This study was done to evaluate the changes in bulk density (Db) of the 0-10 cm surface soil of skid trails in the Hyrcanian hardwood forests, Iran. The treatment involved running a rubber-tired skidder in three skid trails: Flat Skid Trail (STF), Skid Trail with Transversal Slope (STTS), and Skid Trail with Longitudinal Slope (STLS). Pre- and post-skidding activities, soil cores were collected at random points of upslope and downslope tracks of each skid trails to measure soil bulk density and moisture content. In general, mean bulk density of compacted soil in skid trails was significantly greater than that of undisturbed soil. A significant increase (P<0.01) in soil bulk density occurred during first six skidding cycles at the STTS and STLS, when the soil moisture content was about 30% and 35%, respectively. But on STF, the increase in bulk density was greatest during first twelve skidding cycles. Additional cycles, up to 6 (on the STTS and STLS) and 12 (on the STF) cycles, did not cause significant increase in bulk density. The severe soil compaction was concentrated on the STTS.

The results of the dimensional analysis by Buckingham method showed that the discharge coefficient(Cd), function "Ht/P" (represents the total hydraulic head ratio (total hydraulic head to the height of the weir)), "Sf" (represents the form factor of the weir) and "Nnp".Physical and numerical modeling was done in a rectangular flume with the length of 8 meters, width of 0.6 meters and height of 0.6 meters.The results of the study showed that creating an additional cycle has a positive effect on the TRTPIO weir, and it causes the discharge coefficient as well as its hydraulic performance to increase compared to the placement of the nappe breaker.creating an additional cycle and placing the nappe breaker on the labyrinth weir at the same time makes the TPTPIO weir with 4 nappe breakers have a higher discharge coefficient than other models.Quantitative evaluation of the results of this study shows that, for example, in the hydraulic head ratio of 0.24, the discharge coefficient of TRTPIO weir compared to TPTPIO weir, TPTPIO with 4 nappe breakers, TRTPIO with 4 nappe breakers, is 21, 8.5 and 21% have higher discharge coefficient; On the other hand, the Mattos-Villarroel weir has a higher discharge coefficient than the TRTPIO weir by 7.8%.The results of numerical modeling showed that with the increase of hydraulic head, the discharge coefficient decreases.while the increase of hydraulic head in labyrinth weirs causes an increase in the interference of nappe flow, energy loss, local submergence, and finally, a decrease in the hydraulic efficiency of the weir.

In conventional internal combustion engines, about 40% of fuel energy is turned into useful power and the rest is driven by cooling and exhaust system out of the engine. Therefore, there is a ground to recover energy from this wasted energy by fixing an additional cycle inline with the exhaust gas outlet. In this research, a stirling cycle was used for this purpose. Initially, the internal combustion engine was simulated. The engine studied was an EF7-NA spark ignition internal combustion engine and the simulation results were validated by using experimental results. The results showed that the exhaust gas outlet temperature varies from 393 to 848 ° C, according to engine operating conditions. Therefore, by installing a Stirling engine heater inline with the exhaust gases from the EF7 engine, the wasted energy can be turned into useful work. To validate the results of one-dimensional Stirling engine simulation, the experimental results of the Stirling Solo V161 engine were used. After validating the Stirling engine model, the combined cycle was simulated, combining a Stirling engine at working pressure of 50, 60 and 70 bar and EF7 engine at engine speed of 2000 to 4500 rpm. The results showed that at an optimal pressure of 50 barfor the Stirling engine, the EF7 power gain was 12.2% and an average efficiency increase of 5.2%, regardless of the weight of the added stirling engine in the car which considering that, a low impact on the power of the combined cycle is expected.

Gestational trophoblastic neoplasia (GTN) refers to malignant lesions that arise from abnormal proliferation of placental trophoblast. Even in its metastatic forms GTN is curable with a cure rate of 90-100 %. Currently، methotrexate with or without folic acid، andactinomycin D is recommended for low risk GTN. The aim of this study is to compare the efficacy of methotrexate and actinomycin D as the first-line single chemotherapeutic agents for women with low-risk gestational trophoblastic neoplasia (LR-GTN). A total of 30 women with LR-GTN were randomized to receive a weekly pulsed dose of 40 mg/m (2) of methotrexate intramuscularly (n=15) or a pulsed intravenous bolus of 1. 25 mg/m (2) of actinomycin D every 2 weeks (n=15). An additional cycle was administered as consolidation treatment following normalization of the serum level of beta-human chorionic gonadotropin (˂10 IU/L). Complete remission was achieved in 53. 3% of patients in the methotrexate group and 86. 7% in the actinomycin D group (p˂0. 04). The mean number of treatment cycles needed to achieve response was lower in the actinomycin D group (4. 3 vs. 6. 5). The mean duration from beginning of treatment till achieving complete remission was 9. 6 weeks for the Act group and 13 weeks for the MTX group. Actinomycin D may be a better option than methotrexate as a first-line chemotherapy agent for patients with LR-GTN but larger multicenter randomized controlled trials should be conducted to establish the most appropriate regimen for these patients.

In this study, a precise finite element analysis has been carried out on a diesel engine piston, in order to attain its high cycle fatigue (HCF) safety factor and low cycle fatigue (LCF) life. In order to calculate the HCF safety factor, a macro has been developed using ANSYS Parametric Design Language (APDL). The relative stress gradient parameter is used in order to perceive stress concentration and notch effect. In high cycle fatigue assessment, the effect of mean stress is considered using Haigh diagram. Different LCF life assessment methods have been used to investigate LCF life of piston and their results are compared to each other. The diesel engine piston is subjected to non-proportional multiaxial loading. The non-proportional loading leads to an additional cyclic hardening in the material. Critical plane LCF theories are appropriate for consideration of the additional cyclic hardening effect on the LCF life reduction of the piston.

Energy - Utilization Diagrams is a graphic method to describe the exergy losses in industrial processes, i.e., improving the exergy use. We apply the method to a 3MW kalina bottoming Cycle. In the Kalina cycle, thermal energy transforms to mechanical energy and we can change the thermal losses to useful mechanical energy at best efficiency in comparison with another thermal machines. In this cycle against Rankine cycle, the ammonia-water mixture is used as fluid., therefore by suitable setting of this two fluids in various points of the cycle, we could give optimum total efficiency and since we have two type of fluids, should consider additional equipment in this cycle. The Kalina Cycle is being developed as a competitive improvement of the Rankine steam Cycle. By using an ammonia – water mixture as the working fluid and a condensing system based on absorption refrigeration principles the Kalina bottoming Cycle becomes about 10% more efficient than the ordinary Rankine Cycle. The Energy-Utilization Diagram of the kalina Cycle is very tight. From this we see that the Cycle is very well optimized.

Most of mechanical components of automobile engine and structures applied in powerhouses, petrochemical and aviation industries are subjected to different kinds of cyclic loadings, such as low cycle fatigue (LCF) stresses at high temperatures. Thermo-mechanical fatigue is the dominant cause of fracture in these components.Therefore, investigation of different thermo-mechanical fatigue life assessment methods of these components is very necessary. When a component is subjected to high temperature thermal cycles and mechanical strain cycles simultaneously, the thermo-mechanical fatigue process leads to micromechanical damage and final fracture of the component.In this study a precise procedure for the Thermo-mechanical fatigue life assessment of hot diesel engine components is investigated. In high cycle fatigue assessment, the effect of mean stress is considered using Haigh diagram. Different LCF life assessment methods have been used to investigate LCF life and their results are compared to each other. Almost all of the engine components are subjected to proportional or non-proportional multiaxial loadings. The non-proportional loading leads to an additional cyclic hardening in the material. Critical plane LCF theories are appropriate for consideration of the additional cyclic hardening effect on the fatigue life reduction of the component. Effect of high cycle fatigue on low cycle fatigue life reduction is also studied. Finally, the discussed thermo-mechanical fatigue life assessment process is used to estimate thermo-mechanical fatigue life of a diesel engine piston.

This paper considers the problem of stable limit cycles generating in a class of uncertain nonlinear systems which leads to stable oscillations in the system’s output.This is a wanted behavior in many practical engineering problems. For this purpose, first the equation of the desirable limit cycle is achieved according to shape, amplitude and frequency of the required output oscillations. Then, the nonlinear control law is designed such that the phase portrait of the closed-loop system includes this stable limit cycle. The design of controller is based on the Lyapunov stability theorem which is suitable for stability analysis of the positive limit sets (the stable limit cycle is a positive limit set for the nonlinear dynamicl system). The proposed robust controller consists of two parts: nominal control law and additional term which guarantees the robust performance and vanishing the effect of uncertain terms. Finally, to show the applicability of the proposed method, an inertia pendulum system (with parametric uncertainties in its dynamical equations) is considered and the robust output oscillations are achieved by creating the desirable limit cycle in the close-loop system.

Increasing urbanization, the urban population and consequently the growth of traffic and movement of urban residential with motor vehicles in out within the city has created many problems in transport system. Accordingly to reducing traffic, transport and air pollution implemented variety programs and plans. One such program that with implementation practical and correct can be considerably peace return with transportation is humanities transport development (walking- cycling). Research type is practical and research method is descriptive- analytical and data collection done the method documentary and survey. Research purpose is evaluation natural and physical of Urmia city with purpose spread cycling. Research results shows that in cycling routes select in additional physical factors affect topography and climate factors. According that cycling routes divided with exclusive, semi exclusive and mixed routes. The only in a limited number for the main streets Urmia city (Beheshti, Mafisaheli, Valfajr, Bahonar…) there is the possibility of created cycling.

One of the important issues in the field of decision-making of industrial organizations is determining the optimal time to use equipment. Because premature replacement, additional costs for the organization and late replacement will increase maintenance and repair costs. As a result, equipment management can be shown by using the useful life of the equipment. Now, calculating and identifying the life cycle is essential to determine the optimal life of the equipment. In the current research, the cost of the life cycle for the melting furnace of machines is implemented, the first article is to determine the life cycle cost model and the collection and cost of the costs, and then using the relations of engineering economy, the duration of use of this equipment with the help of the life cycle cost and point to be used. It comes to the head. Finally, after calculations and investigation, it was determined that the company's melting furnace should be removed after 10 years of use. In fact, the use of the life cycle, in addition to determining the time of equipment replacement, helps the managers of industrial organizations in making decisions.