Investigating the potential of using acoustic frequency on the degradation of linear alkylbenzen sulfonates from aqueous solution

The effectiveness of using acoustical (sonochemical) reactor for degradation of linear alkylbenzen sulfonate (LAS) from aqueous solution was investigated. LASs are anionic surfactants,found in relatively high amounts in domestic and industrial wastewaters. In this study,experiments on LAS solution were performed using methylene blue active substances (MBAS) method. The effectiveness of acoustical processor reactor for LAS degradation is evaluated with emphasis on the effect of treatment time and initial LAS concentration. Experiments were performed at initial concentrations of 0.2,0.5,0.8 and 1.0 mg/L,acoustic fre-quency of 130 kHz,applied power of 500 W and temperature of 18 °C～20 °C. At the conditions involved,LAS degradation was found to increase with increasing sonochemical time. In addition,as the concentration increased,the LAS degradation rate de-creased in the acoustical processor reactor.     

Symmetry properties of tetraammine platinum(II) with C_(2v) and C_(4v) point groups

INTRODUCTION The simplicity and elegance of some of theapplications of graph theory to chemistry can perhapsonly be compared with the results from group theorydealing with symmetry as a basic quality of a system.In some problems connectivity and symmetry arecombined and the question of determining symmetryproperties of graph becomes important. Given here are some definitions and notations.An automorphism of a graph G is a permutation g ofthe vertex set of G with the property that, for an…     

Note on the expansion of higher education in Bahrain

This article deals with the development of higher education in Bahrain. The study includes the philosophy of the educational system which co-relates religious morals and cultural traditions with modern economics, technological and scientific developments. Empirical statistics show the growth of higher education in Bahrain since the late sixties. In 1968, the strength of staff and students was 3 and 18 respectively. This has grown to 469 staff members and 5633 students by 1987.     

The Boundary Between Finite and Infinite States Through the Concept of Limits of Sequences

In this article, attempts were made to examine students’ thinking about the concepts of infinity and their ideas about transiting from finite to infinite states through the concept of limits of sequences. The participants included 78 senior high-school students ranging in age between 17 and 19 years old. The data were collected through a questionnaire and an interview with all of the subjects. The findings showed that the students’ understanding of infinity is related to finite situations and many students consider infinite processes as a generalized form of finite processes. In the present study, the most common mistakes committed by students were related to consideration of infinity as a number and application of known finite results to infinite states.     

Renovation of Adult Education by the New Media

In most developing countries, that are confronted, as we know, with so many complex problems, no one can deny that the most important are those of education and training.     

Effect of telenursing on aging perception of Iranian older adults

Background and purpose: The perception of aging is one of the independent predictors of functional disability and mortality in the aged ones, this study was conducted to compare the follow-up of a training program with the use of two in-person and telenursing methods on the perception of aging of the elderly, covered by the comprehensive health centers in Ahvaz city.

Materials and Methods: This quasi-experimental study involved systematic random sampling conducted on 60 elderly persons (aged 60–75 years) who were referred to in Ahvaz. A training program was conducted for all elderly persons for 3 weeks (three sessions per week), which was accompanied with 2 months of six follow-ups for the telephonic follow-up group (Tele-nursing), and two follow-ups for in-person follow-up group. The data were collected with the use of demographic form, Abbreviated Mental Test (AMT), and The Brief Aging Perceptions Questionnaire (B-APQ). Elderly completed the questionnaire at the beginning of the study and 8 weeks later. The data were subsequently analyzed with SPSS software; and P values less than 0.05 were considered significant.

Results: Based on the results, the mean score of perception of aging increased in the study groups after the intervention. This increase was statistically significant only in the intervention group.

Discussion and Conclusion: The telephonic follow-up was more effective on Increasing the perception of aging compared with the in-person follow-up. Therefore, using this method is recommended for the elderly.     

The degree to which UAE primary science workbooks promote scientific inquiry

This research investigated Grades 5 and 6 science workbooks for the degree to which they promote scientific inquiry abilities, opportunities that students had to acquire these abilities and the obstacles hindering students from implementing them. A document review technique and a constant comparative method were applied sequentially. A total of 58 instigative logs were scrutinized. Findings revealed that while the activities allowed students to use appropriate techniques and tools to collect and interpret data, and use their inquiry abilities related to implement investigation plans, they did not allow students real opportunities to formulate questions, plan for simple investigations, write conclusions, or communicate investigations. A total of 15 Grade 5 and 6 science teachers were asked to report their perceptions of the students’ role in implementing identified abilities. A one‐way analysis of variance revealed that there was a significant difference between students who individually implemented the inquiry abilities and students who were supported by the teacher or by other students. Obstacles that hindered students from implementing identified inquiry abilities included teachers’ intensive supports, students’ limited background or skills, and materials and instrument shortages. The study concluded with recommendations for policy, practice, and future research.     

Graduated compression stockings: Physiological and perceptual responses during and after exercise

Abstract

The aim of this study was to examine the effect of wearing graduated compression stockings on physiological and perceptual variables during and after intermittent (Experiment 1) and continuous (Experiment 2) running exercise. Fourteen recreational runners performed two multi-stage intermittent shuttle running tests with 1 h recovery between tests (Experiment 1). A further 14 participants performed a fast-paced continuous 10-km road run (Experiment 2). Participants wore commercially available knee-length graduated compression stockings (pressure at ankle 18 – 22 mmHg) beneath ankle-length sports socks (experimental trials) or just the latter (control trials) in a randomized counterbalanced design (for both experiments). No performance or physiological differences were observed between conditions during intermittent shuttle running. During the 10-km trials, there was a reduction in delayed-onset muscle soreness 24 h after exercise when wearing graduated compression stockings (P < 0.05). There was a marked difference in the frequency and location of soreness: two participants in the stockings trial but 13 participants in the control trial indicated soreness in the lower legs. Wearing graduated compression stockings during a 10-km road run appears to reduce delayed-onset muscle soreness after exercise in recreationally active men.     

Carbohydrate ingestion and soccer skill performance during prolonged intermittent exercise

Abstract

The aim of this study was to investigate the effect of ingesting a carbohydrate-electrolyte solution, during the 90-min Loughborough Intermittent Shuttle Test, on soccer skill performance. Seventeen male soccer players ingested either a 6.4% carbohydrate-electrolyte solution or placebo solution equivalent to 8 ml · kg^?1 body mass before exercise and 3 ml · kg^?1 body mass after every 15 min of exercise, in a double-blind randomized cross-over design, with the trials separated by 7 days. The evening before the main trial, the participants performed glycogen-reducing exercise on a cycle ergometer (80 min at 70%[Vdot]O_2max) and were then fed a low-carbohydrate meal. After a 12-h overnight fast, they performed The Loughborough Soccer Passing Test before and after every 15 min of exercise. Analysis of the combined skill test data showed a significant time effect (P = 0.001) with differences between 0–45 and 75–90 min (P < 0.05). There was a 3% reduction in skill performance from before to after exercise in the carbohydrate-electrolyte trial, whereas in the placebo trial the decrease was 14% (P = 0.07). In conclusion, skill performance during the simulated soccer activity appeared to deteriorate in the last 15–30 min of exercise. However, providing 52 g · h^?1 carbohydrate during exercise showed a tendency to better maintain soccer skill performance than a taste-matched placebo.