63 research outputs found

    Pengujian Karakteristik Unjuk Kerja Turbin Mikrohidro Di Desa Ciasmara

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    Experimental study of performance characteristic of micro-hydro water turbine hasbeen done in Kabitpaten Bogor. In this study performance is defined as a turbine efficiency which isrepresented by ratio between mechanical energy provided by turbine and an available potential energyofwater at a various conditions offlow. The study was limited only at several variation ofwater flowrate because the turbine installation is only equipped by conventional control system. Water level inthe basin was measured by level water meter with the precision is around 10%, while water flow ratewas measured by bridge flow meter. Mechanical energy is calculatedfrom measurement ofrotationalmoment and rotation of shaft. The moment was measured by calibrated hydraulic dynamometer andthe shaft rotation was measured by stroboscope. Based on the test results, at the full capacity (0.305mlIs flow rate and 3.17 mhead) the turbine showed agood performance with the efficiency is around59%

    A ferromagnet with a glass transition

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    We introduce a finite-connectivity ferromagnetic model with a three-spin interaction which has a crystalline (ferromagnetic) phase as well as a glass phase. The model is not frustrated, it has a ferromagnetic equilibrium phase at low temperature which is not reached dynamically in a quench from the high-temperature phase. Instead it shows a glass transition which can be studied in detail by a one step replica-symmetry broken calculation. This spin model exhibits the main properties of the structural glass transition at a solvable mean-field level.Comment: 7 pages, 2 figures, uses epl.cls (included

    Record RF performance of standard 90 nm CMOS technology

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    We have optimized 3 key RF devices realized in standard logic 90 nm CMOS technology and report a record performance in terms of n-MOS maximum oscillation frequency f/sub max/ (280 GHz), varactor tuning range and varactor and inductor quality factor

    THREE-DIMENSIONAL ANALYSIS OF TURBINE ROTOR FLOW INCLUDING TIP CLEARANCE

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    A 3D Navier-Stokes investigation of a high pressure turbine rotor blade including tip clearance effects is presented. The 3D Navier-Stokes code developed at ONERA solves the three-dimensional unsteady set of mass-averaged Navier-Stokes equations by the finite volume technique. A one step Lax-Wendroff type scheme is used in a rotating frame of reference. An implicit residual smoothing technique has been implemented, which accelerates the convergence towards the steady state. A mixing length model adapted to 3D configurations is used. The turbine rotor flow is calculated at transonic operating conditions. The tip clearance effect is taken into account. The gap region is discretized using more than 55,000 points within a multi-domain approach. The solution accounts for the relative motion of the blade and casing surfaces. The total mesh is composed of five sub-domains and counts 710,000 discretization points

    Syndromes of self-reported psychopathology for ages 18-59 in 29 societies

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    This study tested the multi-society generalizability of an eight-syndrome assessment model derived from factor analyses of American adults' self-ratings of 120 behavioral, emotional, and social problems. The Adult Self-Report (ASR; Achenbach and Rescorla 2003) was completed by 17,152 18-59-year-olds in 29 societies. Confirmatory factor analyses tested the fit of self-ratings in each sample to the eight-syndrome model. The primary model fit index (Root Mean Square Error of Approximation) showed good model fit for all samples, while secondary indices showed acceptable to good fit. Only 5 (0.06%) of the 8,598 estimated parameters were outside the admissible parameter space. Confidence intervals indicated that sampling fluctuations could account for the deviant parameters. Results thus supported the tested model in societies differing widely in social, political, and economic systems, languages, ethnicities, religions, and geographical regions. Although other items, societies, and analytic methods might yield different results, the findings indicate that adults in very diverse societies were willing and able to rate themselves on the same standardized set of 120 problem items. Moreover, their self-ratings fit an eight-syndrome model previously derived from self-ratings by American adults. The support for the statistically derived syndrome model is consistent with previous findings for parent, teacher, and self-ratings of 11/2-18-year-olds in many societies. The ASR and its parallel collateral-report instrument, the Adult Behavior Checklist (ABCL), may offer mental health professionals practical tools for the multi-informant assessment of clinical constructs of adult psychopathology that appear to be meaningful across diverse societies

    Personality profiles of cultures: aggregate personality traits

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    Personality profiles of cultures can be operationalized as the mean trait levels of culture members. College students from 51 cultures rated an individual from their country whom they knew well (N = 12, 156). Aggregate scores on Revised NEO Personality Inventory scales generalized across age and gender groups, approximated the individual-level Five-Factor Model, and correlated with aggregate self-report personality scores and other culture-level variables. Results were not attributable to national differences in economic development or to acquiescence. Geographical differences in scale variances and mean levels were replicated, with Europeans and Americans generally scoring higher in Extraversion than Asians and Africans. Findings support the rough scalar equivalence of NEO-PI-R factors and facets across cultures, and suggest that aggregate personality profiles provide insight into cultural differences

    Characterisation of uranium vacancies in hyper stoichiometric uranium dioxide

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    An experimental method, based on measurements of the expansion of a single crystal as a function of the p(O-2) was used to determine the concentration of uranium vacancies in hyperstoichiometric Uranium dioxide. The results are consistent with the concentration of electrical carriers measured in the same conditions, they are also in qualitative agreement with a theoretical modelling proposed in the literature. However, an improved interpretation would require to take into account the clusters of oxygen interstitials and vacancies
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