673 research outputs found

    The Effect of Different Fuels on Particle Size and Morphology of FTO Nano Powder Synth-sized by Gel Combustion Method

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    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

    Design and Experimental Validation of a Ducted Counter-rotating Axial-flow Fans System

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    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

    Influence of Anchorage on the Behavior of CFRP RC Beams in Flexure

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    This research study involves experimental and theoretical investigations of thebehavior of flexural debonding of carbon fiber reinforced polymer (CFRP) laminateswith steel anchorages. A total of nine reinforced concrete beam specimens with crosssection of (150mm width by 250mm height and 2000mm length) were investigated inthis study to observe the flexural strength of each one. Eight beam specimens werestrengthened with CFRP laminates and one beam specimen was tested withoutstrengthening. The experimental results showed that the use of CFRP strips as externalstrengthening has significant positive effect on ultimate loads, crack patterns anddeflections. The percent of increasing of the ultimate load capacity can be increased byabout 65% when using two layers of CFRP strips instead of one layer. The ultimateload is increased by about 118% for the beams strengthened with bonded CFRP andexternal anchorage with respect to the reference beam. Three-dimensional nonlinearfinite element analysis (i.e. ANSYS - version 9.0 computer program ) is used toinvestigate the performance of reinforced concrete beams strengthened with CFRP.The comparison between the numerical and the experimental results asserted that goodvalidity of the numerical analysis and the methodology developed in this study

    Design and Experimental Validation of a Ducted Counter-Rotating Axial-Flow Fans System

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    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 efficiency

    Behavior of Short Span Composite Beams Strengthened with CFRP Strips

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    The experimental program in this paper is divided into two groups: the firstone consists of seven composite beams; six of them were strengthened with oneand two CFRP strips and with three different percentages of full beam length(40%, 60%, and 100%). The second group consists of five composite beamsstrengthened at the face of the bottom flange with CFRP strips fastened to the steelsection by steel bolts with two different length proportion of CFRP strips to beamsoffit (60%, and 100%).The analytical investigation included the use of three dimensionalnonlinear finite elements to model the performance of the composite beams using(ANSYS 8.0) computer program

    Relationship between nerve fiber layer hemorrhages and outcomes in central retinal vein occlusion

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    Copyright 2020 The Authors PURPOSE. To evaluate the depth and pattern of retinal hemorrhage in acute central retinal vein occlusion (CRVO) and to correlate these with visual and anatomic outcomes. METHODS. Retinal hemorrhages were evaluated with color fundus photography and fluorescein angiography at baseline and follow-up. Snellen visual acuity (VA), central foveal thickness (CFT), extent of retinal ischemia, and development of neovascularization were analyzed. RESULTS. 108 eyes from 108 patients were evaluated. Mean age was 63.6 ± 16.1 years with a predilection for the right eye (73.1%). Average follow-up was 17.2 ± 19.2 months. Mean VA at baseline was 20/126 and 20/80 at final follow-up. Baseline (P = 0.005) and final VA (P = 0.02) in eyes with perivascular nerve fiber layer (NFL) hemorrhages were significantly worse than in eyes with deep hemorrhages alone. Baseline CFT was greater in the group with perivascular hemorrhages (826 ± 394 μm) compared to the group with deep hemorrhages alone (455 ± 273 μm, P \u3c 0.001). The 10 disc areas of retinal ischemia was more common in patients with perivascular (80.0%) and peripapillary (31.3%) versus deep hemorrhages alone (16.1%, P \u3c 0.001). Neovascularization of the iris was more common, although this differrence was not significant, in the groups with peripapillary (14.3%) and perivascular (2.0%) NFL versus deep hemorrhages alone (0.0%). CONCLUSIONS. NFL retinal hemorrhages at baseline correlate with more severe forms of CRVO, with greater macular edema, poorer visual outcomes, and greater risk of ischemia and neovascularization. This may be related to the organization of the retinal capillary plexus. The depth and pattern of distribution of retinal hemorrhages in CRVO may provide an easily identifiable early biomarker of CRVO prognosis

    Novel KRIT1/CCM1 mutation in a patient with retinal cavernous hemangioma and cerebral cavernous malformation

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    Retinal cavernous hemangiomas are rare vascular anomalies, and can be associated with cerebral cavernous malformations (CCM). Distinct mutations have been reported in patients who have both CCMs and retinal cavernous hemangiomas. Fluorescein angiography, spectral domain optical coherence tomography, and genetic testing were performed on a patient with a retinal cavernous hemangioma and a CCM. Our patient was heterozygous in the KRIT1/CCM1 gene for a frameshift mutation, c.1088delC. This would be predicted to result in premature protein termination. We have identified a novel mutation in the KRIT1/CCM1 gene in a patient with both CCM and retinal cavernous hemangioma. We hypothesize that the occurrence of retinal cavernous hemangiomas and CCMs is underlaid by a common mechanism present in the KRIT1/CCM1 gene

    Consensus Nomenclature for Reporting Neovascular Age-Related Macular Degeneration Data: Consensus on Neovascular Age-Related Macular Degeneration Nomenclature Study Group

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    © 2019 American Academy of Ophthalmology Purpose: To establish a process to evaluate and standardize a state-of-the-art nomenclature for reporting neovascular age-related macular degeneration (AMD) data. Design: Consensus meeting. Participants: An international panel of retina specialists, imaging and image reading center experts, and ocular pathologists. Methods: During several meetings organized under the auspices of the Macula Society, an international study group discussed and codified a set nomenclature framework for classifying the subtypes of neovascular AMD and associated lesion components. Main Outcome Measures: A consensus classification of neovascular AMD. Results: The study group created a standardized working definition of AMD. The components of neovascular AMD were defined and subclassified. Disease consequences of macular neovascularization were delineated. Conclusions: The framework of a consensus nomenclature system, a definition of AMD, and a delineation of the subtypes of neovascular AMD were developed. Establishing a uniform set of definitions will facilitate comparison of diverse patient groups and different studies. The framework presented is modified and updated readily, processes that are anticipated to occur on a periodic basis. The study group suggests that the consensus standards outlined in this article be used in future reported studies of neovascular AMD and clinical practice

    Urbanisation and sexual health: Understanding bisexually active men in Hanoi, Vietnam

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    Background: Men who have sex with men (MSM) in Vietnam are receiving increased attention in recognition of their high-risk behaviours and potential for human immunodeficiency virus(HIV) infection and transmission. Due to societal pressures, many MSM in Vietnam are also bisexually active, which ultimately increases the transmission risks beyond the MSM population. Evidence is emerging that indicates a greater proportion of women in Asia with low-risk sexual activities are contracting HIV from their male partners who have become HIV infected through male–male sex. Methodology: Fourteen focus group discussions exploring sexual and social networks were conducted in Hanoi between July 2010 and September 2010. A total of 96 individuals participated in these sessions. Findings: A risk environment approach was used to analyse the focus group themes of social stigma and marriage, sex with other men in closed settings and transactional sex in Hanoi, an increasingly urbanising and westernising city. Implications: Despite limited evidence globally that bisexual men act as a bridge for sexually transmitted diseases, there is particular concern in Vietnam about this potential risk. HIV rates amongst MSM are rapidly rising and there are reports of women contracting HIV from their male partners who are bisexually active
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