4,607 research outputs found
Removal of benzotriazole by Photo-Fenton like process using nano zero-valent iron: Response surface methodology with a Box-Behnken design
In this paper, the removal of benzotriazole (BTA) was investigated by a Photo-Fenton process using nano zero valent iron (NZVI) and optimization by response surface methodology based on Box-Behnken method. Effect of operating parameters affecting removal efficiency such as H2O2, NZVI, and BTA concentrations as well as pH was studied. All the experiments were performed in the presence of ultraviolet radiation. Predicted levels and BTA removal were found to be in good agreement with the experimental levels (R2 = 0. 9500). The optimal parameters were determined at 60 min reaction time, 15 mg L-1 BTA, 0.10 g L-1 NZVI, and 1.5 mmol L-1 H2O2 for Photo-Fenton-like reaction. NZVI was characterized using X-ray diffraction (XRD), transmission electron microscope (TEM) images, and scanning electron microscope (SEM) analysis
Heterogeneous oxidation of sulfacetamide in aquatic environment using ultrasonic and nano-fenton: Kinetics intermediates and bioassay test
In present study, degradation of sulfacetamide from a synthetic wastewater by sonofenton process using zero valent iron nanoparticles was investigated. The synthesized iron nanoparticles were characterized using transmission electron microscopy (TEM), UV-visible and X-ray diffraction pattern (XRD). The effect of various parameters, such as pH, nZVI dose, H2 O2 concentration and contact time was studied with batch experiments. The removal efficiency of sulfacetamide by US/nZVI/H2 Of process was about 91 for reaction time of 60 min, but less than 27 of chemical oxygen demand (COD) was removed. Kinetics studies showed that the degradation of sulfacetamide fitted well to the pseudo-second-order model. Using the LC/MS device, five intermediate from degradation of sulfacetamide were detected. The toxicity test, using micro toxicity study also showed that the effluent from the sono-Fenton reactor has a lower toxicity than sulfacetamide antibacterial. © 2019 Desalination Publications. All rights reserved
Inactivation of Fecal coliforms during solar and photocatalytic disinfection by zinc oxide (ZnO) nanoparticles in compound parabolic concentrators (CPCs)
Water samples of 0, 50, and 100 nephelometric turbidity units (NTU) spiked with fecal coliforms (107 CFU/ml) were exposed to natural sunshine in 1l quartz glass tubes fitted with rectors' compound parabolic concentrators CPCS at two forms CPC1 (whit nanoparticle zinc oxide) and CPC2(without nanoparticle zinc oxide). The samples were characterized using the X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscope (TEM). On clear days, the complete inactivation times (more than 7-log unit reduction in bacterial population) in the systems with CPC1, and CPC2 were 15, and 30 min, respectively. The maximum temperatures obtained in the water samples were 80°C for CPC1, and 82°C for CPC2. The use of CPC1 with hydroxyl radicals (OH·) production significantly improved the efficiency of the old CPCS technique, since these systems (CPC1-2) shortened the exposure times to solar radiation and also minimized the negative effects of turbidity and also regrowth was zero in the disinfected samples. Due to two simultaneous effects of high temperatures and UV, regrowth in most ways of solar disinfection was not seen in these examples. Overall, this technology has been proved to be a good enhancement method to inactivate microorganisms under real conditions and represents a good alternative technique to drinking water treatment. © 2019, Islamic Azad University
MAGNETIC AND ELECTRIC FIELD EFFECTS ON THE BINDING ENERGY OF A SHALLOW DONOR IN QUANTUM DOT–QUANTUM WELL
We studied the simultaneous of the magnetic and electric field effects on the binding energy for a shallow donor confined to move in spherical Quantum Dot – Quantum Well (GaAs-GaAlAs). Calculations are performed in the framework of the effective mass approximation using the Hass variational approach. We describe the effect of the quantum confinement by a infinite deep potential. The result shows that the corrections due to the magnetic and electric field are very important and cannot be neglected or ignored. We have demonstrated the existence of a critical value (a/b)cri which can be used to distinguish the three dimensions confinement from the spherical surface confinement and it’s may be important for the nanofabrication techniques.We studied the simultaneous of the magnetic and electric field effects on the binding energy for a shallow donor confined to move in spherical Quantum Dot – Quantum Well (GaAs-GaAlAs). Calculations are performed in the framework of the effective mass approximation using the Hass variational approach. We describe the effect of the quantum confinement by a infinite deep potential. The result shows that the corrections due to the magnetic and electric field are very important and cannot be neglected or ignored. We have demonstrated the existence of a critical value (a/b)cri which can be used to distinguish the three dimensions confinement from the spherical surface confinement and it’s may be important for the nanofabrication techniques
The effect of 12 weeks regular physical activity and vitamin E in the treatment of non-alcoholic steatohepatitis: A pilot study
Background: Despite the prevalence of Non-Alcoholic Fatty Liver Disease (NAFLD) and Non-Alcoholic Steatohepatitis (NASH), there was no treatment has been proven to be effective in these common diseases. Although many studies have shown that lifestyle modifications such as increasing physical activities and exercise could be effective in the treatment of these common diseases, the optimal strategy was still not determined. According to the beneficial effects of antioxidant agents in the treatment of NASH, vitamin E has been used for this purpose by some clinicians. We designed this study for assessing beneficial effects of regular physical activity on the biochemical and imaging responses in patients with NASH and comparing this with vitamin E as an accepted treatment for NASH. Materials and Methods: This study was Randomized and single-blind clinical trials were carried out in Gonbad-e Kavus through which a total of 30 consecutive patients with the ultra sonographic diagnosis of non-alcoholic steatohepatitis (NASH)were enrolled and randomized to one of the three groups: Vitamin E 800 mg/day, regular physical activity, or both. Results: In all treatment groups improvement in liver transaminases level, serum lipids and ultrasonographic grading of fatty liver occurred after three months of treatment. When these decrement was compared between the treatment groups, there was no statistically significant difference in the value of improvement between the three groups (ANOVA: p>0.5). I.e. all three interventions improved the biochemical and ultrasonographic finding of fatty liver in the same way. Both groups with regular exercise had significant mean weight loss in comparison with the vitamin E group (a mean decrease of 3.0 kg in exercise group, 5.8 kg in subjects on regular exercise plus vitamin E and 0.2 kg in vitamin E group, ANOVA: p=0.04). Conclusion: There were no significant differences between exercise and vitamin E alone or in combination regarding the reduction in the level of liver enzymes and sonographic evidences of fatty liver although both resulted in significant improvements in biochemical endpoints. This implies that physical activity could be considered as effective as vitamin E in the improvement of biochemical and ultrasonographic presentations of NASH and the addition of Vitamin E does not offer any benefits. According to the findings of this pilot study a full-powered study with a control group should be designed. © 2015, Iranian Association of Gastroenterology and Hepatology. All rights reserved
The effect of 12 weeks regular physical activity and vitamin E in the treatment of non-alcoholic steatohepatitis: A pilot study
Background: Despite the prevalence of Non-Alcoholic Fatty Liver Disease (NAFLD) and Non-Alcoholic Steatohepatitis (NASH), there was no treatment has been proven to be effective in these common diseases. Although many studies have shown that lifestyle modifications such as increasing physical activities and exercise could be effective in the treatment of these common diseases, the optimal strategy was still not determined. According to the beneficial effects of antioxidant agents in the treatment of NASH, vitamin E has been used for this purpose by some clinicians. We designed this study for assessing beneficial effects of regular physical activity on the biochemical and imaging responses in patients with NASH and comparing this with vitamin E as an accepted treatment for NASH. Materials and Methods: This study was Randomized and single-blind clinical trials were carried out in Gonbad-e Kavus through which a total of 30 consecutive patients with the ultra sonographic diagnosis of non-alcoholic steatohepatitis (NASH)were enrolled and randomized to one of the three groups: Vitamin E 800 mg/day, regular physical activity, or both. Results: In all treatment groups improvement in liver transaminases level, serum lipids and ultrasonographic grading of fatty liver occurred after three months of treatment. When these decrement was compared between the treatment groups, there was no statistically significant difference in the value of improvement between the three groups (ANOVA: p>0.5). I.e. all three interventions improved the biochemical and ultrasonographic finding of fatty liver in the same way. Both groups with regular exercise had significant mean weight loss in comparison with the vitamin E group (a mean decrease of 3.0 kg in exercise group, 5.8 kg in subjects on regular exercise plus vitamin E and 0.2 kg in vitamin E group, ANOVA: p=0.04). Conclusion: There were no significant differences between exercise and vitamin E alone or in combination regarding the reduction in the level of liver enzymes and sonographic evidences of fatty liver although both resulted in significant improvements in biochemical endpoints. This implies that physical activity could be considered as effective as vitamin E in the improvement of biochemical and ultrasonographic presentations of NASH and the addition of Vitamin E does not offer any benefits. According to the findings of this pilot study a full-powered study with a control group should be designed. © 2015, Iranian Association of Gastroenterology and Hepatology. All rights reserved
Ark or park: the need to predict relative effectiveness of ex situ and in situ conservation before attempting captive breeding
1. When species face extinction, captive breeding may be appropriate. However, captive breeding may be unsuccessful, while reducing motivation and resources for in situ conservation and impacting wild source populations. Despite such risks, decisions are generally taken without rigorous evaluation. We develop an individual-based, stochastic population model to evaluate the potential effectiveness of captive-breeding and release programmes, illustrated by the Critically Endangered Ardeotis nigriceps Vigors great Indian bustard. 2. The model was parameterized from a comprehensive review of captive breeding and wild demography of large bustards. To handle uncertainty in the standards of captive-breeding performance that may be achieved we explored four scenarios of programme quality: ‘full-range’ (parameters sampled across the observed range), ‘below-average’, ‘above-average’ and ‘best possible’ (performance observed in exemplary breeding programmes). Results are evaluated examining i) the probability of captive population extirpation within 50 years and ii) numbers of adult females subsequently established in the wild following release, compared to an alternative strategy of in situ conservation without attempting captive breeding. 3. Successful implementation of captive breeding, involving permanent retention of 20 breeding females and release of surplus juveniles, required collection of many wild eggs and consistent ‘best possible’ performance across all aspects of the programme. Under ‘full-range’ and ‘above-average’ scenarios captive population extirpation probabilities were 73–88% % and 23‒51%% respectively, depending on egg collection rates. 4. Although most (73‒92%) ‘best possible’ programmes supported releases, re-establishment of free-living adults also required effective in situ conservation. Incremental implementation of effective conservation measures over the initial 10 years resulted in more free-living adults within 35 years if eggs were left in the wild without attempting captive breeding. 5. Synthesis and applications. For the great Indian bustard Ardeotis nigriceps, rapid implementation of in situ conservation offers a better chance to avoid extinction than captive breeding. Demographic modelling should be used to examine whether captive breeding is likely to bring net benefits to conservation programmes
Discrete dipole approximation for time-domain computation of optical forces on magnetodielectric scatterers
We present a general approach, based on the discrete dipole approximation (DDA), for the computation of the exchange of momentum between light and a magnetodielectric, three-dimensional object with arbitrary geometry and linear permittivity and permeability tensors in time domain. The method can handle objects with an arbitrary shape, including objects with dispersive dielectric and/or magnetic material responses. © 2011 Optical Society of America
Coupled-dipole method in time domain
We present a time-domain formulation of electrodynamics based on the self-consistent derivation of the electromagnetic field in a linear, dispersive, lossy object via the coupled dipole method. © 2008 Optical Society of America
Dual Faces Architecture of Nias
Many Indonesian people built a traditional house based on beliefs of their ancestors for generations, without knowing the scientific reason. Meanwhile, indirectly, ancestors already thinking about housing that adapts the environmental conditions such as in Nias Island. Nias is an island that has two different forms of traditional houses which are affected by the differences geographic, highland and lowland. Geographic factors and beliefs not only affect the shape of the house but also the structure of the house. Located on the earthquake fault lines, Nias traditional houses was designed to withstand earthquakes that often befall. A study using description and analysis methods about design and structure which used in traditional houses in Nias Island, would develop a good sense of the idea to apply these materials on modern building to preserve the culture of Indonesia
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