javad tarighi

Solar cells, also known as photovoltaic (PV) cells, are electrical devices that convert the energy from the sun's rays into electrical energy. Solar cells operate by converting sunlight into electricity as long as there is sunlight available. One of the key advantages of solar cells is their ability to efficiently convert the abundant and free radiant energy from the sun into electrical energy without any waste. Unlike other non-renewable energy production methods such as fossil fuels, hydroelectric, and nuclear power plants, solar cells do not pollute the environment. It is crucial for solar cells to maintain their efficiency even in low radiation levels when sunlight is present. The development of grid-connected photovoltaic power plants has garnered significant attention due to reduced losses associated with proximity to the point of consumption, thereby minimizing the need for transmission from the power plant to the consumer. These power plants integrated into the distribution network offer numerous benefits, including enhancing line capacity, transformer utilization, voltage profile improvement, load distribution leveling, and enhancing power quality. This article investigates the quantitative and qualitative effects of operating a 50 kW grid-connected power plant located in the cultural and sports complex of Nikian Abhar. Improvement of the voltage profile up to 4.2%, reduction of power losses during peak hours up to 37% and reduction of energy losses up to 25.2 kilowatt-hour per day are among the results of the investigation.

Aside from energy production, biogas technology also contributes to mitigating environmental impacts. One of the key advantages of biogas is that it does not compete with human food sources. However, the main limiting factors include the digestibility of hemicellulose and cellulose in biomass, along with challenges related to lignin, cellulose crystallinity, and particle size. Lignin, abundant in softwoods, poses a complex structure, and its isolation remains a challenging issue that researchers are endeavoring to address. In the realm of enhancing productivity and achieving cost savings in biogas production, various measures have been implemented, with pretreatment emerging as a viable approach. Pretreatment involving physical, chemical, or biological methods can be applied to the digestion process. At this juncture, the emphasis should be on utilizing efficient and cost-effective methods and materials. Shredding biomass reduces its crystallinity by increasing the biodegradable surface area. Acidic pretreatment, avoided due to its cost and negative environmental impact, contrasts with the environmentally friendly and low energy consumption associated with biological pretreatments. Among the alkaline pretreatments, NaOH plays a significant role. Strong alkaline pretreatment is recommended for small digesters, while medium acid pretreatment is more suitable for larger digesters. The utilization of zero-valent iron nanoparticles is deemed as the most promising approach for enhancing biogas production. Furthermore, carbon-based nanoparticles have demonstrated a significant capability to enhance biogas production through electron transmission., In order to make biogas production affordable and reduce greenhouse gas emissions, carbon dioxide and hydrogen produced from biogas were used in industrial applications.

This study has been conducted on the vital role of life cycle assessment (LCA) as a comprehensive method to evaluate the sustainability of biodiesel power generation, with a case focus on the Moghan region. Life cycle assessment covers all stages of biodiesel's life cycle, including production, distribution, and use, and provides a complete view of its environmental impacts. This study uses methods such as cradle-to-grave analysis, carbon footprint calculation, and various impact assessments to measure ecological outcomes. This article examines the distinctive features of the Moghan region's local agricultural practices, biodiesel production methods from rapeseed as the dominant oil crop in the region, and energy consumption trends. The results show that the use of fuel, plastic, and gas in rapeseed cultivation has the most intermediate effects (about 5-25% higher than other inputs) in the Moghan region. In addition, electricity consumption significantly (about 200-300% more than other inputs) affects the intermediate effects during the rapeseed oil extraction process in the Moghan region. Evaluations show that inputs of water (on average about 300, 350, 250, and 400% more than oil, sodium hydroxide, hydrochloric acid, and methanol) and electricity (on average about 150, 170, 120, and 200% more than oil, sodium hydroxide, hydrochloric acid, and methanol) can contribute the most to the environmental impacts in the biodiesel production stage from rapeseed oil in the biodiesel region. In addition, this study identifies that the biodiesel fuel itself has the greatest effect on the intermediate indicators of electricity production from canola-derived biodiesel.

Walnut is an important economic and commercial product all over the world. The reflected light spectrum can be one of the key factors in determining the ripening time of the fruit and it depends on the content of the chemical compounds of the fruit and its skin. Crunchyness and easy peeling are the main features that affect the level of satisfaction of walnut consumers. The complexity of the reflectance spectrum of food makes it difficult to analyze them with conventional analytical techniques such as gas chromatography. However, sensory analysis by experts is a costly process and requires trained people who can only work for a relatively short period of time. A near-infrared spectrometer can detect the spectrum of reflected light by estimating its concentration or determining some of its inherent properties.The quality assessment of agricultural products includes two main methods, quality grading systems based on the external characteristics of agricultural products and quality grading systems based on internal quality assessment, which has gained outstanding points in recent years. In the meantime, several methods have been invented so far for the qualitative grading of agricultural products based on the assessment of their internal properties in a non-destructive way, and only some of them have been able to meet the above conditions and have been justified in terms of technical and industrial aspects. To be meanwhile, spectrometry can be highly efficient in determining the quality of cultivars. Spectroscopy is a type of system that has a different structure and approach from other methods (image processing, neural network, etc.) and can perform classification and determination of digit quality.With increasing expectations for food products with high quality and safety standards, the need for accurate, fast and targeted determination of the characteristics of food products is now necessary. Because manual methods do not have automaticcontrol, they are very tiring, difficult and expensive, and they are easily affected by environmental factors. Today, spectroscopic systems are non-destructive and cost-effective and are ideally used for routine inspections and quality assurance in the food industry and related products. This technology allows inspection works to be carried out using wavelength data analysis techniques and is a non-destructive method for measuring quality parameters. In this research, the ripening time of walnuts was investigated using spectrometry and chemometrics methods.

In each treatment period (in total 5 periods were considered and the intervals of periods were determined as one week), unripe walnut samples in addition to ripe samples (in the last period) were taken from one of the orchards around Ardabil (located in Shahrivar village) was prepared, tested and data collected.A spectroradiometer model PS-100 (Apogee Instruments, INC., Logan, UT, USA) was used to acquire the spectrum of the samples. This spectroradiometer is very small, light, portable, has a single-wavelength sputtering type with a resolution of 1 nm and a linear silicon CCD array detector with 2048 pixels that covers the spectral range of 250-1150 nm (Vis/NIR) well. Also, there is the ability to connect the optical fibre to the PS-100 spectroradiometer and transfer the data to the computer with the purpose of displaying and storing the acquired spectra in the Spectra Wiz software through the USB port. With the aim of creating optimal light in contrast mode measurements, an OPTC (Halogen Light Source) model halogen-tungsten light source, which can be connected to an optical fibre, was used. This light source has three output powers of 10, 20, and 30 watts, which were used in this research. Also, a two-branch optical fibre probe model (Apogee Instruments, INC., Logan, Utah, USA), which includes 7 parallel optical fibres with a diameter of 400 micrometres, was used in counter-mode measurements. After providing the necessary equipment, the optimal spectroscopic arrangement was designed and implemented in order to facilitate the experiments and minimize the effect of environmental factors during the spectroscopic process, which is shown in Figure 1.

The average absorption spectra of Vis/NIR absorption spectra for different treatments in the range of 680-970 nm are presented in Figure 1.Environmental factors (light and heat) as well as the spectrometer's expression quality cause disturbances in the initial and final wavelengths of the spectra, so some of these wavelengths are removed from the data set. And as it is clear in Figure 1, the samples had an almost similar trend; this may be affected by the colour of the samples. According to Figure 1, there are two distinct peaks for the spectra and it is that the peaks appeared around the wavelength of 680 and 970 nm. It can also be seen in Figure 1 that the amount of absorption of ripe walnuts is higher compared to other periods, which can be due to the difference in the content and texture of the product.Based on the PCA analysis results presented in Figure 2, the first principal component (PC-1) describes 94% and the second principal component (PC-2) describes 5% of the variance of the tested samples. As a result, the first two principal components together express 99% of the data. Considering that it is possible that the degree of correlation between the properties of different samples during the tests, due to various reasons such as technical problems of the equipment, data collection, incorrect sampling, etc., in some samples, inappropriate or so-called outliers.The values of R2 and RMSE for calibration and validation sets of different regression models (PLS) with raw and processed data are presented in Figure 3, which is equal to 0.98. The results show that the spectra are able to detect the ripening time of walnuts with high accuracy. Khodabakhshian et al investigated the potential of visible and infrared spectroscopy to classify the ripening stage and predict the quality traits of pomegranate varieties including SSC and TA. Among the methods of centring, Savitzky-Golay smoothing, median filter, standard normal variable, incremental spread correction (MSC) and differentiation with first derivative and second derivative, the use of incremental spread correction (MSC) has the highest accuracy in identifying pomegranate quality parameters. followed Zhang and colleagues (Zhang et al, 2018) in estimating the SSC of red Fuji apple using near-infrared spectroscopy to reduce noises using the functions of additive scatter correction (MSC) and standard normal distribution (SNV) and reported that the additive scatter correction method (MSC) compared to the standard normal distribution (SNV) will result in a more accurate estimate of the SSC value. Kim et al. estimated the SSC of oriental melon using near-infrared spectroscopy among different pre-processing methods including Savitzky-Golay smoothing, normalization with maximum and minimum, stable normalization, standardization, stable normal variable, distribution Standard normal (SNV) and incremental spread correction (MSC) reported that the best result was obtained with a standard normal distribution (SNV). Although considering the different nature of the samples, measurement methods and equipment, and other conditions affecting the spectral properties of the product, it is better not to compare the data obtained from different researches with each other.

In recent years, wind energy has received a lot of attention and many advances have been made in changing wind energy to electrical energy and mechanical energy. Wind energy is sustainable energy that plays an important role in increasing the energy production of countries and international policies against climate change. Most countries around the world are now facing environmental problems due to the consumption of fossil fuels, so they have turned to clean energy. For this reason, one of the best and most economical methods available is to use wind power and wind turbines. The development of this industry is possible when it is compared to other sources of economic energy, and considering the cost-free production of this energy, it is of course economical. Being economical means balancing the costs of investing and getting energy through it. The most important parameter influencing the construction of a wind turbine is the selection of the best airfoil. A wind turbine is a device that converts wind energy into electrical energy. There are two types of wind turbines available: horizontal axis wind turbine (HAWT) and vertical axis wind turbine (VAWT). HAWT is very useful in generating electricity but it also has problems, for example it needs YAW mechanism, regular maintenance, additional cost in strengthening the tower structure, maximizing the rotor diameter, number of rotor blades, loud noise, wind direction it is suitable and dangerous for migratory birds. The ability to control wind flow in order to form the desired change is of great technological and practical importance. More than any other topic in fluid mechanics, it is now pursued by researchers and engineers to come up with methods for better efficiency and lower flow control. Wind characteristics in urban areas are significantly affected by the roughness of urban areas. It creates more complex properties for wind that the separation of wind flow is influenced by buildings in response to strong multidimensional winds in urban environments. Due to the disadvantages of HAWT and VAWT wind turbines and wind characteristics in urban areas, researchers have started to build cross-axis wind turbines. The CAWT wind turbine is more efficient in terms of wind turbine performance in different directions of urban areas. It can receive wind energy in horizontal and vertical directions. CAWT has the ability to overcome the disadvantages of any type of wind turbine and because of CAWT's ability to receive wind energy regardless of wind direction, it is a good alternative to conventional VAWT wind turbines in urban areas, thus increasing the performance of wind turbines.

The initial design of the CAWT wind turbine consists of 3 vertical blades and 6 straight horizontal blades as shown in Figure 3. The CAWT wind turbine consists of a support frame, a turbine rotor assembly mounted on a support frame and rotating on its vertical axis. To change the nature of kinetic energy from the movement of the turbine rotor to electrical energy and mechanical energy, an electric generator is connected to the turbine assembly. In this study, the CAWT wind turbine with 3 vertical shaft blades NACA 0018 and 3 horizontal shaft blades NACA 4412 which are connected to each other through special connections were evaluated. The advantage of CAWT is that it can work with the airflow on both sides through the vertical axis airfoil and from below and above the turbine through the horizontal axis airfoil. The horizontal axis blades act as the CAWT radial arms and attach the hinges to the vertical blades. Joints are used to pair horizontal blades and vertical airfoil blades. Horizontal wind can be picked up from all directions by vertical blades. The vertical wind flow from the bottom of the turbine can be received with horizontal blades, which improves the spontaneous ability to start the turbine and create aerobic force. This force reduces the bearing friction in the generator and thus increases the life of the wind turbine. In urban areas, wind currents are complex due to roughness and tall buildings, which makes it difficult to separate wind currents from each other. CAWT is superior to other wind turbines in this situation and receives wind currents from both sides. These wind conditions that are not predictable, especially in urban areas, require a special wind turbine that uses the potential of wind power. In this study, SolidWorks and Ansys Fluent software were used. First, the turbine was designed in SolidWorks software and Ansis Fluent software was used to analyze the wind flow. The first step to design or simulate a wind turbine is to choose wind conditions such as wind speed, direction and thickness, for which meteorological information from Mazandaran province was used. In this research, we intend to work on the full router model and obtain the effects of wind speed on it, we will obtain the production power and production torque of each region. According to the two formulas of output power and torque, the output power and torque of the turbine was considered in four wind stations, including Sari, Dasht-e Naz, Bandar Amirabad and Gulogah, where the average wind speed of the previous year was set for software input.

In this study, a 5 kW wind turbine with two types of airfoils in accordance with the climatic conditions of Mazandaran province was simulated using Ansys Fluent software. The steps were done in such a way that according to the meteorological data of four stations in Sari, Dasht-e Naz, Amirabad and Gulogah, the average annual wind speed in these areas was determined. The turbine was designed according to the dimensions specified in the SolidWorks software environment. The output of SolidWorks software is entered into Ansys Fluent software to solve the continuity and momentum equations for the control volume by applying the considered boundary conditions. The results in Ansys Fluent software show the force equal to 2089 (Newton) and the torque equal to 592.9 (radian joule). As a result, the power of the turbine is equal to 12.415 (kW). In this part, the result is the turbine production capacity of this research is about 2.5 times more than the vertical axis turbine, which has the same characteristics as the wind turbine of this research.

Fruit juices are an important part of modern diets in many countries and one of the best drinks. Fruit juices provide a significant portion of the body's needs for minerals and vitamins and are recommended by nutritionists. By definition, the liquid extracted from fruit that has not been fermented and contains major processes such as preprocessing, extraction of fruit extracts, and post-pressure treatments is called fruit juice. Consumption of fruit juices has increased significantly over the past years and is growing significantly because consumers are interested in healthy and ready-to-eat products. The fruit juice industry is one of the industries that play an important role in the food industry and providing a high-quality product is important to achieve effective competition. Watermelon (Citrullus lanatus) belongs to the family Cucurbitaceae. This plant grows in more than 96 countries. China leads in 2015 with 70.3% of total world watermelon production. Other leading countries are Turkey, Iran, Brazil, the United States and Egypt. Watermelon fruit produces 55.3% water, 31.5% shell and 10.4% pulp. Carotenoids such as lycopene and β-carotene indicate the red and orange colours of watermelon, respectively. Watermelon sweetness is mainly due to a combination of sucrose, glucose and fructose. Sucrose and glucose make up 20-40% and fructose 30-50% of the total sugars of ripe watermelon. Watermelon juice has amazing and dense amounts of nutrients. One cup of this drink has high amounts of vitamin C and vitamin A, which cover 30% and 25% of your daily requirement for these nutrients, respectively. This drink also has moderate amounts of potassium, dietary fibre, calcium, iron and 1.5 grams of protein. Most importantly, a cup of this water contains only 70 calories but is rich in antioxidants and active ingredients such as lycopene, beta-carotene, amino acids and flavonoids. Apart from their role in the human diet, fruits are prone to spoilage due to high humidity. Post-harvest spoilage losses can be caused by pests that occur on the farm during harvesting, storage or distribution. Post-harvest mortality has been reported at 20 to 50 per cent in developing countries. If these products are processed prematurely, these losses can be avoided. The high cost and lack of efficient tools for crop processing, poor marketing and transportation system, as well as fruit perishability, contribute to more post-harvest losses. The lack of local and simple mechanical tools for processing fruit into fruit juice often leads to limited use of the fruit and consequently more losses after harvest due to rot. In order to reduce fruit losses, fruit juice extraction is a suitable option. Traditionally prepared fresh fruit juices, although pleasant and palatable and containing the vitamins and minerals found in the original fruits, can in most cases act as potential sources of contamination due to non-compliance with health standards in their preparation. This contamination may occur before or after fruit juice extraction. So far, many researchers have worked on the design and optimization of fruit juicers for various fruits and agricultural products.On the one hand, mechanization of the watermelon water production process is necessary to further improve the health of the production process. On the other hand, today, in addition to traditional methods, there are various devices for extracting different fruit juices. Most of these devices are versatile and are used for a variety of fruits. It is clear that these multipurpose devices, due to their different physical, mechanical and rheological properties, can not provide an effective fruit juicing process for several types of fruit. Therefore, to design an effective fruit juicer, accurate information about the watermelon juice extraction process is required. The aim of this study was to determine the effects of some factors affecting the kinetics of watermelon water extraction.

In order to perform the experiments, the product prepared from the local market of Karaj city was transferred to the laboratory. The experiments were performed in the laboratory of the Faculty of Agricultural Machinery, University of Tehran, located in Karaj. In order to perform the experiment, the skin of the watermelon crop was manually separated from its mantle. Using PVC cylindrical tubes with a diameter of 50 mm, the watermelon was divided into cylindrical parts and six-centimetre pieces were created. In order to reduce the error in the amount of extracted fruit juice and also to reduce the effect of the crop on the amount, parts of the product that had little core were used. The watermelon crop was divided into six-centimetre, two-centimetre and two-centimetre layers for testing. Then, the mass weight of the prepared product was measured before each experiment by a digital scale with an accuracy of 0.01. Necessary pressure for dehydration of the product was created by a multifunctional material strength test machine (-500-Hi SE, Farvardin Azma Tajhiz, Iran). The device was connected to a computer, and the test settings were applied through software. A cylinder with a height of 150 mm made of stainless steel with an inner diameter of 57 mm was used as a cylinder. A piston with a cross-sectional area of 57 mm in diameter was used to apply the pressure created by the multi-purpose test machine to the product mass. To record the force and displacement data simultaneously, a 500 kg load cell (type S, Zemic, China) was used to connect the piston to the jaw of the multifunction test device.

According to the analysis of variance tables, the effect of three variables of maximum load, the number of layers and loading speed as independent variables on the model of predicting fruit juice mass percentage, constant coefficients of force-displacement equations and moment juice-displacement mass equation was significant at 1% level. However, in all cases the P-value associated with each of the independent input variables or their interactions alone was not significant; but the significance of all forecasting models shows their high ability to evaluate data. Also, in most cases, the high explanation coefficient of the models indicates the high accuracy of the models and the proximity of the real value and prediction. The results show that the lowest percentage of extracted fruit juice is 5.95% with input variables (loading rate of 20 mm/min, maximum loading of 160 kg and single layer) and the highest percentage of extracted fruit juice with 95.36% with input variables (loading rate). 10 mm / min, maximum load of 400 kg and three layers); Therefore, in order to extract a high percentage of fruit juice, the loading rate must be reduced and the maximum loading and the number of layers must be increased.

The use of renewable energy sources is important today due to the reduction of fossil fuel sources and the increase in environmental pollution. Biodiesel is one of the types of renewable energies. By 2020, 20% of the fuel used is from renewable sources, Biodiesel is one of the most important strategies to complete these choices and achieve the goal. Biodiesel as biofuel can be used in diesel engines in combination with pure diesel and thus improves combustion conditions and reduces emissions. Biodiesel is produced from different biomass in different ways and processes, this depends on the potential of the area in question and the availability of bio-resources. On the other hand, the technology used in biodiesel production is also important. Given the technology and biomaterials used to produce biodiesel, economic cost and production efficiency will be achieved. Therefore, in the face of increasing demand for biodiesel production, it is important to provide a suitable way to commercialize the biodiesel production process. In this regard, different methods of biodiesel production from different sources are investigated in this research, in order to find the appropriate method for achieving a biodiesel production process. Based on the results of this study, biodiesel production depends on the conditions and availability of primary biofuels, but in general biodiesel production from non-food sources with alkali catalysts are of commercial importance in the process of trans-esterification; this method produces high-efficiency biodiesel (about 98%) and is economically superior to other methods.