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Research field: The research activities of this laboratory are: 1) Study and measurement of physical, mechanical and
Expert: Akbar Kolivand
Phone: 021-48292479
Address:
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Introduction One of the most important and sensitive steps after walnut harvesting is the separation of the kernel from its shell. Walnut rupture force is an appropriate criterion for design with high performance and better quality, which can be used as the basis for designing and adjusting the various parts of machines that are in contact with walnut. The lower rupture force caused the less energy requirement to separate the walnut kernel from the shell. The use of ultrasound in ambient fluids is well known to cause turbulence and biological cell rupture. These effects arise principally from the phenomenon known as cavitation which can scour surfaces and damage cellular material. Therefore the object of this study is to find the effect of
In this study, the effect of microwave drying method (at five power levels: 200, 400, 600, 800 and 1000 watts) on drying time, color color Subject Category: Properties
In this research, sour cherry juice (SCJ) was treated using a combination of the Ultrasound‐Pulsed electric field (UP) wave and Hydrodynamic‐Pulsed electric field (HP) systems. The main objective of this study was to investigate the effect of the combination of the pulsed electric field, ultrasonic wave, and hydrodynamic as new non‐thermal technologies on the inactivation of microorganisms, energy changes in one cycle of E. coli inactivation, and the quality of SCJ. The range of experimental conditions was as follows: electrical field intensity: 5–10?kV/cm, electric field time: 5–35?s, ultrasound power: 100–200?W, ultrasonic exposure time: 3–5?min, and hydrodynamic exposure time: 3–9?min. The results of the treatments indi
Herb stems and leaves must be sheared and separated before any processing and post harvest operations. This is non-mechanized since parts of the stem having fewer leaves are cut manually. This research is focused on the design and development of an automated machine for precise cutting of harvested herb stems. The system detects plant's leafy area from the leafless stem section by using machine vision. For this purpose, herb stems are placed in clamps fixed on a conveyor belt. A digital camera takes images of the passing samples. Image processing is performed to determine the proper cutting position on the stem. The shearing system is then vertically moved to the determined cutting position to make a precision cut. The designed system cuts
In this research, for the first time a mixture of diesel-biodiesel-water-bionanoparticles was prepared to simultaneously optimize the fuel consumption, reduce pollutant emission, and enhance the performance of diesel engines. To this end, graphene quantum dots as biodegradable nanoparticles were synthesized through the hydrothermal method. In this respective, the synthesized quantum dot nanoparticles were added at the concentrations of 20, 60, and 100 ppm along with 1, 5, and 10 vol.% distilled water to the B15 fuel (the diesel fuel containing 15 vol.% biodiesel). The results obtained from the engine experiments exhibited that when water and quantum dots were added simultaneously to the B15 fuel, the engine power was increased and the brake
Quality assessment of fruits and vegetables is important for all involved in production, processing, trading and even consumption of the products. This study was conducted for non-destructive estimation of moisture content (MC), soluble solids content (SSC), pH and firmness of Gala apple samples using near-infrared spectroscopy in the 350–2500 nm range by application of wavelet transform for pre-processing of raw spectral data. Wavelet transform was combined with other usual pre-processing functions widely used for constructing PLS regression models. The models' predictive capability was evaluated using correlation coefficient of determination (R2), root mean square error of estimation (RMSE) and correlation coefficient (R). The best ca
The purpose of this research was to predict and optimize the fish biodiesel characteristics using its permittivity properties. The parameters of biodiesel permittivity properties such as έ, dielectric constant, and ε ″, loss factor at microwave frequencies of 434, 915, and 2,450 MHz, were used as input variables. The fish biodiesel characteristics, as Fatty Acid Methyl Ester (FAME) content and flash point at three different levels of reaction time 3, 9, and 27 min and catalyst concentrations 1, 1.5, and 2% ww oil-1, were selected as output parameters for the models. Linear Regression (LR), the Multi-Layer Perceptron (MLP), and the Radial Basis Function (RBF) as the methods of Artificial Neural Networks (ANN), and the response surface me
The tendency toward research on the production and application of renewable energy, such as biodiesel, to reduce greenhouse gases and emissions of fossil fuels, is one of the most important issues in the world policies which has been discussed. Dielectric properties (ε’, dielectric constant and ε", dielectric loss factor) of materials play a major role in the microwave design and process of biodiesel production. The purpose of this research is to investigate and evaluate the biodiesel's dielectric properties in a pilot-scale using microwave technology and the relationship between its various effective parameters. In this study, the effects of reaction time (1, 3 and 9 minutes), catalyst concentration (1, 1. 5 and 2% of oil weight) and t
The usage of biodiesel quality monitoring system (online and batch) is always the basic requirement of its production which requires to research in this area. The purpose of this study is to predict and optimize the palm biodiesel characteristics using its permittivity properties. The parameters of biodiesel permittivity properties (ε’, dielectric constant and ε ″, loss factor) at microwave frequencies of (434, 915 and 2450 MHz) were used as input variables. The palm biodiesel characteristics as fatty acid methyl ester (FAME) content and flash point (FP) at three different level of reaction time (3, 9 and 27 min) and catalyst concentration (1, 1. 5 and 2% w/woil) were selected as output parameters for the models. The response surface
So far, many studies have been conducted on heat transfer nanofluids and various nanofluids have been synthesized and evaluated by different nanoparticles. In the present research, the use of biodegradable carbon quantum dots (CQDs) to synthesize heat transfer nanofluids was investigated for the first time. In fact, CQDs are a new generation of carbon nanoparticles and one of the advantages of which is their very small size that facilitates the prepared of nanofluids at very low concentrations with high stability. In the present research, CQDs were synthesized based on microwave method using commercial ammonium hydrogen-citrate as precursor. The nanofluid samples were synthesized based on car radiator coolant and CQDs at the concentrations
Nowadays, energy is the most challenging issue in the world. Although nanotechnology has been promising in offering huge developments in various fields, there are still concerns about the potential threats of nanotechnology products and applications. The concerns are mostly about the possible entrance of nanoparticles into body and their toxicity. As metallic and metal oxide nanoparticles might have toxic effects on living organisms, the use of biocompatible nanoparticles can considerably reduce these concerns. In this research, a combination of diesel-biodiesel-water-biodegradable nanoparticles was used to optimize fuel consumption, reduce pollutants, and enhance diesel engine performance for first time. Carbon quantum dot nanoparticles we
The present study investigated the influence of air temperature and velocity on the drying kinetics and specific energy consumption during fluidized bed drying of soybean at 80, 100, 120 and 140?C and airflow rates of 1.8, 3.1 and 4.5 m s-1. Six mathematical models for describing the fluidized bed drying behavior were investigated. The value of the drying rate coefficient (k) increased with increasing air temperature and velocity and thus reduced the drying time. Although the Midilli model showed the best fit, the Page's model was selected, since it had almost a similar performance but the model is simpler with two parameters instead of four. The drying of soybean seeds took place in the falling rate period and was controlled by moisture di
A method based on Machine Vision System (MVS) is he reby employed to evaluate grape drying through an assessment of the fruit’s s hrinkage and quality during the dehydration. Experimental data as well as captured images are obtained at an air velocity of 1.4 m s -1 and different drying temperatures (50, 60, 70?C). The results indicated the effect of temperature on the moisture content, shri nkage and color changes. The moisture content along with color changes ( ∆ E) were modeled and linear regressions applied to correlate the fruit’s shrinkage as well as color fe atures to the moisture content. The results obtained, displayed that there existed good linear relat
This study aimed to examine the effectiveness of co mbined microwave-ultrasonic pasteurization system on Escherichia coli and vitamin C content in sour cherry juice (SCJ). Based on the findings, microwave output powe r, ultrasound power, and ultrasonic exposure time as well as the microwave-induced temp erature were the most effective factors in reducing E. coli and vitamin C content. In addition, the microwave-i nduced temperature and ultrasonic exposure time, as indepe ndent variables, were both effective on E. coli removal. At higher temperatures, the effectiveness of ultrasonic waves as well as cavitation intensity declined. However, their combi ned effect
Initial low cost of pesticides and lack of knowledge on the part of agricultural producers has led to an overuse of pesticides, with dangerous consequences. On the other hand, today pesticides have an important role in the increment of agriculture products. Therefore, in recent years, the major aims of agricultural, environmental and even the food industry researchers have been to reduce the usage of chemical materials in agricultural applications. To achieve this, variable rate application in sprayers using different technologies such as machine vision, ultrasonic sensors, spectrometry, laser scanning, as well as pest identification and classification, have been applied in recent studies. This paper reviews these works reported in the 21 c