12,787 research outputs found

    Hydrophobic Polymers from Food Waste: Resources and Synthesis

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    The food waste generated annually is approximately 1.3 Pg. It contains chemical feedstock that could be diverted to materials production as the mineral oil price rises, incurring no conflict over land use and providing new wealth-creating opportunities for food-producing countries. It potentially realigns the industrial and agricultural sectors of national economies. Food waste production scales with population as does demand for materials. This review builds upon previous landmark papers in Polymer Reviews that address biomass in polymer production. It surveys the current global food-waste resource and demonstrates how it could be used in the generation of hydrophobic polymers

    Evaluation of Supermarket Energy Use and Emissions with Various Technology Options

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    In this paper, an operational supermarket in the UK has been selected to be modelled by the previously developed supermarket energy simulation software ā€˜SuperSIMā€™. Detailed information of the supermarket and model development procedures are explained. The model was previously validated through comparisons with site measurements of space air temperature and humidity and energy consumptions. It is therefore used to simulate, quantify and evaluate supermarket energy performance at various technology options in terms of heat recovery from refrigerant discharge, high efficiency condensers and evaporators and store locations etc

    National Evaluation of the Capacity Building Programme in English Local Government: Evaluation of the National Programmes: Annex 2: Evaluation of the National Programmes

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    The report is one of a series of outputs from the national evaluation of the CBP, being undertaken by a team of researchers at the Policy Research Institute (PRI) at Leeds Metropolitan University and the Cities Research Unit at the University of West of England. The Capacity Building Programme for local government was launched in 2003 as a joint Department for Communities and Local Government (DCLG) / Local Government Association (LGA) initiative to support capacity building and improvement activities within local authorities in England. The evaluation of the Capacity Building Programme has been underway since late 2004. A scoping phase was conducted until May 2005, including a short evaluation of the Pilot Programmes. The main phase of the evaluation commenced in September 2005 and encompassed four main phases (see Section 1.3: p10)

    Inter-individual variability in current direction for common tDCS montages

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    The direction of applied electric current relative to the cortical surface is a key determinant of transcranial direct current stimulation (tDCS) effects. Inter-individual differences in anatomy affect the consistency of current direction at a cortical target, likely leading to inter-individual variability in current direction. However, the degree of this variability remains undetermined. Using current flow modelling (CFM), we quantified the inter-individual variability in tDCS current direction at a cortical target (left primary motor cortex, M1). Three montages targeting M1 using circular electrodes were compared: PA-tDCS directed current perpendicular to the central sulcus in a posterior-anterior direction relative to M1, ML-tDCS directed current parallel to the central sulcus in a medio-lateral direction, and conventional-tDCS applied electrodes over M1 and the contralateral forehead. In 50 healthy brain scans from the Human Connectome Project, we extracted current direction and intensity from the gray matter surface in the sulcal bank (M1BANK) and gyral crown (M1CROWN), and neighbouring primary somatosensory cortex (S1BANK and S1CROWN). Results confirmed substantial inter-individual variability in current direction (50%-150%) across all montages. Radial inward current produced by PA-tDCS was predominantly located in M1BANK, whereas for conventional-tDCS it was clustered in M1CROWN. The predominantly radial inward current in functionally distinct subregions of M1 raises the testable hypothesis that PA-tDCS and conventional-tDCS modulate cortical excitability through different mechanisms. We show that electrode locations can be used to closely approximate current direction in M1 and precentral gyrus, providing a landmark-based method for tDCS application to address the hypothesis without the need for MRI. By contrast, ML-tDCS current was more tangentially oriented, which is associated with little somatic polarization. Substantial inter-individual variability in current direction likely contributes to variable neuromodulation effects reported for these protocols, emphasising the need for individualised electrode montages, including the control of current direction

    On-chip production of nanometer sized 'Ultra fine' bubble populations

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    Microbubble (MB) contrast agents have been used for many years as image enhancers for medical Ultrasound (US). Ultra-Fine bubble (UFB) populations of bubbles <1 Āµm in diameter are a relatively new technology that has found use as highly effective ā€˜ecoā€™ cleaning agents. High-resolution US imaging is another potentially exciting area for UFB. This paper reports the on-chip production of UFB populations with a diameter of ~ 500 ā€“ 700 nm at a concentration of 10Ā¹ā° bub / mL. These UFB showed US scattering at higher frequency fields and enhanced contrast when imaging in in vivo mouse models

    Impact of Taste on Food Choices in Adolescenceā€”Systematic Review and Meta-Analysis

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    Studies of adults report that perceived taste affects food choices and intake, which in turn may have an impact on health. However, corresponding evidence on adolescents is limited.ā€Æ Our aim was to summarize current evidence of the impact of taste perception on food choice preferences or dietary intakes among adolescents (mean age 10ā€“19.9 years). Systematic searches identified 13 papers, 12 cross-sectional and one cohort study published between 1 January 2000 to 20 February 2020 assessing the impact of taste (using phenotypic and/or genotypic markers) on food choices in adolescents without any disease conditions. Qualitative assessment in the current review indicated that individuals sensitive to bitter tastes often have a lower preference of bitter-tasting food and higher preference for sweet-tasting food. A meta-analysis of three studies on bitter-taste sensitivity revealedā€Æno difference in preference for bitter-tasting vegetables between bitter tasters and non-tasters (standardized mean difference (SMD) = 0.04; 95% CI: āˆ’0.18, 0.26; p = 0.72). Overall, a limited number of studies were available for review. As a result, we report no clear relationship between taste perception and food choices or intake in adolescents. More studies are needed to evaluate the link between adolescentsā€™ taste perceptions and dietary intake

    Patient deprivation and perceived scan burden negatively impact on the quality of WB-MRI

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    Aim: To evaluate the association between cancer staging whole body WB-MRI (WB-MRI) image quality and patient demographics, distress and perceived scan burden Materials and Methods: A sample of patients prospectively recruited to multicentre trials comparing WB-MRI with standard scans for staging lung and colorectal cancer, were invited to complete two questionnaires. The baseline questionnaire, administered at recruitment, collated data on demographics, distress and co-morbidity; the follow-up questionnaire, completed after staging investigations, measured perceived WB-MRI scan burden (scored 1 low to 7 high). WB-MRI anatomical coverage and technical quality was graded by a radiographic technician and grading combined to categorise the scan as ā€˜optimalā€™, ā€˜sub-optimalā€™ or ā€˜degradedā€™. A radiologist categorised 30 scans to test inter-observer agreement. Data were analysed using Chi Square, Fisher Exact, t-tests and multinomial regression. Results: 114 patients were included in the study (53 lung, 61 colorectal; average age 65.3, SD=11.8; 66 men, (57.9%)). Overall, 45.6% (n=52), scans were classified as ā€˜optimalā€™ quality, 39.5% (n=45) ā€˜sub-optimalā€™ and 14.9% (n=17) as ā€˜degradedā€™. In adjusted analyses greater deprivation level and higher patient-reported scan burden were both associated with a higher likelihood of having a sub-optimal vs. an optimal scan (OR: 4.465, CI: 1.454 to 13.709, p=0.009; OR: 1.987, CI: 1.153 to 3.425, p=0.013 respectively). None of the variables predicted the likelihood of having a degraded scan. Conclusions: Deprivation as well as patientsā€™ perceived experience of the WB-MRI, is related to image quality. Tailored protocols and individualised patient management before and during WB-MRI may improve scan quality

    Holographic DC conductivities from the open string metric

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    We study the DC conductivities of various holographic models using the open string metric (OSM), which is an effective metric geometrizing density and electromagnetic field effect. We propose a new way to compute the nonlinear conductivity using OSM. As far as the final conductivity formula is concerned, it is equivalent to the Karch-O'Bannon's real-action method. However, it yields a geometrical insight and technical simplifications. Especially, a real-action condition is interpreted as a regular geometry condition of OSM. As applications of the OSM method, we study several holographic models on the quantum Hall effect and strange metal. By comparing a Lifshitz background and the Light-Cone AdS, we show how an extra parameter can change the temperature scaling behavior of conductivity. Finally we discuss how OSM can be used to study other transport coefficients, such as diffusion constant, and effective temperature induced by the effective world volume horizon.Comment: 33 page

    Combined flow-focus and self-assembly routes for the formation of lipid stabilized oil-shelled microbubbles

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    Lipid and polymer stabilized microbubbles are used in medicine as contrast agents for ultrasound imaging and are being developed for the delivery of water soluble drugs to diseased areas of the body. However, many new therapeutics exhibit poor water solubility or stability, which has led to the requirement for the development of effective hydrophobic drug delivery systems. This study presents a new method to produce microbubbles coated with an oil layer capable of encapsulating hydrophobic drugs and suitable for targeted, triggered drug release. This new method utilizes highly controllable flow-focusing microfluidics with lipid oil nanodroplets self-assembling and spreading at gasā€“aqueous interfaces. Oil layer inside microbubbles were produced with diameters of 2.4Ā±0.3ā€‰Ī¼m (s.d., 1.6ā€‰Ī¼m) and at concentrations up to 106 bubbles per milliliter. The mechanism of oil layer inside microbubble assembly and stability were characterized using methods including contact angle measurements, quartz crystal microbalance with dissipation monitoring and fluorescence resonance energy transfer imaging

    Collective Excitations of Holographic Quantum Liquids in a Magnetic Field

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    We use holography to study N=4 supersymmetric SU(Nc) Yang-Mills theory in the large-Nc and large-coupling limits coupled to a number Nf << Nc of (n+1)-dimensional massless supersymmetric hypermultiplets in the Nc representation of SU(Nc), with n=2,3. We introduce a temperature T, a baryon number chemical potential mu, and a baryon number magnetic field B, and work in a regime with mu >> T,\sqrt{B}. We study the collective excitations of these holographic quantum liquids by computing the poles in the retarded Green's function of the baryon number charge density operator and the associated peaks in the spectral function. We focus on the evolution of the collective excitations as we increase the frequency relative to T, i.e. the hydrodynamic/collisionless crossover. We find that for all B, at low frequencies the tallest peak in the spectral function is associated with hydrodynamic charge diffusion. At high frequencies the tallest peak is associated with a sound mode similar to the zero sound mode in the collisionless regime of a Landau Fermi liquid. The sound mode has a gap proportional to B, and as a result for intermediate frequencies and for B sufficiently large compared to T the spectral function is strongly suppressed. We find that the hydrodynamic/collisionless crossover occurs at a frequency that is approximately B-independent.Comment: 45 pages, 8 png and 47 pdf images in 22 figure
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