Renewable Energy

This paper reports the design, implementation and testing of an indirect solar potato dryer. Indirect solar drying is the new technique of product drying. It is very efficient method than the direct type of solar drying. In this method the atmospheric air is heated in flat plate collector. This hot air then flow in the drying cabinet or drying chamber where potatoes slides are stored. Therefore moisture from the potatoes slides may lost by convection and diffusion. This method of drying is used to avoid direct exposing to the solar radiation. This method mainly reduces the disadvantages of direct solar drying. The experimental set up used for testing the performance of an indirect solar food dryer and determining the influence of various drying methods on the drying behavior of fresh potatoes slides. Evaluation of the dryer was centered on the moisture content reduction and temperature variations. 2 kg of fresh potatoes slides was used for evaluation. Temperatures of the drying chamber (drying cabinet), solar collector and ambient air were taken daily using digital sensors on an hourly basis from 9:00 am to 5:00 pm. Moisture content was taken at the beginning and at the end of each drying day. The test results gave temperature above 65 oC in the flat plate collector (solar collector), 50 oC in the drying cabinet, and the moisture content of 2 kg of fresh potatoes slides reduced to about 66.1 % in five days of drying.

Nowadays, tractor is one of the most important power sources in agriculture. Replacement of tractor is one of the most important decisions that should be made by farmer. Proper performance in this case can lead to timely, high quality farm operations which in turns results in considerable decrease in product expenditures and also more income. The current study was performed in order to determine economically optimum life of MF285 tractors in Debal Khazaei Agro-Industry Co. in Khuzestan province of Iran. Moreover, listed price of tractor, annual depreciation and Internal Rate of Return in the study period were calculated. Then, these items accompanied by their repair and maintenance cost were used to determine their economic life. Finally, replacement time for the study tractors was obtained equal as 6981 hours. These hours of operation are performed in about 14 years and thus the tractor should be replaced.

In a dynamic of protection of the environment and sustainable development, solar energy is one of the essential solutions to the energy problems of developing countries and to limiting greenhouse gas emissions. In this work, we compare the energy productivities of photovoltaic installations in four cities of two countries (Morocco and Burkina Faso). Government energy policies in both countries place a strong emphasis on solar photovoltaics. We then chose to make a detailed evaluation of the performances of the various photovoltaic technologies under various climatic conditions in these countries. PVsyst software is used to model the performance of a photovoltaic solar power plant connected to the 6kWc network (2kWc per technology) using three silicon-based photovoltaic technologies, namely: polycrystalline (pc-Si), monocrystalline (mc-Si) and amorphous (a-Si) in two cities per country. The comparative analysis included annual energy efficiency, performance ratio, annual energy density and system efficiency. From these performances, it can be observed that PV installations with a-Si have the highest energy yields and performance ratios (Er-Rachidia, Ouagadougou and Bobo-Dioulasso), while in Mohammedia, energy efficiency and maximum performance ratio are given by pc-Si technology. The mc-Si installation has the maximum overall efficiency of the system as well as the annual energy density in the cities selected for this study. The production of the city of Mohammedia is validated by the actual production of a 6kWc installation (2kWc per technology) made up of three mini-power plants, one with polycrystalline silicon, one with monocrystalline silicon and the other with amorphous silicon. Comparing the data validates our results.

Vibration technique in a machine condition monitoring provides useful reliable information, bringing significant cost benefits to industry. By comparing the signals of a machine running in normal and faulty conditions, detection of faults like journal-bearing defects is possible. This paper presents an appropriate procedure for the fault detection of main engine journal-bearing based on vibration analysis. The frequency-domain vibration signals of an internal combustion engine (IC engine) with normal and defective main journal-bearings were obtained. The signal processing technique plays one of the important roles for recognizing the journal-bearing fault in the proposed system. In the present research, the data mining method based on feature extraction and selection is proposed. The database is established by the feature vectors of frequency domain signals which are used as input pattern in the training and identification process. The SVM and KNN is proposed to identify and classify the journal-bearing fault conditions in the condition monitoring system. The experimental results verified that the proposed diagnostic procedure has more possibilities and abilities in the fault diagnosis of the main journal-bearing of IC engine.

In this work Mahua oil cake was used to extract the bio oil using fixed bed fast pyrolysis experiments. The effects of three parameters on the pyrolysis efficiency were tested to identify the optimal bio oil production. The parameters are temperature, nitrogen gas flow rate and feed stock particle size. The Response Surface Methodology (RSM), with a Box Behnken Design (BBD), was used for modelling and optimizes the process parameters. The results showed that the second-order polynomial equation explains adequately the non-linear nature of the modelled response. An R2 value of 0.9318 indicates a sufficient adjustment of the model with the experimental data. The optimal conditions found to be at the temperature of 550°C, N2 flow rate of 0.3 lpm and particle size of 4 mm. The yield of bio-oil was obtained 25.90 wt %. In addition the bio oil was characterized by elemental the gas chromatography - mass spectrometry (GC- MS) were analyzed.

Wavelet analysis is one of the most powerful and latest tool in the field of signal processing. It provides the better resolution in time and frequency domain simultaneously. Because of these properties of the wavelet it can be effectively used in EMG signal processing in order to determine the certain changes in amplitude at certain frequencies. At different levels of various mother wavelets we can get the useful resolution component from the EMG signal. In this paper, a single-channel electromyogram acquisition system Biopac MP36 was used to obtain the surface electromyogram signal. Single pair of surface electrodes was used to measure and record the EMG signal on forearm muscles. Then different levels of Daubechies Wavelet family were performed to analyze the EMG signal. We have used root mean square (rms) value of the EMG signal at different level of wavelet coefficients and reconstructed wave. The experimental results shows that rms feature vector provides very good performance for the classification of patterns.

The current work presents a theoretical study of the solar power plant with parabolic trough solar collector, the power generated from the solar power plant was calculated with using the thermal storage system without using such a system then comparison between the two cases. The calculations of the thermal storage system in terms of the size of the thermal tank and the temperature of the heat transfer fluid inside the thermal tank as well as its mass are implemented. The theoretical study are completed at Baghdad city (Long. of 44.25° East and Latit. of 33.19° North). The results were obtained by simulating the solar power station with parabolic troughs for both cases by using the thermal storage system and without it. During this work, some hypotheses were created to facilitate the solution of the system of equations for such plants. It was assumed that the specific heat of the heat transfer fluid in the tank of heat accumulation system was constant, It was calculated at the outlet temperature solar field for the heat transfer fluid, which was up to 390 °C, in addition to other hypotheses will be identified during the study steps. As a key to solving the issue was initially calculated direct solar radiation for Baghdad city and the result indicates that the frequency distribution of direct solar radiation was not more than 14% of the radiation values which less than 500 W/m2. Thus, the results leads us to the inference that during the months of low temperature in a city such as Baghdad, don't need a large increase in the size of the solar field or keep the solar field as it is and use thermal storage system, be in our case with a small size which is therefore reflected that be a reasonable cost. The power generated from the solar power plant was also calculated for both cases without the use of thermal storage systems and with it, where the capacity of the solar power plant under study with a value of 50 MW, It is noted that the maximum value of the net power was achieved during some months of the year, especially in June, July and August. As for thermal storage, it is clear that the station is work for more than 20 hours during the day in June, July and August. Therefore, the results obtained in this study were compared with the results obtained from the Solar Advisor Model, which was implemented by the National Renewable Energy Laboratory in the United States of America. There was a reasonable consensus in the results, but it does not match exactly because the working conditions of both cases, the geographical position and the situation is completely different weather but remains the general behavior of the two stations is similar.

This paper contains a typical wind blade design for a horizontal Axis Wind turbine. This paper deals with the parameters like blade dimension, Betz limit, calculation of coefficient of lift and coefficient of drag for the defined parameters like tip speed ratio, angle of attack, relative wind velocity, dealing with aerodynamic design principle for a wind turbine blade which includes aerofoil selection and optimal angle of attack. A simulation study has also been carried out to define certain parameters using standard NACA aerofoil for wind blade design.

In adaptive sliding mode observer is designed for momentum biased satellites attitude tracking control with unmeasurable yaw attitude information [1]. A higher-order sliding-mode observer is proposed in nonlinear longitudinal dynamic equations. The observable states can be estimated exactly and the unobservable ones will be identified asymptotically [2]. Firstly, the system is decomposed into two low dimensional subsystems by a restricted system equivalent decomposed method. Secondly, the sliding mode controller is designed based on the restricted equivalent subsystems. The quadratic performance index optimal control technique is introduced to design the optimal sliding mode [3]. The stability of the nonlinear sliding mode is analysed. Simulation results are employed to test the effect of the proposed design algorithm [4]. A decentralized adaptive fuzzy approximation design to achieve attitude tracking control for formation flying in the presence of external disturbances and actuator faults [5].

This paper effort to describe a pioneering method of generating eco-friendly electrical energy that could be obtained from the wind energy harnessed from train. The energy generated from this method can be used to partially fulfil the daily power needs of human being. The method for generating electricity is by using the wind pressure which is generated by fast moving vehicles (train). By channelling the induced wind in the direction of the wind turbine and to convert the kinetic energy of the wind into mechanical energy with the help of wind turbine. The converted mechanical energy is converted into electrical energy with the help of an alternator. The ultimate aim of this project is to develop much cleaner and cost effective way of power generation, which in turns helps to bring down the global warming and to reduce the power shortages. The idea explained here does not interfere in the normal working of the moving train.