a. r. ghasemi

Laser cladding technology , creates the ability to produce, repair and optimize parts with high accuracy and complexity. Laser cladding exhibits highly complex heat transfer and thermoelastic-plastic-flow with multi-physics field coupling changes, which are accompanied by such physical phenomena as melting, solidification and phase transitions in the metal and non-metal powders. This process involves high thermal gradients and heating and cooling rates that cause residual stresses, torsion, and distortion. The temperature rates and flow fields in the molten pool affect convection, heat transfer, mass transfer, and solidification, which ultimately affect the quality of the cladding layer. The quality and properties of the cladding can be determined by many factors such as cladding geometry, microstructures, dilution ratio, defects, distortion, surface smoothness and metallurgical changes in the substrate and process efficiency. These factors, regardless of their degree of importance, are affected by the parameters of the cladding process and the physical phenomena that occur during the process. In this research, a landscape review on the process of laser cladding, type and methods, characteristics of process and effective parameters on process are studied and presented.

The discrete element method (DEM) has been used as a popular simulation method in order to verify the designs by visualizing how materials flow through complex equipment geometries.  Although DEM simulation is a powerful design tool, finding a DEM model that includes all real material properties is not computationally feasible.  In order to obtain more realistic results, particle energy loss due to rolling friction has been highlighted by many researchers using various models to implement a reverse torque.  On account of the complexity of the problem, there is no unique model for all applications (i.e. dynamic and pseudo-static regimes).  In this research work, an in-house developed DEM software (KMPCDEM©) was used to assess the robustness of three models by comparing the repose angle obtained through the draw down test. The elastic–plastic spring dashpot model was then modified based on considering the individual parameters instead of the relative parameters of two contact entities.  The results showed that the modified model could produce a higher repose angle.  The modified model was used for the calibration of DEM input parameters in the simulation of repose angle of iron ore pellets in a laboratory setup of the draw down test.  Comparison of the calibrated DEM simulation (using 0.0007 and 0.75 for the rolling and sliding friction coefficients, respectively) with the laboratory results showed a good agreement between the predicted and measured angle of repose.  The non-calibrated DEM simulations are susceptible to error, and therefore, it is strongly recommended to use the laboratory experiments to characterize the materials before using the DEM simulation as a design tool of industrial equipment.

Supply chains have grown rapidly in recent years and only focusing on economic performance for the optimization of costs or Investment return cannot lead to the development or sustainability in the supply chain. For this purpose, the concepts of green supply chain management and sustainable supply chain management emerged to highlight the importance of social and environmental concerns with economic factors on supply chain planning. This study to combine qualitative research conducted in the field of sustainable supply chain and examines 31 papers by using the meta-synthesis method. In the present study were identified 287 codes in Maxqda software. Among the extracted codes, Recovery and recycling of the product (29 hint), Image and reputation of the company (24 hint), Performance evaluation and supplier selection (22 hint), were as the most important detected codes. Including innovation of research to identify indicators of sustainable supply chain, using meta-synthesis qualitative research methods and Maxqda software in the field of sustainable supply chain. Lack of access to some articles full-text search is also one of the main problems of the research. Other obstacles in this research the lack of Persian source in the field of sustainable supply chain. Other obstacles in this research the lack of Persian source in the field of sustainable supply chain.

In this research, we study the effect of the composite high speed planning vessel hull stroke on water surface. To improve the hull ofhigh speed planning vessel against the impact of water, an appropriate reason was offered and this reason was tested for a real available vessel and the consequent results were presented. Finally, the thickness of the hull of the tested vessel was decreased in the composite sandwich panel core and by reinforcing the hull structure, the weight of the vessel was decreased in 17.6% percent. The acquired results from the direct limited element on improved vessel hull, will meet the limitations of DNV standards. At the end, the result of optimization was similar confidence coefficient (according to DNV standards) and steady strain distribution for different parts of the vessel hull.

As previous studies on the association between obesity and cardiovascular (CVD) risk factors have been made in limited populations, this study was performed to determine the association in 3 cities in the central parts of Iran. In this cross-sectional study, data collected in the1st phase of the Isfahan Healthy Heart Program (IHHP), involving 12514 subjects ≥19 years old, conducted during 2000-2001, in Isfahan and the Central Provinces of Iran, were analyzed. Fasting blood sugar (FBS), 2-hour post-load plasma glucose (2hpp), serum lipid profile, anthropometric parameters and blood pressure were determined by standard methods. FBS, 2hpp, serum lipids fractions (except for HDL-C) and blood pressure had significant positive relations with body mass index (BMI) and waist circumference (WC) (all p-values<0.001). As compared to the 1st quartile of WC, odds ratios (OR; 95%CI) of hypertension, diabetes and dyslipidemia in the 4th quartile were 2.8 (1.2-3.3), 3 (1.6-4.3) and 2.4 (1.9-3.1) in men and 2.5 (1.8-3.4), 2.7 (1.3-3.8) and 2.5 (2-3.2) in women, respectively. Also, ORs (95%CI) of hypertension, diabetes and dyslipidemic in 4th quartile of BMI, as compared to the 1st, were 1.6 (1.2-2), 2.8 (1.7-3.9) and 3 (2.4-3.8) in men and 1.9 (1.4-2.4), 2.6 (1.4-3.7) and1.6 (1.2-2) in women, respectively. ORs of these risk facrors increased with increasing WC and BMI. Therefore, it is concluded that both obesity indicators increase the chance of CVD risk factors.

The influence of the Sea Surface Temperatures (SSTs) on the seasonal precipitation over northern and southwestern parts of Iran was investigated. The warm, cold and base phases of the SSTs were defined and the median of precipitation during each of these phases (Rw, Rc and Rb, respectively) was determined. The magnitude of Rw/Rb, Rc/Rb and Rc/Rw were used as criteria for the assessment of the effects of the alternation of SST phases on seasonal precipitation. The results indicate that in association with cold SST phase, winter rainfall is above median over western and central parts of the coastal region, central and southern parts of Fars Province and all the stations studied in Khozestan Province. On the other hand, the prevalence of warm SST phase has caused about 20% decrease in winter precipitation over the Caspian Sea coastal area and northern parts of both Fars and Khozestan provinces. In association with warm SST phase in winter, precipitation during the following spring was found to be above normal for all the stations studied in the coastal region of the Caspian Sea. The highest sensitivity levels were found in Bandar- Anzali and Astara for which spring precipitation has increased by 80% due to the dominance of warm winter phase. However, the occurrence of boreal cold SST events causes shortage of precipitation in the eastern parts of the coastal areas along the Caspian Sea. A Possible Physical mechanisem justifying the influence of the Caspian Sea SST on the Precipitation variability was introduced. According to this mechanisem, temporal and spatial variability of the Siberian High is forced by the fluctuations in these SSTs.

The present study evaluates the influence of the El Ninio Southern Oscillation (ENSO) phenomenon on the cold season precipitation over Isfahan, Fars, Khuzestan, Chaharmahal-Bakhtyari, Bushehr and Kohgiluyeh-Boyerahmad provinces. The results indicate that the occurrence of La Nina events caused a 20% to 50% reduction in precipitation over Bushehr, Chaharmahal-Bakhtyari and southern Fars. The cold event did not change the total precipitation over the other parts of the region. In contrast to La Nina episodes, the occurrence of El Ninio events caused a 20% to 70% increase in rainfall in most of the study area. While the most highly wet conditions are related to the El Ninio events, the occurrence probability of the severe droughts has found to be low during such events. In association with La Nina events, the occurrence probability of severe drought was found to be low. Only in Khuzestan and southern parts of the Fars Provinces, this probability has increased to about 0.5.