New type of phase transition in Reissner Nordstr\"om - AdS black hole and its thermodynamic geometry

The phase transition of a RN-AdS black hole is studied in details using Ehrenfest's equations. There is no discontinuity in entropy which signals a lack of any first order phase transition. We then show that although Ehrenfest's first equation is satisfied, the second is not, so that a true second order phase transition is also ruled out. However this deviation from the second Ehrenfest's equation, for a certain range of the black hole charge, indicates the existence of a new glassy type transition. We finally study the thermodynamic behaviour using state space geometry and find that the scalar curvature diverges exactly at those points where the heat capacity diverges.Comment: Major revisions in Sec. 3. New results and interpretations. 2 new references. To appear in Phys. Lett.

Effect Of Strain Ageing In Welded And Non Welded Low Carbon Steel

Low carbon steels are susceptible to strain ageing as a result of which there is an increase in yield strength at the cost of ductility. These steels are used for structural applications, in which welding is used as a method of joining. There are certain regions away from the weldment which pass through the temperature range of 80 to 2500c during cooling after welding. Since in many of the structures like ship building these steels are welded in deformed condition thus the above said regions are subjected to straining and ageing, thus leading to strain ageing. In the present study an attempt has been made to study the effect of strain ageing in welded low carbon steel and the results are compared with those obtained after strain ageing of the same steel in the non welded condition. The parameters used were : (1) % The extent of pre-strain of pre-strain used was 6 ± 2 %.(2)The temperature of ageing used was 150 ±300c.(3)The time of ageing used was 4 ± 2 hrs. Using the method of Statistical Design Of Experiments the results were analysed to develop regression equations for welded as well as non welded steels. The equations developed are shown in eqn(1) and eqn(2) respectively. For non welded: ΔY = 24.04 - 2.18X1 + 4.9 X2 + 1.4 X3 – 0.03X1X2 – 0.018X1X3 + 35X2X3 - 0.28X1X2X

Generalised Uncertainty Principle, Remnant Mass and Singularity Problem in Black Hole Thermodynamics

We have derived a new Generalised Uncertainty Principle (GUP) based on certain general assumptions. This GUP is consistent with predictions from string theory. It is then used to study Schwarzschild black hole thermodynamics. Corrections to the mass-temperature relation, area law and heat capacity are obtained. We find that the evaporation process stops at a particular mass, referred as the remnant mass. This is instrumental in bypassing the well known singularity problem that occurs in a semiclassical approach.Comment: Minor changes, to appear in Phys. Lett.

Computer simulation of cavity filling during injection molding process

A numerical technique is proposed for the simulation of cavity filling process during injection molding of glass-bead filled polypropylene. The mold cavity is of cylindrical shape. Marker And Cell (MAC) method is utilized for solving the transient flow phenomena, after a mathematical simulation of the flow model is carried out by using the relevant continuity and-momentum equations governing the system. The complexity of the equations involved, results in the simplifying assumption of incompressible and isothermal flow process. A computer program is written on the basis of finite-difference equations developed during the application of MAC method under the prevailing conditions. The numerical results yield significant data on the progression of the melt front, the velocity profiles in both axial and transverse directions and the pressure distributions at different times and positions in the cavity

Relating the generating functionals in field/antifield formulation through finite field dependent BRST transformation

We study the field/antifield formulation of pure Yang Mills theory in the framework of finite field dependent BRST transformation. We show that the generating functionals corresponding to different solutions of quantum master equation are connected through the finite field dependent BRST transformations. We establish this result with the help of several explicit examples.Comment: Revtex4, 18 pages, No figs, Accepted in Eur. Phys. J

A CROSS-SECTIONAL STUDY ON MENTAL HEALTH AND CARDIOVASCULAR REACTIVITY AMONG FRESH RESIDENT DOCTORS DURING COVID19 PANDEMIC IN INDIA

Objective: The adverse psychological impact in doctors battling the Corona Virus Disease 2019 (COVID 19) epidemic arise from various social and administrative issues like excessive workload, inadequate interpersonal communications, biased work culture and lack of social support thus raising a warning of the mental health in doctors. The present study was done to assess the mental health and stress reactivity among the resident doctors who have been working for a prolonged duration during covid 19 pandemic in India. Methods: The subjects included 162 young resident doctors both males and females, of age group between 25-30 y, among which 92 were posted in covid wards on a rotation basis from 1st April 2020 to 31st December 2020 and 70 were doing duty in regular non-covid wards or not had done even a single duty in covid ward during the above period. All participants completed an online questionnaire that included the Beck Anxiety Inventory (BAI), the Beck Depression Inventory (BDI)–II, Connor-Davidson resilience scale (CDRISC) and Social Support Rating Scale (SSRS) followed by a cold pressor test to assess stress reactivity. Results: There were significant differences in the mental health and stress reactivity scores with lower resilience scores, lower social support rating scores, increased anxiety and depression in Covid ward doctors (p=0.001). Conclusion: The findings suggested high levels of training, resilience helpful social support and unbiased work culture were necessary to health care workers engaged in public health emergence

Generalized Uncertainty Principle, Modified Dispersion Relation and Barrier penetration by a Dirac particle

We have studied the energy band structure of a Dirac particle in presence of a generalised uncertainty principle (GUP). We start from defining a modified momentum operator and derive corresponding modified dispersion relation (MDR) and GUP. Apart from the forbidden band within the range $\pm m$, $m$ being the mass of the particle, we find the existence of additional forbidden bands at the both ends of the spectrum. Such band structure forbids a Dirac particle to penetrate a potential step of sufficient height ($\sim E_P$, $E_P$ being Planck energy). This is also true for massless particle. Unlike the relativistic case, a massless particle also can reflect from a barrier of sufficient height. Finally we discuss about the Klein's paradox in presence of the GUP.Comment: 10 pages, 7 figures, LaTe

Experimental Study on Resistance in Gravel Bed Channels

River beds are frequently experienced by gravel beds the analysis of which is very interesting and challenging to the river engineers and researchers.Gravel bed can be categorized it into three bedload condition,i.e. no load, moderate and intense.The present study investigates the roughness characteristics of gravel bed open channel flows under both no load and intense load conditions over various discharges and flow depths.Experimental investigation has been carried out in an open channel flow with Gravel bed surface of grain size of D50 values 13.5 mm and 6.5 mm for both no load and intense load conditions respectively. Measurement for the velocity and the boundary shear stress of the gravel bed condition has been determined. The longitudinal slope of the channel is 0.25%. Hence,for the case of gravel size 13.5mm, gravel is not transported,thus a case of no load condition occurs.Whereas in the case of 6.5mm gravel size,the gravel is transported under the condition of intense load such that in the particular case the bed load transport rate has been determined.Variation of friction factor for both the roughness conditions for different flow depths has been estimated.The intensity of the bed load has also been calculated with the help of sediment transport rate. It was observed that bed load was falling with increasing grain sizes under both no load and intense load conditions. Hence,an improved model for prediction of friction factor has been devised.This model has been validated with the data set of other investigators,showing satisfactory values pertaining to the actual values of Darcy‘s f.The developed model has also been compared with the models of other researchers and is found to provide better results than those given by others.The bed load transport rate for the intense load conditions was also determined from experimentation on gravel beds of 6.5mm gravel size for different flow depths.By the use of the data set of other researchers and present experimental data,a new model to formulate intensity of the bed load transport with respect to Shield‘s parameter has been formulated.The modified model is found to provide satisfactory results as compared to previous works

Mathematical Analysis of Regression Model Epidemiology

Statistical modeling techniques, specifically regression line analysis have become important analytical tools and are contributing immensely to the field of epidemiology. However, many users do not understand their effective use and applications. Underlying epidemiological concepts and not the statistics should govern or justify the proper use and application of any modeling exercise. Main utility of the regression line analysis lies in its ability to provide a general but practical conceptual framework for casual problems, explaining and evaluating the role of biases, confounders and effect modifiers. Successful modeling of complex data is a part science, part statistics and part experience, but the major part is logic or common sense. Findings of this research article focuses on the contributions of regression analysis towards the pedagogical study of epidemiological models by enhancing the research process and serving as an effective tool for communicating findings to public health managers and policymakers and fostering interdisciplinary collaboration

Examination of Focused Beam Propagation through a Finite Non-reciprocal Planar Chiral Slab Using Complex Fresnel Coefficients and Dual Transforms

Recently, uniform plane wave propagation across a nonchiral-chiral interface was examined via the development of appropriate Fresnel coefficients. In this extension, propagation of focused uniform and profiled beams through a finite, planar nonreciprocal chiral slab is investigated using complex Fresnel coefficients via angular plane wave decomposition and dual transforms