Unsteady Fluid Flow and Heat Transfer Through a Porous Medium in a Horizontal Channel with an Inclined Magnetic Field

This paper investigates the unsteady flow and heat transfer of a viscous, incompressible, and electrically conducting fluid through a porous medium in a horizontal channel. The basic physical properties of the fluid and the porous medium are constant. The fluids considered are those with the Prandtl number less than 1. The channel walls are made of horizontal permeable plates, which are at constant but different temperatures. Fluid suction/injection through the plates occurs at a velocity perpendicular to the plates, whose intensity is a cosine function of time. The applied external magnetic field is homogeneous and inclined in relation to the transverse plane of the channel. The problem is dealt with through an inductionless approximation. Fluid flow is instigated by constant pressure drops along the channel. The equations used to describe the problem are transformed to dimensionless forms and solved analytically using the perturbation method. Approximate analytical expressions for dimensionless fluid flow velocity and dimensionless temperature are determined as functions of the following physical parameters: Prandtl number, Hartmann number, porosity factor, frequency, amplitude, and magnetic field inclination angle. Numerical results are presented as diagrams and tables and are used to analyse the influence of physical parameters on the fluid flow velocity and temperature

Mathematical Modeling of Heat Transfer of Liquefied Natural Gas Engines

The article presents a mathematical model for pressure growth in the line supplying the engine KAMAZ with cryogenic fuel under specific insulation conditions. By using the heat balance equation the model in a simple linear form is obtained. This makes the model suitable for use in solving practical tasks related to the design of a liquefied natural gas engine fuel system. According to the above-mentioned method, the geometric parameters of the section of the main elements are determined under different external conditions and the boundary parameters of the gas fuel (maximum and minimum values of pressure, temperature, and flow). These data are necessary to determine the consumption, hydraulic and project features of the project. Fuel pipes are optimized (for hydraulic resistance, pressure and flow impulses, structural strength) to improve the accuracy of fuel dosing. The adequacy of the model was tested on a special modified test stand

VALVE SELECTION FOR THE PURPOSE OF REDUCING THE WATER HAMMER EFFECT IN A PRESSURIZED PIPELINE

This paper discusses the gravity-fed hydraulic system, which consists of the upper reservoir, the lower reservoir, the pipeline, and valves. To achieve simpler and more efficient protection of a system against water hammer, it is advisable to establish conditions in which the pressure rises as little as possible during transient regimes without using any protective equipment. The discussion focuses on the pressure rise caused by different valve types: butterfly, needle, and ball valves, as well as two valve closure intervals – 20 and 40 seconds. The systems considered have nominal diameters of DN 300 and DN 600. The problem was studied using a simulation of unsteady flow regimes of hydraulic transport. The obtained results regarding the maximum pressure rise due to water hammer were used to select the most satisfactory control valve for the considered hydraulic system

Validation of the ELISA Method for Quantitative Detection of TNF-α in Patients with Intracerebral Hemorrhage

AIM: We aimed to investigate the sensitivity, reproducibility and validity of the commercial ELISA kits for quantitative detection of TNF-α and their potential application for screening purposes in patients with ICH.METHODS: Analysis of six independent standard series, evaluation of the deviation of the TNF-α concentration in patients with ICH, standard addition and visual analysis of whole UV-Vis spectra were carefully performed.RESULTS: Low standard deviations of the absorbance were detected for every standard, as well as in the samples of healthy controls and patients with ICH. The standard addition series have also confirmed high sensitivity and reproducibility of the assay, with a congruent shift of the standard curves with the concentration of TNF-α for the added plasma. The visual analyses of the gained spectra have revealed the absence of any matrix effects from the addition of the human plasma in the reconstituted standards.CONCLUSION: The commercial ELISA kits can be used in the clinical practice for screening purposes of the plasma TNF-α levels in patients with ICH

Pulmonary O-methyl transferases

An investigation in vitro of pulmonary O-methyl transferases revealed the presence of microsomal phenol-O-methyl transferase and soluble and microsomal catechol-O-methyl transferases in guineapig lung tissue. Both phenol and catechol transferases also were detected in rat and rabbit lung tissue. Substrates of guinea-pig pulmonary phenol-O-methyl transferase included phenols, cresols and xylenols. but not alcohols and amines. Catechol-O-methyl transferases from both subcellular sources were found to have similar pH optima, magnesium ion requirements, Km values, and utilized norepinephrine, isoproterenol and dopamine as substrates, but not metaproterenol and salbutamol. These data for the pulmonary enzymes are similar to published values for liver O-methyl transferases.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/22141/1/0000570.pd

Careers in context: An international study of career goals as mesostructure between societies' career-related human potential and proactive career behaviour

Careers exist in a societal context that offers both constraints and opportunities for career actors. Whereas most studies focus on proximal individual and/or organisational-level variables, we provide insights into how career goals and behaviours are understood and embedded in the more distal societal context. More specifically, we operationalise societal context using the career-related human potential composite and aim to understand if and why career goals and behaviours vary between countries. Drawing on a model of career structuration and using multilevel mediation modelling, we draw on a survey of 17,986 employees from 27 countries, covering nine of GLOBE's 10 cultural clusters, and national statistical data to examine the relationship between societal context (macrostructure building the career-opportunity structure) and actors' career goals (career mesostructure) and career behaviour (actions). We show that societal context in terms of societies' career-related human potential composite is negatively associated with the importance given to financial achievements as a specific career mesostructure in a society that is positively related to individuals' proactive career behaviour. Our career mesostructure fully mediates the relationship between societal context and individuals' proactive career behaviour. In this way, we expand career theory's scope beyond occupation- and organisation-related factors

A single-subject evaluation of the treatment of morphing fear

We present a single-subject prospective outcome study of a man with severe morphing fear and long history of OCD who was not helped by previous interventions, and who received an adapted form of cognitive behavior therapy (CBT) as part of this study. Treatment consisted of a cognitively focused approach tailored to address his fear of morphing and included developing a stronger sense of self-stability. We describe the details of the case, the treatment protocol, and the therapeutic outcomes as assessed over 36 weeks by questionnaires, rating scales, and semistructured interviews. The intervention was effective in eradicating the patient’s morphing fears and reducing other symptoms of OCD, anxiety, and depression. The presented case illustrates the need to appropriately conceptualize, assess, and address the specific nature of morphing fear symptoms in treatment