Condutividade e difusividade térmica do figo (Ficus carica L.) Roxo de Valinhos

The post harvest cooling and/or freezing processes for horticultural products have been carried out with the objective of removing the heat from these products, allowing them a bigger period of conservation. Therefore, the knowledge of the physical properties that involve heat transference in the fig fruit Roxo de Valinhos is useful for calculating projects and systems of food engineering in general, as well as, for using in equations of thermodynamic mathematical models. The values of conductivity and thermal diffusivity of the whole fig fruit-rami index were determined, and from these values it was determined the value of the specific heat. For these determination it was used the transient method of the Line Heat Source. The results shown that the fig fruit has a thermal conductivity of 0.52 W m-1°C, thermal diffusivity of 1.56 x 10-7 m² s-1, pulp density of 815.6 kg m-3 and specific heat of 4.07 kJ kg-1 °C.

Avaliação de danos mecânicos causados em banana Nanicão durante as etapas de beneficiamento, transporte e embalagem

This study had as objective the evaluation of mechanical damages occurred in banana Nanicão during the improvement process, packing and distribution, identifying the probable critical points. The mechanical damages caused by transport, first cleaning; cleanness and sorting; preservation in the packing, transport, and mature were evaluated. The studied packing had been: torito wooden packing (18 kg), wood type ½ box, (13 kg) and cardboard (18 kg). The stage of preservation and transport of the fruits to the distribution center duplicated the light defects and quintupled the serious defects, causing rottenness after the acclimatization. The cardboard packing did not support the piling up and presented deformations, that resulted in the kneading the fruits of the inferior packing, causing a significant increase of the serious defects. The fruits conditioned in the involved packing of plastic bubble had presented an inferior number of serious damages when compared with the others packing, without the plastic.

Índice de previsão de produção de leite para vacas Jersey

In Brazil the adoption of several models of cattle confinement leads to special conditions for management methods in dairy production, which can be improved by the use of technology that assures better herd management. Indexes relating environmental variables to production are applied for the prediction of milk production. The values of temperature and relative humidity, rain index, solar radiation and pasture soil temperature are generally considered potential stress agents for cows. The objective of this research was to develop an index for predicting milk production for high productivity Jersey milking cows lodged in semi confinement in tropical conditions. The experiment considered two treatments: A - the cows waited for 30 minutes prior to milking in a room with a shower associated to a fan; B - the cows did not have access to this room (control). Other than the waiting period, the cows had access to pasture. Differences in the effect of average production were not statistically significant. The analysis for studying the effect of the variables and designing the model led to a statistical model relating the variables milk production and rain index, as well as the maximum soil temperature of pasture, and milk production.

Análise do investimento em climatização para bovinos de leite em sistema de alojamento free-stall

The difficulty in adapting European dairy cows breeds in Brazil affect considerably the milk production sector. Brazilian climatic conditions are not totally favorable and the development of new tecnologies is needed for the animals express their genetic potential, as well as their best feed conversion. An economical analysis of the applied investment in the free-stall climatization equipment in dairy housing, for estimating studies related to profit, possibility of return investment as well as time for this return is necessary. The objective of this research was to evaluate the influence of climatization investment in the milk production process and analyze the economical aspect of this investment. There were used 470 high productive dairy cows with genetic and morphologic homogeneous characteristics, and analyzed in two similar periods. Investment calculations were done using Excell®. The results were satisfactory and the invested capital was proved to return to the producer in a short term, 57 days.

Classificação e padronização dos tomates cv. Carmem e Débora dentro da CEAGESP - SP

The creation of the Brazilian Program for the Modernization of the Horticulture by the Secretariat of Agriculture and Supplying of the State of São Paulo at CEAGESP, determined the standardization of fruit and vegetables in the follow aspects: degree of coloration, format, calibers, defects and packing. Therefore, the main goal of this research is to correlate the classification given by the Brazilian Program with the one used by the wholesalers at CEAGESP, verifying if the established norms are being fulfilled for cultivar Carmen and Debora (SAKATA SEED). The results showed, that for cultivar Carmem, for the averages of the observed values it does not move away from the norms created by the Program for sizes small and medium. However, for the case of cultivar Debora, the results showed differences between the adopted classifications. The tomatoes were devaluated, because had been commercialized below of the standardization indicated for the Brazilian Program.

Identificação eletrônica para avaliação do comportamento dos suínos na fase de gestação

The efficiency of swine production performance depends on the herd administration, such as good nutrition, sanitary control, facilities and appropriate environmental conditions. The concept of this production model is directly related with the reduction of selective losses and the process control. Each production segment is controlled to reach the optimization in the system totality, it is necessary to apply animals handling concepts, environmental control implementation, diseases control, nutrition control, information concerning in guaranteeing the animal welfare and individual identification. The present work presents as objective the development of the mathematical model to evaluate interactions among the internal atmosphere of the installation and the thermal animals preference, in the expectation of detecting a relationship among the frequency access to the drinking fountain and the atmosphere conditions - temperature, black globe temperature and relative humidity, using as tool the electronic identification. The results obtained by the mathematical model, allowed to conclude accurately the evaluation of the swine thermal preference correlating with the climatic variables in the pregnancy stage.

Modelo dinâmico de simulação e otimização da força normal de reação do solo para um mecanismo de corte basal

The physical model was based on the method of Newton-Euler. The model was developed by using the scientific computer program Mathematica®. Several simulations where tried varying the progress speeds (0.69; 1.12; 1.48; 1.82 and 2.12 m s-1); soil profiles (sinoidal, ascending and descending ramp) and height of the profile (0.025 and 0.05 m) to obtain the normal force of soil reaction. After the initial simulations, the mechanism was optimized using the scientific computer program Matlab® having as criterion (function-objective) the minimization of the normal force of reaction of the profile (FN). The project variables were the lengths of the bars (L1y, L2, l3 and L4), height of the operation (L7), the initial length of the spring (Lmo) and the elastic constant of the spring (k t). The lack of robustness of the mechanism in relation to the variable height of the operation was outlined by using a spring with low rigidity and large length. The results demonstrated that the mechanism optimized showed better flotation performance in relation to the initial mechanism.

Avaliação de tipos de ventilação em maternidade de suínos

Livestock facilities, where animals carry their productive cycle, must have as main characteristic, the control of influence over climatic factors on animals. The environment variations can be controlled through the use of different ventilation systems. The objective of this research was to evaluate the influence of different environment conditioning systems on swine nursery. Three treatments have been tested: natural ventilation, cooled ventilation and forced ventilation. The climatic parameters evaluated were: air temperature, relative humidity and black globe temperature. The physiological parameters analyzed were: respiratory frequency and back fat thickness. Number of born alive piglets, average weight at weaning and number of weaned piglets were also evaluated parameters. The use of cooled ventilation systems were able to decreased animal's air temperature and respiratory frequency, and the black globe temperature and humidity index (WBGT) and the radiating thermal load (RTL).

Desempenho físico-mecânico de minipainéis de terra crua tratada com aditivos químicos

The aim of this research was to study the effect of chemical additives (lime and Portland cement) associated with sodium silicate on soil in order to obtain compressed soil bricks. Mini panels were constructed with such bricks being their physical and mechanical characteristics determined in laboratory conditions and their behavior evaluated through the association of destructive and non-destructive methods. For this purpose a sandy soil and a finely divided one were added to Portland cement and lime in the dosage of 6% and 10% taken in dry weight basis in relation to the dry soil. The sodium silicate dosage of 4% was also taken in dry weight basis in relation to the dry soil-cement or to the dry soil-lime. The compressed soil bricks were cured in a humidity chamber for 7; 28; 56 and 91 days. The bricks were laid on the fourteenth day to form prismatic mini panels each one with four layers of bricks. After 28; 56 and 91 days the mini panels were submitted to both; ultrasonic and compressive tests to determine its elastic properties (dynamic modulus) and the compressive resistance. The best results in terms of compressive strength, water absorption capacity or dynamic elastic modulus, were reached by the sandy soil added to 10% of Portland cement or lime associated with sodium silicate.

Efeitos da cobertura do solo com filme de polietileno azul no consumo de água da cultura da alface cultivada em estufa

The covering of the soil is an agricultural practice that intends to control the harmful herbs, to reduce the losses of water by evaporation of the soil, and to facilitate the harvest and the commercialization, once the product is cleaner and healthier. However, when the soil is covered important microclimatic parameters are also altered, and consequently the germination of seeds, the growth of roots, the absorption of water and nutrients, the metabolic activity of the plants and the carbohydrates storage. The current trial intended to evaluate the effect of soil covering with blue colored film on consumptive water-use in a lettuce crop (Lactuca sativa, L.). The experiment was carried out in a plastic greenhouse in Araras - São Paulo State, Brazil from March 3rd, 2001 to May 5th, 2001. The consumptive water-use was measured through two weighing lysimeter installed inside the greenhouse. Crop spacing was 0.25 m x 0.25 m and the color of the film above soil was blue. Leaf area index (IAF), was measured six times (7; 14; 21; 28; 35; 40 days after transplant) and the water-use efficiency (EU) was measured at the end. The experimental design was subdivided portions with two treatments, bare soil and covered soil. The average consumptive water-use was 4.17 mm day-1 to the bare soil treatment and 3.11 mm day-1 to the covered soil treatment. The final leaf area index was 25.23 to the bare soil treatment and 24.39 to the covered soil treatment, and there was no statistical difference between then.

Projeto de um cortador de base para colhedora de cana-de-açúcar utilizando otimização matemática

A base-cutter represented for a mechanism of four bars, was developed using the Autocad program. The normal force of reaction of the profile in the contact point was determined through the dynamic analysis. The equations of dynamic balance were based on the laws of Newton-Euler. The linkage was subject to an optimization technique that considered the peak value of soil reaction force as the objective function to be minimized while the link lengths and the spring constant varied through a specified range. The Algorithm of Sequential Quadratic Programming-SQP was implemented of the program computational Matlab. Results were very encouraging; the maximum value of the normal reaction force was reduced from 4,250.33 to 237.13 N, making the floating process much less disturbing to the soil and the sugarcane rate. Later, others variables had been incorporated the mechanism optimized and new otimization process was implemented .

Simulação da varredura da superfície por um cortador de base segmentado

Base cutting and feeding into harvesters of plants lying close to the ground surface require an efficient sweeping action of the cutting mechanism. It is not the case of conventional sugarcane harvesters which have rigid blades mounted on discs capable to contaminate the cane with dirt as well as damage the ratoons. The objective of this work was to simulate the sweeping performance of a segmented base cutter. The model was developed using the laws of dynamic. Simulation included two rotational speeds (400 and 600 rpm), two cutting heights (0.12 and 0.13 m) and two disk tilting angles (-10º and -12º). The simulated sweeping angle varied between 56º and 193º, which are very promising as a mean to cutting and feeding cane sticks lying on the ground. Cutting height was the variable that affected sweeping action the most. This behavior indicates the need to have an automatic control of the cutting disk height in order to keep good sweeping performance as the harvester moves forward.

Avaliação do uso de identificadores eletrônicos em suínos

Nowadays the consumer market demands a gradually increase in the products' quality control. The manual control that exits, used in animal production, shows ineficiency in warrating an increasing percentual of the desirable quality, so this can only be reached when an effective animal tracebility system is applied, from birth to slaughter. Individual electronic identification presents high importance in this focus, providing information recorded directly from the animal. Electronic traceability uses electronic devices that emit a signal activated by a fixed reader placed where it is needed to record a certain event, or uses a manual reader which allows a higher independence of the operator. Knowing the importance of the electronic identification as a tool for applying traceability in animal production, this research had as objective to evaluate the use of transponders in order to garantee the manual reading as well as the fixed antenna reading. The following implant places were analized in piglet, just after their birth: 1) forehead, 2) external ear lobule, 3) the posterior auricular base, and 4) a transponder inserted in a earing implanted in the ear lobule. The factors of skin damage and migration were analized, as well as the reading efficiency. It was found that the best implant place was the posterior ear base.

Desenvolvimento e avaliação de uma servoválvula de baixo custo para a aplicação de insumos líquidos

The present work aimed the development of a low cost servo-valve that answers to an electronic control signal, for variable rates liquid inputs application. A literature research to define which valve type should be used was made. A mechanically activated proportional valve with an electronically controlled servo-engine was designed and evaluated. Since developed the servo-valve, the system was submited to a number of tests .The evaluation of its behavior was obtained in terms of repeatability, hystheresis and linearity. The test was accomplished in a bench, specially developed for this aim. As a result, were obtained three curves of opening percentage as function of flow rate, describing three opening and closing increments in two different work pressures. The servo-valve presented a good repeatability, reasonable hysteresis and a typically quadratic curve. This one maintained the low cost target. These results were very satisfied because the non-linearity and the hysteresis could be easily corrected by software.

Rigidez do papelão ondulado: comparação entre resultados experimentais e os obtidos por cálculo analítico

Cardboard packing for horticultural products has as main function to protect them. The design of a cardboard packing request the knowledge of the bending stiffens which is depending on the modulus of elasticity. The objective of this work was to calculate the cardboard modulus of elasticity from data obtained in laboratory using physical characterization test, with different methods, and comparing the results with the values obtained experimentally. Ten samples of each cardboard selected for this study were tested in the paper fabrication direction and in its transverse direction. The papers liner and medium resistance to the traction, used to calculate the bending stiffness, was determined in a universal machine test. To obtaining of the bending stiffens the four points test was accomplished. Expressive variations among the methods from which the modulus of elasticity is obtained were observed and that influence the bending stiffness of the structure. The stiffness values obtained experimentally were always greater than the values obtained from analytical method. This difference can be attributed to two factors, the production processes that assurance a larger rigidity than the components separately and the addition of the adhesive layer that is not taken in consideration in the analytic calculations.