Influence of annealing temperature on the electrical, structural and surface morphology properties of Au/Cr Schottky contacts on n-type InP

The influence of rapid thermal annealing on the electrical and structural properties of Au/Cr/n-InP Schottky diode havebeen investigated by the current-voltage (I-V), capacitance-voltage (C-V), auger electron spectroscopy (AES) and X-ray diffraction (XRD) measurements. The Schottky barrier height (SBH) and ideality factor (n) of the as-deposited Au/Cr/n-InPSchottky diode are 0.51 eV (I-V)/0.64 eV (C-V) and 1.81, respectively. When the contact is annealed at 200 oC in N2 atmosphere for 1min, a maximum SBH (0.71 eV (I-V)/0.81 eV (C-V)) and low ideality factor (1.15) are achieved for theAu/Cr/n-InP Schottky diode. However, after annealing at 300 oC, the SBH slightly decreases to 0.58 eV (I-V)/0.69 eV (CV), and ideality factor increases to 1.45, respectively. The SBHs obtained from the Norde and Cheungs methods areclosely matched with those obtained from the I-V method. Results show that the optimum annealing temperature for theAu/Cr/n-InP Schottky diode is 200 °C. Further, the discrepancy between SBHs calculated from I-V and C-V methods isalso discussed. Moreover, the energy distribution of interface state density is estimated from forward bias I V characteristics at different annealing temperatures. AES and XRD studies reveal that the formation of indium (In) phasesat Au/Cr and InP interface may be the cause for the increase in SBH after annealing at 200 oC. The AFM results show that the overall surface morphology of Au/Cr Schottky contacts is considerably smooth at elevated tempratures

Radiation and mass transfer effects on unsteady MHD free convection flow of an incompressible viscous fluid past a moving vertical cylinder

The interaction of free convection with thermal radiation of a viscous incompressible unsteady MHD flow past a moving vertical cylinder with heat and mass transfer is analyzed. The fluid is a gray, absorbing-emitting but non-scattering medium and the Rosseland approximation is used to describe the radiative heat flux in the energy equation. The governing equations are solved using an implicit finite-difference scheme of Crank-Nicolson type. Numerical results for the transient velocity, the temperature, the concentration, the local as well as average skin-friction, the rate of heat and mass transfer for various parameters such as thermal Grashof number, mass Grashof number, magnetic parameter, radiation parameter and Schmidt number are shown graphically. It is observed that, when the radiation parameter increases the velocity and temperature decrease in the boundary layer. Also, it is found that as increase in the magnetic field leads to decrease in the velocity field and rise in the thermal boundary thickness

Synthesis, Characterization and Electrochemical Properties of Gold Nanomolecules

Chapter 1 gives a brief introduction to the field of gold nanomolecules. Various synthetic protocols and analytical techniques used through out this dissertation are discussed in detail. Size dependent properties of the gold nanomolecules are described. The structure of gold nanomolecules is explained based on the crystal structure of Au25(SCH2CH2Ph)18. The theoretical basis for the stability of the gold nanomolecules is explained using the super atom complex model and geometric parameters. Chapter 2 includes ligand exchange experiments on gold nanomolecules. Ligand exchange experiments are used to modify the monolayer of nanomolecules after synthesis. Ligand exchange reactions are monitored by mass spectrometry. Exploiting the mass difference of various ligands to monitor ligand exchange reactions is explained. Ligand exchange with dithiols is covered in this chapter. Interstaple vs intrastaple dithiol binding, optimum chain length for bidentate binding and effect on optical properties are studied in this project. Ligand exchange with other chalcogenide ligands like tellurides is discussed briefly. Chapter 3 covers the core size conversion reactions in gold nanomolecules. When gold nanomolecules are etched in excess thiols at elevated temperatures, some of the gold nanomolecules convert to a different size. Such change in core size is called core size conversion. Core size conversion in the larger and smaller sizes is studied in this project. Etching reactions are similar to ligand exchange except that they are more rigorous and performed at elevated temperatures. The use of core size conversion reactions as high yield synthetic protocols is explained. Some mechanistic details based on the mass spectrometric results are discussed. Chapter 4 covers the electrochemical properties of gold nanomolecules. The electrochemical behavior of gold nanomolecules is probed by voltammetry experiments. Cyclic voltammetry and differential pulse voltammetry are the primary techniques used for this purpose. The size dependence of electrochemical properties is demonstrated with different sizes. Solvent effects and the effect of alloying are also covered in detail. Chapter 5 covers mass spectrometry of gold nanomolecules. MALDI MS and ESI MS are the primary analytical techniques used to find the composition of gold nanomolecules. These techniques are increasingly used for studying synthesis, ligand exchange, alloying and fragmentation of gold nanomolecules. These techniques have several advantages and disadvantages for various applications. Applications of mass spectrometry tools for different applications are discussed with several case studies. Chapter 6 covers separation of gold nanomolecules by size exclusion chromatography. Size exclusion chromatography is the most efficient technique for separation of gold nanomolecules. Separation of different gold nanomolecules using size exclusion chromatography is described in this chapter. Advantages of size exclusion chromatography over conventional solvent fractionation techniques are demonstrated with examples. Chapter 7 highlights the contributions of this dissertation work to the field of gold nanomolecule research. Possible improvements and future directions of this research are presented

A NEW NAPHTHOQUINONE ISOLATED FROM POLYGONUM MULTIFLORUM (POLYGONACEAE)

Objective: This research is mainly focused towards isolation and structural elucidation of pure compounds from the extract and fractions of Polygonum multiflorum through silica gel column chromatography.Methods: The air dried rhizomes were extracted with Me2CO (acetone), MeOH (methanol) and H2O (water). The Me2CO extract was fractionated into CHCl3 (chloroform) and residue. The chloroform-soluble portion and MeOH extract were subjected to silica gel column chromatography for the isolation of pure compounds. The isolated compounds were then determined by the use of spectroscopic analysis of HRFABMS, 1H, 13C NMR, UV and IR spectra.Results: CHCl3 soluble portion of Me2CO and MeOH extract of P. multiflorum led to the isolation of one new naphthoquinone and eight known compounds including four anthraquinones, one naphthoquinone and two stilbenes.Conclusion: The obtained results will be very useful for the further evaluation various biological studies

Comparative Analysis of Grid side Converters for Leakage Current Reduction

Design of grid side converters comprises of galvanic isolation between the grid and DC supply .Now a days, for low power applications are effecting more because of high leakage current due to parasitic effect between grid and DC supply, in order to limit the ground leakage current (which deteriorates the power quality and generates EMI), new converter topologies have been proposed. This paper proposes the comparative analysis of H5 and H6 topologies in the aspects of leakage current reduction, parasitic capacitance effect and voltage balancing across the dc mains. The performances of the topologies are also analyzed by implementing modulation techniques. Simulated and tabulated results of H5 and H6 topologies conclude the performance evaluation

Učinkovitost biljnih dodataka prehrani na svojstva trupa, masnokiselinski sastav i kvalitetu mesa tovnih pilića

The present investigation was carried out to determine the effect of two herbal formulations, AV/LMP/10 (T1) (garlic, Allium sativum) and AV/HLP/16 (T2) (mixture of gugal, Commiphora mukul and fenugreek, Trigonella foenum-graecum with 50:50%), on the carcass characteristics, proximate composition, lipid profile including fatty acids, and meat quality attributes in Vencobb 400 broiler chickens. Broilers fed with the AV/HLP/16 (T2) formulation had significantly (P<0.05) superior carcass characteristics in terms of pre-slaughter weight, head, neck, shank, skin, stomach, intestine, giblet, and wholesale cut yield than the control and broilers supplemented with AV/LMP/10 (T1). Meat obtained from the broilers fed with the T2 formulation had a significantly (P<0.01) higher dressing percentage and lean percentage than the control broilers and the T1 supplemented broilers. Meat obtained from the broilers fed with the T2 formulation had significantly (P<0.01) higher moisture and protein content, and lower fat content than the control birds. Meat obtained from the broilers fed with the T2 formulations had significantly (P<0.01) lower triglycerides and higher phospholipids and cholesterol content than meat obtained from the control birds. A significant (P<0.01) increase was observed in the myristic, palmitic, oleic, palmitoleic, linoleic and behenic acid percentages, and a decrease in the stearic acid percentage in meat obtained from the broilers fed with the T2 formulation. Addition of the T2 formulation significantly (P<0.01) improved the physico-chemical quality and sensory scores of the chicken meat. The results of this study revealed that addition of herbal formulations had a significant effect on the carcass characteristics, proximate composition, fatty acid profile and meat quality attributes in comparison with the control birds.Ovo je istraživanje provedeno kako bi se ustanovio učinak dviju biljnih formulacija, AV/LMP/10 (skupina T1) (češnjak, Allium sativum) i AV/HLP/16 (skupina T2) (mješavina dobivena od stabla smirne mukul (Commiphora mukul) i piskavice (Trigonella foenum-graecum) u omjeru 50 : 50 %) na svojstva trupa, kemijski sastav - uključujući lipidni status i masnokiselinski sastav te kvalitetu mesa Vencobb 400 tovnih pilića. U odnosu na piliće kontrolne skupine i onih hranjenih formulacijom AV/LMP/10 (T1), pilići hranjeni formulacijom AV/HLP/16 (T2) imali su znakovito (P<0,05) kvalitetnija svojstva trupa s obzirom na tjelesnu masu prije usmrćivanja te dijelove trupa kao što su glava, vrat, bataci, koža, organi trbušne šupljine, crijeva, iznutrice i veleprodajni komadi pilića. Tovni pilići u skupini T2 imali su znakovito veći (P<0,01) postotak mesa od kontrolne skupine i skupine T1. Meso pilića iz skupine T2 imalo je znakovito veći (P<0,01) sadržaj vode i proteina te manji sadržaj masti od pilića u kontrolnoj skupini. Meso tovnih pilića u skupini T2 imalo je znakovito manje vrijednosti (P<0,01) triglicerida i veće vrijednosti fosfolipida i kolesterola nego meso pilića u kontrolnoj skupini. Znakovit je bio porast (P<0,01) postotka miristinske, palmitinske, oleinske, palmitoleinske, linoleinske i behenske kiseline te smanjenje vrijednosti stearinske kiseline u mesu tovnih pilića iz skupine T2. Dodatak biljne formulacije u skupini T2 znakovito je poboljšao (P<0,01) fizikalno-kemijska i senzorička svojstva mesa tovnih pilića. Rezultati ovog istraživanja pokazali su da dodatak biljnih formulacija prehrani tovnih pilića znakovito utječe na svojstva trupa, kemijski - uključujući lipidni i masnokiselinski sastav te kvalitetu mesa pilića u odnosu na kontrolnu skupinu

The costs of HIV prevention for different target populations in Mumbai, Thane and Bangalore.

BACKGROUND: Avahan, the India AIDS Initiative, delivers HIV prevention services to high-risk populations at scale. Although the broad costs of such HIV interventions are known, to-date there has been little data available on the comparative costs of reaching different target groups, including female sex workers (FSWs), replace with 'high risk men who have sex with men (HR-MSM) and trans-genders. METHODS: Costs are estimated for the first three years of Avahan scale up differentiated by typology of female sex workers (brothel, street, home, lodge based, bar based), HR-MSM and transgenders in urban districts in India: Mumbai and Thane in Maharashtra and Bangalore in Karnataka. Financial and economic costs were collected prospectively from a provider perspective. Outputs were measured using data collected by the Avahan programme. Costs are presented in US$2008. RESULTS: Costs were found to vary substantially by target group. Non-governmental organisations (NGOs) working with transgender populations had a higher mean cost (US$116) per person reached compared to those dealing primarily with FSWs (US $75-96) and MSWs (US$90) by the end of year three of the programme in Mumbai. The mean cost of delivering the intervention to HR-MSMs (US $42) was higher than delivering it to FSWs (US$37) in Bangalore. The package of services delivered to each target group was similar, and our results suggest that cost variation is related to the target population size, the intensity of the programme (in terms of number of contacts made per year) and a number of specific issues related to each target group. CONCLUSIONS: Based on our data policy makers and program managers need to consider the ease of accessing high risk population when planning and budgeting for HIV prevention services for these populations and avoid funding programmes on the basis of target population size alone

Radiation and mass transfer effects on an unsteady MHD free convection flow past a heated vertical plate in a porous medium with viscous dissipation

An unsteady, two-dimensional, hydromagnetic, laminar free convective boundary-layer flow of an incompressible, Newtonian, electrically-conducting and radiating fluid past an infinite heated vertical porous plate with heat and mass transfer is analyzed, by taking into account the effect of viscous dissipation. The dimensionless governing equations for this investigation are solved analytically using two-term harmonic and non-harmonic functions. Numerical evaluation of the analytical results is performed and graphical results for velocity, temperature and concentration profiles within the boundary layer and tabulated results for the skin-friction coefficient, Nusselt number and Sherwood number are presented and discussed. It is observed that, when the radiation parameter increases, the velocity and temperature decrease in the boundary layer, whereas when thermal and solutal Grashof increases the velocity increases

Effect of Nymphaea meal incorporated diets on growth, feed efficiency and body composition in fingerlings of Cyprinus carpio L.

The effect of varying levels of Nymphaea leaf meal on the growth and survival of common carp, Cyprinus carpio was investigated. In a feeding trail of 45 days, three experimental diets containing nymphaea leaf meal at 300, 400 and 500g kg-1 level of incorporation were fed to triplicate groups of 10 fish each. The conventional feed used in India, consisting of a mixture of groundnut oil cake and rice bran in 1:1 ratio served as the control. Best growth in terms of weight gain (35.2g), specific growth rate (4.67), protein efficiency ratio (PER) (2.7), feed conversion ratio (FCR) (2.5) was obtained for the test diet with 400g kg-1 nymphaea meal inclusion level. However no statistical difference was observed between the three experimental diets. Digestive enzyme activity and digestibility studies also indicated the same pattern. Thus the results of the present study indicate that a diet of 300g kg-1 overall protein with nymphaea meal included at 400g kg-1 can elicit good growth response and survival in common carp

Thermal Radiation Effects on Mhd Free Convection Flow of a Micropolar Fluid Past a Stretching Surface Embedded in a Non-Darcian Porous Medium

A comprehensive study of thermal radiation on a steady two-dimensional laminar flow of a viscous incompressible electrically conducting micropolar fluid past a stretching surface embedded in a non-Darcian porous medium is analyzed numerically. The governing equations of momentum, angular momentum, and energy equations are solved numerically using Runge- Kutta fourth order method with shooting technique. The effects of various parameters on the velocity, microrotation, and temperature field as well as skin friction coefficient, and Nusselt number are shown graphically and in tabulated. It is observed that the micropolar fluid helps in the reduction of drag forces and also acts as a cooling agent. KEYWORDS: Micropolar fluid, Free convection, Darcy number,Radiation, MHD,  Porous medium