Function Of Pr Research Articles

Microscale heat transfer and phase change mechanisms of carbon dioxide at near-critical conditions

Recent studies highlight the potential benefits of two-phase carbon dioxide (CO2) systems operating near their thermodynamic critical point. Significant heat transfer coefficients and resistance to critical heat flux from improved vapor phase properties can enable heat transfer and reliability enhancements. However, the physical mechanisms of phase change that govern heat transfer behavior in the near-critical regime of reduced pressures (0.85<PR<1, where PR=P/Pcrit) are not well understood. In the present study, subcooled microscale (hydraulic diameter, Dh=500μm) flow boiling experiments are conducted to elucidate the heat transfer behavior near the critical point and the underlying mechanisms that influence it. Experimental data reveals a deviation from the trends predicted by the Cheng correlation (Cheng, L et al., 2008, “New prediction methods for CO2 evaporation inside tubes: Part II—An updated general flow boiling heat transfer model based on flow patterns.” Int. J. Heat Mass Transfer), in particular, displaying a decreasing peak heat transfer coefficient as pressure increases. Heat transfer in the near-critical regime can be further partitioned into two regions: near-critical boiling (0.85<PR<0.96) that exhibits heat transfer highly dependent on surface temperature, and supercritical-like behavior (0.96<PR<1) exhibiting a strong heat transfer dependence on mass flux. High-speed side-view flow visualization reveals the dominant nucleation mechanism (heterogeneous or homogeneous) governs the heat transfer behavior and is adequately predicted using flow inlet conditions. The present study provides a method for predicting nucleation behavior, which, in turn, facilitates the prediction of heat transfer near the critical point. The continuous alteration of heat transfer in the near-critical regime as a function of PR is underscored by this mechanistic insight, bridging the gap between typical flow boiling (PR<0.85) and supercritical heat transfer (PR>1).

Exact solution for heat transfer across the Sakiadis boundary layer

We consider the problem of convective heat transfer across the laminar boundary layer induced by an isothermal moving surface in a Newtonian fluid. In a previous work [Barlow et al., “Exact and explicit analytical solution for the Sakiadis boundary layer,” Phys. Fluids 36, 031703 (2024)], an exact power series solution was provided for the hydrodynamic flow, often referred to as the Sakiadis boundary layer. Here, we utilize this expression to develop an exact solution for the associated thermal boundary layer as characterized by the Prandtl number (Pr) and local Reynolds number along the surface. To extract the location-dependent heat transfer coefficient (expressed in dimensionless form as the Nusselt number), the dimensionless temperature gradient at the wall is required; this gradient is solely a function of Pr and is expressed as an integral of the exact boundary layer flow solution. We find that the exact solution for the temperature gradient is computationally unstable at large Pr, and a large Pr expansion for the temperature gradient is obtained using Laplace's method. A composite solution is obtained, which is accurate to O(10−10). Although divergent, the classical power series solution for the Sakiadis boundary layer—expanded about the wall—may be used to obtain all higher-order corrections in the asymptotic expansion. We show that this result is connected to the physics of large Prandtl number flows where the thickness of the hydrodynamic boundary layer is much larger than that of the thermal boundary layer. The present model is valid for all Prandtl numbers and attractive for ease of use.

Implementation of Excellence Public Relations and Coordinated Management of Meaning in the Socialization of the Four Main Pillars of SABar School Banyumas

SABar School (Sekolah Alam Baturraden) applies four main pillars namely the pillars of morals, logic, leadership, and entrepreneurship in the student learning process. However, the view of the Banyumas community is that SABar School is only a school that involves more playing than learning activities. Parents are worried that sending their children to SABar School will be left behind in academics. This research aims to analyze the implementation of excellence in public relations and coordinated management of meaning towards the socialization of the four main pillars of SABar School. This research uses a qualitative descriptive research method with data collection techniques of observation and in-depth interviews with ten informants, supported by secondary data through literature studies. The research shows that SABar School's role in socializing activities on the four main pillars implements eight of the ten premises of public relations excellence. Two premises that have not been implemented are the integration premise because SABar School does not yet have a dedicated PR division and the independence premise. The management function of PR is still one with other management. Meanwhile, the results of coordinated management of meaning on the four main pillars show that SABar School has achieved a level of coordination.

THE EXTERNAL FUNCTION OF AUTOMOTIVE COMPANY PUBLIC RELATIONS IN BUILDING A POSITIVE IMAGE OF THE COMPANY (Analysis of Customer Relations Division of PT. Indomobil Trada Nasional / NISSAN in Serving Customers)

A company needs communication between companies with other companies and communication with its customers so that there is harmony and harmony and in order to create a good interaction for superiors, subordinates and customers, every company needs Public Relations which can mediate between the company and the consumers. One of the reasons for the existence and need for PR in a company is the presence of competitors and high innovation, one of which is in the automotive world. It is these competitors who make the presence of PR very necessary in fostering quality communication, both internally and externally. Of course the presence of PR must also provide fresh air for the company, not just communicating and establishing relationships, but how are the PR efforts and strategies in carrying out their functions. Providing excellent service and promotion is part of PR in communication. Competitors such as Toyota, Mazda, Mitsubishi, Honda, Kia, Mercy, Suzuki, and other automotive companies are of course increasingly paying attention to customer service, making people smarter in choosing vehicle brands (trade). This is the background of the existence of PR is very necessary in a company. One, the external function of PR is to create good excellent service, increase customer satisfaction, foster a sense of loyalty to return to buy products and enjoy the services provided and of course customers who are loyal to our products, will promote to those closest to them that the company's products and services better quality than other automotive companies. PT. Indomobil Trada Nasional (NISSAN) is present in the midst of society to accompany and serve consumers.

Gromov-Witten invariants of 𝑆𝑦𝑚^{𝑑}ℙ^{𝕣}

We give a graph-sum algorithm that expresses any genus- g g Gromov-Witten invariant of the symmetric product orbifold Sym d ⁡ P r ≔ \operatorname {Sym}^d\mathbb {P}^r≔ [ ( P r ) d / S d ] [(\mathbb {P}^r)^d/S_d] in terms of “Hurwitz-Hodge integrals” – integrals over (compactified) Hurwitz spaces. We apply the algorithm to prove a mirror-type theorem for Sym d ⁡ P r \operatorname {Sym}^d\mathbb {P}^r in genus zero. The theorem states that a generating function of Gromov-Witten invariants of Sym d ⁡ P r \operatorname {Sym}^d\mathbb {P}^r is equal to an explicit power series I Sym d ⁡ P r I_{\operatorname {Sym}^d\mathbb {P}^r} , conditional upon a conjectural combinatorial identity. This is a first step in the direction of proving Ruan’s Crepant Resolution Conjecture for the resolution H i l b ( d ) ( P 2 ) Hilb^{(d)}(\mathbb {P}^2) of the coarse moduli space of Sym d ⁡ P 2 . \operatorname {Sym}^d\mathbb {P}^2.

Cinema’s Cosmic Shifts

Cinema’s Cosmic Shifts

The MHD graphene−CMC−water nanofluid past a stretchable wall with Joule heating and velocity slip impact: Coolant application

The heat transport mechanism has an engrossing application in effective heat management for the automobile industry and the biomedical industry. The analysis of the MHD graphene−carboxymethyl cellulose (CMC) solution−water nanofluid past a stretchable wall with Joule heating and velocity slip impact is performed in this regard. A graphene-based nanofluid is considered. The dynamic model is used to simplify the complicated ordinary differential equations into non-dimensional forms, which are then evaluated analytically. Numerical data and graphs are produced to analyze the consequences of a physical entity with the aid of Maple 17. Moreover, the velocity field is decreased, while the magnitude of the magnetic parameter is increased. A decrease in θ(η) is observed as a result of an increase in ϕ. It is noted that a rise in the magnetic parameter causes a fall in the temperature distribution. It is perceived that −f′′(0) is decreased with an augmentation in βs, and an opposite trend is shown for ϕ. The velocity profile is the growing function of Mgn, βs, and Kve, with the reversed mode shown in case of ϕ. The temperature profile is the declining function of Pr, Ecrt, ϕ, and χ, with a contradictory trend observed for Mgn and βs. The flow regime is displayed against the viscoelastic parameter.

Социальная мобильность и конкурс «Лидеры России»

Introduction: the collapse of the Soviet Union had a destructive effect on social mobility: the boundaries of social classes were blurred, and new social elevators were not created. This problem was particularly acute for the upper ruling class, which was left without working tools for personnel search and training, and for the society having lack of understanding of the selection and promotion to the top principles. Since the 2000s, the government has been actively working to institutionalize new mobility channels. However, their closed and non-transparent nature did not fully address the problems. Awareness of these limitations brought to life a new mechanism of social mobility – “The Leaders of Russia” competition. Objectives: to assess the role of “The Leaders of Russia” competition as a channel for vertical social mobility. We presume to address the question: is “The Leaders of Russia” an effective social elevator or is it primarily aimed at creating an image of equal and open opportunities that legitimizes political career advancement? Methods: a sociological biographical analysis of information on 313 winners of the competition (2017–2020). Results: the research covered the data on the further career advancement of competition winners; the competition’s role in expanding the social recruitment pool of the political elite, rejuvenating it, and overcoming gender asymmetry. Conclusions: “The Leaders of Russia” competition acts as a significant social elevator in contemporary Russian society and provides processes of vertical social mobility. But it should be noted that this does not apply to all the competition winners, as many of them do not get political appointments and career development. At the same time, winning the competition provides upward social movements for representatives of large state corporations or people already in public service who are possibly enjoying the different kind of support or driving forces that are not obvious. These factors may indicate the nominal openness of the competition and the leading role of its PR function.

Effect of transverse magnetic field on wake dynamics and heat transfer through a porous circular cylinder

AbstractA two‐dimensional numerical simulation using the commercial computational fluid dynamics package ANSYS Fluent 15.0 is performed to investigate the effect of a transverse magnetic field on the wake dynamics around a heated porous circular cylinder. The study is conducted considering a Newtonian, incompressible, and electrically conductive fluid with constant properties for the low Reynolds number laminar regime. In the range of Reynolds number (Re = 10–40), recirculating vortices are observed to penetrate (or detach) into (from) the porous cylinder surface depending on the Darcy number, Da (10−6 to 10−2). The effect of the magnetic field parameter (Hartmann number) Ha (0–10) on the detachment and penetration characteristics of a porous cylinder is reported for the first time. A steady separated flow behind the cylinder turns into an attached flow at a critical magnetic field strength. Accordingly, the critical Hartmann number (Hacr) is estimated for the complete suppression of the flow separation behind the porous cylinder. Hacr is found to decrease with an increase in Da and a decrease in Re. The wake behind the cylinder is also found to be detached from the cylinder surface at a particular value of the magnetic field strength termed as the detachment Hartmann number (Had). Had also decreased with an increase in Da and decrease of Re. In addition, the effect of Ha on the separation angle, recirculation length, detachment length, and drag coefficient is also discussed. Furthermore, the effect of the magnetic field on the forced convective heat transfer characteristics is also studied considering various fluids (Prandtl number, Pr = 0.02, 0.71, and 7) past the circular permeable cylinder. At a particular Pr, the heat transfer rate is almost invariant for low permeability, whereas it increases significantly at higher permeability with an applied magnetic field. The rate of heat transfer increases with the Prandtl number for all Hartmann and Darcy numbers. Finally, a correlation is developed to predict the average heat transfer as a function of Re, Pr, Da, and Ha.

Free convection boundary layer correlations for a vertical plate with nonuniform heating

An analytical study of a free convection boundary layer (BL) for a laminar and steady flow over a vertical flat plate (VFP) having nonuniform thermal conditions has been investigated. The plate is subjected to a variable wall heat flux of where is the distance along the VFP from the leading edge and is a reference heat flux. The boundary layer equations for nonuniform wall heat flux conditions have been formulated. These equations are then solved numerically for the range of exponents and Prandtl numbers () of −0.25 to 1 and 0.01 to 1000 respectively. The effects of two physical parameters and on the characteristic of thermal boundary layer (TBL) and hydrodynamic boundary layer (VBL) are described. Moreover, correlations of TBL and VBL thicknesses have been presented as a function of Pr and The TBL and VBL thickness are more influenced by Pr as compared to These correlations are reasonably accurate for uniform heat flux (n = 0) proposed by A. Bejan using a scale analysis and no other such correlations are available for nonuniform heat flux for a wide range of Prandtl numbers (Pr). It has been found that when both the BL thicknesses decrease with the Pr till a value of is reached. For the growth of VBL and TBL thickness over the VFP increases and decreases respectively. Consequently, the local skin friction coefficient decreases and the local Nusselt number increases with the increase in and at a fixed value of modified Rayleigh number.

Numerical investigation of conjugate heat transfer to a turbulent dual offset jet

The present study considers a computational model to simulate conjugate heat transfer to a turbulent dual offset jet from a heated wall having a finite thickness and subjected to a constant wall temperature. To capture the effects of turbulence on the flow and heat transfer, the Reynolds Averaged Navier–Stokes equations (RANS) with the standard k−ε turbulence model have been employed. The convection equation in the flow regime is solved together with the conduction equation in the solid medium iteratively. For the purpose of the analysis, four parameters, namely, the Reynolds number (Re), the thermal conductivity ratio of the solid material and the fluid, the solid wall thickness, and the fluid Prandtl number (Pr), are varied within suitable ranges. The flow field solution exhibits two recirculation zones; the first one is enclosed by the two jets and the other is formed underneath the lower jet. Conjugate heat transfer to the dual offset jet flow is analysed through the distribution of temperature, heat flux, and Nusselt number, at the interface between the fluid and solid regions. Results indicate that the non-dimensional temperature and heat flux profiles along the fluid–solid interface depend on all four parameters. In contrast, the distribution of the Nusselt number along the fluid–solid interface depends only on the Reynolds number and the Prandtl number. Increasing either of them leads to an overall increase in the interface Nusselt number. A correlation for the average Nusselt number along the interface is presented as a function of Re and Pr.

Peranan Pr Digital Kominfo Kabupaten Tanah Datar Dalam Publikasi Kegiatan Melalui Media Sosial

Public Relations aims to create, maintain and develop good relationships, form understanding, bridge the relationship between agencies/institutions and the public, both internally and externally. PR as a communicator from agencies/institutions must be able to be trusted by the public because PR is the first person who will deal directly with the public. Then PR as a supporter in the management function has a strategic role because it can strengthen the reputation of the agency/institution in the public eye. In the development of communication technology there is a development in the PR profession, namely what is called digital PR. Digital PR is not much different from conventional PR, which is a strategic communication process that aims to build mutually beneficial relationships between an organization and its publics. But what makes the difference is the medium of communication. While conventional PR works on events and publications in conventional media, digital PR uses more online/website technology-based media. Relations with the media are one of the functions of digital PR. Current technological developments make it easy for everyone to convey and receive news, therefore PR with its media relations function must be able to predict everything that happens in the public. Therefore, digital PR is required to be able to work with technological developments, one of which is to become digital public relations for agencies/institutions. The public will certainly find it easier to know every activity carried out by their agencies/institutions with the help of information provided by PR through publications, both from press releases, news, events and using new media as a means of disseminating online information provided to the public.

Experimental evidence for the boundary zonal flow in rotating Rayleigh–Bénard convection

We report on the presence of the boundary zonal flow in rotating Rayleigh–Bénard convection evidenced by two-dimensional particle image velocimetry. Experiments were conducted in a cylindrical cell of aspect ratio $\varGamma =D/H=1$ between its diameter ( $D$ ) and height ( $H$ ). As the working fluid, we used various mixtures of water and glycerol, leading to Prandtl numbers in the range $6.6 \lesssim \textit {Pr} \lesssim 76$ . The horizontal velocity components were measured at a horizontal cross-section at half height. The Rayleigh numbers were in the range $10^8 \leq \textit {Ra} \leq 3\times 10^9$ . The effect of rotation is quantified by the Ekman number, which was in the range $1.5\times 10^{-5}\leq \textit {Ek} \leq 1.2\times 10^{-3}$ in our experiment. With our results we show the first direct measurements of the boundary zonal flow (BZF) that develops near the sidewall and was discovered recently in numerical simulations as well as in sparse and localized temperature measurements. We analyse the thickness $\delta _0$ of the BZF as well as its maximal velocity as a function of Pr, Ra and Ek, and compare these results with previous results from direct numerical simulations.

News Reporting: Substitution of Functions

The issue of journalistic functions fulfillment by the modern mass media is considered. The authors examined a number of news reports in socio-political online media and found some cases where the classic functions of journalism such as informing and controlling were substituted by PR functions. The content analysis revealed an alarmingly large number of pseudo journalistic reports, which mainly aimed to create and maintain a positive image. The reason why journalism is losing its value is the lack of professionals representing the public interest. The analysis shown a high number of publications, based on (practically unchanged) press releases, that is common to a number of media and clearly illustrates the unprofessionalism of the authors of pseudo news. The regional media have to monetize its activity, so the matter of finance wins over the matter of beliefs. However, the media and, in particular, journalism is quickly losing public credibility. In general, we are witnessing the undermining of classical journalistic creativity and the merging of this concept with other wider categories of public relations.

Echocardiography and cardiac magnetic resonance in children with repaired tetralogy of Fallot: New insights in cardiac mechanics and exercise capacity

BackgroundPulmonary regurgitation (PR) and right ventricular (RV) dilatation and disfunction are common in patients with repaired Tetralogy of Fallot (r-TOF). AimsTo compare Echo data with the gold standard CMR in a paediatric population of r-TOF with significant PR, to assess the reliability of standard and advanced echo parameters. In addition, to evaluate their correlation with peak oxygen consumption (VO2). Methods and resultsAll patients underwent standard echo-Doppler study, speckle tracking analysis, and CMR to assess PR and RV size and function. Thirty-six patients underwent also cardiopulmonary exercise test.Fourty-six patients (aged 13.7 ± 3.0) were included. Echo derived RV areas correlated with CMR RV volumes (p < .0001, r = 0.72). RV end-diastolic area > 21.9 cm2/m2 had a good sensitivity (83.3%) and specificity (73.5%) to identify a RV end-diastolic volume ≥ 150 ml/m2. RVEF was preserved in all patients, while TAPSE was reduced in 78.2% and RVGLS in 60.8%. Flow-reversal in pulmonary branches showed a sensitivity of 95.8% and a specificity of 59.1% to identify CMR pulmonary regurgitant fraction (RF) ≥ 35%. None of the CMR parameters correlated with peak VO2. Among the Echo data only right atrial strain (RAS) correlated with peak VO2. ConclusionIn children, flow-reversal in pulmonary branches identifies hemodynamically significant RF with a good sensitivity but poor specificity. RV area by echocardiogram is a valid first-line parameter to screen RV dilation. RV longitudinal systolic dysfunction coexists with a still preserved EF. RAS correlates strongly with peak VO2 and should be added in their follow up.

Prioritising employee-organisation relationships in non-profit organisations in Kenya: Antecedents, queries and contradictions

Although employees are the most critical of organisation publics, it is unclear whether employee-organisation relationships (EORs) in non-profit organisations (NPOs) in Kenya are prioritised. To investigate this question further, the study explored relationship antecedents in two non-profit organisations. The study was informed by relationship management theory and the symmetrical communication framework. Semi-structured, indepth interviews were carried out among 24 purposively sampled management and nonmanagement employees. The data was manually analysed and requisite a priori and in vivo codes and themes identified. The study findings suggest a lack of understanding about the strategic role of public relations in the organisation. Further, technician oriented PRdepartments mediate the perceptions of and effort expended on internal relationships. Managing employee-organisation relationships was perceived more as a human resource rather than a PR function which precludes more robust forms of PR practice. The researchers recommend a clear demarcation between the public relations and human resource function and to build strategic PR departments that embrace internal relationship management.&#x0D; Keywords: Relationship management, employee-organisation relationships, public relations, organisation-public relationships, relationship antecedents

ПОТЕНЦИАЛ КОРПОРАТИВНОГО МУЗЕЯ КАК ОДНОГО ИЗ ИНСТРУМЕНТОВ ВНУТРИКОРПОРАТИВНОГО PR

In the current economic conditions, both the internal and external image of the company plays a significant role in forming a loyal audience and maintaining a high level of sales. External and internal PR are closely interrelated. Therefore, to achieve the success of the organization, it is necessary to pay attention to each direction. Maintaining a comfortable corporate climate is one of the most important tasks of any company's management. And in difficult conditions for the company, the value of the internal PR function increases many times. A review of existing corporate museums on the territory of the Republic of Bashkortostan, by means of monitoring sites of the company engaged in the creation of such museums "turnkey". We discovered that there is a company such as the Russian Museum and exhibition company, registered in Ufa, which accepts Republican orders, as well as orders from neighboring Republics and in General many leading and leading companies in Russia. Existing corporate museums have a fairly narrow target audience. The first example of a corporate Museum is related to the legal sphere, hence the corresponding audience.

Impaired LH surge amplitude in gonadotrope-specific progesterone receptor knockout mice

The progesterone receptor (PR, encoded by Pgr) plays essential roles in reproduction. Female mice lacking the PR are infertile, due to the loss of the protein's functions in the brain, ovary, and uterus. PR is also expressed in pituitary gonadotrope cells, but its specific role therein has not been assessed in vivo. We therefore generated gonadotrope-specific Pgr conditional knockout mice (cKO) using the Cre-LoxP system. Overall, both female and male cKO mice appeared phenotypically normal. cKO females displayed regular estrous cycles (vaginal cytology) and normal fertility (litter size and frequency). Reproductive organ weights were comparable between wild-type and cKO mice of both sexes, as were production and secretion of the gonadotropins, LH and FSH, with one exception. On the afternoon of proestrus, the amplitude of the LH surge was blunted in cKO females relative to controls. Contrary to predictions of earlier models, this did not appear to derive from impaired GnRH self-priming. Collectively, these data indicate that PR function in gonadotropes may be limited to regulation of LH surge amplitude in female mice via a currently unknown mechanism.

Resident Perspectives

Resident Perspectives

Multifactorial Regulation of Myometrial Contractility During Pregnancy and Parturition

The steroid hormones progesterone (P4) and estradiol-17β (E2), produced by the placenta in humans and the ovaries in rodents, serve crucial roles in the maintenance of pregnancy, and the initiation of parturition. Because of their critical importance for species survival, the mechanisms whereby P4 and its nuclear receptor (PR) maintain myometrial quiescence during pregnancy, and for the decline in P4/PR and increase in E2/estrogen receptor (ER) function leading to parturition, are multifaceted, cooperative, and redundant. These actions of P4/PR include: (1) PR interaction with proinflammatory transcription factors, nuclear factor κB (NF-κB), and activating protein 1 (AP-1) bound to promoters of proinflammatory and contractile/contraction-associated protein (CAP) genes and recruitment of corepressors to inhibit NF-κB and AP-1 activation of gene expression; (2) upregulation of inhibitors of proinflammatory transcription factor activation (IκBα, MKP-1); (3) induction of transcriptional repressors of CAP genes (e.g., ZEB1). In rodents and most other mammals, circulating maternal P4 levels remain elevated throughout most of pregnancy and decline precipitously near term. By contrast, in humans, circulating P4 levels and myometrial PR levels remain elevated throughout pregnancy and into labor. However, even in rodents, wherein P4 levels decline near term, P4 levels remain higher than the Kd for PR binding. Thus, parturition is initiated in all species by a series of molecular events that antagonize the P4/PR maintenance of uterine quiescence. These events include: direct interaction of inflammatory transcription factors (e.g., NF-κB, AP-1) with PR; increased expression of P4 metabolizing enzymes; increased expression of truncated/inhibitory PR isoforms; altered expression of PR coactivators and corepressors. This article will review various mechanisms whereby P4 acting through PR isoforms maintains myometrial quiescence during pregnancy as well as those that underlie the decline in PR function leading to labor. The roles of P4- and E2-regulated miRNAs in the regulation and integration of these mechanisms will also be considered.