692 research outputs found
Structural damage assessment as an identification problem
Damage assessment of structural assemblies is treated as an identification problem. A brief review of identification methods is first presented with particular focus on the output error approach. The use of numerical optimization methods in identifying the location and extent of damage in structures is studied. The influence of damage on eigenmode shapes and static displacements is explored as a means of formulating a measure of damage in the structure. Preliminary results obtained in this study are presented and special attention is directed at the shortcomings associated with the nonlinear programming approach to solving the optimization problem
Reel and sheet cutting at a paper mill
This work describes a real-world industrial problem of production planning and cutting optimization of reels and sheets, occurring at a Portuguese paper mill. It will focus on a particular module of the global problem, which is concerned with the determination of the width combinations of the items involved in the planning process: the main goal consists in satisfying an order set of reels and sheets that must be cut from master reels. The width combination process will determine the quantity/weight of the master reels to be produced and their cutting patterns, in order to minimize waste, while satisfying production orders.
A two-phase approach has been devised, naturally dependent on the technological process involved. Details of the models and solution methods are presented. Moreover some illustrative computational results are included
Inter-core crosstalk in weakly coupled MCFs with arbitrary core layout and the effect of bending and twisting on the coupling coefficient
We investigate the bending and twisting-induced longitudinal variation of the inter-core coupling coefficient (ICCC) and its effect on inter-core crosstalk (ICXT) in weakly coupled multi-core fibers (MCFs) with an arbitrary core layout. An analytical discrete changes model (DCM) for ICXT field propagation under those conditions is proposed for the first time, providing very fast and rather accurate mean ICXT power estimates. The analytical mean ICXT power estimates are validated through numerical simulation. It is predicted that the mean ICXT power between adjacent cores of the outer ring of the 19-core MCF can be more than 10 dB higher than the one between adjacent cores of the inner ring. It is also predicted that the difference between the mean ICXT power of cores in the inner and outer rings can be much smaller by decreasing the core pitch and increasing the bending radius. This behavior is attributed to the ICXT dependence on the bending and twisting-induced longitudinal variation of the ICCCs. In particular, larger bending and twisting-induced fluctuations of the ICCCs along the longitudinal coordinate are observed in the cores of the outer ring, but the fluctuations become smaller for smaller core pitches and larger bending radii. Furthermore, it is shown that, if the ICCCs’ longitudinal variation is neglected, the mean ICXT power estimates between two adjacent cores are very similar despite the location of those cores. This means that neglecting the longitudinal variation of the ICCCs can lead to misleading estimates of the mean ICXT power, with an error exceeding 15 dB.info:eu-repo/semantics/publishedVersio
Dual polarization discrete changes model of inter-core crosstalk in multi-core fibers
The discrete changes model (DCM) of inter-core crosstalk (ICXT) in weakly-coupled homogeneous multi-core fibers (MCFs) is generalized to a dual polarization (DP) scheme. This model provides theoretical expressions for the two polarization fields of the ICXT at the MCF output. Therefore, it may be of particular interest in the design of direct-detection MCF systems, where the photodetected ICXT results mainly from the beating between the ICXT field at the MCF output and the carrier of the interfered core. The DP-DCM is validated by comparison of the mean ICXT power and ICXT field amplitude estimates with the ones obtained with a rigorous, yet much more computationally demanding, model based on the coupled local mode theory (CLMT). Good agreement between the mean ICXT power estimates obtained with the DP-DCM and CLMT is observed when the inter-core coupling coefficient variation along the MCF is small. Good agreement is also observed when comparing the probability density functions of the ICXT field amplitude
Phosphorus supply for the establishment of palisade grass and forage peanut grown in association.
Fósforo (P) é um nutriente-chave para o estabelecimento de consórcio de gramíneas e leguminosas forrageiras. O objetivo deste trabalho foi determinar a necessidade de P para o estabelecimento de capim-braquiarão e amendoim forrageiro cultivados em associação sob condições controladas. Um experimento de vasos foi conduzido em casa de vegetação usando o delineamento em blocos completos ao acaso com oito tratamentos e quatro repetições. Os tratamentos foram as seguintes doses de P: 0 mg dm-3 (controle), 80 mg dm-3, 160 mg dm-3, 240 mg dm-3, 320 mg dm-3, 400 mg dm-3 e 560 mg dm-3 [fonte: Ca(H2PO4)2.H2O]. Capim-braquiarão (Urochloa brizantha 'Marandu') e amendoim forrageiro (Arachis pintoi 'BRS Mandobi') foram cultivados por 24 dias depois do corte de uniformização e então cortados a 10 cm de altura para determinação da matéria seca do topo da planta. O suprimento adequado de P para o crescimento do topo da planta diferiu entre as espécies. Capim-braquiarão necessitou de 80 mg dm-3 de P, ao passo que 160 mg dm-3 de P foram exigidos pelo amendoim forrageiro. O amendoim forrageiro necessitou de mais P do que o capim-braquiarão para o estabelecimento de ambas as espécies cultivadas em associação sob condições controladas
Preferência para oviposição de Telenomus podisi (Ashmead) (Hymenoptera: Scelionidae) por ovos de Glyphepomis nov. sp. Berg, 1891 (Hemiptera: Pentatomidae) de diferentes idades de desenvolvimento embrionário.
Telenomus podisi parasita ovos de diferentes espécies de percevejos da família Pentatomidae. Glyphepomis nov. sp., trata-se de uma nova espécie de percevejo na cultura do arroz no Brasil. Nesse sentido, estudos visando avaliar a capacidade reprodutiva de parasitoides são fundamentais tendo em vista que o desenvolvimento destes em ovos de seus hospedeiros que se encontram no inicio ou no final do desenvolvimento embrionário podem afetar a sua sobrevivência. Portanto, o objetivo da pesquisa foi conhecer a preferência para oviposição de T. podisi por ovos de Glyphepomis nov. sp. de diferentes idades de desenvolvimento embrionário
Application of Artificial Neural Networks and Hybrid Methods in the Solution of Inverse Problems
Experimental Chemotherapy for Chagas Disease: A Morphological, Biochemical, and Proteomic Overview of Potential Trypanosoma cruzi Targets of Amidines Derivatives and Naphthoquinones
Chagas disease (CD), caused by Trypanosoma cruzi, affects approximately eight million individuals in Latin America and is emerging in nonendemic areas due to the globalisation of immigration and nonvectorial transmission routes. Although CD represents an important public health problem, resulting in high morbidity and considerable mortality rates, few investments have been allocated towards developing novel anti-T. cruzi agents. The available therapy for CD is based on two nitro derivatives (benznidazole (Bz) and nifurtimox (Nf)) developed more than four decades ago. Both are far from ideal due to substantial secondary side effects, limited efficacy against different parasite isolates, long-term therapy, and their well-known poor activity in the late chronic phase. These drawbacks justify the urgent need to identify better drugs to treat chagasic patients. Although several classes of natural and synthetic compounds have been reported to act in vitro and in vivo on T. cruzi, since the introduction of Bz and Nf, only a few drugs, such as allopurinol and a few sterol inhibitors, have moved to clinical trials. This reflects, at least in part, the absence of well-established universal protocols to screen and compare drug activity. In addition, a large number of in vitro studies have been conducted using only epimastigotes and trypomastigotes instead of evaluating compounds' activities against intracellular amastigotes, which are the reproductive forms in the vertebrate host and are thus an important determinant in the selection and identification of effective compounds for further in vivo analysis. In addition, due to pharmacokinetics and absorption, distribution, metabolism, and excretion characteristics, several compounds that were promising in vitro have not been as effective as Nf or Bz in animal models of T. cruzi infection. In the last two decades, our team has collaborated with different medicinal chemistry groups to develop preclinical studies for CD and investigate the in vitro and in vivo efficacy, toxicity, selectivity, and parasite targets of different classes of natural and synthetic compounds. Some of these results will be briefly presented, focusing primarily on diamidines and related compounds and naphthoquinone derivatives that showed the most promising efficacy against T. cruzi
[religion And Psychiatric Disorders In Patients Admitted To A University General Hospital].
In order to evaluate the prevalence of psychiatric disorders in a Brazilian general hospital and their association with religious denomination and religiosity, 253 inpatients were interviewed. A socio-demographic questionnaire and an instrument for diagnosis of mental disorders (MINI-Plus) were applied. Distribution of religious denominations was: Catholic 63.2% (n=177), Evangelical Protestant 20.4% (n=57), Spiritist 4.3% (n=12), traditional Protestant 2.3% (n=8), and no religion 7.5% (n=21). Degree of religiosity was: very religious 43.2% (n=116), religious 46.9% (n=129), hardly religious 9.8% (n=27), and not at all religious 1.1% (n=3). Evangelical (Pentecostal) religious affiliation and frequent attendance at worship services were associated with fewer alcohol problems. Membership in an Evangelical (Pentecostal) church may thus have an inhibitory effect on alcohol dependence or abuse. Intensity of religiosity was moderately associated with overall prevalence of disorders, especially bipolar disorder. It is reasonable to conclude that extreme situations (very intense versus very limited religious participation) are related to this finding, associating both an exacerbated pursuit of religion and alienation from it with altered mental states.24793-
Intimate Partner Violence in Urban, Rural, and Remote Areas: An Investigation of Offense Severity and Risk Factors
This study compared the severity of intimate partner violence (IPV) and the relationship between risk factors for IPV and overall risk judgements of future IPV in urban, rural and remote areas. IPV risk assessments conducted by the Swedish police between 2010 and 2014 in urban (n = 564), rural (n = 456), and remote (n = 196) areas were examined. Rurality was associated with the severity of IPV reported, as well as the presence of risk factors and their relationship to overall risk judgements. Cases in remote areas included more severe IPV as well as more risk factors
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