فهرست مطالب mohammadamin jafari

The Mayamey area (northeast of Shahrud), which forms a part of the Joghatay-Sabzevar zone, hosted Padiform chromite deposits with Harzburgite (ophiolitic) host rock, in which serpentine alteration is strongly spread. In this study, in order to identify the promising areas of chromite mineralization, host rock evidence maps (lithological), serpentine alteration resulting from remote sensing data processing, fault density, geophysics-magnetism, and geochemical of Cr have been used. Then, using the Fuzzy-Gamma function and the gamma value of 0.85, the evidence maps were weighted and fuzzified between 0 and 1 and integrated with each other in the GIS environment. According to the final map of chromite potential, the access roads and geological conditions of 11 areas were determined as exploration targets. Based on the searches, it was found that out of the 11 designated areas, there were three active mines, six promising areas, and two areas without chromite mineralization. The results of XRF analysis of two control samples S4 and S5 showed that the grade of chromite in these areas is 40.02% and 52.44%, respectively, which shows the economic grade of chromite, high accuracy, and the correct method of combining the selected observer maps in this is study. Also, the geochemical study showed that the amounts of MgO, Al2O3, TiO2, Fe2O3, and Cr2O3 are consistent with the accumulation type chromites and the chromites of the study area are rich in Cr and to some extent Fe and poor in Al.

The structure of a satellite, during its operational life, should be tolerated all applied mechanical loads which the most important of them is vibration loads during the launch. To verification of design process, finite element analysis and vibration tests should be performed on the structure of satellite according to the ECSS standard. In this paper, while simultaneously examining the optimal design process for a satellite structure with an increase in the strength to mass ratio, the required finite element analyzes along with the mechanical tests of the structure of a telecommunication satellite, including random vibrations, sinusoidal vibrations, shock and quasi-static, are fully presented. The results showed that by employing the cross section design for the satellite structure, the natural frequency of the satellite in the longitudinal direction have increased appreciably, which increases the strength of the satellite in the longitudinal direction. The experimental results proved that the designed structure meets the frequency requirements of the launcher while tolerate the mechanical loads during launch. Also, the experimental results were in good agreement with the numerical results, including the modal analysis, random and sine vibration. Therefore, design processes of the satellite structure were verified by experimental tests.

The Malayer-Esfahan metallogenic belt hosts large deposits of Zn-Pb with sedimentary host rocks. In addition to Zn-Pb mineralization, Cu, Cr, Au, Fe, Mn, W have been mineralized in this area with different host rocks. In the present study, using airborne magnetic data, promising mineral areas in Malayer-Esfahan metallogenic zone have been introduced. Using reduction to pole (RTP) filters, signal analytical and vertical derivative were processed and airborne magnetic data were interpreted. The map derived from the vertical derivative is considered as the final map to identify anomalies resulting from airborne magnetic data. Due to the sedimentary nature of the Malayer-Esfahan area and the fact that the minerals in the rocks of this area usually have low magnetic properties, the anomalies obtained from the airborne magnetic data showed a relative overlap with some the Zn-Pb deposits in the area; According to this case, the anomalies obtained in this study can be used to identify iron reserves other than Zn-Pb in this area. Anomalies resulting from the vertical derivative filter with iron deposits more than Zn-Pb deposits such as Shams-Abad and Akhtarchi Fe deposits, Astaneh and Muteh Au deposits, Rousht W deposit, Ghaleh-Arab Cu deposit, Ahangaran Zn-Pb deposits, Saleh-Payghambar, Ab-Bagh, Dardahaneh, Khan-Abad, Lakan and etc show overlap. In general, the results of this study showed that in the northwestern, central, and southeastern parts of the Malayer-Esfahan metallogenic zone, there are areas as new and hidden anomalies that can be used for sampling of promising mineral areas by sampling and spectroscopy.

Dark circles and wrinkles under the eyes are common cosmetic problems, caused by various conditions, especially aging and overproduction of melanin in the epidermis or dermis of the skin. In addition to the application of topical lightening agents, different types of lasers, especially the Q-Switched ND:YAG laser, has been used for the treatment of cutaneous hyperpigmentation. Because of a high prevalence of idiopathic eye dark circles (EDCs) or periorbital melanosis and a poor response to available therapies, we decided to evaluate the efficacy and safety of the Fractional QS 1064 nm ND:YAG Laser through a before-after trial.

18-65-year-old patients with skin Fitzpatrick phototype of I-V and without any usage of a topical or systemic therapeutic regimen (2-4 weeks before the trial) were enrolled in the study. Each patient was treated with 6 sessions of the Fractional QS 1064 nm ND:YAG Laser at 2-week intervals and assessed for response and possible side effects or recurrences through 4 outcome measures, including Visoface-based color and erythema, melanin index and lightness (Before the fourth and sixth sessions of the therapy; also 1 week and 3 months after finishing the trial).

The changes in Visoface-based color and erythema, the melanin pigment amount by the Mexameter (melanin index) and the degree of lightness by the Colorimeter of patients after 6 months of intervention were statistically significant (P<0.001).

The fractional QS 1,064 nm ND: YAG Laser is an effective and safe therapy in EDCs since objective outcomes like the reduction of the melanin index and improving lightness and subjective ones like the reduction of darkness and erythema were confirmed.

Composite hemangioendothelioma (CHE) is a rare and little-known condition with combined benign, intermediate, and malignant features. In the current study, we describe the case of a young female with the presentations of CHE, representing the second known case in Iran. Also, we have comprehensively reviewed previous case reports of CHE. A 30-year-old female was referred with a reddish hemorrhagic painless mass in the small right finger that appeared within a few days following trauma. The mass was primarily excised but recurred within three weeks; therefore, she underwent thorough clinical, laboratory, and imaging studies. Finally, the lesions were biopsied and diagnosed as CHE. Accordingly, the involved finger was amputated, and the patient underwent chemoradiotherapy. Although CHE is a rare malignant condition worldwide, attention to the clinical presentations of this malignancy can help scientists make better therapeutic approaches leading to the best outcomes.

In the present study, an attempt has been made to identify the seismic risk zoning of Khuzestan province due to its location in the seismic state of Zagros. To achieve the desired goal, geological data, analytical hierarchy process (AHP), and GIS decision support system was used. The information layers used in this study were: digital elevation models (DEM), land slope, faults density, earthquakes density of the last 20 years, the distance of faults (buffer), the distance of earthquakes of the last 20 years (buffer), and interpolation (IDW) layer of earthquakes of the last 20 years’ province. The results of this study that the northeastern and northern parts of Khuzestan province have the highest seismic risk that the cities of Masjed Soleyman, Andika, and Izeh have high earthquake potential, Dezful, Lali, and Gutvand have moderate earthquake potential. A few cities such as Ahvaz, Abadan, and Dasht -e- Azadegan plain have low earthquake potential. The earthquakes of the last 10 years in Khuzestan province also showed good overlap with high-risk points. The reason for the high risk of earthquakes in these areas can be considered as the existence of many faults, many human activities such as dam construction, extraction from groundwater aquifers in areas with active faults, and the release of seismic energy of active faults.

In this research, using fuzzy logic (gamma) methods, analytic hierarchical analysis (AHP), and based on the weighting of exploratory layers by the opinion of geoscientists, modeling of mineral potential for lead and zinc metals in the Khondab sheet. The geochemical layer related to Pb-Zn metals has been prepared using the singularity index (SI) method, which has high accuracy in detecting weak and hidden anomalies. All exploratory layers and substrates including lithology, geochemistry, the density of lead and zinc deposits and mineral signs, the density of faults and silica and carbonate alterations were weighted using the fuzzy logic (gamma) method and ranged from 0 to 1 and fuzzy layers with gamma value (γ) of 0.95 were combined with each other and prepared the potential maps for Pb-Zn metals in the study area. Then, using the AHP method and forming a suitable matrix for the exploratory layers, the layers were weighed and a potential map of the desired metals was obtained. The results showed that the AHP method identified more anomalies compared to the fuzzy logic (gamma) method and the anomalies obtained from this method show more compliance with the Pb-Zn deposits in these regions.

Recessive dystrophic epidermolysis bullosa (RDEB) is an autosomal recessive disorder that affects type VII collagen, one of the main components of the basement membrane. Patients present with non-healing chronic wounds in the body, extremities, and mucosal areas. There are many suggestive medical and surgical treatments, but most are ineffective. In this case, we discuss a new laserassisted surgical protocol for these types of patients. A 54-year-old male patient was suffering from RDEB with large, excruciating, non-healing wounds on his extremities dating ten months, with no reasonable improvement, despite receiving intensive wound care. After ruling out other diagnoses (particularly malignancies), treatment was performed with a fractional Er:YAG laser for a single session. After four weeks of follow-up, the patient showed significant improvement, with no considerable complications reported. Fractional ablative Er:YAG laser could be an effective treatment option in RDEB patients. Clinical trials are required with long-term follow-ups for this novel treatment approach.

Separation of geochemical anomalies from the background has always been a major concern of exploration geochemistry. The search for methods that can make this analysis quantitative and objective aims not only at the reduction of but also at providing an automatic routine in exploration, assisting the interpretation and production of geochemical maps (Nazarpour et al., 2015). The Malayer-Isfahan metallogenic belt with the north-west-south-east trend is the largest and most important Pb-Zn belt of MVT type in Iran (Rajabi et al., 2012). In this study, separation of Pb and Zn geochemical anomalies was performed using the methods named further in the study area.

1. Classical statistics Various statistical methods have been used to process geochemical data in order to determine threshold values. Statistical quantities, such as the mean, standard deviation (SDEV) and percentiles, have been used to define thresholds for separating anomalies form the background. For example, geochemical anomalies have been defined as values greater than a threshold value defined as the 75th or 85th percentile, and Mean+SDEV or Mean+nSDEV (Nazarpour et al., 2015). The boxplot and median+2MAD techniques of the EDA approach have been widely used to separate geochemical anomalies from the background. In exploratory data analysis (EDA) of geochemical exploration data, the median+2MAD value was originally used to identify extreme values and serve as a threshold for further inspection of large data sets (Carranza, 2009). The MAD (is the median of absolute deviations of individual dataset values (Xi) from the median of all dataset values (Tukey, 1977). 2. Multifractal models Fractal and multifractal models have also been applied to separate anomalies from background values. These methods are gradually being adopted as effective and efficient means to analyze spatial structures in metallic geochemical systems (Cheng et al., 1994). The concentration-number (C-N), concentration-area (C-A) multifractal methods have been used for delineation and description of relations among mineralogical, geochemical and geological features based on surface and subsurface data (Nazarpour et al., 2015). Fractal/multi-fractal models consist of frequency distribution and spatial self-similar or self-affine characteristics of geochemical variables. These fractal/multifractal models have been demonstrated to be effective tools for decomposing geological complexes and mixed geochemical populations and to recognize weak geochemical anomalies hidden within strong geochemical background (Cheng et al., 1994).3. Singularity Index (SI) The Singularity technique is another important process for fractal/multifractal modeling of geochemical data (Zuo et al., 2015). This technique is defined as the characterization of the anomalous behavior of singular physical processes that often result in anomalous amounts of energy release or material accumulation within a narrow spatial–temporal interval. The Singularity can be estimated from observed element concentration within small neighborhoods based on the following equation (Cheng, 2007): (1) The Singularity Index is a powerful tool to identify weak anomalies, but it is influenced by the selection of the window size. (Zuo et al., 2015).

In this study, a total of 19946 stream sediment geochemical samples were analyzed using the ICP-MS and XRF methods. In the maps derived from the Singularity Index (SI) the higher accuracy of this method compared to other applied methods was employed. Therefore, the hidden and weak anomalies are better represented, and a better overlap with limestone as the major host rock of Pb and Zn deposits (MVT type) in the study area were observed. A comparison among all of the applied methods indicates that the concentration of Pb and Zn increased toward the and south east and northwest parts, respectively. In these regions there is a high potential for the occurrence of promising mining areas. Moreover, the obtained Pb and Zn anomalies have a good correlation with the exposure of limestone in the study area.

Rapid development of engineering activities expands through a variety of rock engineering processes such as drilling, blasting, mining and mineral processing. These activities require rock dynamic fracture mechanics method to characterize the rock behavior. Dynamic fracture toughness is an important parameter for the analysis of engineering structures under dynamic loading. Several experimental methods are used for determination of dynamic fracture properties of materials. Among them, the Hopkinson pressure bar and the drop weight have been frequently used for rocks. On the other hand, numerical simulations are very useful in dynamic fracture studies. Among vast variety of numerical techniques, the powerful extended finite element method (XFEM) enriches the finite element approximation with appropriate functions extracted from the fracture mechanics solution around a crack-tip. The main advantage of XFEM is its capability in modeling different on a fixed mesh, which can be generated without considering the existence of discontinuities. In this paper, first, the design of a drop weight test setup is presented. Afterwards, the experimental tests on igneous (basalt) and calcareous (limestone) rocks with single-edge-cracked bend specimen are discussed. Then, each experimental test is modeled with the XFEM code. Finally, the obtained experimental and numerical results are compared. The results indicate that the experimentally predicted dynamic fracture toughness has less than 8 percent difference with calculated dynamic fracture toughness from extended finite element method.

This study has been aimed to A Study on the Comparison of Students' Learning Quality before and After Intelligence of Schools from the Viewpoint of Primary Teachers in Yasuj The research methodology was descriptive-survey and statistic populations of the study were considered all primary teachers in Yasouj who has been thought in schools during the 1393- 94 academic year. 140 members of primary teachers selected based on Morgan table, Krejcy and Cochran formula and by using of stratified random sampling, eventually was distributed self-made questionnaire of learning quality among them. It was used Cronbach's alpha in order to determine the questionnaire validity from content validity and also its reliability. The obtained information in this study was analyzed by using descriptive statistics (frequency, compiling table, standard deviation and mean) and also inferential statistics (paired t-test). The results indicated smart schools have positive and significant effects on the all dimensions of learning quality.