scholarly journals Investigation of ultrasound pretreatment time and microwave power level on drying and rehydration kinetics of green olives

2020 ◽  
Author(s):  
Alev Yüksel AYDAR
Keyword(s):  
Microwave Power ◽  
Power Level ◽  
Pretreatment Time ◽  
Kinetics Of ◽  
Microwave Power Level ◽  
Ultrasound Pretreatment

Study of color kinetics of banana (Musa cavendish) under microwave drying by application of image analysis

2020 ◽  
pp. 108201322098133
Author(s):  
Sagar Nagvanshi ◽  
Subbarao Kotra Venkata ◽  
TK Goswami
Keyword(s):  
Microwave Power ◽  
Vision System ◽  
Power Level ◽  
Microwave Drying ◽  
Slice Thickness ◽  
Order Kinetic ◽  
Drying Time ◽  
Volumetric Heating ◽  
Kinetics Of ◽  
Microwave Power Level

Microwave drying works on the volumetric heating concept promoted by electromagnetic radiation at 0.915 or 2.450 GHz. In this study, banana ( Musa Cavendish) was taken as the sample and treated under microwave drying. The effect of two process variables, namely slice thickness (2, 3.5, and 5 mm) and microwave power (180 W, 360 W, and 540 W), were studied on drying kinetics and color kinetics. It was observed that the inverse variation relationship exists between drying time and microwave power level while drying time and slice thickness exhibited a direct variation relationship. A Computer Vision System (CVS) was developed to measure the color values of banana in CIELab space using an algorithm written in MATLAB software. Once the color parameters were obtained, they were fitted in First and Zero-order kinetic models. Both models were found to describe the color values adequately. This study concludes that microwave drying is a promising dehydration technique for banana drying that reduces the significant time of drying. Application of CVS is an excellent approach to measure the surface color of banana.

scholarly journals Drying Kinetics of Microwave-Dried Vegetable Amaranth (Amaranthus dubius) Leaves

2016 ◽  
Vol 5 (6) ◽  
pp. 33 ◽  
Author(s):  
Saheeda Mujaffar ◽  
Alex Lee Loy
Keyword(s):  
Microwave Power ◽  
Power Level ◽  
Initial Moisture Content ◽  
Chi Square ◽  
Warm Up ◽  
Higher Power ◽  
Rate Period ◽  
Drying Behaviour ◽  
Kinetics Of ◽  
Microwave Power Level

The effect of microwave power level (200, 500, 700 and 1000W) on the drying behaviour of amaranth (Amaranthus dubius) leaves was investigated. Higher microwave power levels effected faster drying and there was an increase in drying rate constant (k) as microwave power level increased from 200 to 1000W and an increase in diffusivity (Deff) values from 3.04 x 10-10 to 2.82 x 10-9 m2/s. Leaves dried at 1000W power level however showed noticeable scorching after 540s of drying. Drying at the lower microwave power levels occurred in the constant and falling rate period, while at the higher power levels drying occurred in the falling rate period after an initial warm-up phase. Amaranth leaves could be dried at 700W power from an initial moisture content of 6.00 g H2O/g DM (85.7% wb) to 0.08 g H2O/g DM (7.6% wb) in 11.5 min. Overall, of the twenty-two thin layer models applied to the MR data, the Alibas model gave the best fit in terms of both the root mean square error (RMSE) and the chi-square statistic (c2). 

Processing Parameters of Continuous Microwave Heating of Ethylene-Propylene Terpolymer

1984 ◽  
Vol 57 (1) ◽  
pp. 134-144 ◽  
Author(s):  
C. S. Wang
Keyword(s):  
Microwave Heating ◽  
Energy Absorption ◽  
Residence Time ◽  
Temperature Rise ◽  
Microwave Power ◽  
Power Level ◽  
Processing Parameters ◽  
Heating Process ◽  
Microwave Power Level ◽  
Absorption Characteristics

Abstract In continuous microwave heating, the temperature rise of rubber extrudates and the level of unabsorbed or reflected microwave power are strongly dependent upon the microwave power level, residence time, and extrudate configuration. It is therefore essential to control these processing parameters, together with the energy absorption characteristics of rubber materials, to improve the efficiency of microwave heating process.

Experimental Research on Tensile Strength Reduction of Concrete Caused by Microwave Irradiation

2013 ◽  
Vol 405-408 ◽  
pp. 2789-2794 ◽  
Author(s):  
Jun Dai ◽  
Dong Cao
Keyword(s):  
Tensile Strength ◽  
Microwave Irradiation ◽  
Experimental Research ◽  
Exposure Time ◽  
Microwave Power ◽  
Power Level ◽  
Strength Reduction ◽  
Test Method ◽  
Microwave Exposure ◽  
Microwave Power Level

In order to understand the law on concrete degradation induced by microwave irradiation, the experimental research is conducted in which the following works are completed. At first, the different concrete specimens are exposed to microwave of various power levels for various time periods, and then some specimen irradiated by microwave are cooled in air, the other cooled by spraying water. After that, the tensile strengths of the heated and unheated specimens are measured with Brazilian test method. According to the test results, the reduction of tensile strength of plain concrete and steel-fiber reinforced concrete induced by microwave irradiation is analyzed, and the relations between the tensile strength reduction and the microwave exposure time and the effect of microwave power level on the residual tensile strength of concrete are obtained. The experimental research shows that the tensile strength reduction of concrete induced by microwave irradiation is dependent on the concrete component, microwave exposure time, microwave power level, and cooling method after irradiation. It is expected that the findings in the paper will become the basis of the future research of concrete and rock degradation induced by microwave irradiation, and will aim in searching the new method of breaking concrete and rock more efficiently.

scholarly journals Screening of Microwave-Assisted-Batch Extraction Parameters for Recovering Total Phenolic and Flavonoid Contents from Chromolaena odorata Leaves through Two-Level Factorial Design

2019 ◽  
Vol 19 (2) ◽  
pp. 511 ◽  
Author(s):  
Oluwaseun Ruth Alara ◽  
Abdurahman Hamid Nour ◽  
Siti Kholijah Binti Abdul Mudalip
Keyword(s):  
Factorial Design ◽  
Microwave Power ◽  
Ethanol Concentration ◽  
Irradiation Time ◽  
Power Level ◽  
Feed Ratio ◽  
Total Phenolic ◽  
Chromolaena Odorata ◽  
Microwave Assisted ◽  
Microwave Power Level

Microwave-assisted extraction (MAE) of phenolic compounds from Chromolaena odorata leaves was investigated using one-factor-at-a-time (OFAT) and two-level factorial design. The MAE parameters studied were irradiation time (A: 1–5 min); microwave power level (B: 400-800 W); extraction temperature (C: 60–80 °C); solvent/feed ratio (D: 8:1–14:1 mL/g); and ethanol concentration (E: 20–60% v/v). The optima yields of TPC and TFC were 56.13 mg GAE/g d.w. and 44.78 mg QE/g d.w., respectively were achieved from MAE of C. odorata leaf at irradiation time of 2 min, microwave power of 600 W, temperature of 60 °C, solvent:feed ratio of 10:1 mL/g, and ethanol concentration of 40% v/v through one-factor-at-time (OFAT) experimental trials. The results obtained from a two-level factorial design experiments reflected that only ethanol concentration (20–60% v/v), irradiation time (1–5 min) and microwave power level (400–800 W) had significant effects on the yields of total phenolic content (TPC) and total flavonoid content (TFC) from C. odorata leaves (p < 0.05). However, temperature and solvent/feed ratio was not significant. In addition, the interactions AB (irradiation time and microwave power) and AE (irradiation time and ethanol concentration) contributed greatly to the recovery yields.

Study the Effect of Change in Microwave Power Level in Organic Reactions Using Heterogenous Mont. K-10 Catalyst

2007 ◽  
Vol 4 (1) ◽  
pp. 171-173
Author(s):  
RAVINDER SINGH ◽  
MUKESH RANI ◽  
SUMITA RANI ◽  
SUMEDHA MALIK
Keyword(s):  
Microwave Power ◽  
Power Level ◽  
Organic Reactions ◽  
Microwave Power Level

Effects of lignocellulosic composition and microwave power level on the gaseous product of microwave pyrolysis

Energy ◽  
2015 ◽  
Vol 89 ◽  
pp. 974-981 ◽  
Author(s):  
Yu-Fong Huang ◽  
Pei-Te Chiueh ◽  
Wen-Hui Kuan ◽  
Shang-Lien Lo
Keyword(s):  
Microwave Power ◽  
Power Level ◽  
Gaseous Product ◽  
Microwave Pyrolysis ◽  
Microwave Power Level
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