Petroleum-wax separation

A process for dewaxing is described. It includes the steps of mixing a waxy feedstock near its pour point with an ambient or below ambient temperature solvent essentially free of a selected cosolvent, to form a solvent/feedstock mixture, and subsequently adding the cosolvent to the solvent/feedstock mixture to cause instantaneous precipitation of wax on addition of cosolvent. The amount of wax precipitation is controlled by the quantity and temperature of the cosolvent added. The cosolvent is essentially completely miscible with the solvent, but immiscible with the oil and wax. For example, alcohols (methanol, ethanol, propanol), ketones (ketene, acetone), amines, etc. The process of the present invention provides the advantages of lower solvent ratios (higher solvent recovery), higher filtration temperatures, “environmentally compatible” solvents, rapid filtration rates, and debottlenecking of existing dewaxing plants

Petroleum-wax separation

A process for dewaxing is described. It includes the steps of mixing a waxy feedstock near its pour point with an ambient or below ambient temperature solvent essentially free of a selected cosolvent, to form a solvent/feedstock mixture, and subsequently adding the cosolvent to the solvent/feedstock mixture to cause instantaneous precipitation of wax on addition of cosolvent. The amount of wax precipitation is controlled by the quantity and temperature of the cosolvent added. The cosolvent is essentially completely miscible with the solvent, but immiscible with the oil and wax. For example, alcohols (methanol, ethanol, propanol), ketones (ketene, acetone), amines, etc. The process of the present invention provides the advantages of lower solvent ratios (higher solvent recovery), higher filtration temperatures, “environmentally compatible” solvents, rapid filtration rates, and debottlenecking of existing dewaxing plants

Process for petroleum-wax separation at or above room temperature

Processes for separating waxes of different melting points from a room temperature amorphous or liquid hydrocarbon mixture in an energy conservative manner by selectively causing precipitation of crystallized waxes are disclosed. The processes involve the use of a selected co-solvent totally miscible with light and intermediate hydrocarbons from a group consisting of acetone, ketene, propanone, 2-propanone, methanol, ethanol, isopropanol, N-propanol, acetic acid, formic acid, and propionic acid or combinations thereof as a precipitating agent. Hydrocarbon mixtures, especially those with elevated pour points are first diluted by solvents such as toluene and/or methyl ethyl ketone which must be free of any significant quantity of the aforesaid co-solvents. The diluted hydrocarbon mixture at above 50° F is mixed with one or more of such selected co-solvents in a ratio preferably between 1:1 and 10:1 by weight to the heavy hydrocarbon content of the mixture; five minutes or more without artificial cooling is allowed to permit crystallization of waxes which are removed in solid form by a physical process such as filtering, settling, or the like. By controlling the amount and nature of the selected co-solvent and by including or excluding water or brine with the co-solvent, valuable waxes of high melting point may be selectively separated, or all waxes may be removed indiscriminately. Performing the separation process in several stages of adding co-solvent and/or water permits selecting out more valuable high melting point waxes first before succeeding stages reduce the wax content of the remaining liquid hydrocarbon to minimal values to enhance its value

The Experiences of Healthcare Professional Students about the Educational Impacts of Mobile Learning

The role of mobile devices in learning processes is growing rapidly and it is imperative to assess the effect of this technology. This paper explores the experience of healthcare professional students with regard to the educational impacts of mobile learning. We conducted a qualitative study using a conventional qualitative content analysis based on Graneheim and Lundman (2004) method to collect and analyze the experiences of 23 healthcare professional students. Two themes, each with subthemes, emerged from the findings: (1) perceived benefit in learning process, and (2) reflective self-assessment. The results revealed that mobile learning has a positive impact on both the process and the outcome of learning in healthcare professional students. Therefore, creating a supportive condition to promote mobile learning is recommended

Petroleum-wax separation

A process for dewaxing is described. It includes the steps of mixing a waxy feedstock near its pour point with an ambient or below ambient temperature solvent essentially free of a selected cosolvent, to form a solvent/feedstock mixture, and subsequently adding the cosolvent to the solvent/feedstock mixture to cause instantaneous precipitation of wax on addition of cosolvent. The amount of wax precipitation is controlled by the quantity and temperature of the cosolvent added. The cosolvent is essentially completely miscible with the solvent, but immiscible with the oil and wax. For example, alcohols (methanol, ethanol, propanol), ketones (ketene, acetone), amines, etc. The process of the present invention provides the advantages of lower solvent ratios (higher solvent recovery), higher filtration temperatures, “environmentally compatible” solvents, rapid filtration rates, and debottlenecking of existing dewaxing plants

La Paradoja de la Aceptación y el Rechazo: La Percepción de los Estudiantes Profesionales de la Salud sobre la Aceptación del Aprendizaje Móvil en la Universidad de Ciencias Médicas de Irán

Objective: A qualitative study was conducted to explore the perception of healthcare professional students about mobile learning acceptance. Method: The study was performed using a conventional content analysis method. The subjects were the students of medical sciences in Iran University of Medical Science. Sampling was based on a purposeful sampling method. Twenty-three students took part in semi-structured interviews until data saturation was reached. Results: The main theme was “the paradox of acceptance and rejection” with three categories; (1) perceived attraction (sub-categories: learning with the excitement of entertainment, the attraction of multimedia learning environment and enthusiasm for electronic learning); (2) perceived ease (sub-categories: easy access to information anytime and anywhere and easy and effortless use); and (3) perceived conflict (sub-categories: teachers’ contradictory behavioral patterns, contradiction about value of online information, friends’ contradictory behavioral patterns, and digital gap between generations in family). Conclusion: The three categories found in the study placed the students in a dilemma of using or not using mobile learning. They had doubts about accepting mobile technology as a legitimate educational tool. Taking these factors into account and managing them can pave the way for mobile learning in the students.Se realizó un estudio cualitativo para explorar la percepción de los estudiantes profesionales de la salud sobre la aceptación del aprendizaje móvil. El estudio se realizó utilizando un método de análisis de contenido convencional. Los sujetos fueron estudiantes de medicina en la Universidad de Ciencias Médicas de Irán. El muestreo se basó en un método de muestreo útil. Veintitrés estudiantes participaron en entrevistas semiestructuradas hasta que se alcanzó la saturación de datos. El tema principal fue "la paradoja de la aceptación y el rechazo" con tres categorías: (1) atracción percibida (subcategorías: aprendizaje con la emoción del entretenimiento, la atracción del entorno de aprendizaje multimedia y el entusiasmo por el aprendizaje electrónico); (2) facilidad percibida (subcategorías: acceso fácil a la información en cualquier momento y en cualquier lugar y uso fácil y sin esfuerzo); y (3) conflicto percibido (subcategorías: patrones de comportamiento contradictorios de los docentes, contradicción sobre el valor de la información en línea, patrones de comportamiento contradictorios de los amigos y brecha digital entre generaciones en la familia). Las tres categorías encontradas en el estudio colocaron a los estudiantes en un dilema de usar o no el aprendizaje móvil. Tenían dudas sobre la aceptación de la tecnología móvil como una herramienta educativa legítima. Tener en cuenta estos factores y gestionarlos puede allanar el camino para el aprendizaje móvil en los estudiantes

Evaluating the relationship between serum immunoglobulin G (IgG) and A (IgA) anti-cagA antibody and the cagA gene in patients with dyspepsia

Peer reviewedPublisher PD

How to develop clinical reasoning in medical students and interns based on illness script theory : An experimental study

Acknowledgments Authors would like to acknowledge Iran University of Medical Sciences for providing financial support. Extend thanks to medical students and interns for their participation in the study. Funding The present study was financially supported by Iran University of Medical Sciences, for partial fulfillment of Ph.D. dissertation, (Grant No: 6784). The funding organization did not play any roles in the study design, collection, analysis, and interpretation of data, or in writing the manuscript.Peer reviewedPublisher PD

The educational effects of mobile learning on students of medical sciences: A systematic review in experimental studies

Introduction: The demand for mobile learning in the medical sciences educational program is increasing. The present review study gathers evidence highlighted by the experimental studies on the educational effects of mobile learning for medical sciences students. Methods: The study was carried out as a systematic literature search published from 2007 to July 2017 in the databases PubMed/ Medline, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Web of Knowledge (Thomson Reuters), Educational Resources and Information Center (ERIC), EMBASE (Elsevier), Cochrane library, PsycINFO and Google Scholar. To examine quality of the articles, a tool validated by the BEME Review was employed. Results: Totally, 21 papers entered the study. Three main themes emerged from the content of papers: (1) improvement in student clinical competency and confidence, (2) acquisition and enhancing of students’ theoretical knowledge, and (3) students’ positive attitudes to and perception of mobile learning. Level 2B of Kirkpatrick hierarchy had been examined by all the papers and seven of them had reported two or more outcome levels, but level 4 was not reported in the papers. Conclusion: Our review showed that the students of medical sciences had positive response and attitudes to mobile learning. Moreover, implementation of mobile learning in medical sciences program might lead to valuable educational benefits and improve clinical competence and confidence along with theoretical knowledge, attitudes, and perception of mobile learning. The results indicated that mobile learning strategy in medical education can positively affect learning in all three domains of Bloom’s Taxonomy

Challenging script concordance test reference standard by evidence : Do judgments by emergency medicine consultants agree with likelihood ratios?

Acknowledgements We would like to acknowledge Dr. Amir Nejati for his contributions in collecting data for this study. Sources of funding This study was the M.D. thesis of SK and was funded by Iran University of Medical Sciences. The authors have not received fund from any other source.Peer reviewedPublisher PD