Characterizing the subsurface structure is an important parameter for the improvement of seismic hazard assessment.Due to the tectonic complexity of the earth,some deep fractures do not reach the earth's surface a...Characterizing the subsurface structure is an important parameter for the improvement of seismic hazard assessment.Due to the tectonic complexity of the earth,some deep fractures do not reach the earth's surface and are not detectable with visual analysis.Therefore,the lack of knowledge of faults and fractures can result in disasters,especially in urban planning.Many geophysical methods can be used to estimate subsurface structure characterization.However,a more reliable method is required to assess seismic hazards and reduce potential damage in metropolitan areas without destroying buildings and structures.This paper aims to identify hidden faults and structures using shear wave velocity sections.To do this,surface wave dispersion curve was extracted from the vertical component of microtremor array recording using the spatial autocorrelation(SPAC)method in two profiles and 13 array stations(perpendicular to the altitudes)to obtain shear wave velocity structure(Vs)in the west of Mashhad,northeast of Iran.The results of shear wave velocity profiles(Vs)indicate sudden changes in the thickness of sediments.This can be related to the displacement of a normal fault in this area causing the bottom rock to fall and an increase in the alluvial thickness in the central part of the plain.The velocity in the floor rock is 2000 meters per second in this area.According to the surface outcrops and water wells data,its material is slate and Phyllite metamorphic rocks that are exposed in the adjacent heights.Besides,the seismic profile results were well consistent with electrical resistance data and well logs indicating that the tool array method is flexible,non-invasive,relatively fast,and effective for urban areas with satisfactory accuracy.展开更多
Residual soils are weathering products of rocks that are commonly found under unsaturated conditions.The properties of residual soils are a function of the degree of weathering.A series of index properties,engineering...Residual soils are weathering products of rocks that are commonly found under unsaturated conditions.The properties of residual soils are a function of the degree of weathering.A series of index properties,engineering properties and geophysics survey examinations were performed on residual soils from two major geological formations in Iran.In the present research,the index properties of residual soils in the south of Mashhad city in Iran are investigated.Natural and artificial trenches were analyzed for evaluating the weathering profiles and collecting soil samples.Disturbed and undisturbed samples were obtained from each of the soil profile horizons resulting from weathering of different parent rocks.Subsequently,physical properties and mechanical properties of the soil samples were determined in accordance with ASTM standards.Also,the mineralogical composition,chemistry,and texture of the soil were evaluated in 51 profiles.The field observations showed the difference in the weathering profile of residual soils deposited on various rocks(igneous,sedimentary,and metamorphic).These profiles mainly consisted of two horizons includingresidual soil on top and saprolite at the bottom.The results of laboratory tests and geotechnical data showed that the properties of residual soil samples change by depth.Moreover,depending on the type of origin rock,the properties are different in various types of residual soils.In most of the samples,the moisture content of soil horizons was also increased by depth.Based on the unified soil classification(USCS),the soils of the upper horizons appeared to be classified as ML(Lean silt)and CL(Lean clay)while the soils of the lower horizons(saprolite zone)fall in SC(clayey sand),SM(silty sand),and SW(wellgraded sand)classes.Moreover,the results demonstrated that the particle size of the soil was increased by depth.Comparison of results of the geotechnical tests showed that properties of residual soils are changed by variations of depth,weathering level,and type of parent rock.Considering the concentration of the number of lines and the concentration of the points of intersection,the length and dimension fractal of lineaments in the southeastern part of the study area,it is evident that this zone possesses weathering severity and soil thickness.Fieldwork data from this zone have also verified the severity of weathering conditions.The analysis of lineaments trends in different parts of the study area indicated that the lineaments with the NW-SE trend have a strong effect on weathering development.The weathering depth depends on the orientation of bedding joints with respect to the slope in the study area.Slope inclination and soil thickness are controlled by weathering and erosion processes.展开更多
Due to the shortage and poor distribution of per capita green space in the city of Mashhad, this descriptive-analytic research emphasized on practical aspects and information collection based on field survey. This stu...Due to the shortage and poor distribution of per capita green space in the city of Mashhad, this descriptive-analytic research emphasized on practical aspects and information collection based on field survey. This study was carried out using SPSS of version 19 (SPSS: the name of a family of computer software that is used for statistical analysis). To study the status of each research component, one sample T-Test was used and for comparison and ranking of research components in all regions and each region, Friedman test was applied. Accordingly, after identifying the parks in district 13 of Mashhad Municipality, six indicators of beauty, security, access, distribution-dispersion, area-scope were prioritized, examined, and analyzed. According to the results of one sample T-Test, the average of beauty component is more than the mean 5. On the other hand, significance level of this component is less than 0.05. According to this average and significance level of the test, it can be concluded with a confidence of over 95% that the status of beauty index is desirable. According to the results of Friedman test in all areas of district 13 of Mashhad Municipality, indexes of beauty, distribution-dispersion, and security are of utmost importance. As well, indexes of access (transportation), available facilities, and area-scope were respectively placed in the fourth to sixth position.展开更多
Shear wave velocity (Vs) is one of the most important parameters of a geological model to assess the site effect and the ground response. In this paper the spatial variability of shear wave velocity in Mashhad capital...Shear wave velocity (Vs) is one of the most important parameters of a geological model to assess the site effect and the ground response. In this paper the spatial variability of shear wave velocity in Mashhad capital city are investigated. For this purpose, 243 Vs profiles of different projects throughout the city were used. Based on the Vs profiles the iso-level maps of the Vs interfaces 300, 500, 750, 950 and 1200 m/s were obtained by kriging interpolation method. The best semivariogram models were obtained with changing the effective parameters and assessing the components of the models and spatial dependence. The best models for the entire interfaces were exponential. Based on these models, the spatial dependence of depth data was moderate to strong. The performance of interpolations was checked by cross-validation and its indices?i.e. mean standardized prediction errors (MSPR), root mean square prediction errors (RMSPE), average kriging standard error (AKSE), and root mean square standardized prediction errors (RMSSPE) were assessed. A trend of depth increasing towards the northeast was observed at all of the interfaces.展开更多
Weather and climate have a double-edged effect on tourism. It can be considered both as a limiting and a developing factor for tourism. In this regard, having access to precise bio-climatic information can be of high ...Weather and climate have a double-edged effect on tourism. It can be considered both as a limiting and a developing factor for tourism. In this regard, having access to precise bio-climatic information can be of high use to enhance the quality of tourism services. This study has evaluated the Bio-climatic conditions of the tourists in Mashhad, a North-Eastern city in Iran, through the use of thermo-physiological indicator of physiological equivalent temperature (PET). Studies have been done for the hours of 9:30, 12:30 and 21:30 of the local time using the statistical data of the period between 1978 and 2007. According to the results, the longest period of climatic-comfort-hours is around 21:30 (mainly in June, July, and August), and the shortest duration of climatic-comfort-hours is around 9:30 (sporadically assessed in April, May and October). The Bio-climatic conditions during the Nowruz Holidays are only comfortable in the evenings. Especially, there is the challenge of cold stress in the mornings and more specifically, at nights. However, the best condition of the whole assessed times in summer holidays (that is June 22nd to September 23rd) is at 21:30. Summer days are not ideal for tourism due to the heat stress. The daily change of PET index shows a Gaussian curve, the peak of which (indicative of too much heat stress) shows July, and non-stress condition can be seen on both sides of this curve.展开更多
Preterm birth and associated conditions are one of the biggest killers of children in the worldwide. In this regards, current study aimed at investigation of the relationship between air pollutants of Pm10, CO, O3, an...Preterm birth and associated conditions are one of the biggest killers of children in the worldwide. In this regards, current study aimed at investigation of the relationship between air pollutants of Pm10, CO, O3, and SO2 and preterm birth occurrences recorded in Imam Reza (PUH) Hospital of Mashhad for a five-year period from 2007 to 2011. The results of quantile regression showed that the amount of atmospheric pollutants have an important role in rising preterm births. In this way, the pollutants of Pm10 and CO have revealed the strongest effect on preterm birth occurrences especially for the last three months of pregnancy. Moreover, preterm births mostly have occurred in warm seasons of spring and summer, while the seasonal average of pollutants concentration, excepting O3 pollutant, has shown rising in cold seasons of autumn and winter. However, reducing air pollution could also be effective in reducing preterm births across the world.展开更多
Preservation of teeth until old ages indicates oral health status. Improving life expectancy in developing countries makes teeth care an important topic. This study assessed reasons of tooth extraction (TE), oral heal...Preservation of teeth until old ages indicates oral health status. Improving life expectancy in developing countries makes teeth care an important topic. This study assessed reasons of tooth extraction (TE), oral health determinants and demographic factors of permanent TE in Iranian adults. Adult people who referred to dental clinic of Mashhad Medical University in 2012 for dental extraction and lived in Mashhad city, participated in this study by convenient sampling method after obtaining informed consent. Demographic characteristics, oral health status, health habit and reasons of TE of participants were assessed. Data were analyzed by SPSS11.5 by Chi-Square, T-Test, ANOVA, Mann-Whitney and Kruskall-Wallis tests. Totally 254 people participated (383 extracted teeth) that 55% were female. Mean age of participants was 39.3 years;females were 6.1 years younger than males. The main reason of TE was dental caries (55.1%), following by impaction. There was significant difference between average times of tooth brushing in both sexes, but difference was not shown in sugar intake. Except in people with college degrees that dental caries is the main cause of TE. With increase in life expectancy to more than 70 years old in Iranian, the age of TE especially in women is younger than expected. The most common cause of TE is dental caries that seem in spite of improving health indexes in Iran, poor oral hygiene remains as a problem. There is no significant difference between frequency of sugar intake and level of education that indicates unhealthy dietary habits related to tooth decay.展开更多
文摘Characterizing the subsurface structure is an important parameter for the improvement of seismic hazard assessment.Due to the tectonic complexity of the earth,some deep fractures do not reach the earth's surface and are not detectable with visual analysis.Therefore,the lack of knowledge of faults and fractures can result in disasters,especially in urban planning.Many geophysical methods can be used to estimate subsurface structure characterization.However,a more reliable method is required to assess seismic hazards and reduce potential damage in metropolitan areas without destroying buildings and structures.This paper aims to identify hidden faults and structures using shear wave velocity sections.To do this,surface wave dispersion curve was extracted from the vertical component of microtremor array recording using the spatial autocorrelation(SPAC)method in two profiles and 13 array stations(perpendicular to the altitudes)to obtain shear wave velocity structure(Vs)in the west of Mashhad,northeast of Iran.The results of shear wave velocity profiles(Vs)indicate sudden changes in the thickness of sediments.This can be related to the displacement of a normal fault in this area causing the bottom rock to fall and an increase in the alluvial thickness in the central part of the plain.The velocity in the floor rock is 2000 meters per second in this area.According to the surface outcrops and water wells data,its material is slate and Phyllite metamorphic rocks that are exposed in the adjacent heights.Besides,the seismic profile results were well consistent with electrical resistance data and well logs indicating that the tool array method is flexible,non-invasive,relatively fast,and effective for urban areas with satisfactory accuracy.
文摘Residual soils are weathering products of rocks that are commonly found under unsaturated conditions.The properties of residual soils are a function of the degree of weathering.A series of index properties,engineering properties and geophysics survey examinations were performed on residual soils from two major geological formations in Iran.In the present research,the index properties of residual soils in the south of Mashhad city in Iran are investigated.Natural and artificial trenches were analyzed for evaluating the weathering profiles and collecting soil samples.Disturbed and undisturbed samples were obtained from each of the soil profile horizons resulting from weathering of different parent rocks.Subsequently,physical properties and mechanical properties of the soil samples were determined in accordance with ASTM standards.Also,the mineralogical composition,chemistry,and texture of the soil were evaluated in 51 profiles.The field observations showed the difference in the weathering profile of residual soils deposited on various rocks(igneous,sedimentary,and metamorphic).These profiles mainly consisted of two horizons includingresidual soil on top and saprolite at the bottom.The results of laboratory tests and geotechnical data showed that the properties of residual soil samples change by depth.Moreover,depending on the type of origin rock,the properties are different in various types of residual soils.In most of the samples,the moisture content of soil horizons was also increased by depth.Based on the unified soil classification(USCS),the soils of the upper horizons appeared to be classified as ML(Lean silt)and CL(Lean clay)while the soils of the lower horizons(saprolite zone)fall in SC(clayey sand),SM(silty sand),and SW(wellgraded sand)classes.Moreover,the results demonstrated that the particle size of the soil was increased by depth.Comparison of results of the geotechnical tests showed that properties of residual soils are changed by variations of depth,weathering level,and type of parent rock.Considering the concentration of the number of lines and the concentration of the points of intersection,the length and dimension fractal of lineaments in the southeastern part of the study area,it is evident that this zone possesses weathering severity and soil thickness.Fieldwork data from this zone have also verified the severity of weathering conditions.The analysis of lineaments trends in different parts of the study area indicated that the lineaments with the NW-SE trend have a strong effect on weathering development.The weathering depth depends on the orientation of bedding joints with respect to the slope in the study area.Slope inclination and soil thickness are controlled by weathering and erosion processes.
文摘Due to the shortage and poor distribution of per capita green space in the city of Mashhad, this descriptive-analytic research emphasized on practical aspects and information collection based on field survey. This study was carried out using SPSS of version 19 (SPSS: the name of a family of computer software that is used for statistical analysis). To study the status of each research component, one sample T-Test was used and for comparison and ranking of research components in all regions and each region, Friedman test was applied. Accordingly, after identifying the parks in district 13 of Mashhad Municipality, six indicators of beauty, security, access, distribution-dispersion, area-scope were prioritized, examined, and analyzed. According to the results of one sample T-Test, the average of beauty component is more than the mean 5. On the other hand, significance level of this component is less than 0.05. According to this average and significance level of the test, it can be concluded with a confidence of over 95% that the status of beauty index is desirable. According to the results of Friedman test in all areas of district 13 of Mashhad Municipality, indexes of beauty, distribution-dispersion, and security are of utmost importance. As well, indexes of access (transportation), available facilities, and area-scope were respectively placed in the fourth to sixth position.
文摘Shear wave velocity (Vs) is one of the most important parameters of a geological model to assess the site effect and the ground response. In this paper the spatial variability of shear wave velocity in Mashhad capital city are investigated. For this purpose, 243 Vs profiles of different projects throughout the city were used. Based on the Vs profiles the iso-level maps of the Vs interfaces 300, 500, 750, 950 and 1200 m/s were obtained by kriging interpolation method. The best semivariogram models were obtained with changing the effective parameters and assessing the components of the models and spatial dependence. The best models for the entire interfaces were exponential. Based on these models, the spatial dependence of depth data was moderate to strong. The performance of interpolations was checked by cross-validation and its indices?i.e. mean standardized prediction errors (MSPR), root mean square prediction errors (RMSPE), average kriging standard error (AKSE), and root mean square standardized prediction errors (RMSSPE) were assessed. A trend of depth increasing towards the northeast was observed at all of the interfaces.
文摘Weather and climate have a double-edged effect on tourism. It can be considered both as a limiting and a developing factor for tourism. In this regard, having access to precise bio-climatic information can be of high use to enhance the quality of tourism services. This study has evaluated the Bio-climatic conditions of the tourists in Mashhad, a North-Eastern city in Iran, through the use of thermo-physiological indicator of physiological equivalent temperature (PET). Studies have been done for the hours of 9:30, 12:30 and 21:30 of the local time using the statistical data of the period between 1978 and 2007. According to the results, the longest period of climatic-comfort-hours is around 21:30 (mainly in June, July, and August), and the shortest duration of climatic-comfort-hours is around 9:30 (sporadically assessed in April, May and October). The Bio-climatic conditions during the Nowruz Holidays are only comfortable in the evenings. Especially, there is the challenge of cold stress in the mornings and more specifically, at nights. However, the best condition of the whole assessed times in summer holidays (that is June 22nd to September 23rd) is at 21:30. Summer days are not ideal for tourism due to the heat stress. The daily change of PET index shows a Gaussian curve, the peak of which (indicative of too much heat stress) shows July, and non-stress condition can be seen on both sides of this curve.
文摘Preterm birth and associated conditions are one of the biggest killers of children in the worldwide. In this regards, current study aimed at investigation of the relationship between air pollutants of Pm10, CO, O3, and SO2 and preterm birth occurrences recorded in Imam Reza (PUH) Hospital of Mashhad for a five-year period from 2007 to 2011. The results of quantile regression showed that the amount of atmospheric pollutants have an important role in rising preterm births. In this way, the pollutants of Pm10 and CO have revealed the strongest effect on preterm birth occurrences especially for the last three months of pregnancy. Moreover, preterm births mostly have occurred in warm seasons of spring and summer, while the seasonal average of pollutants concentration, excepting O3 pollutant, has shown rising in cold seasons of autumn and winter. However, reducing air pollution could also be effective in reducing preterm births across the world.
文摘Preservation of teeth until old ages indicates oral health status. Improving life expectancy in developing countries makes teeth care an important topic. This study assessed reasons of tooth extraction (TE), oral health determinants and demographic factors of permanent TE in Iranian adults. Adult people who referred to dental clinic of Mashhad Medical University in 2012 for dental extraction and lived in Mashhad city, participated in this study by convenient sampling method after obtaining informed consent. Demographic characteristics, oral health status, health habit and reasons of TE of participants were assessed. Data were analyzed by SPSS11.5 by Chi-Square, T-Test, ANOVA, Mann-Whitney and Kruskall-Wallis tests. Totally 254 people participated (383 extracted teeth) that 55% were female. Mean age of participants was 39.3 years;females were 6.1 years younger than males. The main reason of TE was dental caries (55.1%), following by impaction. There was significant difference between average times of tooth brushing in both sexes, but difference was not shown in sugar intake. Except in people with college degrees that dental caries is the main cause of TE. With increase in life expectancy to more than 70 years old in Iranian, the age of TE especially in women is younger than expected. The most common cause of TE is dental caries that seem in spite of improving health indexes in Iran, poor oral hygiene remains as a problem. There is no significant difference between frequency of sugar intake and level of education that indicates unhealthy dietary habits related to tooth decay.
