11 research outputs found

    Comparative analysis of the results of theoretical and experimental studies of freight wagon Sdggmrss-twin

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    This paper presents a comparative analysis based on the results from static strength calculation of wagon body, series Sdggmrss-twin, and on the results from the real wagon test. The verification of results from calculations and tests and their comparison was mandatory for client's commissioning of the wagon by notified body. Calculations based on the finite elements method were carried out in the Department of Railway Engineering at Technical University of Sofia. Experimental studies on real wagon construction were conducted at the facilities of Bulgarian National Transport Research Institute by testing team from Laboratory of rail vehicles at University of Belgrade. It was found that the obtained static stress results are similar, which proves that the proposed models are appropriate and they can help to solve a wide range of issues, for example those related to lightweight design of railway vehicles

    Comparative analysis of the results of theoretical and experimental studies of freight wagon Sdggmrss-twin

    Get PDF
    This paper presents a comparative analysis based on the results from static strength calculation of wagon body, series Sdggmrss-twin, and on the results from the real wagon test. The verification of results from calculations and tests and their comparison was mandatory for client's commissioning of the wagon by notified body. Calculations based on the finite elements method were carried out in the Department of Railway Engineering at Technical University of Sofia. Experimental studies on real wagon construction were conducted at the facilities of Bulgarian National Transport Research Institute by testing team from Laboratory of rail vehicles at University of Belgrade. It was found that the obtained static stress results are similar, which proves that the proposed models are appropriate and they can help to solve a wide range of issues, for example those related to lightweight design of railway vehicles

    Sem/Edx and Xrd Characterization of Silver Nanocrystalline Thin Film Prepared from Organometallic Solution Precursor

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    The Ag nano-structured thin films prepared on flat glass substrates have been studied. The ball-like silver nanoparticles have been synthesized in large quantity by using a modified method of hydrolytic decomposition of silver complexes with amino types ligands formed in ethanol aqueous solution. SEM analysis revealed that Ag nanoparticles are all sphere shaped with bimodal size (40 and 70 nm) distribution. The results of XRD powder pattern examination show that Ag nanoparticles are pure phase, well crystallized. The unit cell dimensions measured on synthesized Ag nano films show small but frequent contraction in comparison to Ag metal standard

    Hepatoprotective Effect of Mixture of Dipropyl Polysulfides in Concanavalin A-Induced Hepatitis

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    The main biologically active components of plants belonging to the genus Allium, responsible for their biological activities, including anti-inflammatory, antioxidant and immunomodulatory, are organosulfur compounds. The aim of this study was to synthetize the mixture of dipropyl polysulfides (DPPS) and to test their biological activity in acute hepatitis. C57BL/6 mice were administered orally with DPPS 6 h before intravenous injection of Concanavalin A (ConA). Liver inflammation, necrosis and hepatocytes apoptosis were determined by histological analyses. Cytokines in liver tissue were determined by ELISA, expression of adhesive molecules and enzymes by RT PCR, while liver mononuclear cells were analyzed by flow cytometry. DPPS pretreatment significantly attenuated liver inflammation and injury, as evidenced by biochemical and histopathological observations. In DPPS-pretreated mice, messenger RNA levels of adhesion molecules and NADPH oxidase complex were significantly reduced, while the expression of SOD enzymes was enhanced. DPPS pretreatment decreased protein level of inflammatory cytokines and increased percentage of T regulatory cells in the livers of ConA mice. DPPS showed hepatoprotective effects in ConA-induced hepatitis, characterized by attenuation of inflammation and affection of Th17/Treg balance in favor of T regulatory cells and implicating potential therapeutic usage of DPPS mixture in inflammatory liver diseases

    Modernization of the drainage system and ash slurry handling system in TPP Kostolac A

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    The paper describes the modernization of ash slurry drainage and handling from Units A1 and A2 devices for receiving, extinguishing and transporting bottom ash and fly ash from the boiler grate to silos and mass/volume process water sumps, with new technical solutions and experiences in exploitation. The main goal of the drainage system modernization and ash slurry handling system in TPP Kostolac A is to improve the system operation and to reduce the number of deadlocks during operation

    Acid and Temperature Treatments Result in Increased Germination of Seeds of Three Fescue Species

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    Efficient germination of fescue seeds is essential for successful establishment of meadows and pastures. This research was conducted to ascertain the effects of various acid and temperature treatments on seed germination in three fescue species: Festuca rubra, F (mina, and E pratensis. Seeds from different cultivars, populations, or lots were exposed either to four concentrations of sulfuric acid at three different time intervals (12 treatments) or six different temperatures at three different time intervals (18 treatments). Despite all belonging to the genus Festuca, the seed from different species responded differently to the treatments. The three optimum treatments for E rubra seed involved soaking in a 75% solution of sulfuric acid for 20 minutes (improved the germination rate by 19%), soaking in a 50% solution of sulfuric acid for 30 minutes (improved the germination rate by 18%) and exposure to either 60 degrees C or 70 degrees C for 90 minutes (improved the germination rate by 17%). For F. ovina seed, optimal treatments included soaking seeds for either 10 or 20 minutes in a 50% sulfuric acid solution (both treatments improved germination rates by 13%) or exposing seeds for 30 minutes in a 25% sulfuric acid solution and 80 degrees C for 60 minutes (improved germination rate by 12%). Two optimal treatments were identified for F. pratensis seed. Whereas the first involved soaking the seeds in a 75% sulfuric acid solution for 30 minutes (improved germination rates by 22%), the second involved either exposing the seeds to 90 degrees C for 90 or 60 minutes, or exposing the seeds to 80 degrees C for 90 minutes (improved germination rate by 21%). Our findings indicate that if fescue seed is to be sown during the autumn (two to three months after seed collecting), treating it with acid and temperature can significantly enhance its germination

    Hyponatraemia and changes in natraemia during hospitalization for acute heart failure and associations with in-hospital and long-term outcomes - from the ESC HFA EORP Heart Failure Long-Term Registry

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    Aims: To comprehensively assess hyponatraemia in acute heart failure (AHF) regarding prevalence, associations, hospital course, and post-discharge outcomes. Methods and results: Of 8,298 patients in the ESC-HF Long-Term Registry hospitalized for AHF with any ejection fraction, 20% presented with hyponatraemia (serum sodium <135ā€‰mmol/L). Independent predictors included lower systolic blood pressure, estimated glomerular filtration rate (eGFR) and haemoglobin, along with diabetes, hepatic disease, use of thiazide diuretics, mineralocorticoid receptor antagonists, digoxin, higher doses of loop diuretics, and non-use of angiotensin-converting-enzyme inhibitors/angiotensin receptor blockers and beta-blockers. In-hospital death occurred in 3.3%. The prevalence of hyponatraemia and in-hospital mortality with different combinations were: 9% hyponatraemia both at admission and discharge (hyponatraemia Yes/Yes, in-hospital mortality 6.9%), 11% Yes/No (in-hospital mortality 4.9%), 8% No/Yes (in-hospital mortality 4.7%), and 72% No/No (in-hospital mortality 2.4%). Correction of hyponatraemia was associated with improvement in eGFR. In-hospital development of hyponatraemia was associated with greater diuretic use and worsening eGFR but also more effective decongestion. Among hospital survivors, 12-month mortality was 19% and adjusted hazard ratios were for hyponatraemia Yes/Yes 1.60 (1.35-1.89), Yes/No 1.35 (1.14-1.59), and No/Yes 1.18 (0.96-1.45). For death or HF hospitalization they were 1.38 (1.21-1.58), 1.17 (1.02-1.33), and 1.09 (0.93-1.27), respectively. Conclusion: Among patients with AHF, 20% had hyponatraemia at admission, which was associated with more advanced HF and normalized in half of patients during hospitalization. Admission hyponatraemia (possibly dilutional), especially if it did not resolve, was associated with worse in-hospital and post-discharge outcomes. Hyponatraemia developing during hospitalization (possibly depletional) was associated with lower risk. This article is protected by copyright. All rights reserved
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