JECET : Journal of Environmental Science, Computer Science and Engineering & Technology. E-ISSN : 2278-179X

      JECET : Journal of Environmental Science, Computer Science and Engineering & Technology

Research Papers in Eng Science

Experimental Investigation of Xenon Flash lamp Driving Circuit for Nd:YAG Laser

Wasfi. H. Rashid, Bushra. R. Mhdi, Nahla A. Aljabar and Lubna. G. Abdulatif

Experimental investigation in the flash lamp driving circuit parameters are presented for Xenon flash lamp that was used as an optical pumping source for Nd:YAG laser. This is accomplished by designing and construction of power supply for this purpose. A simple circuit of pulse forming network (PFN) consists of (RLC) network used to control the delivered energy to the flash lamp. By determining the energy E0 is to be discharged, and the pulse duration tp, the values of capacitance C, inductance L, and charging voltage V0, are specified to yield a critically damped pulse at 0.8 damping factor values, at which maximum transfer of energy from the capacitor bank to the flash lamp is accomplished. Flash lamp output intensities at various input voltage to the capacitance bank and the flash lamp pulse duration were monitored.

Structural Feature and Chemical Durability of Sodium Aluminium Iron Phosphate Glasses

S. Aqdim, A. Albizane

The relationship between the composition and the structure of(40-y)Na2OyFe2O3-5Al2O3-55P2O5 (5≤y≤20) glasses has been studied. The structure and valence states of the iron ions in the glasses were investigated using differential thermal analysis (DTA), X-ray diffraction (XRD), 57Fe Mössbauer spectrometry,potentiometric analysis and infrared (IR) spectroscopy. The DTA results exhibited a glass transition temperature in the 435–535°C range and a crystallisation temperature in the 543–578°Crange. The XRD pattern indicates that the local structure of iron phosphate glasses is related to the short-range structures of NaFeP2O7,Na7Fe3(P2O7)4, Na7Fe4(P2O7)4, Na3.12Fe2.44 (P2O7), Fe(PO3)3, Al(PO3) and NaAlP2O7. Both Mössbauer spectrometry and potentiometric analysis allowed us to estimate Fe2+ and Fe3+ contents in all of these glasses. IR spectroscopy confirmed the structural tendency change from metaphosphate (Q2) to pyrophosphate structural units (Q1) as the Fe2O3 content increased in the glass from y=5 to y=20. This change indicates the formation of P–O–Fe bonds in the pyrophosphate glasses that replace hydrated P–O–Na bonds. The presence of a small amount of Al2O3 in the glass seems to play a role as a network  modifier. The chemical durability and density of these glasses increase with increasing Fe2O3 content. The dissolution rate (DR), calculated from the weight loss in distilled water at 90°C for up to 20 days, was approximately 3.10-9g cm-2 mn-1, which is 30 times lower than that of window glass. With increasing Fe2O3 content and molar O/P ratio, there is a corresponding reduction in the length of the phosphate units and an increase in the P–O–Fe resistant bands, which cause a high tendency for crystallisation. This latter point seems to be the origin of high chemical durability.

Photon Absorption and Current Realization in Thin Film Micromorph Silicon Solar Cells

Mohammad I. Hossain and Wayesh Qarony

The research addresses the techniques and ways to achieve optimal matched current and cell relationships between two layers for smooth and periodically textured transparent conductive oxide (TCO) in thin-film silicon double junctions solar cells. In addition, to realize efficient light trapping schemes we use periodically textured TCO surface in both single and double junction solar cells. An approach has been introduced to establish a methodology for 2D optical simulation that allows analysing optical losses in the individual layers of a thinfilm solar cell structure. The approach towards micromorph tandem cells includes current realization, dimension of the surface texture profile, and investigations on photon absorption in the cell. Furthermore, we have performed a computer modelling by using commercial Finite-Difference Time-Domain (FDTD) tool where Maxwell's curl equations are rigorously solved for investigating such cells. The investigation has been carried out based on the upper limit external quantum efficiency; short-circuit current, and all absorption losses. Throughout the investigation p-i-n and p-i-n/p-i-n structures have been used that are deposited on glass substrates coated with aluminium doped zinc oxide (ZnO: Al) TCO.

Effects of Cutting Parameters on Cutting Forces: An Experimental Study and Numerical Modeling of Turning Operation by Finite Element Analysis

Ved Prakash Singh Parihar, M. A. Saloda, B.P. Nandwana and M. S. Khidiya

Experimental Investigation and Optimization of the Effect of Cutting Variable on the Cutting Force by Taguchi Approach

Narendra Patel, M.A. Saloda, S Jindal and Chitranjan Agarawal

Higher Dimensional Bianchi Type I String Cosmological Model in Brans-Dicke Theory

Ghanshyam Singh Rathore, Ajit Kumar Bhabor and Mayank Karan Singh Ranawat

Fixed Point Theorem for Occasionally Weakly Compatible Mappings in Cone Metric Space

Namita Soni, Akhilesh Pariya and V.H. Badshah

In this paper, we prove a result that is a common fixed point theorem in cone metric space for occasionally weakly compatible mappings satisfying general contractive condition. Our result extend and generalize some results of Rhoades, Turkoglu et al., Huang and Zhang and Prudhvi.

Five Dimensional Bianchi Type I String Cosmological Models with Bulk Viscous Fluid in Lyra Geometry

Ajit Kumar Bhabor, Mayank Karan Singh Ranawat and Ghanshyam Singh Rathore

Five dimensional Bianchi type-I cosmological model with bulk viscous fluid have been investigated in Lyra geometry. For the determinate solution we have been assumed that ρ=λ . It is interesting to note that as T increases the scalar expansion θ and shear scalar σ2 decreases and finally they vanish when T→∞ . The cosmological parameters have been discussed in detail

Properties of Concrete Containing High Density Polyethylene (Hdpe) Fibre

P .L. Chowdary

Concrete is taken for granted in our everyday activities and tend to be impressed by the more dramatic impacts of technology. The versatility and mould ability of this material its high compressive strength and ability to redistribute the stresses, and the discovery of reinforcing and pressurising techniques which helped to make up for its low tensile strength have contributed largely to its wide spread use. We can rightly say that are in the age of concrete. With the passage of time and due to the fast improving technology, we have seen many improvements and even discoveries of new concrete. Polymer concrete, air entrained concrete, lightweight concrete, vacuum concrete, etc are few to mention among them.

The Investigation of Properties of High-Silica Pentasil-Type Zeolite Modified by GdMgAl2O4 Nanopowder in Methanol Conversion

L.R. Verdiyeva, T.M. Ilyasly, S.E.Mamedov and T.A. Masmaliyeva

A non-ordinary method to obtain p-xylene from a non-hydrocarbon material -methanol in the presence of the modified pentasil was proposed. It was shown that pentasils modified by Gd0,1Mg0,90Al2O4 nanopowderare active catalysts for the synthesis of xylenes from methanol at atmospheric pressure. Para-selectivity of catalysts can be adjusted by changing the concentration of acid sites and adsorption capacity of the zeolite.

Comparison between some Nonparametric Kernel Predictors 

Hayek Afif and Tawbi Khalil

We adapted the preceding results studied by CARBON & DELECROIX (1987), GANNOUN (1990) and especially those done by HAYEK & LECOUTRE (1998), which had shown good results given by non-parametric predictor method; more over they studied the specifications of convergence general predictor. The dependency of a nonparametric predictor on the size of the bloc were studied by PHILIPPE A. (2008) and the result was studied by AMIRI A (2010) on the methods of nonparametric estimation based on recursive kernel. As for us, we continued this study based on certain real and simulated series. A comparison between eight methods of prediction was then made and at each time either the kernel k or the function Ψ were changed. 


We are calling papers for Volume 7 and Issue 4 in all three sections.

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