فهرست مطالب mohammadhossein kianmehr

Due to the shortage of water resources and frequent droughts, optimizing the use of food resources to provide feed for animal is an important issue. In this study, pistachio shells were collected and stored in open air environment to reduce their moisture content. Then, they were powdered using a grinder to produce pellets using a developed hydraulic pelletizer, and the mechanical properties of the produced pellets were measured using a biological material testing machine. An experimental design with four factors, including moisture levels of 15 and 20%, particle sizes of 0.6 and 1 mm, mold diameters of 8 and 10 mm, and compression pressures of 6,000, 8,000 and 11,000 kPa, was carried out in a completely randomized design. The density, fracture energy, and toughness of the produced pellets were measured. The results showed that the independent effects of moisture, mold diameter, and compression pressure were significant on all the above properties (P ≤ 0.05), and the effect of particle size was significant on the density and toughness of the pellets (P ≤ 0.05). Additionally, some of their interactions had a significant effect on the density, fracture energy, and toughness of the pellets (P ≤ 0.05). The coefficient of variation and determination coefficient were 1.92% and R2= 0.83 for density, 25.42% and R2= 0.49 for fracture energy, and 66.23%, R2= 0.41 for pellet toughness, respectively. Therefore, producing pellets from pistachio shell waste can be a good option to reduce transportation costs, produce Animal feed, and reduce environmental pollution.

 This study investigated the pelletization ability of green pistachio shell residues, its effect on anti-nutrients, and several physical and mechanical properties of pistachio shell pellets produced with an industrial and custom-made pelletizing machine. In this experiment, the designed device was utilized with pistachio green shell residues containing 15% moisture, 1 mm particle size, and a temperature of 65 °C. To improve adhesion and reduce antinutritional substances of pistachio residues, bentonite, wheat, urea, and molasses were used at 3, 6, 4, and 5 kg, respectively, per 100 kg of pistachio residues. The density, maximum breaking force, breaking energy, phenolic compounds, tannin, acid detergent insoluble fiber (ADF), (NDF) of the pellets produced were determined. Furthermore, the maximum breaking force and breaking energy of the pellets produced by the machine for testing biological materials were measured. The Student's t-test was used to analyze statistically the parameters measured in the pellets produced by two Peltzen machines. The research results showed that the density of pellets produced in the industrial machine was significantly higher than in the custom-made machine (p<0.05). Conversely, the breaking energy of the produced pellets in the custom-made machine was higher than in the industrial device (p<0.05). The amount of phenolic compounds, tannin, ADF, and NDF for the designed Peltzen device was 19, 26, 12, and 10% less than the industrial Peltzen device, respectively (p<0.05). In general, it can be concluded that the designed device improves the quality and reduces antinutritional substances in the pellets of green pistachio shells.

This study is the first attempt to solid-phase humification of Lignite for activation of nitro-humified substances (NHSs) towards improve the cleaner application of lignites in agriculture and the environment. Ozone oxidation and additives of urea and KOH were used as accelerator of humification process, nitrogen enrichment and humic acid activating agent, respectively. In order to elucidate the solid-phase humification performance of lignite, indicators such as total humic acids (THA) and the water-soluble humic acids (WHA), nitrogen/oxygen content, C/N ratio, degree of oxidation (O/C) obtained from CHNOS elemental analysis, and carboxylic and phenolic functional groups content were evaluated. Toward the confirmation of changes of the oxygen-nitrogen containing functional groups as well as effective nitrogen transformation in the humification process, FT-IR spectroscopy and analysis of distribution percentage of incorporated bonded nitrogen forms were studied. Experiments and data collection of this research were completely conducted in 2021-year in the college of Abouraihan-University of Tehran and in the laboratories located in department of biosystems engineering. In continuation, response surface methodology based on the central composite design (CCD-RSM) was used to determine the optimal conditions, and mathematical models were developed to accurately predict the changes of THAs and the WHAs. Under the optimal conditions of 8 g/h of ozonation rate, 15 min of oxidation time, 14.85 %wt. of KOH and 30 %wt. of urea, the yield of THA and WHA were 69.02% and 53.32%, respectively which were significantly higher than the control samples (30% and 7%, respectively). The uniform distribution of binded nitrogen forms in the NHSs showed that 47% of the total nitrogen content in the NHSs was in the form of ammonium nitrogen, 16% in the form of amide nitrogen and 37% in the form of highly bonded organic nitrogen with very strong bonds. By assist of ozone humification, the content of phenolic and carboxylic acid groups increased by 85.71% and 215.87%, respectively. The optimized process resulted in superior quality indicators, including less carbon, more nitrogen and consequently lower C/N ratio, higher O/C ratio, lower aromatic carbon, and more aliphatic and carboxylic carbon for developed NHSs.

 In this work, solid-phase nitro-humification process was developed to activation of lignitic nitro-humic substances (NHSs) by using the two-step sequential treatment assisted by nitrogen enrichment (using KOH and urea as a humic acid activator and a nitrogen enrichment agent, respectively) and ozone oxidation in fixed-bed reactor. The changes in main elements, spectral index of humification (E4/E6), surface functionalization, and textural properties were determined by CHNOS analysis, ultraviolet-visible (UV-VIS), Fourier-transform infrared (FT-IR) spectroscopy, and specific surface area (SSA) analysis based on BET, BJH and t-plot models, respectively. The results revealed the increasing 2.25 and 2.94-folds on the yield of alkali and water-soluble NHSs, respectively, compared to the conventional alkaline extraction method. A 14.5% reduction in the carbon content owing to ozone oxidation and 8.15% nitrogen enrichment resulting from urea pretreatment led to an ideal humification ratio (C/N ratio=5.6) and a higher degree of oxidation (O/C ratio=0.94). Also, E4/E6 ratio up to 6.8 and salt index of 46.2% for NHSs were at an acceptable level. The decomposition of double bonds of aromatic carbons and the effective transformation of nitrogen into amide and organic nitrogen forms due to ozone oxidation were well proven by elemental analysis of CHNOS and FT-IR spectroscopy. As a result of ozone oxidation, the main pores in lignite were mainly turned into mesopores. Collectively, the results demonstrated that ozone oxidation, in addition to enhancing the yield and quality of NHSs, provide an end product with a competitive value and a lower price than other commercial nitrogenous humic fertilizers.

Due to the increasing population growth today, the need for new technologies for better food processing is felt more and more. New thermal and non-thermal technologies based on physical techniques for food preservation have the ability to meet consumer demands and deliver processed foods with high quality and long shelf life, without additives. Among these heating and food processing methods are Pushed Electric Fields (PDE), High Voltage Electric Fields (HVED), Moderate Electric Fields (MEF), Ohmic Heating (OH), Pulsed Ohmic Heating (POH). Meanwhile, one of the great alternative methods for heating is ohmic heating. The ohmic heating process is an alternative method that uses electrodes to convert electrical energy into heat. Electrical conductivity of heating materials is one of the factors that determine the effectiveness of ohmic heating system. Ohmic heat can be produced effectively and efficiently from materials with electrical conductivity between 0.01 and 10 S/m. Currently, there is a wide use of ohmic heating potential in the food industry. Ohmic heating is most widely used in the food industry, including the inactivation of pathogens, enzymes, and the removal of some inappropriate compounds in food.

Densification of biomass materials such as briquette improves the management properties of materials for transportation, storage, and so on. This study aimed to determine the optimal conditions of the briquette production process using a hydraulic press from the combination of bagasse and walnut shell using response surface methodology. The effects of independent variables including bagasse particle size (PS), process temperature (PT), bagasse moisture content (MC), and the composition ratio percentage of the walnut shell to bagasse (CR) were evaluated at three levels on the response variables of the density and tensile strength. The calorific value of the briquette was determined through validated linear and nonlinear equations of the high heat value using the proximate analysis of volatiles, fixed carbon, and ash. The results showed that by decreasing the moisture content of bagasse particles, the density and tensile strength of the briquette increased. Adding walnut shell particles to the briquette produced with the size of fine particles reduces tensile strength. The briquette production significantly reduced the percentage of volatile materials relative to their biomass and increased the percentage of fixed carbon. The calorific value of the raw material sample relative to the briquette produced increased from 16 to 22 MJ/kg. The optimal values of the density and tensile strength of briquettes were equal to 867.847 kg/m3 and 1.356 MPa, respectively at the CR of 5%, PS less than 1.18 mm, MC content of 7%, and PT of 360 °C. At this condition, the calorific value of 22 MJ/kg was obtained.

The stability and maturity indicators of composted biomasses are important to ensuring the quality of the final product, maintaining the consumer confidence, and guaranteeing the safe applicability in agricultural uses. In addition, due to the low energy density and bulk density, the composted biomasses face problems such as higher storage and transportation costs as well as overall costs in logistics management. Particle size reduction and densification of composted biomasses can partially overcome these challenges.

Sugarcane bagasse compost (SBC) was prepared from South bagasse processing development company (Biofer) to quality characterization and assessing the grinding process toward densification. For assessing the quality of SBCs, the physicochemical characterization as well as the analytical techniques were investigated through differential scanning calorimetry (DSC), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) and scanning electron microscopy (SEM). In the following, a hammer-attrition mill was used to improving the physicomechanical properties and reducing the particle size of SBCs. To this end, an experimental design in the form of factorial design (D-optimal) was used to assessing the significance and optimization of the effects of moisture content of SCBs (8, 12, and 16 w.b.%) and screen opening size (1, 2.5, and 4 mm) and rotational speed (1400 and 2000 rpm) of hammer-attrition mill as independent variables on specific energy consumption and bulk density as design responses.

The results obtained from chemical analysis exhibited that the properties of SBCs are accordance with existing standards. The SEM micrographs revealed a physical change on the surfaces of SBCs with a wrinkly and heterogeneous morphology along with longitudinal cracks with opening of fiber bundles in cellulose resulting from the degradation of lignin and hemicellulose. This trend was also demonstrated by XRD analysis, so that with increasing the crystallinity index (from 62 up to 75), the crystalline regions of cellulose in SBCs remained unchanged, but the amorphous regions, which includes hemicellulose and lignin, was slightly decomposed. Changes in functional groups from FT-IR spectra demonstrated that the microbial-biological degradation of lipids and carbohydrates, as well as dissociation of lignin and polyphenols was occurred in SBCs. From the DSC thermal curves, a glass transition temperature of 89.7 °C was obtained for SBCs, which due to the peak intensity at this point, the improved maturation and humification of SBCs is guaranteed. For both responses of specific energy consumption and bulk density of SBCs, a two-factor interaction (2FI) model with the highest correlation coefficient and the lowest standard deviation was proposed. The mesh opening size had the greatest effect among the parameters on the specific energy consumption and the bulk density.

The results demonstrated that the use of comprehensive analytical analyses for accurate and comparative study between the final composted biomasses and the raw materials in terms of stability and maturity indicators, is practical and reliable. Optimization results from D-optimal design showed that under optimum conditions of moisture content of 8 %w.b, 1-mm mesh opening size and rotational speed 1400 rpm of hammer-attrition mill, a minimum amount of SEC (141.38 KJ/Kg) and the maximum amount of bulk density (209.62 kg/m3) were introduced as optimum responses with the desirability function of 0.88.

In circular bioeconomy viewpoint, sustainable development of biorefineries requires to use the lignocellulosic biomass completely to produce high value-added bioproducts. The lignin products market was 750 million US$ in 2018 and is predicted to reach 1460 million US$ by the end of 2025. In industrial processes, the large amounts of industrial lignins as technical lignins or biorefinery lignins are formed as by‐products. Annually, about 150-180 million tons of industrial lignins is generated in worldwide. Most of industrial lignins are directly combusted to obtain heat, which not only is a loss of organic matter but also leads to environmental pollution issues. Therefore, developing the lignin-based fertilizers has become an important research topic for eco-friendly agricultural practices. Interestingly, lignin can be used as slow‐release carriers, coating materials, soil conditioners and chelated micro-fertilizers due to its excellent slow-release properties, chelating and other functionalities. Lignin-based fertilizers have several specific properties including the slow dissolution, adsorptivity, biocompatibility, controlled-release, biodegradability, nonvolatility, long-term stability, anti-leaching, low pollution, high fertilizer efficiency, low price and higher biological activity. Lignin can delay the dissolution of the nutrients (nitrogen, phosphate, etc.) in the modified fertilizer to improve the slow-release performance and also delay hydrolysis of urea by inhibiting the soil urease activity and inhibit the conversion of NH4+-N to NO3--N, thereby increasing the utilization of NH4+-N. Lignin‐based fertilizers prepared by sustainable chemical, coating and micro-chelation modifications. This review, exhaustively scrutinizes and reports the recent research advances in the lignin extraction methods, underlying mechanisms, characterization and applications of the above methods for preparing lignin‐based fertilizers.

Today, the use of biodegradable coatings has become an effective solution for pelletized agro-biowaste fertilizers due to the synchronizing of the nutrient release according to the plant requirements and reducing the environmental issues. In this study, three agro-biowaste compost including poultry manure (40%), cattle manure (30%), and agricultural biomass (30%) were mixed at the 40% moisture content, and then the pelletization process was carried out using the screw extruder. A factorial experiment in a completely randomized design with three replications was developed for assessing the effect of four biodegradable coating materials (humic acid, canola oil, corn starch, and nano-silica) and three coating methods (dip coating, spray coating, vacuum coating) on sustainability attributes of coated compost pellets such as pellet disintegration time, water absorption, humidity absorption, and water contact angle. The results showed that the canola oil – vacuum method applied for coated compost pellets with disintegration time (1735 min), water absorption (57.6%), humidity absorption (4.3%), and water contact angle (69°) was the best treatment. This coating method showed a 36-fold increase in disintegration time and a 3.7, 7, and 1.6-fold decrease in water absorption, humidity absorption, and water contact angle, respectively as compared with uncoated compost pellets. The nitrogen release rate of the coated compost pellets showed that the amount of total nitrogen at disintegration time was 25%. Also, 75% of nitrogen was released into the soil during 55 days, which confirmed experimental results and improved the nitrogen release rate by 45 days as compared with uncoated compost pellets. Overall, from the results of this study, it can be concluded that pelletized compost fertilizer which was coated by canola oil-vacuum method, shown a high resistance to water, enhanced sustainability and reduced nitrogen-release rate property as it could supply nutrient to the plant for a longer period.

To increase the applicability of compost for agricultural utilizations on a large scale as a sustainable slow-release nitrogen fertilizer, as well as reducing the limitations of their handling, transportation, and storage, it is important to improve their physical and mechanical properties, and pelletization is the most applicable process to achieve these goals. In the present study, the pelletizing process of sugarcane bagasse compost using a closed-end die within a single pelletizer unit was investigated. Composted hammer milled sugarcane bagasse with three particle size (1, 2.5, and 4 mm), three moisture content (8, 12, and 20 %) under three compaction pressure (50, 100, and 150 MPa) was densified and the effect of these factors on specific energy consumption, maximum breaking strength and density of produced pellets were evaluated and optimized by response surface methodology (RSM). The optimum value of specific energy consumption (2.11 MJ/t), maximum breaking strength (28.35 kg), and particle density (0.871 g/cm3) were suggested from BBD-RSM for pelletization of sugarcane bagasse compost under optimal conditions of using 4-mm particle size, 20 wb% moisture content and 50 MPa compaction pressure with desirability function of 0.706. Then, the rate of nitrogen release in soil and water for pelletized mixed sugarcane bagasse compost-urea fertilizer at a ratio of 1:1 wt% was investigated. The results of the nitrogen release rate showed that 61% of nitrogen was released into the water during five days while the release of nitrogen in soil was 80% during 98 days for pelletized mixed compost-urea fertilizer. In general, the findings of this study showed that the pelletized fertilizers produced from the compost-urea mixture are capable to supply nitrogen to the plant for a longer period relative to conventional nitrogen fertilizers such as urea. It could be deduced from this research that pelletized mixed compost-urea fertilizers have great potential for use in crop nutrition as a sustainable slow-release nitrogen fertilizer.

Wheat straw is widely used for animal feed and biorefinery to sugar production. However, cellulose, which is the major source of sugar, is protected by lignin. Ozone is a powerful oxidizer that can deconstruct lignin and makes cellulose accessible to enzymatic digestion. The aim of this study is the delignification of wheat straw using ozonolysis technology as a green, environmentally friendly, and energy-efficient process. Modeling and optimization were performed by response surface methodology and the effects of five factors including ozone production rate (1, 2, and 3 g/h), reaction time (15, 30, and 45 min), the flow rate of ozone/oxygen (0, 3, and 6 L/min), moisture content (100, 200, and 300% w/w) and urea (0, 1.5, and 3% w/w) were investigated. The results of this study showed that the highest delignification (50%) was observed in the highest levels of ozone amount, time, flow rate, urea, and the lowest level of moisture content. The flow rate and moisture content factors were the most contributing factors in the delignification process with 36 and 20%, respectively. Under optimal conditions, 49.8% of delignification was obtained at an ozone amount (3 g/h), time (45 min), flow rate (5.7 L/min), moisture content (100% w/w), and urea amount (3% w/w) with a desirability index of 0.99. The response surface method creates a desirable fitness between the experimental and predicted responses with R2=0.90. The results showed that the ozonolysis process using the proposed factors can be used to delignification of wheat straw.

Production of high purity humic acid with desirable quality properties for different uses is dependent on extraction and purification methods in its production process. The research literature showed that, in order to achieve this, separation of fulvate compounds and inorganic elements from alkaline humate extracted from raw materials is paramount significant. The main purpose of this study was the separation of alkaline humates from fulvates and inorganic elements by membrane separation technology. Spent mushroom compost (SMC) was used as organic waste for extraction of humic compounds including humates and fulvates with alkaline treatment method. Then, a membrane separation process with a mini-pilot system equipped with frame and plate module and polysulfone membrane with molecular weight cut-off 5 kDa was tested. The effect of transmembrane pressure (TMP) with four levels of 50, 150, 250 and 350 kPa on separation performance including permeate flux of fulvates, predominant fouling mechanism, fouling index (i) and fouling resistances as well as chemical and spectral properties and purity percentage of the resulting humic acid ultrafiltered from humate retentates were investigated. The results of this study showed that by increasing of pressure, permeate flux of fulvate compounds increased by 41.8%. Based on the Hermia model, the predominant fouling mechanism in all pressure levels were cake layer formation. The results of the fouling index (i) showed that all of the fouling mechanisms occurred in the membrane system, and by increasing pressure, complete pores blocking and cake layer formation were occurred faster and earlier respectively. Scanning electron microscopy (SEM) analysis in order to confirm of experimental data of fouling phenomenon showed that by increasing pressure from 50 to 350 kPa, layer thickness accumulated on the membrane surface was increased 3-fold. Evaluation of ultrafiltered humic acid characteristics showed that membrane separation technology played an effective role on chemical and spectral properties of humic acid compared to other purification methods, and increased final purity of humic acid to 87.8%.

The hypothesis of the sufficiency of plant water content in extraction process was studied in theory. Essential oil extraction device was manufactured using a non-distillable gas instead of water vapor and evaluated quantitatively and qualitatively. The results of experiments on the manufactured device resulted in the optimum extraction mode using the air cycle and showed that the highest efficiency was obtained at lower speeds and higher air temperatures. Also the results showed that the extracted essential oil by new method in all states is less than the essential oil obtained with steam distillation. The results of analysis of samples using GC/MS showed that the percentages of the compounds in the samples obtained from the gas cycle and water distillation methods were different. For example, the percentage of limonene in the essential oil of Clevenger was 12.24 and in the gas cycle method was 0.22.

Capacitive deionization (CDI) is an emerging energy efficient, low-pressure and low-cost intensive desalination process that has recently attracted experts’ attention. The process is to explain that ions (cations and anions) can be separated by a pure electrostatic force imposed by a small bias potential. Even at a rather low voltage of 1.2 V, desalinated water can be produced. The process can be well operational by a professional cell design. Although various processes have been manufactured before, in this study, membrane was removed and a new unit was designed and manufactured (Using CFD Simulation). In this case, the combination of activated carbon powder (with an effective surface area of 2600 m2 per gram), carbon black, and polyvinyl alcohol with a ratio of 35/35/30 coated on carbon paper as electrode materials was considered for tests. The weight was 1.41 grams for each material, and the thickness was 0.44 mm. CDI system was tested, and the results of charge-discharge cycles, cyclic voltammetry, and impedance spectroscopy were evaluated. It can be implied that there is no need for a strong pump and, also, pressure drop can be reduced due to such a noticeable space between two electrodes. Preliminary experimental results showed high specific capacitance (2.1 Farad) and ultra-high salt adsorption capacity, compared with similar cases.

Compression is one of the suitable solutions to reduce the volume of biomass materials. The cattle manure pellet production (extruder) transforms manure into pellet in the humidity range of 35 to 45 percent (based on the wet). The use of a size reduction machine is necessary for grinding cattle manure in pellet production.  The objective of this study was determining specific energy consumption for grindingwet cattle manure at three levels of moisture content of cow manure (35, 40 and 45 % w.b) and three levels of thrasher unit rotational speed (150, 200 and 250 rpm) using special size reduction machine. The experiment was a factorial arranged in a Randomized Complete Design with three replications. One Kg of cattle manure was grinded in each test and the particle size of grinded cattle manure was determined. The highest specific energy consumption was 4.62 (KJ / Kg) for thrasher unit rotational speed of 150 rpm at 45 % (w.b) moisture content. The thrasher unit rotational speed was negatively connected with specific energy consumption, such that in the highest rotational speed of thrasher unit (250 rpm), lowest specific energy consumption (1.72 KJ/Kg) was observed. The lowest geometric mean diameter of wet cattle manure was 1.02 for thrasher unit rotational speed of 200 rpm at 35% (w.b) moisture content.

Microfiltration can clarify pomegranate juice; however, fouling is a limiting phenomenon in the process. In current work ultrasound was applied above and below the membrane surface to reduce fouling after removing temperature effect. A hydrophilic mixed cellulose ester membrane with pore size of 0.45 μm was used in lab scale flat sheet module. Membrane module was placed above and below the ultrasonic probe with frequency of 30 kHz and power of 1000 W, separately. The feed temperature in ultrasonic-membrane process was recorded and the experiment was repeated without ultrasonic treatment in similar feed temperature. Results showed that ultrasonic treatment above the membrane surface can increase the permeate flux; however, difference between the permeate fluxes was only before the steady state condition. On the other hand, the ultrasonic treatment below the membrane surface compared with the process which was performed without ultrasonic treatment cannot change the permeate. Also standard blocking was the main fouling mechanism in the membrane process which was equipped with the ultrasound probe above and below the membrane surface. Evaluation of blocking index showed that the cake formation is the main fouling mechanism all over the time in the process where ultrasound probe was inserted above the membrane surface. However, inserting the ultrasound probe below the membrane surface changed the value of blocking index. In this configuration cake formation was followed by intermediate blocking, standard blocking and complete blocking.

Separation of inorganic materials and fulvate compounds from alkaline humate solutions is very important due to obtaining a better quality and more purified humic acid. For this reason, in this research a membrane separation system was used to separate fulvate compounds from humate solutions obtained from alkaline extraction of lignite coals (low rank coal). A hydrophilic ultrafilter membrane of polysulfone material with a pore size 5 kDa was employed using a plate and frame module. The effect of temperature (35, 45 and 55°C) on the membrane performance such as permeate flux of fulvates, fouling percentage, total membrane resistance and membrane resistance (RT and Rf), and morphology of membrane layers were investigated. Also, the influence of temperature on the humic acid purity obtained as retentate was determined using gravimetric analysis. The results of this work showed that by increasing the temperature from 35 to 55 °C, the value of permeate flux of fulvates was increased by 38%. Multiple behaviors were observed in the membrane fouling and resistances by increasing the temperature. The cake layer formation mechanism was obtained as dominant of fouling in 35°C temperature according to Hermia’s theoretical model results

Pomegranate juice (PJ) contains large particles that stick to evaporator walls causing off flavors in the concentrate due to burning. Microfiltration is used to clarify PJ. Fouling is a limiting phenomenon that can prevent the industrialization of membrane clarification. Changes in the geometry of the membrane module such as using baffles are useful to decrease this problem. Computational fluid dynamics (CFD) is a powerful numerical tool used in modeling membrane processing.
The effect of baffle geometry on the efficiency of membrane clarification of pomegranate juice in a flat-sheet module was simulated using computational fluid dynamics (CFD). The geometry of the membrane unit was plotted and meshed with Gambit software, and was solved using FLUENT software. A two-dimensional double-precision method at steady state was selected to simulate the membrane process. The convective terms were discretized with a standard first-order upwind scheme in computational solution. The RNG k- model was used due to its high accuracy in eddy flows with a low Reynolds number. The effects on the process performance of the number of baffles, their angle and the distance between the baffles and the membrane surface were evaluated.
The results showed that the configuration with the feed-channel height of 2 cm, the baffle angle of 90o and the distance between the membrane surface and baffles of 2 mm had maximum permeate flux.
Reducing the distance between the baffles and the membrane surface increased the permeate flux due to create an eddy flow near the membrane surface in the flat-sheet module and reduced the total and cake-layer resistances.

The optimal use of rotary seed coater needs the knowledge of the physical properties and the behavior of seed motion in rotary drum. One of the most important parameters in such equipments is the rotational speed of the drum which causes the rolling action of seeds. In this research a new method was used for measuring these properties which was based on the motion of seeds in a less than 50% filled rotating drum. Firstly the angle of repose of three types of seed (vetch, wheat and tomato seed) with different shape was measured with different methods and the values ​​obtained were compared. Then, the lower and upper angle of repose were also measured by rotary drum. At the final step, the rotational speed of the drum were gradually increased from 0 to 100 rpm. The speed of the drum which caused the seeds rolling motion to start and end was also measured. The results showed that the shape of the seeds had a great impact on the type of motion in the rotating drum and it was obtained that the vetch seeds had the widest speed range with rolling mode of motion (from 1 to 65 rpm). However, this range for tomato seeds is from 8 to 40 rpm and for wheat seeds from 6 to 49 rpm. Finally the increase of filling degree of frum from 25% to 40%, resulted the rolling mode of motion for all of seeds began and end sooner.

The relationships between the density of the biomass pellet and the related variables are very complicated and highly nonlinear, which make developing a single, general, and accurate mathematical model almost impossible. One of the most appropriate methods to solve these problems is the intelligent method. Shankar and Bandyopadhyay and Shankar et al. successfully used genetic algorithms and artificial neural networks to understand and optimize an extrusion process.

The results showed that a four-layer perceptron network with training algorithm of back propagation, hyperbolic tangential activation function, and Delta training rule with ten neurons in the first hidden layer and four neurons in the second hidden layer had the best performance for the prediction of pellet density. The minimum root mean square error and coefficient of determination for the multilayer perceptron network were 0.01732 and 0.972, respectively. Also, the results of statistical analysis indicate that moisture content, speed of piston, and particle size significantly affected (P < 0.01) the density of pellets while the influence of die length was negligible (P > 0.05).

The results indicate that a properly trained neural network can be used to predict effect of input variable on pellet density. The ANN model was found to have higher predictive capability than the statistical model.

Exergy analysis is one method for studying of energy efficiency and optimization for systems and machines including dryers. Fluidized bed dryers despite widespread usage have low energy efficiency. Therefore a new method has been proposed that the fluid bed drying has been combined with thick (fix) bed dryer as outlet air from the fluidized bed section is conducted to the thick bed section for drying the other material or same kind material that existed in the first section. Experiments were performed in three temperatures, 50, 60 and 70 °C and three bed depth in down, fluidized bed drying, 4, 6 and 8 cm and two beds depth in up, batch bed drying, 6 and 8 cm. The results show that exergy loss of top floor is lower than down floor. And also increasing in bed depth of down floor causes increasing in exergy loss of top floor, but exergy loss of down floor decreases with increasing in bed depth of top floor.

Limitation of fossil fuels and the growing awareness of the detrimental environmental consequences resulting from greenhouse gas emissions have reinforced the importance of biomass as an energy resource. The conversion of rice straw and rice bran into briquettes as solid fuel is an important issue. The aim of this study was to determine the physical and chemical properties of rice straw and rice bran, and also the energy required for milling rice straw by hammer mill. Particle size distribution and particle density were determined for the milled straws, produced by four sizes of hammer mill screens at six particle size levels. FTIR test was carried out for determination of rice straw factor groups and distinction relation test. The required energy for grinding decreased with increasing of moisture content of the materials and the size of hammer mill screen. Normal distribution was observed for particle sizes of rice straw, grinded at 2 and 4 mm hammer mill screen sizes. The friction angle and bulk density of rice straw decreased with increasing the rice straw particle size. For the friction surfaces, the highest and lowest friction angles belonged to iron and aluminum surfaces, respectively. Based on the results of FTIR, during the burning process, lignin was fully destroyed in the oxidation reaction.