Pulsação de conjudado em motores monofásicos de capacitor permanente alimentados por tensões não senoidais

Pós-graduação em Engenharia Elétrica - FEB

INFLUENCE of THE EVAPORATOR POSITION IN STATIC DOMESTIC REFRIGERATORS

The temperature and velocity distributions of the air inside the cabinet of domestic refrigerators affect the quality of food products. If the consumer knows the location of warm and cold zones in the refrigerator, the products can be placed in the right zone. In addition, the knowledge of the thickness of thermal and hydrodynamic boundary layers near the evaporator and the other walls is also important. If the product is too close to the evaporator wall, freezing can occur, and if it is too close to warm walls, the products can be deteriorated. The aim of the present work is to develop a steady state computational fluid dynamics (CFD) model for domestic refrigerators working on natural convection regime. The Finite Volume Methodology is chosen as numerical procedure for discretizing the governing equations. The SIMPLE-Semi-Implicit Method for Pressure-Linked Equations algorithm applied to a staggered mesh was used for solving the pressure-velocity coupling problem. The Power-Law scheme is employed as interpolation function for the convective-diffusive terms, and the TDMA-Tri-Diagonal Matrix Algorithm is used to solve the systems of algebraic equations. The model is applied to a commercial static refrigerator, where the cabinet is considered an empty three-dimensional rectangular cavity with one drawer at the bottom of the cabinet, but without shelves. In order to analyze the velocity and temperature fields of the air flow inside the cabinet the evaporator temperature, Te, was varied from -20 degrees C to 0 degrees C, and nine different evaporator positions are evaluated for evaporator temperature of -15 degrees C. The cooling capacity of the evaporator for the steady state regime is also computed for each case. One can conclude that the vertical positioning of the evaporator inside the cabinet plays an important role on the temperature distribution inside the cabinet.

Structural features of the epididymal region of the domestic duck (Anas plathyrynchos)

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

In vitro Survival of Follicles Collected from Domestic Cats' Ovaries at Different Stages of Oestrous Cycle and Cultured with IGF-1

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Use of near-infrared Raman spectroscopy to detect IgG and IgM antibodies against Toxoplasma gondii in serum samples of domestic cats

Near-infrared Raman spectroscopy (NIRS) is a particularly promising technique that is being used in recent years for many biomedical applications. Optical spectroscopy has gained increasing prominence as a tool for quantitative analysis of biological samples, clinical diagnostic, concentration measurements of blood metabolites and therapeutic drugs, and analysis of the chemical composition of human tissues. Toxoplasmosis is an important zoonosis in public health, and domestic cats are the most important transmitters of the disease. This disease can be detected by several serological tests, which usually have a high cost and require a long time. The goal of this work was to investigate a new method to diagnosis Toxoplasma gondii infections using NIRS. In order to confirm antibody detection, 24 cat blood scrum samples were analyzed by the Raman spectra, from which 23 presented positive serology to toxoplasmosis and one was a reference negative serum. Characteristic Raman peaks allowed differentiation between negative and positive sera, confirming the possibility of antibody detection by Raman spectroscopy. These results give the first evidence that this technique can be useful to quantify antibodies in cat sera.

Postharvest Storage of 'Ponkan', 'Satsuma Okitusu' and 'Fremont' Tangerines and Their Minimally Processed Products Using Refrigeration and Controlled Atmosphere

This study aimed to evaluate the postharvest conservation of tangerines 'Fremont', 'Satsuma Okitsu' and 'Ponkan' when stored at different conditions, as well as the quality of the minimally processed product. Fruit were harvested when a sugar: acid ratio of 10.0 to 12.0 for 'S. Okitsu' and 'Fremont' and 16.0 to 19.0 for 'Ponkan' was reached, selected for uniformity of color, size, and absence of injuries. Whole fruits were stored at 3 degrees C, 85% RH and 7 degrees C, 95% RH, and after each storage period, fruits were brought to ambient conditions (22 degrees C, 65% RH) for 3 days before evaluation. The minimally processed products (peeled) were packed in polystyrene trays (22.4x14.8x3.7 cm) coated with polyvinyl chloride (PVC) stretchable, with 0.014 mm thickness, and in lidded packages (500 ml) of transparent polyethylene terephthalate. Fruit were analyzed for appearance, weight loss, respiratory rate, package atmosphere, rind and pulp color, soluble solids, titratable acidity and ascorbic acid content. Shelf life of tangerine 'Fremont' was limited to 42 days based on freshness. Its minimally processed product had a 9 day shelf-life for products packaged in PVC film. The mandarins 'S. Okitsu' had 35 days shelf-life at 7 degrees C, which was reduced to 28 days at 3 degrees C. Its fresh-cut product had a shelf-life of 15 days, stored in PVC or PET. 'Ponkan' fruit stored at 3 degrees C had a shelf life of 35 days, which was reduced to 28 days at 7 degrees C. When minimally processed, its shelf-life lasted for 15 days, whether packaged in PVC or PET. The 'Ponkan' had a shelf-life of 35 days at 3 degrees C and 28 days at 7 degrees C, also limited by loss of freshness. When minimally processed and stored in PVC or PET, its shelf life reached 15 days.

Genetic relatedness among wild, domestic and Brazilian fighting roosters

Except for the meat- and egg-type strains used in commercial poultry farms in Brazil, there are no scientific reports about the origin of birds from the genus Gallus that have been introduced in this country with domestication or fighting purposes. Therefore, the aim of this study was to identify the position of the Brazilian Game Bird in the phylogenetic tree of the genus Gallus by nucleotide sequence analysis of the mitochondrial DNA D-loop region. The results indicate that fighting roosters comprise two different clusters within the species Gallus gallus domesticus. One of the clusters is related to the wild ancestors, while the other one is more related to the birds raised by the poultry industry. In conclusion, Brazilian fighting roosters have originated from the red jungle fowl (Gallus gallus) and belong to the subspecies Gallus gallus domesticus.

Morphological, biological and molecular characterization of three strains of Trypanosoma cruzi Chagas, 1909 (Kinetoplastida, Trypanosomatidae) isolated from Triatoma sordida (Stal) 1859 (Hemiptera, Reduviidae) and a domestic cat

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Refrigerator COP with thermal storage

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

A novel HPF voltage source rectifier for variable speed refrigeration systems

A novel single-phase voltage source rectifier capable to achieve High-Power-Factor (HPF) for variable speed refrigeration system application, is proposed in this paper. The proposed system is composed by a single-phase high-power-factor boost rectifier, with two cells in interleave connection, operating in critical conduction mode, and employing a soft-switching technique, controlled by a Field Programmable Gate Array (FPGA), associated with a conventional three-phase IGBT bridge inverter (VSI - Voltage Source Inverter), controlled by a Digital Signal Processor (DSP). The soft-switching technique for the input stage is based on zero-current-switching (ZCS) cells. The rectifier's features include the reduction in the input current ripple, the reduction in the output voltage ripple, the use of low stress devices, low volume for the EMI input filter, high input power factor (PF), and low total harmonic distortion (THD) in the input current, in compliance with the EEC61000-3-2 standards. The digital controller for the output stage has been developed using a conventional voltage-frequency control (scalar V/f control), and a simplified stator oriented Vector control, in order to verify the feasibility and performance of the proposed digital controls for continuous temperature control applied at a refrigerator prototype.

Thermal treatment of superconductor thin film of the BSCCO system using domestic microwave oven

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

An overview of domestic aspects in US climate policy

The article shows how domestic aspects influence the United States national and international climate policy. To accomplish the task, the authors analyzes the discussions when Bill Clinton was ruling the country, a time during which global discussions were forwarded. The paper recalls the debate in the Bush administration and the growing polarization since Barack Obama took office.

The Impact of Domestic Politics and International Changes on the Brazilian Perception of Regional Integration

This article aims to analyze the impact of domestic politics and international changes that influence Brazilian positions regarding regional integration processes in South America, particularly the Southern Common Market, Mercosur. The dynamics of the international system and their impact on the evolution of the elite's perception of the role the country should play in the world are important variables for understanding these positions. The state's postures in relation to integration were and are based on a real interest, but this interest is also linked with the objective of ensuring better conditions for participation in other international arenas. Starting with the hypothesis that transformations in the international setting have strongly influenced Brazil's positioning, the elements of continuity and change in the country's behavior toward Mercosur are identified, with domestic politics as the main explanation.

Giving up reporting the aggressor: reports of female victims of domestic violence

The goal of this study is to describe the experience of female victims of domestic violence, who forfeited the lawsuits against their aggressors. The interviews were oriented by the question: What was your experience of forfeiting the denunciation of your aggressor? Three themes emerged from the convergence of the testimonies: time passed from the aggression to the denunciation and then to the forfeiting; the partner, the family, the women's precinct; reflecting about the experience, which described the studied phenomenon. The women expressed ambiguous feelings for their aggressor: affection, anger, humiliation and fear. They recognize that they are dominated and humiliated, but notions of justice and equality between spouses do not appear in the testimonies. Forfeiting can be understood in the context of the reproduction of the traditional family structure, conditioned to economic and social factors. Results highlight implications about the role of the Women's Precinct and the healthcare institutions in the care for women who were victims of domestic violence.

Occurrence of Leishmania (Leishmania) chagasi in a domestic cat (Felis catus) in Andradina, São Paulo, Brazil: case report

Neste trabalho, é relatada a infecção natural por Leishmania em um gato doméstico no qual, formas amastigotas do parasito foram observadas em imprint de linfonodo poplíteo. Reações sorológicas positivas e negativas foram observadas pelo teste de imunoadsorção enzimática (ELISA) e reação de imunofluorescência indireta (RIFI), respectivamente. A reação em cadeia da polimerase (PCR) revelou que a sequência de nucleotídeos foi idêntica à Leishmania (L.) chagasi. Este é o primeiro relato da doença em felino da cidade de Andradina, Estado de São Paulo, Brasil, área considerada endêmica para leishmaniose visceral canina e humana.