فهرست مطالب m. zandi

If spermatogonial stem cells (SSCs) are transplanted into the testicles of lambs that do not have this type of cell, they begin to produce sperm in the testis of the recipient rams. The aim of this study was to prepare recipient lambs. For this purpose, heat treatments of 35, 45, 55 and 65 °C or water-ice treatment for 20, 40 and 60 minutes were used for three replicates with two days interval. The results showed that the condition of the testicles was normal at 45 °C, but the treatment at 55 °C caused infection in the seminiferous tubules and at 65 °C, the testicles were completely destroyed. The use of water-ice treatments did not change the appearance of the testes. Colony formation after extraction and culture of SSCs at 45 °C treatment and water-ice treatments were significantly reduced compared to the control (P <0.05). Also, the expression of c-myc, plzfand gfrl genes as specific SSC markers was significantly reduced in 45 °C and cold treatments compared with the control (P <0.05). Accordingly, for reducing the number of SSCs in lambs’ testicles, water ice or 45 °C treatments for 20 minutes can be used three times at intervals of two days.

Nowadays, the selection of probiotics has an important role in the development of the country's food industry and the production of probiotic dairy products is the main indicator of this progress on the other hand, the quality, sensory and viability characteristics of probiotics in manufactured products are the main problems of most industrial factories.

the effect of different concentrations of kombucha drink on the viability of Lactobacillus acidophilus, bifidobacterium bifidum, Lactobacillus Rhamnosus was studied and physicochemical and sensory characteristics of fermented milk were measured during 28 days of storing period at 5±1˚C. Different levels of Kombucha tea 0, 5, 10, 15 and 20 ml/L were added to probiotic fermented milk containing L. acidophilus, B. bifidum, L. Rhamnosus bacteria (Cfu/ml 107) .Viability rate of probiotic bacteria, pH, percentages of protein, acidity(Dornic), acetic acid, antioxidant compounds were measured during 3, 7, 14 and 28th of storing period at 4 ⸰C.

Results showed that higher amounts of kombucha cause higher content of protein, acidity, acetic acid and antioxidant activity. The average amounts of theses parameters were respectivly 0.12,0.02, 15.694 and 0.16. however, pH and viability of probiotic bacteria significantly decreased during the storage period(p<0.05) and average amounts of these parameters were respectively0.79 and 0.046, However, the mentioned indices were higher than the acceptable standard of probiotic products.

the addition of kombucha up to 5% could be more effective in improving sensory characteristics. Hence, a treatment containing 5% of kambucha was selected as the best among others.

The current work proposed a novel fuzzy-based multi-criteria decision-making method to assess the development potential of wind power plants in a country. Type-2 fuzzy logic was utilized to investigate the simultaneous effects of several technical criteria such as wind conditions, ambient temperature, and dust activities in a site. Iran was chosen as the case study, considering the various environmental conditions and the lack of thorough investigations in the country. The proposed method could be easily extended to apply to any region. The related technical data for all the 559 Synoptic meteorological stations in the country were collected and used as the inputs for the proposed method. Applying two-step interviews with local experts and reviewing the literature, the leading indicators and their effectiveness were defined. After developing the fuzzy rules and sets, all the sites were scored and ranked using type-2 fuzzy logic in the proposed method. Based on the final standings, priority tables were provided and the top fifty sites for implementing offshore and onshore wind power plants were introduced. Moreover, primary analysis of the collected data indicated that the provinces with high energy consumption and high PM 2.5 levels are in critical environmental conditions. Thus, these provinces need strict attention and planning for sustainable energy supply using renewable energy systems. Based on the results, several recommendations and suggestions were also mentioned to organize investment resources for a more efficient and proper power plant development as well as future studies.

Vehicular communications have been considered to be an enabler for numerous vehicle safety and information applications.Vehicle Social Networks (VSNs) are a type of ad-hoc networks which allows wireless communication between two adjacent vehicles. Routing and communicating with adjacent nodes are one of the problems in VSNs. A literature review indicated that the time limit to transmit data and route is a problem due to the geographical distance and speed..

Large amplitude inter-well oscillations in bi-stable energy harvesters made them a proper energy harvesting choice due to high energy generation. However, the co-existence of the chaotic attractor in these harvesters could essentially decrease their efficiency. In this paper, an algorithm for detecting chaos in bi-stable energy harvesters based on a data-gathering algorithm and estimating the largest Lyapunov exponent is investigated. First, a simple model of axially loaded non-linear energy harvesters is derived. This model is derived using the Euler-Bernoulli beam theory and the Assumed Mode method considering the Von-Karman non-linear strain-displacement equation. The harvester's numerical simulation results are used to test the algorithm's efficiency and accuracy in identifying chaotic response. The results showed the algorithm's success in detecting chaos in such systems with minimum possible calculation cost. The effect of noise on the algorithm's performance has been investigated, and the results showed the excellent robustness of the algorithm to noise. It can diagnose the harvester's chaotic or harmonic behavior with noise-contaminated data, with 10 percent noise density. The comparison between this algorithm and Wolf's method showed relatively less computation time, up to 80 percent, to detect chaos with reasonable accuracy.

Chaotic behavior in bi-stable energy harvesters severely reduces the harvested energy. Besides reducing the energy extracted, this behavior makes the interface circuits' design and production complicated and costly. In this study, chaos control in bi-stable energy harvesters has been investigated. A controller with delayed feedback control has been added to the bi-stable energy harvester to eliminate chaos. Then, the stability range of the control gain is calculated by using the Poincare section. Also, the effect of the main harvesting parameters on the control system stability has been studied. The controlled bi-stable energy harvester's numerical simulation response shows that chaotic behavior is well converted to periodic behavior by the controller. The energy balance diagram shows that the controlled harvester can recover the consumed energy in the actuator in a relatively short time. A bi-stable energy harvester with a chaotic controller has improved in energy and output power compared to a bi-stable harvester without a controller. Changing the control gain, the cross-time in which the harvested energy of the controlled harvester passes the harvested energy by the uncontrolled one is optimized to its minimum possible amount.

Medlar (Mespilus germanica) is widely cultivated in northern Iran and used as an edible fruit as well as home remedies. Short storage life of medlar fruit and its high susceptibility to weight loss and browning are the main limiting factors for its marketability. The aim of current work is to study geometrical (extracted from image), physical (texture and color) and chemical (titratable acidity) properties of medlar to determine the maturity and ripening stages. These parameters are of high importance due to their relation with sensorial quality and their effects on ripening level of medlar. The results revealed that none of the factors mensioned above were stable during the experiment. Result indicated that the lightness (L*), titratable acidity, firmness, h* and ripening index (RPI) decreased during medlar cold storage; while redness (a*), yellowness (b*), and C* values, total soluble solids and pH of medlar increased during this period. The use of the RPI made it possible to characterize three ripening stages (Fresh Medlar (FM), Ripe Medlar (RM), and OverRipe Medlar (ORM)) during the storage period of medlar. The results also showed that there was a significant relationship between ripeness stage and geometrical properties of medlar.

The crucial sensory characteristic of fruits is appearance that impacts their market value, the consumer’s preference and choice (Afsharnia et al., 2017). The task of fruit grading is vital in the packaging industry because there is a great demand for high quality fruits in the market (Liming and Yanchao 2010). Optical sensors have been used for grading, sorting, and fruit quality detection of different crops (Mohammadi et al., 2015). Today, in various agricultural commodity grading systems, computer vision has become an alternative to visual inspection being objective, consistent, rapid, and economical (Chai et al., 2014). Color is the major attribute to assess quality of agricultural products more than any other single factor (Moallem et al., 2017). It represents the degree of maturity, sugar content, acidity, and taste. For instance, in fresh fruit market such as apples and peaches, darker red color represents higher quality fruit than does light red (Cardenas-Perez et al., 2017). Computer vision is a non-destructive method that can be used for inspection and has found to be applicable in both the food industry and precision agriculture, including the inspection and grading of fruits and vegetables (Wan et al., 2018). This paper proposes an automatic and effective hawthorn fruit grading system based on computer vision-based algorithm. Blasco et al. (2008) developed a computer visionbased machine for detecting and removing unwanted material and sorting the pomegranate arils by color. Liming and Yanchao (2009) developed an automated strawberry grading system using image processing technique and graded the strawberry adopting one or two or three indices among shape, color and size. Okamoto and Lee (2009) developed an image processing method to detect green citrus fruit in individual trees to apply for crop yield estimation at a much earlier stage of growth (Mohammadi et al., 2015).

Grading of hawthorn fruits into three quality grades (A, B and C) was conducted by image analysis technique. Physicochemical and geometrical properties of fruits were determined to compare the results of image analysis and visual classification. Color quality parameters (L∗,a∗,b∗,c∗,h∗,∆E) geometrical parameters, weight loss, firmness, total soluble solid (TSS), pH, treatable acidity (TA) and ripening index (RPI) were the measured factors. TSS content was directly measured from the obtained juice using a refractometer. From the same juice the titratable acidity (TA) was determined. The hawthorn firmness was measured by means of a penetration test using a Texturometer Analyzer. In this study, a machine vision algorithm was developed to capture the images of the hawthorn samples, and then it extracted the feature color value to classify quality grade of the hawthorn fruits. For this work RGB images were captured with a resolution of 1936 × 1288 pixels and stored on the computer in TIFF format. Different color spaces have been compared in previous works in which it was concluded that the CIELab space is the most appropriate for the measurement of fruit color. From each image, squares from the equatorial area of the fruit were cropped, trying to obtain the greatest possible area but avoiding areas with excessively bright pixels. For the calibration process and image analysis, conversions were performed by using the color space converter plugin for the public domain image processing application ImageJ software. Next, the values of chroma (C*) and hue angle (h*) were also calculated. Principal component analysis (PCA) was used to analyze the dataset obtained from the study of the hawthorn storage. The first set of 200 hawthorns was arranged in a matrix of 14 variables (TSS ،TA ،F ،WL ،φ،Dg ،MDL ، RPI ، L∗ ،a∗،b∗ ،∆E ، C∗ and h∗) ×200 averaged measurements. This matrix was used to calculate the Pearson correlation matrix, variable contributions, factorial loadings, eigenvalues, and percentage of variance of the principal components related to the original variables. Later, a second model was built including only the color variables and was used to classify the hawthorns into quality grade.

Principal component analysis was used to evaluate the correlation between variables. A first correlation was performed between physicochemical and color parameters and variables correlated correctly between each other except for L*, but both described the samples variability with 94.2% reliability. Using only color parameters, the samples were described accurately with 97.4% reliability. Two classifiers based on linear (LDA) and quadratic discriminant analysis (QDA) were used to assess the applicability of vision system. Color parameters obtained by means of CVS under laboratory conditions provided an adequate classification of the quality grade of hawthorn fruits and showed a good correlation with the flesh physicochemical parameters measured. LDA and QDA were capable of classifying hawthorn in their correct quality grade with 99% and 99.5% accuracy, respectively.

The current study used image analysis technique to classify hawthorn fruits into three commercially quality grade (A, B and C). The written algorithm captured an image, eliminated the noises, obtained binary image, removed the noise, and ultimately extracted the color features. This demonstrates that it is possible to create a reliable and objective method for the non-destructive evaluation of quality grade. The selection of variables performed using PCA and the classification model built by means of LDA and QDA allowed adequate classification of the hawthorn according to quality grade using only L∗ ،a∗،b∗ ،∆E ، C∗ and h∗. Thus, it was concluded that external color features of hawthorn fruits can be potentially used to classify the fruits with a proper probability.

Recent research has focused on insecticidal property of essential oil plants in biological control of insects. Controlled release by nanoencapsulated essential oil seems to be the best choice for increasing the efficiency and minimization of environmental damage. In this work, efficiency of nanoencapsulated essential oil of Artemisia sieberi Besser was tested on repellent activity of Plutella xylostella L.. Several concentrations were prepared and then third instars larvae were introduced into each treatment. Then, repellent activity was determined after 1, 3, 6, 12 and 24 h from commencement of exposure. Results showed that at 1.9 ppm the nanocapule of Artemisia oil was shown here to possess more repellent activity (80%) to P. xylustella compered to Artemisia oil (62%) before formulation after 24h. The repellent activity varied with application method and concentrations and exposure time. The results showed higher repellent rates in nanocapsule than in essential oil due to controlled-release formulations allowing smaller quantities of essential oil to be used more effectively over a given time interval. The reasons for nanocapsulating the essential oil have been to improve its stability to reduce side effects or to reduce dosing frequency and total dosing amount, to obtain better repellent activity, and for sustained (long-lasting) release. Therefore the nanocapsulation of A. sibeiri might provide a new method for the management of P. xylostella.