Artigos científicos, teses e dissertações
Publicados nas melhores instituições de ensino

Comparison of Effects of Sublethal Microwave Radiation and Conventional Heating on the Metabolic Activity of Staphylococcus aureus†

This study was conducted in an attempt to characterize some of the effects of sublethal microwave radiation on cells of Staphylococcus aureus. Cultures were exposed to microwave radiation for 10, 20, 30, and 40 s. The effects of a conventional heat treatment were also compared by...

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Inhalation trauma due to overheating in a microwave oven.

The microwave oven is a kitchen appliance that has become increasingly popular in recent years. In some instances the temperature in the microwave oven can become exceedingly high. A case is discussed of a patient with respiratory distress after inhalation of gas from an overheat...

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Effect of microwave radiation on inactivation of Clostridium sporogenes (PA 3679) spores.

Three techniques for studying effects of microwave radiation on microorganisms were introduced. Spores of Clostridium sporogenes (PA 3679) were chosen as a test organism because the kinetic parameters for thermal inactivation are well known and because of the importance of the ge...

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Aquecimento em forno de microondas / desenvolvimento de alguns conceitos fundamentais

The microwave oven became a common domestic equipment, due mainly to the short time spent to heat foods. One of the most interesting characteristics of the microwave oven is the selective heating. Different from the conventional oven, where the heating is not selective, the heati...

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Microondas em síntese orgânica

The application of microwave heating to organic synthesis is presented in a concise manner. Issues such as the history of the microwave oven, dielectric heating, reactions techniques (dry reactions, MORE chemistry), domestic ovens, microwave reactors, microwave effect and control...

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Microwave Sterilization of Femoral Head Allograft

The potential shortage of allograft bone has led to the need to investigate other sources of bone for allografts. Some allograft bone donated from primary total hip arthroplasty recipients must be discarded or treated to become useable as a result of bacterial contamination. Femo...

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Influence of microwave processing on the bioactive compounds, antioxidant activity and sensory acceptance of blackberry jelly

Abstract The purpose of this study was to evaluate the effect of microwave and microwave combined with vacuum on the nutritional and sensory characteristics of blackberry jelly, in order to verify if they are actually more viable methods of processing when compared to the traditi...

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Adaptação de forno de microondas doméstico para realização de reações de transesterificação sob refluxo e catálise por argilas

The microwave oven became an important source of heating for many laboratory procedures including accelerating organic reactions. Reactions that require long reflux times can sometimes be carried out in a few hours or minutes in a conventional microwave oven. However, longer refl...

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Electrooptic combinator for ultra-fast pulsed microwave signal generation / Combinador eletro-optico para geração de sinais pulsados ultra-rapidos de microondas

A novel technique of pulsed microwave waveform generation has been developed. It is based on the mixture of two arbitrary signals, an ultra-fast pulse train and a microwave carrier, all generated from different sources and combined in the optical domain in order to preserve the s...

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Analysis of heat and mass transfer during microwave drying of food products

Microwave (MW) drying is a rapid dehydration technique that can be applied to specific foods. Increasing concerns over product quality and production costs have motivated the researchers to investigate and the industry to adopt microwave drying technology. The advantages of micro...

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Microwave cyclodestruction: evaluation on human eyes.

AIMS--The study was set up to evaluate the effect of microwave cyclodestruction on human eyes. METHODS--Two human eyes were studied. For treatment a horn shaped 5.8 GHz microwave applicator and fibre optic thermometry were used. Just before enucleation, the rectangular (2 x 3 mm)...

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Microwave antigen retrieval in immunocytochemistry: a study of 80 antibodies.

AIMS--To evaluate the effect of microwave irradiation on the staining quality of a range of commonly used primary antibodies in archival, formalin fixed, paraffin wax embedded material, with emphasis on antibodies that have previously worked successfully only on frozen tissue. ME...

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Experimentos didáticos envolvendo radiação microondas

Theoretical and practical aspects of the use of microwave-assisted strategies in chemistry are introduced for students using simple and safe experiments employing a domestic oven. Three procedures are proposed for evaluating the distribution of microwave radiation inside the micr...

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Procedure for Evaluating the Effects of 2,450- Megahertz Microwaves upon Streptococcus faecalis and Saccharomyces cerevisiae1

Modifications of a commercial 2,450-megahertz microwave oven were made so that 6 ml of microbial suspension could be exposed to the microwave field for various periods of time. The microorganisms were contained in the central tube of a modified Liebig condenser positioned in the ...

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Effect of disinfection techniques on physical-mechanical properties of a microwave-activated acrylic resin

Abstract The effects of disinfection by microwave irradiation and immersion in peracetic acid on the physical-mechanical properties of a microwave-activated acrylic resin were evaluated. Specimens of acrylic resin were divided into a control group (specimens not disinfected) and...

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Investigate the Effect of Dielectric Properties on Microwave Absorption of Pyramidal Microwave Absorber

Abstract This paper presents an analysis of the impact of various dielectric properties material’s effects on broadband pyramidal microwave absorbers (PMA). The Computer Simulation Technology (CST) studio software simulates and analyzes the PMA over 0.7 GHz to 30 GHz frequency ra...

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WC-Co Particles Reinforced Aluminum Matrix by Conventional and Microwave Sintering

Metal matrix composites of Al-WC (10, 15 and 20 wt%) were prepared by microwave (without holding) and conventional sintering (held for 1 hour) processes at various temperatures between 650-950 °C. The results indicated that the highest density of conventional and microwave sinter...

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Experimental study of dehydration processes of raspberries (Rubus Idaeus ) with microwave and solar drying

Abstract The aim of the present study was to evaluate the effect of solar and microwave drying on raspberries (Rubus Idaeus) cv. Heritage. The efficiency of drying was evaluated in terms of weight reduction in function of the time. The quality properties evaluated were color, te...

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Immunohistochemical analysis of Hodgkin's disease using microwave heating.

AIMS--To assess the effect of microwave heating on immunohistochemical staining of CD15 and CD30 antigens in Hodgkin's disease tissue samples. METHODS--Formalin fixed, paraffin wax embedded sections from 20 cases of Hodgkin's disease (six mixed cellularity, 14 nodular sclerosis) ...

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Differential Damage in Bacterial Cells by Microwave Radiation on the Basis of Cell Wall Structure

Microwave radiation in Escherichia coli and Bacillus subtilis cell suspensions resulted in a dramatic reduction of the viable counts as well as increases in the amounts of DNA and protein released from the cells according to the increase of the final temperature of the cell suspe...

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Mathematical modeling of microwave dried celery leaves and determination of the effective moisture diffusivities and activation energy

Celery (Apium graveolens L. var. secalinum Alef) leaves with 50±0.07 g weight and 91.75±0.15% humidity (~11.21 db) were dried using 8 different microwave power densities ranging between 1.8-20 W g-1, until the humidity fell down to 8.95±0.23% (~0.1 db). Microwave drying processes...

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