2,934 research outputs found

    Aqueous to organic phase transfer of Au<SUB>25</SUB> clusters

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    Aqueous to organic phase transfer of water soluble sub-nanocluster, Au25SG18 (-SG, glutathione thiolate) is demonstrated using the phase transfer reagent, tetraoctylammonium bromide. The phase transfer occurred by the electrostatic attraction between the hydrophilic carboxylate anion of the glutathione ligand on the cluster surface in the aqueous phase and the hydrophobic tetraoctylammonium cation in the toluene phase. Detailed spectroscopic characterization of the phase transferred cluster using optical absorption, photoluminescence and X-ray photoelectron spectroscopy showed that the cluster retains its integrity during the phase transfer. The interaction of the cluster with the phase transfer reagent can be studied with infrared spectroscopy. The phase transferred cluster can be dried and redissolved in an organic medium, just as the original cluster. This is the first report of the phase transfer of a sub-nanocluster, keeping the cluster core intact. The effect of dilution and pH on phase transfer of this cluster is studied in detail. This method promises several possibilities to explore the properties, reactivity and applications of sub-nanoclusters both in the aqueous and organic phases

    Backyard Chicken Farming: For Income, Health and Happiness

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    Backyard Chicken Farming: For Income, Health and Happines

    Cardiac Valvular Inflammatory Pseudotumor

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    Inflammatory pseudotumors are quasineoplastic lesions that occur in the lungs as well as other extrapulmonary sites. The heart is an uncommon site of origin. We report a valvular pseudotumor that produced chronic mitral and aortic regurgitation in an elderly woman

    Radiative Phase Transitions and Casmir Effect Instabilities

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    Molecular quantum electrodynamics leads to photon frequency shifts and thus to changes in condensed matter free energies often called the Casimir effect. Strong quantum electrodynamic coupling between radiation and molecular motions can lead to an instability beyond which one or more photon oscillators undergo a displacement phase transition. The phase boundary of the transition can be located by a Casimir free energy instability.Comment: ReVTeX4 format 1 *.eps figur

    A Qualitative Analysis of Indoor Air Quality Pollutants inside a Private Car Cabin Using Response Surface Methodology

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    Indoor air quality (IAQ) plays a significant role in our daily life. IAQ is not only important in interior buildings but is also essential to the low volume space of automobile compartments. This study investigates the three critical IAQ pollutants of CO2, PM2.5, and PM10 in an air-conditioned private car cabin. Three qualitative input factors of human load, route, and air conditioning (ON and OFF) were considered to evaluate the effect of in-cabin car pollutants. Analysis of variance (ANOVA) was applied to determine the effect of the input parameters that affect IAQ in the car cabin. A mathematical modelling of response factors (pollutants) was determined using response surface methodology (RSM) in connection with the Taguchi orthogonal test design. It was found that indoor car cabin CO2, PM2.5, and PM10 concentrations were 3.32, 1.35, and 1.33 times higher than the on-road concentrations, respectively. The air-conditioning input factor has more effects for in-cabin pollutants compared with the other two input factors of human load and route. The R2 values obtained were greater than 95% for all the response factors. According to the American Society of Heating, Refrigeration and Air Conditioning Engineers (ASHRAE) standard limit, the air supply flow rate of 7.64 l/s per human (maximum 4 human load) was not enough to keep CO2 concentrations below 1000 ppm in the currently tested car cabin

    Glass transition in biomolecules and the liquid-liquid critical point of water

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    Using molecular dynamics simulations, we investigate the relation between the dynamic transitions of biomolecules (lysozyme and DNA) and the dynamic and thermodynamic properties of hydration water. We find that the dynamic transition of the macromolecules, sometimes called a ``protein glass transition'', occurs at the temperature of dynamic crossover in the diffusivity of hydration water, and also coincides with the maxima of the isobaric specific heat CPC_P and the temperature derivative of the orientational order parameter. We relate these findings to the hypothesis of a liquid-liquid critical point in water. Our simulations are consistent with the possibility that the protein glass transition results from crossing the Widom line, which is defined as the locus of correlation length maxima emanating from the hypothesized second critical point of water.Comment: 10 Pages, 12 figure

    Will “opt out” implementation save more lives; view of the South Asians’ in the UK

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    Organ transplantation is the gold standard treatment of choice for many patients with organ failure and has undoubtedly improved both the quality and longevity of life for the majority of patients. The success of human organ transplantation relies on the willingness of the public to donate their organs, either during their lifetime or after death. In the United Kingdom (UK), transplantation is limited by a shortage of donated organs, especially in the South Asian community. This leads to a disproportionate number of Asians waiting for transplants longer than the average waiting time, as often, most suitable matches are found between people of the same ethnic group. This disparity costs lives, and many who are waiting count down their days on the list and lead an agonizing life due to the scarcity of matching organ donors. This article is derived from a two phased study that sought to explore possible methods to increase the number of registered organ donors and cadaver organ retrieval in the South Asian community in the North West of England. A total of 907 participants completed the questionnaire and 10 semi structured interviews with individuals who declined to join the organ donor register were undertaken to understand the in-depth details of their negative attitude towards organ donation. This paper reflects on one of the focus areas of the study - the views of South Asians on the implementation of an opt-out system in the UK and to understand if the community will challenge or support such a donor recruitment method. This study was funded by the British Renal Society and supported by the Central Manchester Foundation Trust, University of Salford and National Health Service Blood and Transplant (NHSBT). Keywords: South Asian, Knowledge, Survey, Organ donation, Opt out, Opt in, Religio

    DEVELOPMENT OF A DEVICE TO MEASURE THE BLADE TIP CLEARANCE OF AN AXIAL COMPRESSOR

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    Axial compressors, used in gas turbines, jet engines and also small scale power plants, are rotating, airfoil based compressors in which the working fluid flows parallel to the axis of rotation. There has been continuous struggle to maximize the efficiency of these compressors. One of the many ways to achieve the same is to minimize the tip clearance i.e. to reduce the distance between the blade tip and the housing. Experiments need to be conducted to measure the changes in the tip clearance while the  compressor is operating. Conventional devices to measure this tip clearance have proven to be costly if a small scale application is under consideration. Our aim in this project is to develop a device which will measure the blade tip clearance of an axial flow compressor economically. The literature review, development of the device, its working and results will be discussed in this paper

    Effect of water-wall interaction potential on the properties of nanoconfined water

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    Much of the understanding of bulk liquids has progressed through study of the limiting case in which molecules interact via purely repulsive forces, such as a hard-core potential. In the same spirit, we report progress on the understanding of confined water by examining the behavior of water-like molecules interacting with planar walls via purely repulsive forces and compare our results with those obtained for Lennard-Jones (LJ) interactions between the molecules and the walls. Specifically, we perform molecular dynamics simulations of 512 water-like molecules which are confined between two smooth planar walls that are separated by 1.1 nm. At this separation, there are either two or three molecular layers of water, depending on density. We study two different forms of repulsive confinements, when the interaction potential between water-wall is (i) 1/r91/r^9 and (ii) WCA-like repulsive potential. We find that the thermodynamic, dynamic and structural properties of the liquid in purely repulsive confinements qualitatively match those for a system with a pure LJ attraction to the wall. In previous studies that include attractions, freezing into monolayer or trilayer ice was seen for this wall separation. Using the same separation as these previous studies, we find that the crystal state is not stable with 1/r91/r^9 repulsive walls but is stable with WCA-like repulsive confinement. However, by carefully adjusting the separation of the plates with 1/r91/r^9 repulsive interactions so that the effective space available to the molecules is the same as that for LJ confinement, we find that the same crystal phases are stable. This result emphasizes the importance of comparing systems only using the same effective confinement, which may differ from the geometric separation of the confining surfaces.Comment: 20 pages, 10 figure
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