Papers by Keyword: Cost

Abstract: The importance of environmental consequences due to diverse substances that are emitted during the production of concrete is recognized, but environmental performance tends to be evaluated separately from the economic performance and durability performance of concrete. In order to evaluate concrete from the perspective of sustainable development, evaluation technologies are required for comprehensive assessment of environmental performance, economic performance, and durability performance based on a concept of sustainable development called the triple bottom line (TBL). Herein an assessment method for concrete eco-efficiency is developed as a technique to ensure the manufacture of highly durable and eco-friendly concrete, while minimizing both the load on the ecological environment and manufacturing costs. The assessment method is based on environmental impact, manufacturing costs, and the service life of concrete.

Abstract: The principal route of success in construction is, according to most experts, economic competitiveness, and the main conditions are: the correct management of cost and quality of construction works and services in the competitive market. Analysis Method and Value Engineering allow the development of competitiveness (efficiency) construction firms in a meaningful, durable and this in an economic environment more complex and evolving. The proposed methodology seeks to solve these problems and give a reply in this regard and create the possibility of reducing the price of construction.

Abstract: This paper aims to provide the economic calculations that were made in order to make a comparison between the old technology used by a company, multi-spindle lathe DAM 6X40 and new technology that should be acquired, CNC lathe Doosan LYNX 220 for processing the part entitled "body of spark plug". The investment in the new technology is urgently needed given the age of the existing technology but the company wants to know in advance what are the costs and how long it would be able to recover the investment. In this regard were calculated the time rate for the operation, economy with direct wages, production capacity, amortization of the fixed assets, cost of the part at the enterprise-level and the return period of additional investment.

Abstract: Optimal allocation of reliability to components of a system is one of the several ways of ensuring high system reliability in design. The problem which is typically formulated as single criterion optimisation encounters difficulty when the analytic system reliability expression is intractable usually as a result of complex system configuration. The current work re-examines a novel approach previously developed by the authors which takes a multicriteria view of the problem on the basis of the minimum cut sets of a system, and thus avoids finding the top level system reliability before optimisation. The model and methodology was applied to two complex system reliability allocation problems: a classical one and one associated with electricity transmission. The results were consistent with previously obtained ones by the authors and with the reliability importance of some notable components.

Abstract: The objective of this research is to investigate the appropriated Tandem Submerged Arc Welding (TSAW) by Punch through technique for high pressure steel tank in ship building industry. Electrode Type AWS A5.17 EM12K and powder flux type AWS A5.17 F7A6 have been applied with electric current at AC+ 550-700 Amp/DC 460-610 Amp. The welding travel speed is controlled between 515-590 mm/min with arc length between 25-30 mm which SM400 steel type is 25 mm thickness. The welding is in horizontal position without any bevel on the steel piece. Studying the suitable parameters from the experiment type 2⁴ of this procedure experiment, the result has been found that the most suitable parameter set up for this welding is DC460, AC550, ST515, AL25. The experiment follows AWS D1.1 standard with 100% full penetration, tensile value at 542.61 N/mm². Welding line supports impact test at 0°C with average value of 66 Joules, average hardness value at 156.4 HV, bending at 180°. With out any defected found. Moreover, this method can be reduced welding cost around18,482 baht/day and also increased the welding lenght around 168%.

Abstract: The construction industry plays significant role in the economy of developing countries, where Lebanon is one of. However, the performance industry remains under critique. Many projects encounter considerable time and cost overruns, fail to realize their intended benefit or even totally terminated and abandoned before or after their completion. As the construction project goes through many phases, the success of each phase will affect the success of the project. Thus, the “Project Success” notion is becoming a priority in the Lebanese construction sector. This paper describes a study of the time, cost and quality management trilogy impact on the success of the local Lebanese construction projects. It shows the importance of each factor and its role in the attainment of client objectives. A Questionnaire survey, supported by “face to face” interviews, elicit the attitude of owners (developers), consultants, and contractors towards the factors affecting each parameter is done. Conclusion and remarks for future construction quality system rating will follow.

Abstract: In this paper are proposed two new approaches to maintenance strategies for Computer Numerical Control (CNC) machine tools. The analysis is done for different families of CNC machine tools from S.C. Elmet Bacau, a company specialized in aviation. In maintenance actions applied to CNC machine tools is very important to know the evolution of defects and critical state of electrical and mechanical components. The results of this analysis concludes that maintenance actions can be judged by the developing time period diagram, between failure appearance and interruptions in operation. It is also analyzed the financial impact, revealed from known maintenance strategies adopted on CNC machine tools, resulting in a positive approach of condition based maintenance.

Abstract: Nowadays the cost effectiveness concept becomes a decision-making and technology evaluation metric. The cost of energy metric accounts for the effect of reliability through levelized replacement cost and unscheduled maintenance cost parameters. One key of the proposed approach is the idea of maintaining the WTs which can be captured via use of a finite state Markov chain. Such a model can be embedded within a probabilistic operation and maintenance simulation reflecting the action to be done. In this paper a finite state Markov model is used for decision problems with number of determined periods (life cycle) to predict the cost according to the option of the maintenance adopted. The minimum cost is taken as the optimal solution.

Abstract: Micro-grid system is an integrated energy system as it consists of distributed energy resources (DERs) and multiple electrical loads operating in parallel or islanded grid. The primary objective of this project is to examine whether Micro-grid implementation can reduce the cost of energy. It can be determined through the modelling bus bar system; 26-Bus Test System. This application can be divided into three aspects which are modelling, simulation and analysis. The power system analysis was conducted under two conditions, steady state condition and contingencies condition using two different methods which are optimal power flow and economic dispatch. Newton-Raphson algorithm was introduced during the power flow analysis. The optimal power flow and economic dispatch for total generation cost was obtained through PowerWorld software simulation.

Abstract: We checker huge quantities of plastic with various forms and types. Major problems caused by these wastes in nature, inside the urban areas and countryside, impose a concern of increasing difficulties for reasons of hygiene and environment Cement concrete is a relatively inert and durable material, compact and waterproof, which can prevent contamination of the environment by living the harmful effects of plastic. In this context it was considered appropriate to include in concrete composition the elements of plastic waste (bag: LDPE) and (bottle: PVC) as a technique for recovery and reuse it’s in the cost. It is a simple and clean procedure to remove these dangerous elements and participate to preserve the nature. Results showed the possibility of using these types of plastic at ambient condition, as a substitution of aggregates, with a slight decrease in compressive strength on the percentage of substitution and an optimal increase in tensile resistance associated with a substantial gain in weight and a high removal rate, especially for PVC. These materials may be intended for the manufacture of components requiring less performance (small works, architectural concrete and decorative elements of the interior, filling, surface coverage and roof.).