محمود هاشمی

In this study, the effect of the unreinforced and geogrid-reinforced granular blankets, end-bearing stone columns and the combination of these techniques on the behaviour of loose sand soil models have been investigated through laboratory and numerical simulations. In the models, a stone column from a large group of them with a triangular pattern was simulated in a unit cell. Since the rupture of the geosynthetic reinforcement within the reinforced granular blanket has never been experimentally investigated, a novel method of installing the geogrid reinforcement was used, allowing it to mobilize and ultimately fail under loading. The optimal thickness of the unreinforced and geogrid-reinforced blanket, the optimum layout of the reinforcement within the blanket and the changes in the stress concentration ratio of the stone column in different modelling conditions have been determined. Another objective of the present study is to discover the relationship between the failure of the geogrid layers and the characteristics of load-carrying capacity and settlement of the model tests.

Oil and natural energies are important tools in global economic financial policies and the process based on income generation and progress based on it. In this context, oil and oil derivatives play a fundamental role in the economic infrastructure of countries that produce this precious substance. Iran's economy has been mainly based on oil since many years ago, especially from the 1350s onwards. In Iran, first of all, as an energy source, oil has evolved the life and economy of the country's people and caused economic growth and development, secondly, the income from oil has led to advancement and progress in all economic and social pillars. In other words, oil has been the factor of national prestige and the driving engine of economic, social and cultural growth and development of the country. 

The issue of changes in the business model and adaptation to the current market conditions is a fundamental and vital issue, and blockchain is an up-to-date structure in various businesses; It is in different sizes and in different patterns. Blockchain is a data distribution of database based on the community of millions of sharing points, in which data is recorded and modified simultaneously, which can be used by using this open, free and at the same time complex platform. Dealing with financial, scientific and information exchanges. blockchain technology can be considered a network that has a function like a database, but is not centralized and is not controlled by an institution or organization. The information stored in the blockchain has some differences with the information stored in the database. Information in the blockchain is stored in blocks. This information can be anything and is not limited to transactions. Each block has a "hash" in addition to the information stored in it. Hash is a set of characters that special algorithms are used to create. 

In the petroleum industry, blockchains are shared or distributed data structures that can securely store digital transactions without using a central point. Most importantly, blockchain enables the automatic execution of smart contracts in peer-to-peer (P2P) networks. They can be thought of as databases that allow multiple users to make changes to the ledger simultaneously, which can lead to multiple versions of the chain. Instead of the ledger being managed by a trusted center, each individual network member has a copy of the chain of records and agrees on the valid state of the ledger. The precise method of achieving consensus is an ongoing area of research and may vary across a wide range of application domains. New transactions are cryptographically linked to previous transactions, which makes blockchain networks flexible and secure. Each network user can self-check whether transactions are valid, which provides transparency and reliable, tamper-proof records. 

The purpose of this research is to identify the international trade structures of oil derivatives using blockchain technology. In this regard, first by reviewing the verbal evidence of the research and identifying the concepts, we proceed to the open coding process, then the components of the axial coding paradigm including causal conditions, main phenomenon, strategies, background, intervening conditions and consequences are separated and based on categories. Subsets are proposed and finally linked according to selective coding.First, in open coding, the data are broken into separate parts, carefully examined to obtain similarities and differences, and questions about the phenomena that the data indicate. , are raised. Open coding is a part of the analysis that clearly deals with the naming (conceptualization) and categorization of the phenomena through careful examination of the data. Therefore, it can be said that there are two main steps in open coding, which are: conceptualization and categorization.

The investigation showed that the causal conditions include the complexity of the industry - ambiguity and uncertainty in situations, rapid technological developments - integration of technologically oriented companies with companies in this industry - changing competition conditions – necessi,ty and strategic importance.The central phenomenon includes the use of blockchain technology in international trade (petroleum derivatives), market monitoring, competitors monitoring, industry monitoring, company monitoring, document and law monitoring, creating an intelligent information system, industry interactions and exchanges, insurance matters and work contracts.Background conditions include national conditions (growth of social awareness in the oil and gas industry, domestic capacity and capabilities of the country), international conditions (imitating similar successful fields, forming a consortium to join technologies similar), organizational conditions (structural dimensions - globalization culture, technological culture, awareness). Intervention conditions include internal organizational conditions (structural factors - managerial factors - individual factors) and external conditions (economic conditions - political conditions).

Remote sensing data play an important role in environmental planning and monitoring. The current study aimed to investigate the land surface temperature (LST) and the effect of environmental factors on the LST, to identify the temporal-spatial patterns and determine the hot spots in the period of 2013 to 2019, using Landsat 8 images. The effect of spectral indices: Normalized Difference Build-up Index (NDBI), Normalized Difference Vegetation Index (NDVI) and Normalized Difference Water Index (NDWI) on the surface temperature was investigated. Results indicated that the lowest average temperature has occurred in 2019 and the highest LST was in the 2017. The results of Moran's index correlation also showed that the most clustering pattern of LST, with the Moran value of 0.85 was obtained in 2019, the highest correlation between LST and NDBI, with the R value of 0.76 in the 2015, the highest correlation between LST and NDVI in the 2015 (R = -0.56), and the highest correlation between LST and NDWI in 2013 (R = -0.53). Rasht watershed in Guilan province is affected by human factors and land use changes. Therefore, it is recommended to increase the vegetation cover in urban areas, reduce the change of pasture to agricultural area, and reduce forest destruction.

Monopile is the most common type of foundation for onshore and offshore wind turbines. Wind load alternately applies in different directions during the life cycle of the wind turbine. In this paper, the influence of alternating change of wind load direction on the response of wind turbine piles is studied. The functional performance of soil-pile system is simulated with a bounding surface soil behavior model presented by Dafaliad-Manzari that is implemented in FLAC3D software. The softening and hardening effects of soils due to cyclic load patterns is incorporated in the model in a convenient manner. The results show that alternative change in the direction of loading results in the decrease in the maximum horizontal displacement and rotation up to 16% in comparison with the uni-directional loading mode. This difference in vertical displacement is about 100%. Residual displacement and rotation in the horizontal direction also decreases 13% and 18%, respectively. Alternating change of loading causes upward moves of the monopile; the pile moves upward from its original level. In general, the change of loading direction causes a significant change in the pile response, although the values of this difference vary in different parameters and for altered loading modes.

The ability to think strategically at multiple organizational levels is critical to leaders and managers. Specific work experiences can contribute to the development of an individual's strategic thinking ability. Therefore, the capacity of managers for strategic thinking is the key to a high level of performance.The purpose of this study was to design an effective model for the development of strategic thinking of human resource managers of the National Iranian Gas Company in terms of productivity and individual innovation. The present study was applied in terms of purpose, in terms of nature, survey and part of combined-exploratory research. The results indicate that senior management, individual factors, group factors, organizational factors and systemic factors affect the strategic thinking of the organization. Also, the analysis of statistical data proved that the use of strategic thinking on productivity in the implementation of organizational policies has a positive and significant relationship. The ISM technique was also used to conduct this research. Finally, after conducting research, the systemic approach is at the first level, which means that this index is the most influential element. At the last level is the senior management index, which means that this index is the most influential factor among the factors affecting the strategic thinking of human resources.

The purpose of this research is to study the feasibility and method of using xanthan biopolymer as an alternative for oil mulch in controlling or mitigating soil wind erosion. Xanthan is a biodegradable biopolymer made of Polysaccharides which is produced by bacteria and is used as stabilizer. The ability of different concentrations of xanthan in reducing the erosion, was examined by wind tunnel tests at speed of 7 to 15 m/s. To do so, xanthan gum suspension was sprayed on the surface of sand samples collected from sandy hills of Segzi plain in Isfahan and samples resistance to wind erosion were tested by wind tunnel after being dried. The test results indicated that a resistant crust is formed on sample surface due to spraying xanthan biopolymer, so that 2 gr/m2 of this biopolymer can reduce erosion up to 98 percent compared to untreated sample. Application of xanthan doesn’t need any advanced equipment and it can be sprayed cold. Cost of mulching with oil mulch in March 2020 to March 2021 was estimated to be 13 times more than mulching with xanthan gum. According to environmental standards, this biopolymer is also safe for using on soil resources.

The present study investigated the effect of guar biopolymer on soil wind erosion. Assuming that Guar gum can control wind erosion, its ability to reduce soil wind erosion was examined by wind tunnel tests. Examined soil samples were gathered from sandy hills of Segzi plain, located in Isfahan Province. Then were prepared in plates with diameter of 23 cm treated with guar gum suspension so that 0.2, 0.4, 0.8, 1 and 1.2 gr of the biopolymer were scattered per square meter of sample surface. Wind tunnel tests were performed on samples at speed of 7 m/s to 15 m/s. The test results indicated that the resistant crust formed on soil surface due to spraying Guar suspension can highly increase soil resistance to wind erosion. 1.2 gr/m2 of Guar can reduce erosion up to 98 percent. Soil sieving analysis results pointed out that Guar gum causes enlargement of the soil aggregates and so in reduction of erosion and raise in threshold wind velocity from 7 to 10 m/s. Thus, using Guar gum can be considered as a suitable method for controlling soil wind erosion, after the field experiments.

A wide variety of systems have been introduced so far for the construction of roofs, as one of the most essential structural components of buildings. A conventional roofing system is the solid slab that offers adequate rigidity to distribute gravitational and seismic loads, while it is also relatively resistant against fire. However, its main drawback is its overweight that increases the associated seismic loads. To resolve this problem, modifications were proposed that resulted in different types of biaxial voided slabs. In one such system, spherical and ellipsoidal plastic balls enclosed in steel cages were used to eliminate ineffective concrete. Due to the novelty of the system, however, little was known about the bending behavior of the roof thus constructed. Most of previous studies have been conducted on spherically-shaped voids ignoring ellipsoidal ones. This is while the effect of supporting cages on voids has not been investigated at all. The present study was, therefore, designed and implemented to study the behavior of biaxial voided slabs containing ellipsoidal plastic balls and the effect of supporting cages on bending behavior. To investigate these aspects of the system, two full-scale bending specimens were cast for investigating bending capacity, cracking distribution, and deflection in solid and biaxial voided slabs. Moreover, the effect of cage longitudinal rods was studied on the ultimate capacity of the bending specimens. Finally, the experimental results were then examined by ACI 318-14 recommendations to put forth suggestions for using the ACI 318-14 equations in designing biaxial voided slabs. It was found that while both solid and biaxial voided specimens exhibited almost similar bending behavior and the same failure mode. Also, the bending behavior of biaxial voided specimen was affected by the steel cages used. So, to use the ACI 318-14 equations, if this longitudinal cage bar is considered, the percentage difference between experimental and calculated results reached just one percent.

Determining the mechanical and dynamic parameters of the rocks under different environmental conditions of laboratory, device, and rock samples tested. Triaxial test is one of the most useful tests for mechanical behavior of rocks, which be done by advanced servo-controlled devices, can determined important parameters such as mechanical strength, modulus of deformeabilities and variations in the velocity of the wave during loading continuously. In this paper, at first some of the physical and geological characteristics of two types of clastic rocks (sandstone and tuff) evaluated, and then their mechanical and dynamic parameters determined during servo-controlled triaxial test in different conditions of lateral and axial stress studied. The values of parameters such as modulus of deformeability, the poisson's ratio, and longitudinal and transverse wave velocities, which are usually stated constant, change with increasing axial and lateral stresses during the test, because the sample's behavior changes from elastic to plastic during test. Therefore, providing fixed value for a parameter can't be logical and must specify the conditions for its determination along with the declared number. The results of triaxial test of this study, carried out by the ISRM standard method, show that the resistance values, the modulus of deformeability, the poisson's ratio and the wave velocity of the longitudinal and transverse waves for the sandstone sample are higher than that of the pyroclastic sample, due to the difference in physical properties and the structure and texture of these two rocks. The range of variations of these parameters is different in two specimens.

Lifestyle is almost a harmony of all behaviors and actions that a person shows during everyday life, in fact, is a lifestyle of daily orientations and meanings, life style with the formation of people's culture of relationship So it is possible to obtain the necessary knowledge about the culture of a society through the recognition of the lifestyle of that society. Considering the trend of globalization and communication cyberries that lead people to the consumer culture, in this study, we seek to study the lifestyle and culture of consumption among the youth of Dashtestan and how their family's socio-economic status is affected by this process.

The present study studied the effect of family socio-economic status on the youth lifestyle using a survey method. The population of this study included 48912 youths aged 15-29 in Dashtestan, with a sample size of 380 and using the formula Cochran has been obtained. Sampling was done using multistage cluster sampling. Cronbach's method was used to assess the reliability of the items. To assess the validity of the items, the method of credit assessment of the Lavasheh content was used and the obtained data were analyzed by SPSS software and the results were presented in descriptive and inferential statistics.

The results of the study showed that there is no significant difference between the lifestyle of young and old boys and the fifth hypothesis; it seems that there is no difference between the lifestyle of the young and the boy children. In just a few questions, the average of the young and the younger boy's ratings differed. For example, young girls are much less likely to play sports than young boys, and different types of girls and boys' sports. In the case of the question that the husband and wife should live with the bridegroom after the marriage, the girl's youth showed more disagreement than the boys. Girls also had less interest in going to fast food.

In this article, Umbrella drainage system is presented as a alternative drainage system for the tunnels under steady state-seepage condition. The arrangement of this system is inspired from pin-hole drainage system and forepoling method of support installation. In this study, the performance of this drainage system is investigated through numerical statical analysis for deep circular tunnels subjected to steady-state seepage by using ABAQUS finite element software. In this regard, three monitoring parameters have been investigated: tunnel domain’s maximum effective principle strain, pore water pressure distribution of the tunnel walls and hydraulic gradient around the drainages. By taking into account these parameters, an optimum arrangement for the draining system is presented through exploring all of the factors affecting the drainage tube performance.

One of the major issues in design and construction of tunnels is seepage and it's been highlighted by an extra force which is generated by pore water pressure and directed towards the tunnel walls. Since this extra seepage force may lead to instability in soils and weak rocks with low permeability, the necessity of drainage in such tunnels is visibly clear. Drainage systems in tunnels have dierent types and materials and the most common ones are peripheral lter drainage and pin-hole drainage systems. Despite the drainage system importance, very limited studies have been conducted on the drainage systems and the eective factors aecting their performance. The need for such systems is clearly felt during construction of many tunnels during the writers eld studies.
In this article, Umbrella drainage system is presented as a new alternative drainage system for the tunnels under steady state seepage condition. The arrangement of this system is an smart combination of Pin-Hole drainage system and it is inspired by forepoling method of support installation. In this study, the performance of the aforementioned drainage system is investigated through numerical statical three dimensional analysis of the lining for deep circular tunnels subjected to steady-state seepage by using ABAQUS nite element software. Furthermore an optimum arrangement for pipes in the drainage system is presented by taking into account the maximum eective principle strain for the lining of a tunnel as a monitored parameter. Also the eective factors affecting the drainage tube of the draining system is to investigated. Moreover, all of the factors with an in- uence on the drainage tube of this draining system is explored through investigating the pore water pressure distribution on the surface of the lining of a tunnel and considering it as a type of eective loading in designing the lining of the tunnel and also estimating the drained volumetric discharge of the drainage tubes.

At present، there are still large numbers of existing buildings in Iran that are made of adobe. Isfahan is a historical city in Central Iran which enjoys the abundance of its historical and non-historical adobe buildings، some of which belong toseveral centuries ago. There are also many small villages inside and around Isfahan region that are totally made of adobe and accomodate tens of thousands of inhabitants. Recently، many researches have focused on improving the structural behaviour of adobe buildings، which includes enhancing mechanical properties of adobe units، and retrofitting and strengthening methods of existing adobe structures. In order to improve the mechanical properties of adobe made of soils in Isfahan region، used for restoration or reconstruction of the buildings، the effect of additives including sand، gypsum، lime، brick powder and straw with different amounts and were studied by planning 21 mix design schemes. After adding additives and making mix designs، the relevant mechanical tests were conducted. The obtained mechanical properties for every mix design were then compared with simple adobe (without additives). Soil used for making adobe is obtained from Habibabad region، North-east of Isfahan. The laboratory tests have been devided in two groups; The first group was considered the primary phase of the project، which consisted of the tests on plain soil including water content، grading، sedimentation، plastic limit، liquid limit and methylene blue tests. The second group or the second phase of the project was conducted on adobe samples and was comprised of compressive strength، flexural strength، abrasive strength and capillary absorption tests. The laboratory tests and relations used in this study have been applied according to the procedures suggested by Centre for the Development of Enterprise (CDE). Formulating the mix designs and laboratory tests on the designed samples were performed in the the soil and construction materials laboratory of the University of Isfahan during eight months. Obtained results indicate that gypsum or the combination of brick powder and gypsum are the best additives for adobe made from North-east Isfahan soil due to the resulting improvements in mechanical characteristics. The most appropriate mix ratios to be added to the plain soil are 25% gypsum of total weight or combination of 10% birck powder and 20% gypsum to be added to the soil. Lime as an additive has always played a negative role and reduces mechanical strengths of adobe، and therefore it is not recommended.

In this paper, the effect of steel fibres on the mechanical properties and thermal and freezing performance of lightweight self-compacting concrete consisting of Leca and microsilica gel has been studied. For this reason, the effect of three different contents of steel fibres on rheological and mechanical properties, including compressive, tensile and flexural strengths, and on concrete performance against thermal loading and freezing has been investigated. At the first stage, ten mix designs have been made by changing the amount of water, microsilica gel, stone powder and Leca contents. Then, slump, J-ring, U-box, L-box and V-funnel tests have been done. After selecting the control mix, 7-, 28- and 90-day compressive and tensile strengths tests, 90-day flexural and thermal tests, and 28-day freezing and thawing test have been performed. Obtained results indicate that steel fibres have increased tensile and compressive strengths by 95% and 16%, respectively. They have improved thermal durability at high temperatures and have prevented the loss of compressive and tensile strengths by 13% and 92%, respectively. The existence of steel fibres has enhanced the behaviour of concrete in freezing and thawing cycles by decreasing the loss of compressive and flexural strengths by 8% and 15%, respectively.

In recent years, because of population growth and water shortages due to global warming, groundwater use in agriculture, industry and households has been growing. This is one of the main causes of subsidence occurred in Iran. To study this phenomenon, some approaches such as GPS and geodetic leveling can be used. But the study of this phenomenon becomes easier by using InSAR technique. Using this technique, the displacement in the region field without the need for large working, with high precision, and with less expenditure can be observed. In this report, in temporal and spatial changes subsidence in Mahyar of Isfahan is studied. About 30 years ago in the plains and rift-related subsidence has been observed that the deformation of serious damage to agricultural land, roads and constructional. .. is followed. For that, 15 images of InSAR of ENVISAT within the period 2006-2003 with short base (SBAS) method were used. This method is provided subsidence map. Base on result, there is an 8.6 cm of subsidence in Mahyar.