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Aims: The increasing development of microalgae applications has led to the concentration of new multidisciplinary studies to facilitate commercial cultivation of these organisms due to cost reduction and productivity enhancement. The aim of this study was the growth and quality optimization of Spirulina biomass by changing the dilution of medium and using the aeration cycle.
Materials and Methods: In this experimental study, the effect of concentration of Zarrouk medium (0 to 100% dilution) and aeration cycle on specific growth rate and dry weight, as well as the content of chlorophyll and carotenoids of Spirulina were investigated, using response surface method, central design. A total duration of 16 hours was aerated in any 24-hour period; the interval time between these aerated periods varied between 1 to 8 hours. The data were analyzed by SPSS 16 software, using multiple regression test.
Findings: The highest biomass (0.659mg/ml) was obtained at 80% concentration of culture media and aeration cycle of 2.75 hours and the highest specific growth rate (0.230 daily) was obtained at 60% concentration and aeration cycle of 4.5 hours. The highest aeration cycle (8 hours) resulted in a significant and simultaneous increase in the content of chlorophyll and carotenoids (11.65 and 2.67 mg/g, respectively).
Conclusion: The growth and quality optimization of Spirulina biomass can be accomplished by changing the dilution of the medium and using the aeration cycle.

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In this research, biodiesel was initially produced from waste vegetable oil by transesterification reaction. The main properties of this fuel were compared with the ASTM D-6751 standard.then, performance of MF-399 tractor engine was tested and evaluated by using 5 to 25 percent biodiesel and diesel blends. Test results showed that, the power and torque of MF-399 tractor engine were increased, using biodiesel and diesel blends. This is because of good combustion of biodiesel due to high oxygen content of this fuel. There was also a slight increase in the fuel consumption and specific fuel consumption of biodiesel and diesel blends due to low calorific value of biodiesel. Results show that the B5D95 blend has the best performance and the lowest increase in specific fuel consumption among the other blends. The fuel consumption and specific fuel consumption of B25D75 was lower than the B20D80 blend. Therefore, if the goal is using high amount of biodiesel, B25D75 blend is recommended for use in MF-399 tractor engine.

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Biofuels are the main substitute to fossil fuels. These fuels are less polluting in compari-son to fossil fuels and can be produced from agricultural material residues for use in die-sel engines. In this research work bioethanol was produced from potato waste. It was de-hydrated in a vapor phase using 3A zeolite and was used in combination with sunflower methyl ester oil and diesel fuel blending which was evaluated thereafter. The sunflower methyl ester was also produced using a transesterification method. Considering the labo-ratory conditions and fuel stability limits to be used, the suitable blending proportion of bioethanol and diesel fuel was determined to be 12 to 88 and then, for maintaining fuel stability at temperatures lower than 15oC, the sunflower methyl ester was added to the mixture. The pour point of the fuel and different fuel blends, the viscosity, cetane number, flash point, amount of fuel ash, sulfur content and copper corrosion were determined in the laboratory. Experiments show that ethanol plays an important role on the flash point of the blends. With the addition of 3% bioethanol to diesel and sunflower methyl ester, the flash point was reduced to 16oC. The viscosity of the blends was reduced with the in-crease in the amount of ethanol. The sulfur content of bioethanol and sunflower methyl ester is very low compared with that of diesel fuel. The sulfur content of diesel is 500 ppm whereas that for ethanol and sunflower methyl ester is 0 and 15 ppm, respectively. The lower amount of sulfur content facilitates the use of fuel blends in diesel engines. For the ethanol and sunflower methyl ester combination, this amount is less than 20 ppm.

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The use of neural networks methodology is not as common in the investigation and pre-diction noise as statistical analysis. The application of artificial neural networks for pre-diction of power tiller noise is set out in the present paper. The sound pressure signals for noise analysis were obtained in a field experiment using a 13-hp power tiller. During measurement and recording of the sound pressure signals of the power tiller, the engine speeds and gear ratios were varied to cover the most normal range of the power tiller op-eration in transportation conditions for the asphalt, dirt rural roads, and grassland. Sig-nals recorded in the time domain were converted to the frequency domain with the help of a specially developed Fast Fourier Transform (FFT) program. The narrow band signals were further processed to obtain overall sound pressure levels in A-weighting. Altogether, 48 patterns were generated for training and evaluation of artificial neural networks. Arti-ficial neural networks were designed based on three neurons in the input layer and one neuron in the output layer. The results showed that multi layer perceptron networks with a training algorithm of back propagation were best for accurate prediction of power tiller overall noise. The minimum RMSE and R2 for the four-layer perceptron network with a sigmoid activation function, Extended Delta-Bar-Delta (Ext. DBD) learning rule with three neurons in the first hidden layer and two neurons in the second hidden layer, were 0.0198 and 0.992, respectively.

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In this study, an electrostatic sprayer which had been previously designed and constructed was evaluated in order to quantify the charging of droplets. Liquid atomization was achieved by using an ultrasonic nozzle. The nozzle maximum flow rate was 25 milliliters per minute and vibration frequency was about 30 kHz. The induction method was used for charging the output droplets. All experiments were carried out within a closed environment with a fixed ambient humidity and temperature to reduce the effect of environmental factors. The independent parameters in this study included: voltage at four levels of 1.5, 3, 5 and 7 kV; air flow speed at six levels of 14, 14.9, 17, 20.2, 21.6 and 23 m s-1; charging electrode radius in two levels of 10 and 15 millimeters, horizontal distance between the electrode and nozzle tip at four levels of 1.5, 6, 10 and 15 millimeters; and liquid flow rate at three levels of 5, 12 and 25 milliliters per minutes. For evaluation of the system, the charging quantities of droplets were measured in different states. The maximum charging occurred at 5 ml min-1 flow rate, voltage of 7 kV, air flow speed of 23 m s-1 and the resulting current was 0.24 μA. On dividing the electrical current by the liquid flow rate and changing the scale, the mean charge to mass ratio was 1.032 μC g-1. Increasing voltage increased the charging quantity slightly but higher voltages and lower air speeds decreased it. The effect of the faster air speed on droplet charging phenomena is positive and the smaller electrode radius causes less charge induction on the droplets. The quantity of droplets charging first increased with increased distance between ring electrode and nozzle tip, and then it was either reduced and/or fixed.

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Aims: In recent years, the increase in the number of construction projects in cities has led to an increase in the demolition of buildings that still have a useful life. Early demolition causes various damages in all dimensions and as a result reduces stability, especially in developing countries. The present study has tried to explain the modernization and adaptation of a system based on sustainable architecture in the Karaj Iron Foundry.
Methods: This research is a qualitative type with an inductive strategy that uses documentary studies and field collection in data collection and uses coding methods to reduce and analyze data. The potential of the Karaj Melting iron factory has been determined based on the ARP method. In the last step, the Shannon coefficient is used to verify the results for each dimension.
Results: According to the results, the highest Shannon coefficient is related to rules, regulations, and the lowest is related to decorations. The contemporization of an industrial space is something that will occur in the context of its design. But this emphasis is caused by placing collective and human spaces in the background of industrial spaces.
Conclusion: The visitor should draw a clear and appropriate picture of the site in the past. Finally, this study has provided solutions to improve the current situation of construction and prevent the demolition of buildings that have a useful life in the Karaj Iron Foundry, which has considered maintenance, adaptation, and modernization as an important cause of these demolitions.

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Aims: Sustainability assessment systems are an important tool for measuring and managing actions taken in architectural works. The main goal of the research is to measure the efficiency of the DGNB system in management and programming the architectural interventions in the Karaj Iron Foundry.

Methods: descriptive-analytical research method is adopted in the article. The method of data collection is archieve documentary. the Karaj Iron Foundry as a shared heritage of Iran and Germany is selected as case study of the reserch. The monument was built by famous German, Austrian, Italian, Swiss, etc. architects between World War I and World War II, and it is worth considering as a world heritage site.

Findings: The findings of the research in the Karaj Iron Foundry based on the DGNB system indicate that the environmental quality with 20% influence on the sustainability is in the first place, the economic quality is in the second place with 17.9%, and the social quality is in the second place. Cultural and functional quality with 16.7% stand in third place, technological quality with 15.3% stands in fourth place, process quality with 15.2% stands in fifth place and finally site quality with 15% stands in sixth place.

Conclusion: The results indicate the efficiency of the DGNB rating system in programming an action framework for the Karaj Iron Foundry. Therefore, it is possible to recommend the adoption of this sustainability evaluation system in managing the action process in other valuable works of contemporary heritage and industrial architectural heritage.

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Tomato is a major fruit, as well as a major food science product. There is a need of determining the quality attributes of this fruit (nondestructively) due to the increasing demand of the in agro-industrially controlled areas. Most of the commonly employed techniques are time consuming and involve a considerable degree of manual work. Sample preparation, juice making, and laboratory tests are among the limitations. Raman spectroscopy was applied in this study to measure such important quality parameters of tomato as SSC, pH and color. A dispersive Raman instrument was employed and reference analyses were carried out to make calibration models regarding the spectral features and target attributes. Analysis of the spectra revealed that all the three characteristic bands of cartenoids, lycopene, and carotene, were significantly recognizable. Also there were several strong to medium bands recognized as related to carbohydrates. Principal Component Regression (PCR) and Partial Least Square (PLS) were selected as the multivariate calibration models. The prediction models proved to be robust resulting in a desirable mapping between the spectra and output attributes. The Root Mean Square Error of Predictions (RMSEP) through PLS and PCR for modeling the color index using the whole spectrum was obtained as 0.33 and 0.38, respectively. RMSEP for mapping the SSC using PLS and PCR models was resulted in respective figures of 0.30 and 0.38. PCA interpretation depicted that Raman spectra could make a favorable distinction among the samples based on their maturity stages. As a result, there is a great potential to use Raman spectroscopy in industrial approach and in line control.

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Jujube (Zizyphus jujube Mill), a valuable medicinal plant, is consumed either as fresh fruit or dried product in Iran. Drying jujube guarantees a longer shelf time while preserving its quality to be used in medical and pharmaceutical industries. In this research paper, the influence of several drying conditions on the effective moisture diffusivity, activation energy, energy consumption and required specific energy in the drying of jujube is presented. Temperature levels of 50, 60 and 70 ºC and hot air velocities of 0.5, 1 and 1.5 (m s-1) were used as the treatments. Effective moisture diffusivity of jujube fruit during the drying process was in the range of 1.1532-5.1895×10-10 (m2 s-1) for the first period and 0.4036–2.3064×10-10 (m2 s-1) for the second period. Also, the values of energy of activation in both periods were determined to be between 34.97 and 74.20 (kJ mol-1). The energy consumption and the required specific energy for drying were in the range of 79.1- 92.46 (kW h) and 203.59 – 900.08 (kW h kg-1), respectively. Results show that energy consumption diminished when temperature increased at each air velocity, while it increased with increasing hot air velocity.

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In this paper, the performance evaluation of a two-way hybrid photovoltaic/thermal (PV/T) solar collector was analytically and experimentally carried out. Mathematical expressions for operating parameters in glass to glass and glass to tedlar PV/T solar collectors were developed and experimentally validated by a glass to tedlar PV/T solar collector system. Also the influence of air flow rate on the solar collector performance was investigated. The results showed that the glass to glass PV/T solar collector gave higher outlet air temperature, cell temperature and thermal efficiency than the glass to tedlar PV/T solar collector. However, back surface temperature and electrical efficiency were higher in case of glass to tedlar collector. Increasing the air flow rate led to a lower outlet air temperature and a higher electrical efficiency of the photovoltaic module. Maximum experimental electrical efficiency, thermal efficiency and overall thermal efficiency for the glass to tedlar PV module were found to be 10.35, 57.9 and 84.5%, respectively.

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 This study was carried out to determine the effect of seed growing regions and loading speed on some mechanical properties of castor seed. These properties are used to design and improve related machines such as expeller that are used for extraction of oil from castor seed. Mechanical properties of castor seed were expressed in terms of rupture force and energy, bio-yield force, apparent modulus of elasticity and toughness using material testing machine. Factorial test with Completely Randomized Design (CRD) was used to study the effect of velocity (4 levels: 5, 15, 25, 35 mm min^-1) and seed growing regions (Izeh, Dezfoul, Baghmalek, Shoushtar and Urmia). The results showed that the effect of seed growing region on force, modulus of elasticity, bio-yield force and rupture energy was significant. Izeh seed had the maximum rupture force (75.11 N) whereas Dezfoul and Shoushtar seed had the minimum amount of rupture force (approximately 42 N). Also, loading speed had a significant effect on modulus of elasticity and rupture energy. With the increase of loading speed modulus of elasticity of Baghmalek seed decreased significantly from 144 to 65.5 MPa. Finally, interaction effect of seed growing region and loading speed was significant for most properties. In this research work, an extrusion system was designed and fabricated for the extraction of castor oil.

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Biodiesel fuel, which is produced by transesterification reaction between alcohol and vegetable oil/animal fat is proposed as a clean alternative to petro diesel fuel. Today, one of the new technologies to produce biodiesel is using ultrasonic energy that makes production faster, with improved quality and less expensive. Various factors that affect the design of ultrasonic reactors are ratio of vibrating rod diameter to reactor diameter, reactor height, depth of horn penetration into fluid and chamber characteristics (material and shape). In this paper, two parameters namely the ratio of vibrating rod diameter to reactor diameter and reactor height were studied in order to increase the reaction efficiency. In all performed tests, the horn diameter of 14 mm, molar ratio of alcohol to oil of 5 to 1, catalyst concentration of 0.7% wt?? oil, depth of horn penetration into fluid of 15 mm and a cylindrical reactor were used. Experimental design involved the use of Central Composite Design (CCD) and the statistical Response Surface Methodology (RSM). Considering the empirical model, a significant relationship was found between independent and dependent variables with a regression coefficient of 0.99. Taking into account the desirability of increasing the efficiency, the optimal function of reactor diameter and reactor height were 63 and 110 mm, respectively with a reaction yield of 87%. In order to verify the model, function responses in the defined area were tested with five replicates and the average efficiency of the reaction was 87.2%. The obtained model suggests the simultaneous reverse effects of reactor diameter and height on the reaction efficiency.

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One of the important bottle-necks in production of microalgae based biodiesel is the lack of an efficient method for harvesting of microalgae from the culture medium. In this study, the electroflocculation method was developed for harvesting of microalgae Dunaliella cells from culture medium. The effect of several parameters such as the current density, electrical conductivity of culture medium, time, electrode gap, and electrode type on harvesting efficiency and energy consumption were also determined. The maximum harvesting efficiency of this method was 97.44% at EC= 1.35 S m-1 and current density of 90 A m-2 during 3 minutes electroflocculation process in a 300 ml beaker. The maximum efficiency was achieved by aluminum electrodes with 1 cm distance between electrodes and the maximum energy consumption for this practice was 0.621 kW h m-3. It was concluded that electroflocculation is an efficient and cost effective method for microalgae harvesting.

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Biodiesel is a renewable and sustainable alternative fuel that is derived from vegetable oils and animal fats. In this paper an experimental investigation is conducted to evaluate the use of soybean oil methyl ester (biodiesel) in the diesel fuel at blend ratios of B0, B2, B5 and B10. In this study, the performance and emissions characteristics of conventional diesel fuel and biodiesel fuel blends were compared. The tests were performed at steady-state conditions in a direct injection diesel engine with 90 kW power that was equipped with EGR and with no modification of calibration. The experimental results of brake-specific fuel consumption (BSFC), torque and exhaust temperature as well as carbon dioxide (CO2), smoke, nitrogen oxide (NOx), carbon monoxide (CO) and unburned hydrocarbon (UHC) emissions were presented and discussed. The results of engine performance parameters at different conditions (different load and engine speed) showed that a negligible loss of engine power and a significant increase in brake specific fuel consumption due to lower heating value of biodiesel. Smoke, CO and HC emissions were decreased by increasing blends of soybean oil as compared to pure diesel. However the increase in engine NOx and CO2 emissions were observed with the increase of biodiesel percentage in the blended fuel.

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In the present study, saffron was dried using a heat pump-assisted hybrid photovoltaic-thermal solar dryer. The effect of different drying air temperatures at three levels (40, 50, and 60^oC) and two different modes of the dryer (with and without heat pump system) were investigated on drying behaviour of saffron. After collecting the pertinent data, eleven drying models were used to describe drying characteristics of saffron. Quality characteristics of the dried products (including: colouring, aromatic strength and bitterness) were also evaluated. The results indicated that drying time decreased by 62% with increasing air temperature from 40 to 60^oC. Moreover, applying heat pump with the dryer reduced RH of drying air and, consequently, enhanced drying rate and shortened drying period by 40%. A two-term drying model presented a relatively higher R² and lower, MBE, and RMSE values at both modes of drying and, therefore, was selected to explain drying behaviour of saffron among the other models. The results of saffron quality evaluation showed that colouring characteristics of saffron improved with drying temperature and heat pump system. Meanwhile, aromatic strength of saffron increased with increasing air temperature. But, no significant change in bitterness was observed at different levels of temperature and heat pump system.

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In this research, an intelligent method is introduced for remaining useful life prediction of an internal combustion engine timing belt based on its vibrational signals. For this goal, an accelerated durability test for timing belt was designed and performed based on high temperature and high pre tension. Then, the durability test was began and vibration signals of timing belt were captures using a vibrational displacement meter laser device. Three feature functions, namely, Energy, Standard deviation and kurtosis were extracted from vibration signals of timing belt in healthy and faulty conditions and timing belt failure threshold was determined. The Artificial Neural Network (ANN) was used for prediction and monitoring vibrational behavior of timing belt. Finally, the ANN method based on Energy, Standard deviation and kurtosis features of vibration signals was predicted timing belt remaining useful life with accuracy of 98%, 98% and 97%, respectively. The correlation factor (R2) of vibration time series prediction by ANN and based on Energy, Standard deviation and kurtosis features of vibration signals were determined as 0.87, 0.91 and 87, respectively. Also, Root Mean Square Error (RMSE) of ANN based on Energy, Standard deviation and kurtosis features of vibration signals were calculated as 3.6%, 5.4% and 5.6%, respectively.

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Solar radiation data play an important role in solar energy relevant researches. These data are not available for some locations due to the absence of the meteorological stations. Therefore, solar radiation data have to be predicted by using solar radiation estimation models. This study presents an integrated Artificial Neural Network (ANN) approach for estimating solar radiation potential over Iran based on geographical and meteorological data. For this aim, the measured data of 31 stations spread over Iran were used to train Multi-Layer Perceptron (MLP) neural networks with different input variables, and solar radiation was the output. The accuracy of the models was evaluated using the statistical indicators of Mean Absolute Percentage Error (MAPE), Root Mean Square Error (RMSE), and Correlation Coefficient (R); hence, the best model in each category was identified. The Stepwise Multi NonLinear Regression (MNLR) method was used to determine the most suitable input variables. The results obtained from the ANN models were compared with the measured data. The MAPE and RMSE were found to be 2.98% and 0.0224, respectively. The obtained R value was about 99.85% for the testing data set. The results testify to the generalization capability of the ANN model and its excellent ability to predict solar radiation in Iran.

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