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

Supplementary data for article: Sakan, S.; Dević, G.; Relić, D.; Anđelković, I.; Sakan, N.; Đorđević, D. Risk Assessment of Trace Element Contamination in River Sediments in Serbia Using Pollution Indices and Statistical Methods: A Pilot Study. Environmental Earth Sciences 2015, 73 (10), 6625–6638. https://doi.org/10.1007/s12665-014-3886-1

Supplementary material for: [https://doi.org/10.1007/s12665-014-3886-1]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/1701

Paralelo 36

The evaporation of droplets occurs in a large variety of natural and technological processes such as medical diagnostics, agriculture, food industry, printing, and catalytic reactions. We study the different droplet morphologies adopted by an evaporating droplet on a surface with an elliptical patch with a different contact angle. We perform experiments to observe these morphologies and use numerical calculations to predict the effects of the patched surfaces. We observe that tuning the geometry of the patches offers control over the shape of the droplet. In the experiments, the drops of various volumes are placed on elliptical chemical patches of different aspect ratios and imaged in 3D using laser scanning confocal microscopy, extracting the droplets shape. In the corresponding numerical simulations, we minimize the interfacial free energy of the droplet, by employing Surface Evolver. The numerical results are in good qualitative agreement with our experimental data and can be used for the design of micropatterned structures, potentially suggesting or excluding certain morphologies for particular applications. However, the experimental results show the effects of pinning and contact angle hysteresis, which are obviously absent in the numerical energy minimization. The work culminates with a morphology diagram in the aspect ratio vs relative volume parameter space, comparing the predictions with the measurements

Dynamics in the dimerised and high field incommensurate phase of CuGeO3_3

Temperature ($2.3<T<40$\ K) and magnetic field ($0<B<17$\ T) dependent far infrared absorption spectroscopy on the spin-Peierls coumpound CuGeO$_3$\ has revealed several new absorption processes in both the dimerised and high field phase of CuGeO$_3$. These results are discussed in terms of the modulation of the CuGeO$_3$\ structure. At low fields this is the well known spin-Peierls dimerisation. At high fields the data strongly suggests a field dependent incommensurate modulation of the lattice as well as of the spin structure.Comment: 12 pages (revtex), 2 figures (eps), csh selfextracting .uu file, To appear in PRB-Rapid Com

Effect of NaCl on seed germination in some Centaurium Hill. Species (Gentianaceae)

The influence of high NaCl concentrations on seed germination in both light and darkness was examined in the species Centaurium pulchellum, C. erythraea, C. littorale, C. spicatum, and C. tenuiflorum. Salt tolerance was found to depend on the life history of the seeds. To be specific, seeds of all five species failed to complete germination when exposed to continuous white light if kept all the time in the presence of 100-200 mM and greater NaCl concentrations. However, when after two weeks NaCl was rinsed from the seeds and the seeds were left in distilled water under white light for an additional two weeks, all species completed germination to a certain extent. The percent of germination not only depended on NaCl concentration in the prior medium, but was also species specific. Thus, seeds of C. pulchellum, C. erythraea, and C. littorale completed germination well almost irrespective of the salt concentration previously experienced. On the other hand, seeds of C. tenuiflorum completed germination poorly if NaCl concentrations in the prior media were greater than 200 mM. When seeds after washing were transferred to darkness for an additional 14 days, they failed to complete germination if previously imbibed on media containing NaCl concentrations greater than 400 mM. However, the seeds of all species, even if previously imbibed at 800 mM NaCl, could be induced to complete germination in darkness by 1 mM gibberellic acid. .Uticaj visokih koncentracija NaCl na klijanje semena, kako na svetlosti tako i u tami, ispitivano je kod vrsta Centaurium pulchellum, C. erythraea, C. littorale, C. spicatum i C. tenuiflorum. Tolerantnost ovih biljaka na natrijum-hlorid zavisi od životnog ciklusa semena. Zapravo, semena svih pet ispitivanih vrsta nisu završavala klijanje kada su bila izložena kontinuelnoj beloj svetlosti u prisustvu 100-200 mM i pri većim koncentracijama. Pored toga, semena svih ovih vrsta, izložena imbibiciji na 800 mM NaCl, mogla su biti indukovana da završe klijanje u mraku uz dodatak 1 mM giberelinske kiseline. .nul

Revival of the spin-Peierls transition in Cu_xZn_(1-x)GeO_3 under pressure

Pressure and temperature dependent susceptibility and Raman scattering experiments on single crystalline Cu_xZn_(1-x)GeO_3 have shown an unusually strong increase of the spin-Peierls phase transition temperature upon applying hydrostatic pressure. The large positive pressure coefficient (7.5 K/GPa) - almost twice as large as for the pure compound (4.5 K/GPa) - is interpreted as arising due to an increasing magnetic frustration which decreases the spin-spin correlation length, and thereby weakens the influence of the non-magnetic Zn-substitution.Comment: LaTeX, 15 pages, 5 eps figures, Phys. Rev. B, to appea

Supplementary data for article: Sakan, S.; Dević, G.; Relić, D.; Anđelković, I.; Sakan, N.; Đorđević, D. Risk Assessment of Trace Element Contamination in River Sediments in Serbia Using Pollution Indices and Statistical Methods: A Pilot Study. Environmental Earth Sciences 2015, 73 (10), 6625–6638. https://doi.org/10.1007/s12665-014-3886-1

Supplementary material for: [https://doi.org/10.1007/s12665-014-3886-1]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/1701

Photoactivity of Immobilized Titanium Dioxide (TiO2 ) in Lindane Degradation

Introduction and study objectives: Lindane is a generic name for γ-hexachlorocyclohexane, one of the isomers from the group of Hexachlorocyclohexanes (HCH) [1]. Due to its neurotoxic activity, it had a very wide application, from agricultural to non-agricultural purposes. As a result of its lipophility, lindane can easily pass through the blood-brain barrier. The reason of his neurotoxicity is that it can interact with GABAA receptors and obstruct GABA neurotransmitter signaling in nervous system. People who have been exposed to lindane for a long time can experience serious health problems, such as: poor liver function, cardiac arrhythmias, and irregular menstruation. Due to its adverse health effect, lindane is classified as a “pregnancy category C” chemical [2]. It is also one of the Persistent Organic Pollutants (POPs) that were listed under the Annex A (elimination) of the Stockholm Convention with a specific exemption for use as a human health pharmaceutical [3]. The aim of this paper was the assessment of the immobilized titanium dioxide photocalytic properties in lindane degradation. Methodology: Spray pyrolysis method was used for a synthesis of thin titanium oxide films on the foils of the stainless steel [4]. The lindane solution was incubated with TiO2 and exposed to UV/VIS light. Aliquots were taken from the reaction mixture after 0, 2, 4, 6, 8, 10 and 12 hours. Lindane was extracted according to the EPA method 505 [5], and analyzed using an Agilent 7890A gas chromatograph (GC) connected to an electron capture detector (ECD). The GC was equipped with a Thermo Scientific™ TraceGOLD™ TG-5MT capillary column (60 m × 0.25 mm ID × 0.25 μm). The temperature program used for gas chromatography was: Initial heating temperature: 50 °C for 3 minutes, then heating at a rate of 30 °C/min to 210 °C for 20 minutes. Hydrogen with a flow rate of 60 mL/min was used as the carrier gas. Results and conclusions: Photoactivity of immobilized titanium dioxide in the degradation of lindane was measured as a percentage of lindane’s degradation compared to its initial concentration. The obtained results demonstrated that after two hours 45.32 % of lindane was degraded, while after twelve hours the percentage of degradation increased to 98.20 %. In this study we proved that the immobilized titanium dioxide can be used as a productive and fast photocatalyst for lindane photodegradation