Prediction of tip vortex cavitation inception on marine propellers at an early design stage

The inception of vortex cavitation at an early design stage is still difficult to forecast. The most reliable prediction of the full scale performance is achieved by means of model tests, which are possible for few designs only. A simplified model to calculate the inception of tip vortex cavitation is developed and tested. The model is based on results obtained from potential flow theory, using a boundary element method. The developed tip vortex cavitation inception model and also the panel method are described, after a short introduction to vortex cavitation. The numerical behaviour of the model is investigated for an elliptic wing at different angles of attack and two marine propellers in homogenous and not axially symmetric inflow. The cavitation model s properties concerning different Reynolds numbers are studied and the scale effects on calculated model- and full-scale tip vortices are discussed.http://deepblue.lib.umich.edu/bitstream/2027.42/84317/1/CAV2009-final143.pd

Vorticity Confinement methods for cavitating flows

Present work deals with investigations of numerical aspects of cavitating vortex dominated flows. Computations of the viscous flow on realistic, technical configurations require efficient methods and high grid resolution, which is not sufficient in most cases to capture important details of the flow. Insufficient resolution increases the numerical dissipation of vortices generated at the tip region of lifting surfaces. One possible solution to reduce the unphysical decay of the strength of the vortices (despite of moderate resolution) is the application of vorticity confinement methods. Aim of the paper is the development and the comparison of Vorticity Confinement (VC) methods for cavitating flows on unstructured grids. Applications are proposed to control devices and marine propulsion systems. The numerical dissipation of vortices is compared for different VC formulations. Especially the influence of the source terms on cavitating flows is investigated. The numerical computations are carried out by the finite volume solution method FreSCo on arbitrary grids. In the study vorticity confinement techniques are combined with different cavitation models available in the applied numerical method to investigate tip vortex flow. The cavitation models are based on Volume-of-Fluid (VoF). A NACA16020 elliptical wing is selected as a validation case. The combination of vorticity confinement formulations and cavitation models enables a better and a more detailed study of cavitation effects.http://deepblue.lib.umich.edu/bitstream/2027.42/84314/1/CAV2009-final139.pd

Dietary Behavior Related to Cancer Prevention in a Low Income Community

Background: The incidence of cancer is increasing in developing countries. Diet and cancer have a close relationship. Objectives: The objectives of this study were to measure the cancer prevention-related nutrition knowledge, attitudes, and practice and barriers related to healthy food in a low income community, and to assess their cancer worries. Subjects and Methods: This cross-section descriptive study was carried out in a slum area in Cairo on a convenience sample of 414 adults permanently residing in the area. A structured interview questionnaire was used for collecting participants' socio-demographic data, knowledge about cancer, attitude and practice towards cancer dietary prevention, cancer worry scale, and the barriers preventing eating healthy food. Results: The study revealed a wide range of participants' knowledge scores. Participants' attitude towards a healthy diet was also low. The most deficient practices were related to the intake of balanced diet and vitamins, practice of exercise, and cancer screening.  The most frequent barrier to a healthy diet was taste (42%), while the lack of information was the least (3.1%). Multivariate analysis showed that the knowledge score was positively predicted by cancer worry score. The attitude score was positively predicted by age and knowledge score, and the practice score by married status, crowding index, and attitude score. Conclusion: there is a poor level of knowledge and inadequate practices regarding cancer dietary prevention despite good attitudes, in addition to high worries about cancer. Implications for Practice: There is urgent need for awareness raising intervention programs for dietary prevention of cancer. Keywords: Cancer, Diet, Knowledge, Attitude, Practice, Barrie

Improve Knowledge, Beliefs and Behavior of Undergraduate Female Nursing Students in Al-Alzhar University toward Breast Self-Examination Practice

Breast cancer is a public health problem that is most common form of cancer among females in both developed and developing world, The Health Belief Model (HBM) has been used as a theoretical framework to study Breast Self-Examination and other breast cancer detection behaviors. The aim of this study: Was to improve knowledge, beliefs and behavior of undergraduate female nursing students in Al-Alzhar University toward breast self examination practice. Design: A quasi-experimental design was used in this study. Setting: The study was conducted in Health Technical Institute for female students at Al-Alzhar University for 113female student nurse. Tools: data was collected using self administered questionnaires prepared by researchers and Health Belief Model Scale Data. Results: The participants in the study showed more deficiency on screening knowledge, and poor practice of BSE at pre education. Also, the results of this study highlight the positive impact of the educational training on nursing students’ breast cancer and breast self exam  knowledge, practice and health beliefs which there was statistically significant differences were found between students' pretest and posttest BSE Knowledge, practice and  beliefs. Conclusion and recommendation: the results of this study concluded that this program could be instrumental in increasing nursing students’ perception of susceptibility may serve to improve not only their own health status but may empower them to teach women about the importance of early diagnosis and to seek early medical advice. This study emphasizes that the need to teach nursing students breast cancer awareness and early detection of breast cancer in their undergraduate courses. In addition, the provision of regular interventions is necessary to increase and build up the confidence and skills of nursing students in teaching preventive health behaviors including BSE to society and other students as colleagues. Keywords: Breast Self Exam (BSE), Breast Cancer, Nursing Students, Health Beliefs Mode

Workplace Psychosocial Factors and Mental Health among a Sample of Expatriates and the Country’s Nationals Who Working at King Khalid University, Saudi Arabia

Worplace stress is the harmful physical and emotional response that occurs when there is a poor match between job demands and the capabilities, resources, or needs of the worker. Mental health is an important issue in the workplace, particularly in developing countries. This study was aimed to explore the workplace psychosocial factors and mental health among expatriates and the country’s nationals; examine the relationship between workplace psychosocial factors and mental health. . The sample was composed of 518 country's nationals and 554 expatriates teaching staff on job at King Khalid University. Two tools were used for data collection: Socio-demographic data sheet, and Copenhagen Psychosocial Questionnaire (COPSOQ). The study results indicated that Poor mental health had a strongly statistically significant positive correlation with “quantitative  demands”,” Work-family conflict”, and “Emotional demands “ in total country’s nationals and expatriates   (p<0.01). While it was a strongly statistically significant negative  correlation with “Work pace”, “Influence at work”, “Social support from colleague”, “Social support from supervisors”, “Meaning of work”, “Commitment to the workplace” “Predictability”, and  “Recognition” (p<0.01). It was concluded that country's nationals experience worse mental health than expatriates and  this  to some extent caused by exposure to psychosocial factors at work. It has indicated the importance of taking action to reduce psychosocial factors, as this would benefit both country’s nationals and expatriate workers. Key words: Expatriates , country's nationals , workplace psychosocial factors, mental health

Coffee grounds as a soil conditioner: Effects on physical and mechanical properties – II. Effects on mechanical properties

Applying coffee grounds (CG) to sandy, calcareous, and clayey soils resulted in notable effects on soil expansion, cracking, cohesion, internal friction, initial stress and resistance to penetration. In sand, expansion upon saturation was greater after wetting-and-drying cycles. Highest increases were 15.71%, 16.14% and 31.86% for sandy, calcareous and clayey soils, respectively. Effect of CG on cracking was negligible in sand and very slight (<1.0%) in the calcareous soil but marked in clay (14.18% at 10% CG). In sand, cohesion (c) increased significantly with CG up to the 10% content. Cohesion increased by 2.5-folds and 4.5-folds at 5% and 10% CG, respectively. The presence of fine CG grains among larger sand particles, boosted microbial activities, and the resulting cementing and binding effects resulted in increased cohesion. For calcareous soil, cohesion rose from 0.04 kg∙cm-2 to 0.13 kg∙cm-2 as CG increased from 0% to 15%. In clay, maximum cohesion (0.20 kg∙cm-2) was associated with the 10% CG and was highest of all soils. In sand, the angle of internal friction (φ) decreased notably as CG increased from 5% to 10% but there was no consistent pattern in any of the soils. An increase in initial stress (pi) was observed between 0% and 10% CG in sand and between 0% and 15% in calcareous soil while clay showed no particular trend. Patterns of pi were, thus, consistent with those of cohesion for all soils. Resistance to penetration increased substantially with CG in sand. The effect in calcareous and clayey soils took an opposite trend to that of sand and resistance was generally higher in calcareous soil. Overall effects of CG on resistance were desirable in all soils as far as agriculture (seedling emergence, crop growth, irrigation, etc.) is concerned

Coffee Grounds as a Soil Conditioner: Effects on Physical and Mechanical Properties - I. Effects on Physical Properties

Coffee grounds (CG) improved some soil physical properties (dry density, gd; porosity, n; aggregation; hydraulic conductivity, Ks; and infiltration rate, IR). Effects on other properties were inconsistent (e.g., sorptivity, S), or unfavorable (e.g., available water, AW). gd decreased and n increased with CG. CG decreased Ks in sand. In calcareous soil, maximum increase was associated with 10% and 15% CG before and after wetting-and-drying cycles (WDC), respectively. Ks increased with CG in clay, with greatest increase attained at 10% CG. IR decreased with CG in sand. In calcareous and clayey soils, IR decreased with CG before WDC but increased after WDC where maximum increase in clay was linked to 10% CG. No solid trends of soil sorptivity, S, were identified. Before WDC, S had the order: sand > calcareous > clay. For most cases, adding CG increased total water holding capacity (WHC). However, after WDC, the increase in water content at field capacity (FC) with CG was accompanied by a greater increase in wilting point (WP) and therefore a decrease in AW. CG improved soil structure and aggregation and increased non-water-stable aggregates in calcareous and clayey soils. Mean weight diameter (MWD) indicated increase in water-stable aggregates in sand at 5% and 10% CG. In clay, MWD increased only at 5% CG. Although results did not show coherent responses with some tested properties, they, mostly, indicate some beneficial effects of CG, particularly in relation to improving aggregation and water flow

STUDY OF THE ANTI-HYPERLIPIDEMIC EFFECT OF THE COMBINED ADMINISTRATION OF THREE NATURAL EXTRACTS IN A POLOXAMER-407 HYPERLIPIDEMIC MODEL AND THEIR LC-ESI-MS/MS2 AND HPLC PROFILING

Objective: Dyslipidaemia is considered a high-risk factor for inducing atherosclerosis and cardiovascular diseases (CVDs). This study aims to investigate the anti-hyperlipidemic effect of the co-administration of the ethanol extracts of both ginger (root and rhizome) and leek (leaves and bulbs) in addition to the aqueous extract of gum arabic.  Methods: Rats were divided into eight groups: Hyperlipidaemia was induced in rats by a single intraperitoneal injection of Poloxamer 407 (P-407) [1 g/kg], negative control [saline injected], hyperlipidemic control [P-407 injected], positive control [Atorvastatin 70 mg/kg], groups four, five and six received ginger extract (400 mg/kg), leek extract (500 mg/kg) and gum arabic aqueous extract (7.5 g/kg) respectively and groups seven and eight received a co-administration of ginger, leek and gum arabic extracts at doses A and B respectively. Lipid profile was monitored. The profiling of all the tested extracts was performed by LC-ESI/MS and HPLC. Results: A significant anti-hyperlipidemic activity (P<0.05) was seen for group eight among all the tested groups producing ≈54%, 72%, 50% and 72% decrease in the measured parameters total cholesterol (TC), triglycerides (TG), low-density lipoprotein (LDL) and very-low-density lipoprotein (VLDL) respectively. An overall of 56 and 45 compounds were tentatively identified in the ethanol extracts of ginger and leek, respectively. Galactose and arabinose sugars were found to be the major saccharides in gum arabic and glucuronic acid was the major polyuronide part. Conclusion: the co-administration of a group of natural extracts in the given concentration proved to be more effective than the use of synthetic drugs or the use of a single component.&nbsp