Identification of structural damage in flexible structures using system norm and neural networks

Nowadays there is great interest in damage identification using non destructive tests. Predictive maintenance is one of the most important techniques that are based on analysis of vibrations and it consists basically of monitoring the condition of structures or machines. A complete procedure should be able to detect the damage, to foresee the probable time of occurrence and to diagnosis the type of fault in order to plan the maintenance operation in a convenient form and occasion. In practical problems, it is frequent the necessity of getting the solution of non linear equations. These processes have been studied for a long time due to its great utility. Among the methods, there are different approaches, as for instance numerical methods (classic), intelligent methods (artificial neural networks), evolutions methods (genetic algorithms), and others. The characterization of damages, for better agreement, can be classified by levels. A new one uses seven levels of classification: detect the existence of the damage; detect and locate the damage; detect, locate and quantify the damages; predict the equipment's working life; auto-diagnoses; control for auto structural repair; and system of simultaneous control and monitoring. The neural networks are computational models or systems for information processing that, in a general way, can be thought as a device black box that accepts an input and produces an output. Artificial neural nets (ANN) are based on the biological neural nets and possess habilities for identification of functions and classification of standards. In this paper a methodology for structural damages location is presented. This procedure can be divided on two phases. The first one uses norms of systems to localize the damage positions. The second one uses ANN to quantify the severity of the damage. The paper concludes with a numerical application in a beam like structure with five cases of structural damages with different levels of severities. The results show the applicability of the presented methodology. A great advantage is the possibility of to apply this approach for identification of simultaneous damages.

Uso de indicadores hidrológicos para classificação de trechos de estradas florestais quanto ao escoamento superficial

Forest roads are frequently pointed as source of environmental problems related to erosion and they also influence harvest cost due to maintenance operations. Roads not well designed are sources of hydrological problems on catchments and the current attention to sustainability of forest exploration projects point out to the need of diagnostics tools for guiding the redesign of the road system. At this study, runoff hydrological indicators for forest road segments were assessed in order to identify critical points of erosion and water concentration on soils. A road network of a forest production area was divided into 252 road segments that were used as observations of four variables: mean terrain slope, main segment slope, LS factor and topographic index. The data analysis was based on descriptive statistics for outliers' identification, principal component analysis and for variability study between variables and between observations, and cluster analysis for similar segments groups' identification. The results allowed classifying roads segments into five mains road types: road on the ridge, on the valley, on the slopes, on the slopes but in a contour line and on the steepest slope. The indicators were able to highlight the most critical segments that differ of others and are potential sources of erosion and water accumulation problems on forest roads. The principal component analysis showed two main variability sources related to terrain topographic characteristics and also road design, showing that indicators represent well those elements. The methodology seems to be appropriated for identification of critical road segments that need to be redesigned and also for road network planning at new forest exploration projects.

Effects of dredging operations on sediment quality: contaminant mobilization in dredged sediments from the Port of Santos, SP, Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Impact of maintenance of Macrobrachium rosenbergii de Man, 1879 (Crustacea, Decapoda, Palaemonidae) broodstock on the water used in culture ponds

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Isolation and maintenance of symbiotic fungi of ants in the tribe Attini (Hymenoptera: Formicidae)

O isolamento e a manutenção de fungos basidiomicetos simbiontes de formigas da tribo Attini tem sido dificultado pela baixa velocidade de crescimento desses fungos, bem como pela presença de muitos microrganismos que vivem na superfície do material que as formigas mantêm no interior nos ninhos como substrato para o crescimento dos seus fungos simbiontes. No presente trabalho nós descrevemos um método que aumenta em mais de sete vezes a eficiência de isolamento desses fungos, quando comparada àquela obtida por procedimentos tradicionais. Ninhos subterrâneos de formigas atíneas dos gêneros Atta, Acromyrmex, Trachymyrmex e Mycetarotes foram localizados e deles foram coletadas amostras contendo fungos simbiontes e formigas, que foram transportadas para o laboratório, onde as formigas foram capazes de limpar a cultura do fungo e estimular o seu crescimento. em seguida, porções dos micélios foram assepticamente coletadas e transferidas para meio Yeast Nitrogen Base contendo glicose e cloranfenicol. Para facilitar a manutenção dos isolados em culturas de laboratório, diferentes nutrientes foram analisados para a elaboração de um meio de cultivo complexo, que possibilitou aumentar a velocidade de crescimento dos fungos e estocá-los por longos períodos. O método foi aplicado com sucesso para os fungos simbiontes de todos os gêneros de formigas estudados, gerando, assim, um procedimento extremamente útil para a formação e manutenção de uma coleção representativa de diferentes fungos simbiontes de formigas da tribo Attini.

Protein Intake during Weight Loss Influences the Energy Required for Weight Loss and Maintenance in Cats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A survey for maintenance of virulent newcastle disease virus-free area in poultry production in Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Macromineral requirements for the maintenance and growth of Boer crossbred kids

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Prediction equations to estimate the demand of energy and crude protein for maintenance, gain and egg production for laying Japanese quails

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Energy balance for biodiesel production by the castor bean crop (Ricinus communis L.)

The castor bean crop (Ricinus communis L.) has acquired prestige due to industries interest in the oil quality and recently for new sources of energy demand. The experiment that served as basis for the data used in this study was conducted at the Lageado Experimental Farm, in Botucatu - SP, 2008. This study aimed to avaluate the crop viability through energy balance and energy efficiency since the implantation until biodiesel production using parameters of consumption in operational management for installation and maintenance of culture harvest and oil production. The soil management operations, sow and harvest consumed the total of 266.20 MJ ha(-1), gathering with the fertilizers, pesticides, fuels, lubricants, labor, seed and industrial processing totaled 56,808 MJ ha(-1) of energy inputs. The energy production was 72,814.00 MJ ha(-1). The industry still lacks studies thal would contribution data collection and more specific energy coefficients. The castor beans cultivation was considered efficient allowing again of 15983.44 MJ ha(-1) equivalent to about 415 liters of diesel oil.

Modeling and analysis of artificial neural networks applied in operations research

Artificial neural networks are dynamic systems consisting of highly interconnected and parallel nonlinear processing elements. Systems based on artificial neural networks have high computational rates due to the use of a massive number of these computational elements. Neural networks with feedback connections provide a computing model capable of solving a rich class of optimization problems. In this paper, a modified Hopfield network is developed for solving problems related to operations research. The internal parameters of the network are obtained using the valid-subspace technique. Simulated examples are presented as an illustration of the proposed approach. Copyright (C) 2000 IFAC.

The minimization of open stacks problem: A review of some properties and their use in pre-processing operations

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

The effect of salinization in maintenance of intermittent catheter

O uso de cateter intermitente representa um procedimento muito utilizado em ambiente hospitalar. Este estudo, de natureza experimental, teve como propósito a análise comparativa entre o cateter intermitente, preenchido com solução de heparina 100 U/ml e o preenchido com soro fisiológico 0,9%. Foi realizado um estudo comparativo, avaliando a formação de coágulos e se estes estivessem presentes seriam quantificados. Para tanto, foram utilizados quatro grupos de 7 coelhos, da linhagem Norfolk, sendo realizado acesso venoso em veia auricular conectado ao dispositivo de infusão múltipla. em dois destes grupos, foi usada solução salina; em um grupo, caso fosse encontrada resistência, esta seria forçada; no outro, esta resistência não seria forçada. Nos dois outros grupos, foi usada solução de heparina; em um grupo, caso fosse encontrada resistência, esta seria forçada; no outro esta resistência não seria forçada. O cateter intermitente foi mantido por 72 horas e, a cada 12 horas foi infundida água destilada, simulando a administração de medicamento. Durante o experimento foram observadas as seguintes variáveis: presença da formação de coágulos, comprimento do coágulo, peso fresco do coágulo, peso seco do coágulo, contagem plaquetária e desconforto. Na análise estatística feita pelo método não paramétrico Kruskal-Wallis, com nível de significância de sigma = 5%, não foi encontrada diferença significativa entre os grupos e momentos. Pôde-se constatar a presença de formação de coágulo em todos os grupos independentemente da solução de preenchimento. Concluímos, principalmente, que há necessidade de elaboração de novas normas e rotinas na utilização de cateter intermitente.

Associations among milk production and rectal temperature on pregnancy maintenance in lactating recipient dairy cows

The objective of this study was to evaluate the associations among milk production, rectal temperature, and pregnancy maintenance in lactating recipient dairy cows. Data were collected during an 11-mo period from 463 Holstein cows (203 primiparous and 260 multiparous) assigned to a fixed-time embryo transfer (ET) protocol. Only cows detected with a visible corpus luteum immediately prior to ET were used. Rectal temperatures were collected from all cows on the same day of ET. Milk production at ET was calculated by averaging individual daily milk production during the 7 d preceding ET. Pregnancy diagnosis was performed by transrectal ultrasonography 21 d after ET. Cows were ranked and assigned to groups according to median milk production (median = 35 kg/d; HPROD = above median; LPROD = below median) and rectal temperature (<= 39.0 degrees C = LTEMP; >39.0 degrees C = HTEMP). A milk production x temperature group interaction was detected (P = 0.04) for pregnancy analysis because HTEMP cows ranked as LPROD were 3.1 time more likely to maintain pregnancy compared with HTEMP cows ranked as HPROD (P = 0.03). Milk production did not affect (P = 0.55) odds of pregnancy maintenance within LTEMP cows, however, and no differences in odds of pregnancy maintenance were detected between HTEMP and LTEMP within milk production groups (P > 0.11). Within HTEMP cows, increased milk production decreased the probability of pregnancy maintenance linearly, whereas within LTEMP cows, increased milk production increased the probability of pregnancy maintenance linearly. Within HPROD, increased rectal temperature decreased the probability of pregnancy maintenance linearly, whereas within LPROD cows, no associations between rectal temperatures and probability of cows to maintain pregnancy were detected. In summary, high-producing dairy cows with rectal temperatures below 39.0 degrees C did not experience reduced pregnancy maintenance to ET compared to cohorts with reduced milk production. (C) 2011 Elsevier B.V. All rights reserved.