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This study aims to investigate the water spray uniformity and collection ratio of sprinkler in an evaporative condenser of a water chiller. Experiments of water droplet distribution are conducted with 50 water collectors during the tests. Three different combinations of nozzle opening length and width were tested with the flow rates varied at 135 LPM and 176.4 LPM. Measured results show that the cross-sectional area of nozzle opening and flow rate significantly affect the water spray uniformity. In this work, at high flow rate, the Nozzle 2 with opening of 4 cm in length and 1 cm in width has better water spray uniformity compared to the nozzle 1 with opening of 4 cm in length and 0.7 cm in width. On the other hand, at low flow rate, the Nozzle 1 provides better impacting effect with the nozzle spacing of 17 cm, yet the Nozzle 2 performed better with the nozzle spacing of 15 cm. The latter case, with the smaller nozzle spacing and bigger nozzle opening size, led to a shorter impact distance of the spraying flow from two facing nozzles. Subsequently the spattering of water droplets was more pronounced, and distributed more uniformly. Keywords: Water spray uniformity, Collection ratio of sprinkler, Evaporative condenser, Nozzle opening

This paper presents several advances for the PMU placement problem (PPP). Existing approaches have difficulty scaling to full-scale systems, and are not guaranteed to be resilient to multiple component failures. This paper expands PPP to a more general k-resilient PPP, where any k PMUs and/or lines can fail without jeopardizing the problem's full supervision criterion. Our PPP model — a novel formulation based on maximum-flow network design — is unique in that it is amenable to efficient decomposition, which significantly improves tractability and scalability. We present two cutting plane algorithms to support this decomposition — the first such algorithms for the PPP to our knowledge. The improvements in computational efficiency afforded by the network decomposition suggest that our approach can solve the PPP for large-scale systems.

This article establishes a new family of methods to perform temperature interpolation of nuclear interactions cross sections, reaction rates, or cross sections times the energy. One of these quantities at temperature T is approximated as a linear combination of quantities at reference temperatures (Tj). The problem is formalized in a cross section independent fashion by considering the kernels of the different operators that convert cross section related quantities from a temperature T0 to a higher temperature T namely the Doppler broadening operation. Doppler broadening interpolation of nuclear cross sections is thus here performed by reconstructing the kernel of the operation at a given temperature T by means of linear combination of kernels at reference temperatures (Tj). The choice of the L2 metric yields optimal linear interpolation coefficients in the form of the solutions of a linear algebraic system inversion. The optimization of the choice of reference temperatures (Tj) is then undertaken so as to best reconstruct, in the L sense, the kernels over a given temperature range [Tmin,Tmax]. The performance of these kernel reconstruction methods is then assessed in light of previous temperature interpolation methods by testing them upon isotope 238U. Temperature-optimized free Doppler kernel reconstruction significantly outperforms all previous interpolation-based methods, achieving 0.1% relative error on temperature interpolation of 238U total cross section over the temperature range [300K,3000K] with only 9 reference temperatures. Developed cross section independent methods to perform temperature interpolation as L2 kernel reconstruction optimization problems.A cross section is approximated as a linear combination of reference temperatures cross sections.L2 norm is physically justified, yielding formulae for optimal interpolation coefficients.Optimal reference temperature grids are developed.Kernel reconstruction significantly outperforms previous temperature interpolation methods.

Due to the uncertainty and fluctuation of distributed generation (DG) and load, the operation of active distribution network (ADN) is affected by multi-dimension factors which are described by massive operation scenarios. Efficient and accurate screening of severely restricted scenarios (SRSs) has become a new challenge in ADN planning. In this paper, a novel bi-level coordinated planning model which combines the short-time-scale operation problem with the long-time-scale planning problem is proposed. At the upper level, the demand response (DR) resource, an effective non-component planning resource characterized by low capacity price, high energy price, and short contract term, is co-optimized with the configuration of lines and energy storage systems (ESSs) to achieve the economic trade-off between the investment cost and the operation cost under SRSs. At the lower level, with the planning scheme obtained from the upper level, massive operation problems are optimized to minimize the daily operation cost; and the SRSs are provided to the upper level through a shadow-price-based scenario screening method, which simulates the planning information (i.e., the restricted degrees of operation scenarios) feedback process from ADN operators to ADN planners. Case studies on a 62-node distribution system in Jianshan New District, Zhejiang Province, China, illustrate the effectiveness of the proposed bi-level coordinated planning model considering DR resources and SRSs.

Abstract: Lithuania, one of the three Baltic states, is among the countries in Europe that are currently facing the challenge of implementing a newly codified private law. Lithuania was the first former Soviet Republic to gain its independence in 1990. Ten years later, the Republic of Lithuania adopted a new civil code. It entered into force in July 2001 and is currently one of the most recent examples of an entirely new private law codification in Europe. This article retraces the role of the comparative legal method in the procedure of drafting the new codification. It further discusses the role of the comparative method when it comes to applying the new Code, focusing on the case law of the Supreme Court of Lithuania. The development in Lithuania shows, on the one hand, the benefits that can be gained when lawmakers use the comparative method in the process of preparing new codifications. On the other hand, the situation in Lithuania illustrates the challenges courts and judges face when it comes to using this method in applying the newly introduced codes and statutes. Résumé: La Lituanie, un des trois pays baltes, est parmi les pays d'Europe centrale et d'Europe de l'Est faisant actuellement face à la tâche de mettre en oeuvre de nouvelles codifications de droit privé. En 1990, la Lituanie était la première des anciennes républiques soviétiques à regagner son indépendance. Dix ans plus tard, la République de Lituanie a adopté un nouveau code civil. Il est entré en vigueur le 1er juillet 2001 et compte aujourd'hui parmi les plus récents exemples d'une toute nouvelle codification de droit privé en Europe. La contribution suivante retrace le rôle de la méthode comparative lors de la préparation du Code civil lituanien. Ensuite, elle analyse le rôle du droit comparé dans la mise en pratique de ce nouveau Code, en mettant l'accent sur la jurisprudence de la Cour Suprême de Lituanie. La situation en Lituanie illustre, d'une part, les bénéfices qui peuvent être tirés de l'emploi de la méthode comparative par le législateur; elle montre, d'autre part, les défis que présente l'emploi de cette méthode pour les tribunaux quand il s'agit de mettre en oeuvre le nouveau Code civil.

Artículos en revistas Islands are facing considerable challenges in meeting their energy needs in a sustainable, affordable and reliable way. The present paper develops an integrated approach to economically assess initiatives that can transform island power systems into smart ones. Single and multi-action initiatives fostering the deployment of renewable energy sources (RES), energy storage systems (ESS), demand-side management (DSM), and electric vehicle (EV) are considered. An hourly unit commitment on a weekly basis is proposed to assess the impact of the initiatives on the system operation costs of five prototype island power systems, which have been identified by applying clustering techniques to a set of sixty islands power systems. The different investment costs of the initiatives are accounted for determining their corresponding internal rate of return (IRR) through their lifetime. The economic assessment of single and multi-action initiatives for five prototype islands representing sixty island power systems quantifies which initiatives are most suitable for which type of island power system. The assessment shows that islands of different sizes and features require different initiatives. Larger islands tend to DSM initiatives, whereas smaller islands tend to RES initiatives. Multi-action initiatives achieve highest system operation cost reduction, whereas single action initiatives yield to highest IRR. info:eu-repo/semantics/publishedVersion

GDI injection systems have become dominant in passenger cars due to their flexibility in managing and advantages in the fuel economy. With the increasingly stringent emissions regulations and concurrent requirements for enhanced engine thermal efficiency, a comprehensive characterization of the fuel spray behavior has become essential. Different engine loads produce in a variety of fuel supplying conditions that affect the air/fuel mixture preparation and influence the efficiency and pollutant production. The flash boiling is a particular state that occurs for peculiar thermodynamic conditions of the engine. It could strongly influence the mixture in subatmospheric environments with detrimental effects on emissions. In order to obtain an in-depth understanding of the flash boiling phenomena, it is necessary to study the parameters influencing the mixture formation and their appearance in diverse engine conditions. The objective of this study is to investigate the effect of the ambient pressure and temperature on the morphology of a multi-jet spray operating in flash boiling status using a Gasoline Direct Injection setup. An eight-hole, GDI injector from the Engine Combustion Network (ECN), was investigated under flashing and non-flashing conditions. The experiments were performed in an opticallyaccessible, constant-volume vessel at engine-like conditions. A hybrid optical setup, Z-type schlieren and Mie scattering, using a high-speed C-Mos camera allowed the quasi-simultaneous acquisition of both the vapor and the liquid phases. A customized image-processing procedure, developed in Matlab environment, was used to outline the contours of both the fuel phases. Different morphologies of the fuel spray were studied as function of the injection pressure, the fuel temperature, and the backpressure in the vessel, through the measurement of the axial penetration and cone angle