Repair of a damaged turbocharger

The turbocharger is among the highest quality assemblies for modern internal combustion engines. Its contribution to engine operation is immeasurable – it increases the power output of the engine while indirectly reducing fuel consumption. Like all devices, turbochargers require quality maintenance as they are susceptible to failure. Faulty turbochargers are either repaired or replaced with new ones. Repair ensures substantial financial savings. The paper presents the consequences of damage to the turbocharger and the process of its repair

Repair of a damaged turbocharger

The turbocharger is among the highest quality assemblies for modern internal combustion engines. Its contribution to engine operation is immeasurable – it increases the power output of the engine while indirectly reducing fuel consumption. Like all devices, turbochargers require quality maintenance as they are susceptible to failure. Faulty turbochargers are either repaired or replaced with new ones. Repair ensures substantial financial savings. The paper presents the consequences of damage to the turbocharger and the process of its repair

Biomechanical Modeling of Knee for Specific Patients with Chronic Anterior Cruciate Ligament Injury

In this study we modeled a patient specific 3D knee after anterior cruicate ligament (ACL) reconstruction. The purpose of the ACL reconstruction is to achieve stability in the entire range of motion of the knee and the establishment of the normal gait pattern. We present a new reconstruction technique that generates patient-specific 3D knee models from patient's magnetic resonant images (MRIs). The motion of the ACL reconstruction patients is measured by OptiTrack system with six infrared cameras. Finite element model of bones, cartilage and meniscus is used for determination stress and strain distribution at different body postures during gait analysis. It was observed that the maximum effective von Mises stress distribution up to 8 MPa occurred during 30% of the gait cycle on the meniscus. The biomechanical model of the knee joint during gait analysis can provide insight into the underlying mechanisms of knee function after ACL reconstruction

Cherry-the source of potential functional food

Serbia is among the top world producers of high-quality cherry fruit. Beside it refreshing taste cherries are rich source of many natural active principles. The most interesting among them are those one which exhibit antioxidant properties. It is possible to produce many derived products from cherries and one certainly is fruit wine. Such wine, is rich source of those natural active principles present in cherry fruit and the aim of this study is to investigate antioxidant properties of cherry wine. Fruit wines were produced from Serbian autochthonous sort of cherry. Microvinification was conducted with pure selected yeast culture and enzymatic preparation glycosidase. In the half of microvinifications pits were left, without cracking. Determinations of total phenolic content (TPC) were conducted using Folin-Ciocalteu method. Antiradical activity estimated by DPPH method, while FRAP method was also applied. Selected phenolic compounds were quantified by UPLC TQ-MS/MS. The TPC for the cherry wines were in interval 1552-1787 mg GAE/L while FRAP was 45.3 – 73.5 mmol/L Fe2+. The IC50 anti DPPH radical activity was from 3.8 to 7.2%. Also, were quantified compounds which exhibit antioxidant properties which are hydroxybenzoic acid derivatives, such as vanillic, gallic, protocatehuic and parahydroxybenzoic acid. The obtain results indicate that cherry wine is good source of antioxidant compounds. Antioxidant properties and quantity of phenolic compounds depends from the technological process applied in the production of fruit wines. Cherries and their derived products have beneficial health effect for overall health.Nutraceuticals in balancing redox status in ageing and age-related diseases WGs Meeting of the NutRedOx COST Action CA16112 Belgrade, March 2-3, 202

Phenolic profile of some fruit wines and their antioxidant properties

The composition and content of individual phenolic compounds in various fruit wines and overall antioxidant properties of these fruit wines were studied. Phenolic compounds were separated by reverse phase (RP) HPLC techniques, and their content was determined by means of mass spectrometer (MS) with triple quadrupole (TQ) analyser, which recorded specific precursor-product transitions. Antioxidant activity was monitored by the following spectrophotometric methods: DPPH, FRAP and Folin-Ciocalteu assay, respectively. Four types of berries (raspberry, blackberry, chokeberry and blueberry), one type of pome (apple) and one type of stone fruit (cherries) were used for the production of fruit wines. Corresponding fruit wines were produced by microvinification with or without adding sugar into the must before fermentation. Increase in alcohol level was responsible for the increased content of phenolic compounds in fruit wine due to improved extraction conditions. Produced fruit wines were preserved by adding SO2 which interferes with the determination of antioxidant activity of phenolic compounds. In this case, the development of a correlation method based on FRAP assay was introduced. Fruit wines are a rich source of substances which show beneficial effects on human health. Depending on the fruit type, different antioxidant compounds were predominant in wine samples

Efficiency of alfalfa hay mowing machines under the dryland conditions

This paper presents the tests results of three types of hay mowing machines (later in text: mowers), namely a self-propelled oscillatory mower-conditioner and two tractor-mounted mowers with oscillatory and rotary blades, used to mow alfalfa grown under dry land conditions in the region of central Serbia during three seasons in 2014, 2015 and 2016. Although characterized by older design, they are still commonly used at smaller and medium size farms in this region. Therefore, their optimal exploitation parameters are still of large importance for hay quality and production efficiency and sustainability. The exploitation parameters of all three mowers generally increased linearly with higher speeds, having high R2 values (over 0,8), with rare exceptions. The regression coefficients b clearly showed that the self-propelled mower-conditioner achieved maximum increase in production performance (b = 0,3606), compared with the oscillatory (b = 0,1158) and rotary mowers (b = 0,1414). Mower design had a significant (p ≤ 0,001) effect on cutting and chopping losses, production performance, and specific fuel consumption (p ≤ 0,05). The tests confirmed the superiority of the self-propelled mower over the two mowers aggregated with tractors

Experimental and numerical study of globe valve housing

Complex structure experimental analysis has always been a huge challenge for researchers. Conventional experimental methods (e.g., strain gauges) give only limited data sets regarding measurement on critical areas with high geometrical discontinuities. A 3D Digital Image Correlation method is an optical method that overcomes the limitations of conventional methods and enables full-field displacement and strain measurement of geometrically complex structures. System Aramis, based on Digital Image Correlation method, is used for experimental analysis and numerical model verification in this paper. Investigated complex structure is sphere/cylinder junction on globe valve housing subjected to axial loading. The highest experimentally measured von Mises strain values around 0.15% are recorded on cylinder/sphere intersection. Von Mises strain values on cylindrical and spherical part are several times smaller than on intersection itself. It is important to emphasize that, to the authors best knowledge, this is the first paper showing experimental results of 3D full and strain field of geometrically complex structure (sphere/cylinder intersection) on the intersection itself on pressure equipment. It is proven that 3D Digital Image Correlation method is fast and versatile method for recording strain during loading of complex structures

Karakteristike legura Ni-W elektrohemijski taloženih konstantnom i pulsirajućom strujom

The Ni-W alloys were electrochemically deposited from a ammonia-citrate electrolyte on rotation disc electrode with a replaceable steel disc, by direct and pulsed current. The aim of the paper is investigations of parameters of deposition, structure of alloys and temperature treatment on morphology and micro hardness of alloys.Prevlake legure Ni-W su elektrohemijski taložene iz amonijačno-citratnog elektrolita, na rotirajuću disk elektrodu od čelika, konstantnom i pulsirajućom strujom. Cilj rada je ispitivanje uticaja parametara taloženja sastava legure i termičkog tretmana na morfologiju i mikrotvrdoću dobijenih prevlaka

Electrochemical synthesis and characterization of basic bismuth nitrate [Bi6O5(OH)3](NO3)5·2H2O: a potential highly efficient sorbent for textile reactive dye removal

A new method of synthesis was developed for the preparation of basic bismuth nitrate [Bi6O5(OH)3](NO3)5·2H2O (ECBBN). Electrochemical synthesis of the material was carried out by galvanostatic electrodeposition from an acidic Bi(III) solution on a Ti substrate and further thermal treatment in air at 200 °C. Characterization of ECBBN was conducted by employing SEM–EDX, N2 adsorption, XRD and FTIR, and its pI was also determined. The analyses showed that the material obtained was pure [Bi6O5(OH)3](NO3)5·2H2O. Morphologically, ECBBN aggregates were composed of crystals, some smaller than 50 nm. Electrochemically synthesized sorbent (ECBBN) was used for the removal of the textile dye Reactive Blue 19 (RB19) from deionized water and model solutions of polluted river water, and it showed considerably superior sorption performance compared to other inorganic sorbents synthesized by conventional methods reported in the literature. A kinetic study suggests that the sorption process is both under reaction and diffusion control. Equilibration of the sorption process was attained in several minutes, i.e. the sorption process is very fast. The sorption equilibrium data were well interpreted by the Langmuir, Redlich–Peterson and Brouers–Sotolongo isotherm. Using Langmuir isotherm, the maximum sorption capacity of ECBBN was reached at pH 2 and was 1049.19 mg g−1

Wine polyphenol resveratrol inhibits contractions of isolated rat uterus by activation of smooth muscle inwardly rectifying potassium channels

Resveratrol is a phytoalexin produced in a number of plant species including grapes. The benefit of resveratrol to health is widely reported. Resveratrol has been found to promote relaxation of non-pregnant and pregnant uterus, but its mechanism of action is unclear. The aims of our study were to investigate the involvement of inwardly rectifying potassium channels (Kir) in inhibitory effects of resveratrol on three models of contractions of non-pregnant rat uterus: the spontaneous rhythmic contractions (SRC), oxytocin-elicited phasic contractions and tonic oxytocin-elicited contractions. Uterine strips were obtained from virgin female Wistar rats in oestrus. Strips were mounted into organ bath for recording isometric tension in Krebs-Ringer solution. Experiments followed a multiple curve design. In order to test the involvement of Kirchannels in a mechanism of action of resveratrol (1-100 μM),BaCl2 (1 mM),a antagonist of inwardly rectifying potassium channels was used. Resveratrol induced a concentration-dependent relaxation of all models of contractions. BaCl2 antagonized the response to resveratrolon SRC and oxytocin-elicited phasic contractions. Relaxation achieved by resveratrolon tonic oxytocin-elicited concentrations was insensitive to BaCl2.The antagonism of resveratrol effects by inwardly rectifying potassium channels antagonist suggests that Kir channels are involved in resveratrol action on phasic contractions of rat uterus. Inhibitory effect of resveratrol on tonic contractions did not include Kir channels