Transmission expansion in Argentina 5: The regional electricity forum of Buenos Aires province

This paper supplements analyses of Argentine transmission expansions at the federal level by looking at experience in Buenos Aires province. A Regional Electricity Forum of distribution companies has drawn up and begun to implement a 10-year transmission expansion plan. Contrary to previous fears, getting agreement between the members on investment and cost sharing has not been unduly problematic. More challenging was getting approval of the provincial government on funding. Deferring tariff reductions and using the revenues for investment facilitated the process, and now some innovative financing arrangements are underway. Again contrary to some previous suggestions, the controversial Area of Influence method was extended rather than replaced. This overcame concerns about free-riding. Progress and investment have been severely curtailed by the economic crisis in 2001 and subsequent federal government policy. The arrangements nonetheless appear to be working well, and to be conducive to more efficient transmission expansion. This confirms that it is practicable and advantageous to allow users rather than the transmission company or the regulator to propose and determine transmission investment, even in a meshed rather than radial system. An appropriate regulatory framework is needed to approve that part of the total budget to paid by distribution business consumers, but this does not require the regulator to lead or monitor the detail of the process.     

Study of the anti-lactic acid bacteria compounds in table olives

The analysis and formation of anti-lactic acid bacteria compounds in olive brines was performed for the main worldwide olive varieties intended for table olives. The results demonstrated that the growth of lactic acid bacteria in the brines of olives non-treated with NaOH is, in some way, variety dependant. Likewise, the most active antimicrobial compound, the dialdehydic form of decarboxymethyl elenolic acid linked to hydroxytyrosol, was not detected in fresh fruits but it was formed during brining from the hydrolysis of oleuropein and this reaction was enzymatically catalysed. Thus, the inactivation of the enzyme by heating the olives produced (i) an accumulation of oleuropein in olives and brines, (ii) the inhibition of the formation of antimicrobials and (iii) the growth of Lactobacillus pentosus in olive brines. These results provide tools for a full understanding of the growth or inhibition of lactic acid bacteria during fermentation of table olives.     

CdTe/CdS core shell quantum dots for photonic applications

In this work, we show a simple experimental procedure to obtain CdTe/CdS (diameter=3-7 nm) core shell nanocrystals in colloidal suspension. The nanocrystals were characterized by transmission electronic microscopy and powder X-ray diffraction analysis. The optical properties were determined by electronic absorption, excitation and emission spectroscopies and are discussed in terms of chemical changes that occur at the surface of the particles.     

Archictecture and Performance of Java-Based Distributed Object Models: CORBA vs RMI

This paper presents a comprehensive comparison of thearchitectural differences and similarities of the two most popularJava-based distributed object models: RMI and CORBA. Performanceand timing issues related to the CORBA and RMI architecturesare also considered. The following aspects are studied for clientserver applications, on Sun UltraSparcs under Solaris 2.5.1 andPentium II under Windows NT 4.0: response time for method invocationwithout parameters as well as with variable number of parameters;response time for applet clients, and response time for variablenumber of clients requesting the same service. The goal is toprovide a reference framework that supports the selection ofeither mechanism for the development of web-based distributedreal-time applications: chat programs, interactive games, sharedboards, etc.     

A systematic review of domain analysis tools

The domain analysis process is used to identify and document common and variable characteristics of systems in a specific domain. In order to achieve an effective result, it is necessary to collect, organize and analyze several sources of information about different applications in this domain. Consequently, this process involves distinct phases and activities and also needs to identify which artifacts, arising from these activities, have to be traceable and consistent. In this context, performing a domain analysis process without tool support increases the risks of failure, but the used tool should support the complete process and not just a part of it. This article presents a systematic review of domain analysis tools that aims at finding out how the available tools offer support to the process. As a result, the review identified that these tools are usually focused on supporting only one process and there are still gaps in the complete process support. Furthermore, the results can provide insights for new research in the domain engineering area for investigating and defining new tools, and the study also aids in the identification of companies’ needs for a domain analysis tool.     

Analysis and design of networked control systems using the additive noise model methodology

Networked Control has emerged in recent years as a new and exciting area in systems science. The topic has many potential applications in diverse areas ranging from control of microrobots to biological and economic systems. The supporting theory is very rich and combines aspects of control, signal processing, telecommunications, and information theory. In this paper, we give a partial overview of recent developments in Networked Control with an emphasis on the additive noise model methodology. We also point to several open problems in this emerging area. Copyright © 2010 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society     

双侧延伸端板半刚性组合节点的抗震性能(1):试验研究

与钢结构相比,相同延性下,组合结构具有较高的刚度及较好的抗火性能。因此,在地震高发区大量采用组合结构。研究了双侧延伸端板半刚性组合节点的抗震性能,对节点进行单调、循环、准静力试验,以描述这种节点的抗震性能。试验包括内节点和外节点,并提供了关于节点延性、能量耗散、退化影响的实用数据。采用这些数据构建和校验基于构件的节点模型。节点由双向弹簧组成,其中一个代表剪切板的性能,另一个代表连接的性能。模型能精确模拟节点的性能及在循环荷载下的破坏形式。     

CONTINUITY BETWEEN DISORDER AND ORDER IN THE SEQUENTIAL DEPOSITION OF PARTICLES

In previous work we pointed out that clusters of particles built through sequential quenching show increasing degrees of order as the temperature is lowered. In the low-temperature limit, a two-dimensional model system with a nondegenerate ground state would result in a perfect crystal. The opposite, high-temperature, limit corresponds to the case of random sequential addition (RSA). In the present work we study the continuous evolution from disorder to order at intermediate states using a triangular well potential to represent particle interactions. We investigate radial and bond-orientation correlation functions and the bond order parameter as measures of the degree of crystallinity of the structures up to a reduced number density of 0.65, which is close to the jamming limit of RSA.     

Regional disparities and determinants of growth in Mexico

Developing countries such as Mexico, in which profound processes of economic liberalization have taken place over the last few decades, offer fertile terrain for studies of regional disparities. Mexico has experienced a history of polarization between regions, the industrialized north and the underdeveloped south, which have seen their differences widen, exacerbated through recurrent crises and liberalization processes. This paper looks at the convergence process among regions, examining which factors might affect regional growth, tracking the evolution of single units and identifying winners and losers. The evidence shows that northern states, bordering the USA, moved from a condition that might be described as `falling-behind' prior to liberalization to that of a `winner' after that process, while southern states went from the position of `catching-up' to that of `loser'. Regional disparities in human capital would appear to be playing a decisive role in the existence of differences. The author acknowledges comments from Gilles Duranton, Henry Overman, Andrés Rodríguez-Pose, two anonymous referees, and participants in seminars in The London School of Economics and the European University Institute.     

Variable Formulation Search for the Cutwidth Minimization Problem

Many optimization problems are formulated as min–max problems where the objective function consist of minimizing a maximum value. In this case, it is usual that many solutions of the problem has associated the same value of the objective function. When this happens it is difficult to determine which solution is more promising to continue the search. In this paper we propose a new variant of the Variable Neighbourhood Search methodology to tackle this kind of problems. The new variant, named Variable Formulation Search, makes use of alternative formulations of the problem to determine which solution is more promising when they have the same value of the objective function in the original formulation. We do that in shaking, local search and neighbourhood change steps of the basic Variable Neighbourhood Search. We apply the new methodology to the Cutwidth Minimization Problem. Computational results show that our proposal outperforms previous algorithms in the state of the art in terms of quality and computing time.