Evaluation of Soya Bio-Diesel as a Gas Turbine Fuel

In the recent past, the crude oil prices have increased immensely as the fossil fuels are depleting, biodiesel has emerged as an alternative fuel for the petroleum. In this context the use of bio-diesel in the gas turbine seems a solution for power generation problems and their environmental concerns. Vegetable oils, due to their agricultural origin, are able to reduce net carbon dioxide emissions to the atmosphere. However, there are several operational and durability problems which may arise in using straight vegetable oils, which are because of their higher viscosity and low volatility compared to mineral diesel fuel. Bio-fuels, an alternative fuels are having environmental benefit as; they are made from renewable sources. It can be blended in any proportion with mineral Diesel. Many performance and emission tests are being carried out in reciprocating diesel engines that use bio fuel but there are very few tests has been done on gas turbine engines. The gas turbine combustion is steady flame combustion. This feature creates the wide range for the different alternative fuels for clean combustion in the gas turbine, such as natural gas, petroleum distillates, pyrolysis wood gas, biogas of methanisation, bio-diesel etc. The present work is an analysis of the Soya bio-diesel productionprocess i.e. trans-esterification, the different parameters affecting on trans-esterification. The different physical and chemical properties of this bio-diesel and diesel has been determined and compared to establish the suitability of the bio-diesel in the gas turbine. An analysis on High Performance Liquid Chromatography (HPLC) has been done to find out the composition of the different fatty acid esters. The effect of these fatty acids onthe property of the bio-diesel has also been explained such as viscosity, heat of combustion, cetane No, cold flow properties, lubricity and oxidative stability etc. This will also help us to select best suited bio-diesel for the gas turbine

Actinic keratoses show variable histological basal growth patterns - a proposed classification adjustment

Background: Common histological classification schemes of actinic keratoses (AK) do not evaluate growth patterns at basal epidermal aspects of AK. Until now, the importance of basal epidermal growth patterns of AK has not been studied. Objective: To investigate the extent of atypical keratinocytes throughout the epidermis and variation in basal growth patterns of AK. Methods: AK lesions occurring on the head/face from patients seen in routine practice were assessed histologically. We determined histological grade (AK I-III), basal growth patterns of atypical keratinocytes (crowding, budding, papillary sprouting) and accompanying parameters. Results: Of the 246 lesions included, 28.0% were histologically classified as AK I, 46.7% as AK II, and 25.2% as AK III. 26.4% of the basal growth patterns were classified as crowding (pro I), 49.6% as budding (pro II), 17.9% as papillary sprouting (pro III) and 6.1% without basal directed growth. No significant correlation of the histological AK I-III grading and underlying growth patterns was observed (P= 0.4666). However, adnexal structure involvement (OR= 2.37; 95%CI 1.21-4.65), infiltration (OR= 2.53; 95%CI 1.31-4.90) and increased number of vessels (OR= 2.56; 95%CI 1.42-4.65) were independent positive predictive markers for pro II and pro III basal growth patterns. Conclusions: Basal growth patterns (pro I-III) in AK do not correlate with the established AK I-III histological grading system. Besides the degree of upward extension, varying degrees of downward extension exist. Histological classification should consider both, upwards and downward growth patterns when assessing AK

Heavy-light meson spectrum with and without NRQCD

Results for the spectrum of S and P-wave charmed mesons are obtained in the quenched approximation from a tadpole-improved anisotropic gauge field action and a D234 quark action. This is compared to the spectrum obtained from an NRQCD charm quark and a D234 light antiquark. NRQCD results for bottom mesons are also discussed.Comment: 4 pages, 5 figures. Lattice 2000 (Heavy Quark Physics

The charmed and bottom meson spectrum from lattice NRQCD

The mass spectrum of S and P-wave mesons containing a single heavy quark has been computed using quenched lattice nonrelativistic QCD. Numerical results have been obtained at first, second and third order in the heavy quark expansion, so convergence can be discussed. The computed spectrum of charmed and bottom mesons is compared to existing model calculations and experimental data.Comment: 4 pages, 3 figures. To be published in the proceedings of the 4th International Conference on Hyperons, Charm and Beauty Hadrons, Valencia, Spain, 27-30 Jun 200

Effects of bearing clearance on the chatter stability of milling process

In the present study, the influences of the bearing clearance, which is a common fault for machines, to the chatter stability of milling process are examined by using numerical simulation method. The results reveal that the presence of bearing clearance could make the milling process easier to enter the status of chatter instability and can shift the chatter frequency. In addition, the spectra analysis to vibration signals obtained under the instable milling processes show that the presence of bearing clearance could introduce more frequency components to the vibration responses but, however, under both the stable and instable milling processes, the generated frequency components will not violate the ideal spectra structures of the vibration responses of the milling process, which are usually characterized by the tooth passing frequency and its associated higher harmonics for the stable milling process and by the complex coupling of the tooth passing frequency and the chatter frequency for the instable milling process. This implies that, even under the case with bearing clearance fault, the stability of the milling process can still be determined by viewing the frequency spectra of the vibration responses. Moreover, the phenomena of the chatter frequency shift and the generation of more components provide potential ways to detect the bearing clearance in machines. (C) 2010 Elsevier Ltd. All rights reserved

Physics Prospects at the Hadron Colliders

I start with a brief introduction to the elementary particles and their interactions, Higgs mechanism and supersymmetry. The major physics objectives of the Tevatron and LHC colliders are identified. The status and prospects of the top quark, charged Higgs boson and superparticle searches are discussed in detail, while those of the neutral Higgs boson(s) are covered in a parallel talk by R.J.N. Phillips at this workshop.Comment: 16 pages Latex + 15 figures (available on request

Study of Photoluminescence Behaviour of Porous Silicon Samples Prepared at 20 mA Current Density

The paper presents a study on a series of porous silicon films of various thicknesses, prepared at 20 mA current density using a photoluminescence fitting model to determine the average crystallite size of sphe-rical shaped interconnected silicon quantum dots. Discrepancy in photoluminescence behavior of the samples is well explained with this model. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3097

Optical Dispersion In Annealed Thin Films of S-doped a-Si:H Alloys

S-doped amorphous hydrogenated silicon (a-Si,S:H) thin films were prepared by conventional PECVD method on corning glass substrates. The prepared thin films were subsequently annealed in vacuum (~ 2 × 10 – 6 Torr) in the temperature range from 100 °C to 500 °C. The annealing effects at room temperature were examined by means of optical transmission spectra of the films in the wavelength range 300-1100 nm. Dispersion in optical constants such as transmittance, bandgap and refractive index were observed. Tailoring in optical constants was observed with respect to doping concentrations as well as the annealing temperatures. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3097

Normal mode analysis for scalar fields in BTZ black hole background

We analyze the possibility of inequivalent boundary conditions for a scalar field propagating in the BTZ black hole space-time. We find that for certain ranges of the black hole parameters, the Klein-Gordon operator admits a one-parameter family of self-adjoint extensions. For this range, the BTZ space-time is not quantum mechanically complete. We suggest a physically motivated method for determining the spectra of the Klein-Gordon operator.Comment: 6 pages, no figure, late