Samira Heidari

Bio: Samira Heidari is an academic researcher from University of Tehran. The author has contributed to research in topics: Religious education & Philosophy of education. The author has an hindex of 2, co-authored 3 publications receiving 13 citations.

In situ stress measurements of two hydropower projects in Iran by hydraulic fracturing method

Abstract: Hydraulic fracturing is one of the best-known methods of in situ stress measurement at great depths. In the last two decades, this method has been used as an important tool for pre-excavation designing of large projects, e.g., hydroelectric power plants, tunnels, mines, waste disposal galleries, etc. In this paper, some methods of stress calculation in fractured and intact rocks by means of hydraulic fracturing test are described, and the in situ stress states of Aras hydropower project and Roudbar Lorestan pumped-storage project are determined afterwards. The hydraulic fracturing (HF) and hydraulic tests on preexisting fractures (HTPF) tests were carried out in four vertical boreholes at shallow depth (100–190 m) at Aras and two vertical boreholes at almost great depth (440–520 m) at Roudbar Lorestan. The in situ stress magnitudes and orientations are calculated by classical and inversion methods in HF method (great depths) and by differential evolution and Gauss–Newton algorithms in HTPF method (shallow depths). The results of stress measurements illustrate that differential evolution provides better solutions than Gauss–Newton method. It is also demonstrated that the maximum horizontal stress orientation falls in southeast quarter which is in good agreement with the reports published from focal mechanism analysis and the direction of existing faults in Aras Project but deviates from world stress map data in the Rudbar site where it is influenced by the local joints and fractures in the test zone. Eventually, it should be mentioned that the ratio of horizontal to vertical stresses is significantly affected by topography and geology of the test areas. However, this ratio decreases as the depth increases.

A Theoretical Model for Vocational Education Curriculum Based on the Philosophy of Education of the Islamic Republic of Iran

Abstract: هديكچ ىا هفرح شزوـمآ ىـسرد همانرب رد ىرظن ىيوگلا ةـئارا شهوژپ نيا ماـجنا زا فدـه عون زا ىفيك شهوژپ شور .تـسا ناريا ىملاسا ىروهمج تيبرت و ميلعت هفسلف ساـسارب نتفرگ رارق زا انكنارف ىجاتنتسا ىوگلا ساسارب هك انعم نيدب ؛تسا ىجاتنتسا – ىليلحت ىرادرب شيف اه هداد ىروآ عمج رازبا .تسا هدش جارختسا ىلوصا مه رانك رد ىنابم و فادها هيلك و ناريا رد ىملاسا ىروهمج تيبرت و ميلعت هفسلف شهوژپ نيا ىليلحت هعماج .تسا دنمفده روط هب هعماج نـيا زا ىريگ هنومن ،تـسا ىا هفرح شزومآ هنيمز رد دوجوم عـبانم اه هداد ليلحت شور .تـسا هتفرگ تروص ىا هفرح شزومآ ىـسرد همانرب رصانع ساـسارب ماجنا اه هداد ىروآ عمج اب نامزمه و رمتسم روط هب هك هدوب ريسفت و ىراذگدك ،ىدنب هتسد ،ىكاپ :زا دنترابع يا هفرح شزومآ فادها هك تسا نيا زا ىكاح هلصاح ىاه هتفاي .تسا هدش ةيحور ىاقترا و اه هفرح هب تبـسن شنيب و تراهم بسك شِناد ،ىنامـسج توق ،تملاـس يوگلا زا جرختـسم لوصا يخرب نيا رب هولاع .ىا هفرح شزوـمآ نيح رد ىريذپ تكراـشم ،هفرح و راك رد ىنميا لوصا دروم رد مهف و كرد ىاقترا زا دنترابع «اوتحم» شخب رد يرظن اب ملع تقباطم زا ىكاح ليلاد و دهاوـش ندرك مأوت ،هعلاطم دروم عوضوم اب اوتحم طاـبترا طابترا ،اه هفرح ىعامتجا و ىخيرات داعبا رد شواك ،اه هفرح يا هنيمز مولع باب رد عقاو ملاع هرخلااب و تراهم ،شناد ىاه هبنج ندرك ظاحل ،نادرگاـش ةدنيآ ىا هفرح ىاهزاين اب اوتحم ياه هنيمز داجيا :زا دنترابع لوصا نيا زين «ىريگداي» شخب رد .هفرح و راك هب تبسن شنيب رد .نلااـسمه هب كمك رد لضف ندوب اراد و رگيدكي اب ناگدنريگداي لماعت ،يرورـپ هيضرف هب تبـسن شنيب رد لوحت و هنارهام لمع شياديپ :زا دنترابع لوصا نيا «ىهدداي» شـخب شزومآ نيح رد بسانم ىاه هنيمز داجيا ،هفرح و راك ةنيمز رد ىملاسا نيماضم ركذت ،هفرح **تسرپ عون ىرقاب ورسخ رتكد * ىرديح اريمس رتكد ىرظن ىيوگلا هئارا ىا هفرح شزومآ ىسرد همانرب رد ساسارب ناريا ىملاسا ىروهمج تيبرت و ميلعت هفسلف 75 98

Explaining the Views of Ibn Sina and Al-Ghazali on Games and Physical Exercises and their Relation to the Relationship Between Body and Soul

Abstract: The purpose of this article is to describe Ibn Sina and Ghazali's philosophical views on soul and body on the one hand and to express their views on physical movements on the other hand in order to explain the relationship between their philosophical views on games and physical exercises related to body and soul. The research method was descriptive-analytical. The research findings showed that despite the differences in the philosophical thought of Ibn Sina and Ghazali, in the field of proofs of the soul and the body, there is a similarity between these two thinkers and the relationship between the soul and the body is two-ways. With physical activity in the game, there is an effect on the soul and vice versa. In fact, whenever playing and exercising are done in proportion and the body is active, then the soul will also have fun, and this is based on the effect that the body has on the soul. According to the theory of two thinkers, such a conclusion is that games and physical exercises recreate energy and rejuvenates the body and soul.

Characteristic of In Situ Stress and Its Control on the Coalbed Methane Reservoir Permeability in the Eastern Margin of the Ordos Basin, China

Abstract: Coalbed methane (CBM) development faces many challenges, among which in situ stress and permeability are two of the most important and fundamental factors. Knowledge of the characteristics of these factors is crucial to CBM exploration and development. Based on measured injection/falloff and in situ stress well test data of 55 CBM wells in the eastern margin of the Ordos Basin, correlations between parameters including initial reservoir pressure, in situ stress, lateral stress coefficient, well test permeability, and burial depth were determined. The distribution of in situ stress was analyzed systematically and its influence on permeability was also addressed. The results indicate that the maximum horizontal principal stress (σ H 10.13–37.84 MPa, average 22.50 MPa), minimum horizontal principal stress (σ h 6.98–26.88 MPa, average 15.04 MPa) and vertical stress (σ v 12.30–35.72 MPa, average 22.48 MPa) all have positive correlations with coal burial depth. Stress ratios (σ H/σ h, σ H/σ v, and σ h/σ v) and lateral stress coefficient slowly attenuated with depth. With increase of horizontal principal stresses, coal reservoir permeability (0.01–3.33 mD, average 0.65 mD) decreases. The permeability variation is basically consistent with change of stress state at a certain burial depth, the essence of which is the deformation and destruction of coal pore structures under the action of stresses. Three types of stress fields exist in the area: in the shallow coal seam at burial depths <700 m, the horizontal principal stress is dominant, revealing a strike slip regime (σ H > σ v > σ h), with average permeability 0.89 mD; from 700 to 1000 m depths, there is a stress transition zone (σ H ≈ σ v > σ h) with average permeability 0.73 mD; in the deep coal seam with burial depths >1000 m, the vertical principal stress is dominant, demonstrating a normal stress regime (σ v > σ H > σ h) with average permeability 0.11 mD.

Analysis of the distribution characteristics and laws of in situ stress in China’s coal mines

Abstract: Based on the measured in situ stress data in China’s coal mines, the relationship among the type of stress field, magnitude of stress, stress value, and the depth of burial was analyzed. The trends in the changes in side pressure coefficient and side pressure ratio were regressed and fitted with the increase in depth. This was compared to the Hoek-Brown curve, and the distribution characteristics and variation laws of underground stress field in China’s coal mines were determined. (1) Generally, in situ stress increases with burial depth, but the geological structure and lithology render horizontal stress considerable. (2) In 87.72% of stress fields, which are considered typical tectonic stress fields, the horizontal stress comes into prominence. (3) About 64% working environment is the middle- and high-stress zones, and low- and ultrahigh-stress zones account for about 18% each. (4) The ratio of horizontal principal stress was distributed within a range of 1.0~2.5, and it was affected very little by burial depth. However, the difference increased continuously with burial depth, causing an obviously growing shear failure of coal and rock. (5) The side pressure coefficient is mostly distributed in 0.9~2.0, and it decreases with burial depth and is gradually close to 1.32. (6) Most side pressure ratio is in 0.5~1.6. When the burial depth is less than 700~750 m, the horizontal principal stress is lower than one in the world. Conversely, the magnitude of horizontal principal stress was more pronounced in deeper areas, but it always plays a leading role in the in situ stress field. (7) The seismic belt has a great influence on coalfield stress fields. Without affecting the stress field, the direction of maximum principal stress is approximately parallel or perpendicular to the trajectories of principal stress in China Continental Plate. However, under the composite effect of geological structure, the direction changed visibly. There is no apparent relationship between the two and no law to follow. The statistics of in situ stress are important reference values for understanding stress distribution in China’s coal mines, and it also has a practical guiding significance for safely and efficiently mining underground.

Impact of In Situ Stress Distribution Characteristics on Jointed Surrounding Rock Mass Stability of an Underground Cavern near a Hillslope Surface

Abstract: In this paper, a series of numerical simulations are performed to analyze the in situ stress distribution characteristics of the rock mass near different slope angles hillslope surfaces, which are subjected to the vertical gravity stress and different horizontal lateral stresses and the influence which the in situ stress distribution characteristics of 45° hillslope to the integral stability of surrounding rock mass when an underground cavern is excavated considering three different horizontal distances from the underground cavern to the slope surface. It can be concluded from the numerical results that different slope angles and horizontal lateral stresses have a strong impact on the in situ stress distribution and the integral surrounding rock mass stability of the underground cavern when the horizontal distance from the underground cavern to the slope surface is approximately 100 m to 200 m. The relevant results would provide some important constructive suggestions to the engineering site selection and optimization of large-scale underground caverns in hydropower stations.

Fracturing curve and its corresponding gas productivity of coalbed methane wells in the Zhengzhuang block, southern Qinshui Basin, North China:

Abstract: Hydraulic fracturing has been widely used in low permeability coalbed methane reservoirs to enhance gas production. To better evaluate the hydraulic fracturing curve and its effect on gas productiv...