Simulation of the thermodynamic structure of atmospheric boundary layer over Calcutta with a one-dimensional TKE closure PBL model

The thermodynamic structure of boundary la)l:r over Calcutta on the eastern secto r of the monsoontrough has been exam ined byint~ratina I one-dimensional TKE closure planetary bound ary laye r model fortropics which inJcudes interaction oCclo udiness and radiation with turbulence and counter , radient transports ofheal moistu re and momentum. Data sets cf pilct-esperiment phase ofMONTBLEX in 1988 have been used formispurpo se. two specific situations, o ne 'When liquid water is present and the other ~tlcn very strona: winds are prevailinain the boundary layer 8~ considered. Diurn al varialion oCturbulent kinetic ener'ly.lhe TKE budget and the veelicalprofiles otTKE and eddy exchange coefficient ha ve revealed the importance DC counter gradient transports notonly aCheat and moisture but also oC momentum. Combined role DC presence of liquid water and counter gradientsin buoyant production and role of counter a:radienu of momentum in shear production have beenestablished.

Vertical turbulent exchange structure and parametrization for 3D shallow water hydrodynamics models

The work describes research of vertical turbulent exchange structure and parametrization for 3D shallow water hydrodynamics models. In this paper, the coefficients of horizontal turbulent exchange are calculated using a whole set of averaging periods of turbulent velocity pulsations. Using experimental data on the pulsations of the velocity components, the coefficient of vertical turbulent exchange was calculated on the basis of various approaches to its parameterization, based on the analysis of the obtained coefficient distributions, the most adequate parameterization of the coefficient was selected, which is used in the software package. The distribution of the vertical turbulent exchange coefficient obtained in a numerical experiment was compared with the results of full-scale measurements, and the calculation results obtained using the mathematical statistics apparatus were analysed.

Client, provider, and visit factors associated with quality in contraceptive counseling in Mexico: an exploratory cross-sectional analysis

Background Monitoring clients’ experiences with contraceptive care is vital to inform quality improvement efforts and ensure fulfillment of individuals’ human rights. The Quality of Contraceptive Counseling (QCC) Scale is a previously validated scale that comprehensively measures individuals’ experiences receiving counseling in three subscales: Information Exchange, Interpersonal Relationship, and Disrespect and Abuse. We sought to better understand the correlation of client, provider, and visit factors with client-reported quality of contraceptive counseling in the public sector in two Mexican states using the QCC Scale. Methods This cross-sectional survey study used the QCC Scale total score and subscale scores as outcome variables. Explanatory variables included clients’ age, LGBTTTIQ status, relationship status, number of children, education, and occupation; providers’ gender and type of provider; and the reason for visit. Linear and logistic regression models assessed bivariate associations. Multivariable, multilevel mixed-effects models with clinic as a random effect were fit. All models used complete cases (n = 470). Results In the multilevel mixed-effects analyses, patients aged 35+ years reported worse Information Exchange (coefficient − 0.29, p = 0.01). Clients receiving care post-partum reported worse Information Exchange (coefficient − 0.25, p = 0.02) and worse total scores (coefficient − 0.15, p = 0.04) compared to clients seeking contraceptive information or methods. Clients who had 1+ children reported better Information Exchange (coefficient 0.21, p = 0.01) than those with no children. Though Disrespect and Abuse subscale scores were overall high (indicating high quality of care), we found a significant association between age and report of such negative experiences: clients in increasing age categories had increasingly higher adjusted odds of reporting no disrespect and abuse (aORs compared to the youngest group were 2.50 for those aged 19–24 years, p = 0.04; 4.53 for those 25–34 years, p = 0.01; and 6.11 for those 35+ years, p = 0.01.) Conclusions Our findings align with previous results that younger clients have lower adjusted odds of reporting high-quality services in Mexico. There is a need for continued work supporting youth-friendly services in Mexico, and efforts should aim to ensure zero tolerance for disrespectful or coercive provider behaviors, such as pressuring or scolding clients. Improvements are also needed to ensure quality in counseling for post-partum clients, those aged 35+ years, and those without children.

Performance Evaluation of Thermal Attributes in Impinging Jet Heat Sink using Airfoil Pillars with and without Nano Fluid

Objectives: In the current research three techniques have been operated to enhance the rate of heat transfer in a heat sink. The amalgamation of Impingement of jet, airfoil pillars and Nano fluids are used. Nano fluids has a lot of potential to enhance the heat transportation in contrast to the water. The investigation has been executed with the help of three dimensional numerical model using Computational fluid Dynamics. At the onset the model has been validated with the inspection carried out already in experimental form. The observations in the form of thermal attributes are investigated. From the results the conclusion is made that the use of airfoil pillars and Nano fluids has increased the thermal characteristics of the three dimensional model in the form of heat exchange coefficient by almost 28.2%. The Nano fluid has been utilized for the 0.5% concentration.

Enhancement of Convection Heat Transfer in Air Using Ultrasound

The use of ultrasound is a new method to enhance convection drying. However, there is little information in the literature on the improvement of convective heat transfer caused by ultrasound. Therefore, the heat transport during ultrasound-assisted convective heating of small samples in a hybrid dryer was experimentally examined. A small Biot number regime of heat transfer was considered. The results confirmed a great enhancement of heat transfer due to the application of ultrasound. Due to the use of ultrasound, the convective heat exchange coefficient increased from 45% to almost 250%. The enhancement is a linear function of applied ultrasound power. It was shown that the energy absorption of ultrasound existed, but the thermal effect of this absorption was very small.

Method for Determining the Optimum Insulation Thickness of the Plaster Tow Material: Influence of the Heat Exchange Coefficient in Transient Regime

In this paper, we have applied a numerical method to determine the optimum insulation thickness of the tow plaster plane material. The influence of the exchange coefficients at the level of the two faces of the material has been highlighted. The optimum insulation thickness of the material is at the area where the thermal resistance value of the material is the maximum. We added the relative thermal resistance to show how the optimum insulation thickness changes when the exchange coefficients change values.

Basic Regularities of Vertical Turbulent Exchange in the Mixed and Stratified Layers of the Black Sea

Purpose. The purpose of the study is to assess the coefficient of vertical turbulent exchange for different layers of the Black Sea basin based on the experimental data on microstructure of the physical fields obtained for the period 2004–2019 in the Black Sea and using the semi-empirical models. Methods and Results. For the upper mixed layer, the turbulent energy dissipation rate ɛ and the exchange coefficient were calculated using the velocity fluctuation spectra based on the Kolmogorov hypotheses on the turbulence spectrum inertial range. In the stratified layers, the turbulence coefficient and the dissipation rate were experimentally determined both from the spectra of the velocity horizontal fluctuations’ gradients and the vertical spectra of temperature fluctuations using the concept of the effective scale of turbulent patches. Depending on the features of the hydrological regime and the prevailing energy contributors to turbulence generation, five layers were identified and described (including their characteristic power dependences of the vertical turbulent diffusion coefficients K on the buoyancy frequency N) using the 1.5D-model of vertical turbulent exchange for the basin under study. For the stratified layers, the 1.5D-model results were comparatively analyzed with those of the other semi-empirical and theoretical models describing the most probable hydrophysical processes in each specific layer; the relations for the vertical turbulent exchange coefficient were obtained depending on the buoyancy frequency. Conclusions. Comparison of the experimental data collected under different hydrometeorological conditions with the simulations resulted from the known turbulence models for the sea upper layer showed that the best agreement between the simulation and measurement data was provided by a multiscale model taking into account three basic mechanisms of turbulence generation: current velocity shear, instability of wave motions, and wave breaking. The turbulent exchange coefficient dependencies on depth are conditioned by the effect of the turbulence dominant source at a given level. In the stratified layers, the exchange coefficient dependence on buoyancy frequency is determined by the hydrophysical processes in each layer; the relations obtained for individual layers indicate intensity of the contributions of vertical advection, internal wave breakings, turbulence diffusion and geothermal flux.

Basic Regularities of Vertical Turbulent Exchange in the Mixed and Stratified Layers of the Black Sea

Purpose. The purpose of the study is to assess the coefficient of vertical turbulent exchange for different layers of the Black Sea basin based on the experimental data on microstructure of the physical fields obtained for the period 2004–2019 in the Black Sea and using the semi-empirical models. Methods and Results. For the upper mixed layer, the turbulent energy dissipation rate ɛ and the exchange coefficient were calculated using the velocity fluctuation spectra based on the Kolmogorov hypotheses on the turbulence spectrum inertial range. In the stratified layers, the turbulence coefficient and the dissipation rate were experimentally determined both from the spectra of the velocity horizontal fluctuations’ gradients and the vertical spectra of temperature fluctuations using the concept of the effective scale of turbulent spots. Depending on the features of the hydrological regime and the prevailing energy contributors to turbulence generation, five layers were identified and described (including their characteristic power dependences of the vertical turbulent diffusion coefficients K on the buoyancy frequency N) using the 1.5D-model of vertical turbulent exchange for the basin under study. For the stratified layers, the 1.5D-model results were comparatively analyzed with those of the other semi-empirical and theoretical models describing the most probable hydrophysical processes in each specific layer; the relations for the vertical turbulent exchange coefficient were obtained depending on the buoyancy frequency. Conclusions. Comparison of the experimental data collected under different hydrometeorological conditions with the simulations resulted from the known turbulence models for the sea upper layer showed that the best agreement between the simulation and measurement data was provided by a multiscale model taking into account three basic mechanisms of turbulence generation: current velocity shear, instability of wave motions, and wave breaking. The turbulent exchange coefficient dependencies on depth are conditioned by the affect of the turbulence dominant source at a given level. In the stratified layers, the exchange coefficient dependence on buoyancy frequency is determined by the hydrophysical processes in each layer; the relations obtained for individual layers indicate intensity of the contributions of vertical advection, internal wave breakings, turbulence diffusion and geothermal flux.

VERTICAL TURBULENT EXCHANGE COEFFICIENT PARAMETRIZATION IN THE FRAMEWORK OF THE LES APPROACH

The vertical turbulent exchange coefficient parametrization based on the LES approach is constructed in this paper. To implement this approach, water flow velocities pulsations full-scale data at some points of shallow-water systems obtained using an acoustic Doppler flow meter (ADCP) during expedition studies were filtered using two-stage Kalman algorithm, and then averaged, after which the LES approach was applied using subgrid turbulence model. The parametrization of the coefficient of vertical turbulent exchange is used in the wave hydrodynamics mathematical model.