Silicon containing electroconductive polymers and structures made therefrom

An electropolymerized film comprised of polymers and copolymers of a monomer is formed on the surface of an anode. The finished structures have superior electrical and mechanical properties for use in applications such as electrostatic dissipation and for the reduction of the radar cross section of advanced aircraft

Fluctuation effects in ternary AB+A+B polymeric emulsions

We present a Monte Carlo approach to incorporating the effect of thermal fluctuations in field theories of polymeric fluids. This method is applied to a field-theoretic model of a ternary blend of AB diblock copolymers with A and B homopolymers. We find a shift in the line of order-disorder transitions from their mean-field values, as well as strong signatures of the existence of a bicontinuous microemulsion phase in the vicinity of the mean-field Lifshitz critical point. This is in qualitative agreement with a recent series of experiments conducted with various three-dimensional realizations of this model system. Further, we also compare our results and the performance of the presently proposed simulation method to that of an alternative method involving the integration of complex Langevin dynamical equations.Comment: minor changes, references adde

Modelling of the pulsatile blood flow in an arterial tree of retinal vasculature

This paper was presented at the 2nd Micro and Nano Flows Conference (MNF2009), which was held at Brunel University, West London, UK. The conference was organised by Brunel University and supported by the Institution of Mechanical Engineers, IPEM, the Italian Union of Thermofluid dynamics, the Process Intensification Network, HEXAG - the Heat Exchange Action Group and the Institute of Mathematics and its Applications.The paper presents a numerical investigation of pulsatile blood flow in arterial vasculatures of a mouse retina using a Womersley model incorporating an appropriate outlet boundary impedance at the end of the terminal vessels of the arterial tree (pre-capillary arterioles). The mouse retinal flatmount was prepared for confocal microscopy and the morphometric information of the vasculature was obtained from the confocal images. The pulsatile analysis focused on one of the arterial trees in the retinal vasculature. We included the in vivo viscosity evaluated from the mathematical models of Fahraues-Lindquist effect and the plasma skimming effect in the microcirculation. Comparative investigations of the pulsatile circulation were carried out for cases of constant viscosity, in vivo viscosity, zero and non-zero outlet boundary impedance. In addition, the dependency of the oscillating input impedance at the inlet of the arterial trees on angular frequencies of the oscillation and vessel elasticises was also studied. The study shows the pulsatile blood flow prediction is largely influenced by the outlet boundary impedance. The oscillating input impedance at the inlet of the arterial tree is also found to be significantly dependent on the angular frequency and the Young modulus of the vessel segment

Total cross sections for neutron-nucleus scattering

Systematics of neutron scattering cross sections on various materials for neutron energies up to several hundred MeV are important for ADSS applications. Ramsauer model is well known and widely applied to understand systematics of neutron nucleus total cross sections. In this work, we examined the role of nuclear effective radius parameter (r$_0$) on Ramsauer model fits of neutron total cross sections. We performed Ramsauer model global analysis of the experimental neutron total cross sections reported by W. P. Abfalterer, F. B. Bateman, {\it et. al.,}, from 20MeV to 550MeV for nuclei ranging from Be to U . The global fit functions which can fit total cross section data over periodic table are provided along with the required global set of parameters. The global fits predict within $\pm 8$ deviation to data, showing the scope for improvement. It has been observed that a finer adjustment of r$_0$ parameter alone can give very good Ramsauer model description of neutron total scattering data within $\pm 4$ deviation. The required r$_0$ values for Ramsauer model fits are shown as a function of nuclear mass number and an empirical formula is suggested for r$_0$ values as a function of mass number. In optical model approach for neutron scattering, we have modified the real part of Koning-Deleroche potentails to fit the neutron total cross sections using SCAT2 code. The modified potentails have a different energy dependence beyond 200MeV of neutron energy and fit the total cross sections from Al to Pb.Comment: 9 pages, 20figures, Poster number ND-1457, ND2010 Conference in Kore

Optical and electronic properties of sub-surface conducting layers in diamond created by MeV B-implantation at elevated temperatures

Boron implantation with in-situ dynamic annealing is used to produce highly conductive sub-surface layers in type IIa (100) diamond plates for the search of a superconducting phase transition. Here we demonstrate that high-fluence MeV ion-implantation, at elevated temperatures avoids graphitization and can be used to achieve doping densities of 6 at.%. In order to quantify the diamond crystal damage associated with implantation Raman spectroscopy was performed, demonstrating high temperature annealing recovers the lattice. Additionally, low-temperature electronic transport measurements show evidence of charge carrier densities close to the metal-insulator-transition. After electronic characterization, secondary ion mass spectrometry was performed to map out the ion profile of the implanted plates. The analysis shows close agreement with the simulated ion-profile assuming scaling factors that take into account an average change in diamond density due to device fabrication. Finally, the data show that boron diffusion is negligible during the high temperature annealing process.Comment: 22 pages, 6 figures, submitted to JA

A Comparison between different Optimization Techniques for CNC End Milling Process

AbstractDifferent kind of statistical optimization techniques are available for optimizing the different parameters of a CNC end milling process. In this paper a comparison is done between five different techniques such as principal components analysis, utility theory, Grey relational analysis, technique of order preference by similarity to ideal solution and their hybrid variants. The Taguchi optimization principle is common to all the methods which are presented in the paper. The experiments were carried out and the different response features such as surface roughness (Ra, Rz and Rq) and material removal rate (MRR) were measured and the different optimization techniques were applied. Three different surface roughness values are used for the analysis and they act as indices of surface quality whereas MRR acts as index of productivity. Hence the optimization is carried out such that the resulting optimized parameters will lead to a compromise between the productivity and the surface quality. The aim of the work is to carry out multi objective optimization on a single process and compare the results

Enhanced Critical parameters of nano-Carbon doped MgB2 Superconductor

The high field magnetization and magneto transport measurements are carried out to determine the critical superconducting parameters of MgB2-xCx system. The synthesized samples are pure phase and the lattice parameters evaluation is carried out using the Rietveld refinement. The R-T(H) measurements are done up to a field of 140 kOe. The upper critical field values, Hc2 are obtained from this data based upon the criterion of 90% of normal resistivity i.e. Hc2=H at which Rho=90%Rho; where RhoN is the normal resistivity i.e., resistivity at about 40 K in our case. The Werthamer-Helfand-Hohenberg (WHH) prediction of Hc(0) underestimates the critical field value even below than the field up to which measurement is carried out. After this the model, the Ginzburg Landau theory (GL equation) is applied to the R-T(H) data which not only calculates the Hc2(0) value but also determines the dependence of Hc2 on temperature in the low temperature high field region. The estimated Hc(0)=157.2 kOe for pure MgB2 is profoundly enhanced to 297.5 kOe for the x=0.15 sample in MgB2-xCx series. Magnetization measurements are done up to 120 kOe at different temperatures and the other parameters like irreversibility field, Hirr and critical current density Jc(H) are also calculated. The nano carbon doping results in substantial enhancement of critical parameters like Hc2, Hirr and Jc(H) in comparison to the pure MgB2 sample.Comment: 25 pages with 9 Figs: comments/suggestions([email protected]

Is intra articular injection of triamcinolone acetonide a better option in management for primary osteoarthritis knee than methylprednisolone acetate?

Background: Intra articular corticosteroid injections are commonly using in management of osteroarthritis of knee. Most commonly used ones are methylprednisolone acetate (MPA) and triamcinolone acetonide (TA). The aim of our study is to compare the efficacy of these two agents in treating osteoarthritis of knee and find out if any one agent is superior to other if so.Methods: Selected patients with symptomatic OA knee with kellgren-Lawrence grade III were given intra articular steroid injections (40 mg TA or 40 mg MPA) and were reassessed on day 0, 1 month, 3 months and 6 months. VAS and Knee society scores were calculated using questionnaire method and compared the scores.Results: The VAS and KSS was improved significantly on day 0,1 month and 6th month and it was found to be increased at 6th month in both the groups and the values were comparable in both the groups. The effect of both the agents last for 3-6 months and the effects found to be maximum at 1st month and the effects starts to wean off at the end of 6 months in both the groups.Conclusions: Both methylprednisolone acetate (MPA) and triamcinolone acetonide (TA) are equally effective in reducing pain in patients with osteoarthritis of knee and thereby improving their functional ability upto 6 months