access deny [1301]
Research field: Research areas of these greenhouses included greenhouse control and automation systems, water and en
Expert: Akbar Kolivand
Phone: +98-021-48292487
Address: Faculty of Agriculture, Tarbiat Modares University 14115-336
Research field: The research areas of this laboratory is designing and manufacturing of electronic circuits and auto
Expert: Akbar Kolivand
Phone: +98-021-48292487
Address: Faculty of Agriculture, Tarbiat Modares University 14115-336 , First Floor, Room Nu. 136
access deny [1026]
see more details with sufficient sunlight, temperature, and humidity. Better growth conditions in the greenhouses are mainly achieved by maintaining the optimum indoor temperature compared to the outdoor temperature of the greenhouse. The objective of this study is design, construction construction Subject Category: Disciplines, Occupations and Industriessee more details and evaluation of a fuzzy control system for a research greenhouse with capability of measuring, control and monitoring of greenhouse environmental conditions. Greenhouses control variables are air temperature air temperature Subject Category: Properties
Greenhouse is an environment where variables such as: climate, nutritional and biological conditions can be controlled. Therefore, the greenhouse allows horticultural crops to grow in the off-season and also affect plant growth to achieve optimal conditions for different stages of crop growth (Janoudi., 1993). The purpose of a greenhouse construction is to achieve the maximum amount of a product with the highest quality and minimum cost. Multiple factors and relationships inside the greenhouse have made it a complex system in which energy, mass transfer and genetic factors. Greenhouse production is affected by various variables, such as changes in environmental conditions (temperature, humidity, carbon dioxide and plant photosynthesis), pla
Timing belt rupture, which can develop quickly and cause severe harm to various engine components, usually occurs unexpectedly and without prior warning signs. Due to the rapid occurrence of timing belt rupture, fault diagnosis strategies are not indeed efficient. In this paper, a vibration-based intelligent method has been proposed to predict the remaining useful life (RUL) of the timing belt using data mining techniques and multi-layer perceptron neural network (MLP-NN). To achieve this goal, two categories of experimental tests were designed and carried out on the timing belt, namely, fault thresholding (FT) and accelerated life (AL) tests. FT test was performed by comparing the defect-free belt vibration signals with those of a faulty b
Introduction Immature birds, like humans and many animals, pass through the puberty period to sexual maturity that is accompanied by sound changes and after the sexual maturity, the sound structure evolves. The puberty period is one of the most important periods in the breeder chicken farms. Because the feeding of roosters at this age can delay or accelerate the time of sexual maturity. On the other hand, the diagnosis of mature roosters to mating with chickens increases egg production in early adulthood. Sexual maturity is a summary of the morphological and physiological changes its peak in the roosters from the age of 16 to 24 weeks. In female birds, the beginning of the first laying is considered to be sexual maturity, while the exact ti
Due to the lack of drinking water people have been forced to obtain fresh and renewable water sources. For this reason, desalination systems are being developed around the world. Ultrasound technology is one of the most recent technologies in the desalination industry which improves the evaporation and distillation processes by increasing the mass and heat transfer that causes a reduction in energy consumption. This technology can help to maintain the health and safety of people because of avoiding the use of chemical material. In this study, an ultrasonic desalting system was evaluated in terms of salinity and the amount of produced water through response surface methodology (RSM). It was found that the salinity of incoming water had the
An automatic steering system based on fuzzy logic was developed aiming at navigating a JD955 combine harvester. This system included electro-hydraulic components to steer the harvester using electrical signals, a machine vision system to determine the lateral and angular deviations of the harvester, a fuzzy control system to generate correction signals and a safety system for the steering circuit. Results of evaluation showed that the image processing system was able to detect a specific path accurately in 98% of the cases. Root Mean Square (RMS) of deviations from the path was used to evaluate the system performance. Evaluation of the system was performed on straight-line and curved paths at travel speeds of 1 and 2 m/s and path negotiati
see more details have a converse effect on a production of crops. Therefore, in these regions, it is necessary to reduce the temperature inside the greenhouse. Since the design of the cooling system is highly dependent on environmental conditions, it is difficult to develop an appropriate system that provides local climate conditions for product growth. Therefore, in this research, the performance of fan-pad cooling system was studied in different climatic conditions. For this purpose, the greenhouse environment was first modeled using TRNSYS software. After verifying the model with experimental results, the system's ability to cool the greenhouse and system performance was evaluated relative to the parameters of air velocity velocity Subje
Sexing is a difficult task for most birds (especially ornamental birds) involving expensive, state-of-the-art equipm ent and experiments. An intelligent fowl sexing system was developed based on data mining methods to distinguish hen from cock hatchlings. The vocalization of one-day-old hatchlings was captured by a microphone and a sound card. To obtain more accurate inf ormation from the recordings, time-domain sound signals were converted into the frequency domain and the time-frequency domain using Fourier transform and discrete wavelet transform, respectively. During data-mining from signals of these three domains, 25 statistical features were extracted. The Improved Distance Evaluation (IDE) method was used to select the best features
The effect of voltage gradient, pH and S/L ratio during ohmic heating up to 90 ?C on the heating rate, system performance coefficients (SPCs), yield, and quality of pectin was investigated. The results showed that the rate of heating was increased with increasing of voltage gradient (from 5 to 30 V/cm) and decreased with decreasing of pH (from 4 to 1.5). With increasing of voltage gradient and decreasing of pH and S/L ratio, SPC was increased and the highest SPC was 84.4%. The yield of pectin was increased sharply from 1.17 to 10.69 g/100 g d.m. by decreasing of pH from 4 to 1.5. Finally, the highest SPC and yield of pectin with good quality (high DE and galacturonic acid) were obtained at the voltage gradient of 30 V/cm, pH of 1.5 and
Industrialization and growth in the world's population have increased the demand for fresh water. Solar desalination systems are energy consuming and therefore using solar stills in the remote locations is more feasible and affordable. In the present study, a solar distillation system integrated with a solar parabolic trough concentrator and a vacuum-type heat exchanger with falling film technique has been developed and experimentally evaluated during five sunny days in October 2015 between 10?am to 2.30?pm. During the evaluation period, the environmental parameters of solar radiation, air temperature, and wind speed were recorded in every 15?min. Then, the effect of these environmental parameters on the daily productivity of the distillati
Ohmic heating is defined as a process which alternating electric current is passed through food with the primary purpose of heating it due to the electrical resistance and can be specially applied as an alternative heating method. In this research, Aloe vera gel concentrates having 0.5-2% soluble solids were ohmically heated up to 60 C by using four different voltage gradients (30–60 V/cm). The dependence of electrical conductivity on temperature, voltage gradient and concentration were obtained. Results indicated that there was a linear relationship between temperature and electrical conductivity. The range of the electrical conductivity was 0.45 to1. 20 S/m, which was dependent on the concentration and voltage gradient, although the eff
Food security, defined as the maximization of self-confidence and social justice for all of the community residents to obtain a safe, culturally acceptable and nutritionally adequate diet through a sustainable food system (Hamm and Bellows, 2003), is one of contemporary major challenges mainly under the effect of climate change (Franzluebbers, 2013). While the world population is increasing, crop models are important tools to develop, implement and maintain food security (Mahajan et al., 2014).
Fertility is an important trait in poultry industry so that any reduction in fertility resulted in a huge economic loss by rising incubation costs. In this study, dielectric constant and loss factor of eggs were used as a non-destructive, cheap, and precise method to identify dead embryos and infertile eggs, during incubation. For this purpose, artificial neural network (ANN) and support vector machine (SVM) classifiers were used. The result indicated that SVMs truly identified dead embryos with 100% accuracy at day 18 of incubation before hatching. In addition, SVM could also correctly identify un-hatching eggs, including dead embryos and infertile eggs with 92.31% accuracy at the 5th day. Neural network correctly classified un-hatching eg
Biophysical properties of agricultural materials are important in designing of processing machines. In this study, some physical properties of tomato (Solanum lycopersicum) fruits were determined and their mutual relationships were studied. Dimensions (major diameter, minor diameter, and length), mass, volume, fresh and dry matter weight, as well as rupture point under uniaxial loading were measured. Other properties; including Poisson's ratio, modulus of elasticity, energy for rupture, density, arithmetic mean diameter, geometric mean diameter, diameter of equivalent volume sphere, and sphericity were calculated accordingly. Statistical analysis of the data indicated significant correlations between the rupture force and fresh weight, volu
The present study presents an intelligent procedure for simultaneous diagnosis Avian Newcastle Disease Virus, Infection Bronchitis Virus as well as Influenza through heart sound signals. To follow the aim, the sample chickens were divided into four groups. The first group was taken as the control. The second, third and fourth groups were respectively infected with Newcastle Disease Virus, Infection Bronchitis as well as Avian Influenza. The time domain signals were transferred to the frequency and time-frequency domain using Fast Fourier and Discrete Wavelet Transforms. In data mining stage, 25 statistical features were extracted from three domains and the most appropriate features selected, using Improved Distance Evaluation (IDE) method.
Sexing is a difficult task for most birds (especially ornamental birds) involving expensive, state-of-the-art equipment and experiments. An intelligent fowl sexing system was developed based on data mining methods to distinguish hen from cock hatchlings. The vocalization of one-day-old hatchlings was captured by a microphone and a sound card. To obtain more accurate information from the recordings, time-domain sound signals were converted into the frequency domain and the time-frequency domain using Fourier transform and discrete wavelet transform, respectively. During data-mining from signals of these three domains, 25 statistical features were extracted. The Improved Distance Evaluation (IDE) method was used to select the best features an