405 resultados para Eficiência mecânica


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This research was conducted to evaluate the productive performance (live weight gain and carcass weight gain and gain efficiency) of animals from four zebu breed slaughtered in three maturity stages. Thirty-six bulls from Gyr, Guzera, Mocho Tabapua and Nellore with twenty-four months of average age and average initial live weight of 357.6, 362.0, 368.6 and 376.4 kg, respectively, were used. The bulls, from each breed, were randomly assigned to individual pens and were full-fed a diet containing 50% concentrate (DM basis) and distributed to three category (1, 2 and 3) of slaughter weights. The bulls from category 1, 2 and 3 were slaughtered when reached the individual live weight of 405, 450 and 500 kg, respectively. At slaughter the empty body weight was determined. The Nellore breed bulls showed greater average empty body weight gain and carcass gain in relation to the other breeds, which did not differ among themselves. There were no differences among breeds regarding to feed efficiency (empty body weight gain efficiency and carcass gain efficiency per unit of metabolizable energy intake). The slaughter weight did not influence the empty body weight gain and carcass gain, but animals slaughtered at higher slaughter weights showed lower gain efficiency and spent more time in feedlot.

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The objective of this research was to test the control of Brevipalpus phoenicis (Geijskes, 1939) by the hexythiazox and quinometionato products in citrus crop with and without adhesive spread and when submitted to artificial rain. The plants were sprayed at 2, 4, 8, 24 and 48 hours. When dried, the fruits were collected (eight/plants) and half of them were washed in laboratory with artificial rainfall on the basis of 30 mm/h during 15 minutes establishing the following treatments: T1 - hexythiazox + washing; T2 - hexythiazox + agral + washing; T3 - quinometionato + washing; T4 - quinometionato + agral + washing; T5 - control + agral + washing; T6 - hexythiazox; T7 - hexythiazox + agral; T8 - quinometionato; T9 - quinometionato + agral; T10 - control + agral. Thus, all the fruits were inoculated with ten females of B. phoenicis and five days later the mites alive were counted and eliminated. Approximately 15 days later the number of larvae alive were also counted. The results obtained allowed the following conclusions: a) the acaricides were efficient to control B. phoenicis; b) the rainfall (washing) did not alter the efficiency; c) the agral did not change the results.

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To determine the effects of the pre-slaughter showering on some meat quality parameters, the biochemical changes in the Longus colli muscle and the bleeding efficiency were studied. Thirty-six Nelore steers were slaughtered in a commercial slaughterhouse. Eighteen animals were submitted to pre-slaughter showering; a control group of eighteen animals were slaughtered without showering. Samples were collected for evaluations in the muscle depth, in the anterior portion of longus colli muscle,just before chilling. Bleeding efficiency was evaluated through the ratio of muscle haemoglobin/blood haemoglobin using blood samples taken five seconds after bleeding, and muscle sample taken before chilling. Longus colli muscle samples were also used to determine glycogen, glucose, pH and acidity, 5, 24 and 48 hours after slaughtering. Multivariate methods were used to evaluate biochemical data and the bleeding efficiency data analysis followed the randomized block design. Haemoglobin retained in the muscle and bleeding efficiency were not affected (P > .05) by pre-slaughter showering. The pre-slaughter showering did not affect (P > .05) the glycolysis. There was a significant effect of time in glycogen, glucose, pH and acidity, in the first 24 hours.

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Vector potential of ants in mechanic dissemination of helminthes in a cat rescue center was analyzed in this study. Ants walking over cat's food and feces were collected and conditioned in distilled water. Cat feces were collected too. Ants were identified and the water where they were conditioned was observed on optic microscope. It was made the simple sedimentation technique to analyze feces. The results show that ants species Pheidole and Paratrechina can be potential vectors of nematode eggs, mainly Ascaridida, Toxocaridae.

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Inotropic effects of Propafenon were studied in isovolumic isolated guinea pig hearts submitted to infusion of the drug during 10 minutes. The dosages utilized caused: bradycardia, depression of AV nodal conduction and QRS widening. Simultaneously there was: decrease of the developed pressure (DP) and of the rate of rise of pressure (dp/dt), and elongation of the time of peak pressure. Since there was no clear relation between the heart rate and the inotropic indices (PD and dp/dt), it could be supposed that the depressor effect was not due to impairment of the chronotropism only. After the infusion of Propafenon, the chronotropic effect disapeared after 15 min, while the inotropic state presented a less satisfatory recuperation. The coronary output accompanied the myocardial metabolic needs, that is to say, there was a fall during the period of depressed cardiac function and a later tendency to increase during recovery.

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The objective of the present study was to investigate changes in colon wall in rats with fecal peritonitis (Per) associated with sodium diclofenac (SD) by studying breaking strength and tissue collagen concentration. The rats were divided into the following experimental groups: GROUP 1-SD: 60 animals injected intramuscularly with sodium diclofenac at the dose of 2 mg/kg body weight; GROUP 2-Per: 60 animals injected intraperitoneally with a suspension of human feces. Peritonitis was interrupted after six hours of evolution; GROUP 3-Per+SD: 60 animals injected intraperitoneally with a suspension of human feces and receiving SD according to the schedule used for Groups 1 and 2; CONTROL GROUP: 12 animals injected intramuscularly with physiological saline. The animals of Group 1, 2 and 3 were successively sacrificed 2, 4, 7, 14 and 21 days after interruption of peritonitis an/or the beginning of treatment. Under conditions of the experimental model and of the methods used, we conclude that sodium diclofenac, peritonitis and the peritonitis-sodium diclofenac association decrease the breaking strength and the concentration of tissue collagen in the colon segment.

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A greenhouse experiment was conducted in a factorial design of randomized complete blocks, with three replications, to study plantage response of soybean cultivars on efficiency: update (EAB); conversion (EC) and utilization, as well as utilization index (IU) by soybean cultivars. Four soybean cultivars (IAC 17, IAC 18, IAC 11 e FT 2) were grown in nutrient solutions with either adequate or deficient K levels (0.5 and 1.82 mmol. L-1) and harvested 20, 40 and 60 days after plant emergence (DAPE). The plants were separated in top, median and lower leaves, stems and roots, dried, ground and analyzed for K contents. Regardless of cultivar, in deficient plants K was translocated from the other organs to median leaves, in order to maintain its K contents. This behavior was particularly evident in 'IAC 11' and 'IAC 18'. Well nourished plants showed higher EAB than deficient plants. 'IAC 17' and 'IAC 18' showed higher EAB at either adequate or deficient K. levels. 'FT 2' showed highest EUK in deficient solutions at 40 DAPE (immediately before flowering), and the lowest EUK at 60 DAPE. The utilization index was helpful in determining cultivar plasticity to adapt to K deficiency. The highest plasticity was observed for 'FT 2' at 40 DAPE and for 'IAC 18' at 60 DAPE. K-deficient plants were more efficient in EC, yielding more dry matter for K uptake unit.

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Objective: the purpose of this study was to determine the effects of prone positioning on cardiorespiratory stability and weaning outcome of preterm infants during weaning from mechanical ventilation. Methods: from January to December 1999, a sample of 42 preterm infants, with birthweight < 2,000 g, mechanically ventilated in the first week of life, were randomly divided, in the beginning of the weaning process, in two groups according to the position: supine position (n = 21) or prone position (n = 21). Heart rate, respiratory rate, transcutaneous oxygen saturation and ventilatory parameters were recorded every one hour. Length of the weaning process and complications were also assessed. Results: in both groups the mean gestational age was 29 weeks, most of the patients presented very low birthweight and respiratory distress syndrome. The mean length of the weaning process was 2 days. There were no differences between the groups regarding respiratory rate, heart rate and transcutaneous oxygen saturation, however, oxygen desaturation episodes were more frequent in supine position (p = 0.009). Ventilatory parameters decreased faster and reintubation was less frequent in the prone group (4% versus 33%). No adverse effects of prone positioning were observed. Conclusion: these results suggest that prone position is a safe and beneficial procedure during the weaning from mechanical ventilation and may contribute to weaning success in preterm infants.

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The objective of the experiment was to test attractive substances for Africanized honey bees, Apis mellifera L., in avocado, Persea americana Mill. Were pulverized extracts of lemon grass (Cympobogon citratus), ocimum (Ocimum sellowii), Lippia alba, orange leaves (Citrus sinensis), eucaliptus leaves (Eucalyptus sp), eugenol and linalol and the frequency of bees on flowers were evaluated. The frequency of honey bees did increase with the application of the extracts falsa melissa, eucaliptus leaves and orange leaves, used as attractants in Quintal variety. The products tested in Eppendorf tubes did not increased the frequency the bees in Quintal and Fortuna varieties.

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Strongyloidiasis, a relatively common parasitism in tropical and sub-tropical areas, is the result of the infection by the smaller nematode, the Strongyloides stercoralis. Humans can be infected by this parasite, which has in its vital cycle free-life forms of male and female individuals able to live in the ground, and with another step necessary parasitism in the intestinal wall. The diagnostic of the infection is routinely done by the microscopic observation of the larva in stool samples and the high sensibility of urn method over another one allows an trustable and efficient diagnostic. The efficiency of three methods (Direct, COPROTEST and Rugai) used in the Parasitology Sector of the NAC-LACAL in Araraquara (SP) to diagnosis the strongiloidiasis were evaluated. A number of 2346 samples of stool of patients from NAC-LACAL and Nestor Goulart Reis Hospital were analyzed in the period between August and December of 2002. The Rugai Method with an positivity index of 65 % was elected as the most efficient of thee ones.

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The use of masks is generally accepted as a means of protecting the individual against microbial pathogens that might be inhaled in unhealthy environments. The objective of this study was to evaluate the efficiency of disposable surgical masks sold in Brazil, against coliforms in aerosols emitted by the aerators of a sanitary sewage treatment station. The filtration efficiency varied from 50.9% to 99.9% for 6 masks from different sources.

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A quite common problem in the recovery of degraded areas in the mineral exploration understands the compaction of the soil due to the intense traffic of machines and earth movement. The most common problem of the compaction of a degraded surface is: increase of the mechanical resistance to the penetration of the rooats, reduction of the aeration, alteration of the water flow and heat. Thus the present work had the basic objective of diagnosing the compaction of a degraded area by mining in a space way, through the mechanical resistance the way penetration to guide a future subsoiling in the place seeking recovery. Through the studies it was concluded that the kriging method in agreement with the space variation allows the division of the area studies in sub areas facilitating a future work to reduce cost and unnecessary interference to the atmosphere. The method was shown quite appropriate and it can be used in diagnosis of the compaction in a degraded area by mining, foreseeing subsoiling need.

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This paper evaluated the critical level, responsivity and boron use effciency on growth and the biomass production in six Eucalyptus grandis x Eucalyptus urophylla clones (Ca, Cb, Cc, Cd, Ce and Cf). An experiment was carried out in pots containing ground silicon, under greenhouse conditions using four boron rates per solution (0; 0.135; 0.27; 0.54 mg L -1 of B). The treatments were combined in a randomized block experimental design in a 4 × 6 factorial scheme with three replications. Plant height, stem diameter, dry matter production in the shoots of the plant and boron use effciency in the leaves, stem and total dry matter at the 8th month of age were evaluated. Due to boron fertilization, growth and shoot biomass were observed in the Eucalyptus plants after 240 days of being planted in pots. The increases in growth and biomass were 35 to 54% and 21 to 64%, respectively. The boron rates that promoted major growth of the plants were 0.33 to 0.44 mg L -1 of B and in this range the most effcient clone for dry matter production of leaves was Cf and the least effcient one to stem biomass production and the shoot biomass was Cd, no signifcant differences among other clones were observed. The critical level of boron in solution was 0.09 to 0.24 mg L -1 of B in the growth of the plants.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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The aim of this research was to identify the insects visiting flowers of sweet pepper and evaluate the effects of entomophilous pollination as a whole and, more especifically, of honeybees as pollinators of this crop. This study was carried out in the municipality of Taubaté, State of São Paulo, Brazil (21°01'S; 45°29'W; altitude: 570 m) from April to September, 2002. Insects were collected in thirty-six plants during 10 minutes/hour between 6:00 and 17:00h during days of maximum blooming. Twelve plots were subjected to the following treatments: (1) open-pollinated plots, freely visited by insects; (2) caged plots; (3) caged plots containing a hive of honeybees. Twelve species of insects visited the flowers. Exomalopsis spp. (Hymenoptera, Apidae) were the commonest ones (53,9% of visits). Fruits yielded in treatments (1) and (3) were heavier, presented higher diameter, thicker pericarp and more seeds per fruit than fruits in treatment (2). Results showed that fruits from insect pollinated plots presented better quality. Honeybeesas as pollinators were efficient as the other insects. sweet pepper, Capsicum annuum L., Solanaceae, pollination, Apis mellifera, honeybee.