Propagation of Free Torsional Waves in a Non Homogeneous Magneto visco Elastic Slab with a Cylindrical Hole

The aim of the present paper is to investigate the propagation of free torsional waves in a non-homogeneous magneto-visco-elastic slab with a cylindrical hole and obtain frequency equation. The shear modulus meu and the density rho of the slab are assumed to vary as some power of the radial distance

Torsional Vibration of a Non-Homogeneous Composite Cylindrical Shell Subjected to a Magnetic Field

This paper investigates the propagation of torsional wave in a non-homogeneous composite cylindrical shell characterised by an aeolotropic material in the region r/sub 1/ grater than equal r grater than equal r /sub 2/ and visco-elastic material representing a parallel union of Kelvin and Maxwell bodies in the region r/sub 2/ greater than equal r/ greater than equal r/sub 3/. The non-homogeneity of the shell is due to the variable elastic constants C/sub i/ sub j/, variable density p and variable shear modulus p. Lastly, frequency equation and phase velocity of the wave have been calculated. The perturbation equations of the field the torsional vibration of aeolotropic as well as visco-elastic shell have also been investigated

Magneto-Elastic Rayleigh Waves on the Surface of Orthotropic Cylinder of Varying Density

This paper studies magneto-elastic Rayleigh waves on the surface of orthotropic cylinder of varying density. Solving three dimensional magneto-elastic equations frequency equations for axial waves are derived

Radial Vibration of an Aeolotropic Cylindrical Shell of Varying Density in a Magnetic Field

In this paper, we have discussed the problem of vibration of cylindrical shell of aelotropic material of variable density for two different cases- first, when the density varies linearly and second, when it varies inversely as the radius vecto

Magneto Elastic Torsional Waves in a Composite Non Homogeneous Cylindrical Shell Under Initial Stress

This paper investigates magneto-elastic torsional waves in a composite non homogeneous cylindrical shell under initial stress. The non homogeneous character of the shell is due to the variable elastic constants C/sub ij/ and the variable density rho. The composite form of the shell is due to the combination of orthotropic elastic material and visco-elastic material of general linear type. Frequency equation for the said wave has been derived

Magnetoelastic Torsional Vibration of Non-homogeneous Aeolotropic Cylindrical Shell of Viscoelastic Solids

This study investigates magnetoelastic torsional vibration of a non-homogeneous aeolotropic cylindrical shell of viscoelastic solids. The non-homogeneity of the shell obeyingpower law variation of elastic constants and density given by Aij= Crjf', p = por"(i, j = 1,2 ,... 6), where Cu (i, j = 1,2, ... 6) and po are constants and r is the radius vector. Frequency equation and phase velocity in several cases have been derived. Such problems of interaction of elastic  and electromagnetic fields have numerous applications in various branches of science, particularly in the detection of mechanical explosions in the interior of the earth and in the electromagnetic energy into vacuum

Prevalence of psychiatric co morbidities in bronchial asthma and chronic obstructive pulmonary disease patients in north Indian population cohort

Background: Psychiatric co morbidities tend to occur quite frequently in patients of chronic respiratory diseases mainly bronchial asthma and Chronic Obstructive Pulmonary Disease (COPD) but still it is highly under diagnosed. Aim and objective of the study was to find out the prevalence of psychiatric co morbidities in asthma and COPD and to correlate them with disease severity according to Global Initiative against Obstructive Lung Disease (GOLD) and Global Initiative against Asthma (GINA) guidelines.Methods: Study was conducted in Department of TB and Chest in association with Department of Psychiatry of Punjab Institute of Medical Sciences, a secondary care medical college in north India. A total 204 patients, 68 of bronchial asthma, 68 0f COPD and 68 were controls included in the study. Diagnosis and severity of respiratory diseases was assessed by spirometry. Evaluation of psychiatric co morbidities was done using the MINI international neuropsychiatric interview questionnaire.Results: The frequency of psychiatric co morbidities in COPD patients was significantly higher (32.4%) compared to patients of bronchial asthma (20.6%). The most common co morbidity in both arms was generalized anxiety disorder (17.6% in COPD patients and 10.3% in patients of bronchial asthma.Conclusions: COPD patients have a higher frequency of psychiatric co morbidities compared to bronchial asthma patients and control population. These should be properly screened and treated.

Critical reflections on asymptotically safe gravity

Asymptotic safety is a theoretical proposal for the ultraviolet completion of quantum field theories, in particular for quantum gravity. Significant progress on this program has led to a first characterization of the Reuter fixed point. Further advancement in our understanding of the nature of quantumspacetime requires addressing a number of open questions and challenges. Here, we aim at providing a critical reflection on the state of the art in the asymptotic safety program, specifying and elaborating on open questions of both technical and conceptual nature. We also point out systematic pathways, in various stages of practical implementation, toward answering them. Finally, we also take the opportunity to clarify some common misunderstandings regarding the program

Erratum: Global, regional, and national comparative risk assessment of 84 behavioural, environmental and occupational, and metabolic risks or clusters of risks for 195 countries and territories, 1990–2017: a systematic analysis for the Global Burden of Disease Study 2017

Interpretation: By quantifying levels and trends in exposures to risk factors and the resulting disease burden, this assessment offers insight into where past policy and programme efforts might have been successful and highlights current priorities for public health action. Decreases in behavioural, environmental, and occupational risks have largely offset the effects of population growth and ageing, in relation to trends in absolute burden. Conversely, the combination of increasing metabolic risks and population ageing will probably continue to drive the increasing trends in non-communicable diseases at the global level, which presents both a public health challenge and opportunity. We see considerable spatiotemporal heterogeneity in levels of risk exposure and risk-attributable burden. Although levels of development underlie some of this heterogeneity, O/E ratios show risks for which countries are overperforming or underperforming relative to their level of development. As such, these ratios provide a benchmarking tool to help to focus local decision making. Our findings reinforce the importance of both risk exposure monitoring and epidemiological research to assess causal connections between risks and health outcomes, and they highlight the usefulness of the GBD study in synthesising data to draw comprehensive and robust conclusions that help to inform good policy and strategic health planning

Global, regional, and national comparative risk assessment of 84 behavioural, environmental and occupational, and metabolic risks or clusters of risks for 195 countries and territories, 1990-2017: a systematic analysis for the Global Burden of Disease Study 2017

Background The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2017 comparative risk assessment (CRA) is a comprehensive approach to risk factor quantification that offers a useful tool for synthesising evidence on risks and risk–outcome associations. With each annual GBD study, we update the GBD CRA to incorporate improved methods, new risks and risk–outcome pairs, and new data on risk exposure levels and risk–outcome associations. Methods We used the CRA framework developed for previous iterations of GBD to estimate levels and trends in exposure, attributable deaths, and attributable disability-adjusted life-years (DALYs), by age group, sex, year, and location for 84 behavioural, environmental and occupational, and metabolic risks or groups of risks from 1990 to 2017. This study included 476 risk–outcome pairs that met the GBD study criteria for convincing or probable evidence of causation. We extracted relative risk and exposure estimates from 46 749 randomised controlled trials, cohort studies, household surveys, census data, satellite data, and other sources. We used statistical models to pool data, adjust for bias, and incorporate covariates. Using the counterfactual scenario of theoretical minimum risk exposure level (TMREL), we estimated the portion of deaths and DALYs that could be attributed to a given risk. We explored the relationship between development and risk exposure by modelling the relationship between the Socio-demographic Index (SDI) and risk-weighted exposure prevalence and estimated expected levels of exposure and risk-attributable burden by SDI. Finally, we explored temporal changes in risk-attributable DALYs by decomposing those changes into six main component drivers of change as follows: (1) population growth; (2) changes in population age structures; (3) changes in exposure to environmental and occupational risks; (4) changes in exposure to behavioural risks; (5) changes in exposure to metabolic risks; and (6) changes due to all other factors, approximated as the risk-deleted death and DALY rates, where the risk-deleted rate is the rate that would be observed had we reduced the exposure levels to the TMREL for all risk factors included in GBD 2017. Findings In 2017, 34·1 million (95% uncertainty interval [UI] 33·3–35·0) deaths and 1·21 billion (1·14–1·28) DALYs were attributable to GBD risk factors. Globally, 61·0% (59·6–62·4) of deaths and 48·3% (46·3–50·2) of DALYs were attributed to the GBD 2017 risk factors. When ranked by risk-attributable DALYs, high systolic blood pressure (SBP) was the leading risk factor, accounting for 10·4 million (9·39–11·5) deaths and 218 million (198–237) DALYs, followed by smoking (7·10 million [6·83–7·37] deaths and 182 million [173–193] DALYs), high fasting plasma glucose (6·53 million [5·23–8·23] deaths and 171 million [144–201] DALYs), high body-mass index (BMI; 4·72 million [2·99–6·70] deaths and 148 million [98·6–202] DALYs), and short gestation for birthweight (1·43 million [1·36–1·51] deaths and 139 million [131–147] DALYs). In total, risk-attributable DALYs declined by 4·9% (3·3–6·5) between 2007 and 2017. In the absence of demographic changes (ie, population growth and ageing), changes in risk exposure and risk-deleted DALYs would have led to a 23·5% decline in DALYs during that period. Conversely, in the absence of changes in risk exposure and risk-deleted DALYs, demographic changes would have led to an 18·6% increase in DALYs during that period. The ratios of observed risk exposure levels to exposure levels expected based on SDI (O/E ratios) increased globally for unsafe drinking water and household air pollution between 1990 and 2017. This result suggests that development is occurring more rapidly than are changes in the underlying risk structure in a population. Conversely, nearly universal declines in O/E ratios for smoking and alcohol use indicate that, for a given SDI, exposure to these risks is declining. In 2017, the leading Level 4 risk factor for age-standardised DALY rates was high SBP in four super-regions: central Europe, eastern Europe, and central Asia; north Africa and Middle East; south Asia; and southeast Asia, east Asia, and Oceania. The leading risk factor in the high-income super-region was smoking, in Latin America and Caribbean was high BMI, and in sub-Saharan Africa was unsafe sex. O/E ratios for unsafe sex in sub-Saharan Africa were notably high, and those for alcohol use in north Africa and the Middle East were notably low. Interpretation By quantifying levels and trends in exposures to risk factors and the resulting disease burden, this assessment offers insight into where past policy and programme efforts might have been successful and highlights current priorities for public health action. Decreases in behavioural, environmental, and occupational risks have largely offset the effects of population growth and ageing, in relation to trends in absolute burden. Conversely, the combination of increasing metabolic risks and population ageing will probably continue to drive the increasing trends in non-communicable diseases at the global level, which presents both a public health challenge and opportunity. We see considerable spatiotemporal heterogeneity in levels of risk exposure and risk-attributable burden. Although levels of development underlie some of this heterogeneity, O/E ratios show risks for which countries are overperforming or underperforming relative to their level of development. As such, these ratios provide a benchmarking tool to help to focus local decision making. Our findings reinforce the importance of both risk exposure monitoring and epidemiological research to assess causal connections between risks and health outcomes, and they highlight the usefulness of the GBD study in synthesising data to draw comprehensive and robust conclusions that help to inform good policy and strategic health planning