956 resultados para Direct torque control


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In conservation agriculture, mainly under direct seeding, maintaining the vegetation ground cover is essential, since this serves as a reservoir of nutrients which are slowly released to plants by microorganisms. Some authors have sought to study increases in the amount of straw in the soil, in addition to slowing down the process of decomposition, with hormesis being one of the techniques used. This technique states that all chemical substances are both poisonous and nonpoisonous, with only the dosage determining whether they are lethal or not. This study aimed to evaluate the dry weight and agronomic characteristics of a crop of black oat subjected to hormesis. The experimental design was of randomised blocks, with 12 treatments and 4 replications, giving a total of 48 experimental lots. The treatments were: Haloxyfop-R Methyl Ester at dosages of 0.625, 1.25 and 2.50 g ha(-1); Glyphosate at dosages of 12.50, 25.00 and 50.00 g ha-1; 2,4-D dimethylamine salt at dosages of 100.00, 200.00 and 300.00 g ha(-1); Alterbane at a dosage of 500.00 g ha(-1); Salicylic acid at a dose of 100 g ha(-1); and a control. It was concluded that for the subdosages under test, the herbicides 2,4-D at medium dosage and Verdict at low dosage were shown to be the best treatments for conserving straw as ground cover under direct seeding.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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A robotic control design considering all the inherent nonlinearities of the robot-engine configuration is developed. The interactions between the robot and joint motor drive mechanism are considered. The proposed control combines two strategies, one feedforward control in order to maintain the system in the desired coordinate, and feedback control system to take the system into a desired coordinate. The feedback control is obtained using State-Dependent Riccati Equation (SDRE). For link positioning two cases are considered. Case I: For control positioning, it is only used motor voltage; Case II: For control positioning, it is used both motor voltage and torque between the links. Simulation results, including parametric uncertainties in control shows the feasibility of the proposed control for the considered system.

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Rats bearing lesions in the septal area followed by lesions in the subfornical organ were submitted to various thirst-eliciting procedures. The rats with hyperdipsia induced by lesions of the septal area drank more water than either during the control period or after lesion of the subfornical organ under the same thirst-eliciting or angiotensin-liberating stimuli (polyethyleneglycol, isoproterenol, water deprivation and ligation of the inferior vena cava). The overdrinking elicited by lesions in the septal area was blocked after lesion of the subfornical organ. Neither hypovolemia, nor hypotension or water deprivation could elicit increased water intake in animals whose subfornical organ had been destroyed. Animals with lesions in the subfornical organ showed decreased water intake after cellular dehydration. The results obtained suggest that the subfornical organ acts as a more important structure than the septal area in the regulation of water intake elicited by angiotensin, with two opposite effects: a direct one facilitating water intake, and an indirect one inhibiting the septal area. The septal area has an inhibitory effect on the subfornical organ and on water intake. © 1980.

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

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Abrasive wear is one of the most common type of wear that not only affect teeth, as also dental restorations. Thus to investigate one of the etiological factors as tooth brushing procedure is clinical relevant in order to select the best material combination that may prevent damage of resin dental restoration's abrasion. This study evaluated the influence of tooth brushing on mass loss and surface roughness of direct Venus (Vs) and indirect Signum (Sg) resin composites, with and without a surface sealant, Fortify (F). Twenty-four specimens were prepared with each resin composite, using their proprietary curing units, according to manufacturer's instructions. All the specimens were polished and ultrasonically cleaned in distilled water for 5 minutes. Half of the specimens of each resin (n = 12) were covered with F (Vs F and Sg F ), except for the control (C) specimens (Vs C and Sg C ), which were not sealed. Mass loss (ML) as well as surface roughness (Ra ) was measured for all the specimens. Then, the specimens were subjected to toothbrush-dentifrice abrasion, using a testing machine for 67.000 brushing strokes, in an abrasive slurry. After brushing simulation, the specimens were removed from the holder, rinsed thoroughly and blot dried with soft absorbent paper. The abrasion of the material was quantitatively determined with final measurements of ML and surface roughness, using the method described above. ML data were analyzed by two-way analysis of variance (ANOVA) and the analysis indicated that resin composites were not statistically different; however, the specimens sealed with F showed higher ML. Ra mean values of the groups Vs F and Sg F significantly increased. Tooth brushing affects mainly the roughness of the direct and indirect resin composites veneered with a sealant.

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Studies have reported that alcohol may lead to imbalance in bone formation and resorption, however, its effects on osseointegration of titanium implants continues to be an inconclusive subject. In this context, the aim of this study was to make a biomechanical evaluation of the effect of abusive alcohol consumption on the removal torque of osseointegrated titanium implants. Male Wistar rats (n=30) were divided into two experimental groups (15 each) receiving only water (Control) or 36% alcohol solution oral administration. Thirty days later, all animals were submitted to titanium implant (2.2 mm x 4 mm) placement in the right and left tibiae. The surgical alveoli were prepared with a 2 mm drill mounted in a counter-angle hand-piece (20:1 ratio, 35 Ncm torque at 1200 rpm) under abundant cooling. Five animals from each group were euthanized at 15, 30, and 60 days. Tibiae were submitted to reverse torque analysis. Data obtained were submitted to statistical analysis by the non-parametric Kruskal-Wallis and Dunn Tests (p < 0.05). Animals in the alcohol group presented lower removal torque values when compared with control group animals for all periods tested (p < 0.05). It can be concluded that abusive alcohol consumption can reduce the removal torque of titanium implants placed in rat tibiae, suggesting that alcohol may interfere in the osseointegration process of titanium implants.

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Studies have reported that alcohol may lead to imbalance in bone formation and resorption, however, its effects on osseointegration of titanium implants continues to be an inconclusive subject. In this context, the aim of this study was to make a biomechanical evaluation of the effect of abusive alcohol consumption on the removal torque of osseointegrated titanium implants. Male Wistar rats (n=30) were divided into two experimental groups (15 each) receiving only water (Control) or 36% alcohol solution oral administration. Thirty days later, all animals were submitted to titanium implant (2.2 mm x 4 mm) placement in the right and left tibiae. The surgical alveoli were prepared with a 2 mm drill mounted in a counter-angle hand-piece (20:1 ratio, 35 Ncm torque at 1200 rpm) under abundant cooling. Five animals from each group were euthanized at 15, 30, and 60 days. Tibiae were submitted to reverse torque analysis. Data obtained were submitted to statistical analysis by the non-parametric Kruskal-Wallis and Dunn Tests (p < 0.05). Animals in the alcohol group presented lower removal torque values when compared with control group animals for all periods tested (p < 0.05). It can be concluded that abusive alcohol consumption can reduce the removal torque of titanium implants placed in rat tibiae, suggesting that alcohol may interfere in the osseointegration process of titanium implants.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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A robotic control design considering all the inherent nonlinearities of the robot engine configuration is developed. The interactions between the robot and joint motor drive mechanism are considered. The proposed control combines two strategies, one feedforward control in order to maintain the system in the desired coordinate, and feedback control system to take the system into a desired coordinate. The feedback control is obtained using State Dependent Riccati Equation (SDRE). For link positioning two cases are considered. Case 1: For control positioning, it is only used motor voltage; Case 2: For control positioning, it is used both motor voltage and torque between the links. Simulation results, including parametric uncertainties in control shows the feasibility of the proposed control for the considered system.

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Management of wildlife disease can be targeted at pathogens, hosts or vector populations, but may also focus on the environment. As constituent elements of any given environment, resident wildlife populations, and their pathogens, may be profoundly influenced by environmental change, in terms of their abundance, distribution and behavior. Hence, it is reasonable to expect that incorporation of environmental manipulation into a program to control wildlife diseases may potentially result in outcomes as effective as direct intervention aimed at hosts, pathogens and vectors.

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The problem of rats in our Hawaiian sugar cane fields has been with us for a long time. Early records tell of heavy damage at various times on all the islands where sugar cane is grown. Many methods were tried to control these rats. Trapping was once used as a control measure, a bounty was used for a time, gangs of dogs were trained to catch the rats as the cane was harvested. Many kinds of baits and poisons were used. All of these methods were of some value as long as labor was cheap. Our present day problem started when the labor costs started up and the sugar industry shifted to long cropping. Until World War II cane was an annual crop. After the war it was shifted to a two year crop, three years in some places. Depending on variety, location, and soil we raise 90 to 130 tons of sugar cane per acre, which produces 7 to 15 tons of sugar per acre for a two year crop. This sugar brings about $135 dollars per ton. This tonnage of cane is a thick tangle of vegetation. The cane grows erect for almost a year, as it continues to grow it bends over at the base. This allows the stalk to rest on the ground or on other stalks of cane as it continues to grow. These stalks form a tangled mat of stalks and dead leaves that may be two feet thick at the time of harvest. At the same time the leafy growing portion of the stalk will be sticking up out of the mat of cane ten feet in the air. Some of these individual stalks may be 30 feet long and still growing at the time of harvest. All this makes it very hard to get through a cane field as it is one long, prolonged stumble over and through the cane. It is in this mat of cane that our three species of rats live. Two species are familiar to most people in the pest control field. Rattus norvegicus and Rattus rattus. In the latter species we include both the black rat and the alexandrine rats, their habits seem to be the same in Hawaii. Our third rat is the Polynesian rat, Rattus exlans, locally called the Hawaiian rat. This is a small rat, the average length head to tip of tail is nine inches and the average body weight is 65 grams. It has dark brownish fur like the alexandrine rats, and a grey belly. It is found in Indonesia, on most of the islands of Oceania and in New Zealand. All three rats live in our cane fields and the brushy and forested portions of our islands. The norway and alexandrine rats are found in and around the villages and farms, the Polynesian rat is only found in the fields and waste areas. The actual amount of damage done by rats is small, but destruction they cause is large. The rats gnaw through the rind of the cane stalk and eat the soft juicy and sweet tissues inside. They will hollow out one to several nodes per stalk attacked. The effect to the cane stalk is like ringing a tree. After this attack the stalk above the chewed portion usually dies, and sometimes the lower portion too. If the rat does not eat through the stalk the cane stalk could go on living and producing sugar at a reduced rate. Generally an injured stalk does not last long. Disease and souring organisms get in the injury and kill the stalk. And if this isn't enough, some insects are attracted to the injured stalk and will sometimes bore in and kill it. An injured stalk of cane doesn't have much of a chance. A rat may only gnaw out six inches of a 30 foot stalk and the whole stalk will die. If the rat only destroyed what he ate we could ignore them but they cause the death of too much cane. This dead, dying, and souring cane cause several direct and indirect tosses. First we lose the sugar that the cane would have produced. We harvest all of our cane mechanically so we haul the dead and souring cane to the mill where we have to grind it with our good cane and the bad cane reduces the purity of the sugar juices we squeeze from the cane. Rats reduce our income and run up our overhead.

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The remarks that I have prepared deal with direct contacts selling pest and bird control programs. I am going to limit my remarks to what I feel are the more important aspects of selling Bird Control. I think it is safe to say that one of the most difficult aspects of selling for most sales personnel is prospecting, that is, finding accounts to call on. Our sales personnel have to more or less come up with their own leads. They have to find out who to contact once they get there. I have found that the best prospect most of us have for selling Bird Control accounts are our present pest control accounts. Generally speaking, we try to main¬tain contact with our applicators in the field, who are in these accounts every day, asking them if there are any of their accounts that are having bird control problems. Another method of finding potential accounts, is driving around looking. It is more difficult to drive around and look for rat and/or roach problems, but generally speaking if a building or some type of business has a bird problem, it is fairly easy to locate. Another thing we can do is call on specific accounts. There are generally cer¬tain accounts that just by the manufacturing process do attract birds, for example: food plants, mills, beet plants, grain elevators, food processors, and so on. Other type operations which lend themselves to bird problems are industrial plants because of the super-structure (physical plant) that they have. Sub-stations and power plants are very attractive to birds. Some other situations that should be checked for bird problems are lumber yards and contractors' storage buildings. After deciding on a contact we get into what I call my basic four. There are four basic things that I try to impress upon our personnel to keep in mind when they go in to make a contact. The first one is the interview or actually making the contact so that you get an opportunity to have the interview, either calling for an appointment or making a "cold" call. The second one is closing for the survey. The third one is making the survey and preparing a proposal. The fourth and last one is the proposal presentation and closing of the sale. An additional item which would make a basic five is after you make the sale don't forget to follow up on the sale.

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Fogging of ReJeX-iT7 TP-40 offers a very efficient method for the control and dispersal of nuisance birds from many diverse areas. The amount of the repellent is greatly reduced over any other control method. The method is direct and is independent of the activity of the birds. The applications with any fogger, thermal or mechanical, that can deliver droplets of less than 20 microns, can be manually or fully automated and pose only minimal risks to operators or animals. All birds that became a nuisance and safety problem in the hangars of TWA and AA at LaGuardia, and TWA warehouse at Newark Airport were successfully driven out by fogging ReJeX-iT7 TP-40 with a Curtis Dyna-Fog AGolden Eagle@ thermal fogger.