651 research outputs found

    Preliminary studies on an innovative vertical axis wind turbine concept : SATVAWT

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    Vertical axis wind turbine concepts are particularly attractive for the urban environment for various reasons including adaptability to varying wind directions. On the other hand, these types of turbines suffer from various disadvantages including prohibitive costs. In this paper, we present an innovative concept of a Self Adjusting Lift Type Vertical Axis Wind Turbine (SATVAWT) being developed by the a consortium of local academia and industry. Although the project is still in its infancy some insight of the design is presented, particularly the aerodynamic and structural aspects of the blades which are being optimised for highest possible efficiency. Some results from numerical analysis tools are also presented. To provide easy start up, the turbine blades are at first retracted. Due to the accelerating motion, momentum is conserved by means of an increase in the polar moment of inertia about the axis of rotation. This causes the turbine blades to flex. In this position, advanced aerodynamic calculations using vortex methods have shown that the turbine should operate at a higher efficiency for the rated condition. Finite Element Analysis (FEA) tools have also been used to assess the structural feasibility of the turbine. The preliminary results presented here are encouraging and will form the basis for further computational and experimental analysis.Bajada New Energy Ltd., CD Power Saving Co. Ltd., Energy Investment Co. Ltd., Solar Engineering Ltd. & Solar Solutions Ltd.peer-reviewe

    Scribble modulates the MAPK/Fra1 pathway to disrupt luminal and ductal integrity and suppress tumour formation in the mammary gland

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    Polarity coordinates cell movement, differentiation, proliferation and apoptosis to build and maintain complex epithelial tissues such as the mammary gland. Loss of polarity and the deregulation of these processes are critical events in malignant progression but precisely how and at which stage polarity loss impacts on mammary development and tumourigenesis is unclear. Scrib is a core polarity regulator and tumour suppressor gene however to date our understanding of Scrib function in the mammary gland has been limited to cell culture and transplantation studies of cell lines. Utilizing a conditional mouse model of Scrib loss we report for the first time that Scrib is essential for mammary duct morphogenesis, mammary progenitor cell fate and maintenance, and we demonstrate a critical and specific role for Scribble in the control of the early steps of breast cancer progression. In particular, Scrib-deficiency significantly induced Fra1 expression and basal progenitor clonogenicity, which resulted in fully penetrant ductal hyperplasia characterized by high cell turnover, MAPK hyperactivity, frank polarity loss with mixing of apical and basolateral membrane constituents and expansion of atypical luminal cells. We also show for the first time a role for Scribble in mammalian spindle orientation with the onset of mammary hyperplasia being associated with aberrant luminal cell spindle orientation and a failure to apoptose during the final stage of duct tubulogenesis. Restoring MAPK/Fra1 to baseline levels prevented Scrib-hyperplasia, whereas persistent Scrib deficiency induced alveolar hyperplasia and increased the incidence, onset and grade of mammary tumours. These findings, based on a definitive genetic mouse model provide fundamental insights into mammary duct maturation and homeostasis and reveal that Scrib loss activates a MAPK/Fra1 pathway that alters mammary progenitor activity to drive premalignancy and accelerate tumour progression

    A Typology of Factors Influencing Seniors' Participation in Strength Training in Gyms and Fitness Centers

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    Older people are less likely to engage in strength training than their younger counterparts, despite the substantial benefits of this form of exercise for preventing and addressing age-related physical decline. In many countries, strength training programs are available for older people yet are undersubscribed. The aim of this study was to identify the factors influencing older people's participation in strength training at gyms and fitness centers to provide insights into potentially effective recruitment and retention strategies for this population. A total of 79 individuals from four stakeholder groups (seniors, fitness center instructors and managers, health practitioners, and those involved in policy) were interviewed to identify and explicate relevant factors. A detailed typology was developed that provides insights into potential strategies at five ecological system levels: intrapersonal, interpersonal, organizational, social, and policy. The typology can be used as a tool for identifying opportunities to encourage strength training participation among older people

    Sex Differences in the Association Between Depression, Anxiety, and Type 2 Diabetes Mellitus

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    Depression and anxiety have been inconsistently associated with diabetes. Sex differences in the biological and behavioral correlates of these forms of distress could partially explain these inconsistencies. We investigated sex-specific associations between depression/anxiety symptomatology and diabetes in two separate samples

    Measurement of inclusive D*+- and associated dijet cross sections in photoproduction at HERA

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    Inclusive photoproduction of D*+- mesons has been measured for photon-proton centre-of-mass energies in the range 130 < W < 280 GeV and a photon virtuality Q^2 < 1 GeV^2. The data sample used corresponds to an integrated luminosity of 37 pb^-1. Total and differential cross sections as functions of the D* transverse momentum and pseudorapidity are presented in restricted kinematical regions and the data are compared with next-to-leading order (NLO) perturbative QCD calculations using the "massive charm" and "massless charm" schemes. The measured cross sections are generally above the NLO calculations, in particular in the forward (proton) direction. The large data sample also allows the study of dijet production associated with charm. A significant resolved as well as a direct photon component contribute to the cross section. Leading order QCD Monte Carlo calculations indicate that the resolved contribution arises from a significant charm component in the photon. A massive charm NLO parton level calculation yields lower cross sections compared to the measured results in a kinematic region where the resolved photon contribution is significant.Comment: 32 pages including 6 figure

    Plastisol Foaming Process. Decomposition of the Foaming Agent, Polymer Behavior in the Corresponding Temperature Range and Resulting Foam Properties

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    The decomposition of azodicarbonamide, used as foaming agent in PVC - plasticizer (1/1) plastisols was studied by DSC. Nineteen different plasticizers, all belonging to the ester family, two being polymeric (polyadipates), were compared. The temperature of maximum decomposition rate (in anisothermal regime at 5 K min-1 scanning rate), ranges between 434 and 452 K. The heat of decomposition ranges between 8.7 and 12.5 J g -1. Some trends of variation of these parameters appear significant and are discussed in terms of solvent (matrix) and viscosity effects on the decomposition reactions. The shear modulus at 1 Hz frequency was determined at the temperature of maximum rate of foaming agent decomposition, and differs significantly from a sample to another. The foam density was determined at ambient temperature and the volume fraction of bubbles was used as criterion to judge the efficiency of the foaming process. The results reveal the existence of an optimal shear modulus of the order of 2 kPa that corresponds roughly to plasticizer molar masses of the order of 450 Β± 50 g mol-1. Heavier plasticizers, especially polymeric ones are too difficult to deform. Lighter plasticizers such as diethyl phthalate (DEP) deform too easily and presumably facilitate bubble collapse

    Observation of Scaling Violations in Scaled Momentum Distributions at HERA

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    Charged particle production has been measured in deep inelastic scattering (DIS) events over a large range of xx and Q2Q^2 using the ZEUS detector. The evolution of the scaled momentum, xpx_p, with Q2,Q^2, in the range 10 to 1280 GeV2GeV^2, has been investigated in the current fragmentation region of the Breit frame. The results show clear evidence, in a single experiment, for scaling violations in scaled momenta as a function of Q2Q^2.Comment: 21 pages including 4 figures, to be published in Physics Letters B. Two references adde

    Measurement of Jet Shapes in Photoproduction at HERA

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    The shape of jets produced in quasi-real photon-proton collisions at centre-of-mass energies in the range 134βˆ’277134-277 GeV has been measured using the hadronic energy flow. The measurement was done with the ZEUS detector at HERA. Jets are identified using a cone algorithm in the Ξ·βˆ’Ο•\eta - \phi plane with a cone radius of one unit. Measured jet shapes both in inclusive jet and dijet production with transverse energies ETjet>14E^{jet}_T>14 GeV are presented. The jet shape broadens as the jet pseudorapidity (Ξ·jet\eta^{jet}) increases and narrows as ETjetE^{jet}_T increases. In dijet photoproduction, the jet shapes have been measured separately for samples dominated by resolved and by direct processes. Leading-logarithm parton-shower Monte Carlo calculations of resolved and direct processes describe well the measured jet shapes except for the inclusive production of jets with high Ξ·jet\eta^{jet} and low ETjetE^{jet}_T. The observed broadening of the jet shape as Ξ·jet\eta^{jet} increases is consistent with the predicted increase in the fraction of final state gluon jets.Comment: 29 pages including 9 figure

    Jet energy measurement with the ATLAS detector in proton-proton collisions at root s=7 TeV

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    The jet energy scale and its systematic uncertainty are determined for jets measured with the ATLAS detector at the LHC in proton-proton collision data at a centre-of-mass energy of √s = 7TeV corresponding to an integrated luminosity of 38 pb-1. Jets are reconstructed with the anti-kt algorithm with distance parameters R=0. 4 or R=0. 6. Jet energy and angle corrections are determined from Monte Carlo simulations to calibrate jets with transverse momenta pTβ‰₯20 GeV and pseudorapidities {pipe}Ξ·{pipe}<4. 5. The jet energy systematic uncertainty is estimated using the single isolated hadron response measured in situ and in test-beams, exploiting the transverse momentum balance between central and forward jets in events with dijet topologies and studying systematic variations in Monte Carlo simulations. The jet energy uncertainty is less than 2. 5 % in the central calorimeter region ({pipe}Ξ·{pipe}<0. 8) for jets with 60≀pT<800 GeV, and is maximally 14 % for pT<30 GeV in the most forward region 3. 2≀{pipe}Ξ·{pipe}<4. 5. The jet energy is validated for jet transverse momenta up to 1 TeV to the level of a few percent using several in situ techniques by comparing a well-known reference such as the recoiling photon pT, the sum of the transverse momenta of tracks associated to the jet, or a system of low-pT jets recoiling against a high-pT jet. More sophisticated jet calibration schemes are presented based on calorimeter cell energy density weighting or hadronic properties of jets, aiming for an improved jet energy resolution and a reduced flavour dependence of the jet response. The systematic uncertainty of the jet energy determined from a combination of in situ techniques is consistent with the one derived from single hadron response measurements over a wide kinematic range. The nominal corrections and uncertainties are derived for isolated jets in an inclusive sample of high-pT jets. Special cases such as event topologies with close-by jets, or selections of samples with an enhanced content of jets originating from light quarks, heavy quarks or gluons are also discussed and the corresponding uncertainties are determined. Β© 2013 CERN for the benefit of the ATLAS collaboration
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