1,720,983 research outputs found
Long-term clinical consequences of urinary tract infections during childhood: A review
No full textKidney scarring related to urinary tract infection in childhood has been considered the cause of serious long-term clinical consequences. This assumption is now debated, as the advent of routine antenatal ultrasound in the 1980s has shown that a consistent part of the changes previously attributed to postinfectious scarring is mainly due to congenital malformations. With the aim of determining what is presently known on the long-term clinical consequences of urinary tract infections (UTIs) in childhood, we performed a review of the literature on the relation between UTIs and blood pressure, renal function, growth and pregnancy-related complications. By searching Medline/PubMed and Embase from 1980 to 2011, we identified 20 cohorts of children from 23 papers. Conclusions: Renal function: there are no clear data to establish long-term consequences following UTIs during childhood. Most data seem to show that the outcome of renal function can already be delineated at first presentation or in the initial years of follow-up; only 0.4% of children with normal renal function at start presented a decrease during follow-up. Hypertension: there is a low risk, associated with renal damage. Growth and pregnancy-related complications: the few available data seem to exclude a major influence of UTIs. © 2012 Foundation Acta Pædiatrica
Using Experimental Data for Predicting Performance and Emissions of a Real Gas Turbine Plant
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Cost Evaluation of Organic Rankine Cycles for Low Temperature Geothermal Sources
No full textOrganic Rankine cycles are now a mature technology for the conversion of low temperature geothermal sources into electricity. This paper deals with the evaluation of the levelized cost of electricity of the binary cycle power plants that have been optimized according to a pure thermodynamic objective in a previous work. Geothermal fluid inlet temperatures in the range 130-180°C are considered here and both super- and s ubcritical solutions are taken into account. The purchase costs for all plant components and subcomponents are evaluated using standard functions that can be found in the literature. Installation and indirect costs are also taken into account to obtain the overall cost of the plant. The relationships used are validated on
aggregated economic data available from a real geothermal binary power plant that is used as reference. The levelized cost of electricity is finally calculated from the overall cost of the plant and its annual energy production
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
An Organic Rankine Cycle off-design model for the search of the optimal control strategy
No full textPower generation from low enthalpy geothermal resources using Organic Rankine Cycle systems is markedly influenced by the temperature level of the heat source and heat sink. During plant operation the actual temperature of the geofluid may be different from the value assumed in the design phase. In addition, the seasonal and daily variations of the ambient temperature greatly affect the power output especially when a dry condensation system is used. This paper presents a detailed off-design model of an Organic Rankine Cycle that includes the performance curves of the main plant components. Two capacitive components in the model have the key function of damping the temporary disequilibrium of mass and energy inside the system. Isobutane and R134a are considered as working fluids, mainly operating in subcritical and supercritical cycles, respectively. The off-design model is used to find the optimal operating parameters that maximize the electricity production in response to changes of the ambient temperatures between 0 and 30°C and geofluid temperatures between 130 and 180°C. This optimal operation strategy can be conveniently applied both to already existing plants and in the choice of new design plant configurations
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Methodological aspects in synthesis of combined sugar and ethanol production plant
No full textThe synthesis problem, i.e. the definition of type, number and design parameters of system components
and their interconnections, is one of the main research field of chemical and energy engineering. The
present paper aims at clarifying some methodological aspects for the systematic synthesis of processes
by suggesting an organized procedure which is applied here to a case study of a sugarcane mill. The
procedure starts from the definition of a Basic Plant Configuration (BPC) that is built according to the
original “concept” of the conversion process (e.g., “transform sugarcane into sugar” or “transform
sugarcane into sugar and ethanol”). The BPC comprises the “basic components”, i.e. those required to
perform the main material and energy conversions, and considers the hot and cold thermal flows only
instead of the heat exchangers. A design optimization of this configuration is then to be performed, in
which the extreme temperature of the thermal streams are considered among the set of the decision
variables. The original BPC is then progressively changed into new BPCs by means of structural modifications
including component staging and addition of new material connections or subprocesses.
Modifications to the original BPC are mainly derived from the interpretation of the process Grand
Composite Curve (GCC), a graphical tool provided by Pinch Analysis, which helps identify the potential
for process internal heat recovery. Although the development of an automated algorithm is the final goal
of the research activities, this article aims at showing that the proposed approach can be used to
systematically explore the most significant process synthesis options. In the light of the suggested
procedure we investigate here three different process concepts for the conversion of sugarcane. Starting
from the original concept of sugar production, process structural developments towards the combined
sugar and ethanol production are proposed and discussed
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