This study focuses on the geochemistry of trace elements and parameters of coal quality of bituminous coal belonging to the upper Triassic-lower Jurassic era, collected from the Galandrud region in Central Alborz, nor...This study focuses on the geochemistry of trace elements and parameters of coal quality of bituminous coal belonging to the upper Triassic-lower Jurassic era, collected from the Galandrud region in Central Alborz, northern Iran. Galandrud coal on an air-dried basis are characterized by broad variation in the amount of ash （ranging from 6.49g to 12.73%）, a high content of volatile matter （33,32-37.45%） and high gross calorific values （7430-8880 kcal/kg）. The mineral matter of the coal samples studied is made up of dolomite （〉909g）, quartz, sphalerite, galena, pyrite and clay minerals. Major elements are positively cor- related with ash content suggesting an association with inorganic constituents. Based on statistical anal- yses, concentrations of trace elements such as Co （51.3 ×10^-6-152.9× 10^-6）, Ba （368× 10^-6-3297.4×10^-6）, Cr （65.5 ×10^-6-194.2 × 10^-6）, Mo （5.6 × 10^-6-18.2× 10^-6）, Hi （72.9 × 10^-6-152.9 × 10^-6） and V （245.5 × 10^-6-520 ×10^-6） are higher than world coal averages. However, low concentration of some vol- atile elements such as As, Hg and U are present in low concentrations of the various types of coal studied.展开更多
A case study was conducted in beech forests of northern Iran to determine the effect of the created gaps on some soil properties in beech stand. Changes of soil properties in small （60-150 mE）, medium （151-241 mE）...A case study was conducted in beech forests of northern Iran to determine the effect of the created gaps on some soil properties in beech stand. Changes of soil properties in small （60-150 mE）, medium （151-241 mE）, large （242-332 m^2） and very large （333-550 m^2） gaps, as well as under closed stands were studied eight years after-the gap creation. Soil samples were taken from three depths, 0-10, 10-20 and 20-30 cm. The gaps were different from their around undisturbed stands in terms of the following soil parameters： Mg^＋2 concentration of 0-10 cm at medium gap size, bulk density of 10-20 cm at very large gap size as well as K^＋ and Ca^＋2 concentrations at 20-30 cm at small and large gap sizes, respectively. Furthermore, the size of the gaps had no effect on soil characteristics through the whole profile. Water saturation percent （Sp %） at 0-10cm as well as P and Mg^＋2 at 20--30 cm was different amongst undisturbed stands around different gap sizes. The center and the edges of the gap were different only in terms of organic carbon at the depth of 10-20 cm. Significant differences were observed between gaps and closed canopy regarding P and Ca^＋2 at depth 0--10 cm and 10-20 cm, respectively. It can be concluded that applied silvicultural system for harvesting trees which created these gaps might be suitable for conservation and forest management in the region.展开更多
Nowadays, there are a lot of challenges for global processing in countries economic companies. One of the important reasons is lack of changes that must be with world-class technology for making a competition in indus...Nowadays, there are a lot of challenges for global processing in countries economic companies. One of the important reasons is lack of changes that must be with world-class technology for making a competition in industry, and another important reason is lack of organized distinction for managers. Most of high rank managers don＇t have good points for charging and worry about it. In this essay, there have been excellence organized model of EFQM and Iran national quality award which are compared by a case study, and finally, it has suggested using a native model.展开更多
Drilling crews of Sinopec have encountered a series of troubles when drilling a formation called kazhdumi of Yadavaran oilfield, Iran in the last few years. The formation is buried in the depth from 3300m to 3500m, ma...Drilling crews of Sinopec have encountered a series of troubles when drilling a formation called kazhdumi of Yadavaran oilfield, Iran in the last few years. The formation is buried in the depth from 3300m to 3500m, mainly including limestone, muddy limestone and some bituminous shale. Many microfissures exist in the formation and the equivalent density of formation pore pressure ranged from 1.19g/cm3 to 1.59g/cm3. Asphalt or heavy oil kicks occurred in drilling three wells in one and a half years, which contaminated the drilling fluid and made well killing difficult due to the kicks and lost circulation in open hole. Gas and hydrogen sulfide （the concentration is up to 40000ppm） were present in the wells, and finally two wells were completely abandoned and one partially losL which frustrated the drilling engineering seriously. By analyzing the data of ＆e drilled wells, the paper summarized the causes of the troubles, and put forward suggestions and conclusions that can serve as reference and guideline for drilling well in ＆is area in the future.展开更多
This study aims at investigating the AIS （Agricultural Information System） in Hamedan province, Iran, benefiting from the list of criteria for well functioning AISs that were identified in earlier researches. For th...This study aims at investigating the AIS （Agricultural Information System） in Hamedan province, Iran, benefiting from the list of criteria for well functioning AISs that were identified in earlier researches. For this purpose, a survey method with multi-stage stratified random sampling technique was used to select 31 agricultural researchers, and 62 extension workers in the province. The data were acquired by questionnaire and structured interviews. The instrument for data collection was subjected to pre-testing, validation and reliability tests. The results of the factor analysis revealed that the criteria could be categorized into four overarching groups based on their inter-correlation. The analysis of mentioned criteria in Hamedan province AIS showed less efficiency and effectiveness than studies conducted in other areas. But among these, two desirable criteria existed. It is recommended that the ecological knowledge system （EKS） should be integrated with AIS, and some ecological and sustainable development criteria should be added to the existing ones.展开更多
The so-called blisks,i.e.integrally bladed disks,are characterized by very low viscous material damping and make the flutter prediction much more critical.In that framework,a two-dimensional numerical study of a space...The so-called blisks,i.e.integrally bladed disks,are characterized by very low viscous material damping and make the flutter prediction much more critical.In that framework,a two-dimensional numerical study of a space turbine blisk featuring complex deformation of blades and high eigenfrequency(>40kHz)is performed.The simulations are based on unsteady Reynolds Averaged Navier Stokes computations linearized in the frequency domain and consist in the superposition of an unsteady linear(in time)pressure field,generated by a harmonic perturbation,upon a steady nonlinear(in space)flow.The aerodynamic damping coefficient is calculated over a range of nodal diameters,and the blades are predicted aeroelastically stable.However,violent changes occur and are rather critical since sudden and large deviations in stability appear.In that context,the nature of the waves propagating from the cascade are evaluated.Such an approach provides fundamental knowledge about the perturbations which can either propagate to the far-field(cut-on mode)or decay(cut-off mode).It is expected that the ability of the flow to damp or to amplify the blade motion is strongly affected by the way unsteady perturbations are transferred from the cascade to the far-field.The nature of the waves are first assessed from the aforementioned linearized results,then they are evaluated analytically and finally compared.A good agreement is found despite the strong assumptions of the analytical model.The results show a clear correlation between the cut-on/cut-off conditions and stability.The least stable configuration corresponds to cut-off mode at the inlet and no wave at the outlet.Without outgoing waves from the cascade,the blade is prone to be less stable:the energy from the blades vibration is necessarily dissipated or sent out by the cascade.展开更多
Objective： To describe mortality pattern and to determine undiagnosed fatal injuries according to autopsy findings among road traffic accident victims in Yazd, Iran. Methods： In this retrospective study, 251 victims...Objective： To describe mortality pattern and to determine undiagnosed fatal injuries according to autopsy findings among road traffic accident victims in Yazd, Iran. Methods： In this retrospective study, 251 victims of road traffic accidents who were admitted to a tertiary trauma hospital over a two-year period （2006 and 2007） and received medical cares were included. Hospital records were reviewed to gather demographic characteristics, road user type, and medical data. Autopsy records were also reviewed to determine actual causes of death and possible undiagnosed injuries occurred in the initial assessment of the emergency unit or during hospitalization. Results： There were 202 males （80.5%） and 49 females （19.5%）. The mean （＋SD） age of fatalities was 34.1 （＋21.5） years. Pedestrian-vehicle accidents were the most common cause of trauma （100 cases, 39.8%）. The most common cause of death was central nervous system injury （146 cases, 58.1%）. The other causes were skull base fractures （10%）, internalbleeding （8%）, lower limb hemorrhage （8%）, skull vault fractures （4%）, cervical spinal cord injury （3.6%）, airway compromise （3.2%）, and multifactor cases （5.1%）, respectively. Thirty-six fatal injuries in 30 victims （12%） mainly contributed to death according to autopsy, but were not diagnosed in initial assessments. The head （72.2%） and cervical spine （13.8%） regions were the two most common sites for undi- agnosed injuries. Conclusion： Training courses for emergency unit medical staff with regard to interpreting radiological findings of head and neck and high clinical suspicion for cervical spine injuries are essential to improve the quality of early hospital care and reduce the mortality and morbidity of traffic accident patients.展开更多
This paper presents the role of tectonic and karstic processes in the formation and evolution of Barm Firuz Lake within the Zagros Mountains of Iran. This lake with elevation of 3 340 m from sea level is located in th...This paper presents the role of tectonic and karstic processes in the formation and evolution of Barm Firuz Lake within the Zagros Mountains of Iran. This lake with elevation of 3 340 m from sea level is located in the crest of the Barm Firuz anticline. Results show that the structural evolution of the Barme Firuz Lake is related to both tectonic and karst processes. Therefore the term of tectonokarstic has been used for structural evolution of the lake. Structural studies especially on the stylolite structures revealed the occurrence of an important component of simple shear deformation in the study area. Based on structural and karstic evidence around the lake, the fault-dissolution sink model with oblique pure shear component is suggested as kinematic model of the Barm Firuz Lake evolution in the Zagros Mountains of Iran.展开更多
Objectives： To review the calendar, mortality and morbidity of Iraq-Iran chemical war among Iranians based on researchers＇ reports. Methods： We used national and international databanks such as PubMed, ISI, Scopus...Objectives： To review the calendar, mortality and morbidity of Iraq-Iran chemical war among Iranians based on researchers＇ reports. Methods： We used national and international databanks such as PubMed, ISI, Scopus, Irandoc and Iranmedex and studied 350 articles related to chemical agents and their effects on different organs. The main criteria for qualification of articles were relevancy orientation and being published in approved medical journals. Results： The Iraqi army invaded to west and southwest Iran using chemical weapons such as nerve agents （NAs） and sulfur mustard （SM）. Most victims were civilians including women and children. These attacks had imposed more than 150 types of diseases and complications on Iranians and the frequency of death was 2%-3%. Most reports were about respiratory problems and a few were in the domain of socio-economic damages Conclusion： At present, 25 years after me end of war, the victims are faced with different complications induced by chemical agents and it is estimated that they will be continuously troubled by these problems in future.展开更多
基金supported by the Iranian Institute for Geological Surveys and Mineral Exploration
文摘This study focuses on the geochemistry of trace elements and parameters of coal quality of bituminous coal belonging to the upper Triassic-lower Jurassic era, collected from the Galandrud region in Central Alborz, northern Iran. Galandrud coal on an air-dried basis are characterized by broad variation in the amount of ash （ranging from 6.49g to 12.73%）, a high content of volatile matter （33,32-37.45%） and high gross calorific values （7430-8880 kcal/kg）. The mineral matter of the coal samples studied is made up of dolomite （〉909g）, quartz, sphalerite, galena, pyrite and clay minerals. Major elements are positively cor- related with ash content suggesting an association with inorganic constituents. Based on statistical anal- yses, concentrations of trace elements such as Co （51.3 ×10^-6-152.9× 10^-6）, Ba （368× 10^-6-3297.4×10^-6）, Cr （65.5 ×10^-6-194.2 × 10^-6）, Mo （5.6 × 10^-6-18.2× 10^-6）, Hi （72.9 × 10^-6-152.9 × 10^-6） and V （245.5 × 10^-6-520 ×10^-6） are higher than world coal averages. However, low concentration of some vol- atile elements such as As, Hg and U are present in low concentrations of the various types of coal studied.
文摘A case study was conducted in beech forests of northern Iran to determine the effect of the created gaps on some soil properties in beech stand. Changes of soil properties in small （60-150 mE）, medium （151-241 mE）, large （242-332 m^2） and very large （333-550 m^2） gaps, as well as under closed stands were studied eight years after-the gap creation. Soil samples were taken from three depths, 0-10, 10-20 and 20-30 cm. The gaps were different from their around undisturbed stands in terms of the following soil parameters： Mg^＋2 concentration of 0-10 cm at medium gap size, bulk density of 10-20 cm at very large gap size as well as K^＋ and Ca^＋2 concentrations at 20-30 cm at small and large gap sizes, respectively. Furthermore, the size of the gaps had no effect on soil characteristics through the whole profile. Water saturation percent （Sp %） at 0-10cm as well as P and Mg^＋2 at 20--30 cm was different amongst undisturbed stands around different gap sizes. The center and the edges of the gap were different only in terms of organic carbon at the depth of 10-20 cm. Significant differences were observed between gaps and closed canopy regarding P and Ca^＋2 at depth 0--10 cm and 10-20 cm, respectively. It can be concluded that applied silvicultural system for harvesting trees which created these gaps might be suitable for conservation and forest management in the region.
文摘Nowadays, there are a lot of challenges for global processing in countries economic companies. One of the important reasons is lack of changes that must be with world-class technology for making a competition in industry, and another important reason is lack of organized distinction for managers. Most of high rank managers don＇t have good points for charging and worry about it. In this essay, there have been excellence organized model of EFQM and Iran national quality award which are compared by a case study, and finally, it has suggested using a native model.
文摘Drilling crews of Sinopec have encountered a series of troubles when drilling a formation called kazhdumi of Yadavaran oilfield, Iran in the last few years. The formation is buried in the depth from 3300m to 3500m, mainly including limestone, muddy limestone and some bituminous shale. Many microfissures exist in the formation and the equivalent density of formation pore pressure ranged from 1.19g/cm3 to 1.59g/cm3. Asphalt or heavy oil kicks occurred in drilling three wells in one and a half years, which contaminated the drilling fluid and made well killing difficult due to the kicks and lost circulation in open hole. Gas and hydrogen sulfide （the concentration is up to 40000ppm） were present in the wells, and finally two wells were completely abandoned and one partially losL which frustrated the drilling engineering seriously. By analyzing the data of ＆e drilled wells, the paper summarized the causes of the troubles, and put forward suggestions and conclusions that can serve as reference and guideline for drilling well in ＆is area in the future.
文摘This study aims at investigating the AIS （Agricultural Information System） in Hamedan province, Iran, benefiting from the list of criteria for well functioning AISs that were identified in earlier researches. For this purpose, a survey method with multi-stage stratified random sampling technique was used to select 31 agricultural researchers, and 62 extension workers in the province. The data were acquired by questionnaire and structured interviews. The instrument for data collection was subjected to pre-testing, validation and reliability tests. The results of the factor analysis revealed that the criteria could be categorized into four overarching groups based on their inter-correlation. The analysis of mentioned criteria in Hamedan province AIS showed less efficiency and effectiveness than studies conducted in other areas. But among these, two desirable criteria existed. It is recommended that the ecological knowledge system （EKS） should be integrated with AIS, and some ecological and sustainable development criteria should be added to the existing ones.
基金the Centre National d'Etudes Spatiales (CNES) and Snecma for their financial supportthe Centre Informatique National de l'Enseignement Supérieur (CINES) for the computational resources,and the Agence Nationale de la Recherche(ANR) for sponsoring the project ANR-08-2009 CapCAO (parametrization-aided optimized aeroelastic design)
文摘The so-called blisks,i.e.integrally bladed disks,are characterized by very low viscous material damping and make the flutter prediction much more critical.In that framework,a two-dimensional numerical study of a space turbine blisk featuring complex deformation of blades and high eigenfrequency(>40kHz)is performed.The simulations are based on unsteady Reynolds Averaged Navier Stokes computations linearized in the frequency domain and consist in the superposition of an unsteady linear(in time)pressure field,generated by a harmonic perturbation,upon a steady nonlinear(in space)flow.The aerodynamic damping coefficient is calculated over a range of nodal diameters,and the blades are predicted aeroelastically stable.However,violent changes occur and are rather critical since sudden and large deviations in stability appear.In that context,the nature of the waves propagating from the cascade are evaluated.Such an approach provides fundamental knowledge about the perturbations which can either propagate to the far-field(cut-on mode)or decay(cut-off mode).It is expected that the ability of the flow to damp or to amplify the blade motion is strongly affected by the way unsteady perturbations are transferred from the cascade to the far-field.The nature of the waves are first assessed from the aforementioned linearized results,then they are evaluated analytically and finally compared.A good agreement is found despite the strong assumptions of the analytical model.The results show a clear correlation between the cut-on/cut-off conditions and stability.The least stable configuration corresponds to cut-off mode at the inlet and no wave at the outlet.Without outgoing waves from the cascade,the blade is prone to be less stable:the energy from the blades vibration is necessarily dissipated or sent out by the cascade.
文摘Objective： To describe mortality pattern and to determine undiagnosed fatal injuries according to autopsy findings among road traffic accident victims in Yazd, Iran. Methods： In this retrospective study, 251 victims of road traffic accidents who were admitted to a tertiary trauma hospital over a two-year period （2006 and 2007） and received medical cares were included. Hospital records were reviewed to gather demographic characteristics, road user type, and medical data. Autopsy records were also reviewed to determine actual causes of death and possible undiagnosed injuries occurred in the initial assessment of the emergency unit or during hospitalization. Results： There were 202 males （80.5%） and 49 females （19.5%）. The mean （＋SD） age of fatalities was 34.1 （＋21.5） years. Pedestrian-vehicle accidents were the most common cause of trauma （100 cases, 39.8%）. The most common cause of death was central nervous system injury （146 cases, 58.1%）. The other causes were skull base fractures （10%）, internalbleeding （8%）, lower limb hemorrhage （8%）, skull vault fractures （4%）, cervical spinal cord injury （3.6%）, airway compromise （3.2%）, and multifactor cases （5.1%）, respectively. Thirty-six fatal injuries in 30 victims （12%） mainly contributed to death according to autopsy, but were not diagnosed in initial assessments. The head （72.2%） and cervical spine （13.8%） regions were the two most common sites for undi- agnosed injuries. Conclusion： Training courses for emergency unit medical staff with regard to interpreting radiological findings of head and neck and high clinical suspicion for cervical spine injuries are essential to improve the quality of early hospital care and reduce the mortality and morbidity of traffic accident patients.
文摘This paper presents the role of tectonic and karstic processes in the formation and evolution of Barm Firuz Lake within the Zagros Mountains of Iran. This lake with elevation of 3 340 m from sea level is located in the crest of the Barm Firuz anticline. Results show that the structural evolution of the Barme Firuz Lake is related to both tectonic and karst processes. Therefore the term of tectonokarstic has been used for structural evolution of the lake. Structural studies especially on the stylolite structures revealed the occurrence of an important component of simple shear deformation in the study area. Based on structural and karstic evidence around the lake, the fault-dissolution sink model with oblique pure shear component is suggested as kinematic model of the Barm Firuz Lake evolution in the Zagros Mountains of Iran.
文摘Objectives： To review the calendar, mortality and morbidity of Iraq-Iran chemical war among Iranians based on researchers＇ reports. Methods： We used national and international databanks such as PubMed, ISI, Scopus, Irandoc and Iranmedex and studied 350 articles related to chemical agents and their effects on different organs. The main criteria for qualification of articles were relevancy orientation and being published in approved medical journals. Results： The Iraqi army invaded to west and southwest Iran using chemical weapons such as nerve agents （NAs） and sulfur mustard （SM）. Most victims were civilians including women and children. These attacks had imposed more than 150 types of diseases and complications on Iranians and the frequency of death was 2%-3%. Most reports were about respiratory problems and a few were in the domain of socio-economic damages Conclusion： At present, 25 years after me end of war, the victims are faced with different complications induced by chemical agents and it is estimated that they will be continuously troubled by these problems in future.
