جستجوی مقالات مرتبط با کلیدواژه « Yazd » در نشریات گروه « علوم پایه »

Nowadays, considering the side effects of synthetic antibiotics and the increase in drug resistance, it is a necessity to replace them by natural compounds as safe sources. Thus, studies have been carried out on the medicinal properties of essential oils of different Ferula L. species, but there was no report on Ferula tabasensis Rech. f. as an Iranian endemic species. In this research, the leaves and flowers of Ferula tabasensis were harvested from its main habitat (between Kharanaq and Saghand – elevation 1570 m) at the full-flowering stage in the spring of 2021. The essential oils were extracted by hydro distillation method (Clevenger apparatus and GC and GC/MS were used to analyze chemical constituents. The antimicrobial activity of essential oil was evaluated by minimum inhibitory concentration (MIC) determination by broth dilution method and the growth inhibitory zone diameter (mm) was also measured. The yields of essential oils from the leaves and flowers of the plant were 0.3% and 0.5%, respectively. The results showed that bornyl acetate (34.2% and 35%) and α-pinene (12.2% and 8.4%) were identified as major compounds of essential oil from leaves and flowers, respectively. Also, citronellol (15.5%) was another main constituent found in the essential oil of the flowers of Ferula tabasensis. Both essential oils had good antimicrobial activity against the tested microorganisms, except E. coli. It seems that antibacterial activity can be mostly attributed to the main compounds of essential oils in the leaves and flowers of the plant and, thus, they can be considered as alternatives to synthetic antibiotics.

The Khoud copper skarn ore deposit, located about 50 km northwest of the Taft City in Yazd province, is situated within the middle part of the Urumieh-Dokhtar magmatic belt. The geology of this ore deposit is dominated by upper triassic carbonate units that were intruded by an Oligo-Miocene granodiorite porphyry. Garnet and garnet-pyroxene skarn zones had replaced marble and limestone in the contact zone with the granodiorite porphyry. In this paper, δ18O and δ13C values of calcites from limestone (sedimentary calcite), marble (metamorphic calcite), and skarn calcite have been reported and interpreted. The data shows that systematic depletion of 18O and 13C has occurred in the metamorphic and skarn calcites. The skarn calcites show the highest depletion compared to calcite in marble and limestone. Calculated models showed that this systematic isotopic depletion in the study calcites can be attributed to a magmatic fluid infiltration and fluid-induced decarbonation. Depletion in 18O and 13C of various calcite types of Khoud deposit can be explained by magmatic fluid (δ18Ofluid = +9.0‰) that reacted/interacted with unaltered carbonate rocks at temperatures of less than 400oC with X(CO2) lower than 0.05 and W/R ratio of 25 to 50%.

Solar radiation is very important as one of the important variables in energy balance models and plant growth simulation. Although the measurement of this variable has a relatively long history in Iran, due to the high costs of measuring devices, there is no pyranometer in many existing stations in the country, and there are problems such as its recalibration, water, and dust accumulation that exists on the sensor. Even in meteorological stations that measure radiation, there are days when radiation data is not recorded or unrealistic values outside the expected range are observed due to equipment violations or other problems.This research investigated the performance of nine machine learning algorithms including linear regression (LR), Least Absolute Shrinkage and Selection Operator (Lasso), Elastic Net (EN), K-Nearest Neighbors (kNN), Decision Tree (DT), Support Vector Regression (SVR), Random Forest (RF), Extra Trees (ET) and Gradient Boosting Machine (GBM) to estimate solar radiation in Yazd synoptic station between 2005 and 2021 with cross-validation method (kfold). The parameters of average temperature, minimum temperature, maximum temperature, sunny hours, relative humidity, and solar radiation are obtained from the National Meteorological Organization on a daily basis and extraterrestrial radiation variables, relative distance from the earth to the sun, solar inclination angle, and maximum sunny hours are calculated with existing relationships and were selected as input for the prediction models. The evaluation criteria for solar radiation estimation were MSE (Mean Square Error), MAPE (Mean Absolute Error), and determination Coefficient (R2).The results showed the coefficient of determination (R2) varies between 0.716 and 0.870 depending on the algorithm used in the training phase. In other words, in terms of the determination coefficient, all the used algorithms showed good results for predicting solar radiation. According to the results of all three criteria, it can be seen that the Support Vector Regression (SVR) algorithm has performed better than other algorithms. After the support vector regression (SVR) algorithm, the linear regression (LR) algorithm was ranked next with the MAPE of 5.04, the MSE of 1.13, and the R2 of 0.867. Also, the elastic pure regression algorithm (EN) with the highest mean absolute value of error (MAPE), the highest mean squared error (MSE), and the lowest coefficient of explanation (R2) ranked last among the nine used algorithms. After the data training phase, using the K-fold cross-validation method, the remaining 20% of the data were tested. As the results show, the MSE changes for nine machine learning algorithms are high and vary from about 3 to 9 Mj/m2/day. Its highest value was observed in the DT algorithm and its lowest value was observed in the support vector algorithm. The average value of the absolute value of the error was also in the range of 0.8 to 2.2 Mj/m2/day, and also the values of the R2 were different in the range of 0.7 to 0.9. In general, and according to the results of all three evaluation criteria, the support vector machine algorithm showed the best results in the data test stage as well as in the training stage.

Khut Copper deposit, located in west of Yazd, is one of the most important skarn deposits in Taft mining area where it is locateds in the middle part of the Urumieh-Dokhtar magmatic belt. Intrusion of Khut granodioritic stock into carbonate component of the Nayband Formation has led to the formation of Cu skarn deposit and different skarn zones. Mass changes has led to mineralogical variations in the different skarn zones. In this paper, element mass changes and element mobility in the skarn zones relative to the unaltered carbonates rocks are calculated. Results of these calculations show the most mass increase in the major elements of Si, Fe and Mn in the skarn zones. REE and the other rare elements such as Rb, U, V, Nb,Cr, Y, Cu and Zn have also shown mass increase. Enrichment value in the light rare earth elements can be attributed to the abundance of garnets and its composition, so that the amounts of light rare earth elements in the Al bearing garnets are higher than andradite garnets. In this paper, the causes of these changes and their effects are discussed by using geochemical method of mass change calculations.

In the present research the position of public participation in Yazd Great Garden plan has been evaluated. In the first stage, based on the method of qualitative analysis, through interviews with local people, the position of public participation in the stages of approval and implementation of the plan was pathologically evaluated. The results of the studies show that local people are very dissatisfied with the lack of transparency and information by the municipality during the approval and implementation of the plan. In the second phase of this study, the trend of changes in the urban landscape in the study area (from 2001 to 2020) was evaluated using landscape metrics in FRAGSTATS software. The results of this evaluation showed that, during this period, many constructions have been done in this area. The size of barren patches has increased by 283%. The size of garden-agricultural patches has decreased by 80% and the size patches of construction has increased by 196%. In general, in spite of the goals of the mentioned plan to protect the gardens, the area and connectivity of garden and agricultural patches has been reduced and fragmentation is increased. Summarizing the results shows that if public participation was used in the approval and implementation process and information was provided in a transparent manner, the goals of the project were achieved, and local gardeners acted as the supporter of the municipality in the project.

A patch is a unit of the structure of the land or almost homogeneous part of the land that has a hierarchical structure and is considered as a homogeneous and recognizable ecosystem that is completely different from its surroundings. Two parameters of size and shape of habitat patchs affect the types and number of animals in it. These two parameters are important components in the design and planning of areas for species protection. Therefore, this study has studied the relationship between two parameters of size and shape of habitat patchs in Adoroshk watershed. During the spring and summer seasons of 2019, Adoroshk animals were identified. A total of 14 species of mammals and 26 species of birds were identified in Adoroshk. The highest amount of richness, diversity and uniformity of species was observed in shrub patch and the lowest amount was observed in high density shrub and grassland spots. FRAGSTATS 4.2 software was used to calculate the metrics used in the research. Data analysis using Spearman correlation and values of species diversity from Shannon-Wiener, Simpson, Hill, Brillouin and McArthur indices, species richness with Margalf and Mann-Henick indices Calculated. The results showed that there was a significant relationship between Simpson and Brillouin diversity index and Margalf and Mann-Henick richness indices with AREA and PARA criteria. Also, a significant relationship was observed between biodiversity indicators and physical parameters of patchs at the level of one percent, and small patchs are preferred in habitat design and management for animals.

In the present research, to fully recognize the Yazd, Darreh-Zereshk copper deposit, 3-D multiple-log of the boreholes lithology, cross-sections of lithology and assay data corresponding to profiles covering the whole area and 3-D lithology model of the deposit were plotted using Rockworks software. Based on this, limestone, skarns, sandstone, diorite, granodiorite, quartzite and monzonite perform the dominant lithology of the region and the surface of the area is mostly covered by overburden, shale and lime. Depending on the deposit conditions, to estimate the deposit reserve, inverse distance squared method as a geometric method and geostatistical kriging method were used through Surpac software. According to the deposit variography using WinGslib software, the deposit has geometric anisotropy and maximum range of 130 m with azimuth zero, mean range of 100 m with azimuth 90 and minimum range of 40 m on the vertical direction with azimuth zero. After geometric modeling and producing block model of the deposit, the reserve was estimated for cut-off grades of 0.1, 0.2, 0.3, 0.4 and 0.5% copper as well as their results were compared. The results of the reserve calculation show that the difference of the calculated reserves with applied methods is relatively high, i.e. for cut-off grade of 0.1% is about 1547600 tones or 5.7%. Although, inverse distance squared method is the most accurate method among the geometric methods of reserve estimation, geostatistical kriging method considering spatial structure of the region, being unbiased and having minimum estimation variance is more accurate with higher degree of validity.

Changes in the land biosphere since 1970 are consistent with global warming: climate zones have shifted poleward in both hemispheres, and the growing season has on average lengthened by up to two days per decade since the 1950s in the Northern Hemisphere extratropic. In this research, projected change of growing season length (GSL) and the start date of the growing season over Yazd province are investigated using three GCMs (GFDL, HadGEM and MIROC5) under the RCP8.5 scenario during 2021-2040. The results indicate Yazd province will experience extended GSL in a warmer world. The thermal growing season has been projected to increase owing to the earlier onset of growth in late winter and spring. Therefore, the prolongation of GSL under the RCP8.5 is attributed to earlier onset. Future temperature and precipitation scenarios based on GFDL and HadGEM models under the RCP8.5 scenario show more unfavorable conditions for this province. Because of the sensitivity of agriculture to weather and climate conditions, these impacts can have substantial direct and indirect effects on production and profitability.

Yazd province is located in the arid and desert climate and its water resources include about 10 wetlands and artificial basins. The most important ones, for attracting birds, are the artificial basin of the Yazd city treatment plant with permanent water, and Kasehrood dam in Abarkooh city with suitable geographical location. In the present study, the avifauna of both habitats were identified and listed based on the available statistics regarding monitoring and bird counting for six years (2014-2020). The results revealed that up to 60 species are living in the treatment plant water basin and 25 in the Kasehrood dam. The highest frequency was belong to the ducks family with nine and seven species in the treatment plant and Kasehrood dam, respectively. The observed species including white headed duck, steppe eagle, lapwing, steppe pipit and black vulture have protective values based on the IUCN list. The yellow herons and tufted duck were observed and recorded for the first time in both localities. This study indicated that the Yazd treatment plant artificial basin and Abarkooh Kasehrood dam have important roles in providing habitats for waterfowls, terrestrial birds and protection of migratory birds. Therefore, management and protection of their habitats should be considered.

Mehdiabad zinc-lead-barite deposit is located in the Central Iran structural zone and about 116 km southeast of Yazd. The host rock of this deposit is Lower Cretaceous dolomitic limestone of the Taft Formation . The main ore minerals in the Mehdiabad East Ridge ore zone include hemimorphite, hydrozincite, cerussite, and chalcophanite. Ore textures are mainly replacement, brecciated, and open-space filling. As a result of supergene and weathering processes, the sulfide minerals (sphalerite and galena) have been changed to non-sulfide minerals such as hemimorphite, hydrozincite, and cerussite. Statistical analysis of geochemical data indicates that the elements in the ore could be divided into three groups: terrigenous, host rock-forming, and ore-forming elements. Formation of iron-rich dolomite, ankerite, and siderite indicates high concentrations of iron and manganese in the mineralizing fluid. Based on this study, the characteristics of the Mehdiabad deposit are very similar to the Mississippi-Valley type deposits.

Anomaly XVI-B located in Central Iran Structural Zone. The oldest rock formations in this study area are related to metamorphic rocks which are included gneiss, micaschist, amphibolite and megmatite. Mineralized intruded mass distinguished by alkaline diorite-syenite that cut Bonoshorow metamorphic complex and limestone units. Metallic mineralization is occurred in syenite, gabbro and skarn rocks. Magnetite is the most abundant mineral in anomaly XVI-B and also it has been seen as stripe, mass, disseminated and filling empty space textures. The magnetite grains are shaped to shapeless. Magnetite is oxidized near the surface and converts to hematite, goethite and other iron oxides. Another metallic mineral which are associated with magnetite are pyrite, and chalcopyrite, which have been found in quartz, actinolite, calcite, and epidotite that come with various forms within host rocks, syenite, gabbro, and skarn. According to the graphs of rare earth elements in iron mineralization and intruded units indicates the possible similarity of the source of iron mineralization with intruded mass. The grade of iron oxide in ore deposit varies between 25 and 75 percent. The iron element has a negative correlation with oxide of titanium oxides, magnesium, manganese, phosphorus, potassium and sodium. Based on cobalt relationship with nickel, chromium - nickel, and chromium - vanadium, so anomaly XVI-B iron deposit is related to the hydrothermal deposits. Due to the ratio of Al / Co and Sn / Ga, anomaly XVI-B is recognized as a skarn type deposit. Based on the scattering patterns of the rare elements, anomaly XVI-B is more similar to the skarn type deposit. Geological and mineralogical evidence, as well as the geochemical properties of the magnetite, indicate that skarn deposit is source of iron mineralization. Iron is transported by the hot fluids that come from intruded units that accumulates between boundary of metamorphic and marble units. δ34S value is between 21.24% - 22.27%. The source of Sulphur isotope is meteoric and ancient marine water. As a result, the accompaniment of magnetite with pyrite can be found that the source of magnetite is identical with pyrite.

In the southeast of Nir, south of Yazd Povince, several acidic volcanoes  rocks are exposed and form the youngest volcanic rocks in this region with dacite-rhyodacite composition. These rocks are composed of plagioclase, hornblende, biotite and quartz phenocrysts with trachytic and hyallomicrolithic porphyry texture. Based on geochemical data, the magmatic affinity of these rocks is calc-alkaline with enrichment of LILE and depletion of HFSE. These characteristics with steep decrease pattern of rare earth elements and negative anomaly of HFSE, such as Nb, Ti and P, indicate the formation of magma in active continental margin. Higher levels of SiO2, Sr, Sr/Y, and La/Yb with low levels of MgO, Yb, and Y, indicate high silica adakite affinity. It seems that the formation of parental magma of these rocks is consequence of the melting of garnet amphibolite or eclogite rocks of subducted metamorphosed Neotethys oceanic lithosphere in the Central Iran- Arabian plate collision zone during the Neogene time.

The Bidakhavid mine is located on the western margin of the Shirkouh Batholith in the Central Iran and as a part of Urumieh-Dokhtar magmatic belt. This mine is the result of alteration of quaternary alluvial deposits. The main unit of the Bidakhavid mine is the iron oxide cement-semi-hardened alluvial-abrasive sediments with main minerals, including quartz, biotite, K- feldspar, altered plagioclase and clay minerals. Significant geological aspects are the emission of sulfur gases and the deposition of natural sulfur in surface of Quaternary alluvial deposits. The presence of efflorsence minerals such as halotrichite, confirm a fumarole region and the release of volcanic sulfid gases associated with young volcanism in the Dehshir fault zone. Iron sulfate efflorsence minerals are produced by pyrite oxidation and the formation of acidic environments on the surface of the groundwater table. The occurrence of this highly acidic environment has led to the occurrence of alteration minerals such as pyrite, sericite, rectorite, illite and jarosite.

Habitat assessment is one of the pillars of wildlife management and protection. In the study, the evaluation of Pika habitat in Adoroshk watershed was performed using the maximum entropy algorithm model (MaxEnt). According to the principles of cartography from the geographic reference map topography to extract the boundary of the region, the digital height model for the preparation of the classified map (Dem) of elevation changes, Slope and geographical domain were used. In order to prepare the environmental layers to enter the model MaxEnt, ArcGis software version 10.3 was used. Sampling was performed using random linear transect method and binoculars through direct observation of cheeks and indexes in spring and summer of 2019 and the number 33 points of Pika,s presence were recorded by GPS. Validation of the model was performed using the area under the curve (AUC) and the usefulness of the variables by analyzing the Jacknife test. The results showed that the desirability of Paika habitat in the Adoroshk watershed is mainly in rocky and mountainous areas with grass and shrubs at altitudes above 2500 meters above sea level and slopes. It is more than 50%. The climate was considered suitable for temperate pike. Favorable areas for Paika constitute 275 hectares (17.46%) of the habitat. It was also found that in Adoroshk, Paikas prefer the western slope.

Feathers as an excellent way to monitor trace metals in the environment from the 1960s have already been used. The aim of this study is using feather of laughing dove (Streptopelia senegalensis) as an indicator of urban environmental pollution.

The concentration of Cadmium, Lead, Copper and Zinc were evaluated from 58 laughing dove's feather samples from 19 different locations within the city of Yazd. Chemical digestion and atomic absorption spectrometer was used for measuring the concentration of trace metal. Weighing method by 0.001 g accuracy digital scale were used to study the index of two wing asymmetry.

Mean concentration of Lead, Cadmium, Copper and Zinc were 20.13 ± 1.27 μg g-1, 0.85± 0.04 μg g-1, 15.56 ± 0.28 μg g-1 and 209.72 ± 8.77 μg g-1. Due to heterogeneity of human activity and structure in urban environment the concentration of trace metals (lead, cadmium and zinc) showed significant differences in different local scale regions. In this study correlation was observed between Lead and Cadmium with Zinc.

Correlation pattern could simply result from correlated concentrations of these metals in the environment and could be a kind of positive feedback protection against Lead and Cadmium pollution. The results showed considerable trace metals absorption by laughing dove's feather that caused by human activity and efficiency of laughing dove's feather as an indicators of trace metal pollution in urban environment.

The evolutionary history of the Sanandaj-Sirjan zone has been influenced by two extensional and compressional regimes that have caused rifting, subduction, collision and its final closure.The study area is located in Esfandabad city of Yazd province. The sequence contains dark colored andesitic, rhyolitic and basaltic lava with interlayers of volcanoclastic and sedimentary units. The volcanic rocks detected contain aphanitic textures and have dark gray to black color with oxidized surface, fractures and pores. These volcanic rocks have a layered flow and are mostly seen as dome-shaped structures and are sometimes in the form of dikes. Another characteristic of this group of rocks is the green color obtained from the secondary minerals of chlorite and epidot, as a result of the alteration applied to them. The volcanoclastic rocks are mainly fine-grained and welded purple tufts.

In order to achieve the aim of this study, after descriptive studies, field operations were performed in three stages and 100 samples were taken from the desired outcrops and thin sections were prepared. After petrographic studies, less altered samples were selected and sent to the GeoLeb Laboratory in Canada for geochemical analyzing using XRF, ICP-MS and ICP-IAS methods. Age studies have been conducted at the Caltech Institute in California.

In microscopic studies, the dominant texture in basaltic rock is porphyry, consisting of plagioclase, olivine and pyroxene in a fine-grained matrix composed of plagioclase, epidote, chlorite, sphene and opaque minerals. Andesitic rocks have microporphyric and seriate textures consisting of plagioclase, in a fine grained matrix consisting of plagioclase, pyroxene, quartz, epidote, carbonate and chlorite alteration products and opaque minerals. Rhyolite rocks have a microcrystalline to hyalline texture consisting of quartz, alkali feldspar and plagioclase. Evidence such as sosoritization of plagioclase, filling of cavities by chlorite and zeolite, idingitizated or chlorinated olivine and uralite pyroxene crystals indicate the performance of metamorphic phenomena in the studied rocks.

Based on geochemical data, the studied rocks have basaltic and trachydacite composition with tholeitic and calcalkaline affinity. The pattern of spider diagrams in the study area are almost the same but with a different frequency. The enrichment of Th and U in these diagrams can be attributed to crustal contamination and enrichment of LREE to low melting rates of mantle source (less than 15%), or contamination of magma with crustal materials. The negative Eu anomaly is related to the differentiation of plagioclase during magmatic crystallization or its persistence at the source when H2O activity is low. In the tectonic setting diagrams, which are used to separate the intra-plate basalts from other tectonic environments, the samples are located in the intra-plate field (WPB). Geochemical studies show an asthenospheric mantle source that has been affected by crustal contamination and crystalline differentiation. Petrographic evidence, such as the presence of porphyric texture in volcanic rocks in the area, indicate that magma has stopped in crustal chambers and contaminated it. Geochemical studies showed that trachydacite rocks form from5% melting of garnet-lorzolite and basaltic rocks produced compose from 20% melting of a spinel-lerzolite origin. U-Pb dating studies of trachydacite presents 240+ 6.6 ma age equivalent to the lower triassic which match the opening and formation of neotethys ocean in permotriass.

This study tries to evaluate the geological properties of a travertine spring and its related deposits. The identification of sedimentary facies of springs could be applied as a method to distinguish the type of travertine springs. Therefore in this study, that method has been used for the determination of the type of the spring. Results obtained from facies analysis reveal 13 sedimentary facies that could be categorized into two groups including organic facies which contain five facies and abiotic facies containing eight facies. These facies show the character of hydrothermal spring and set the spring in the thermogenic group. The chemical composition analysis of the spring water represents the facies of NaCl, Na-Ca-SO4-Cl can be considered to be precise chemical facies. The presence of calcium and sulfate as the second most frequent ions, after sodium and chloride, may initially indicates the existence of gypsum or anhydrite deposits in this area. On the other hand, given the absence of sulfate-bearing sediments in this region, it can be concluded that the interaction of water and magmatic systems was the most important source of sulfate in the spring water. Based on the rock mechanical properties of the travertine, it was revealed that with increasing age of the sediments their consolidation degree increases. The hardness of sediments shows an increasing trend by increasing distance from the spring vent.