184 research outputs found

    The cosmological bulk flow in QCDM model: (In)consistency with ΛCDM\Lambda CDM

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    We study the bulk flow of the local universe using Type Ia supernova data by considering a class of cosmological model which is spatially flat,(FRW) space-times and contains cold dark matter and QQ component (QCDM models) of the fluid as a scalar field, with self interactions determined by a potential V(Q)=V0Exp(λQ)V(Q)=V_{0}Exp(-\lambda Q) evolving in Universe. We use different cumulative redshift slices of the Union 2 catalogue. A maximum-likelihood analysis of peculiar velocities confirms that at low redshift 0.015<z<0.10.015 <z<0.1, bulk flow is moving towards the (l;b)=(302o±20o;3o±10o)(l; b) = (302^{o}\pm20^{o}; 3^{o}\pm10^{o}) direction with vbulk=240±25kms1v _{bulk} = 240\pm 25kms^{-1} velocity. This direction is aligned with direction of (SSC) and agreement with a number previous studies at (1σ)(1-\sigma), however for high redshift 0.1<z<0.20.1 <z<0.2, we get vbulk=1000±25kms1v _{bulk} = 1000\pm 25kms^{-1} towards the (l;b)=(25414o+16o;610o+7o)(l; b) = (254^{+16^{o}}_{-14^{o}}; 6^{+7^{o}}_{-10^{o}}). This indicates that for low redshift our results are approximately consistent with the ΛCDM\Lambda CDM model with the latest WMAP best fit cosmological parameters however for high redshift they are in disagreement of ΛCDM\Lambda CDM and support the results of previous studies such as Kashlinsky et. al, which report the large bulk flow for the Universe. We can conclude that, in QCDMQCDM model, at small scales, fluctuations of the dark energy are damped and do not enter in the evolution equation for the perturbations in the pressureless matter, while at very large scales (>100h1Mpc)(\sim > 100 h^{-1}Mpc), they leaving an imprint on the microwave background anisotropy

    Photometric Stereo with Non-Lambertian Preprocessing and Hayakawa Lighting Estimation for Highly Detailed Shape Reconstruction

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    In many realistic scenarios, the use of highly detailed photometric 3D reconstruction techniques is hindered by several challenges in given imagery. Especially, the light sources are often unknown and need to be estimated, and the light reflectance is often non-Lambertian. In addition, when approaching the problem to apply photometric techniques at real-world imagery, several parameters appear that need to be fixed in order to obtain high-quality reconstructions. In this chapter, we attempt to tackle these issues by combining photometric stereo with non-Lambertian preprocessing and Hayakawa lighting estimation. At hand of a dedicated study, we discuss the applicability of these techniques for their use in automated 3D geometry recovery for 3D printing

    The Prevalence of Needle sticks injuries among health care workers at a hospital in Tehran

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    ABSTRACT Needle stick injuries (NSIs) are one of the most significant and preventable hazards in relation to Healthcare workers (HCWs). Such injuries have been shown to be of high prevalence within developing countries. To determine the prevalence and circumstances pertaining to the occurrence of NSIs among HCWs employed at a special hospital. The study conducted was a cross-sectional study on HCWs and was carried out in one of Tehran's special hospitals in the year 2012. In this study, in order to identify and determine hazardous potential due to needle stick, HFMEA method was chosen. This resulted in the collection of 240 valid and reliable questionnaires. The validity and reliable nature of the questionnaires was confirmed by experts and by means of the test re-test method. The gathered data was analyzed with SPSS software, version 16.From the analysis of the data it was shown that, a total of 97 (40.42%) HCWs had suffered NSIs in the last year. The patient ward showed the highest prevalence of NSIs (47.42%) in the hospital. Nurses had the highest risk of suffering NSIs (56.7%) in comparison with the other occupational groups. All in all 175 NSIs occurred for the 240 HCWs trialed during the selected period of clinical practice. Of those that received injuries, only roughly 1 in 3 (38.14%) reported it to their infection control officer. Just over a quarter (26.80%) of the injured HCWs used post exposure prophylaxis (PEP) against HIV. Almost all (88.75%) of the HCWs had received a safe injection course. In general, NSIs and their subsequent underreporting are commonplace among hospital healthcare professionals. Significantly, more than two-thirds of the injured HCWs did not use post-exposure prophylaxis (PEP) against HIV. Improved prevention and reporting strategies are needed if the occupational health and safety of healthcare workers is to improve

    Effect of TiO2-ZnO/GAC on by-product distribution of CVOCs decomposition in a NTP-assisted catalysis system

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    In this study, the catalytic effect of TiO2-ZnO/GAC coupled with non-thermal plasma was investigated on the byproducts distribution of decomposition of chlorinated VOCs in gas streams. The effect of specific input energy, and initial gas composition was examined in a corona discharge reactor energized by a high frequency pulsed power supply. Detected by-products for catalytic NTP at 750 J L-1 included CO, CO2, Cl2, trichloroacetaldehyde, as well as trichlorobenzaldehyde with chloroform feeding, while they were dominated by CO, CO2, and lower abundance of trichlorobenzaldehyde and Cl2 with chlorobenzene introduction. Some of the by-products such as O3, NO, NO2, and COCl2 disappeared totally over TiO2-ZnO/GAC. Furthermore, the amount of heavy products such as trichlorobenzaldehyde decreased significantly in favor of small molecules such as CO, CO2, and Cl2 with the hybrid process. The selectivity towards COx soared up to 77 over the catalyst at 750 J L-1 and 100 ppm of chlorobenzene. © by Farshid Ghorbani-Shahna 2015

    Characterization of radio active aerosols in Tehran research reactor containment

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    The objectives of this research were to determine the levels of radioactivity in the Tehran research reactor containment and to investigate the mass-size distribution, composition, and concentration of radio nuclides during operation of the reactor. A cascade impactor sampler was used to determine the size-activity distributions of radioactive aerosols in each of the sampling stations. Levels of α and β activities were determined based on a counting method using a liquid scintillation counter and smear tests. The total average mass fractions of fine particles (particle diameter dp &lt;1 µm) in all of the sampling stations were approximately 26.75 , with the mean and standard deviation of 52.15 ± 19.75 µg/m3. The total average mass fractions of coarse particles were approximately 73.2, with the mean and standard deviation of 71.34 ± 24.57 µg/m3. In addition to natural radionuclides, artificial radionuclides, such as 24Na,91Sr,131I,133I,103Ru,82Br, and 140La, may be released into the reactor containment structure. Maximum activity was associated with accumulation-mode particles with diameters less than 400 nm. The results obtained from liquid scintillation counting suggested that the mean specific activity of alpha particles in fine and coarse-modes were 89.7 and 10.26 , respectively. The mean specific activity of beta particles in fine and coarse-modes were 81.15 and 18.51 , respectively. A large fraction ofthe radionuclides' mass concentration in the Tehran research reactor containment was associated with coarse-mode particles, in addition, a large fraction of the activity in the aerosol particles was associated with accumulation-mode particles. © 2015, Vinca Inst Nuclear Sci. All rights reserved

    Spatial and temporal trends of short-term health impacts of PM2.5in Iranian cities; A modelling approach (2013�2016)

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    Estimation of the spatial and temporal trends of health impacts attributable to air pollution is an effective measure for evaluating implemented interventions. The aim of this study was to estimate the short-term mortality attributable to exposure to PM2.5among individuals older than 30 years old in ten Iranian cities from March 2013 to March 2016 using the World Health Organization�s (WHO) AirQ+ software. Hourly concentrations of PM2.5were acquired from the Department of Environment and Tehran Air Quality Control Company. Only stations with 75 and 50 of valid data were qualified for Tehran and other cities, respectively. The annual average PM2.5concentrations in all ten of the cities were higher than the WHO guideline value of 10 µg m�3The total number of attributable short-term deaths during the three-year period in these 10 cities was 3284 (95 CI: 1207�5244). The average daily premature deaths were calculated to be 3. The highest number of premature deaths within the three-year period was estimated to be 548 in Tehran, largely reflecting its population of nearly 9 million. The western and southern cities of Iran experience severe dust storms and showed a high estimated rate of death attributed to air pollution. The health impacts in all cities decreased in the third year compared to the first year except for Ahvaz, Khoram Abad, and Ilam. Governmental interventions need to be enforced more effectively to reduce the high level of adverse health impacts in Iran. Special considerations should be given to the air quality of cities affected by dust storms. © Taiwan Association for Aerosol Research

    Utilization of Fiber Obtained from Barley Malt Pulp as a Fat Substitute in the Production of Low Fat Mayonnaise

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    Introduction Introduction: Mayonnaise is one types of sauces that has always been loved and preferred by consumers because of its unique texture and taste. Sauce is a semi-solid or liquid food ingredients that consists of emulsifying edible vegetable oils (at least 66%) in a liquid phase including vinegar, water, lemon juice, and egg yolk (Bortnowska and Makiewiewicz, 2006). According to the National Standard of Iran (No. 2454), if the amount of fat in mayonnaise is reduced by at least 25% (from 66% of fat), it is considered reduced fat mayonnaise, and if it is reduced by 50% in fat, mayonnaise is considered low-fat. (National Standard of Iran 2454, 1394). Fibers are edible parts of plants or similar carbohydrates that cannot be absorbed in the gut and only irritate the gut. Dietary fiber contains polysaccharides, oligosaccharides, lignin and related plant materials. Dietary fiber intake can reduce the risk of cardiovascular disease, high blood pressure, diabetes, obesity, cancer and some gastrointestinal disorders. They can alter tissue properties, eliminate hydration, stabilize high-fat foods and emulsions, and improve shelf life (Zhang et al., 2017). Barley (Avena sativa L.) is an important crop with about 21 million tons annually production worldwide. The seed has been used to raise public awareness about the health benefits of beta-glucan, which helps lower blood cholesterol and glucose levels. Protein is the second most abundant element (12 to 20%) in barley after starch, which contains organic amino acids, due to its high lysine content because globulins make up 70 to 80% of total barley protein. Alcohol-soluble prolamins, on the other hand, are the main storage proteins in other cereals (Nito et al., 2015).   Materials and Methods  In this study, nitrate, ethanol, methanol, chloroform, ethylene glycol and acetic acid were prepared from Merck Company (Germany) and sunflower oil from Rana Company, vinegar from Somayeh Company, salt from Aali Company, sugar from Pardis Company, mustard from Bijan Company and Barley Malt Pulp was prepared from Behnoosh Company. Chemical extraction method was used to extract fiber. (Salehifar and Fadai Noghani, 2013). To prepare the mayonnaise samples, the powder ingredients including salt, mustard and sugar, vinegar and water were first mixed well and uniformly with a mixer (IKA WERK, Germany). Then, according to the formulation, the fiber extracted from barley malt pulp was gradually added to the above mixture, which was stirring, and the eggs were added to the mixture and mixed thoroughly to obtain a uniform composition. At this stage, the oil was added dropwise with continuous pouring. Finally, the samples of mayonnaise prepared were kept at refrigerator for further analysis. In all samples, the amount of sugar (11.5 g), white vinegar (23.1 g), eggs (39.45 g), salt (4.50 g), water (24.6 g) was constant (Bostani et al., 2011). In this study, in order to reduce the amount of oil, it was replaced with fiber extracted from barley malt pulp at five levels of 0, 5, 10, 15 and 20% (w / w).     Results and Discussion  The effect of replacing different percentages of fibers extracted from barley malt pulp with fat at levels (5, 10, 15 and 20%) on physicochemical properties (fat, fiber, ash, viscosity and colorimetry (L*) a*, b*) and sensory characteristics (taste, smell, color, texture and general acceptance) were determined using analysis of variance at 5% probability level. Various properties of low-fat mayonnaise showed that as the percentage of barley malt fiber increased, the amount of fat, radiance and yellowness in low-fat mayonnaise treatments (P 0.05) as well as protein content. In the treatments, which was statistically significant (P> 0.05), the results of sensory evaluation of mayonnaise samples showed that the addition of fiber extracted from barley malt pulp resulted in a significant reduction in taste, texture, color and the general acceptance of mayonnaise samples (P 0.05), so that the treatment containing 20% barley malt fiber had the lowest sensory score (taste). Smell, texture, color, acceptance k Li) and treatments containing 5 and 10% barley malt fiber received the highest sensory scores (taste, odor, texture, color, general acceptance) from the panelists.   Conclusion  According to the results, treatment 3 (containing 10% barley malt fiber) was introduced as the best treatment in the present study

    Design and evaluation of the performance of local exhaust hood on the welding torch

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    Background and aims: Threats against welders' health due to exposure to welding fume is an important issue; thus, controlling and examining effective exhaust of fumes are necesary. In this study, was evaluated prototype operation of local exhaust ventilation on-gun in bench scale. Methods: Duct velocity average was determined using traverse points method and calculated flow rate by hood using ACGIH standard method. Also capture velocity close in contaminant source (Arc Point) was measured using thermal anemometer. Then, in order to determine total particles concentration and capture efficiency created by system NIOSH 7200 standard method was used. Results: Duct velocity average and created flow rate by evaluated system were 6296.1±92.50 fpm and 34.06±0/50 scfm, respectively. Also, capture velocity in close of the weld point was obtained 140 fpm. Sampling results for averaged total particles concentration in off and on positions of system were 75±7 mg/m3 and 16.7±4 mg/m3, respectively. As a result, 77 containment efficiency was achieved by this system. Conclusion: The local exhaust ventilation used in this study was a low cost prototype and according to the acheived results, it leads to reduce total particles concentration (T.P) in breathing zone aproximately to 22

    Enhanced performance of non-thermal plasma coupled with TiO2/GAC for decomposition of chlorinated organic compounds: Influence of a hydrogen-rich substance

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    Background: No study was found in the literature on the combination of TiO 2 /GAC catalyst and non-thermal plasma for chlorinated volatile organic compounds abatement in air. This paper presents this hybrid process for the decomposition of chloroform (as a target compound) using a multi-pin to plate discharge reactor. The experiments were performed using a high frequency pulsed transformer as the power supply system to examine the effect of SIE, frequency, as well as initial concentration on the chloroform removal efficiency (RE). Toluene was added as a hydrogen-rich source to shift the reactions into the formation of environmentally desirable products. Results: RE of around 60% was observed with the NTP-alone process at the highest possible SIE (3000 J L -1 ), while it rocketed up to 100% (total oxidation) in the presence of TiO 2 /GAC at SIE of 1000 J L -1 . About 100% O 3 destruction over TiO 2 /GAC and both adsorption and catalytic activities of GAC may be considered as the reasons for better performance of the hybrid process. Toluene feeding diminished the chlorinated by-products such as Cl 2 and TCE significantly. The selectivity towards CO 2 was noticed to enhance noticeably, when both catalyst and toluene were introduced, regardless of the input concentration. Conclusions: Our findings suggest that the hybrid of NTP with TiO 2 /GAC will highly be effective in the abatement of chloroform, and the addition of toluene will successfully decline harmful chlorinated by-products. © 2014 Abedi et al., licensee BioMed Central Ltd

    A new route to control texture of materials: Nanostructured ZnFe2O4 photoelectrodes

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    Studies were conducted to investigate the influence of deposition solution composition (methanol ≤ the deposition solvent ≤ ethanol) on their physical and chemical properties that matters in the aerosol formation and subsequent decomposition during the aerosol assisted chemical vapour deposition (AACVD) of ZnFe2O4 electrodes. The FEGSEM studies found that the change of composition of deposition solution produced a dramatic change in the ZnFe2O4 electrode texture. The ZnFe2O4 electrodes deposited from methanol as well as predominately methanolic solvents had a relatively compact morphology. In contrast, the electrodes deposited from ethanol as well as predominately ethanolic solvents showed highly textured rod-like structure at nanoscale. The change in electrode texture is explained in terms of changes occurred in precursor decomposition pathways from heterogeneous and homogeneous when the composition of deposition solution is systematically varied. The photoelectrochemical (PEC) properties of all ZnFe2O4 electrodes were studied by recording JeV characteristics under AM1.5 illumination and the photocurrent spectra. The textured electrodes exhibited a significantly higher photocurrent compared to their compact counterparts. This is attributed to the improved photogenerated minority carrier collection at the ZnFe2O4/electrolyte interface as the average feature size gradually decreased. The photocurrent density (at 0.25 V vs. Ag/AgCl/3M KCl) increases rapidly when the electrode is deposited from the solvent containing 60% ethanol and above, which is in close agreement with the textural changes taken place in ZnFe2O4 electrodes.Web of Scienc
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