Coupling of acoustic cavitation with DEM-based particle solvers for modeling de-agglomeration of particle clusters in liquid metals

The aerospace and automotive industries are seeking advanced materials with low weight yet high strength and durability. Aluminum and magnesium-based metal matrix composites with ceramic micro- and nano-reinforcements promise the desirable properties. However, larger surface-area-to-volume ratio in micro- and especially nanoparticles gives rise to van der Waals and adhesion forces that cause the particles to agglomerate in clusters. Such clusters lead to adverse effects on final properties, no longer acting as dislocation anchors but instead becoming defects. Also, agglomeration causes the particle distribution to become uneven, leading to inconsistent properties. To break up clusters, ultrasonic processing may be used via an immersed sonotrode, or alternatively via electromagnetic vibration. This paper combines a fundamental study of acoustic cavitation in liquid aluminum with a study of the interaction forces causing particles to agglomerate, as well as mechanisms of cluster breakup. A non-linear acoustic cavitation model utilizing pressure waves produced by an immersed horn is presented, and then applied to cavitation in liquid aluminum. Physical quantities related to fluid flow and quantities specific to the cavitation solver are passed to a discrete element method particles model. The coupled system is then used for a detailed study of clusters’ breakup by cavitation

Physicians’ assessment of the high blood pressure risk and their attitude towards the prevention of arterial hypertension

Aim. To study the physicians’ knowledge of the high blood pressure (BP) risk and to assess their attitude towards the prevention of arterial hypertension (AH). Material and methods. In total, 118 internal disease specialists from three Russian regions participated in an anonymous questionnaire survey on the knowledge of high BP risk and the attitude towards the prevention of AH and its complications. The mean age of participants (13 men and 105 women) was 46,53±11,64 years. The respondents’ answers were compared to the information in the current clinical AH guidelines. Results. More than one-half of the respondents demonstrated inadequate professional knowledge on prediction and prevention of AH complications. These physicians use the “traditional” disease model and do not consider elevated BP as a risk factor; predict the risk of AH complications using subjective complaints of their patients; do not realise the importance of the target organ damage (TOD) prevention; and limit their preventive strategy only to the prevention of hypertensive crises. Conclusion. The demonstrated attitude towards AH management could be a serious barrier for effective AH prevention. This group of physicians needs extensive education and training, in order to modify their attitude and to increase their commitment to preventive strategies

Lost criteria

Physicians have been found to be inadequately aware of the structure of the causes of headache, vertigo, and their clinical importance in patients with essential hypertension. Incorrect ideas lead to the unfounded application of diagnostic techniques for imaging the great arteries of the head and to extremely simplified approaches to treating cerebrovascular diseases as short-term courses of therapy with vasoactive and metabolic agents

Physicians’ assessment of the high blood pressure risk and their attitude towards the prevention of arterial hypertension

Aim. To study the physicians’ knowledge of the high blood pressure (BP) risk and to assess their attitude towards the prevention of arterial hypertension (AH). Material and methods. In total, 118 internal disease specialists from three Russian regions participated in an anonymous questionnaire survey on the knowledge of high BP risk and the attitude towards the prevention of AH and its complications. The mean age of participants (13 men and 105 women) was 46,53±11,64 years. The respondents’ answers were compared to the information in the current clinical AH guidelines. Results. More than one-half of the respondents demonstrated inadequate professional knowledge on prediction and prevention of AH complications. These physicians use the “traditional” disease model and do not consider elevated BP as a risk factor; predict the risk of AH complications using subjective complaints of their patients; do not realise the importance of the target organ damage (TOD) prevention; and limit their preventive strategy only to the prevention of hypertensive crises. Conclusion. The demonstrated attitude towards AH management could be a serious barrier for effective AH prevention. This group of physicians needs extensive education and training, in order to modify their attitude and to increase their commitment to preventive strategies.</jats:p

AN ASSESSMENT OF ALGAL COMMUNITES IN WETLANDS LOCATED ABOVE AND BELOW THE GEORGIA FALL LINE

Wetlands are important aquatic habitats that provide a variety of ecosystem services beneficial to all organisms. These services include improving water quality, storing excess water during floods, and maintaining global climate conditions through several nutrient cycles. Algae are an integral part of aquatic habitats as essential primary producers and important bioindicators of water quality alterations. This study was conducted as an assessment of water quality based on algal biomass in wetlands north (the Piedmont Plateau) and south (Coastal Plain) of the Fall Line. One wetland from each region was selected and compared based on mineral contents, nutrient availability, organic material, primary production, and hydrologic properties based on its soils physical and chemical makeup. YSI and BenthoTorch measurements were taken in the field, and algal samples were collected and analyzed in the lab for Chlorophyll α concentrations using bbe AlgaeGuard. Comparisons between wetlands and between measurements of primary production in the field and in the lab were evaluated with two-sample Hotelling’s T-square tests. Based on the physical parameters tested, the wetlands were significantly different only in dissolved oxygen (p\u3c0.001, but were not different in pH (p=0.297), conductivity (p=0.097) and temperature (p=0.882). Total chlorophyll a measured in the lab was not significantly different (p=0.171), but due to significant difference in Si (p=0.027), K (p=0.004) and hardness (p=0.008) there were different algal compositions in each wetland. Green algae dominated algal community in the Babe and Sage farm wetland (south of the Fall line), due to higher nutrient content exposure. The Bartram forest wetland, north of the Fall line had lower sunlight exposure, was further from human activities, and primary production was dominated by diatoms

Calothrix-An evaluation of fresh water species in United States rivers and streams, their distribution and preliminary ecological findings

This study examines the distribution and ecology of the morphologically complex genus Calothrix, which contains species particularly hard to identify due to morphological variability with changing water conditions. Up to a dozen species have been reported previously in US freshwater environments. Using literature review to establish previously reported occurrences and the extensive dataset from the Environmental Protection Agency National River and Streams Assessment, this study mapped the current confirmed distribution of 7 species in United States rivers and streams. Results from data analysis showed Calothrix spp. occurring in 42 States and establish its occurrence in both flowing and standing, typically alkaline or neutral waters. Ecological traits exhibited by individual species included C. fusca (Kützing) Bornet & Flahault indicating pH may be a limiting factor, with this species preferring more alkaline waters. In addition, conductivity levels influenced filament structure. Data indicates that Calothrix epiphytica West & G.S. West responds to higher light availability and is also influences by turbidity levels. This study expands our ecological knowledge of species belonging to the genus Calothrix, begins to document the current distribution of these species and the morphological data presented represent the first metapopulation data summary for US Calothrix distribution. The study also confirms the need for a polyphasic approach when studying this group and suggests that molecular data be incorporated into continent-wide studies in the future

Algal Extremophile Community Persistence from Hot Springs National Park (Arkansas, U.S.A.)

Algae have been observed in many different extreme environments especially in thermal springs. On June 16th, 2006, we conducted an algal taxonomic survey from Hot Springs National Park, Hot Springs, Arkansas. We sampled algal mats and plankton at 2 different springs and 3 fountains near the Visitor Center along Bathhouse row. The spring\u27s temperatures ranged from 38 to 57 oC and higher temperatures were correlated (p \u3c 0.05) to lower species numbers observed at the sampling sites. We identified 45 algal species with Cyanoprokaryotes (cyanobacteria) having 29 species (64.4% of the total) and diatoms had 16 species (45.6% of the total). The algal mat biomass was dominated by Anabeana variablilis (80%) and Hapalosiphon major (10%). Diatoms were only observed in two springs at lower temperature sites (\u3c 40 oC) and epiphytically on mosses

Comparative evaluation of patients and symptoms of hypertension in the provision of primary health care

Тюков Ю.А., доктор медицинских наук, профессор, заведующий кафедрой общественного здоровья и здравоохранения, Челябинская государственная медицинская академия (г. Челябинск). Манойлов А.Е., кандидат медицинских наук, доцент кафедры безопасности жизнедеятельности, медицины катастроф скорой и неотложной медицинской помощи, Челябинская государственная медицинская академия (Челябинск). Теринова В.В., соискатель кафедры общественного здоровья и здравоохранения, Челябинская государственная медицинская академия (Челябинск). Воронцов Т.Н., ассистент кафедры общественного здоровья и здравоохранения, Челябинская государственная медицинская академия (Челябинск). Кузнецова Л.М., ассистент кафедры общественного здоровья и здравоохранения, Челябинская государственная медицинская академия (Челябинск). Котов А.А., кандидат медицинских наук, доцент кафедры общественного здоровья и здравоохранения, Челябинская государственная медицинская академия (Челябинск). Tukov Yu.A., Doctor of Medical Sciences (Grand MD), Professor, Head of the Department of Public Health and Health Care, Chelyabinsk State Medical Academy. Manoylov A.E., Candidate of Medical Sciences (PhD), Associate Professor of the Department of Life Safety, Disaster Medicine of Emergency Care, Chelyabinsk State Medical Academy. Terinova V.V., Applicant for scientific degree at the Department of Public Health and Health Care, Chelyabinsk State Medical Academy. Vorontsov T.N., Assistant, post-graduate of the Department of Public Health and Health Care, Chelyabinsk State Medical Academy. Kuznetsova L.M., Assistant, post-graduate of the Department of Life Safety, Disaster Medicine of Emergency Care, Chelyabinsk State Medical Academy. Kotov A.A., Candidate of Medical Sciences (PhD), Associate Professor of the Department of Public Health and Health Care, Chelyabinsk State Medical Academy.Исследование проведено с целью сопоставления оценки симптомов пациентами и диагностики причин повышения артериального давления у лиц вызывающих скорую помощь на дом, и осведомленность медицинских специалистов о клинических проявлениях гипертонии. В качестве материала исследования взята ретроспективная информация оперативного отдела автоматизированной системы управления станции скорой помощи города Челябинска за 2002–2011 гг. – 4000 карт вызовов, результаты анонимного анкетирования 276 участковых терапевтов и 138 медицинских работников скорой медицинской помощи. В результате проведенного исследования установлено несоответствие числа поводов вызова скорой помощи фактической клинике течения заболевания. Research was conducted to compare arterial hypertension symptoms assessments by patients and diagnostics of arterial pressure increase reasons at persons causing ambulance at home, also medical-experts knowledge of hypertension clinical manifestations were estimated. Retrospective information from an automated control system of the Chelyabinsk ambulance station for 2002–2011 was used: 4000 cards of phone-calls; anonymous questioning results of 276 local therapists and 138 medical workers of an emergency medical service. As a result discrepancy of number of ambulance calls occasions to the actual disease cases was established