Theory of Inhomogeneous Rod-like Coulomb Fluids

A field theoretic representation of the classical partition function is derived for a system composed of a mixture of anisotropic and isotropic mobile charges that interact via long range Coulomb and short range nematic interactions. The field theory is then solved on a saddle-point approximation level, leading to a coupled system of Poisson–Boltzmann and Maier–Saupe equations. Explicit solutions are finally obtained for a rod-like counterion-only system in proximity to a charged planar wall. The nematic order parameter profile, the counterion density profile and the electrostatic potential profile are interpreted within the framework of a nematic–isotropic wetting phase with a Donnan potential difference.

Theory of Inhomogeneous Calamitic Coulomb Fluids

A field theoretic representation of the classical partition function is derived for a system composed of a mixture of anisotropic and isotropic mobile charges that interact via long range Coulomb and short range nematic interactions. The field theory is then solved on a saddle-point approximation level, leading to a coupled system of Poisson-Boltzmann and Maier-Saupe equations. Explicit solutions are finally obtained for a calamitic counterion-only system in proximity of a charged planar wall. The nematic order parameter profile, the counterion density profile and the electrostatic potential profile are interpreted within the framework of a nematic-isotropic wetting phase with a Donnan potential difference.

PREFORMULATION STUDIES USING LACTOSE IN DEVELOPMENT OF SOLID ORAL DOSAGE FORM: A GRAPHICAL REPRESENTATION USING SeDeM METHOD

Objective: The objective of the study is to evaluate and present lactose scientifically as an excipient of choice in formulation development of solid orals dosage form for direct compression method. Present work will establish the ability of lactose as an excipient to be the choice of candidate while developing formulation having poor flow API using direct compression process. In addition to this different type of lactose is processed using secure development method (SeDeM) in order to evaluate best suitable type of lactose amongst its different type.Methods: Lactose anhydrous, lactose monohydrate and Lactose spray dried (SD) were employed for evaluation using SeDeM method, twelve different selected pharmacotechnical parameters were determined experimentally and were treated mathematically and expressed in the graphical representation as SeDeM diagram. Parameter index, parameter profile index and good compression index values were calculated.Results: Good compression index was found to be 6.06,5.72,6.83 parameter index was 0.25, 0.42, 0.17 and parameter profile index found to be 6.36,6.01,7.18 for lactose anhydrous, lactose monohydrate and Lactose SD respectively.Conclusion: This research work reveals that data obtained will be useful for the pharmaceutical industries while formulating the drug product and will reflect the scientific characteristics of this excipient as well. This will enable the availability of values obtained after performing SeDeM studies on lactose to scientific society based on the results researchers can use establised data and statistics in their pre-formulation studies to incorporate lactose with confidence and can be justified scientifically in the development formulation of the direct compression process and API having poor flow. Results indicating good direct compression characteristics of the all 3 type of lactose, and Lactose SD can be preferred amongs these 3 types.Â

Landau theoretical analyses of phase transitions and ferroelec-tricity in antiferroelectric ferroics

This paper presents Landau theoretical interpretation of phase transitions in Antiferroelectrics (AFEs) materials. The results show that the phase transitions occurring in AFEs have prominently first and second order properties. Landau theories of first and second order phase transition have been appropriately analyzed in order to explain some of desirable phenomenological behaviors occurring in AFE materials. The spatial order parameter profile of AFE domain wall was derived and tested for possibilities of having ferroelectricity (FE) in accordance with Landau type energy functional. It was found that FE may appear but with additional system instability because of additional energy as a result of polarization gradient.

Superconducting state in a circular SQUID shaped mesoscopic film

Using a thin-film approach to the time-dependent Ginzburg–Landau theory, we have studied the magnetization and order parameter profile in a thin mesoscopic superconductor in the so-called SQUID geometry. Our sample is circular with a hole at the center connected to the outer rim by a very thin slit. We have also studied the influence of the boundary conditions in the thin slit on the magnetization curve of the sample.

Mitigation of Distortion in an Edge-Welded Bar by Optimization Control of the Welding Current and Speed Profile During Welding

Welding distortion is usually controlled by clamping techniques that can be tack welds, pre-bending, and tension loading. Side heating or fast cooling can also mitigate the distortion in some applications. In addition to the clamping techniques, process parameters affect the distortion so that if one can control the welding process parameters, an optimized profile of such parameters could alleviate the distortion. It is shown in this paper that the distortion can be mitigated by using an optimized profile of welding current and travelling speed. These profiles keep the power per unit length of welding constant. It is shown that an increasing welding current at the beginning and the end of the welding path on an edge welded bar of Aluminum could result in a bar that is closer to flat compared to the constant welding current. Developing an optimized weld process parameter profile requires a trustable computational model to implement a control problem using a predictive model for distortion in front of the weld pool in order to adjust the welding current and speed. Unlike using a constant welding current for the full path of weld, the path length is divided into several sub-paths. For each of weld sub-path the control problem learns from the previous sub-path and tries to find the new value for the welding current and speed that minimize the distortion using predictive Computational Weld Mechanics (CWM). Final deflections of the bar are also compared between a constant welding current and optimized profile of welding current.