636 research outputs found

    FTIR and XRD studies on some archaeological artifacts from Bohn, India

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              Spectroscopic studies have been performed on archaeological pottery samples from Bhon in Maharashtra. The clay mineral type and its structural deformation due to firing have been studied from their Fourier Transform Infrared (FTIR) spectra. The maximum firing temperature attained during baking, firing conditions (open/reduced atmosphere) and iron mineral phase changes are well established. X-ray diffraction (XRD) studies on archaeological artifacts pave the way to identify the minerals

    Submerged membrane filtration adsorption hybrid system for the removal of organic micropollutants from a water reclamation plant reverse osmosis concentrate

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    © 2016 Elsevier B.V. Reverse osmosis (RO) is a widespread water treatment process utilised in water reuse applications. However, the improper discharge of RO concentrate (ROC) containing organic micropollutants such as pharmaceuticals into the environment may cause potential health risks to non-target species and particularly those in aquatic environments. A study was conducted using a submerged membrane-filtration/granular activated carbon (GAC) adsorption hybrid system to remove organic micropollutants from a water treatment plant ROC by initially adding 10 g GAC /L of membrane reactor volume with 10% daily GAC replacement. The percentage of dissolved organic carbon removal varied from 60% to 80% over an operation lasting 10 days. Removal of organic micropollutants was almost complete for virtually all compounds. Of the 19 micropollutants tested, only two remained (the less hydrophobic DEET 27 ng/L and the hydrophilic sulfamethoxazole 35 ng/L) below 80% removal on day 1, while five of the most hydrophobic micropollutants were detectable in very small concentrations ( 89%–> 99% being removed. High percentages of micropollutants were removed probably because of their high hydrophobicity or they had positive or neutral charges and therefore they were electrostatically adsorbed to the negatively charged GAC

    Simultaneous removal of natural organic matter and micro-organic pollutants from reverse osmosis concentrate using granular activated carbon

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    © 2019 Elsevier Ltd Although reverse osmosis produces high quality reusable water from wastewater the rejected concentrate (ROC) poses potentially serious health hazards to non-target species. This is especially the case when it is disposed into aquatic environments due to the presence of high concentrations of dissolved natural organics, micro-organic pollutants (MOPs) and other pollutants. In batch and column studies we found that granular activated carbon (GAC) was very effective in simultaneously removing dissolved organic carbon (DOC) and 18 MOPs from ROC. The amounts of all DOC fractions adsorbed (0.01–3 mg/g) were much higher than those of the MOPs (0.01–2.5 μg/g) mainly because ROC contained larger concentrations of DOC fractions than MOPs. However, the partition coefficient which is a measure of the adsorbability was higher for most of the MOPs (0.21–21.6 L/g) than for the DOC fractions (0.01–0.45 L/g). The amount of DOC fraction adsorbed was in the order: humics > low molecular weights > building blocks > biopolymers (following mostly their concentrations in ROC). The partition coefficient was in the order: low molecular weigth nuetrals > humics > building blocks > biopolymers. The MOPs were classified into four groups based on their hydrophobicity (log Kow) and charge. The four positively charged MOPs with high hydrophobicity had the highest amounts adsorbed and partition coefficient, with 95–100% removal in the GAC column. The MOPs that are negatively charged, regardless of their hydrophobicity, had the lowest amounts adsorbed and partition coefficient with 73–94% removal

    Relational Solidarity and Conflicting Ethics in Dementia Care in Urban India.

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    OBJECTIVES: Using the concept of relational solidarity, we examine how autonomy, equality, dignity, and personhood are practiced in the care of people living with dementia at home in urban India. METHODS: Video interviews with 19 family carers and 25 health providers conducted in English, Hindi, and Kannada in Bengaluru between March and July 2022. Data were translated into English and thematically analyzed. RESULTS: Family carers and providers unanimously agreed that people with dementia should be respected and cared for. Concurrently, they perceived people with dementia as being "like a kid" and used the analogy of a parent-child relationship to understand their care responsibilities. This analogy informed how ethical principles such as personhood and equality were reframed in the relationships between family carers and people with dementia, as well as how carers and providers maintained the safety but undermined the autonomy of people with dementia through restricting their movements inside and outside the home. DISCUSSION: There can be relational solidarity in dementia care at home in urban India but also contradictions in the interpretations and applications of the ethical principles of autonomy, equality, dignity, and personhood. As such, a more organic, grassroots model of ethical practice is needed to frame care and provide material support to families in India

    Social media for supply chain risk management

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    Agency for Science, Technology and Research (A*STAR

    Experimental and numerical analyses of magnesium alloy hot workability

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    AbstractDue to their hexagonal crystal structure, magnesium alloys have relatively low workability at room temperature. In this study, the hot workability behavior of cast-extruded AZ31B magnesium alloy is studied through hot compression testing, numerical modeling and microstructural analyses. Hot deformation tests are performed at temperatures of 250 °C to 400 °C under strain rates of 0.01 to 1.0 s−1. Transmission electron microscopy is used to reveal the presence of dynamic recrystallization (DRX), dynamic recovery (DRY), cracks and shear bands. To predict plastic instabilities during hot compression tests of AZ31B magnesium alloy, the authors use Johnson–Cook damage model in a 3D finite element simulation. The optimal hot workability of magnesium alloy is found at a temperature (T) of 400 °C and strain rate (ε˙) of 0.01 s−1. Stability is found at a lower strain rate, and instability is found at a higher strain rate
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