1,276 research outputs found

    Comment on "Head-on collision of electron acoustic solitary waves in a plasma with nonextensive hot electrons"

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    In a recent paper "Head-on collision of electron acoustic solitary waves in a plasma with nonextensive hot electrons" [Astrophys. Space Sci. 338, 271-278 (2012)] Eslami, Mottaghizadeh and Pakzad deal with the problem of the head-on collisions between two weakly nonlinear electron-acoustic solitary waves. Unfortunately, their treatment is deficient and leads to erroneous conclusions.Comment: Accepted for publication in "Astrophysics and Space Science

    The effect of individual counseling, line follow-up, and free nicotine replacement therapy on smoking cessation in the samples of Iranian smokers: Examination of transtheoretical model

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    Background: According to transtheoretical model(TTM), Stage matched interventions are more effective in quitting. The objective of current study was to investigate the effect of individual counseling, line follow-up, and free nicotine replacement therapy(NRT) on smoking cessation in smokers who are in preparation stage of smoking. Materials and Methods: In a randomized clinical trial design, through sending the short message system, potential participants in preparation stage of smoking were recruited and divided into control(n=60)and treatment(n=50) groups. The treatment group received an in-person counseling, line follow-up, and free NRT. TTM variables trend; pros and cons of smoking, behavioral and experiential processes, temptation, were assessed at baseline, 3 and 6months follow-up along with point prevalence and continuous abstinence. Results: Continuous abstinence at 6-month follow-up were 3.3%(n=2) in control group and 46%(n=23) in the treatment group(x 2 = 34.041, P < 0.001). Time � group analyses indicated that except cons of smoking (P > 0.05), all TTM constructs had significantly changed; temptation(F=36.864, P<0.001), pros (F=12.172, P<0.001), experiential processes(F=3.377, P<0.001), and behavioral processes(F=11.131, P<0.001). Conclusion: Interventions based on TTM variables increased the quite rate in prepared and motivated people. Our findings suggest that interventions through individual counseling along with free NRT and line follow-up in people who prepare for quitting are beneficial for our country

    Extreme bendability of DNA double helix due to bending asymmetry

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    Experimental data of the DNA cyclization (J-factor) at short length scales, as a way to study the elastic behavior of tightly bent DNA, exceed the theoretical expectation based on the wormlike chain (WLC) model by several orders of magnitude. Here, we propose that asymmetric bending rigidity of the double helix in the groove direction can be responsible for extreme bendability of DNA at short length scales and it also facilitates DNA loop formation at these lengths. To account for the bending asymmetry, we consider the asymmetric elastic rod (AER) model which has been introduced and parametrized in an earlier study (B. Eslami-Mossallam and M. Ejtehadi, Phys. Rev. E 80, 011919 (2009)). Exploiting a coarse grained representation of DNA molecule at base pair (bp) level, and using the Monte Carlo simulation method in combination with the umbrella sampling technique, we calculate the loop formation probability of DNA in the AER model. We show that, for DNA molecule has a larger J-factor compared to the WLC model which is in excellent agreement with recent experimental data.Comment: 8 pages, 9 figure

    Economic evaluation of municipal solid waste recycling in Yazd: Cost-benefit analysis

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    Background and aims: In every urban waste management plan, recycling and reuse is considered as an economic pattern. This study aimed to economic evaluation of municipal solid waste recycling in Yazd by cost-benefit analysis in 2015. Methods: This research is a descriptive–analytic study which in the data about quality and quantity of municipal solid waste in Yazd city were collected through the sampling and physical analysis and the data about total income and costs from the implementation of waste separation and recycling were collected by interview with recovery officials and field observations and were analyzed through the economic analysis of the cost-benefit. Results: The results indicated that the mean of waste produced annually in Yazd city was 109679.51 tons per years. The percentage of municipal waste components was organic matter (67%), plastics (7%), paper and cardboard (5%), metals (2%), wood (2%), glass (2%), leather and rubber (1%), textiles (1%) and PET containers (1%), respectively. Also, Only 2 percent of total daily production of waste were separated and recycled at source. The implementation a cost of waste separation at source on a monthly basis was 768,880,000 Rails and the benefits of it was 904,667,400 Rails and as a result, the amount of net benefit derived from the recycling scheme was 135,787,400 Rails. Conclusion: Considering the economic benefits of waste separation and recycling at source in the city of Yazd, can be in addition to compensate the many of the waste management sector costs and reduced waste disposal and management costs, Preventing environmental degradation and pollution of water, soil and air resources
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