Investigation of Internal Erosion Susceptibility of Core Soil from Three Dams

Laboratory tests on internal erosion of cohesionless soils are often performed on cells submitted to a controlled seepage. The cell dimension depends on the grain size of tested soil and must meet the geometric and hydraulic scale requirements as regards to the modeled process. Three specimens collected from different zoned dams in Morocco were characterized for their geotechnical properties and dispersion sensitivity, and then submitted in two different cells to internal erosion (Hole Erosion Test) under controlled seepage. The erosion kinetics was measured, and soil classification was assessed as regards to the useful engineering guidelines. The results showed that specimen dimensions can affect the erosion parameters which are quite different from a cell to another. Even though the derived erosion coefficient values are different from the two testing cells, the classification of the three soils regarding the susceptibility to erosion, using engineering guidelines, indicated that the tested soils fall overall in neighboring erosion classifications. However, the soil involving the lower clay content provided the greatest resistance against internal erosion

Perceived oral health among adults in Tehran, Iran; a telephone survey

Objective: In comparison to clinical oral health indices, perceived oral health measures are less applied in large-scale epidemiological oral health studies in Iran. The aim of this study was to measure perceived oral health among adults in Tehran, Iran.Methods: In this cross-sectional study, perceived oral health was measured in 1100 adults in Tehran by two measures: 1- non-replaced extracted teeth, and 2- revised Rand dental health questions including pain, chewing problems and communication problems. Data was gathered by telephone interview using gender, age and level of education as socio-demographic information.Results: The mean number of non-replaced extracted teeth was 1.28 with 53.8% of adults reporting no extracted teeth. Extracted teeth was significantly less in younger (p<0.001) and more educated people (p<0.001). Rand dental health scores increased by age (p<0.001) but had no significant changes in different educational levels. The three items of Rand dental health were highly correlated (p<0.01) with Chronbach’s Alpha=0.73 but were not correlated with extracted teeth.Conclusion: Approximately half of Tehran adults have the experience of lacking one or more teeth, with a small group of them suffering from pain, chewing problems and communication problems

DEFLUORIDATION OF DRINKING WATER BY ELECTROCOAGULATION/ELECTROFLOTATION - KINETIC STUDY

A variable order kinetic (VOK) model derived from the langmuir-freundlish equation was applied to determine the kinetics of fluoride removal reaction by electrocoagulation (EC). Synthetic solutions were employed to elucidate the effects of the initial fluoride concentration, the applied current and the initial acidity on the simulation results of the model. The proposed model successfully describes the fluoride removal in Airlift reactor in comparison with the experimental results. In this study two EC cells with the same capacity (V = 20 L) were used to carry out fluoride removal with aluminum electrodes, the first is a stirred tank reactor (STR) the second is an airlift reactor (ALR). The comparison of energy consumption demonstrates that the (ALR) is advantageous for carrying out the defluoridation removal process

Effects of Smoking Cessation Counseling Based on the Stages of Change Model in a Dental School Setting: A Semi-Experimental Study

Objectives The present study aimed to evaluate the effects of smoking cessation counseling by a dentist on the smokers’ preparation for change to quit smoking. Methods This study was performed on 150 smokers, admitted to the Dental School of Shahid Beheshti University of Medical Sciences, Tehran, Iran. The patients were randomly divided into two groups of 75 participants. The intervention group received smoking cessation counseling by a single senior dental student for 30 min session. The patient’s status in the stages of change was determined at baseline and after the intervention. For statistical analysis, paired t-test, Mann-Whitney U test, and multivariate linear regression analysis were performed at a significance level of P<0.05. Results At baseline, there were no significant differences between the intervention and control groups in terms of the stage of change for smoking cessation. Also, there was no significant difference in the stages of change in the control group between the baseline and one-month follow-up. However, this difference was significant in the intervention group (P=0.006). In other words, the number of patients in the pre-contemplation stage decreased by 43%, the number of patients in the contemplation stage increased by 20%, and the number of patients in the action stage increased by 16%. Conclusion It can be concluded that smoking cessation counseling enhances a person’s forward movement and transition through the stages of change for smoking cessatio

Design and Development of a Litho-code ID based electronic entry-control system

Different card operated entry control systems have been developed. However, it is desired that the system is reliable, easy to implement and available at market. In this paper, we design and develop an electronic entry control system which is based on an ID card and ID card reader. In our system, the ID card contains encoded Litho-code ID and the card reader is used to read the encoded ID. We develop offline Software to collect user information, save data and to print the ID card. We design and develop the electronic card reader to capture the ID using infra-red (IR) sensors and for computer interfacing. We develop online software to process the signals exchanged between the card reader and CPU. In this paper, first we present the system layout and design outline. Then we explain the development and implementation methodology. Finally, we test the system and present the results.DOI:http://dx.doi.org/10.11591/ijece.v2i4.70

Dental Residents’ Knowledge and Attitude towards Stem Cells and Regenerative Dentistry

Objectives: Success of regenerative dental procedures highly depends on their acceptance by the clinicians; yet, little is known about dental residents’ attitudes regarding this new technology. The purpose of this study was to assess the knowledge and attitude of post-graduate dental students towards stem cells and regenerative dentistry as part of future dental treatments.Methods: This cross-sectional survey was conducted on 84 third-year residents of various dental specialties. The questionnaire included demographics and professional status of the respondents, questions regarding their ethical beliefs and their clinical practice.Results: Eighty-four completed questioners were returned anonymously. The majorities of the participants were female, and had practiced for ≤ 5 years. The survey showed that 76.2% of the participants had not received any continuing education or training courses on stem cells or regenerative dentistry. The majority of the participants (82.1%) believed that regenerative treatments should be included in dental practice. Of all, 76.2% had no umbilical cord or stem cell banking for themselves or a relative and 63.1% thought that dental pulp stem cell banking would be useful to regenerate dental tissues. Most of the participants (65.5%) had never performed regenerative therapy of any kind in their clinical practice and 51.2% of the participants were not sure whether regenerative procedures would be successful.Conclusion: Although more evidence on the efficacy and safety of regenerative dentistry is required, postgraduate training in this regard seems necessary