dr. mohammad hossein fathi

Iran is located in one of the most critical regions of the world called the Middle East. Due to its convenient location and abundant energy reserves, this region has always been of interest to foreign countries, led by the United States. This has led to numerous US interventions and the establishment of numerous military bases around Iran, especially after September 11th incident. Continuous monitoring of these bases and related facilities is one of the most important deterrents that can be done by remote sensing knowledge. One of the remote sensing techniques is the synthetic aperture radar, which has been considered in recent years, while the Sentinel-1 satellite launched in 2014 by the European Space Agency uses the same technique. One of the applications of this satellite, which is introduced in this article, is the detection of Patriot MIM-104 systems. This is done by combining the VV and VH polarizations with two images taken during the satellite's day and night transitions from a single point, which are represented by X-shaped lines where the Patriot systems are located. The images related to this satellite are also processed by Google Earth Engine system, which saves considerable time in analysis and increases the accuracy of the results due to the minimization of human error. The results showed that in the regions around Iran and especially in the Arab countries of the Persian Gulf, there are at least 16 active Patriot systems, which indicates its great development in recent years and shows the need for continuous monitoring of these systems.

Sport is a universal phenomenon and with its expansion, people and various strata of a society benefit from its benefits, so to maintain health and physical and mental growth, giving importance to sports has a key role in improving the quality of life and increasing the standard of living of citizens. Iranian architecture has a high status in the history of Iran and from the past to the present have had different characteristics that distinguish it from other styles and contexts of buildings. These components include scientific geometry and innovative arts derived from a person's spiritual thoughts. According to the types of basic, theoretical, applied and scientific research, the present research is applied in terms of purpose. There will be a library and a field that will eventually lead to design

Exercise and healthy recreation is one of the most important strategies of industrial man today to maintain health and physical and mental growth and creates a large segment of society for some time to exercise, watching sports competitions. A modern stadium is not just a place to watch sports events, but it has become an exciting and unforgettable part for the spectators. The design principles of this series are based on creating an indoor space and at the same time instilling a sense of open and free environment for players and spectators. On the other hand, modern technology has been used to achieve a light structure, and when stadiums are built strategically and in accordance with design principles and criteria, they attract more spectators than the events they host, and not only that. It is a source of income but also as a unique added value in sports affairs. According to the types of basic, theoretical, applied and scientific research, the present research is of applied type. The research method in the present study is a research-analytical method that ultimately leads to design

Defense and security organizations operate in a very complex and unstable environment. Long-term defense planning encourages thinking about possible situations and helps defense organizations prepare for the future to improve their strategy by providing insights into possible future dangers. The main purpose of this study is to study the geomorphological features of Minab and Sirik areas in the east of the Strait of Hormuz and their impact on the development of territorial defense strategies. The type of applied research and its nature is analytical-descriptive. Data were collected in the form of libraries - documentary and survey and its data were qualitative and quantitative. The statistical population includes 24 elites and experts in defense and security issues. The coefficient of criteria was determined based on the Likert spectrum. Using SWOT analytical tool, 34 indicators (strengths 8, weaknesses 9, opportunities 8 and threats 9) were evaluated and evaluated by relevant experts. The Quantitative Strategic Planning Matrix (QSPM) was used to select the optimal strategy from the strategies obtained from SWOT analysis. The results of the SWOT model suggest the (WO) strategy as the optimal strategy in the Minab and Sirik regions. At the same time, in prioritizing the review strategy using the model (QSPM), the priority and superiority of the strategy is to use and deploy advanced defense, radar and eavesdropping systems, parallel to the shoreline and the points that create maximum frequency range over other review strategies.

Diagnosis and classification of landslides is a critical need in the risk analysis before and after the disaster. And primarily through land surveying or traditional interpretation of images was done. In this paper to identify and classify types of object-oriented approach landslide has been paid. The data used in this study consisted of false color images obtained from satellite data Resourcesat-1 with spatial resolution of 5.8 meters and digital elevation models with 2.5-meter resolution satellite image of 10 meters of Cartosat-1 was used. This method was used for the North West basin and then used without further reforms in the eastern part of the basin. A total of three sliding using this method accurately identified 71.11% and 91.4% classification accuracy has been detected. In this way, the landslide early detection of high accuracy and speed, hence has great potential to assist in risk analysis, disaster management and decision making process after the earthquake or heavy rainfall, can be used related entities, including crisis management headquarters, natural resources and watershed institutions.

Mass movements and landslides are considered the most destructive natural hazards. The study predicts landslide location using conditional probability theory (Bayesian theorem), on the southern edge of the Ahar drainage basin (From Nasirabad to Sattar Khan dam),, on the landslide occurred in the past by the object-oriented approach extracting and identifying been conducted. Using Bayesian probability theory correlation between parameters and landslide areas (two-thirds of landslide areas) to determine the weight of all categories of parameters were obtained. According to the map obtained by any of the parameters weight class, class of high silt old alluvial terraces are in layers, average pasture land in between classes, directions north and northwest, steep grade 5-25 the distance of 270-125 meters from the river greatest impact on weight and landslides in the area. The accuracy of landslide susceptibility maps using a third (12 points slip) landslide areas were evaluated. The result showed that the model with the predictability and kappa coefficient 0/93   and 0/945 percent of high and very high risk of landslides in class acceptable accuracy in evaluating and landslide susceptibility mapping.

IntroductionIranian territory has the main prerequisites for the occurrence of a wide range of landslides due to its mountainous topography, tectonic activities, high seismicity, and different geological and climatic conditions. Therefore, reducing the effects of natural disasters, particularly landslides, is one of the key challenges for land-use planners and policymakers in this field. In this study, the southern side of the Ahar Chai basin from Nasirabad Village to Sattarkhan Dam is evaluated for the probability of the landslide occurrence. This region is highly susceptible to landslide occurrence because of the extensive manipulation and its natural conditions. Indeed, the occurrence of the large shallow landslides in this region is an indication of this susceptibility. In this study, Linear Regression Model has been used to prepare the landslide zonation.
MethodologyThe study area was the southern sides of the Ahar Chai River, from Nasirabad village in Varzaghan to the Sattarkhan Dam, with an area of 128 km2. In order to study the potential of the landslide occurrence in this region, nine main factors including slope, slope direction, lithology, land use, precipitation, distance from the fault, distance from the river, distance from the road, and vegetation were identified. The model which was used in this study was Logistic Regression. This model is one of the predictive statistical methods for dependent variables in which zero and one respectively indicate the occurrence and non-occurrence of landslides. In addition, instead of being linear, the regression of the variables is S-shaped or logistic curve and the estimations are in the range of zero-one. Indeed, values close to zero indicate the low probability of the occurrence and values close to one indicate the high probability of the occurrence.
DiscussionIn Logistic Regression model, after entering the data into the Logistic Regression model and using the effective parameters in Idrisi software, the coefficients of the model were extracted. A value of 965, which represents a very high correlation between the independent and dependent variables, was obtained for the ROC index. After determining the validity of the Logistic Regression model, using the above indicators, landslide sensitivity zonation map was prepared. In the present model, the land use factor with the highest coefficient was the best predictive variable in determining the probability of the landslide occurrence in this region. In addition, the SPI index and the distance from the fault had respectively the second and third highest coefficients. After zoning the landslide, the slip area was calculated for each class and its results showed that zones with highest risk had the lowest area percentage and these areas were located in the western slopes.
ConclusionThe results showed that while land use, lithology factors, and SPI index with positive coefficients had higher correlation, the other factors with negative coefficients had lower correlation. Based on the map, the western, southern, and the north-eastern parts of the region have the highest potential for landslide occurrence. Furthermore, the high value of the ROC index and its proximity to number one indicates that landslides in the study area have a strong correlation with the probability values derived from the Logistic Regression Model. In addition, the assessment of the SCAI scaling hazard zonation map shows that there is a high correlation between the hazard map with the existing slip points and the field observations of the area. It can be said that, in addition to the natural factors, some human factors including unstructured road construction may play an important role in the occurrence of the landslides. It is also necessary to avoid making changes in the ecosystems and land use. Finally, any policies to construct structures should be commensurate with the geomorphologic and geological conditions.

Ceramic dental materials have been considered as alternatives to metals for dental implants application. In this respect, zirconia tetragonal stabilized with %3 yttrium, is of great importance among the ceramic materials for endosseous dental implant application. Because of its good mechanical properties and color similar to tooth. The aim and novelty of this study was to design and prepare Y-TZP nano-composite to reduce the degradation process at low temperature by alumina addition and maintaining submicron grain sized. Also, flexural strength of nano-composite samples was evaluated. Toward this purpose, alumina-Y-TZP nano-composites containing 0–30 vol% alumina (denoted as A-Y-TZP 0-30) were fabricated using α-alumina and Y-TZP nano-sized by sintering pressure less method. The synthesized samples were characterized using x-ray diffraction, field emission scanning electron microscopy equipped with energy dispersive x-ray spectroscopy techniques. Nano-composite samples with high density (≥96%) and grain sized of ≤ 400 nm was obtained by sintering at 1270 °C for 170 min. After low temperature degradation test (LTD), A-Y-TZP20 and A-Y-TZP30 not showed monoclinic phase and the flexural strength in all of samples were higher than A-Y-TZP0. It was concluded that the grains were remained in submicron sized and A-Y-TZP20 and A-Y-TZP30 did not present biaxial strength reduction after LTD test.

IIn this work, cobalt-based alloy/ nano bioactive glass (NBG) composites with 10, 15 and 20 wt% NBG were prepared and their bioactivity after immersion in simulated body fluid (SBF) for 1 to 4 weeks was studied. The scanning electron microscopy images of two- step sintered composites revealed a relatively dense microstructure the density of which decreased with the increase in the NBG amount. Microstructural analysis as well as energy dispersive X-ray analysis (EDX) revealed that after 1 week of immersion in SBF, a small amount of calcium phosphate phases precipitates on the surface of the composite samples. After 2 weeks of immersion, a considerable amount of cauliflower-like shaped precipitations was observed on the surface of composites. The observed peaks in the Fourier transform infrared (FTIR) spectroscopy of the composite samples in SBF immersed for 4 weeks were assigned to hydroxyapatite. Therefore, a hydroxyapatite layer has been possibly formed on the surface of the composite samples during immersion in SBF. Cell culture results indicate that unlike the Co-based alloy, the Co-based/NBG composites are bioactive and bone cells could be vivid and grow on their surfaces, promising their possibility for implant applications.

Flood is one of the most common natural worldwide hazards that causes enormous losses of life and property throughout the world. Therefore, the development of flood mapping forecast models is curial in decision making before the flood and for the after flood management. The aim of this study is to determine the flood hazard zones in the khiav Chai basin using the network analysis process. To implement this model in the area under study, various data such as rainfall, land use, slope-morphological characteristics such as convexity (profile curvature) convergence divergence slopes (plan curvature), steep slopes, vegetation index (NDVI), distance from major rivers and drainage network density were considered. The results obtained from the network Analyzer model shows the fact that more than 15 percent of the area affected by the floods with very high potential risk of occurrence are mainly located at the bottom of the basin. These levels are often less than 35% in slope, with low vegetation density profiles, converged areas with concave surfaces, and areas near rivers. Analysis of the final weights derived from the AHP in relation to flood risk shows that the slope of the geological formations operating by 0/99, and 0/822 value, have the highest impact and influence, regarding the high degree of control and influence they have on the amount of runoff and discharge of the surface area. The importance and influence of the SPI with 0/226 and 0/065 STI are of less important compared to other factors.

Wear and erosion are the main reasons for destruction of many industrial components. In many cases، ceramic coatings produced by plasma spraying technique improve wear and erosion performance of industrial components. In this study، it was attempted to design and prepare an optimized composite coating of Alumina-Titania via plasma spraying technique using various parameters of plasma input power، and to study the influence of morphology، microhardness and elastic properties of prepared coatings on their erosion behaviour. Characterization of prepared coatings was performed using X-ray diffraction (XRD) technique and scanning electron microscope (SEM). The elastic properties of coatings and the porosity and gamma alumina phase in their structure were also investigated. Vickers hardness test was performed in order to measure the microhardness of coatings. The results showed that the elastic properties have the greatest influence on the erosion performance of coatings. It was also shown that the input power of 28 kW causes an increase in both the microhardness and elastic properties of coatings simultaneously.

Lake Urmia in the northwestern corner of Iran is one of the largest permanent hyper saline lakes in the world and the largest lake in the Middle East. It extends as much as 140 km from north to south and is as wide as 85 km east to west during high water periods. Qualitative and quantitative degradation of water resources is one of the major challenges in the way of sustainable development، Baghvand et al.، 2010; Nasrabadi et al.، 2010a; Nasrabadi et al.، 2010b; Rowshan et al.، 2007; Serbaji et al.، 2012; Guinder et al.، 2012; Li et al.، 2012; Siddiqui، 2011; Pei et al.، 2011; Ying et al.، 2011،. Features and phenomena in the earth’s surface have been changed over time; the lakes as one of these features and due to having a closed environment are not considered as an exception. Due to climatic changes such as reduced rainfall، increased temperature and also uncontrolled use of surface water resources in watershed areas، distinguished changes are exposed، Sadatipour et al.، 2012; Sandeep et al.، 2012; Madani et al.، 2012; Mirbegheri et al.، 2012; Arias et al.، 2012،. Monitoring such changes should be considered as an important issue in the national and regional development and natural resource management. Currently، monitoring the coastal areas and extraction of water at different intervals is regarded as an infrastructural research interest due to the significance of coastal zone management and dynamic nature e of such sensitive ecological environments، Reveshty and Maruyama، 2010; Nasrabadi et al.، 2009; Pamer et al.، 2011; Kavian et al.، 2011; Karbassi et al.، 2011; Mortazavi and Sharifian، 2011; Lei et al.، 2011; Hudak، 2011،. Urmia lake is the twentieth largest lake of the world and at the same time one of the most unique and invaluable global water ecosystems، Karbassi، et al.، 2010; Ahmadi et al.، 2011; Ahmadzadeh Kokya et al.، 2011; Farzin et al.، 2012، . The lake’s surface area has been estimated to have been as large as 5620 km2 but since 1989 it has generally been declining and was estimated from satellite data to be only 2032 km2 in August of 2011، Land sat data،. The decline is generally blamed on a combination of drought، increased water diversion for irrigated agriculture within the lake’s watershed and mismanagement. The main sight of this study are to Assessment and analyze of Urmia water levels fluctuation and increasing salt area، to model the lake surface fluctuation regime by linking the observed data to satellite data in the north west of Iran. Lake Urmia is an endorheic or terminal lake meaning that water leaves the lake only by evaporation. As is generally the case، this leads to a saltwater body and in the case of Lake Urmia، salinity is quite high. The lake is bounded between 37°5´ -38°16´ latitudes and 45°01´ - 46°longitudes at 1275 m above sea level. Its surface area ranges from4750 to 6100 km2 and the average and greatest depths account for 6 and 16 m، respectively. In order to study the fluctuations of Urmia Lake surface area، multi temporal Land sat Images، ETM، TM sensors، over a 23-year period، 1989 to 2011، were used. In the present study، the coastlines extraction for each year was done in two major steps using the ERADS software & ARC GIS. Firstly، geometric and radiometric corrections as well as different filters on the selected images were applied to make the spectral difference of objects more clear. Secondly، supervised classification method has been used to extract coastlines. To use the supervised classification، the preparation of the training area from the lake surface has been carried out. The reflection values in these areas have been generalized to the entire lake surface using the software and thus، the border between the lake and surrounding areas has been set precisely. Finally، through the algorithm for conversion of two vectors، the coastline limits have been drawn for different years. To carry out the analysis of images the ARC GIS software has been used. Satellite altimeter data measured the lake’s level in 1989 to be at its highest level of any time in the past 30 years. This is in agreement with Hassanzadeh and others، 2011، who state a measured water level of roughly 1 278 m above sea level for the same time. Both measures show a steady decline from that year forward with the most recent satellite altimeter data indicating a drop of approximately 7/40 meters between 1989 and 2011. Because Lake Urmia is a terminal lake with no significant water outflow the only way water leaves the lake is by evaporation. Therefore، if the lake declines it is either by increased evaporation or a decrease in water coming into the system. The Zarrineh Rood River is the largest of the thirteen main rivers discharging into Lake Urmia which are the source of the majority of the Lake’s water budget. Additional input comes from rainfall directly over the lake، floodwater from the immediate watershed and a very small fraction from groundwater flow. The main objective of this study was to assess lake water levels fluctuation using satellite images and geographic information system. To achieve this goal along with field observations and the satellite images of Land sat Multi-spectral images of the years، 2011-1989، sensors، TM، ETM +،. were used and processed. Based on the results achieved during the 23-year-old when the final models، an indication average height Lake water level to the level of 7/40 meter and the decrease in 3588 square kilometers of surface area of Lake water and land turned into the arid soil and sediment salts salt in the last few decades. Most changes due to water loss height، especially in the South East and the east coast of the lake is visible. The rise of water level fluctuations during the study period was significantly accelerated change and backward along the coastal lines 1 to 8/5 km coastline is.

Landslides are amongst the most damaging geologic hazards in the world. They pose a threat to the safety of humankind lives as Well as the environment, resources and property. Compared with other natural hazards such as volcanic eruptions and floods, landslides cause considerable damage to human beings and massive economic losses (Guzzetti, 2005). According to preliminary estimates, about 500 billion riyals annual are caused economic damage in Iran by landslide occurrence (Hosseinzadeh et al., 1388:27). Much literature available on landslide hazard assessment methodologies broadly falls into three main Approach groups: qualitative, quantitative and artificial intelligence (AI) approaches. in general, a qualitative approach is based on the subjective judgment of an Expert or a group of experts whereas the quantitative approach is based on mathematically rigorous objective Methodologies. Artificial Intelligence (AI) techniques can make use of heuristic knowledge or pattern matching technique as opposed to solving a set of mathematical equations. The AI broadly covers Artificial Neural Networks (ANN), Expert system, and other heuristic knowledge-based or rules-based techniques. (Neaupane and Piantanakulchai 2006:281). For the Landslide Susceptibility Mapping can be used a variety of models, such as logistic regression, Analytical Hierarchy Process (AHP), Analytic Network process (ANP), artificial neural network, the bivariate statistical models, LNRF, fuzzy logic models and etc. Usually choose the most appropriate approach and model is done based on the data type, the scale of the study area, the scale of analysis and Knowledge of researcher. Study area: In this study siyahrood catchment has Zonation for landslide susceptibility by using weights of evidence models (Baye's theorem). The basin is located in the province of Gilan. The catchment area is 437 km and is sub-basins of the Sefidrood River. The weight of evidence (WofE) method (Bonham-Carteretal.,1989) has been used to evaluate shallow-landslide susceptibility and has been tested as a useful spatial data model for various applications including mass-movement studies, mineral research, and groundwater spring mapping (Mark and Ellen, 995; Poli and Sterlacchini,2007; Barbieri and Cambuli, 2009).. It takes into account the relationships existing amongst the occurrence of a supporting evidence (shallow landslides in this study) and the distribution of causal factors (shallow-landslide predisposing factors in this study) The WofE is a statistical method based on the Baye's theorem (Denison et al., 2002). This methods first applied to mineral exploration in1988 (Bonham-Carter et al., 1988) and Subsequently, Van Western (2002) applied the method for Landslide susceptibility assessment. Bayes’ theorem can be written as: Equation (1) P(s│B_i)= (P(B_i│s)×P(s))/(P(B_i)) Where P (Bi | s) is the conditional probability to have Bi given s, P (s) is the prior probability to find s within the study area (AS) and P (Bi) is the prior probability to find the class Bi within the study area AS. In this study landslide susceptibility zonation has been done using several natural and anthropogenic parameters Such as (lithology, distance from fault, distance from river, rainfall, land slope, aspect, land use, vegetation density (NDVI) and sediment transport index (STI) stream power index (SPI) and topographic wetness index (TWI)). After the Weights classes were obtained using the model for each parameter, Weights was applied to each class in the Arc map software and eventually with overlay parameters was obtained landslide susceptibility maps. The final Maps was classified In 5 susceptibility class using the method of natural breaks (very low susceptibility, low susceptibility, moderate susceptibility, high susceptibility and high susceptibility). According to the results of the model and the map developed in the lithology layer, Most of the weight is allocated to Class B (old alluvial terraces and High alluvial fans). Moderate range among the different classes of land use and north and northwest directions in the aspect parameter Have the greatest impact on landslide occurrence. As well as slope of 20-10 degrees and 10-5 degrees, respectively and in the layer distance from the river, 100 meters from the river have the greatest impact in landslide occurrence. Assessment models with using landslides occurred in the area show that with increasing risk class, landslide density in the class increases And 59 % of landslide, has occurred in very high susceptibility class. While the area of this class compared to total area of the region is only 10.5 percent. Although Classes with very low susceptibility, low and moderate susceptibility are included approximately 71 percent Area of a Region, But only a small portion of the landslides occurred (16.7%) in these classes While the roughly 83. 3 percent of landslides occurred in the area are located in the fourth and fifth class (high and very high susceptibility). Due to this can be said that the model has a good functionality in the area terms of the prediction of landslides.

Biodegradable elastomeric materials such as poly glycerol sebacate (PGS) have gained much current attention in the field of soft tissue engineering. The present study reports the synthesis of PGS with molar ratios of 1:1, 2:3, and 3:2 of glycerol and sebacic acid via polycondensation reaction and tests the effect of PGS on human corneal epithelial (HCE) cells viability in vitro.

PGS films were prepared by the casting method. We tried to fabricate PGS with different compositions and various properties as being a viable alternative to the corneal stroma in cornea tissue engineering. The chemical properties of the prepared polymer were investigated by means of attenuated total reflectance – Fourier transform infrared spectroscopy (ATR‑FTIR) analysis and the in vitro cytotoxicity was investigated by the Alamarblue method.

The functional groups observed in the PGS FTIR spectrums of PGS with various molar ratios were the same. However, the main difference was the time of completing the cross‑linking reaction. The PGS prepared by 2:3 ratio as a molar ratio had the fastest and the 3:2 ratio had the lowest cross‑linking rate because of the higher amount of sebacic acid. Results of the Alamarblue cytotoxicity test assay showed no deleterious effect on HCE cell viability and proliferation.

PGS is a potentially good candidate material for corneal tissue engineering because of its lack of in vitro HCE cell toxicity.

In this study, WC–20 wt.% equiatomic (Fe,Co) powder mixture was milled in a planetary ball mill. The effects of different milling time (15 min, 5h, 10h, and 25 h) and sintering temperatures on the microstructure and mechanical properties of this equi-Fe substituted cermet were investigated. The structural evolution and the crystallite size changes of the powders during milling were monitored by X-ray diffraction (XRD). Microstructure developments of the samples were examined using scanning electron microscope (SEM). The results showed that the crystalline size of WC and internal strain were 22 nm and about 1.1 % after 25 hours of milling, respectively. The hardness and the relative density of the WC-20wt.% (Fe,Co) composites consolidated by conventional sintering at different temperatures, ranging from 1150 to 1450 ˚C in hundreds, were investigated. The optimized sintering temperature was measured at 1350°C. At a constant sintering temperature, 1350°C, the highest relative density of 98.2% and hardness of 1281 (HV30) were obtained for the milling time of 25h.

The aim of this study was to evaluate the interaction of bioactive and biodegradable poly (lactide-co-glycolide)/bioactive glass/hydroxyapatite (PBGHA) and poly (lactide-co-glycolide)/bioactive glass (PBG) nanocomposite coatings with bone. Sol-gel derived 58S bioactive glass nanoparticles, 50/50 wt% poly (lactic acid)/poly (glycolic acid) and hydroxyapatite nanoparticles were used to prepare the coatings. The nanocomposite coatings were characterized by scanning electron microscopy, X-ray diffraction and atomic force microscopy. Mechanical stability of the prepared nanocomposite coatings was studied during intramedullary implantation of coated Kirschner wires (K-wires) into rabbit tibia. Titanium mini-screws coated with nanocomposite coatings and without coating were implanted intramedullary in rabbit tibia. Bone tissue interaction with the prepared nanocomposite coatings was evaluated 30 and 60 days after surgery. The non-parametric paired Friedman and Kruskal-Wallis tests were used to compare the samples. For all tests, the level of signifi cance was P < 0.05. The results showed that nanocomposite coatings remained stable on the K-wires with a minimum of 96% of the original coating mass. Tissue around the coated implants showed no adverse reactions to the coatings. Woven and trabecular bone formation were observed around the coated samples with a minimum infl ammatory reaction. PBG nanocomposite coating induced more rapid bone healing than PBGHA nanocomposite coating and titanium without coating (P < 0.05). It was concluded that PBG nanocomposite coating provides an ideal surface for bone formation and it could be used as a candidate for coating dental and orthopedic implants.

Osteoarthritis is a degenerative disease caused by damage or trauma to articular cartilage, leading to pain, brittleness, limitation of joint motions and swelling of the tissue. Cartilage damage is common in older people and also athletes. Chondrocytes dedifferentiate in monolayer culture. Tissue engineering involves the use of scaffold to maintain the differentiation of the cells. In this study, maintaining chondrogenic differentiation of the chondrocytes within the pure silk fibroin (SF) and silk fibroin- chondroitin sulfate- alginate (SF-CHS-SA) was compared. Pure SF and SF-CHS-SA scaffolds were prepared through lyophilization. The microstructures of the scaffolds were studied by scanning electron microscopy (SEM). Chondrocytes were isolated from the articular cartilage tissue of rabbit and were cultured within the prepared scaffolds for 14 days. The percentage of chondrocytes viability was measured using 3-(5,4-dimethythiazol-2-yl)-5,2-diphenyltetrazolium bromide (MTT) assay, using extract of the scaffolds. Glycosaminoglycan (GAG) secretion and gene expression of collagen II were studied using alcian blue staining and real time polymerase chain reaction (real time-PCR), respectively. SEM showed that the composite scaffold had higher interconnected pores and pure SF scaffold had mainly closed pores. Results of the MTT assay confirmed no cytotoxicity of the prepared scaffolds. GAG secretion and collagen II expression were significantly higher in the SF-CHS-SA scaffold than the pure SF scaffold (P < 0.05). The SF-CHS-SA scaffold is a much more suitable substrate for maintaining differentiation of the chondrocytes than pure SF scaffold or monolayer culture of chondrocytes.

The aim of the present work is to study the effects of the nanostructured WC-20 wt. % (Fe,Co) with different ratios of iron to cobalt on the microstructure and hardness of sintered samples. Furthermore, a sample with a cobalt binder under the same condition was produced for the comparison purposes. The nanocomposite development, after different milling times, has been monitored by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). A homogenous distribution of nanostructured WC (crystallite size less than 30 nm) in the binder matrix was formed after 25 h milling. The hardness and the relative density of the WC-20wt. % (Fe,Co) composites consolidated by conventional sintering at 1350˚C were investigated. In sintered samples after 25 h milling, tungsten carbide grains have a uniform distribution with a lower grain size. Densification and hardness improved after 25 h milling and reached optimum levels for the 25 h milled powders with equal ratio of iron to cobalt.

In gravity casting of aluminum alloys, turbulent mold filling, reactions between the molten metal and molding materials, melt cooling rate and fluidity as well as inadequate feeding to compensate the solidification shrinkage cause different types of defects. Volumetric defects are among the most important problems in the casting processes and include gas and shrinkage defects which are formed during solidification of the melt. These defects strongly reduce the quality of thin wall castings and have adverse effects on their mechanical properties. In this study, the influence of using nano-ceramics mold coating on sand molds on these defects was investigated and the defects formed in thin samples cast using nano-ceramic mold coating, micro-ceramic mold coating, graphite mold coating and sand mold without coating were compared using x-ray radiography method. The results could lead to production of higher quality AL4-1 alloy components using nano-ceramic coatings.

This research aims at studying and understanding the full capabilities of West Azerbaijan province for sunflower cultivation. Geographic information system (GIS) was used to carry out the research. Climate data elements such as the minimum temperature during the growing season (May to September)، the rainfall during the growing period، the relative humidity during growth of sunflower، were prepared in 9 stations in the region between the years (1387-1373). Slope، soil and elevation data were included to determine and identify the appropriate area of study in the range of sunflower cultivation. Using vegetative needs (favorable climatic conditions) of the crop، the production of information and data rate of each series were classified. In order to investigate the influence of each element in the earth''s climate and physical factors affecting agro-climatic planting of sunflower، the data on temperature، precipitation and relative humidity were combined and then all data elements in the earth''s climate and physical factors together were then integrated. The final map of the land capability for planting of sunflower was produced. Finally، the AHP model، and overlapped data in both weighted area of Zone 2، were used. Sunflower planting area in the north east and eastern parts of the study area (the city of Khoy، Qara Zyaaldyn، Poldasht and Shoot) was specified. The areas suitable for cultivation in both models were chosen to be the city of Qara Zyaaldyn and Poldasht.

The most important limitation of glass ionomer cements (GICs) is the weak mechanical properties. Our previous research showed that higher mechanical properties could be achieved by addition of forsterite (Mg2SiO4) nanoparticles to ceramic part of GIC. The objective of the present study was to fabricate a glass ionomer- Mg2SiO4 nanocomposite and to evaluate the effect of addition of Mg2SiO4 nanoparticles on bioactivity and fluoride release behavior of prepared nanocomposite. Forsterite nanoparticles were made by sol-gel process. X-ray diffraction (XRD) technique was used in order to phase structure characterization and determination of grain size of Mg2SiO4 nanopowder. Nanocomposite was fabricated via adding 3wt.% of Mg2SiO4 nanoparticles to ceramic part of commercial GIC (Fuji II GC). Fluoride ion release and bioactivity of nanocomposite were measured using the artificial saliva and simulated body fluid (SBF), respectively. Bioactivity of specimens was investigated by Fourier transitioned-infrared spectroscopy (FTIR), scanning electronmicroscopy (SEM), Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES) and registration of the changes in pH of soaking solution at the soaking period. Statistical analysis was carried out by one Way analysis of variance and differences were considered significant if P < 0.05. The results of XRD analysis confirmed that nanocrystalline and pure Mg2SiO4 powder was obtained. Fluoride ion release evaluation showed that the values of released fluoride ions from nanocomposite are somewhat less than Fuji II GC. SEM images, pH changes of the SBF and results of the ICP-OES and FTIR tests confirmed the bioactivity of the nanocomposite. Statistical analysis showed that the differences between the results of all groups were significant (P < 0.05). Glass ionomer- Mg2SiO4 nanocomposite could be a good candidate for dentistry and orthopedic applications, through of desirable fluoride ion release and bioactivity.

Cities have been developing since the Industrial Revolution. The growth of cities has many consequences on the environment. As a result of the increase in adverse consequences of the urban growth، United Nations considered the necessity for sustainable development issues in cities. The first step in this procedure is some methods for measurement of the sustainable development by Reliable indicators. Ecological footprint is one of these methods that have been used for measuring urban sustainability in the Cities like London، Santiago، and Liverpool. We have used this method to measure urban sustainability in Rasht County، Iran. The results indicate that the ecological footprint is equivalent to 1. 797 per capita in Rasht. Also biological capacity (biocapacity) in this city is equal to 0. 414 hectar per capita. Therefore، we conclude that Rasht is not sustainable in terms of ecological footprint index. Cities have been developing since the Industrial Revolution with many consequences on the environment. An increase in deleterious effects of urban growth caused the United Nations to pay attention to sustainable development in cities. As the first step in this procedure it is required to measure the sustainable development by reliable indicators. Sustainable development can be measured by determining Ecological Footprint as one of the indicators. This is a measure of the amount of biologically productive land and water required to support the demands of a population or productive activity. The first Ecological Footprints have been calculated using a component based approach. This has evolved into a more comprehensive and robust approach، compound Footprinting، now used for national Footprint accounting. The component-based approach sums the Ecological Footprint of all relevant components of a population in resource consumption and waste production. This is، first، by identifying all of the individual goods and services and the amounts thereof a given population consumes، and second، by assessing the Ecological Footprint of each component using life-cycle data that track the resource requirements of a given product from resource extraction to waste disposal. Ecological footprint method has already been used for measuring urban sustainability in the Cities like London، Santiago، and Liverpool. We have used this method for measuring urban sustainability in Rasht County، Iran. The Ecological Footprint utilize the yields of primary products (from cropland، forest، grazing and fisheries) to calculate the area necessary to support a given activity. Biocapacity is measured by calculating the amount of biologically productive area of land and sea available to provide the resources a population consumes and to absorb its wastes، given current technology and management practices. Countries differ in the productivity of their ecosystems، and this is reflected in corresponding accounts. Ecological Footprint accounts allow governments to track a city or region’s demand on natural capital، and to compare this demand with the amount of natural capital actually available. The accounts also give governments the ability to answer more specific questions about the distribution of these demands within their economy. In other words، it gives them information about their resource metabolism. They also help assess the ecological capacity embodied in the imports upon which a region is dependent. This can shed light on the region’s constraints or future liabilities in comparison with other regions of the world، and identify opportunities to defend or improve the local quality of life. Footprint accounts help governments become more specific about sustainability in a number of ways. The accounts provide a common language and a clearly defined methodology that can be used to support staff training and to communicate about sustainability issues with other levels of government or with the public. Footprint accounts add value to existing data sets on production، trade and environmental performance by providing a comprehensive way to interpret them. For instance، the accounts can help guide “environmental management systems” by offering a framework for gathering and organizing data، setting targets and tracking progress. The accounts can also serve as environmental reporting requirements، and inform strategic decision-making for regional economic development. The global effort for sustainability will be won، or lost، in the world’s cities، where urban design may influence over 70 percent of people’s Ecological Footprint. High-Footprint cities can reduce this demand on nature greatly with existing technology. Many of these savings also cut costs and make cities more livable. Since urban infrastructure is long-lasting and influences resource needs for decades to come، infrastructure decisions make or break a city’s future. Which cities are building future resource traps? Which ones are building opportunities for resource efficient and more competitive lifestyles? Without regional resource accounting، governments can easily overlook or fail to realize the extent of these kinds of opportunities and threats. The Ecological Footprint، a comprehensive، science-based resource accounting system that compares people’s use of nature with nature’s ability to regenerate، helps eliminate this blind spot. We have used the Ecological footprint method for testing the research hypotheses. Ecological footprint is a measure of human demand on the Earth''s ecosystems. It is a standardized measure of demand for natural capital that may be contrasted with the planet''s ecological capacity for regeneration. It represents the amount of biologically productive land and sea area necessary to supply the resources a human population consumes، and to assimilate associated waste. Using this assessment، it is possible to estimate how much of the Earth it would take to support humanity if everybody followed a given lifestyle. The results show that the ecological footprint is equivalent to 1. 797 per capita in Rasht. Also biological capacity (biocapacity) in this city is also equal to 0. 414 hectar per capita. In the study area ecological Footprint is much more than the biological capacity. This means the instability in ecological system. The Ecological Footprint in consumption for the study area is lower than other counties in Iran. According to the results of the study، we conclude that Rasht is not sustainable in terms of ecological footprint index. Although the county is ecologically instable، but the Ecological Footprint in Rasht County is lower than that in the Iran and in the world. The instability may be resulted from excessive use of natural resources and also tourism activities. It can be recommended to have optimized use of natural resources، suitable planning for tourism، and education of the public for sound consumption of resources.

The interim restorative materials should have certain mechanical properties to withstand in oral cavity. The aim of this study was to evaluate the hardness and wear resistance ofinterim restorative materials. Fifteen identical rectangular shape specimens with dimensions of 2 mm × 10 mm × 30 mm were made from 7 interim materials (TempSpan, Protemp 3 Garant, Revotek, Unifast LC, Tempron, Duralay, and Acropars). The Vickers hardness and abrasive wear ofspecimens were tested in dry conditions and after 1 week storage in artificial saliva. The depth ofwear was measured using surface roughness inspection device. Data were subjected to Kruskal–Wallis and Mann–Whitney tests. The Pearson correlation coefficient was used to determine therelationship between hardness and wear (á =0.05). TempSpan had the highest hardness. The wear resistance of TempSpan (in dry condition) andRevotek (after conditioning in artificial saliva) was significantly higher (P < 0.05). There was no statisticallysignificant correlation between degree of wear and hardness of the materials (P = 0.281, r = –0.31). Hardness and wear resistance of interim resins are material related rather than category specified.

Many efforts have been made to improve Ni-Ti alloy for endodontic use and it has been shown that surface properties and thus cutting efficiency of the rotary files can be improved by processes such as electro-polishing، ion implantation and surface coating. The aim of this study was to evaluate the effect of cryogenic treatment on cutting efficiency of Ni-Ti rotary files. In this in vitro study، 60 Ni-Ti rotary instruments (Hero 642، #25، 0. 04 taper) were selected and divided into 3 groups of 20. In group I no treatment was used. In group II the instruments were subjected to a deep cryogenic treatment in liquid nitrogen pool (-196°C) for 24 hours and after treatment were immediately tested for cutting efficiency. In group III after cryogenic treatment the temperature of the samples was raised slowly to room temperature for 24 hours. A new piece of test equipment was designed and used. The instruments were attached to the testing machine and rotated in Plexiglas samples for 10 seconds in a working length of 16 mm. The depth of grooves and weight loss of Plexiglas were measured after instrumentation. One-way and two-way ANOVA were used to compare the means of cutting efficacy between the three groups at 95% confidence interval. The instruments which were immediately tested for cutting efficiency had significantly more weight loss and deeper grooves (pweight < 0. 001; pgroove = 0. 022)، indicating better cutting efficiency. However، there was no significant differences between group I and group III in cutting efficacy (p weight = 0. 23; p groove = 0. 61). The results of this study showed that the surface properties of Ni-Ti alloy could be improved by the cryogenic treatment for a limited period of time after treatment، increasing the cutting efficiency of Ni-Ti rotary instruments.

The concept of environmental hazards on rural planning is considered necessary andimportant that it be comprehensive and constructive cooperation of the villagers in themodulation of plans and programs of the risks of conflict efficient management this sphereprovide. This article aims to assess natural hazards - human capabilities and limitations of theassay, resulting in Gonbarf village life and the village in order to develop the best strategiesand environmental planning. To achieve this purpose, the method of SWOT-AHP hybridmodel that utilizes the SWOT technique, attempt to identify the strengths and weaknesses(internal factors) and opportunities and threats (external factors), and the use of the AHPmodel and Likert preference polls and Rankings internal and external environmental factorsand determine the final value of internal and external factors and adopt the best strategy and astrategy for prioritization approaches in terms of SO, WO, ST, WT. The results of the modelcombination strategy of SWOT-AHP analysis tables indicate the superiority of naturalfeatures - human hazards, so that the final result of the evaluation and assessment of internaland external factors indicate that the strength (with a total value of final 0.233) andopportunities facing the region (the sum of the final value of 0.324) weaknesses (the sum ofthe final value 0.230) and the threats surrounding it (with a total end value of 0.213) is higherand thus the overall strategies of the invasive strategy should be formulated in such a wayenvironmental opportunities and can be used strengths