Experimental investigations of vegetable based cutting fluids with extreme pressure during turning of AISI 304L

Experimental studies on the performances of both new developed environmental friendly vegetable based cutting fluids (refined sunflower and canola oils) including different percentage of extreme pressure (EP) additive and two commercial cutting fluids (semi-synthetic and mineral cutting fluids) in turning processes were reported in this work. Performances of cutting fluids were compared with respect to surface roughness, cutting and feed forces and tool wear during longitudinal turning of AISI 304L. Experimental results were also compared with dry cutting conditions. The results indicated that 8% of EP included canola based cutting fluid performed better than the rest.     

Effects of blended vegetable‐based cutting fluids with extreme pressure on tool wear and force components in turning of Al 7075‐T6

In this study, performances of four different types of vegetable‐based cutting fluids (VBCFs) over a commercial mineral cutting fluid were evaluated for machinability of Al 7075‐T6. Lubrication properties of VBCFs were improved with additive of extreme pressure. Cutting force and tool wear data were obtained for performance analyses of cutting fluids during longitudinal turning of Al 7075‐T6. Cutting, feed and radial forces indicated 1.70–38.25% improvements for VBCFs over the commercial mineral cutting fluid. The lowest average values of flank and nose wears obtained with blended cutting fluid containing 12% of extreme pressure were 0.09 and 0.10 mm, respectively, whereas these values for the commercial mineral cutting fluid were 0.18 and 0.15 mm. The scanning electron microscope results showed adherence of workpiece material occurred on rake and flank faces, and flank and nose wears were the dominant wear modes. It was found that performances of VBCFs during turning of Al 7075‐T6 were better than that of the commercial mineral cutting fluid. Copyright © 2012 John Wiley & Sons, Ltd.     

Thermodynamic analysis of an existing coal-fired power plant for district heating/cooling application

In a conventional coal-fired power plant, which is only designed for electricity generation, 2/3 of fuel energy is wasted through stack gases and cooling water of condensers. This waste energy could be recovered by trigeneration; modifying the plants in order to meet district heating/cooling demand of their locations. In this paper, thermodynamical analysis of trigeneration conversion of a public coal-fired power plant, which is designed only for electricity generation, has been carried out. Waste heat potentials and other heat extraction capabilities have been evaluated. Best effective steam extraction point for district heating/cooling system; have been identified by conducting energetic and exergetic performance analyses. Analyses results revealed that the low-pressure turbine inlet stage is the most convenient point for steam extraction for the plant analyzed.     

Some physical properties of ZnO thin films prepared by RF sputtering technique

ZnO thin films were deposited with RF sputtering using pure Zn target. In order to generate oxidation process of Zn, Ar:O₂ gas mixing in (9:1), (7:3) and (5:5) ratios of Ar:O₂ was used. To characterize ZnO thin films thickness and transparency were measured using optical method, and refractive index and band gap energies were calculated. Electrical conductivity of the ZnO thin films was also determined. AFM images were used to determine surface morphology of produced ZnO thin films.     

Effects of nimodipine and isradipine on endothelin-1-induced contraction of pregnant rat myometrium

Bladder malignancy in the renal transplant recipient is an infrequent occurrence. The 11 previously reported cases reflect an aggressive tumor growth with invasion, requiring partial or complete cystectomy with or without conduit diversion. We report an additional case in a 40-yr-old woman with a living related renal transplant, who experienced rapid progression of her tumor over 3 wk from initial hematuria to a pelvic mass involving the anterior bladder. Her allograft ureter and native ureters, as well as her left iliac vein, became obstructed with tumor in another 2 wk. Biopsy showed poorly differentiated, invasive transitional carcinoma. Attempted resection was abandoned because of finding tumor involvement in most of the pelvis. Chemotherapy was not attempted. She died 2 wk after her attempted resection from tumor burden. Our report presents a collective review of these previously reported 11 cases plus our case. These bladder tumors demonstrate a rapid progression of invasive disease and respond poorly to chemotherapy. There is a possible association of bladder tumors with cyclophosphamide immunosuppression. An aggressive surgical approach should be followed, especially since these tumors present in a younger age group.     

Standard Penetration Test-Based Probabilistic and Deterministic Assessment of Seismic Soil Liquefaction Potential

This paper presents new correlations for assessment of the likelihood of initiation (or “triggering”) of soil liquefaction. These new correlations eliminate several sources of bias intrinsic to previous, similar correlations, and provide greatly reduced overall uncertainty and variance. Key elements in the development of these new correlations are (1) accumulation of a significantly expanded database of field performance case histories; (2) use of improved knowledge and understanding of factors affecting interpretation of standard penetration test data; (3) incorporation of improved understanding of factors affecting site-specific earthquake ground motions (including directivity effects, site-specific response, etc.); (4) use of improved methods for assessment of in situ cyclic shear stress ratio; (5) screening of field data case histories on a quality/uncertainty basis; and (6) use of high-order probabilistic tools (Bayesian updating). The resulting relationships not only provide greatly reduced uncertainty, they also help to resolve a number of corollary issues that have long been difficult and controversial including: (1) magnitude-correlated duration weighting factors, (2) adjustments for fines content, and (3) corrections for overburden stress.     

Corrosion,Wear and Mechanical Properties of Boron Added Cast 304 Stainless Steel

Protection of Metals and Physical Chemistry of Surfaces - The main objective of this research was to examine the effect adding B at 0, 100, 170 ppm had on the mechanical properties, wear and...     

Probabilistic models for the initiation of seismic soil liquefaction

A Bayesian framework for probabilistic assessment of the initiation of seismic soil liquefaction is described. A database, consisting of post-earthquake field observations of soil performance, in conjunction with in situ “index” test results is used for the development of probabilistically-based seismic soil liquefaction initiation correlations. The proposed stochastic model allows full and consistent representation of all relevant uncertainties. including (a) measurement/estimation errors, (b) model imperfection, (c) statistical uncertainty, and (d) inherent variabilities. Different sets of probabilistic liquefaction boundary curves are developed for the seismic soil liquefaction initiation hazard problem, representing various sources of uncertainty that are intrinsic to the problem. The resulting correlations represent a significant improvement over prior efforts, producing predictive relationships with enhanced accuracy and greatly reduced overall model uncertainty.