An image processing method for morphology characterization and pitting corrosion evaluation

A digital image processing and analysis method has been developed to classify shape and evaluate size and morphology parameters of corrosion pits. This method seems to be effective to analyze surfaces with low or high degree of pitting formation. Theoretical geometry data have been compared against experimental data obtained for titanium and aluminum alloys subjected to different corrosion tests. (C) 2002 Elsevier B.V. B.V. All rights reserved.

Histochemical and SEM evaluation of the neuromuscular junctions from alcoholic rats

In the present study morphological changes occurring in the neuromuscular junctions (NMJ) of the extensor digitorum longus (EDL) and soleus muscles from albino rats (Rattus norvegicus) submitted to experimental chronic alcoholism were evaluated. Seventy two male animals aged 4 months and weighing on average 400 g were divided into three groups: control, alcoholic and isocaloric. Six rats from each group were anesthetized and sacrificed after 5, 10, 15 and 18 months. The NMJ did not show detectable morphological changes in either muscle after treatment when examined by light microscopy. With respect to the dimensions, statistical analysis demonstrated a tendency to a statistically significant treatment x time interaction for the length of soleus muscle NMJ. The ultrastructural study, however, revealed that the NMJ of the soleus muscle of animals submitted to 18 months of experimental alcoholism presented important morphological alterations. Characteristically, the NMJ of these muscles is located on an elevation on the surface of the muscle fiber, presenting a regular round, oval or elliptical shape and continuous and not very deep synaptic grooves. Approximately 30% of the NMJ of alcoholic rats are irregular in shape, with the sarcolemmal elevations typical of the synapse region being flattened on at least one side, with discontinuous synaptic grooves, and deep and punctiform contacts of the synaptic buds. These data suggest that, although skeletal muscle has a greater natural resistance against the direct or indirect effects of alcohol, some submicroscopic morphological alterations are detectable in the NMJ, especially in muscles with oxidative metabolism (soleus) following long periods of ingestion of alcohol. (C) 2002 Elsevier B.V. Ltd. All rights reserved.

Photoluminescence in amorphous (PbLa)TiO3 thin films deposited on different substrates

Pb1-XLaXTiO3 thin films, (X = 0.0; 13 and 0.27 mol%) were prepared by the polymeric precursor method. Thin films were deposited on Pt/Ti/SiO2/Si (1 1 1), Si (1 0 0) and glass substrates by spin coating, and annealed in the 200-300degreesC range in an O-2 atmosphere. X-ray diffraction, scanning electron microscopy and atomic force microscopy were used for the microstructural characterization of the thin films. Photoluminescence (PL) at room temperature has been observed in thin films of (PbLa)TiO3. The films deposited on Pt/Ti/SiO2/Si substrates present PL intensity greater than those deposited on glass and silicon substrates. The intensity of PL in these thin films was found to be dependent on the thermal treatment and lanthanum molar concentration. (C) 2002 Elsevier B.V. B.V. All rights reserved.

Progesterone upregulates GATA-1 on erythroid progenitors cells in liquid culture

Steroids hormones modify the hematological features of homozygous sickle cell disease, including the levels of fetal hemoglobin. We used semi-quantitative RT-PCR analysis of GATA-1, GATA-2, NF-E2, and gamma-globin mRNA levels in a two-phase liquid culture system of human adult erythroid cells in order to assay the effect of progesterone upon gene expression. The levels of expression of GATA-1 and gamma-globin mRNA were significantly increased in cells treated with progesterone compared to untreated cells (1.7- to 2.0-fold). Progesterone treatment did not produce any stimulatory effect upon GATA-2 and NF-E2 mRNA expression. Differences in the synthesis of HbF protein could not be detected by flow cytometry, although we observed a small difference in mean intensity fluorescence between cells treated and cells untreated with progesterone on days 7 and 9. Using anti-transferrin receptor and anti-glycophorin A antibodies, we verified that addition of progesterone did not cause any change in erythroid proliferation and differentiation. In conclusion, it is possible that the increased expression of gamma-globin mRNA after progesterone treatment observed in this study may be related to the increased GATA-1 mRNA expression. Interactions of the steroid receptors with the basal transcriptional machinery and with transcription factors might mediate their transcriptional effects. (C) 2002 Elsevier B.V. (USA).

Optimization of Radial Basis Function neural network employed for prediction of surface roughness in hard turning process using Taguchi's orthogonal arrays

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Embryo recovery and pregnancy rates after the delay of ovulation and fixed time insemination in superstimulated beef cows

The aim of this study was to evaluate the effect of delaying ovulation subsequent to superstimulation of follicular growth in beef cows (Bos indicus) on embryo recovery rates and the capacity of embryos to establish pregnancies. Ovulation was delayed by three treatments using either progesterone (CIDR-B®) or a GnRH agonist (deslorelin). Multiparous Nelore cows (n = 24) received three of four superstimulation treatments in an incomplete block design (n = 18 per group). Cows in Groups CTRL, P48 and P60 were treated with a CIDR-B device plus estradiol benzoate (EB, 4 mg, i.m.) on Day-5, while cows in Group D60 were implanted with deslorelin on Day-7. Cows were superstimulated with FSH (Folltropin-V® 200 mg), from Day 0 to 3, using twice daily injections in decreasing amounts. All cows were treated with a luteolytic dose of prostaglandin on Day 2 (08:00 h). CIDR-B devices were removed as follows: Group CTRL, Day 2 (20:00 h); Group P48, Day 4 (08:00 h); Group P60, Day 4 (20:00 h). Cows in Group CTRL were inseminated at 10, 20 and 30 h after first detected estrus. Ovulation was induced for cows in Group P48 (Day 4, 08:00 h) and Groups P60 and D60 (Day 4, 20:00 h) by injection of LH (Lutropin®, 25 mg, i.m.), and these cows were inseminated 10 and 20 h after treatment with LH. Embryos were recovered on Days 11 or 12, graded and transferred to synchronized recipients. Pregnancies were determined by ultrasonography around Day 100. Data were analyzed by mixed procedure, Kruskal-Wallis and Chi-square tests. The number of ova/embryos, transferable embryos (mean ± S.E.M.) and pregnancy rates (%) were as follows, respectively: Group CTRL (10.8 ± 1.8, 6.1 ± 1.3, 51.5), P48 (12.6 ± 1.9, 7.1 ± 1.0, 52.3), P60 (10.5 ± 1.6, 5.7 ± 1.3, 40.0) and D60 (10.3 ± 1.7, 5.0 ± 1.2, 50.0). There were no significant differences among the groups (P > 0.05). It was concluded that fixed time AI in association with induced ovulation did not influence embryo recovery. Furthermore, pregnancy rates in embryos recovered from cows with delayed ovulation were similar to those in embryos obtained from cows treated with a conventional superstimulation protocol. © 2002 Elsevier B.V. All rights reserved.

Food restriction-induced myocardial dysfunction demonstrated by the combination of in vivo and in vitro studies

The aim of this study was to test the hypothesis that protein-calorie undernutrition decreases myocardial contractility jeopardizing ventricular function, and that ventricular dysfunction can be detected noninvasively. Five-month-old male Wistar-Kyoto rats were fed with regular rat chow ad libitum for 90 days (Control group, n = 14). A second group of rats received 50% of the amount of diet consumed by de control group (Food restricted group, n = 14). Global LV systolic function was evaluated in vivo, noninvasively, by transthoracic echocardiogram. After echocardiographic study, myocardial contractility was assessed in vitro in the isovolumetrically beating isolated heart in eight animals from each group (Langendorff preparation). The in vivo LV fractional shortening showed that food restriction depressed LV systolic function (p < 0.05). Myocardial contractility was impaired as assessed by the maximal rate of rise of LV pressure (+dP/dt), and developed pressure at diastolic pressure of 25 mmHg (p < 0.05). Furthermore, food restriction induced eccentric ventricular remodeling, and reduced myocardial elasticity and LV compliance (p < 0.05). In conclusion, food restriction causes systolic dysfunction probably due to myocardial contractility impairment and reduction of myocardial elasticity. © 2002 Elsevier B.V. All rights reserved.

Neonatal inhalatory anesthetic exposure: Reproductive changes in male rats

We investigated the effects of an inhalatory anesthetic (ethyl ether) during the neonatal period of brain sexual differentiation on the later fertility and sexual behavior of male rats. Animals were exposed to ethyl ether immediately after birth. At adulthood, body weight, testes wet weight, and plasma testosterone levels were not affected; however, neonatal exposure to ether showed alterations on male fertility: a decrease in the number of spermatids and spermatozoa, an increase in the transit time of cauda epididymal spermatozoa and a decrease in daily sperm production. An alteration of sexual behavior was also observed: decreased male sexual behavior and appearance of homosexual behavior when the male rats were castrated and pretreated with exogenous estrogen. Probably, the ether delayed or reduced the testosterone peak of the sexual differentiation period, altering the processes of masculinization and defeminization of the hypothalamus. Our results indicate that perinatal exposure to ethyl ether during the critical period of male brain sexual differentiation, acting as endocrine disruptors, has a long-term effect on the fertility and sexual behavior of male rats, suggesting endocrine disruption through incomplete masculinization and defeminization of the central nervous system. © 2002 Elsevier B.V. All rights reserved.

Simulation of the flow through automatic valves of hermetic compressors by the immersed boundary method approach

The main goal of the present work is to verify the applicability of the Immersed Boundary Method together with the Virtual Physical Model to solve the flow through automatic valves of hermetic compressors. The valve was simplified to a two-dimensional radial diffuser, with diameter ratio of D/d = 1.5, and simulated for a one cycle of opening and closing process with a imposed velocity of 3.0 cm/s for the reed, dimensionless gap between disks in the range of 0.07 < s/d < 0.10, and inlet Reynolds number equal to 1500. The good results obtained showed that the methodology has great potential as project tool for this type of valve systems. © The Authors, 2011.

Experimental research on the influence of the air humidity conditions in an air conditioning system

The factors that have influence on the energy consumption of a small air conditioning system that are worth mentioning are the efficiencies of the compressor, evaporator and condenser, the form that the refrigerant flow is controlled, the fan model used, and climatic conditions. Within the climate issue, an interesting factor is that the relative humidity when it comes to the effect that it causes, especially in the performance of the air condenser, which generally is not considered in the projects. This study aims to evaluate the influence of humidity on the coefficient of system performance (COP), seeking to quantify their influence when it happens. The tests were performed on a testing bench, mounted at the Laboratory for Energy Efficiency (LAMOTRIZ) UNESP-Campus Guaratinguetá. In the study, the wet bulb temperature was ranged, keeping the rotation of the scroll compressor with application of a frequency inverter in its best performance. The test bench is provided with a supervisory system of data collection that is also able to control all functions of the bench. In the results, there was a significant influence, particularly when comparing high humidity conditions with low humidity, noting that only over 65% relative humidity is that significant changes are observed in the COP of the system. © 2013 Elsevier Inc.

Perdas na colheita e qualidade da fibra de cultivares de algodão adensado em função de sistemas de colheita

Pós-graduação em Agronomia (Energia na Agricultura) - FCA

An assessment of the economic impact of climate change on the tourism sector in Montserrat

This report provides an analysis and evaluation of the likely effects of climate change on the tourism sector in Montserrat. Clayton (2009) identifies three reasons why the Caribbean should be concerned about the potential effects of climate change on tourism: (a) the relatively high dependence on tourism as a source of foreign exchange and employment; (b) the intrinsic vulnerability of small islands and their infrastructure (e.g. hotels and resorts) to sea level rise and extreme climatic events (e.g. hurricanes and floods); and, (c) the high dependence of the regional tourist industry on carbon-based fuels (both to bring tourist to the region as well as to provide support services in the region). The effects of climate change are already being felt on the island. Between 1970 and 2009, there was a rise in the number of relatively hot days experienced on the island. Added to this, there was also a decline in mean precipitation over the period. Besides temperature, there is also the threat of wind speeds. Since the early 20th century, the number of hurricanes passing through the Caribbean has risen from about 5-6 per year to more than 25 in some years of the twenty-first century. In Montserrat, the estimated damage from four windstorms (including hurricanes) affecting the island was US$260 million or almost five times 2009 gross domestic product (GDP). Climate change is also likely to significantly affect coral reefs. Hoegh-Guldberg (2007) estimates that should current concentrations of carbon dioxide in the Earth’s atmosphere rise from 380ppm to 560ppm, decreases in coral calcification and growth by 40% are likely. The report attempted to quantify the likely effects of the changes in the climatic factors mentioned above. As it relates to temperature and other climatic variables, a tourism climatic index that captures the elements of climate that impact on a destination’s experience was constructed. The index was calculated using historical observations as well as those under two likely climate scenarios: A2 and B2. The results suggest that under both scenarios, the island’s key tourism climatic features will likely decline and therefore negatively impact on the destination experience of visitors. Including this tourism climatic index in a tourism demand model suggests that this would translate into losses of around 145% of GDP. As it relates to coral reefs, the value of the damage due to the loss of coral reefs was estimated at 7.6 times GDP, while the damage due to land loss for the tourism industry was 45% of GDP. The total cost of climate change for the tourism industry was therefore projected to be 9.6 times 2009 GDP over a 40-year horizon. Given the potential for significant damage to the industry, a large number of potential adaptation measures were considered. Out of these, a short-list of 9 potential options was selected using 10 evaluation criteria. These included: (a) Increasing recommended design wind speeds for new tourism-related structures; (b) Construction of water storage tanks; (c) Irrigation network that allows for the recycling of waste water; (d) Enhanced reef monitoring systems to provide early warning alerts of bleaching events; (e) Deployment of artificial reefs and fish-aggregating devices; (f) Developing national evacuation and rescue plans; (g) Introduction of alternative attractions; (h) Providing re-training for displaced tourism workers, and; (i) Revised policies related to financing national tourism offices to accommodate the new climatic realities Using cost-benefit analysis, three options were put forward as being financially viable and ready for immediate implementation: (a) Increase recommended design speeds for new tourism-related structures; (b) Enhance reef monitoring systems to provide early warning alerts of bleaching events, and; (c) Deploy artificial reefs or fish-aggregating devices. While these options had positive benefit cost ratios, other options were also recommended based on their non-tangible benefits: an irrigation network that allows for the recycling of waste water, development of national evacuation and rescue plans, providing retraining for displaced tourism workers and the revision of policies related to financing national tourism offices to accommodate the new climatic realities.

Aspectos ecológicos de Boophilus microplus (CANESTRINI, 1887) (ACARINA: IXODIDAE) no município de Franca, nordeste de São Paulo

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estratégias de controle de ordem fracionária aplicadas ao amortecimento de oscilações eletromecânicas em sistemas elétricos de potência

Neste trabalho é proposta uma nova metodologia de projeto de estabilizadores de sistemas de potência baseada em teoria de sistemas de ordem fracionária (ESP-OF). A estratégia é baseada em uma generalização do projeto de compensadores do tipo rede avançoatraso (lead-lag) para o domínio de funções de transferência de ordem fracionária. Uma nova variável de projeto, a qual define a ordem da dinâmica fracionária do controlador, é sintonizada para se obter um compromisso entre um bom desempenho no amortecimento do modo eletromecânico dominante e uma robustez ampliada do ESP-OF. O desempenho do ESP-OF foi avaliado experimentalmente, em um sistema de potência em escala reduzida, localizado no Laboratório de Sistemas de Potência da Universidade Federal do Pará. A referida planta de teste apresenta uma estrutura típica do tipo gerador síncrono conectado a um barramento infinito e exibe um modo dominante de oscilação eletromecânica, de amortecimento extremamente reduzido, cujo valor da frequência natural é em torno de 1,2 Hz. O ESP-OF foi então projetado para ampliar o amortecimento relativo desse modo alvo, para toda a faixa de operação admissível. Para fins de implementação prática, primeiramente foram realizados testes experimentais para a identificação de um modelo nominal da planta, sob a forma de uma função de transferência pulsada, para uso na fase de projeto. O modelo obtido experimentalmente foi então validado e posteriormente utilizado tanto para o projeto do ESP-OF quanto para o projeto de um ESP convencional (utilizado para fins de comparação de desempenho). As leis de controle amortecedor do ESP-OF foram calculadas, convertidas para a forma de equações a diferenças e, subsequentemente, embarcadas em sistema digital baseado em microcontrolador DSPIC. Diversos testes de resposta ao impulso foram realizadas sob diferentes condições operacionais. As respectivas respostas dinâmicas dos sinais de saída da planta (desvio de potencia ativa) e do esforço de controle foram registradas para fins de análise. Os resultados experimentais mostraram que o ESP fracionário apresentou um desemprenho dinâmico e robustez similar em comparação com o desempenho obtido por um ESP convencional, para toda a faixa de operação investigada.

Impacts of Reproductive Technologies on Beef Production in South America

The majority of beef cow herds in South America are constituted by Bos indicus females, which have particular reproductive features that contribute to reduced reproductive efficiency compared with that of B. taurus cohorts. Hence, several alternatives to enhance reproductive efficiency of B. indicus heifers and cows have been developed to address their inherent reproductive shortcomings. These research-based technologies are being described in detail within this chapter and have already made an impact on South American B. indicus-based production systems. These include the following: (a) hormonal protocols to induce puberty in nulliparous heifers or estrous cyclicity in postpartum cows to maximize their reproductive performance during the subsequent breeding season, (b) hormonal protocols to synchronize estrus and/or ovulation in B. indicus females to exploit their reproductive responses to artificial insemination, and (c) genetic and environmental factors that influence reproductive success in beef herds, including reproductive diseases and excitable temperament of B. indicus females, that have been investigated to support/promote the development of appropriate mitigation technologies.