Investigation on the use of crumb rubber concrete (CRC) for rigid pavements

University of Technology Sydney. Faculty of Engineering and Information Technology.In many countries around the world, the adverse environmental impacts of stockpiling waste tyres have led to investigate alternative options for disposal of waste tyres. One option to reduce this environmental concern is for the construction industry to consume a high amount of recycled tyres accumulated in stockpiles. There are different concerns regarding the introduction of rubber into concrete, which were addressed by previous studies. On the one hand, making a homogenous mix containing even distribution of rubber is a challenge. On the other hand, the severe reduction of concrete strength limits the rubber content. Moreover, replacing a portion of fine aggregates with low-stiffness rubber particles raises concerns regarding the generated shrinkage and cracking of rubberised concrete. This thesis investigates these concerns thoroughly and provides a comprehensive know-how of rubberised concrete characteristics, using crumb rubber. In order to improve the strength of rubberised concrete different rubber treatment has been introduced by previous studies. A commonly applied rubber treatment method in the literature termed sodium hydroxide (NaOH) treatment has been assessed in this study. Numerous investigations examined using sodium hydroxide treatment of rubber. However, the level of improvement provided by different studies was not consistent. It was found that the sodium hydroxide treatment method is required to be optimised to achieve the most promising results. Two arrays of concrete specimens were prepared using different water cement ratios and a wide range of rubber contents. Then, the common fresh and hardened mechanical tests were conducted on the prepared samples. The results indicated that the duration of rubber treatment should be optimised based on concentration of the alkali solution and the type of recycled rubber. Consequently, the 24-hour treatment duration for crumb rubber resulted in the most suitable fresh and hardened concrete characteristics. Compared to untreated rubberised concrete, rubberised concrete produced with the optimised sodium hydroxide treated rubber, showed 25% and 5% higher compressive and flexural strength, respectively. Based on a large number of tests, this research introduced a relationship between the strength of rubberised concrete and three key parameters including the water-cement ratio (WC), the concrete age and the rubber content. Using this relationship enables concrete producers to have an accurate estimate of rubberised concrete strength. In addition, this research investigated the effects of applying an innovative method of rubber treatment, named “water-soaking”. Unlike the current methods of adding rubber into a concrete mix, which are conducted in a dry process, this research trialled introducing of rubber particles into the concrete mix in a wet process. Conducting the required sets of fresh and hardened concrete tests, number of mix series with a variety of rubber contents and water-cement ratios were evaluated. In order to measure the effectiveness of the introduced method, the properties of concrete containing water soaked rubber were compared with concrete containing untreated rubber. It was revealed that applying the proposed method resulted in considerable improvement of fresh and hardened properties. Applying the water-soaked method resulted in 22% higher compressive strength, and the formation of stronger bonds between rubber particles and cement paste compared to concrete made with untreated rubber. The effects of using recycled tyre rubber on shrinkage properties of rubberised concrete were evaluated. It was observed that adding rubber into a concrete mix led to minimise shrinkage cracks, if only an optimised content of rubber was applied. Therefore, the optimised rubber content was determined based on the mix design properties, the early-age tensile strength, and the results of plastic and drying shrinkage tests. Accordingly, the early-age mechanical strength tests, toughness test, bleeding test, and the plastic and drying shrinkage tests were conducted. A semi-automated image processing method of crack analysis was introduced in this research. Average cracks width, length, and area were determined accurately by applying the introduced method. In addition, the experimental data resulted from drying shrinkage tests of rubberised concrete were crosschecked with the results of numerical shrinkage formula provided in the Australian Standard AS3600. It was found that the provided relationship in the Australian Standard AS3600 is a valid measure for estimating the drying shrinkage of rubberised concrete. By considering the shrinkage characteristic and the acceptable mechanical performance of rubberised concrete, this dissertation concludes that the most promising results could be achieved for samples prepared with water-cement ratios of 0.45 and 0.40, and rubber contents of 20% and 25%, respectively

A capillary zone electrophoresis (CZE) method for the determination of cyclizine hydrochloride in tablets and suppositories

Current compendial methods of assay for the analysis of cyclizine tablets involve the use of UV spectrophotometry. Since this is a non-selective technique its application to more complex dosage forms, such as suppositories, is unlikely to be appropriate. There is therefore a need for the development of a highly specific quantitative analytical method, such as high performance liquid chromatography (HPLC) or capillary electrophoresis (CE). The latter technique was chosen in view of some specific advantages over HPLC, such as the use of relatively non-toxic aqueous buffers, as opposed to organic solvents, which obviates the use of expensive HPLC grade solvents making CE more cost effective. Cyclizine was analyzed in 50 mM phosphate buffer (pH 2.3) and run at an applied voltage 25 kV. Detection sensitivity was enhanced by using a wavelength of 200 nm and samples were loaded hydrodynamically onto an uncoated fused-silica capillary (60 cm×50 mm i.d.). Chlorcyclizine was used as the internal standard and resolution of both compounds was achieved in less than 7 min. Stress testing was undertaken in order to investigate the appearance of breakdown products. The method has the requisite accuracy, selectivity, sensitivity and precision to assay cyclizine in tablets and suppositories. Degradation products resulting from the stress studies did not interfere with the detection of cyclizine and the assay is thus stability-indicating

Health education effects on nutritional behavior modification in primary school students

چکیده: زمینه و هدف: تغذیه ناسالم در بروز بیماری‌هایی مانند بیماری قلبی و عروقی، سکته، انواع سرطان ها، دیابت، ناراحتی های گوارشی، انواع بیماری های استخوانی و مفاصل تأثیر به سزایی دارد. از آنجایی که ریشه اغلب رفتارهای غلط بهداشتی به تجارب دوران کودکی بر می گردد لذا پژوهش حاضر با هدف بررسی تأثیر آموزش بهداشت بر تغییر آگاهی و رفتارهای تغذیه ای دانش آموزان ابتدایی انجام گرفت. روش بررسی: پژوهش حاضر یک مطالعه نیمه تجربی (Quasi experimental) است که میزان آگاهی و عملکرد تغذیه ای دانش آموزان با استفاده از پرسشنامه سه قسمتی (مشخصات دموگرافیک، آگاهی و عملکرد) و چک لیست مشاهده مستقیم مورد بررسی و مقایسه قرار گرفت. تعداد 89 نفر از دانش آموزان پایه پنجم ابتدایی در سال 1384 در شهرستان قزوین به روش نمونه گیری خوشه ای برای شرکت در پژوهش در گروه مورد و 87 نفر نیز جهت گروه شاهد انتخاب شدند. پس از اجرای برنامه آموزش بهداشت برای گروه مورد که به دو روش مستقیم (حضوری و چهره به چهره همراه با پرسش و پاسخ) و غیر مستقیم (با استفاده از جزوه و سایر مواد آموزشی) و با توجه به نیازسنجی اولیه طراحی شده بود، میزان تأثیر آموزش بر آگاهی و عملکرد دانش آموزان مورد سنجش قرار گرفت. یافته ها: یافته های تحقیق نشان داد آگاهی دانش آموزان از 21/6±61/23 به 96/4±62/30 و عملکرد تغذیه ای آنها از 08/7±19/13 به 63/6±98/19 افزایش یافت (001/0

The effect of dietary regimen education on the laboratory variables and interdialytic weight gain in hemodialytic patients

چکیده: زمینه و هدف: تغذیه یک فاکتور مهم در درمان بیماران مبتلا به بیماری مزمن کلیوی می باشد، به طوری که رژیم غذایی نامناسب باعث کاهش کیفیت زندگی و افزایش مشکلات و ناخوشی و مرگ و میر در این بیماران می شود. این پژوهش با هدف بررسی تأثیر آموزش رژیم غذایی بر شاخص های آزمایشگاهی و اضافه وزن بین دو جلسه دیالیز در بیماران تحت درمان با همودیالیز نگه دارنده انجام شد. روش بررسی: یک مطالعه قبل و بعد که در یک گروه به صورت پیش آزمون - پس آزمون در بیمارستان های آموزشی منتخب دانشگاه های علوم پزشکی تهران و ایران انجام گرفت. 32 بیمار تحت درمان با همودیالیز نگه دارنده بصورت غیر تصادفی و مبتنی بر هدف انتخاب گردیدند و با استفاده از پرسشنامه تعیین نیازهای آموزشی مورد بررسی قرار گرفتند. شاخص های آزمایشگاهی به صورت میانگین دو ماهه قبل از آموزش و اضافه وزن بین دو جلسه دیالیز در 4 نوبت در طی دو هفته قبل از آموزش اندازه گیری شد. سپس یک برنامه آموزشی بر اساس مشکلات تعیین شده و الگوی خود مراقبتی اورم تدوین و در طی چهار جلسه 20 دقیقه ای در روزهایی که بیماران دیالیز نمی شدند، به صورت پرسش و پاسخ بین بیماران و آموزش دهنده با کمک وسایل کمک آموزشی (اورهد و پاورپوینت) ارائه گردید. بعد از پایان آموزش، شاخص های آزمایشگاهی به صورت میانگین دو ماهه بعد از آموزش و اضافه وزن بیماران در 4 نوبت به فاصله دو هفته بعد از آموزش (هفته های سوم و پنجم) اندازه گیری و با استفاده از آزمون t زوجی تجزیه و تحلیل شدند. یافته ها: نتایج نشان دهنده کاهش قابل توجهی در میزان اوره (001/0

A stability-indicating high performance liquid chromatographic assay for the determination of orlistat in capsules

A stability-indicating HPLC method was developed and validated for the quantitative determination of orlistat in capsule dosage forms. An isocratic separation was achieved using a Perfectsil® target ODS-3, 250 mm × 4.6 mm i.d., 5 µm particle size column with a flow rate of 0.7 ml/min and using a UV detector to monitor the eluate at 210 nm. The mobile phase consisted of methanol:acetonitrile:trifluoroacetic acid (82.5:17.5:0.01, v/v/v). The drug was subjected oxidation, hydrolysis, photolysis and heat to apply stress conditions. Complete separation was achieved for the parent compound and all degradation products in an overall analytical run time of approximately 15 min with the parent compound orlistat eluting at approximately 9 min. The method was linear over the concentration range of 0.02–0.75 mg/ml (r = 0.9998) with a limit of detection and quantitation 0.006 and 0.02 mg/ml, respectively. The method has the requisite accuracy, selectivity, sensitivity and precision to assay orlistat in capsules. Degradation products resulting from the stress studies did not interfere with the detection of orlistat and the assay is thus stability-indicating

Generation of circular polarization of the CMB

According to the standard cosmology, near the last scattering surface, the photons scattered via Compton scattering are just linearly polarized and then the primordial circular polarization of the CMB photons is zero. In this work we show that CMB polarization acquires a small degree of circular polarization when a background magnetic field is considered or the quantum electrodynamic sector of standard model is extended by Lorentz-noninvariant operators as well as noncommutativity. The existence of circular polarization for the CMB radiation may be verified during future observation programs and it represents a possible new channel for investigating new physics effects.Comment: 28 pages, v3, Phys. Rev. D 81, 084035 (2010

An LC-MS-MS method for the determination of cyclizine in human serum

Cyclizine is a piperazine derivative with anti-emetic activity that is useful in the prevention and treatment of nausea and vomiting associated with motion sickness. A liquid chromatography-tandem mass spectrometry (LC-MS-MS) method is presented for the quantitation of cyclizine in serum. Sample pretreatment involved liquid-liquid extraction of 200 μl of serum with dichloromethane after the addition of 100 μl each of ammonium hydroxide and internal standard solutions. The extracts were analyzed by HPLC on a Luna ® C18 reversed-phase column and an ion-trap mass spectrometer with an electrospray interface. A limit of detection of 1 ng/ml was determined which allowed for the reliable measurement of cyclizine in the serum of human subjects. The method was found to be linear over the calibration range of 2.5-100 ng/ml. The applicability of this method was demonstrated by the analysis of serum obtained from a human volunteer following administration of a single 50 mg cyclizine hydrochloride tablet. The reported method was observed to have the necessary sensitivity, selectivity, precision and accuracy for monitoring cyclizine concentrations in human subjects following oral administration

Nerve growth factor receptors in dementia

Background/aim: Nerve growth factor (NGF) promotes the survival and differentiation of sensory and sympathetic neurons. Several studies have found that certain neuropathological factors stimulate NGF receptor expression and release the truncated nerve growth factor receptor (TNGFR) to biological fluids. The aim of this pilot study was to determine urine TNGFR levels in patients with dementia and to verify whether TNGFR can be used as a biomarker of dementia. Materials and methods: Twelve patients with dementia and 12 healthy individuals were asked to voluntarily participate in this study. Ages, sexes, and weights were matched. The first morning urine samples were collected and the concentrations of TNGFR in the urine samples were measured by fluoroimmunoassay. Results: The mean levels of TNGFR in the urine samples of the healthy control subjects and the patients with dementia were 164 +/- 23 and 341 +/- 66 ng / mg creatinine respectively. A positive relationship was found between the levels of TNGFR in different ages of both control and patient subgroups. This is consistent with the previous observations that pathological condition may stimulate the NGF receptor expression. Conclusion: These findings might be of assistance to evaluate the development of the memory loss associated with Alzheimer disease and other age-associated diseases

Evaluating reliability and predictive validity of the persian translation of quantitative checklist for autism in toddlers (Q-CHAT)

Objective: Early screening of autism increases the chance of receiving timely intervention. Using the Parent Report Questionnaires is effective in screening autism. The Q-CHAT is a new instrument that has shown several advantages than other screening tools. Because there is no adequate tool for the early screening of autistic traits in Iranian children, we aimed to investigate the adequacy of the Persian translation of Q-CHAT. Method: At first, we prepared the Persian translation of the Quantitative Checklist for Autism in Toddlers (Q-CHAT). After that, an appropriate sample was selected and the check list was administered. Our sample included 100 children in two groups (typically developing and autistic children) who had been selected conveniently .Pearson's r was used to determine test-retest reliability, and Cronbach's alpha coefficient was used to explore the internal consistency of Q-CHAT. We used the receiver operating characteristics curve (ROC) to investigate whether Q-CHAT can adequately discriminate between typically developing and ASD children or not. Data analysis was carried out by SPSS 19. Result: The typically developing group consisted of 50 children with the mean age of 27.14 months, and the ASD group included50 children with the mean age of 29.62 months. The mean of the total score for the typically developing group was 22.4 (SD=6.26) on Q-CHAT and it was 50.94 (SD=12.35) for the ASD group, which was significantly different (p=0.00).The Cronbach's alpha coefficient of the checklist was 0.886, and test-retest reliability was calculated as 0.997 (p<0.01). The estimated area under the curve (AUC) was 0.971. It seems that the total score equal to 30 can be a good cut point to identify toddlers who are at risk of autism (sensitivity= 0.96 and specificity= 0.90). Conclusion: The Persian translation of Q-CHAT has good reliability and predictive validity and can be used as a screening tool todetect18 to 24 months old children who are at risk of autism

Analysis of stop-gain and frameshift variants in human innate immunity genes.

Loss-of-function variants in innate immunity genes are associated with Mendelian disorders in the form of primary immunodeficiencies. Recent resequencing projects report that stop-gains and frameshifts are collectively prevalent in humans and could be responsible for some of the inter-individual variability in innate immune response. Current computational approaches evaluating loss-of-function in genes carrying these variants rely on gene-level characteristics such as evolutionary conservation and functional redundancy across the genome. However, innate immunity genes represent a particular case because they are more likely to be under positive selection and duplicated. To create a ranking of severity that would be applicable to innate immunity genes we evaluated 17,764 stop-gain and 13,915 frameshift variants from the NHLBI Exome Sequencing Project and 1,000 Genomes Project. Sequence-based features such as loss of functional domains, isoform-specific truncation and nonsense-mediated decay were found to correlate with variant allele frequency and validated with gene expression data. We integrated these features in a Bayesian classification scheme and benchmarked its use in predicting pathogenic variants against Online Mendelian Inheritance in Man (OMIM) disease stop-gains and frameshifts. The classification scheme was applied in the assessment of 335 stop-gains and 236 frameshifts affecting 227 interferon-stimulated genes. The sequence-based score ranks variants in innate immunity genes according to their potential to cause disease, and complements existing gene-based pathogenicity scores. Specifically, the sequence-based score improves measurement of functional gene impairment, discriminates across different variants in a given gene and appears particularly useful for analysis of less conserved genes