Rapid prototyping of micro-optics for brightness restoration of diode lasers

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Dynamics and asymmetric rent adjustments in the office market in Warsaw

Dynamics of rent, vacancy, supply and demand on the office market of emerging commercial real estate markets have long been under-researched. The paper fills the gap in economic literature by investigating the growing office market in Warsaw. In particular, we evaluate whether the influence of demand and supply shocks differ depending on the current market conditions. Using Error Correction Model approach, we investigated the rent adjustments on the office market in Warsaw, which is the major property market in Central and Eastern Europe. We replaced variables of the basic model with asymmetric variables to check for asymmetric adjustments in the office market. The study period covers data from 2005:1Q to 2016:1Q. The empirical results suggest that demand shock had a stronger impact on rent when the market vacancy rate was below the average for the period considered. Additionally, the demand shock had a stronger impact on rent when the rent was above the equilibrium level

Heat Transfer Process Within The R744 Two-phase Ejector: Numerical And Experimental Study

The proposed three dimensional CFD model to simulate the influence of the heat transfer on the R744 two-phase ejector performance is presented. The numerical model was developed based on the homogeneous real fluid flow assumption with the enthalpy-based formulation of the energy equation. The R744 two-phase ejector was designed to evaluate the temperature profile within the ejector walls. The prototype R744 ejector for experimental investigation was manufactured by Institute of Thermal Technology and ATM in Poland. The performance measurements were carried out at a R744 test facility at SINTEF/NTNU in Norway. The foregoing ejector was equipped with the thirteen thermocouples located inside the ejector to measure the wall temperature in different ejector section i.e. the motive nozzle, the suction nozzle, the mixing section and the diffuser. The experimental test campaign at different operating conditions typical for refrigeration application was carried out and the uncertainty of the measurement was defined. Moreover, the experimental data are applied to validate the CFD results at defined operating conditions. The numerical results were set to evaluate the influence of the wall temperature on the two-phase flow parameters. In addition, the heat transfer coefficient of the two-phase flow within the ejector was estimated. The analysis of the heat transfer process within the R744 two-phase ejector let to investigate the influence of the ambient conditions and the different temperature levels of the motive and suction streams on the ejector performance

Thermal analysis of 8.5 MVA disk-type power transformer cooled by biodegradable ester oil working in ONAN mode by using advanced EMAG–CFD–CFD coupling

Power transformers are the first devices used to transfer the electrical energy produced in power plants to the grid to supply the industrial and individual receivers with electricity. The heat generation in windings and core, being an effect of the power losses, is usually dissipated in large units by using mineral oils, which are harmful to the environment. Nowadays, the industry and global society seek environmentally-friendly alternatives. One of the most promising substitute for their high biodegradability, safety in operation, and favourable thermo-physical properties are natural ester oils. For this reason, a numerical study of 8.5 MVA disk-type power transformer cooled using conventional mineral oil and a commercially used rapeseed ester oil is presented in this paper. Moreover, due to different thermal behaviour of the considered oils, the comparison was made for the unit working in different seasons of hot and moderate climate zones (Argentina and Poland). In the numerical approach, electromagnetic (EMAG) and computational fluid dynamics (CFD) models were used for a detailed study of the selected device. In particular, a novel and very efficient EMAG–CFD–CFD coupling procedure was developed to assess the cooling of the large power transformer. Such a coupled computational procedure allowed for the detailed investigation of the power loss, oil flow characteristics, and temperatures with a satisfying computational effort. The results showed that the average windings temperatures are higher by 2–9 K when the ester oil is used, dependent on the ambient conditions. The hotspot temperature in the low voltage windings increased by up to 9 K and up to 18 K in the high voltage windings using ester oil. According to the results, the oil duct construction requires modification in the high voltage region for transformers cooled using mineral oil in cold climate conditions.Fil: Stebel, Michal. Silesian University Of Technology; PoloniaFil: Kubiczek, Krzysztof. Silesian University Of Technology; PoloniaFil: Rios Rodriguez, Gustavo Adolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Centro de Investigaciones en Métodos Computacionales. Universidad Nacional del Litoral. Centro de Investigaciones en Métodos Computacionales; ArgentinaFil: Palacz, Michal. Silesian University Of Technology; PoloniaFil: Garelli, Luciano. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Centro de Investigaciones en Métodos Computacionales. Universidad Nacional del Litoral. Centro de Investigaciones en Métodos Computacionales; ArgentinaFil: Melka, Bartlomiej. Silesian University Of Technology; PoloniaFil: Haida, Michal. Silesian University Of Technology; PoloniaFil: Bodys, Jakub. Silesian University Of Technology; PoloniaFil: Nowak, Andrzej J.. Silesian University Of Technology; PoloniaFil: Lasek, Pawel. Silesian University Of Technology; PoloniaFil: Stepien, Mariusz. Silesian University Of Technology; PoloniaFil: Pessolani, Francisco. Tadeo Czerweny S.a.; ArgentinaFil: Amadei, Mauro. Tadeo Czerweny S.a.; ArgentinaFil: Granata, Daniel. Tadeo Czerweny S.a.; ArgentinaFil: Storti, Mario Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Centro de Investigaciones en Métodos Computacionales. Universidad Nacional del Litoral. Centro de Investigaciones en Métodos Computacionales; ArgentinaFil: Smolka, Jacek. Silesian University Of Technology; Poloni

Development of the natural working fluid‐based refrigeration system for domestic scale freeze‐dryer

In this work, the analysis of the refrigeration system designed for the FrostX 10 freeze‐dryer is presented. The main goal of this study was to experimentally investigate the reference R452a freeze‐dryer and prepare recommendations for a machine based on the R290 refrigeration unit. In order to guarantee the temperature requirements and efficient operation of that unit, the analysis of suitable natural refrigerants was performed. Consequently, propane (R290) was selected. In addition, a number of modifications were introduced for the prototype system. System analysis showed that the replacement of the refrigerant in the existing system improves the system energy efficiency by approximately 18%. During the experimental campaign of the basic refrigeration unit, an unstable operation of the evaporator was found. The concept of a new cooling system for a prototype device was presented. The configuration and type of heat exchanger to maximise the performance of the ice trap of the freeze‐dryer were proposed.Development of the natural working fluid‐based refrigeration system for domestic scale freeze‐dryeracceptedVersio

Differential cross section measurements for the production of a W boson in association with jets in proton–proton collisions at √s = 7 TeV

Measurements are reported of differential cross sections for the production of a W boson, which decays into a muon and a neutrino, in association with jets, as a function of several variables, including the transverse momenta (pT) and pseudorapidities of the four leading jets, the scalar sum of jet transverse momenta (HT), and the difference in azimuthal angle between the directions of each jet and the muon. The data sample of pp collisions at a centre-of-mass energy of 7 TeV was collected with the CMS detector at the LHC and corresponds to an integrated luminosity of 5.0 fb[superscript −1]. The measured cross sections are compared to predictions from Monte Carlo generators, MadGraph + pythia and sherpa, and to next-to-leading-order calculations from BlackHat + sherpa. The differential cross sections are found to be in agreement with the predictions, apart from the pT distributions of the leading jets at high pT values, the distributions of the HT at high-HT and low jet multiplicity, and the distribution of the difference in azimuthal angle between the leading jet and the muon at low values.United States. Dept. of EnergyNational Science Foundation (U.S.)Alfred P. Sloan Foundatio

Penilaian Kinerja Keuangan Koperasi di Kabupaten Pelalawan

This paper describe development and financial performance of cooperative in District Pelalawan among 2007 - 2008. Studies on primary and secondary cooperative in 12 sub-districts. Method in this stady use performance measuring of productivity, efficiency, growth, liquidity, and solvability of cooperative. Productivity of cooperative in Pelalawan was highly but efficiency still low. Profit and income were highly, even liquidity of cooperative very high, and solvability was good

Juxtaposing BTE and ATE – on the role of the European insurance industry in funding civil litigation

One of the ways in which legal services are financed, and indeed shaped, is through private insurance arrangement. Two contrasting types of legal expenses insurance contracts (LEI) seem to dominate in Europe: before the event (BTE) and after the event (ATE) legal expenses insurance. Notwithstanding institutional differences between different legal systems, BTE and ATE insurance arrangements may be instrumental if government policy is geared towards strengthening a market-oriented system of financing access to justice for individuals and business. At the same time, emphasizing the role of a private industry as a keeper of the gates to justice raises issues of accountability and transparency, not readily reconcilable with demands of competition. Moreover, multiple actors (clients, lawyers, courts, insurers) are involved, causing behavioural dynamics which are not easily predicted or influenced. Against this background, this paper looks into BTE and ATE arrangements by analysing the particularities of BTE and ATE arrangements currently available in some European jurisdictions and by painting a picture of their respective markets and legal contexts. This allows for some reflection on the performance of BTE and ATE providers as both financiers and keepers. Two issues emerge from the analysis that are worthy of some further reflection. Firstly, there is the problematic long-term sustainability of some ATE products. Secondly, the challenges faced by policymakers that would like to nudge consumers into voluntarily taking out BTE LEI

Search for stop and higgsino production using diphoton Higgs boson decays

Results are presented of a search for a "natural" supersymmetry scenario with gauge mediated symmetry breaking. It is assumed that only the supersymmetric partners of the top-quark (stop) and the Higgs boson (higgsino) are accessible. Events are examined in which there are two photons forming a Higgs boson candidate, and at least two b-quark jets. In 19.7 inverse femtobarns of proton-proton collision data at sqrt(s) = 8 TeV, recorded in the CMS experiment, no evidence of a signal is found and lower limits at the 95% confidence level are set, excluding the stop mass below 360 to 410 GeV, depending on the higgsino mass