Optimization of Argon Gas Metal Arc Welding Process Parameters with Regard to Tensile Strength for AISI 310 Stainless Steel Using Taguchi Technique

Gas metal arc welding (GMAW) is the leading process in the development of arc welding process for higher productivity and quality. In this study, the effect of process parameters of argon gas welding on the strength of T type welded joint of AISI 310 stainless steel is analyzed. The Taguchi technique is used to develop the experimental matrix and tensile strength of the welded joint is measured using experimental method and finite element method. Optimization of input parameter is performed for the maximum tensile strength of welded joint using ANOVA. The results showed that welding speed is the most significant factor affecting the tensile strength followed by voltage in argon gas metal arc welding (AGMAW) process. Argon gas welding process performance with regard to the tensile strength is optimized at voltage: 18.5 V, wire feed speed: 63 m/min and welding speed: 0.36 m/min.

Symmetry-Breaking in a Porous Cavity with Moving Side Walls

In this paper, a numerical investigation of the steady laminar mixed convection flow in a porous square enclosure has been considered. This structure represents a practical system such as an external through flow of cooled-air an electronic device from its moving sides. The heating was supplied by an internal volumetric source with an uniform distribution at the middle part of its bottom, while the other walls were assumed thermally insulated. Moreover, the momentum transfer in the porous substrate was numerically investigated using the Darcy-Brinkman-Forchheimer law. The governing equations of the posed problem have been solved by applying the finite difference technique on non-uniform grids. For all simulations, the Reynolds number and the porosity have been fixed respectively to Re=100 and φ=0.9. Darcy’s value was varied in the range from 0.001 to 0.1. The results detected the existence of a radical change in the contour patterns for Richardson number equal to 11.76 and 11.77 with fixed Da=0.1. This behavior signified that the fluid is fully convected for higher Darcy number.

Optimal Replacement of Granite Modified with Ife Iron and Steel Slag on Strength Properties of Concrete

Steel is produced from iron ore and purification of metal scrap, leading to manufacture of hundreds of tonnes of steel slag each year. This study investigated the optimum replacement of granite with Ife Iron and Steel Nigeria Limited (ISN) slag that produce maximum Compressive Strength (CS), Split Tensile Strength (STS) and Flexural Strength (FS) of concrete using Response Surface Methodology (RSM) from Design Expert Version 7.0. The outcome of the study showed that the optimum replacement of granite with ISN was 28.85% ISN at 0.47 W/C.

Identifying Contractors’ Planned Quality Time in Egyptian Irrigation Projects

During an extremely competitive infrastructure sector such as irrigation projects, quality time (QT) must be determined to can recognize probable quality crisis parts and to direct mind on schedule enhancement chances. The consciousness of planners on the significance of QT could be reflected in their project schedule. This study appears a measurement of planned QT in five infrastructure irrigation projects performed by different five contractors in Egypt. The aim is to aid the contractors to develop their QT preparation and thus enhance their project time based on the results. QT is fundamental classified into two classes: conformance time (CT), and nonconformance time (NCT). Based on many studies, a register of quality proceedings that would be enclosed in every QT groups are then generated. The QT records for every group are recognized and gathered via questions and questionnaire designs. QT is calculated as a proportion of the project duration. It is uncovered that while enormous companies previously have clear information on QT in construction sector, these times are not scheduled in a defined method during a study of regular QT details. During time classification it is also appeared that greater conformance time (CT) lead to lesser nonconformance time (NCT). It is then ended that a lot of effort is still to be made by the contractors to establish a QT documenting procedure which be able to act as a base for their project enhancement planning.

Competitive Adsorption of Copper, Zinc, and Chromium from Wastewater Using Corn-Cob Ash: Optimization Approach

Corn Cob ash was used in competitive adsorption of copper, zinc, and chromium from wastewater. The central composite design; a sub-set of response surface methodology was used to optimize the adsorption of the heavy metals. The result of the statistical parameters showed the coefficient of determination (R2) of 1.000, 0.999, and 1.000 for copper, zinc, and chromium respectively. The optimal conditions obtained for adsorbent dosage, initial concentration, temperature, contact time, and particle size were 13.20 mg, 79.72 mg/l, 34.95 °C, 40.38 min, and 1400 µm, respectively with the desirability of 1.000. The predicted and the actual values of metal removal obtained were 69.41%, 76.37%, as well as 70.44%, 72.50%, 77.90 % and 71.00% for copper, zinc, and chromium respectively. The ressult indicated a good conformity between the model predicted values and the actual values, thus having small errors of 3.09%, 1.53 % and 0.56 % for copper, zinc, and chromium respectively.

Optimal Setting of Thyristor Controlled Series Compensator with Brain Storm Optimization Algorithms for Available Transfer Capability Enhancement

Applications of Flexible AC Transmission Systems (FACTS) devices for enhancement of Available Transfer Capability (ATC) is gaining attention due to economic and technical limits of the conventional methods involving physical network expansions. FACTS allocation which is sine-qua-non to its performance is a major problem and it is being addressed in recent time with heuristic algorithms. Brain Storm Optimization Algorithms (BSOA) is a new heuristic and predicting optimization algorithms which revolutionizes human brainstorming process. BSOA is engaged for the optimum setting of FACTS devices for enhancement of ATC of a deregulated electrical power system network in this study. ATC enhancement, bus voltage deviation minimization and real power loss regulation are formulated into multi-objective problems for FACTS allocation purposes. Thyristor Controlled Series Capacitor (TCSC) is considered for simulation and analyses because of its fitness for active power control among other usefulness. ATC values are obtained for both normal and N-1-line outage contingency cases and these values are enhanced for different bilateral and multilateral power transactions. IEEE 30 Bus system is used for demonstration of the effectiveness of this approach in a Matlab software environment. Obtained enhanced ATC values for different transactions during normal evaluation cases are then compared with enhanced ATC values obtained with Particle Swarm Optimization (PSO) set TCSC technique under same trading. BSO behaved much like PSO throughout the achievements of other set objectives but performed better in ATC enhancement with 27.12 MW and 5.24 MW increase above enhanced ATC values achieved by the latter. The comparative of set objectives values relative to that obtained with PSO methods depict suitability and advantages of BSOA technique.

Physicochemical Parameters and Suitability for Irrigation of Groundwater Resources from Biskra Area (Southeastern Algeria)

This study is part of the more general framework for diagnosis of the quality of water resources in the Biskra area and its suitability for irrigation. This work reports the results of an analysis of physicochemical groundwater quality. Groundwater samples were collected from 12 boreholes in different aquifers exploited in the area, and used for drinking and domestic purposes. The results showed that the water of the limestone aquifer (Maastrichtian) is better than other aquifers (phreatic, Miopliocene, Lower Eocene). This affects more particularly the pH, conductivity (mineralization), total hardness, and concentration of the major elements. As far as the same aquifers (phreatic, Miopliocene, Lower Eocene), present water which classified mediocre highly mineralized for irrigation because EC > 2250 μS/cm (class 4). The Maastrichtian aquifer presents a poor water quality (class 3), according to the Riverside classification.

Modeling and Control of Grid-Connected Solar-Wind Hybrid Micro-Grid System with Multiple-Input Ćuk DC-DC Converter for Household & High Power Applications

There is a continuous global need for more energy, which must be cleaner than energy produced from the conventional generation technologies. As such, this need has necessitated the increasing penetration of distributed generation technologies and primarily on renewable energy sources. This paper presents a dynamic modeling and control strategy for a sustainable micro-grid, principally powered by multiple renewable energy sources (solar energy, wind energy and Fuel cell), micro sources (such as diesel generator, micro-gas turbine etc.) and energy storage scheme. More importantly, a current-source-interface, multiple-input dc-dc converter is utilized to coordinate the sustainable power sources to the main dc bus. Thus, for tracking maximum power available in solar energy, maximum power point tracking algorithm is applied. The proposed system is designed to meet load demand, manage power flow from various sources, inject excess power into the grid, and charge the battery from the grid as needed. More so, the proposed converter architecture has reduced number of power conversion stages with less component count, and reduced losses compared to existing grid-connected hybrid systems. This improves the efficiency and reliability of the system. The utilization of energy storage is essential owing to the intermittent nature of the renewable energy sources and the consequent peak power shift between the sources and the load. Following this further, a supervisory control system is designed to handle various changes in power supply and power demand by managing power intermittency, power peak shaving, and long-term energy storage. The entire hybrid system is described given along with comprehensive simulation results that reveal the feasibility of the whole scheme. The system model is designed and simulated in MATLAB SimPowerSystem in order to verify the effectiveness of the proposed scheme.

Geochemical, Mineralogical and Isotopic Fracturing during the Progressive Evaporation of Chott Djerid Brine (Southern Tunisia)

Djerid Chott, in southwestern Tunisia, is one of the biggest salt lakes in the world. This work follows the specific precipitation of evaporites through progressive evaporation of Chott Djerid brines using geochemical, isotopic and mineralogical approaches, to explain the intricacy of the working of saline frameworks controlled basically by climatic driving and the underlying geochemical structure acquired from the geographical system. Toward the finish of every evaporation step, solid and liquid samples went through analyses. Djerid brine is remarkably saline (427.7 g/l) and it is supersaturated contrasted with halite. The outcomes indicated that the Chott Djerid brines shaped fundamentally Cl--Na+-SO4- type geochemistry. Added to halite and gypsum as significant minerals, other minor minerals including carnallite, hexahydrite and sylvite were recognized in various phases of progressive evaporation of Djerid brine. Regardless of their low costs, significant minerals are of geo-economic interest because of their high amounts of production. Then, minor valuable minerals secure their geo-economic interest from their excessive costs. In this work, we find the window of precipitation of these valuable minerals' at the evaporation paces of 80% and 100%.

An Artificial - Intelligent - Based System to Automate the Design of Complex Mechanical Products

Over the last decades, there has been growing pressure on industrial companies to offer to their costumers products with high quality, in the minimum deadlines and with reasonable prices. Since the design phase plays a key role to achieve these difficult goals, many traditional, DFX (Design For X) and integrated approaches have been proposed. However, many limits are still present. Thus, the main objectives of this work were first to identify these limits and then to overcome them by proposing and developing an automated framework for integrated product design. In this work, we automated the integrated DFMMA (Design For Materials, Manufacturing and Assembly) approach by developing an architecture composed of four levels, namely: the Common Information Modeling Level, the Selection Systems Level, the Inference and Computation Level and finally the Application Level. The proposed automated system is based on ontologies, on the CBR (Cases Based Reasoning) and the RBR (Rules Based Reasoning). The first main result obtained throughout the contributions consists on the integration of Manufacturing process selection, Assembly solution selection and materials selection in one integrated design approach. The second main result obtained consists on the exploitation of all the previous design studies developed by the design team and the ability to reuse the designers experience throughout the case based reasoning used in the proposed architecture. Another important result consists on the formalization and the automation of the execution of the design rules and the ability to infer new results and to check inconsistencies in the developed product using the data and information modeled in the ontological model and throughout the Cases Based Reasoning that we have incorporated in the developed approach. In this way, the redundancy in work and the difficulties faced in case of having a high number of design alternatives are avoided. Consequently, the product quality increases and wastes of time and money decrease. Finally, to validate the functioning and the efficacy of the proposed DFMMA system, an application on the design of a complex mechanical product is developed in the end of the work.