obtained for various volume fractions at different temperatures, are further utilized for performance analysis of the PHEs. The thermo-hydraulic performance of PHE is evaluated based on the J.f. factor. According to experimental and simulated results, volume concentration, phi = 0.03 is found to be the optimum concentration of nanofluids. The individual correlations for Nusselt number, friction factor, dynamic viscosity, and thermal conductivity in terms of nanofluid volume fraction are proposed based on the experimental results.
In order to promote the widespread use of zinc-air batteries, operating in various extreme temperature regions around the world needs to further improve the cold start capability. It is very important to solve the pro...
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In order to promote the widespread use of zinc-air batteries, operating in various extreme temperature regions around the world needs to further improve the cold start capability. It is very important to solve the problem of cold start by studying the physical phenomena in the battery during cold start and clarifying the mechanism of hindering cold start. In this study, we have researched the internal behavior in zinc-air batteries at different starting currents and temperatures during cold start. Experiments have found that 5 mol/L electrolytes freeze into ice after freezing at -30 degrees C, while 6 to 9 mol/L solutions are still liquid after freezing. At the same electrolyte concentration, the lower the temperature, the higher the open-circuit voltage. The results show that the temperature has no obvious effect on the discharge voltage at low-current density, but has a great effect at high-current density. After several freeze-thaw cycles, cracks appear on the surface of the catalyst layer, which has a negative effect on the hydrophobicity of the gas diffusion layer. Additives can improve the interfacial ion transport performance and provide a direction for future additive research, which is very important for the practical application of water-based zinc-air batteries.
The fruit fly, Drosophila melanogaster, is a simple and powerful model organism. It has played a critical role over more than a century, for example in establishing the field of genetics, and in foundational insights ...
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The fruit fly, Drosophila melanogaster, is a simple and powerful model organism. It has played a critical role over more than a century, for example in establishing the field of genetics, and in foundational insights into the molecular basis of development. from the 1930s until today, researchers at the University of Edinburgh have used Drosophila to tackle questions in basic and biomedical science. Here the history of the initial decades of this research is explored, beginning with the introduction of Drosophila research to Edinburgh by francis Albert Eley Crew, in the newly established Institute of Animal Genetics. This period of research includes the discovery that chemicals can cause genetic mutation. This was demonstrated by research of the effects of mustard gas on flies by Charlotte Auerbach and colleagues, guided by the future Nobel laureate Hermann Muller. Drosophila research was also formative in Conrad Hal Waddington's conceptual thinking about developmental biology, including in his vision of the epigenetic landscape. This holistic, systems-level view of the control of development was far before its time and has continued to be influential to this day in our conceptualisation of developmental biology and in the increasingly important field of systems biology. Waddington's experiments with Drosophila in Edinburgh also gave rise to the evolutionary concept of genetic assimilation, in which an environmentally induced phenotype subsequently becomes genetically encoded.
Organic memristors with homogeneous resistive switching behaviors can emulate the functionalities of biological synapses, making them promising candidates for use in brain-inspired neuromorphic computing. Among variou...
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Organic memristors with homogeneous resistive switching behaviors can emulate the functionalities of biological synapses, making them promising candidates for use in brain-inspired neuromorphic computing. Among various environmental parameters, humidity affecting device operational stability is a critical issue that organic memristors face in practical applications. A high humidity resistant organic memristor is demonstrated here using a small molecule material f16CuPc. Unencapsulated devices show excellent moisture stability, maintaining reliable memristive switching behavior after 1 year of exposure to air at 60% high relative humidity and remaining operational when immersed in water for 96 h. A proton conduction mechanism is discovered responsible for the resistive switching effect. The continuously adjustable conductance in f16CuPc-based memristive devices enables the mimicking of biological synapse functions. These results open up a path to a humidity tolerant neuromorphic computing system based on high humidity resistant artificial synapse devices.
The impact offungicides on the head blight (fHB) development disease index, percent spike harvest index (SHI), and deoxynivalenol (DON) accumulation in wheat kernels under field conditions was evaluated after artific...
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The impact offungicides on the head blight (fHB) development disease index, percent spike harvest index (SHI), and deoxynivalenol (DON) accumulation in wheat kernels under field conditions was evaluated after artificial spike inoculation with fusarium culmorum (S-14). The trial was carried out using commercially available fungicides and a sensitive cultivar of bread wheat (flamura-85) in a field of a wheat producer located in the Trakya region of Turkey. fungicides were applied at the beginning of anthesis (ZGS 61), 48 hours after the inoculation with the pathogen. Disease index was determined 10 days and 14 days post-inoculation. The application offungicides containing tebuconazole, thiophanate methyl plus tetraconazole and prothioconazole plus trifloxystrobin reduced the fHB disease and increased kernel number, spike weight, and kernel weight, as compared to the inoculated/non-fungicide control. The efficacy of tebuconazole and of prothioconazole plus trifloxystrobin was higher than that of thiophanate methyl plus tetraconazole on fHB disease severity, percent spike harvest index (SHI), and DON accumulation in wheat kernels.
Objectives: During the early months of the COVID-19 pandemic, virtual and telephone visits rapidly replaced most in-person care within the Veterans Health Administration (VA) to reduce the virus spread. To address the...
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Objectives: During the early months of the COVID-19 pandemic, virtual and telephone visits rapidly replaced most in-person care within the Veterans Health Administration (VA) to reduce the virus spread. To address the emerging mental health needs of older Veterans (e.g., social isolation) in the context of chronic underlying mental health needs (e.g., trauma), we developed an 8-week virtual group treatment manual. This article describes the results from a survey of geriatric mental health clinicians who used the COVID group manual to determine its acceptability and feasibility in these settings. Methods: Clinicians across three VA integrated care settings (home-based primary care, community living centers, and geriatric primary care) were surveyed about their experiences implementing this treatment (n = 21). Results: Clinicians found this intervention to be effective with their patients and useful and adaptable beyond the early pandemic period. Conclusions: This group teletherapy intervention was feasible and acceptable when treating Veterans in integrated geriatric healthcare settings. Despite technical challenges experienced by older Veterans, clinicians found this manual to be effective in addressing COVID-related worry and social isolation. Clinical Implications: This rapid response manual has remained clinically useful in geriatric mental health care settings beyond the initial weeks of the pandemic.
friedrich A. Hayek thoroughly criticizes labor unions in Sect. 18 of The Constitution of Liberty published in 1960 and insists in the same section that closed-shop contracts should be illegal. He also views yellow-dog...
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friedrich A. Hayek thoroughly criticizes labor unions in Sect. 18 of The Constitution of Liberty published in 1960 and insists in the same section that closed-shop contracts should be illegal. He also views yellow-dog contracts, which were designed as countermeasures against the labor unions, as illegal. However, it has been pointed out that, according to Hayek's social philosophy, neither the closed-shop contract nor the yellow-dog contract should be seen as legal issues, as they are based on free will between the parties and have no compulsory elements. The key to solving this dilemma is in understanding how Hayek views the core concepts of the U.S. Antitrust Law, namely, restraint of trade and monopoly. The aim of this article is to examine the theoretical structure of Hayek's arguments on those types of contracts, freedom and coercion, the 'restraint of trade' doctrine, and the rule of law. It addresses the important common law issues offreedom, coercion, monopoly, restraint of trade, and the rule of law.
Objective Community college students engage in more risky sexual behavior compared to their four-year counterparts, yet have access to fewer reproductive health services. The study's purpose was to examine whether...
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Objective Community college students engage in more risky sexual behavior compared to their four-year counterparts, yet have access to fewer reproductive health services. The study's purpose was to examine whether California Community College student health centers' participation in family PACT, a state publicly-funded family planning program, increased reproductive health services to community colleges students. Participants California community college student health centers. Methods Bivariate analyses of student health centers with and without family PACT participation and qualitative analysis offive participating campuses. Results Among the 60 colleges in the study, 25 student health centers participated in the family PACT program. family PACT campuses reported greater provision of sexual and reproductive health services and higher levels of staffing and revenue. Conclusions Key benefits offamily PACT participation among community colleges include expansion of sexual and reproductive health services to an underserved population and increased student health centers' financial sustainability.
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