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Aims: Dust phenomenon is one of the natural hazards affecting the arid and semi-arid regions of Iran. It carries large amounts of particulate matter, which have dangerous impacts on human health, environment and vegetation. Therefore, dust is considered as one of the most important environmental problems that have drastically increased in recent times. Recognizing the origin and size of these particles, their chemical and physical properties and their elements are important for controlling and evaluating their effects on human health and the environment.
Materials & Methods: The Kermanshah province is located in the west of Iran and is one of the provinces that receive the most exposure to dust storms. For this investigation, four cities that are exposed to dust were selected: Sar-Pul-e-Zahab (SZ), Gilan-e-Gharb (GG), Islamabad (IA) and Kermanshah (K). For the installation of marble sediment traps in the Kermanshah province, 36 areas were selected. After collecting dust samples, particle size distribution analyses were conducted by using laser size analysis techniques. Chemical compositions were measured with the help of different techniques such as x-ray fluorescence and x-ray diffraction.
Findings: The results showed that the sizes of dust particles varied from 0.0004 to 112 microns, putting them in the range of clay and silt. The particle size in Gilan-e-Gharb was 0.04 to 0.45, Sar-Pul-e-Zahab was 0.04 to 112, Kermanshah 0.04 to 90 and Islamabad 0.0004 to 10 microns. The mineralogical composition of the dust particles mainly constituted quartz, calcite, muscovite, plagioclase feldspar, dolomite and vermiculite. X-ray spectroscopy studies on the dust particles generally showed the presence of aluminum oxide (Al₂O₃), silicon oxide (SiO₂), calcium oxide (CaO), iron oxide (Fe₂O₃), strontium oxide (SrO) and zinc oxide (ZnO).
Conclusion: In total, the results of this research work show that SrO, ZnO, silicon, aluminum, calcite, iron and their mineralogical compositions are the main oxides and elements in the dust of the Kermanshah province. Furthermore, the predominance of particle sizes in the range of clay and silt suggests that particles have been transmitted from medium to far distances alongside hinting at a similarity in their sources.

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The selection of a growing medium is one of the most important decisions in the culture of hydroponic crops. In order to select a suitable medium for hydroponic cucumber (Cucumis sativus L. cv. Negin), an experiment was carried out on growing media containing different particle sizes of perlite and organic substrates in a run-to-waste system in a greenhouse experiment. The growing media tested were: very course perlite (VC-P, 70% by volume in the range of 2-3 mm), course perlite (C-P, 70% by volume in the range of 1-2 mm), medium perlite (M-P, 70% by volume in the range of 1 mm), fine perlite (F-P, 70% by volume in the range of 0.5-1 mm), very fine perlite (VF-P, 70% by volume < 0.5 mm), sawdust (Sd) (100%), one mixture of VC-P and Sd (50:50, v/v), one mixture of VC-P and poplar chip (Ch) (50:50, v/v) and one mixture of VC-P and wheat straw (St) (50:50, v/v). The eight treatments were arranged in a randomized complete block design with four replications. The results showed that there were significantly differences in the mean fruit weight, plant height, and leaf area of cucumber with respect to media containing very course (VC)-grade perlite (horticulture-grade perlite) and its incorporation with organic substrates, and media containing different grades of perlite (from very course to very fine-grade perlite). The incorporation of wheat straw (50:50) into VC-grade perlite brought decreases of about 35% in the mean fruit weight of cucumber, respectively. Media containing fine grade-perlite led to a significant increase in mean fruit weight (50%), plant height (25%), and leaf area (70%) of cucumber as compared with media consisting of very course-grade perlite. It was concluded that the medium containing fine-grade perlite had the best performance for cucumber plant growth.

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 In the current study, fish-isolated protein (FPI) was extracted by alkaline pH method from the wastes of the head and fins of Siberian sturgeon (Acipenser baerii) and Iranian sturgeon (Acipenser persicus) and its composition, functional and structural characteristics were investigated. The results showed that the extraction efficiency according to the wet weight, the protein recovery of FPI, and the dry matter recovery of FPI from the Siberian sturgeon was higher than that of Iranian sturgeon. The results showed 91-94% protein in FPI of two species. The results did not show any significant differences between the proximate analysis and TVB-N (P> 0.05). The water absorption capacity, foaming capacity, and stability of FPI were shown at 30, 50, and 50%, respectively. The whiteness and transparency index of the FPI extracted was low. The results of particle size and zeta potential (P< 0.05) showed that the size of FPI particles in both samples is about a micron and they have a negative charge, so they can be easily used in colloidal systems. FTIR spectroscopy in both samples showed all the absorption peaks related to the main bonds of the protein structure. In general, considering the large amount of sturgeon waste in processing, and the amount of protein, functional properties, and nutritional value of FPI extracted from two species of sturgeon, there is the possibility of using them in human food and sports supplements.

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Molten dark chocolate is a dispersion of solid particles including sugar and cocoa powder in a continuous phase of cocoa butter. Hence, the rheological properties as well as the particle size distribution of ingredients in chocolate are very important for obtaining high-quality products with well-defined texture. Therefore, the present study aimed to evaluate the effects of sugar substitutes on rheological characteristics and particle size distribution of prebiotic dark chocolate. For doing this, a prebiotic compound (inulin) in combination with bulking agents (polydextrose and maltodextrin) at different levels (0–100 %) along with sucralose were used. Based on our findings, all the treateded samples showed thixotropic and pseudoplastic behavior and the Casson mathematical model most closely fitted to the rheological data. Furthermore, the sucrose replacement slightly affected the viscoelastic properties and the viscosity of the samples was time independent. In terms of the particle size, they were somewhat larger than the commercial one but still below the taste threshold.

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Wheat germ, a highly nutritive part of wheat kernels, is separated during milling as a by-product. In this study, wheat germ was used to supplement cakes. Different levels of the germ (0, 5, 10, 15 and 20%) at different particles sizes (280, 585, 890 and 1,195 µm) were added to a cake recipe. The results showed that with increasing the germ level and particle size, batter consistency and density of the cakes increased significantly, while the height of the cakes decreased. With increasing the germ level and its particle size, the crumb became slightly yellow while the crust color and the textural parameters (TPA test) remained unaffected. Determination of the sensory attributes of the samples showed that the particle size was negatively correlated with the crumb color and texture of the cakes, while other sensory parameters remained unaffected. In general, 15% of germ was the highest level and 280 µm was the most suitable particle size (as recognized by the panelists) for the production of an appropriate germ cake.

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Soil erosion causes sediments to be detached from their source materials and transported as suspended particles. The present study was conducted to evaluate the effects of sand exploitation on the distribution of suspended sediments in the Educational and Research Forest Watershed of Tarbiat Modares University, which comprises approximately 50,000 ha. Fifty-one water samples were collected before and after sand mining between November 2007 and June 2008. The settling rates of the primary particles of suspended sediments were then analyzed based on the principle of sedimentation described by Stokes’ law and using the modified pipette technique. Analyses of the samples indicated that the Suspended Sediment Particle Size Distribution (SSPSD) was significantly affected by sand mining. Specifically, an independent samples T-test demonstrated that the mean contents of sand, silt and SSC during and after sand mining differed significantly (P< 0.01), with respective values of 74.19±13.4 and 9.75±13.8, 81.77±4.5 and 2.96±2.7% and, 7.66±7.7 and 0.34±0.3 g l^-1 being observed. Additionally, no significant difference was found between data sets collected before and during sand mining for hydrologic and SSPSD characteristics at 1%, which clearly proved consequent effects of sand mining on SSPSD.

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Rheological properties of chocolate are important in manufacturing process for obtaining high-quality products with well-defined texture and are directly influenced by composition and their refining time. Soy protein benefits from nutritional and functional properties to be used in different foods. Effects of different replacement levels of skim milk powder by soy flour, (from 0 to 100%) and ball mill refining time (105 and 135 minutes) on particle size and rheological properties of compound chocolate were investigated. Considering four rheological models, it was found that compound chocolate behaved as a Casson fluid .Overall, the results indicated that Casson plastic viscosity values ranged between 1.36 and 5.47 (Pa s) and replacing skim milk powder with soy flour led to a significant (P< 0.05) increase in Casson plastic viscosity in either of the refining time treatments. Casson plastic viscosity and apparent viscosity also increased for all the replacement levels with increase in refining time from 105 to 135 minutes. Values of Casson yield ranged from 11.23 to 38.88 (Pa). By replacing soy flour, Casson yield value increased significantly (P<0.05). Casson yield value also increased with increase in refining time in samples containing only skim milk powder, but it decreased in samples containing soy flour.

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Due to the positive effects of fiber on human health, production and distribution of high fiber containing foods is on the increase. Amongst different foods, bread is a suitable option to convey fiber in human diets. Flat breads which are very common in Asian countries, are mainly produced from white flour and hence are low in fiber. The main objectives followed in this study were to produce high fiber Barbari bread (a popular flat bread) using wheat bran, while minimizing the adverse effects of inclusion of bran in the bread recipe. To achieve this, wheat bran of different levels (0-20%, w/w flour basis) and particle sizes (170, 280, 425 and 750 mm) were added to Barbari bread recipe. Using Brabender Farinograph, it was found that with increase in bran level and its particle size, the water absorption of the dough increased. Color determination results showed that the bread crust color became darker as the level of the bran and its particle size increased. The results of determination of the bread texture using Texture Profile Analyser, showed that the bread became harder and less cohesive with increase of the fiber in the dough and for each bran particle size. According to the panelists, barbari breads constituted the most appropriate breads with up to 15% bran with particle sizes of shorter than 280 mm. In total, it was concluded that by a control of the level and particle size of the bran, it is possible to increase the fiber content of the bread without any significant adverse effects on the quality.

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An experimental and numerical approach on crack propagation and fracture toughness of Central Straight-through Crack Brazilian Disk (CSCBD) samples under compression is carried out to be investigated the effect of particle size heterogeneity. To accomplish this goal, six type of specimens with different silica sand particle size but same combination are used for preparation CSCBD specimens. Diametrical compression load with a rate of 0.3 mm/min in two directions respect to the central crack orientation is applied to the discs and the failure loads corresponding to the each test are recorded. Also In this study, a numerical simulator based on RFPA (Rock Failure Process Analysis) is used to study the crack propagation path and fracture load in simulated CSCBD specimens with different particle size (Similar laboratory specimens). In this simulator, the heterogeneity of specimens is considered by assuming that the material properties of elements conform to a weibull distribution. Result of laboratory tests indicates a nonlinear relation between specimen’s particle size and mode I and mode II fracture toughness. The specimen whit medial particle size (2-2.38 mm) has the maximum fracture toughness in two fracture mode. Toughness of specimens decreased with increase and decrease of silica sand particle size. Numerical results shows, the trajectory of crack path for fine particle are more regular and initiated from the crack tip, propagate parallel to the load direction. But it’s for coarse particle, initiated from the boundary of grains in whole of the specimen and lead it to failure in an unexpected path. An experimental and numerical approach on crack propagation and fracture toughness of Central Straight-through Crack Brazilian Disk (CSCBD) samples under compression is carried out to be investigated the effect of particle size heterogeneity. To accomplish this goal, six type of specimens with different silica sand particle size but same combination are used for preparation CSCBD specimens. Diametrical compression load with a rate of 0.3 mm/min in two directions respect to the central crack orientation is applied to the discs and the failure loads corresponding to the each test are recorded. Also In this study, a numerical simulator based on RFPA (Rock Failure Process Analysis) is used to study the crack propagation path and fracture load in simulated CSCBD specimens with different particle size (Similar laboratory specimens). In this simulator, the heterogeneity of specimens is considered by assuming that the material properties of elements conform to a weibull distribution. Result of laboratory tests indicates a nonlinear relation between specimen’s particle size and mode I and mode II fracture toughness. The specimen whit medial particle size (2-2.38 mm) has the maximum fracture toughness in two fracture mode. Toughness of specimens decreased with increase and decrease of silica sand particle size. Numerical results shows, the trajectory of crack path for fine particle are more regular and initiated from the crack tip, propagate parallel to the load direction. But it’s for coarse particle, initiated from the boundary of grains in whole of the specimen and lead it to failure in an unexpected path.

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Rice bran is a major by-product of the rice milling process that contains high amounts of fiber, proteins, fats, vitamins, minerals as well as antioxidants and hence can be utilized in enriching food products. The main aim followed in this study was to determine the effects of rice bran of variable particle sizes (53, 125 and 210 µm) and its quantity (0, 5, 10, 15 and 20%) on the quality of batter and on sponge cake. Increasing bran quantity and particle size increased batter density and consistency. Using a higher quantity of bran with larger particle sizes increased cake density and weight of the cakes (after being baked) while decreasing the cake volume. Textural properties of the samples as determined instrumentally showed that maximum compressive force and the firmness increased, while cohesiveness and springiness decreased with increase in the contents of bran and increase in its particle size. Cake crust color became darker, more reddish and less yellowish with inclusion of rice bran. Increasing the levels of rice bran, negatively affected taste, crust and crumb color as confirmed by the sensory panel. Overall, it was found that addition of 10% rice bran with particle size of 125 µm resulted in the most desirable cake quality.

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Complex coacervation is generated through electrostatic interaction between oppositely charged biopolymers (proteins and polysaccharides). Complexation via electrostatic interactions can lead to formation of soluble or insoluble complexes. In the current research, the production and characteristics of the complexes formed from whey protein concentrate (WPC) and gum tragacanth (GT) were evaluated. In order to find the optimum pH for complexation, absorbance of protein-polysaccharide mixtures were measured at a wide range of pH (2–8), Furthermore, particle size, zeta potential, microstructure and rheological properties of the complexes were investigated. Based on the results, the best condition to form complex between WPC and GT was found to be at pH=4.5. With Increasing the amount of GT up to 0.75% w/w in a constant protein concentration (0.5% w/w), the lowest and highest particle size for WPC- GT complex was found at protein: polysaccharide ratio of 1: 1 (3018 nm) and 10:1 (4070 nm), respectively. Zeta potential changed from +3.11 mV (0% gum tragacanth) to -6.82 mV due to addition of GT (0.75% w/w). Microscopic images showed the presence of separate spherical particles, except at the concentration of 0.05% w/w. The appropriate rheological model to predict flow behavior of complexes was depended on protein-polysaccharide ratio and the dominate flow behavior index was found to be shear thinning. Increasing of TG concentration lead to lower flow behavior index as well as higher apparent viscosity, consistency coefficient and the yield stress

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Physicochemical and mechanical properties of wheat grains can have a great impact on the quality of the final products (bread). Therefore, correct selection of wheat cultivar for specific applications seems to be crucial. In this study, the differences in the physicochemical and mechanical properties (under compression and impact loadings) of ten Iranian wheat cultivars (Azar2, Alamut, Bam, Bahar, Chamran, Shiraz, Falat, Keras Adl, Marvdasht, and Nicknejad) were studied. Moreover, the relationship between these properties was investigated. The results indicated that the type of cultivar had significant influences on physicochemical and mechanical properties. The results of regression analysis between physicochemical and mechanical properties showed a significant correlation between protein content and particle size index (r²= 0.6). Moreover, the protein content could be significantly correlated with the parameters obtained from mechanical tests (r²> 0.50). Among the mechanical parameters obtained from compression and impact loading, the apparent elastic modulus and the specific breakage energy established maximum correlation (r²= 0.77 and 0.78, respectively) with the protein content. Similarly, significant correlations were found between particle size index and mechanical parameters (r²>0.60). Hence, the wheat protein content and particle size index, which have great impacts on quality of the final product, can be estimated by a few simple mechanical tests on the wheat kernels. 

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Rotational abrasive flow machining process (RAFM) is one of the modern surface polishing processes where in the material removal in micro and nano sizes is performed by tiny abrasive particles. Rotational abrasive flow machining is very effective in finishing of complex internal and external surfaces.in comparison with other finishing methods. In this study, the rotational abrasive flow machining process has been investigated in polishing of AISI H 13 hot work steel. The main objectives of workpiece rotation was increasing the material removal rate and decreasing the surface roughness of workpiece. So the effects of rotational speed and hardness of workpiece and the mesh size of abrasive particles as input variables on the output parameters including surface roughness and material removal rate have been studied. The results showed that applying of rotational speed of workpiece leads to higher material removal rate and lower surface roughness. Furthermore, the material removal rate is decreased and surface roughness is improved by increasing the mesh size of abrasive particles. Also, increasing the hardness of workpiece leads to decreasing the material removal rate, and in similar cutting conditions, the surface of workpiece with more hardness is better polished in comparison with the surface of workpiece with lower hardness.

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In this study, the effect of low methoxyl pectin addition oi the three levels including 0.2, 0.4 and 0.6% on the structural properties of cream with 45% fat globules was investigated. Structural study of the dispersed phase was performed using particle size distribution method and the morphological properties evaluated by optical microscopic images. The results show the effectiveness of low methoxyl pectin on the size distribution of fat globules in the cream. The mean volume-surface of ​​fat globules in pectin-free cream increased from 2.28 to 4.65 μm in the sample with 0.6% low methoxyl pectin. Optical microscopic images demonstrated the morphological of fat globules change from spherical and solitary to the agglomerated form. On the other hand, increasing of low methoxyl pectin levels caused to increase the irregularity of particles size distribution in the images obtained from microscopic observation. Fractal dimension was calculated as an indicator for complexity quantification based on microscopic images. An increase in fractal parameter observed with increasing levels of low methoxyl pectin in the cream. On the other hand, a relationship with high coefficient of determination was observed between the changes in particle size and fractal dimension.

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This study was conducted with two consequential experiments to investigate the effect of magnetized water on in-vitro limestone solubility and eggshell breaking strength in laying hens. The first experiment was conducted to investigate the effect of magnetized water and particle size on in-vitro limestone solubility. Three particle sizes including small particles, less than 0.125 mm; large particles, 2-4 mm and normal mix, 0.045-4.00 mm were tested. Magnetized water was generated by magnetizer of 0.65 Tesla magnetic fields. Scanning Electron Microscopy images (SEMi) were used to study the morphology of limestone crystals after dissolution in magnetized and tap water. Limestone solubility was measured by 0.2N HCl solution. The second in- vivo experiment was conducted to study the effect of magnetized water and dietary calcium on breaking strength of eggshell. Three dietary levels of calcium and phosphorus (normal, 10 and 20% reduced Ca and available P.) and two types of water (tap water and magnetized water) were used in Hy-line laying hens at 32 weeks of age. Breaking strength of the normal (safe and sound) eggs was measured with an Instron testing machine. The solubility of large limestone particles was less than those of small particles. Magnetically treated water did not change in-vitro limestone solubility but changed the morphology of limestone crystals. Precipitated limestone crystals in magnetized water tended to be larger and more uniform in size than those in tap water. Reducing dietary levels of Ca and P had no significant effect on egg breaking strength at 36 weeks of age. Magnetized water was able to numerically increase strength of the eggs. Therefore, based on the SEMi and the observed changes in crystalline structure of dissolved (exposed to water) precipitated limestone and observed changes in breaking strength of the eggs, it is hypothesized that magnetized water may have the potential to change the limestone availability and consequently egg strength in laying hens.

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The aim of this study was the production of double emulsions stabilized by hydroxypropyl methylcellulose and comparison of physicochemical properties of these emulsions with double emulsions stabilized by Tween 80 emulsifier. Double emulsions were produced using the two-step method. Firstly, an initial water-in-oil (W/O) emulsion was prepared by adding 20% ​​of the internal aqueous phase containing sodium chloride to the oil phase containing 95% sunflower oil and 5% Polyglycerol polyricinoleate (PGPR) and mixing with a magnetic stirrer. In the second stage of emulsification, 40% of the initial water-in-oil (W/O) emulsion produced in the first stage was added to 60% of the external aqueous phase containing hydroxypropyl methyl cellulose emulsifier in three levels of 2, 3 and 4%, 1% hydroxypropyl methyl cellulose and 1% tween 80 and 2% tween 80 as control sample and dispersed by magnetic stirrer. Both the produced emulsions were homogenized using a high speed homogenizer for 15 minutes at 15000 rpm. The produced double emulsions were optimized in terms of particle size and distribution, stability, viscosity, color and morphology. The results showed that the lowest particle size was related to the double emulsions produced by Tween 80 which their particles size and distribution were 385.33 nm and 0.31, respectively. These parameters were 453.97 nm and 0.33, respectively for emulsions stabilized with 4% hydroxypropyl methyl cellulose.

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Solid lipid nanoparticles (SLN) are one of the appropriate delivery systems which attract enormous interest for encapsulating bioactive componds in recent years. One of the important physicochemical properties of SLNs is particle size that is influenced by formulation and production process parameters. Inappropriate conditions of the nanaocarrier production process in the pre and main emulsion steps cause unsuitable paricle size as well as unstable emulsion and gel formation. Therefore, in this research production process of SLN was investigated and optimized by hot homogenization method and with two lipids of Compritol and Precirol separately. Hence, homogenization time in preparation of pre emulsion and amplitude and time of ultrasonication in final emulsion production was studied to obtained the smallest particle size. In pre emulsion step, the smallest particle size for Compritol SLN (619±4 nm) and Precirol SLN (373±3 nm) obtained in 180 second mixing by ultra-turax in 16000 (rpm). In final emulsion, 40% amplitude and 3 minutes caused to attained smallest particle size in Compritol SLN (397±5 nm) and Precirol SLN (259±2 nm). Then polydispersity index (PDI), zeta potential and visual observation of nanocarriers with optimized particle size were examined. The results showed that Precirol SLN had higher zata potential (-12.3±0.6 mV) than Compritol SLN (-8.97±0.17mV) but PDI of two nanocarriers was not significantly different. Visual observation of both nanocarriers at the storage time showed no instability.