854 research outputs found
The Effect of Different Fuels on Particle Size and Morphology of FTO Nano Powder Synth-sized by Gel Combustion Method
In this study, a gel combustion method was used to prepare fluorine-doped tin oxide (FTO) nano
powders. Stannous chloride dehydrate, hydrofluoric acid, and different fuels of glycine, urea, and citric
acid were used to synthesize FTO nano powder, followed by calcination at 600 °C. The results showed
that using citric acid as a fuel gives homogenous FTO nano powder with average particle size of 40 nm
and round morphology.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3489
The Effect of Raw Materials Molar Ratio in Mechanochemical Synthesis of Amorphous Fe-B Alloy Nanoparticles
In this study, amorphous iron-boron alloy nanoparticles successfully synthesized by mechanochemical
method. The raw materials were ferrous sulfate heptahydrate (FeSO4.7H2O) as a source of iron and sodium
borohydride (NaBH4) as a reducing agent. Powders grinding was performed with different
NaBH4/FeSO4.7H2O molar ratio. The results revealed that high active and completely amorphous particles
could be synthesized with the molar ratio of 4:1 for NaBH4:FeSO4 in 10 minutes of grinding time. Various
characterizations, such as the chemical analysis, atomic absorption spectroscopy (AAS), fourier transform
infrared spectroscopy (FT-IR), x-ray diffraction (XRD) and field emission scanning electron microscopy
(FESEM) have been performed. The XRD results confirmed the formation of the amorphous phase. Other
results also indicate the formation of amorphous alloy nanoparticles with an average particle size below 50
nm and the composition was Fe-10 Wt
percent B.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3489
Design and Experimental Validation of a Ducted Counter-rotating Axial-flow Fans System
An experimental study on the design of counter-rotating axial-flow fans was
carried out. The fans were designed using an inverse method. In particular, the
system is designed to have a pure axial discharge flow. The counter-rotating
fans operate in a ducted-flow configuration and the overall performances are
measured in a normalized test bench. The rotation rate of each fan is
independently controlled. The relative axial spacing between fans can vary from
17% to 310%. The results show that the efficiency is strongly increased
compared to a conventional rotor or to a rotor-stator stage. The effects of
varying the rotation rates ratio on the overall performances are studied and
show that the system has a very flexible use, with a large patch of high
efficient operating points in the parameter space. The increase of axial
spacing causes only a small decrease of the efficiencyComment: accepted in Journal of Fluid Engineerin
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Distinctive Mechanisms and Patterns of Exudative Versus Tractional Intraretinal Cystoid Spaces as Seen With Multimodal Imaging.
PurposeTo determine clear-cut distinctions between tractional and exudative intraretinal cystoid spaces subtypes.DesignRetrospective, multicenter, observational case series.MethodsA cohort of patients diagnosed with intraretinal cystoid spaces and imaged with optical coherence tomography (OCT), fluorescein angiography (FA), blue fundus autofluorescence (BFAF), en face OCT, and OCT angiography (OCT-A) was included in the study. All images were qualitatively and quantitatively evaluated.ResultsIn this study were included 72 eyes of 69 patients. Exudative intraretinal cystoid spaces (36/72 eyes, 50%) displayed a "petaloid" morphology as seen with en face OCT, FA, and BFAF. Tractional intraretinal cystoid spaces (24/72 eyes, 33.3%), displayed a radial "spoke-wheel" en face OCT pattern. There was no leakage with FA and BFAF did not reveal specific patterns. Eyes with full-thickness macular hole (FTMH, 12/72 eyes, 16.7%) displayed a "sunflower" en face OCT appearance. FTMH showed OCT, OCT-A, and BFAF features of both exudative and tractional cystoid spaces, but without any FA leakage. Inner nuclear layer (INL) thickness was significantly lower in tractional cystoid spaces (P < .001). There were a greater number of INL cystoid spaces in both the exudative and FTMH subgroups (P = .001). The surface area of INL cystoid spaces was significantly lower in the tractional subgroup (P < .001). There was a significant reduction of the microvascular density in eyes with exudative vs tractional (P = .002) and FTMH (P < .001) subgroups.ConclusionsExudative and tractional intraretinal cystoid spaces displayed characteristic multimodal imaging features and they may represent 2 different pathologic conditions with equally different clinical implications
Synthesis of Single-Phase Anatase TiO2 Nanoparticles by Hydrothermal Treatment
Pure anatase powders of titanium dioxide with a homogeneous nanosized particles distribution were
prepared by a facile hydrothermal route using solution of acetic acid and tetraisopropyl orthotitanate as
the precursors with a molar ratio of 1:1. The modified hydrolyzed alkoxide was treated at various temperatures under different autogenic pressures. Two different reactors were employed as autoclaves for heating
and generation of high pressures during the synthesis and crystallization of TiO2 nanoparticles. The characteristics of TiO2 powders obtained under various synthesis conditions were verified using X-Ray Diffraction (XRD) and Field Emission Scanning Electron Microscopy (FE-SEM). The results indicated that particles size of the formed TiO2 could be finely tuned by varying the experimental parameters of temperature,
pressure and the amount of nitric acid in the peptization step. TiO2 nanoparticles with good dispersion and
mean size of about 9 nm could be seen in FE-SEM image of sample synthesized under temperature of 160
°C for 12 h using more nitric acid in the peptization step.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3488
Alterations in the Choriocapillaris in Intermediate Age-Related Macular Degeneration.
Purpose The purpose of this study was to compare the choriocapillaris plexus in eyes with intermediate AMD (iAMD), with or without neovascular AMD in the fellow eye, using optical coherence tomography angiography (OCTA). Methods We collected data from 42 eyes with iAMD from 42 patients who had obtained OCTA. This cohort was divided into two subgroups according to the status of the fellow eye, yielding a group of 20 cases with bilateral intermediate AMD (bilateral iAMD group) and 22 cases with neovascular AMD in the fellow eye (unilateral iAMD group). An additional control group of 20 eyes from 20 healthy subjects was included for comparison. Main outcome measures were: (1) the percent of nondetectable perfused choriocapillaris area and (2) the average choriocapillaris signal void size. Results No differences in the percent of nondetectable perfused choriocapillaris area were found among the three groups (2.3 ± 1.4% in the unilateral iAMD group, 1.5 ± 0.9% in the bilateral iAMD group, and 1.7 ± 1.4% in the control group, respectively). The average choriocapillaris signal void size, however, was significantly increased in unilateral iAMD eyes (293.7 ± 71.2 μm2) compared to both bilateral iAMD (241.5 ± 51.6 μm2, P = 0.031) and control (212.7 ± 48.6 μm2, P = 0.001) eyes. Conclusions Intermediate AMD eyes of patients with neovascular AMD in the fellow eye have an increased average choriocapillaris signal void size compared to eyes without neovascular AMD in the fellow eye. If replicated in future studies, choriocapillaris signal void size may prove to be a useful parameter for evaluating eyes with AMD
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Selection of lubricant material for the roller chains of the AHM grapple drive system for the CRBRP
Properties of Anderol 732 lubricating grease are evaluated to meet the design requirements for the Clinch River Breeder Reactor Plant (CRBRP) auxiliary machine (AHM) chain lubrication. Based on the evaluation made in this report, the material is recommended as a lubricant for the specified application. The material is to be applied by the chain manufacturer prior to installation in the AHM
Prescription pattern in ischemic heart disease inpatients at B. P. Koirala Institute of Health Sciences: a cross sectional study
Background: Drug utilization pattern studies seek to screen, evaluate and suggest appropriate modifications in prescription practices. It would help to make patient care rational and cost effective. Objective was to analyze the drug prescribing pattern for treatment of ischemic heart disease (IHD).
Methods: A prospective cross-sectional observational study was conducted in patients of IHD admitted in intensive coronary care unit and medicine ward for the period of six months. Data were collected in preformed case record form. The data were analyzed for drug use indicators, demographic parameters, morbidities, pattern of drug use using Microsoft excel 2010.
Results: A total of 145 patients were enrolled out of that 89 (61.38%) were males. The mean age was 60.01±12.71 years and majority (26.89%) belonged to age group of 61-70 years. A total of 1208 drugs were prescribed in 145 patients. Most frequently prescribed drugs were antiplatelet group of drugs 100% encounters, followed by hypo-lipidemics (98.62%). Average number of drugs per encounter was 8.33 and percentage of drugs prescribed by generic name was 5.04%.
Conclusions: IHD was more common in males than females. The most commonly prescribed drug classes were anti-platelet drugs followed by hypolipidemic agents
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