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In the present work, a novel nanofiber-based filter has been presented which is comprised of composite nanofibers of polyamide-66 and TiO2 nanoparticles (PA-66/TiO2) for trapping cement dust. The produced nanofibers under optimum conditions were characterised by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). The effect of some important electrospinning process parameters on the obtained electrospun nanofibers including solution concentration, flow rate, voltage‚ tip to collector distance and the presence of salt was investigated. Studies showed that the solution concentration of 15 wt. % of PA-66 resulted in thinner and smother nanofibers than the other solution concentrations and also the average diameter of the electrospun nanofibers was decreased with increasing 1 wt. % salt to the polymer solution. The produced nanofiber-based filter can be applied for capturing cement dust with a good filtration efficiency of 97% for 3–500 nm particles and a quality factor in the range of 0.069–0.034 Pa−1 [ABSTRACT FROM AUTHOR]

In the present work, a simple procedure is presented for the extraction and determination of pre-concentrated trace amounts of palladium ions through solid phase extraction (SPE) and flame atomic absorption spectrophotometry. This process was performed using Nylon-66/5-(4-dimethylaminobenzylidene) rhodanine composite nanofibres. These nanofibres were produced under optimised conditions via two-axial electrospinning technique and characterised by scanning electron microscopy and Fourier-transform infrared spectroscopy. The effect of experimental parameters including solution pH, the type and volume of eluent and contact time was investigated in extraction and desorption process. Under the optimised conditions, good linearity in the range of 0.07–8 μg L−1 and low detection limit of 0.015 μg L−1 were obtained. High enrichment factor of 187.5 and good relative standard deviation of ±2.2% at 5 μg L−1 of palladium had been achieved. The sorbent capacity for palladium adsorption was obtained 27 mg palladium per gram of nanofibres. So, the SPE was successfully applied to pre-concentrate and determine Pd(II) ions with flame atomic absorption spectrophotometer in real samples. [ABSTRACT FROM AUTHOR]

The Covid-19 has presented an unprecedented challenge to public health worldwide. However, residents in different countries showed diverse levels of Covid-19 awareness during the outbreak and suffered from uneven health impacts. This study analyzed the global Twitter data from January 1st to June 30th, 2020, to answer two research questions. What are the linguistic and geographical disparities of public awareness in the Covid-19 outbreak period reflected on social media? Does significant association exist between the changing Covid-19 awareness and the pandemic outbreak? We established a Twitter data mining framework calculating the Ratio index to quantify and track awareness. The lag correlations between awareness and health impacts were examined at global and country levels. Results show that users presenting the highest Covid-19 awareness were mainly those tweeting in the official languages of India and Bangladesh. Asian countries showed more disparities in awareness than European countries, and awareness in Eastern Europe was higher than in central Europe. Finally, the Ratio index had high correlations with global mortality rate, global case fatality ratio, and country-level mortality rate, with 21-31, 35-42, and 13–18 leading days, respectively. This study yields timely insights into social media use in understanding human behaviors for public health research. [ABSTRACT FROM AUTHOR]

Microwave-assisted distillation (MAD) is a combination of microwave heating and dry distillation at atmospheric pressure in which isolation and concentration of volatile compounds are carried out, simultaneously without solvent or water. The aim of this work is to evaluate the performance of MAD when isolating the essential oil ofRosa damascenaMill. For this purpose, first, two main parameters, namely extraction time and microwave power, which affect the efficiency of the extraction, were optimized. Then, to demonstrate the feasibility of the method, oil obtained under optimal conditions was compared quantitatively and qualitatively with that obtained by conventional hydrodistillation (HD) using an electric mantle heater. Considering the extraction yield, optimal extraction time and microwave power were obtained to be 15 minutes and 650 W, respectively. Extraction of essential oil from rose flowers with MAD offers important advantages over traditional HD in terms of energy saving, extraction time (15 minutes versus 3.5 hours) and extraction yield (0.037% versus 0.018%). However, there is a significant decrease in monoterpene alcohol percentages and increase in hydrocarbon percentages, which is a disadvantage from qualitative point of view. [ABSTRACT FROM PUBLISHER]

Immersive technologies are transforming all aspects of daily life. In educational context, augmented reality (AR) and virtual reality (VR) offer the promise of experiential learning, where the real world is enhanced with information and graphics or is completely simulated. The project described in this paper, builds on advances of these technologies to develop, implement, and test "Skope," a prototype immersive learning environment. Skope is designed to facilitate interdisciplinary education of architecture, engineering, and construction (AEC) students for design and construction of environmentally sustainable buildings. The Skope learning environment is comprised of an AR and a VR visualization tool as well as learning modules that contain interdisciplinary content. Skope is implemented and tested in three interdisciplinary AEC classes. Quantitative and qualitative analyses of student performance in these classes suggest that Skope has a positive impact and increased students' motivation and understanding of building science principles, ultimately leading to an improvement of learning across domains. In addition, findings of this research indicate that using Skope improves students' attitude toward collaborative learning. [ABSTRACT FROM AUTHOR]

Rosa damascenaMill. is the most important Rosa species for rose oil, concrete and absolute production. In the factories, petals of rose are harvested and distilled to produce rose oil and rose water. Distilled petals are wasted and don’t have any usage. Therefore, the purpose of the present work was to use fresh and, for the first time, distilled petals to produce concrete by Soxhlet method. Then the components of obtained concretes were analyzed by capillary gas chromatography-mass spectrometry (GC-MS) and compared with the concrete of Turkey. Results indicated that, concretes of fresh and distilled petals of Lalehzar of Kerman have 0.5 % and 0.25 % content, respectively. In attention to the content of 2-phenylethanol (36.28 %, 15.48 %), and long-chain hydrocarbons such as nonadecane (9.20 %, 11.18 %), nonadecene (1.84 %, 2.15 %), eicosane (1.37 %, 1.86 %) and heneicosane (7.70 %, 8.81 %) in the concretes of fresh and distilled petals respectively, concrete of distilled rose flowers is as a new product. [ABSTRACT FROM AUTHOR]

In the present study, multiwalled carbon nanotubes (MWCNTs) as solid phase extraction sorbent were developed for preconcentration of arsenic(V) species prior to graphite furnace atomic absorption spectrometry (GFAAS) determination. Arsenic(V) was selectively sorbed on the packed column with MWCNTs within a pH 9.5 in the presence of 2-(5-bromo-2-pyridylazo)-5-diethyl amino phenol (5-Br-PADAP). The adsorbed species was then desorbed with 1 mL of 2.0 M HNO3. Experimental parameters including pH, sample volume and flow rate, type, volume and concentration of eluent that influence the recovery of the arsenic(V) species were optimised. Under the optimised conditions, the calibration curve was linear in the range of 0.2–10.0 µg L−1with detection limit of 0.016 µg L−1. The relative standard deviations (RSD) for seven replicate determinations at 1.0 µg L−1level of arsenic was 6.69%. The proposed method was successfully applied to the determination of arsenic in water samples and certified reference material (NIST RSM 1643e). [ABSTRACT FROM AUTHOR]

Objective: Zinc is found in abundance in the human brain. Patients with depression may have decreased consumption of food sources rich in zinc, and zinc supplementation may have a potential influence on depressive symptoms. However, clinical trials on the effect of zinc supplementation in depression are limited. The objective of the present study was to determine the effect of zinc supplementation on efficacy of antidepressant therapy. Furthermore, the effect of zinc on plasma levels of interleukin-6 (IL-6), tumor necrosis factor (TNF-α), and brain-derived neurotrophic factor-a (BDNF-α) were assessed. Design: A single-center, randomized, double-blind, placebo-controlled trial of zinc supplementation was conducted in patients with DSM-IV major depression. Forty-four patients of both sexes aged 18-55 years were recruited for this study from a university hospital. The zinc-supplemented group received zinc sulfate (25 mg elemental Zn/day) orally in addition to their selective serotonin reuptake inhibitor antidepressants for 12 weeks. Symptoms were evaluated using the Hamilton Depression Rating Scale (HDRS) on arrival, weeks 6 and 12. Plasma levels of IL-6, TNF-α and BDNF-a were measured at baseline and at the end of study. Results: Twenty patients in zinc group and 17 patients in placebo groups completed the study. At baseline, there were no significant differences in any variable between the patients allocated to receive placebo and those taking zinc supplement. Zinc supplementation significantly reduced HDRS compared to placebo (P < 0.01 at 12th week). No significant differences were observed in plasma levels of IL-6, TNF-α, and BDNF-a between zinc-supplemented and placebo-supplemented group. Conclusion: Zinc supplementation in conjunction with antidepressant drugs might be beneficial for reducing depressive symptoms. However, its effect does not appear to be mediated through impact of zinc on inflammatory processes. [ABSTRACT FROM AUTHOR]