676 research outputs found

    Activated Carbons Prepared from Oil Palm Shells: Characterisations and Application for Column Separation of Heavy Metals

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    Wastes from agricultural products are abundant, suitable to be used as precursor for producing activated carbons. These wastes, instead of causing significant disposal problems, can be turned into by-products for industries by utilizing them fur manufacturing activated carbons. Carbonization and activation processes were done in the Tubular Carbolite Furnace. N₂ gas was flowed for the first 3 hours followed by CO₂ gas for the next 1 hour on the precursor at the constant temperature of 500°C. Par the H₃PO₄ impregnation, 30 grams of the palm shells were impregnated with 15 ml ofH3P04 and diluted with 100 ml of distilled water to produce 2.2 M H₃PO₄ solution. For the K₃PO₄, 30 grams of palm shells were impregnated with 9 g of K₃PO₄ and diluted with 100 ml of distilled water to produce 9% w/w K₃PO₄ solution. For the KOH impregnation, 30 grams or palm shells were impregnated with 9 g of KOH and diluted with 100 ml of distilled water to produce 9 % w/w KOH solution

    Sphagnum physiology in the context of changing climate: emergent influences of genomics, modelling and host-microbiome interactions on understanding ecosystem function.

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    Peatlands harbour more than one-third of terrestrial carbon leading to the argument that the bryophytes, as major components of peatland ecosystems, store more organic carbon in soils than any other collective plant taxa. Plants of the genus Sphagnum are important components of peatland ecosystems and are potentially vulnerable to changing climatic conditions. However, the response of Sphagnum to rising temperatures, elevated CO2 and shifts in local hydrology have yet to be fully characterized. In this review, we examine Sphagnum biology and ecology and explore the role of this group of keystone species and its associated microbiome in carbon and nitrogen cycling using literature review and model simulations. Several issues are highlighted including the consequences of a variable environment on plant-microbiome interactions, uncertainty associated with CO2 diffusion resistances and the relationship between fixed N and that partitioned to the photosynthetic apparatus. We note that the Sphagnum fallax genome is currently being sequenced and outline potential applications of population-level genomics and corresponding plant photosynthesis and microbial metabolic modelling techniques. We highlight Sphagnum as a model organism to explore ecosystem response to a changing climate and to define the role that Sphagnum can play at the intersection of physiology, genetics and functional genomics

    To ‘Sketch-a-Scratch’

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    A surface can be harsh and raspy, or smooth and silky, and everything in between. We are used to sense these features with our fingertips as well as with our eyes and ears: the exploration of a surface is a multisensory experience. Tools, too, are often employed in the interaction with surfaces, since they augment our manipulation capabilities. “Sketch-a-Scratch” is a tool for the multisensory exploration and sketching of surface textures. The user’s actions drive a physical sound model of real materials’ response to interactions such as scraping, rubbing or rolling. Moreover, different input signals can be converted into 2D visual surface profiles, thus enabling to experience them visually, aurally and haptically

    Preparation and characterization of activated carbon derived from waste rubber tire via chemical activation with ZnCl2: surface area and morphological studies

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    Turning waste to wealth is an important aspect in promoting green technology. In this study, activated carbon from waste rubber tire was prepared using chemical activation (ZnCl2) by way of two-stage activation in self-generated atmosphere method. The preparation parameters examined and compared in this study were activation time, activation temperature, and impregnation ratio. The adsorption of the target pollutant, 2,4-dichlorophenol (DCP), was used to evaluate the efficiency of adsorption capacity of the prepared activated carbon. Results from the experimental work showed that the activated carbon prepared satisfied the Freundlich isotherm and complied with the pseudo-second-order kinetics (not presented here). Other parameters studied, such as the percentage yield of activated carbon, ash, and moisture content and the morphology structure, are presented in this chapter. This study showed that waste rubber tire dehydrated with ZnCl2 with an impregnation ratio of 1:1 and activated at a temperature of 500 °C for 120 min gave the best result (AC5)

    Remediation of anionic dye simulated wastewater using TiO2 as a photocatalyst under various light irradiation wavelength

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    Heterogeneous photocatalytic process employing UV/TiO2 batch photo-reactor system was demonstrated to be effective in the photodegradation of C.I. Reactive Black 5 anionic dye. Various artificial lamps (UV-A, UV-B, UV-C and solar irradiation) were used to activate the TiO2-P25 Degussa photocatalyst. UV-C was found to be the best in degrading RB5 with 100% efficiency at the 25th min with an R2 = 0.9786 according to the first order reaction kinetic model. The effectiveness of UV-C is due to the shorter penetration capability with higher energy photon, so there was more electron-hole pairs available for the target compound. Photodegradation with UV-B was also similarly effective while UV-A and solar irradiations were least effective. Increasing the initial dye concentration reduced the degradation rate due to the inner photon filtering effect by the dye molecules. Since RB5 is anionic dye, by increasing the pH of the system, the degradation rate was reduced to 99.65% in 1 h at pH10. This is due to the electrostatic attraction between the dye molecules and the negatively charged TiO2 particles. Photocatalytic degradation was found to be affected by the pollutant concentration and solution pH which were explored and described in detail in this article

    The Idea Of A Realistic Utopia

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    The purpose of this dissertation is to articulate the proper aims and limits of political philosophy by expanding upon John Rawls’s idea of a realistic utopia and applying it to various debates in contemporary political philosophy. First, I defend the importance of ideal theory in constructing a theory of justice and respond to various critics, such as Amartya Sen and others, who argue that ideal theory is neither necessary nor sufficient for our work to advance justice in society. Second, I argue that empirical facts must be included in our reasoning about fundamental principles of justice, contrary to theorists such as G.A. Cohen who argues that political theorizing should proceed independently of such facts. Finally, I conclude with some reflecting thoughts on the importance of articulating a conception of justice that avoids hopelessly utopian ideals. In doing so, I defend the vision of a realistically utopian society as one that both answers our most fundamental interests and also provides us with the best chance of realizing justice in the world

    Operating parameters and synergistic effects of combining ultrasound and ultraviolet irradiation in the degradation of 2,4,6-trichlorophenol

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    The sonophotodegradation of 2,4,6-trichlorophenol (TCP) in a homogeneous aqueous system was investigated. The effectiveness of sonolytic, photolytic and sonophotolytic oxidation processes in the degradation of aqueous solutions of TCP was investigated by applying ultrasonic waves or ultraviolet radiation or a combination of these two techniques. The optimum operating parameters for the horn-type sonicator and the UV-A lamp were determined along with the effect of temperature on the TCP degradation. It was found that an increase in acoustic intensity and UV lamp intensity was proportional to an increased efficiency of the sonolytic and photolytic degradation of TCP. However, an increase in the solution temperature caused the TCP to evaporate resulting in the first-order kinetic rate showing the presence of a synergistic effect at temperatures between 10 °C and 20 °C, an additive effect at a temperature of 30 °C and an antagonistic effect at temperatures of 40 °C and higher

    Factors Associated with Ever Being HIV-Tested in Zimbabwe: An Extended Analysis of the Zimbabwe Demographic and Health Survey (2010-2011).

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    INTRODUCTION: Zimbabwe has a high human immunodeficiency virus (HIV) burden. It is therefore important to scale up HIV-testing and counseling (HTC) as a gateway to HIV prevention, treatment and care. OBJECTIVE: To determine factors associated with being HIV-tested among adult men and women in Zimbabwe. METHODS: Secondary analysis was done using data from 7,313 women and 6,584 men who completed interviewer-administered questionnaires and provided blood specimens for HIV testing during the Zimbabwe Demographic and Health Survey (ZDHS) 2010-11. Factors associated with ever being HIV-tested were determined using multivariate logistic regression. RESULTS: HIV-testing was higher among women compared to men (61% versus 39%). HIV-infected respondents were more likely to be tested compared to those who were HIV-negative for both men [adjusted odds ratio (AOR) = 1.53; 95% confidence interval (CI) (1.27-1.84)] and women [AOR = 1.42; 95% CI (1.20-1.69)]. However, only 55% and 74% of these HIV-infected men and women respectively had ever been tested. Among women, visiting antenatal care (ANC) [AOR = 5.48, 95% CI (4.08-7.36)] was the most significant predictor of being tested whilst a novel finding for men was higher odds of testing among those reporting a sexually transmitted infection (STI) in the past 12 months [AOR = 1.86, 95%CI (1.26-2.74)]. Among men, the odds of ever being tested increased with age ≥ 20 years, particularly those 45-49 years [AOR = 4.21; 95% CI (2.74-6.48)] whilst for women testing was highest among those aged 25-29 years [AOR = 2.01; 95% CI (1.63-2.48)]. Other significant factors for both sexes were increasing education level, higher wealth status and currently/formerly being in union. CONCLUSIONS: There remains a high proportion of undiagnosed HIV-infected persons and hence there is a need for innovative strategies aimed at increasing HIV-testing, particularly for men and in lower-income and lower-educated populations. Promotion of STI services can be an important gateway for testing more men whilst ANC still remains an important option for HIV-testing among pregnant women

    Sensitivity Theorists aren't unhinged

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    Why is it difficult to implement e-health initiatives? A qualitative study

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    <b>Background</b> The use of information and communication technologies in healthcare is seen as essential for high quality and cost-effective healthcare. However, implementation of e-health initiatives has often been problematic, with many failing to demonstrate predicted benefits. This study aimed to explore and understand the experiences of implementers - the senior managers and other staff charged with implementing e-health initiatives and their assessment of factors which promote or inhibit the successful implementation, embedding, and integration of e-health initiatives.<p></p> <b>Methods</b> We used a case study methodology, using semi-structured interviews with implementers for data collection. Case studies were selected to provide a range of healthcare contexts (primary, secondary, community care), e-health initiatives, and degrees of normalization. The initiatives studied were Picture Archiving and Communication System (PACS) in secondary care, a Community Nurse Information System (CNIS) in community care, and Choose and Book (C&B) across the primary-secondary care interface. Implementers were selected to provide a range of seniority, including chief executive officers, middle managers, and staff with 'on the ground' experience. Interview data were analyzed using a framework derived from Normalization Process Theory (NPT).<p></p> <b>Results</b> Twenty-three interviews were completed across the three case studies. There were wide differences in experiences of implementation and embedding across these case studies; these differences were well explained by collective action components of NPT. New technology was most likely to 'normalize' where implementers perceived that it had a positive impact on interactions between professionals and patients and between different professional groups, and fit well with the organisational goals and skill sets of existing staff. However, where implementers perceived problems in one or more of these areas, they also perceived a lower level of normalization.<p></p> <b>Conclusions</b> Implementers had rich understandings of barriers and facilitators to successful implementation of e-health initiatives, and their views should continue to be sought in future research. NPT can be used to explain observed variations in implementation processes, and may be useful in drawing planners' attention to potential problems with a view to addressing them during implementation planning
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