861 resultados para transit efficiency
Resumo:
The objectives of the present study were to evaluate the safety of mixer/loaders and applicators of paraquat to maize crop by knapsack sprayers and to determine the efficacy of safety measures applied to the sprayers. Potential dermal exposure (PDE) was evaluated in 22 worker body parts. The Cu2+ cation of a copper-based fungicide was used as tracer in the spray solution. Sanitary pads and cotton gloves were used to collect the pesticide solution on the sampled body parts. It was observed that paraquat application in front of the applicator's body (0.5 and 1.0 m lance) is unsafe because PDE was 1,979.8 ml/day (for 0.5 m lance) and 1,290.4 ml/day (for 1.0 m lance) and needs 50-80% and 37-69% control of PDE respectively. Control can be achieved by the use of protective garment on the legs and feet only, which received 92-93% of the PDE. Switching the spray nozzle to the back of the operator reduced the PDE by 98% and was sufficient to make working conditions safe, while maintaining the efficiency of application and making the work lighter and more comfortable. Mixer/loaders received 86% of the PDE to the hands and the work condition was safe (MOS > 1), however impermeable gloves could be used as a further safety measure.
Resumo:
Hrp1p is a heterogeneous ribonucleoprotein (hnRNP) from the yeast Saccharomyces cerevisiae that is involved in the cleavage and polyadenylation of the 3'-end of mRNAs and mRNA export. In addition, Hrp1p is one of several RNA-binding proteins that are posttranslationally modified by methylation at arginine residues. By using-functional recombinant Hrp1p, we have identified RNA sequences with specific high affinity binding sites. These sites correspond to the efficiency element for mRNA 3'-end formation, UAUAUA. To examine the effect of methylation on specific RNA binding, purified recombinant arginine methyltransferase (Hmt1p) was used to methylate Hrp1p. Methylated Hrp1p binds with the same affinity to UAUAUA-containing RNAs as unmethylated Hrp1p indicating that methylation does not affect specific RNA binding. However, RNA itself inhibits the methylation of Hrp1p and this inhibition is enhanced by RNAs that specifically bind Hrp1p. Taken together, these data support a model in which protein methylation occurs prior to protein-RNA binding in the nucleus.
Resumo:
A low-voltage, low-power four-quadrant analog multiplier with optimized current-efficiency is presented. Its core corresponds to a pseudodifferential cascode, gain-boosting triode-transconductor. According to a low-voltage 1.2μm CMOS n-well process, operand differential-amplitudes are 1.0Vpp and 0.32Vpp for a 1.3V-supply. Common-mode voltages are properly chosen to maximize current-efficiency to 58%. Total quiescent dissipation is 260μW. A range of PSPICE simulation supports theoretical analysis. Excellent linearity is observed on dc characteristic. Assuming a ±0.5% mismatch on (W/L) and VTH THD at full-scale is 0.93% and 1.42%, for output frequencies of 1MHz and 10MHz, respectively.
Resumo:
This paper presents a high efficiency Sepic rectifier for an electronic ballast application with multiple fluorescent lamps. The proposed Sepic rectifier is based on a Zero-Current-Switching (ZCS) Pulse-Width-Modulated (PWM) soft-commutation cell. The high power-factor of this structure is obtained using the instantaneous average-current control technique, in order to attend properly IEC61000-3-2 standards. The inverting stage of this new electronic ballast is a classical Zero-Voltage-Switching (ZVS) Half-Bridge inverter. A proper design methodology is developed for this new electronic ballast, and a design example is presented for an application with five fluorescent lamps 40W-T12 (200W output power), 220Vrms input voltage, 130Vdc dc link voltage, with rectifier and inverter stages operating at 50kHz. Experimental results are also presented. The THD at input current is equal to 6.41%, for an input voltage THD equal to 2.14%, and the measured overall efficiency is about 92.8%, at rated load.
Resumo:
It was evaluated the energetic efficiency and operational parameters of a windrowing and prismatic baling, both from CASE NEW HOLLAND® operations in sugarcane vegetal residues (green leaves, dry leaves and tops) picked mechanically in green cane. The area belongs to COSTA PINTO MILL (COSAN® Group) which was harvested mechanically by combines in the State of Sao Paulo, Brazil. The geographic location of the area is: Latitude 22°40'30S, Longitude 47°36'38W and Altitude of 605m. The variety was RB 82-5336, planted in 1.40m row spacing, with 78t.ha-1 yield. The vegetal residues analysis obtained 69.93% of leaves, 21.44% of stalks fractions, 2.27% of tops and 6.36% of total strange matter. The vegetal residues values were: gross heat of 18.43MJ.kg-1, low heat of 17.00MJ.kg'1 and useful heat of 12.94MJ.kg-1. The vegetal residues average energetic potential was 342.48GJ.ha-1. The treatments were simple, double and triple windrowing. The use of the rake and prismatic baler to pick up the residues was viable. The simple windrowing treatment presented the best results: effective capacity of 83.06t.ha-1, fuel consumption of 0.18L.t -1 and 99.95% of positive energetic efficiency. The bales obtained in the treatment of triple windrowing presented the largest specific mass average of 221.11kg.m-3. The soil amount in the bales increased with successive windrowing. The baling operation in the triple windrowing treatment obtained better results, presenting the effective capacities of 20.29t.h -1 and 1.45ha.h-1 and fuel consumption of for baled in 1.37L.t-1. The high total energetic efficiency of 99.53% indicates that is technically viable the withdrawal of the vegetal residues.
Resumo:
The objective of this study was to analyze the sugar cane vegetal residues collection, as well as determining its energetic potential, using a rake and cylindrical baler, both from NEW HOLLAND® under two different windrowing process (simple and double). The field tests were carried out in an area that belongs to COSTA PINTO MILL (COSAN® Group) in the city of Piracicaba, Sao Paulo State, Brazil. The geographic location of the area is: Latitude 22°4030'S, Longitude 47°3633'W and altitude of 605m. From the trash analysis, before the baling, the following average results were obtained: 69.93% of leaves; 2.27% of stalks fractions; 21.44% of tops and 6.36% of total strange matter. The estimated residues yield was 27.01 tons.ha -1 with a gross heat of 18.43 MJ.kg-1, low heat of 17.01 MJ.kg-1, useful heat of 13.32 MJ.kg-1, average moisture of 20.76% and an energetic potential of 494,875.09 MJ.ha-1. In the windrowing operations (simple and double) the averages of the 5 out of 13 analyzed variable presented differences between them in a 1% level of significance in the Tukey Test. The averages comparison of the results for bale's specific mass and the effective capacities (ton.h-1) e (ha.h-1) had been significant at a 5% level in the Tukey Test. The comparisons of the averages for the results had been significant to 1% level. The strange matter averages of the bales did not differed between them.
Resumo:
The conventional, grinding methods in some cases are not very efficient because the arising of thermal damages in the pieces is very common. Optimization methods of cutting fluid application in the grinding zone are essential to prevent thermal problems from interaction of the wheel grains with the workpiece. surface. The optimization can happen through the correct selection of the cut parameters and development of devices that eliminate air layer effects generated around the grinding wheel. This article will collaborate with the development of an experimentation methodology which allows evaluating, comparatively, the performance of the deflectors in the cutting region to minimize the air layer effect of the high speed of the grinding wheel. The air layers make the cutting fluid jet to dissipate in the machine. An optimized nozzle was used in order to compare the results with the conventional method (without baffles or deflectors) of cutting fluid application. The results showed the high eficciency of the deflectors or baffles in the finish results. Copyright © 2006 by ABCM.
Resumo:
Outsourcing is related to the action which an organization deals with its suppliers through a kind of business contract where a specific activity or service has been hired to be made. The outsourcing of some activities has become a common practice in the industry, nowadays. It reduces costs, significantly, in the production process and, at the same time, adds some values to the business organization. However it is necessary to measure the performance of these activities. Data Envelopment Analysis (DEA) is a non-parametric method useful to measure comparative performance. It has a wide range of applications measuring comparative efficiency. The Analytic Hierarchy Process (AHP) is a multiple criteria decision-making method that uses hierarchic structures to represent a decision problem and then develops priorities for the alternatives based on the decision-maker's judgments. This paper presents an integrated application based on DEA and AHP to evaluate the efficiency of subcontracted companies in a Brazilian aerospace factory. © 2007 Springer-Verlag London Limited.
Resumo:
The energy efficiency of buildings should be a goal at the pre-design phase, though the importance of the design variables is often neglected even during the design process. Highlighting the relevance of these design variables, this research studies the relationships of building location variables with the electrical energy consumption of residential units. The following building design parameters are considered: orientation, story height and sky view factor (SVF). The consideration of the SVF as a location variable contributes to the originality of this research. Data of electrical energy consumption and users' profiles were collected and several variables were considered for the development of an Artificial Neural Network model. This model allows the determination of the relative importance of each variable. The results show that the apartments' orientation is the most important design variable for the energy consumption, although the story height and the sky view factor play a fundamental role in that consumption too. We pointed out that building heights above twenty-four meters do not optimize the energy efficiency of the apartments and also that an increasing SVF can influence the energy consumption of an apartment according to their orientation.
In vitro antimicrobial efficiency of a mouthwash containing triclosan/gantrez and sodium bicarbonate
Resumo:
Several antiseptic substances have been used as adjuncts to routine mechanical procedures of oral hygiene, based on their antimicrobial effects. The objective of this study was to assess in vitro the antimicrobial efficiency of 2 mouthwash containing Triclosan/Gantrez and sodium bicarbonate in comparison to both positive and negative controls. Standard strain samples of Escherichia coli, Pseudomonas aeruginosa, Actinomyces viscosus and Bacillus subtilis were used. Samples of Streptococcus mutans and Gram-negative bacilli were collected from 20 volunteers (10 with a clinically healthy periodontium and 10 presenting biofilm-associated gingivitis). Evaluation of the antimicrobial activity was performed by determining the minimal inhibitory concentration (MIC). The results indicated that the test solution inhibited the growth of both Gram-negative and Gram-positive microorganisms from the volunteers' saliva as well as that of the standard strains at the MIC dilution of 1:20, whereas the MIC dilution of 0.12% chlorhexidine against the same bacteria was 1:80. Thus, even though the tested mouthrinse solution presented an in-vitro antimicrobial activity superior to that of a placebo, it was inferior to that of chlorhexidine.
Resumo:
The restoration of masticatory function and esthetics is an important aim in dentistry mainly when patients present with extensive tooth loss. The aim of mastication is to reduce food size to produce a homogeneous bolus appropriate to be swallowed. For edentulous patients, chewing efficiency is reduced because dental arches are replaced by artificial teeth. The aim of this study is to present factors related to chewing efficiency for the edentulous patient.
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This paper presents a proposal of a model to measure the efficiency of outsourced companies in the aeronautical industry applying the methods DEA and AHP. It also proposes an evaluation in the relation between the variables of the process and the value obtained for the effiiency. The criteria of Quality, Time and Cost were considered the outputs of the process, and those criteria were quantified by AHP for DEA matrix.The number of technical documents received by those outsorced companies were considered the input of the process. The other purpose is to separate the companies in groups considered able to receive an investment to improve their process. Copyright © 2008 SAE International.
Resumo:
This paper proposes an alternative codification to solve the service restoration in electric power distribution networks using a SPEA2 multiobjective evolutionary algorithm, assuming the minimization of both the load not supplied and the number of switching operations involved in the restoration plan. Constrains as the line, power source and voltage drop limits in order to avoid the activation of protective devices are all included in the proposed algorithm. Experimental results have shown the convenience on considering these new representations in the sense of feasibility maintenance and also in the sense of better approximation to the Pareto set. ©2009 IEEE.