Mould filling simulation in high pressure die casting by meshless method

Simulation of mould filling in high pressure die casting has been an attractive area of research for many years. Several numerical methodologies have been adopted in the past to study the flow behaviour of the molten metal inside the die cavities. However, many of these methods require stationary mesh or grid which limits their ability in simulating highly dynamic and transient flows encountered in high pressure die casting processes. In recent years, the advent of meshfree methods have led to the opening of new avenues in numerical computational field. Consequently, particle based methods have emerged as an attractive alternative for modeling mould filling simulation in pressure die casting processes. In this paper the Corrected Smooth Particle Hydrodynamics (CSPH) method is used to simulate fluid flow in the high pressure die casting cavity. CSPH is a Lagrangian method based on Smooth Particle Hydrodynamics (SPH) techniques. In CSPH method, the quantities determining the flow are localised on set of particles, which move with the flow. This enables the method to easily follow complex free surfaces, including fragmentation. This paper mainly deals with the formulation of governing equation required CSPH simulation of high pressure die casting process and presents a number of numerical results to demonstrate the capabilities of the numerical model

Prescribing and using self-injectable antiretrovirals: How concordant are physician and patient perspectives?

The selection of agents for any treatment regimen is in part influenced by physician and patient attitudes. This study investigated attitudinal motivators and barriers to the use of self-injectable antiretroviral agents among physicians and patients and measured the degree of concordance between physician and patient perspectives

Severe ocular Mpox in person living with advanced HIV treated with extended course of tecovirimat.

BACKGROUND: People living with HIV are disproportionately represented among people with severe mpox. Mild and self-limiting conjunctival involvement has been well-documented, and severe ocular complications, including keratitis, corneal scarring, and the associated loss of vision, are increasingly recognized. Tecovirimat is the first-line antiviral therapy for severe mpox, but data around the efficacy of systemic antiviral agents for mpox are limited, particularly in cases of ocular mpox. CASE REPORT: Here, we describe a case of sight-threatening necrotic blepharokeratoconjunctivitis in a person with advanced HIV, requiring an extended course of tecovirimat due to persistent mpox viral shedding for nearly 5 months

3D modelling of the flow of self-compacting concrete with or without steel fibres. Part I: slump flow test

In part I of this two-part paper, a three-dimensional Lagrangian smooth particle hydrodynamics method has been used to model the flow of self-compacting concrete (SCC) with or without short steel fibres in the slump cone test. The constitutive behaviour of this non-Newtonian viscous fluid is described by a Bingham-type model. The 3D simulation of SCC without fibres is focused on the distribution of large aggregates (larger than or equal to 8 mm) during the flow. The simulation of self-compacting high- and ultra-high- performance concrete containing short steel fibres is focused on the distribution of fibres and their orientation during the flow. The simulation results show that the fibres and/or heavier aggregates do not precipitate but remain homogeneously distributed in the mix throughout the flow

Smoking and drinking in relation to oral potentially malignant disorders in Puerto Rico: a case-control study

<p>Abstract</p> <p>Background</p> <p>Oral cancer incidence is high on the Island of Puerto Rico (PR), particularly among males. As part of a larger study conducted in PR, we evaluated smoking and drinking as risk factors for oral potentially malignant disorders (OPMDs).</p> <p>Methods</p> <p>Persons diagnosed with either an OPMD (n = 86) [oral epithelial dysplasia (OED), oral hyperkeratosis/epithelial hyperplasia without OED] or a benign oral tissue condition (n = 155) were identified through PR pathology laboratories. Subjects were interviewed using a standardized, structured questionnaire that obtained information, including detailed histories of smoking and drinking. Odds ratios (ORs) for smoking and drinking in relation to having an OPMD, relative to persons with a benign oral tissue condition, were obtained using logistic regression and adjusted for age, gender, education, fruit/vegetable intake and smoking or drinking.</p> <p>Results</p> <p>For persons with an OPMD and relative to individuals with a benign oral tissue condition, the adjusted OR for current smoking was 4.32 (95% CI: 1.99-9.38), while for former smokers, the OR_adjwas 1.47 (95% CI: 0.67-3.21), each OR_adjrelative to never smokers. With regard to drinking, no adjusted ORs approached statistical significance, and few point estimates exceeded 1.0, whether consumption was defined in terms of ever, current, level (drinks/week), or beverage type.</p> <p>Conclusions</p> <p>In this study, conducted in Puerto Rico, current smoking was a substantial risk factor for OPMDs while former smokers had a considerably reduced risk compared to current smokers. There was little evidence suggesting that alcohol consumption was positively associated with OPMD risk.</p

Development of Scientific Competences in Chemistry Courses

Enseñar química en los primeros años de educación universitaria es clave en la formación de futuros profesionales, puesto que, además de proveer los conocimientos que aportan las ciencias básicas, contribuye al desarrollo de competencias científicas para que el estudiante resuelva problemas reales, a partir de la búsqueda adecuada de información en fuentes confiables y su lectura, con el propósito de desarrollar habilidades analíticas, críticas y creativas. Es por esto que, como estrategia de innovación pedagógica, el Departamento de Ciencias Básicas de la Universidad de La Salle ha venido implementando desde el año 2016 la formulación de un proyecto de investigación en los cursos de química. En el marco de esta estrategia, desde el II-2018 las autoras se abocaron a la reflexión e implementación de la estrategia didáctica que propende por el desarrollo de competencias científicas en los cursos de Química General, Química Orgánica y Bioquímica desde tareas, investigación y aprendizaje de problemáticas vigentes en Colombia y en el mundo.Abstract: Teaching chemistry in the first years of university education is key in the training of future professionals since, in addition to providing the knowledge of the basic sciences, it contributes to the development of scientific skills that lead to the student to solve real problems, starting from the appropriate search of information in reliable sources and its reading with the purpose of developing analytical, critical and creative skills. Therefore, as a pedagogical innovation strategy, the formulation of a research project in chemistry courses has been implemented since 2016 by the Department of Basic Sciences of the Universidad de La Salle. Within the framework of this strategy, from II-2018 the authors focused on the reflection and implementation of the didactic strategy that depends on the development of scientific competences in the courses of General Chemistry, Organic Chemistry and Biochemistry from tasks, research and learning of current problems in Colombia or in the world