Evaluation of Earth Dam Leakage Considering the Uncertainty in Soil ‎Hydraulic Parameters

Analysis of earth dams is generally conducted in three stages of stability, deformability and water penetration analysis. Lack of sufficient attention to leakage, as one of the most important issues, leads to erosion and destruction of slope stability. The aim of current paper is to analyze the earth dam leakage with respect to the existing uncertainty in soil hydraulic parameters. In this research, the Monte Carlo (MC) method was used to calculate soil hydraulic parameters. Using these parameters, analysis of Alborz earth dam leakage by means of SEEP/W model based on the finite elements method was investigated. Due to the hydraulic conditions of the core soil, the total head value, pore water pressure, and water flux in core region will change. The results indicate that uncertainty in the hydraulic parameters of Alborz earth dam are significant, thus risk is important in this dam. The application of the proposed methodology in estimation of leakage from Alborz earth dam in Mazandaran province reveals its efficiency and proper accuracy in predicting the amount of leakage flow in earth dams with respect to the possible changes in the hydraulic parameters of the soil. Moreover, it was found that the quantity of seepage increases considerably when the dam is without core, therefore, the core is very necessary to decrease the value of seepage through the earth dam

Investigation of k-ε Turbulent Models and Their Effects on Offset Jet Flow Simulation

In the case in which relatively low thickness and high-velocity flow enter into the lower velocity fluid, the resulting interference field of these two flows is called the jet. This phenomenon is the dominant output of power plants and some of the dams. The jets can be divided into two categories of free jets and confined jets, caused by the distance from the discharge to limited boundaries points. The offset jet is a type of confined jet in which both free surface and wall boundaries are near the diffusion location. The jet flow due to the extreme curvature in the main flow path and the proximal portion of this flow with solid boundaries have characteristics that make it difficult to solve with simple turbulence models.In this research, the offset jet phenomenon and related issues have been investigated. For this purpose, the offset jet flow pattern and probable factors in the complexity of this model have been simulated using Fluent software which analyses fluid flow in a two dimensional and three dimensional finite volume method. The simulation of offset jet flow pattern has been performed with a focus on investigating different models of turbulence k-ε, also boundary conditions, various wall functions and other effective coefficients in the numerical model and the model results compared with test case data findings and validating results, the necessary approaches in numerical simulation of this phenomenon for using in the next stages had been taken

ACO-tagger: A Novel Method for Part-of-Speech Tagging using Ant Colony Optimization

Swarm Intelligence algorithms have gained significant attention in recent years as a means of solving complex and non-deterministic problems. These algorithms are inspired by the collective behavior of natural creatures, and they simulate this behavior to develop intelligent agents for computational tasks. One such algorithm is Ant Colony Optimization (ACO), which is inspired by the foraging behavior of ants and their pheromone laying mechanism. ACO is used for solving difficult problems that are discrete and combinatorial in nature. Part-of-Speech (POS) tagging is a fundamental task in natural language processing that aims to assign a part-of-speech role to each word in a sentence. In this research paper, proposed a high-performance POS-tagging method based on ACO called ACO-tagger. This method achieved a high accuracy rate of 96.867%, outperforming several state-of-the-art methods. The proposed method is fast and efficient, making it a viable option for practical applications

A High Gain AC-DC Rectifier Based on Current-Fed Cockcroft-Walton Voltage Multiplier for Motor Drive Applications

This paper proposes a novel high-gain AC-DC converter based on the Cockcroft-Walton (CW) voltage multiplier which can be utilized in motor drive systems with low input voltage. In this topology, use of the voltage multiplier and boost circuit results in the increment of converter gain which has a significant impact on the cost and efficiency of the system. Moreover, in this converter, the AC voltage is directly changed to DC voltage using the switching method in high frequency and, as well, the power factor is corrected. Besides, this high-frequency converter contributes to the reduction of output ripple. On the other hand, cost efficiency, the low voltage stress on capacitors and diodes, compactness, and the high voltage ratio, are achieved from the Cockcroft-Walton circuit. Furthermore, the hysteresis method is presented for converter switching to correct the power factor. The converter is simulated in MATLAB software to demonstrate the effectiveness of the suggested method. Lastly, a laboratory prototype of the suggested converter is built, several tests are done in order to verify the theoretical analysis, and comprehensive comparison with the state-of-the-art converter is done.© 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).fi=vertaisarvioitu|en=peerReviewed

Optimal Robust LQI Controller Design for Z-Source Inverters

This paper investigates the linear quadratic integral (LQI)-based control of Z-source inverters in the presence of uncertainties such as parameter perturbation, unmodeled dynamics, and load disturbances. These uncertainties, which are naturally available in any power system, have a profound impact on the performance of power inverters and may lead to a performance degradation or even an instability of the system. A novel robust LQI-based design procedure is presented to preserve the performance of the inverter against uncertainties while a proper level of disturbance rejection is satisfied. The stability robustness of the system is also studied on the basis of the maximum sensitivity specification. Moreover, the bat algorithm is adopted to optimize the weighting matrices. Simulation results confirm the effectiveness of the proposed controller in terms of performance and robustness

Effect of Bentonite Addition on Geotechnical Properties of Oil-Contaminated Sandy Soil

Oil and its derivatives not only change the chemical and biological properties of the soils, but also affect their geotechnical properties. Effects of oil contamination on a sandy soil which mixed with bentonite was assessed in terms of compaction, shear strength, and consolidation behavior. The experiments were carried out by polluting dry sandy soil with 2.5, 5, 7.5, 10% w/w crude oil at different bentonite contents (0, 5, 10, 15, 20% w/w). Results of compaction tests indicated that at a fixed bentonite content, with increasing crude oil content, the maximum dry density increases, while the optimum water content decreases. Similarly, at a fixed contaminant content, increasing the bentonite content in the soil leads to increase in soil maximum dry density and the optimum moisture content. Moreover, direct shear tests revealed that at a specific bentonite content, higher contamination concentration causes lower internal friction angle. The effect of oil content on the coefficient of consolidation (Cv) and void ratio of soils with 0, 5, 10, 15, and 20 percent bentonite contents was studied. The results of consolidation tests indicated that at a fixed bentonite content Cv has an overall increasing pattern which is in its maximum amount at 5% oil content

RUSSIAN FEDERATION GEO-ECONOMIC IMPACT AND POLITICAL RELATIONSHIP IN SHANGHAI COOPERATION ORGANIZATION AND ITS INFLUENCE IN THE ENERGY MARKET

This study is in regards to Russia Geo-economic interest and influence in Shanghai Cooperation Organization and the importance of SCO as a sufficient Eurasian organization’s leadership in energy market and the prospective of Russia to affect the energy market and energy reserve as a major authority within the organization

Evaluating Properties of Asphalt Mixtures Containing polymers of Styrene Butadiene Rubber (SBR) and recycled Polyethylene Terephthalate (rPET) against Failures Caused by Rutting, Moisture and Fatigue

Properties of asphalt mixture play a vital role in structural integrity and performance of flexible pavements structure. In flexible pavements asphalt concrete surface layer consists of asphalt binder, aggregates and in some cased additives. In this research study styrene butadiene rubber (SBR) and recycled polyethylene terephthalate (rPET) used to evacuate their individual and also their combination effects upon moisture susceptibly, rutting and low temperature cracking of asphalt concrete mixture. Three combination of SBR and rPET along with water were vulcanized to from thermoplastic elastomer polymers as bitumen modifier. Then conventional bitumen tests including penetration grade, softening point and rotational viscosity (RV) as well as asphalt mixture tests including resilient modulus, dynamic creep, IDT fatigue and moisture susceptibility tests were performed on binders and asphalt mixture specimens. The test results indicated that SBR and rPET increase viscosity and softening point and stiffen the binders by reducing their penetration grade. Test results of spearmens prepared with modified binders showed higher tensile strength and higher rutting resistance than that of control specimen within the contest of this study it is conclude that modification of bitumen with SBR reduces low temperature stiffness of binder and hence reduces failure of thermal cracking and modification with rPET increases rutting resistance of the mixture at high temperatures

Results of a Randomized, Open-Label, Clinical Trial Investigating the Effects of Supplementation with Heracleum persicum

The present study evaluated the potential benefit of supplementation with Heracleum persicum as an adjunctive therapy to atorvastatin in dyslipidemic subjects. In a randomized, open-label, clinical trial, 100 dyslipidemic subjects were randomly assigned to: (1) H. persicum group (n = 50, completers = 18), receiving H. persicum extract (500 mg/day) + atorvastatin (10 mg/day) for 8 weeks, or (2) atorvastatin group (n =50, completers= 34), receiving only atorvastatin (20 mg/day) for 8 weeks. Weight, body mass index (BMI), lipid profile, and biomarkers of hepatic and renal injury were determined at baseline and at the end of the trial. There were significant reductions in serum total cholesterol and LDL-C in both the H. persicum (p = 0.001) and atorvastatin (p 0.05). Serum triglyceride levels remained statistically unchanged by the end of the trial in both groups (p > 0.05). Serum alanine (p = 0.049) and aspartate aminotransferase (p = 0.013) levels rose in the atorvastatin, but not the H. persicum (p > 0.05) group. In comparison with baseline values, no significant change was observed in weight and BMI, as well as serum levels of creatinine, blood urea nitrogen, and fasting blood sugar in either of the groups (p > 0.05). Apart from HDL-C, the effects of atorvastatin (20 mg/day) on other lipid profile parameters do not appear to be significantly superior to those achieved by combination therapy with H. persicum + atorvastatin (10 mg/day)

Targeting the balance of T helper cell responses by curcumin in inflammatory and autoimmune states

CD4+ T helper (Th) cells are a crucial player in host defense but under certain conditions can contribute to the pathogenesis of inflammatory and autoimmune diseases. Beside the Th1/Th2 subset, several additional Th subsets have been identified, each with a distinctive transcription factor, functional properties, signature cytokine profile, and possible role in the pathophysiology of diseases. These newer Th subsets include Th17, regulatory Th cells (Tregs), and more recently, Th9, Th22, and follicular T helper cells. Interestingly, imbalance of Th subsets contributes to the immunopathology of several disease states. Therefore, targeting the imbalance of Th subsets and their signature cytokine profiles by a safe, effective and inexpensive nutraceutical agent such as curcumin could be helpful to treat autoimmune and inflammatory diseases. In this study different Th subsets and how the imbalance of these subsets could promote pathology of several diseases has been reviewed. Furthermore, the role of curcumin in this process will be discussed and the impact of targeting Th subsets by curcumin