NISCAIR Online Periodicals Repository Community: IJEMS Vol.19 [2012]

Modeling and analysis by response surface methodology of hardness for submerged arc welded joints using developed agglomerated fluxes

Wed, 28 Nov 2012 22:58:59 GMT

Title: Modeling and analysis by response surface methodology of hardness for submerged arc welded joints using developed agglomerated fluxes

Authors: Kumar, Ajay; Singh, Hari; Maheshwari, Sachin

Abstract: The present study evaluates the hardness of submerged arc welded joints by using developed agglomerated fluxes during submerged arc welding. Response surface methodology (RSM) technique is used to conduct the experiments. Flux constituents MnO, CaF₂, NiO, MgO and Fe-Cr are chosen as variables added into the main constituents CaO, SiO₂ and Al₂O₃ to study the performance in terms of hardness. The results identify the most important constituents favoring the hardness are MnO, MgO, NiO and Fe-Cr, where as CaF₂ is not so prominent to improve the hardness.

Page(s): 379-385

Effect of moisture content on compressive and split tensile strength of concrete

Wed, 28 Nov 2012 22:58:59 GMT

Title: Effect of moisture content on compressive and split tensile strength of concrete

Authors: Chen, Xudong; Huang, Wanshan; Zhou, Jikai

Abstract: The aim of this study is to evaluate the moisture effect on the strength of concrete specimens that has completely cured. This study is also aimed to develop relations that can be used to determine the properties of concrete with different moisture contents that are normally experienced in outside conditions. Numerous compressions and split tensile tests are performed. In order to better understand the results obtained from mechanical tests, a simple empirical formula is suggested that accurately fits experimentally measured sorption data for concrete specimens. Analysis of the collected test results suggests that the moisture content in concrete does have a significant effect on the compressive strength of concrete, but has a much lesser effect on the split tensile strength. As the specimen degrees of saturation increased, the compressive strength fell. However, at nearly saturated condition, an increase in compressive strength can be found.

Page(s): 427-435

Effect of two-springs split injection on the performance and emission characteristics of diesel-oxygenated blends in a DI diesel engine

Wed, 28 Nov 2012 22:58:59 GMT

Title: Effect of two-springs split injection on the performance and emission characteristics of diesel-oxygenated blends in a DI diesel engine

Authors: Kumaresan, M; Devaradjane, G

Abstract: This paper attempts to find the use of two-springs split injection with an oxygenated compound blended with diesel to address the environmental pollution issue especially in smoke and oxides of nitrogen emission reduction besides retaining the performance. Experimental investigation has been carried out to study the performance, and emission characteristics of diesel and diesel-diethyl carbonate oxygenated compounds blend in the proportions of 10% by volume in a direct injection (DI) single cylinder diesel engine using the standard single-spring injection and two-springs split injection. From the investigation it has been observed that with two-springs split injection at an injection timings of 27° before top dead center (BTDC) the brake thermal efficiency is found as 29.3%, oxides of nitrogen emission as 1.32 g/kWh and smoke level as 36% opacity with 10% diethyl carbonate-diesel oxygenated blend.

Page(s): 411-416

Usage of molasses in concrete as a water reducing and retarding admixtur

Wed, 28 Nov 2012 22:58:59 GMT

Title: Usage of molasses in concrete as a water reducing and retarding admixtur

Authors: Yildirim, Hasan; Altun, Baris

Abstract: Molasses is a by-product material like lignosulphonate, which is obtained from paper and sugar industries. Molasses shows plasticizing effect in concrete. In this study a comparison is made between molasses with 40% purity grade and lignosulphonate with respect to the improvements in properties of concrete. Three molasses obtained from different sugar factories are used in this study at two admixture dosages, such as 0.4% and 0.7% of cement dosage. Two types of concretes are prepared with two cement dosages, such as 270 and 320 kg/m³, respectively. The workability and setting times are determined at the fresh state and both compressive and flexural strength properties are measured on hardened concretes. Furthermore, durability properties are compared by using capillary and sulphate resistance tests. Molasses can be used as a Type D, if initial and final setting times and compressive strengths at 35 and 125 days which are measured in this work, are considered, and can be used as Type A because of reducing the dosage of admixture, in concrete in accordance with ASTM C 494 standard.

Page(s): 421-426