Search results for "EXPANSION"

Distraplan: a flexible tool for strategical planning of electrical distribution systems considering distributed generation.

2005

The paper here presented describes and shows DISTRAPLAN (Distribution Strategical Planning), software tool for strategical planning of distribu tion networks at Medium and Low voltage. The software aims at the identification and comparison of network configur ations, optimized in the long term with identification of special features in relation to the main technical-economical-environmental aspects, such as: the number of HV/MV and MV/LV substations, total length of the MV and LV lines and relevant sections, maximum required energy and power, instal lation and losses costs, etc. DISTRAPLAN, in both the main procedures into which it is articulated (strategical planning and evaluation of the …

Structural behavior of the old masonry bridge in the Gulf of Castellammare

2016

Abstract Masonry arch bridges represent a very significant part of the heritage of road and railway artworks all over the word and especially in the Mediterranean area, both in terms of: numbers; reduced environmental impact; and static efficiency. In these cases, the cost of maintenance is often limited to the content and channeling of surface water and control of vegetation, which can eventually take root on the joints of the masonry at the shoulders. In masonry bridges, there are no expansion joints or hinges with support equipment or trolleys, as in metal bridges and reinforced concrete ones, or paint, or resin surface protection, all items that affect the cost of maintenance. The perma…

Material characteristics in the analysis of heated steel beams

1989

Beam fire tests are expensive and complicated. They may be replaced by calculations of the heated beam deflection by means of the method presented in this paper. The following material characteristics in the analysis of the deflection of beams during fire may be taken as fundamental: the steel creep characteristic at elevated temperatures, the modulus of elasticity and the coefficient of thermal expansion. According to the yield hinge theory, the yield stress is the criterion of failure of steel beams in fire. On the other hand, in the analysis of the deflection of the heated steel beams the influence of the yield stress is very small. The influence of the respective material characteristic…

Bubble formation at variously inclined nozzles

2014

Bubble formation at variously inclined submerged nozzles, fed with a continuous gas flow rate, is investigated. Results confirm previous findings, such as a substantial independence of bubble size of nozzle diameter and its dependence on the cubic root of gas flow rate at sufficiently high values of this parameter. Nozzle inclination in the range between 0 and 135° from the vertical upward orientation is found to have a negligible effect on bubble size. Observed bubble rise velocities lead to an estimation of the average liquid velocity induced by bubbles motion, leading in turn to a very simple correlation for the estimation of the liquid velocities induced by the repeated passage of bubbl…

Comparison of thermal expansion of wood and epoxy adhesives

2002

Epoxy-based adhesives are used both in the consolidation of decayed timbers and for new structural joints. Investigating the compatibility of wood and epoxy adhesives provides a better knowledge of the long-term behaviour of wood-epoxy joints. Besides mechanical compatibility, also temperature-related parameters are relevant in this context. The values of the thermal expansion coefficients (TEC) of two wood species (Spruce, Picea abies and Iroko, Clorophora excelsa) and four different epoxy resins have been compared using a modified test method that allows for nearly iso-hygric conditions of the wood specimens. Minor differences in TEC have been observed between wood in the transversal-to-t…

On the equation of state for thermal polymer solutions and melts with attractive interaction

1996

We perform Monte Carlo simulations of a lattice model for polymer melts, i. e., the bond fluctuation model in three dimensions. By using an energy parameter that prefers relatively long bonds, the model exhibits a glass transition at low temperatures, in close qualitative similarity to experiment. We modify this model by adding an attractive interaction of variable strength. We demonstrate that a small interaction strength has only a very small effect on the static properties of the melt. For a fixed strength of the potential, the chemical potential is measured by a modified particle-insertion method over a large range of temperatures and densities. The osmotic pressure is obtained by therm…

Measurements of aerosol size distributions with a pocket counter with variable expansion ratio

2008

Expansion of private secondary education : lessons from recent experience in Tanzania

2000

International audience; The private sector's role in education has been the subject of much analysis and policy debate in recent years. In developing countries, public resources for education are limited and governments have traditionnally relied on private education, particularly at the post-basic levels, to meet the excess demand for education. Even when excess demand is not a major issue, advocates of private education note that private schools can be more efficient than their public sector counterparts, delivering more value in terms of student achievement per investment of resources. In this article we explore Tanzania's experience with private education during the early 1990s, a perio…

U.S. Expansionism, Mexican Undocumented Migration, and American Obligations

2011

In his compelling piece, “Living in a Promiseland? Mexican Immigration and American Obligations,” Rogers Smith argues that the greater the degree to which the U.S. has coercively constituted the identities of non-citizens in ways that have made having certain relationships to America fundamental to their capacities to lead free and meaningful lives, the greater the obligations the U.S. has to facilitate those relationships. Over the last hundred years, many rural communities in Mexico have been constituted more by U.S. immigration policy and the labor demands of U.S. employers than by similar policies and economic factors in Mexico. According to Smith, this means that Mexicans may be owed “…

Bildungsexpansion, soziale Klasse und die Wahl von Latein als Strategie der Distinktion

2021

In times of educational expansion, privileged families are looking for new strategies of distinction. Referring to Pierre Bourdieu���s theory of distinction, we argue that choosing Latin at school ��� a language that is no longer spoken and therefore has no direct value ��� is one of the strategies of privileged families to set themselves apart from less privileged families. Based on two surveys we conducted at German schools, the paper analyzes the relationship between parents��� educational background and the probability that their child will learn Latin. Results indicate that historically academic families have the strongest tendency towards learning Latin, followed by new academic famil…