محمد فیاض

The phenomenon of dust storms has become a global environmental challenge. As a natural disaster, it has significantly affected Khuzestan province due to its geographical location and proximity to vast desert areas. This study aims to examine land management strategies to mitigate dust production in the southeastern dust source of Ahvaz by implementing effective land management techniques to control wind erosion in this region.

To conduct this research, ecological land resources—including climate, geology, soil properties, land use, vegetation cover, wind erosion, and agricultural and livestock conditions were analyzed using satellite imagery and extensive field surveys. By overlaying maps, the dust source area was classified into ecologically homogeneous units (work units). Based on the physical and chemical properties of the soil, the vegetative potential for biological stabilization was determined according to the ecological requirements of native plant species. Soil samples were collected from 106 points at three depths, and soil erodibility was assessed using a wind tunnel. A wind erosion sensitivity map was then generated to prioritize the stabilization of work units. The characteristics of erosive winds were analyzed using hourly wind speed and direction data from 21 meteorological stations. After creating a database of ecological resources in a GIS environment, the vegetative potential of the work units was evaluated using soil properties. Subsequently, specific stabilization projects were proposed for each work unit.

The findings of this study indicate that the stabilization strategy was planned systematically, considering the ecosystem type, and dust control projects were designed based on land use classifications. The land use distribution of the dust source area includes 37% rangelands, 10% bare lands, 11% dried wetlands, 24% rainfed agriculture, and 13% irrigated agriculture. The proposed projects included biological measures such as shrub planting, afforestation, roadside tree planting, and living windbreaks along farm edges, as well as management strategies such as soil moistening, leaching, irrigation, grazing control, construction of non-living windbreaks, and rainwater harvesting techniques. Analysis of the energy trend of erosive winds over the past decade revealed no significant changes. Instead, the activation of dust sources was attributed to land use changes, precipitation patterns, and drought occurrences.

The lack of water allocation to downstream ecosystems, combined with the construction of large dams and multiple watershed management structures in upstream areas, has led to the transformation of wetlands and sedimentary plains into major dust sources and has contributed to surface soil salinization. Restoring flood capacity in these areas was achieved through the construction of water supply channels to meet the water demands of biological stabilization projects and facilitate the moistening of wind erosion-sensitive units. Overall, the implementation of these projects demonstrated that this ecosystem restoration-based approach, with a focus on wind erosion-prone lands, can serve as an effective model for stabilizing the country’s dust source areas.

Improving the mechanical characteristics of concrete especially its tensile, bending and impact resistance, has long been the focus of various researchers. In this research, the effect of adding different steel fibers along with polypropylene fibers in different dimensional ratios together with commonly used mineral additives to improve the impact resistance of concrete has been investigated. The considered parameters included the percentage of polypropylene and steel fibers, the ratio of length to diameter of steel fibers (L/D), the percentage of fly ash, microsilica and epoxy additives, and the age of specimen. Experiments aimed at determining the impact, tensile, bending and compressive strength of the studied concrete specimens were carried out. To determine the impact resistance, a new laboratory method was introduced and used. The results of the strength of concrete specimens at different ages of 7, 28 and 90 days show the significant effect of the use of hybrid fibers on increasing the tensile and impact resistance and somewhat weaker on the compressive and bending strength of concrete. It was also observed that the use of mineral additives has a greater effect on increasing the flexural strength of concrete than adding fibers. Comparison of specimens with various L/D ratios of metal fibers showed that fibers with lower L/D ratios result in greater improvement of the mechanical properties of concrete. Finally, the positive effect of the simultaneous use of hybrid fibers with optimal L/D and mineral additives on the mechanical characteristics and especially the impact resistance of concrete was investigated.

Concrete canvas is a composite material made with three-dimensional spacer fabric, which is manufactured by impregnating the fabric with cementitious materials. Concrete canvas has weaknesses in its mechanical properties including tensile strength. Strengthening concrete canvas with Fiber-reinforced polymer (FRP) materials can effectively improve its mechanical properties, particularly its tensile strength. Therefore, this study focuses on examining the impact of using FRP polymers to enhance the tensile properties of concrete canvas. Three types of fibers, namely Glass Fiber Reinforced Polymer (GFRP), Carbon Fiber Reinforced Polymer (CFRP) and Aramid Fiber Reinforced Polymer (AFRP; known as a Kevlar fiber) in various layer configurations, both warp and weft, were utilized to reinforce concrete canvas under tensile loading. The test results demonstrate that the use of FRP fibers significantly enhances the mechanical properties of concrete canvas. Specifically, single-layer glass fibers lead to considerable growth and reinforcement with carbon and Kevlar fiber layers results in more than five to seven times improvement in tensile strength compared to control concrete canvas.

In recent years, due to the high costs of pavement construction and environmental considerations, various recycled materials have been used in the roller compacted concrete pavements. On the other hand, due to the increase in the price of bitumen in flexible pavements, the use of roller concrete in the construction of pavements seems to be more economical. In this research, the mechanical properties, abrasion resistance and impact resistance of rolled compacted concrete containing recycled asphalt and fly ash have been investigated. A total of 15 mixture design were studied with replacement amounts of 10%, 20% and 30% of fly ash as a substitute for cement and 5%, 10% and 15% of fine-grained recycled asphalt as a substitute for aggregate. In order to determine the optimal amount of fly ash, first, compressive and bending strength tests were performed on 7-day samples containing 10%, 20% and 30% of fly ash, and the optimal percentage was obtained. Therefore, in mixtures 4 to 6, the amount of fly ash to replace cement for all mixtures was considered the optimal value (10%). It should be noted that for more accuracy, the 28-day samples containing different amounts of fly ash were also examined. Results of this research showed that the use of fine-grained recycled materials at the rate of 5%, 10% and 15% along with 10% of fly ash led to an increase in compressive strength by 20%, 12% and 4%, bending strength by an average of 10% and tensile strength on the average is about 40% compared to control sample. However, all samples containing recycled asphalt have shown a significant decrease in abrasion resistance.

Earthquakes in many parts of the world cause the collapse of buildings and the occurrence of damages and the resulting dangers; Therefore, it is necessary to assess the risk of the buildings and, if necessary, improve or retrofit them. In addition to earthquakes, other natural hazards such as floods and storms, as well as unnatural hazards such as explosions, chemical attacks, and fires may also threaten a building; Therefore, it is necessary to consider all the different aspects of the building's vulnerability in its risk assessment. Evaluation of structures is done in two fast (qualitative) and quantitative (analytical) methods. In qualitative evaluation methods, in a short period of time, buildings are quickly evaluated and classified in terms of vulnerability. In this research, a variety of quick risk calculation methods have been  investigated. The integrated rapid visual survey IRVS method, which has the ability to calculate risk and resilience for all types of man-made threats and natural hazards, has been developed for the domestic conditions of the country, and its Persian software is written using the Python programming language. Read Excel. It also has the ability to offer options to reduce risk according to the user's desired risk.

Nowadays, concrete roll is used in various fields of civil engineering and architecture. Therefore, improving the mechanical properties of this product is important in order to increase the scope of its using. In this study, the effect of yarn and weave of 3-D spacer fabric was investigated on flexural and tensile strengths of concrete roll. For this purpose, four samples of 3-D spacer fabrics with different yarns and weaves were prepared and the cement was injected into these samples. After hydration of concrete roll, the initial cracking stress, final stress and tensile strength were obtained. The results showed that the number of spacer yarns has a significant effect on the amount of initial cracking stress, and the final stress of flexural strength is also increased almost with increasing the initial cracking stress. The results also showed that the type of yarn used in the 3-D spacer fabric has a significant effect on the tensile strength. The tensile strength of concrete roll is increased with increasing the capillary ability of the samples, due to the better hydration of concrete.

By adding fibers as well as additional materials in concrete, the properties of concrete can be increased in terms of durability, flexibility and tensile strength. Another use of artificial fibers to improve mechanical properties and reduce shrinkage of fresh and hardened concrete, increase energy absorption and resistance to impact and explosion can be mentioned. The use of fiber concrete has many advantages compared to the use of reinforced concrete, while it also has disadvantages, such as the lack of uniform distribution of fibers in the concrete matrix and the lack of proper adhesion between polymer fibers in cement mortar. Generally, fiber concrete is used in concrete parts due to smaller cracks and less width and more durability in case of uniform distribution of fibers. Research shows that fibers significantly increase the tensile strength, plasticity of mortar and concrete. In fact, after cracking, the fibers bridge between the crack plates and cause a significant increase in toughness and energy absorption capacity. Adding artificial fibers to concrete brings advantages such as reducing plastic grip cracks, reducing plastic drop cracks, increasing impact resistance and increasing resistance to crushing. In this research, the effect of different types of fibers with different volume percentages on the compressive, bending and tensile strength of the samples at different ages compared to the control sample has been measured by laboratory method. All kinds of samples have been tested to determine the resistance against surface explosions.

Severe hydraulic gradients in open channels cause severe bed erosion and problems caused by sedimentation. Fabric concrete is a unique product with high execution speed that can replace traditional concrete surfaces. According to the mechanical resistance parameters of this product, in addition to its good durability against corrosive factors, one of the applications of fabric concrete is its use on the surface of canals and water course culverts. In this research, first, the flow of open channels in trapezoidal section is simulated under 9 scenarios, which include 3 common channel geometries in the state of a straight path, a path with bends and deviations, and finally, a channel path with a change in height at the bottom of the channel. In each of the states, 3 different flow regimes have been investigated along with flow turbulence modeling using flow-3d software.Different flow regimes have been investigated along with flow turbulence modeling using flow-3d software. Using ABAQUS software, fabric concrete components and their connection areas have been modeled, and by applying forces equated to the concrete surface and vulnerable connection areas, the amount of created stresses has been checked. The results show that the created stresses are very low compared to the tensile and compressive stress capacity of fabric concrete. In order to validate the hydraulic studies of flow and concrete, the relevant laboratory results have been used.

The retrofitting plan is effective when, in addition to being cost-effective, it minimizes casualties, reduces infrastructure damage, and limits the extent and scope of damages as much as possible. The design and construction of most explosion-resistant barriers in all types of structures are not optimal due to the high cost on the one hand and the low probability of explosion during the life of the structure on the other hand. In this research, the proposal of using the combined method of restraining net along with the blast wave absorber panel as a new model in protecting the building against external explosions has been studied. The rocket is restrained at a certain distance from the main structure by a resistant net and the panel absorbs the wave caused by the explosion. By conducting studies and experiments on various absorbent materials, the selected panel was introduced and its behavior against threats at different distances was evaluated numerically and in the field. The results of the simulations were in good agreement with the field tests, which can be generalized for different amounts of charge.

In order to determinating of the grazing behavior tali goat as dominant livestock, this investigation was done from 2007 for 4 years in Sirik rangeland of Hormozgan province. Parameters examined in this study included time arrival and departure of livestock from pastures, daily distance traveled by livestock, livestock path in the rangeland considering the slope, livestock speed (mean and maximum) and the time spent for livestock rest, grazing and movement per day. To determine the parameters, Garmin GPS was used on the back of a 4- year-old ewe using a special belt. After livestock exit from the fold, GPS was active and at the end of the day all recorded data were extracted by Mod-track in Ilwis software. The livestock path was determined by shepherd. The results of livestock grazing behavior in the months of the grazing season for the four years studied showed that there was a significant difference between average mileage and grazing time in different years and for the months of the grazing season, all behaviors except mileage. The average speed of livestock was 2.65 km / h, the distance traveled was 12.8 km and the grazing time was 4 hours and 49 minutes. Also, during the study years, 44 to 45% of the time when livestock was moving in the pasture was dedicated to grazing. It is worth mentioning that the information extracted from the correlation of GPS livestock route map with the slope map of the region showed that in all five months during the years under review, all distance traveled by livestock is in the slope class of 0-8%.

The concrete canvas product consists of three main parts: the three-dimensional (3D) substrate with the cement mixture, the geo-membrane layer and the desired adhesive to connect the geo-membrane layer to the three-dimensional substrate. The three-dimensional layer is generally made of polyester, polypropylene and other engineered polymer had good mechanical and chemical properties, and has different thicknesses, suitable for various applications. This three-dimensional layer is designed in such a way that it has different textures on both sides so that the cement is poured into the space of the three-dimensional layer on one side and nothing spills out of the other layer. In the next step, this process is completed by connecting the geo-membrane layer to it. In industrial application; the geo-membrane layer formulation (including polymer-based resin, emollient, impact curing, filler, etc.) is designed in such a way that in addition to moisture insulation properties, mechanical strength and good chemical resistance to moisture dilute alkaline and acidic environments. In this way, a desired adhesive with desired formulation (including adhesive base resin, solvent, activator and type of catalytic additive, etc.) was selected for connecting of geo-membrane to 3D substrate. To achieve a suitable product, in addition to the geo-membrane layer, the adhesive selected to connect the geo-membrane layer to the three-dimensional substrate must have the appropriate viscosity to be able to completely cover the three-dimensional substrate and cause the two layers to be fully connected to each other. . If the adhesive used cannot create a suitable coating on the geo-membrane layer, by penetrating the fluid around the adhesive, it will weaken and thus destroy the entire coating layer and thus separate the layered concrete layers. In this way, one of the main disadvantages of concrete canvas produced by conventional methods is the separation/layering of the coating layer from the concrete canvas substrate due to thermal and mechanical stress, which weakens the adhesive connecting the layer to the substrate which creates practical problem for this product. In this work, the polymer casting technology based on polyvinyl chloride paste was used to cover a concrete canvas and the properties of the product were investigated. In this method, the polymer paste is coated on the three-dimensional substrate in one step without using (geo-membrane / adhesive) by Dr. Blade knife in a certain thickness. The results showed that the fabric concrete made based on the PVC paste casting method, has good sealing, mechanical and chemical resistance and has good resistance against layering. The results showed that the fabric concrete product obtained from the polymer casting method based on (resin / polyvinyl chloride paste) in terms of mechanical strength, showed acceptable properties compared to the geo-membrane layer and the overall fabric concrete product and also in terms of chemical properties (resistance to various solvents), it has a much better resistance than the sample made by conventional methods (geo-membrane / adhesive). This product (concrete canvas) has also shown better resistance to water leakage against the sealing of the product, the overall product made by the polymer casting method.

One of the important factors in determining the grazing capacity of rangelands is determining the preferred value of rangeland plants according to the type of livestock using the rangeland and its changes during the grazing season. In this study, the preference value of rangeland species in Zaminsang rangeland in Hormozgan province in the months of grazing season (January to May) and different years (2007-2010) was investigated. To determine the preference value, the method of utilization percentage of plant species and determination of preference index were used. The results were analyzed in a split plot statistical design in time in a randomized complete block design in SAS software and the statistical mean of the studied trait was compared with LSD test. The results showed that the most preferred livestock is primarily Aeluropus lagopoides and Atriplex leucoclada and Alhagi graecorum. The lowest percentage of exploitation was from Halocnemum strobilaceum and Desmostachya bipinnata. Based on the preference value index classification, Aeluropus lagopoides and Atriplex leucoclada species are relatively palatable species (relative preference), Alhagi graecorum and Halocnemum strobilaceum species are moderately palatable species (moderate preference) and Desmostachya bipinnata was one of the almost non-palatable (relative avoidance) species.

The main purpose of this study is to do modeling and investigate the relationship between liquidity and its role in the development of the stock and the housing market. This is accomplished through comparing 10 of Bayesian Averaging methods and principal component analysis carrying out an extensive set of simulation studies based closely on real datasets that span a range of situations encountered in practical data analysis. The data used in this article includes the seasonal data during the period from (1385:1) to (1399:4. The evaluation results show 4 types of PC, so that the first PC shows more than 95% of the changes. In the first PC, the two variables of liquidity and exchange rate have the most weight, and respectively, the second, third and fourth PC are related to oil revenues, legal deposit ratio and coin price. The variables of liquidity, exchange rate and oil revenues have a positive relationship with the index of stock and housing prices, and the variables of the legal deposit ratio and the price of coins have a negative relationship with the index of stock and housing prices. Also, the estimation results of the 10 analyzed models of Bayesian averaging show that in the modeling of the stock price index as well as the modeling of the housing price index, the best models are obtained through applying PCA and the prior distribution of AIC. Therefore, the use of the principal component analysis and the AIC model as a basis for approximating the probabilities of the posterior model, under the condition that the probabilities of the prior model are similar to Zellner's g-prior, is approved in this research.

One of the main challenges of conventional concrete canvas is the separation of the geo-membrane layer from the fabric concrete substrate, which has caused major problems in the discussion of the application of this product. In this work, the method of casting polymer paste based on acrylic resins was used to create a single-layer coating of sealing resin with the high overall mechanical strength of the product, and the properties of the product were investigated. In this method, polymer paste is formed in one step without the use of adhesive and geo-membrane layer on the three-dimensional substrate bed, and the overall productivity of concrete canvas is formed. The results showed that concrete canvas produced based on polymer paste casting method with suitable mechanical strength (30 (kN / mm2)), better sealing (up to 30 days without changing weight against water), non-layering, Suitable chemical resistance against hexane, toluene, benzene and octane and better temperature resistance (from -20 to 100 C) than conventional concrete canvas product.

Reaction time measures have considerable potential to aid neuropsychological assessment in a variety of healthcare settings. One such measure, the intra-individual reaction time variability is of particular interest as it is thought to reflect neurobiological disturbance. The present study aimed to investigate the intra-individual changes in reaction time to visual stimuli in dominant or non-dominant binocular and monocular vision.

This descriptive-analytical study was conducted on 12 volunteers with an average age of 30.08±1.448 years in 2021. The subjects consisted of the students and staff of Golestan University of Medical Sciences (5 female and 7 male). The reaction time was recorded automatically by the hand reaction time device of Danesh Salar Iranian Company based on the time of presentation of visual stimulation on the computer screen and the person's reaction, i.e. pressing the buttons of the handles by each of the two hands. All experiments were performed between 10 and 11 am and following at least 2 hours of fasting. Data collection was done following training trials for correct performance of the 2-choice reaction time test. After completing the reaction time tests for each volunteer, the dominant eye was determined by the hole-in-card method.

In 4 volunteers, the dominant eye was left and in the rest of the volunteers, the dominant eye was right. The dominant eye did not differ between men and women. The number of reaction times recorded in right monocular vision left monocular vision and binocular vision were 902, 911 and 893, respectively. The mean reaction time in right monocular vision, left monocular vision and binocular vision was 306.81±3.310, 304.28±3.339 and 312.95±4.569, respectively, and the range of reaction times in these three states was between 194-1750, 178-1587, and 155-1797 ms, respectively. Intra-individual reaction time variability in the dominant left eye and left hand were significantly lower compared to the dominant right eye and right hand, respectively (P<0.05). No difference was observed between the reaction time of the right monocular vision, left monocular vision, and binocular vision.

The alignment of the dominant left side in the eye and hand reacts faster than the dominant right side in the eye and hand. The mechanism of this phenomenon may be related to the overall process that determines the dominant left hemisphere in approximately 90% of the population.

Concrete canvas rolls have several unique properties have made it a strategic material. A major property is rapidness of installation that can be considered in the construction of accelerated shelters of protection against threats. The use of concrete canvas in the construction of the shelter is also expanding worldwide due to its economic benefits and the speed of its installation, as experience has shown that a two-person team can build a shelter with an area of 25 square meters of concrete canvas in less than an hour. Increasing attention to this function of concrete canvas requires studying product behavior against incoming loads, and the need for a deep understanding of the material and components of aerated concrete leads to a better understanding of this product and the possibility of improving product quality. Therefore, the properties of two-phase concrete canvas, including fabric and mortar that have structural performance, were studied using Abacus finite element software. The results of finite element simulation on macro and Meso scales were compared with the laboratory results of different samples, showing the accuracy of the study. The results illustrate that the use of fibers with higher tensile strength and high Young's modulus and stiffness has a better performance against the applied loads. The shelter behavior is evaluated against different probable attack scenarios. The designed shelter is capable of withstanding slag up to a height of 70 cm of soil, which also makes it resistant to mortar attacks. The use of a concrete canvas shelter without any slag also makes it resistant to the 5 kg TNT threat at a distance of 3 meters. Using products against larger threats or loads strengthens the shell with appropriate materials or several layers of concrete canvas shells.

Spiritual health is one of the four dimensions of human health and is an effective factor in promoting health. Sexual self - efficacy is associated with one's belief in th e ability to function effectively and adapt to their partner, a form of self - assessment and self - efficacy. The p urpose of this study was to investigate the correlation between spiritual health and sexual self - efficacy in pregnant women referring to Sananda j health centers in 2019 .

Methods :

The current study is descriptive c ross - sectional. The statistical population of the study included pregnant women referring to health/ treatment centers in Sanandaj (28 centers and 35 bases) in 2018. The sample size, as c alculated based on Cochran's formula, was 384 people, who were randomly selected by random cluster sampling method out of the mentioned women. Data collection instruments were a demographic information checklist, Narenji’s Spiritual Health Questionnaire, W aziri and Lotfi Kashani’s Sexual Self - efficacy and Enrich’s Marital Satisfaction questionnaire. The collected data were analyzed using descriptive (mean and standard deviation) and inferential (t - tests, regression and Pearson correlation) statistics. In th is study, all ethical considerations were observed and the authors did not report any conflict of interests .

The results showed that the mean sc ore related to spiritual health of pregnant women was 310/0±4/33. The mean score for sexual self - effic acy in pregnant women was 458/0±4/26. Analysis of variance results showed a significant relationship between spiritual health and its dimensions with sexual self - efficacy (r=0.72) (P<0.05). Spiritual health could also predict sexual self - efficacy in pregna nt women. The results of regression showed that spiritual health in pregnancy could explain 51% of the variance in sexual self - efficacy in pregnant women .

The results of this study showed that sexual self - efficacy and spiritual health of the sa mple population were in good conditions. Spiritual health also had a positive effect on sexual self - efficacy

Numerical models are cost-effective solutions compared to field and laboratory tests that have the ability to predict the behavior of materials with acceptable accuracy if the exact properties of the material are taken into account. Another advantage of numerical models on the meso-scale is the ability to provide the interaction behavior of different components of inhomogeneous materials such as concrete, which is highly effective in predicting the behavior of concrete against dynamic loads. In order to model concrete at the meso-scale, a platform was created to create concrete samples considering aggregates, mortars, and fibers. The platform created in this research can produce elliptical aggregates according to the desired granulation curve in a completely random manner. By controlling the non-interference of aggregates next to each other stochastically placed within the mold boundaries and after determining the sample geometry and grid, The constructed model is converted into input text of numerical analysis programs. Compression and tensile loading are performed on it. Using numerical models, the effect of changes in these parameters was investigated: the volume ratio of aggregates in the sample, the allowable elongation of elliptical aggregates, whether or not to consider the ITZ element, and the use of fibers. In the performed analyzes, the maximum compressive strength and ductility of concrete and, in some cases, the crack propagation path have been investigated. Results show that considering both the maximum strength and the area under the stress-strain diagram; it can be concluded that among the percentages of aggregate volume ratios to the sample equal to 65, 70, 75, and 80%, the volume ratio of 75% to the optimal ratio to achieve the best compressive performance Concrete is closer. Comparison of the shape of the elliptical aggregates in the modeling showed that the closer the aggregate form is to the sphere, the maximum resistance increases, but the strength of the concrete decreases with a steeper slope after the peak.although the analysis of concrete samples at the meso-scale requires much higher computational costs than the macro analysis, this analysis can provide diagrams of tensile and compressive strength of concrete more accurately and also to test new samples with changes in the main parameters acceptable estimation of behavior. Provide concrete without the need to build a physical sample. Studies have shown that unstructured tetrahedron meshing provides graphs closer to empirical results. In analyses with unstructured mesh, mesh size has minimal effect on the results; In the case of models with a structured cubic mesh, the mesh size severely overshadows the analysis results. Suppose the appropriate size for uniform meshing is calibrated using the results of non-structured mesh samples. In that case, results close to the meshes of non-structured samples can be obtained with much less computational time and cost. Although considering the ITZ helps the stress-strain curve at the front of the peak to be closer to the laboratory graphs and also to predict the location of the crack more accurately than without modeling without ITZ, it causes a decrease in resistance at the rear of the peak and is predicted. This can be partially controlled by calibrating the ITZ resistance reduction value.