2,057 research outputs found

    Development of Optimization Tool for Air Conditioning System Operation

    Get PDF
    This study aims to realize the optimization of the air-conditioning system operation. Although set values of air-conditioning systems are usually fixed, variable setting values are used in this study. It is possible that less energy consumption with greater comfort is achieved by selecting appropriate set values in consideration of situations which change from day to day. In this study, the optimization of air-conditioning system operation is carried out by selecting appropriate set values in terms of energy consumptions and the comfort. The prediction of building heat loads is necessary to realize the optimization in ever-changing environments. Therefore, a more robust optimization method which handles errors in the prediction was proposed, and the optimization tool for an air-conditioning system was developed. The developed optimization tool is incorporated into the Building and Energy Management System (BEMS), and it automatically changes setting values acquiring data including driving data from the BEMS. Experiments were conducted to clarify the effectiveness of the tool, and simulations in the case of a medium-scale office building were also done for the evaluation of the tool. Experiments prove that the evaluation value tends to improve by using the optimization tool. As the result of simulations, it is found out that the evaluation value improves by considering prediction errors and that the evaluation value is reduced by 12.1% at maximum

    Morphological Effects of Glycosaminoglycans on Calcium Oxalate Monohydrate Crystals

    Get PDF
    The effects of individual glycosaminoglycan (GAG) species on calcium oxalate monohydrate (COM) crystal growth were studied in vitro by the observation of crystal morphology grown in a supersaturated calcium oxalate solution in the presence of GAGs using optical and scanning electron microscopes. GAGs affected the morphology of COM crystals differently depending on the species. The growth rates of the crystals formed in the presence of chondroitin-6-sulfate (ChS-C) were higher in length and lower in width and thickness than those of control crystals. The incorporation of dermatan sulfate or heparin into the crystals formed in the presence of these GAGs was revealed by X-ray microanalysis, whereas ChS-C was not detected in the crystals grown with it. The experiment using dicarboxylates, as a simple model of GAG molecules, showed that a distance between the side groups was important for their morphological effects. These findings suggested that the different effects of GAGs on the crystal morphology resulted from the differences in their interaction modes with COM crystal faces, that is, the differences in their binding behavior, their inhibition modes of crystal growth, and other roles played after binding to the crystals

    Macroscopic proof of the Jarzynski-Wojcik fluctuation theorem for heat exchange

    Full text link
    In a recent work, Jarzynski and Wojcik (2004 Phys. Rev. Lett. 92, 230602) have shown by using the properties of Hamiltonian dynamics and a statistical mechanical consideration that, through contact, heat exchange between two systems initially prepared at different temperatures obeys a fluctuation theorem. Here, another proof is presented, in which only macroscopic thermodynamic quantities are employed. The detailed balance condition is found to play an essential role. As a result, the theorem is found to hold under very general conditions.Comment: 9 pages, 0 figure

    Development and Verification for the Control Method Using Surplus Pressure of Primary Pumps in Chiller Plant Systems for Air Conditioning which Adopts Primary/Secondary Piping Systems PPT

    Get PDF
    The primary/secondary piping systems are often employed in large chiller plant Systems. Normally, the primary flow becomes more than secondary flow, and the flow difference returns to a chiller via decoupler, which is common to primary flow loop (chiller side) and secondary flow loop (load side). It is a huge energy loss, because the primary pumps use their head to lead much flow to the decoupler. Therefore, we have developed new control method using surplus pressure of the primary pump to reduce the primary and secondary pumps' energy. In this paper, we used this control method to the actual chiller plant buildings and verified its effectiveness. As a result, cold water conveyances, both primary loop and secondary loop, could be covered by only primary pumps during plant operating time, and the water conveyance power energy was reduced approximately 80%

    A novel type of proximity focusing RICH counter with multiple refractive index aerogel radiator

    Full text link
    A proximity focusing ring imaging Cherenkov detector, with the radiator consisting of two or more aerogel layers of different refractive indices, has been tested in 1-4 GeV/c pion beams at KEK. Essentially, a multiple refractive index aerogel radiator allows for an increase in Cherenkov photon yield on account of the increase in overall radiator thickness, while avoiding the simultaneous degradation in single photon angular resolution associated with the increased uncertainty of the emission point. With the refractive index of consecutive layers suitably increasing in the downstream direction, one may achieve overlapping of the Cherenkov rings from a single charged particle. In the opposite case of decreasing refractive index, one may obtain well separated rings. In the former combination an approximately 40% increase in photon yield is accompanied with just a minor degradation in single photon angular resolution. The impact of this improvement on the pion/kaon separation at the upgraded Belle detector is discussed.Comment: submitted to Nucl. Instr. Meth.

    Microcanonical Foundation for Systems with Power-Law Distributions

    Full text link
    Starting from microcanonical basis with the principle of equal a priori probability, it is found that, besides ordinary Boltzmann-Gibbs theory with the exponential distribution, a theory describing systems with power-law distributions can also be derived.Comment: 9 page

    Complete relativistic equation of state for neutron stars

    Get PDF
    We construct the equation of state (EOS) in a wide density range for neutron stars using the relativistic mean field theory. The properties of neutron star matter with both uniform and non-uniform distributions are studied consistently. The inclusion of hyperons considerably softens the EOS at high densities. The Thomas-Fermi approximation is used to describe the non-uniform matter, which is composed of a lattice of heavy nuclei. The phase transition from uniform matter to non-uniform matter occurs around 0.06fm30.06 \rm{fm^{-3}}, and the free neutrons drip out of nuclei at about $2.4 \times 10^{-4}\ \rm{fm^{-3}}$. We apply the resulting EOS to investigate the neutron star properties such as maximum mass and composition of neutron stars.Comment: 23 pages, REVTeX, 9 ps figures, to appear in Phys. Rev.

    On-site underground background measurements for the KASKA reactor-neutrino experiment

    Get PDF
    On-site underground background measurements were performed for the planned reactor-neutrino oscillation experiment KASKA at Kashiwazaki-Kariwa nuclear power station in Niigata, Japan. A small-diameter boring hole was excavated down to 70m underground level, and a detector unit for γ\gamma-ray and cosmic-muon measurements was placed at various depths to take data. The data were analyzed to obtain abundance of natural radioactive elements in the surrounding soil and rates of cosmic muons that penetrate the overburden. The results will be reflected in the design of the KASKA experiment.Comment: 9 pages, 7 figures, final version for publication. Table 1 and Fig.5 have change
    corecore