Liquid and liquid-gas flows at all speeds : Reference solutions and numerical schemes

This paper present some reference solutions to be used in order to validate and improve numerical schemes for multiphase flows. We address here exact one-dimensional liquid and liquid-gas compressible flows solutions in nozzles. The exact solution is first derived for the compressible single liquid phase Euler equations and extends the well known ideal gas dynamic nozzle flow solutions.The all Mach number scheme is then derived. A preconditioned Riemann solver is built and embedded into the Godunov explicit scheme. It is shown that this method converges to exact solutions but needs too small time steps to be efficient. An implicit version is then derived, in one dimension first and second in the frame of 3D unstructured meshes

Propositions de méthodes et modèles eulériens pour les problèmes à interfaces entre fluides compressibles en présence de transfert de chaleur

On évalue différentes formulations euleriennes aptes au traitement de problèmes à interfaces entre fluides compressibles. La difficulté dans ce type de problème réside dans le calcul des variables thermodynamiques dans les zones de diffusion numériques produites aux interfaces. En effet, tout schéma eulérien diffuse artificiellement les discontinuités de contact (ou interfaces) et produit donc un mélange artificiel pour lequel la détermina- tion de l'état thermodynamique est difficile. De plus, lorsque l'état thermodynamique est mal déterminé, les méthodes échouent très rapidement en raison de pressions négatives ou d'arguments négatifs dans le calcul de la vitesse du son. Les modèles et les méthodes de résolution qui sont évaluées n'ont jamais été examinées pour le calcul de la température aux interfaces. L'examen des défauts et avantages de ces formulations nous conduit à en rejeter certaines et à en proposer une nouvelle, très efficace. Ce nouveau modèle est accompagné de son schéma numérique. On présente ensuite le traitement des transferts diffusifs aux interfaces, puis un exemple de résolution en deux dimensions d'espace. L'évaluation est effectuée sur une série de problèmes possédant des solutions exactes

Extrinsic Factors Influencing the Person’s Motivation for Engagement and Retention in the Addiction Recovery Process. A Systematic Literature Review

Background Globally, up to 80% of patients enrolled for addiction care are lost to follow-up within the first three months of treatment. This review synthesizes evidence on extrinsic factors that influence motivation for engaging in addiction recovery and corresponding empirical definitions. Methods A systematic search for peer-reviewed articles was conducted through electronic databases, including Ovid MEDLINE, PsychINFO, CINHAL, and scanning references. The included articles were published in English or French between 1946 and 2018. Results The identified sixteen articles indicated that extrinsic factors for the person’s engagement and retention in the addiction recovery process included: motivation-enhancing healthcare structures, therapeutic relationships, and supportive social networks. Results also indicated that empirical definitions of motivation for engagement and retention in the addiction recovery process varied across studies. Conclusion Extrinsic factors can influence the person’s motivation for engagement and retention in the addiction recovery. Research with full operational definitions of motivation for engagement and retention in the addiction recovery is needed. Keywords: Addiction recovery; engagement; extrinsic factors; motivation; retentio

Расчет магнитного поля, созданного проводником с током в прямоугольном пазу

На основе прямого вариационного метода Канторовича получена приближенная аналитическая формула для векторного магнитного потенциала в области сечения прямоугольного паза с ферромагнитными стенками. Поле создается прямолинейным проводником с током при обычных допущениях: бесконечно большая магнитная проницаемость ферромагнитной среды и отсутствие выпучивания потока у открытой стороны паза

Маркетинговая стратегия компании British Petroleum в меняющейся бизнес-среде

Changing environmental factors create new conditions for their operating, which often require considerable and serious changes in strategic decision-making and positioning of companies. Inflexible and rigid firms will cease to be competitive in the market every time changes occur. The aim of the present report is to identify the past and present changes in marketing strategy of British Petroleum, which have occurred under the pressure of environmental factors

Using information communication technologies to increase the institutional capacity of local health organisations in Africa: a case study of the Kenya Civil Society Portal for Health

Introduction: achieving the healthcare components of the United Nations' Millennium Development Goals is significantly premised on effective service delivery by civil society organisations (CSOs).However, many CSOs across Africalack the necessary capacity to perform this role robustly. This paper reports on an evaluation of the use, and perceived impact, of aknowledge management tool upon institutional strengthening among CSOs working in Kenya's health sector. Methods: three methods were used: analytics data; user satisfaction surveys; and a furtherkey informant survey. Results: satisfaction with the portal was consistently high, with 99% finding the quality and relevance of the content very good or good for institutional strengthening standards, governance, and planning and resource mobilisation. Critical facilitators to the success of knowledge management for CSO institutional strengthening were identified as people/culture (developed resources and organisational narratives) and technology (easily accessible, enabling information exchange, tools/resources available, access to consultants/partners).Critical barriers were identified as people/culture (database limitations, materials limitations, and lack of active users), and process (limited access, limited interactions, and limited approval process). Conclusion: this pilot study demonstrated the perceived utility of a web-based knowledge management portal among developing nations' CSOs, with widespread satisfaction across multiple domains, which increased over time. Providing increased opportunities for collective mutual learning, promoting a culture of data use for decision making, and encouraging all health organisations to be learning institutions should be a priority for those interested in promoting sustainable long-term solutions for Africa.Keywords: Africa, capacity building, data for decision making, ICT for development, developing countries, Kenya, knowledge managemen

Electronic structure, chemical bonding, and magnetic properties in the intermetallic series Sc2Fe(Ru1−xRhx)5B2 from first principles

First-principles, density-functional studies of the electronic structure, chemical bonding, ground-state magnetic ordering, and exchange-interaction parameters have been performed for the entire Sc2Fe(Ru1−xRhx)5B2 series of magnetic compounds. The results indicate that their magnetic properties depend in an extremely sensitive way on the degree of band filling and bandwidth. Continuous substitution of Ru by Rh changes the ground state from an antiferromagnet to a ferromagnet, as well as increases the effective spin moment caused by filling the bands with five additional electrons per formula unit together with a narrowing of the 4d band. The correlations between the character of the chemical bonding and the resulting exchange couplings are discussed. The enhancement of Fe-Fe exchange coupling caused by Rh∕Ru atoms is estimated. Trends for the macroscopic ordering temperatures are correctly reproduced