bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synergistic cytotoxic effect of tetrachlorocatechol and sodium azide in Escherichia coli: Toxicity, metabolism, and mechanistic aspects
Authors: Levy Smadar , Chevion Mordechai 
Published: February 2009

Abstract
Pentachlorophenol (PCP) is used in industrial and domestic applications, including as a biocide and a wood preservative. Metabolism of PCP undergoes oxidative dechlorination, forming tetrachlorocatechol (TCC) and tetrachlorohydroquinone (TCHQ). Both sodium azide (NaN3) and TCC appear naturally in soil. None of them are cytotoxic by themselves or facilitate autooxidation. Here, we show that their combination leads to synergistic cytotoxicity (&gt;6 log bacterial killing) to Escherichia coli. The rate of oxygen consumption in a cell-free system showed that NaN3 increases TCC oxidation by 520-fold. The synergism coefficient to cells was calculated as 96 or greater, and we have shown the formation of a new compound. It is suggested that the intermediate species, o-tetrachlorosemiquinine, and an unknown, nitrogen-centered free radical, both visualized by electron-spin resonance, are harmful species responsible for the synergistic cytotoxicity of TCC/NaN3, rather than the endproduct formed during the reaction. Desferoxamine and 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide offered nearly complete protection, but through radical scavenging rather than through chelating properties. The mechanism of damage for TCC compared to its analogue, TCHQ, were investigated, and whereas the cellular damage of TCHQ/NaN3 is through a site-specific mechanism, in the case of TCC/NaN3 it is through the accumulation of the component(s) in the bacterial cell membrane, eventually leading to dysfunction, as evidenced by electron microscopy.
Pseudospin symmetry and a double ring-shaped spherical harmonic oscillator potential
Authors: Zhang Min-Cang 
Published: February 2009

Abstract
A new double ring-shaped spherical harmonic oscillator potential is presented. The pseudospin symmetry in this system is investigated by solving the Dirac equation with equal mixture of scalar and vector potentials with opposite signs. The normalized spinor wave function and energy equation are obtained and some particular cases are discussed.
Liquidus surface projection of the Fe–Co–C ternary system in the iron-rich corner
Authors: Haddad Farida , Eddine Amara Sif , Kesri Rafika 
Published: February 2009

AbstractIn the present work, the liquidus projection of the Fe – Co – C ternary system is plotted in the iron-rich corner using differential thermal analysis, optical microscopy, scanning electron microscopy and X-ray diffraction. This projection contains three primary crystallisation phases (δ(Fe), γ(Fe) and graphite) as well as two univariant lines: peritectic L + δ(Fe) γ(Fe) and eutectic L γ(Fe) + Cgraphite.
Catalytic performance of Fe-, Pd-, and Pd–Fe- mordenites in simulated hydrocarbon-selective catalytic reduction of N2O by methane in a model flue-gas from nitric acid plants
Authors: Lee Sungkyu , Hye Seo Min , Cho Sung-Su , Kang Kyoung-Hoon , Kim Jong-Min , Seon Hong Hyun , Yun Yongseung , Ahn Jae-Hwan 
Published: February 2009

AbstractThis paper reports on the individual activity and selectivity of Fe-, Pd- and Pd – Fe-mordenite catalysts prepared by wet Fe-ion exchange and Pd-ion impregnation for N2O reduction using simulated hydrocarbon-selective catalytic reduction operation conditions of nitric acid plants. Laboratory-scale data on the activity, selectivity and characterization of Fe-, Pd-, and Pd – Fe-mordenite catalysts for conversion of N2O have been obtained under the simulated hydrocarbon-selective catalytic reduction operating condition in the temperature range of 325 – 400 °C encountered in nitric acid plant tail gases. More specifically, Pd-, Fe- and Pd – Fe-mordenite catalysts with Si/Al ratios of 10.25 – 10.65 were prepared. Wet ion-exchange methodology was used to prepare Fe-mordenite catalyst, whilst Pd-ion impregnation was used to prepare Pd-, and Pd – Fe-mordenite catalysts. Catalytic activities could not be consistently correlated with and explained by X-ray absorption near edge spectroscopy spectra. Further analysis by temperature-programmed desorption of ammonia was performed to explain higher catalytic activity of Pd – Fe-mordenite compared to Fe-, and Pd-mordenites. Higher catalytic activity of Pd – Fe-mordenite is most probably attributable to the presence of strong Lewis type acid centers as manifested by a TPD spectrum peak at about 300 °C.
Microstructure and some properties of FeCr25Co15 alloy subjected to plastic deformation by complex load
Authors: Korneva Anna , Bieda Magdalena , Korznikowa Galija , Sztwiertnia Krzysztow , Korznikov Aleksandr 
Published: February 2009

AbstractThe microstructural, mechanical and magnetic properties of FeCr25Co15 alloy were examined after upset followed by torsion. Deformation was carried out at temperatures that corresponded to the appearance of α + γ phases. During the process, the initial lamellar microstructure of the material was transformed into a globular one. In the sample sections parallel to the upsetting direction a gradient microstructure, with a layer of submicron grains in the highest deformation zone, was formed. The thickness of the zone did not significantly depend on the deformation temperature. Measurements of the mechanical properties after magnetic treatment showed that the plasticity and strength of the deformed samples increased in comparison with the high coercive state.
The effect of cooling rate on the microstructure and mechanical properties of Mg–Zn–Gd-based alloys
Authors: Liu Yong , Yuan Guangyin , Yin Jian , Lu Chen , Ding Wenjiang , Jiang J. Z. 
Published: February 2009

AbstractThe microstructure and mechanical properties of Mg3.5Zn0.6Gd and Mg3.5Zn0.6Gd1.5Cu alloys were investigated under different solidification conditions. The microstructure and phase constitutions of alloys were characterized using optical microscopy, scanning electron microscopy, X-ray diffraction and differential thermal analysis. The results indicate that the cooling rate plays an important role in grain refinement and phase constitutions of Mg – Zn – Gd alloys. In the cooling rate range from 4.8 K s− 1to 18.5 K s− 1for the Mg – Zn – Gd system, higher content of the icosahedral phase (I-phase) was obtained under the condition of higher cooling rate which accelerated the nucleation and growth of the I-phase. Under the cooling rate of 18.5 K s− 1, the mechanical properties of the Mg3.5Zn0.6Gd alloy were further improved by the high I-phase content due to its unique icosahedral structure, in addition to the contribution of grain refinement.
Study of fatigue dislocation structures in [233] coplanar double-slip-oriented copper single crystals using SEM electronic channelling contrast
Authors: Zhou Yang , Li Xiao-Wu , Yang Rui-Qing 
Published: February 2009

Abstract
Dislocation structures in fatigued [] coplanar double-slip-oriented copper single crystals were studied using the electron channelling contrast technique in scanning electron microscopy, especially focusing on the observations of the microstructures of persistent slip bands and deformation bands. It was found that, at low plastic strain amplitudes (γpl ≤ 3.4 × 10– 4), the dislocation structures of the [] copper single crystal comprise a majority of elongated veins and a few elongated cells along the primary slip plane (111). As γpl increases to 6.2 × 10– 4, a special persistent slip band structure consisting of irregular dislocation cells, rather than generally-observed ladders in single-slip crystals, was found to form, which is responsible for the occurrence of a quasi-plateau in the cyclic stress – strain curve of the [] crystal. When γpl ≤ 3.5 × 10– 3, different dislocation microstructures in deformation bands, such as wall-like features, dislocation walls, elongated cells and dense dislocation cells, were found in the cyclically saturated [] crystal. Effects of the crystallographic orientation, the applied plastic strain amplitude, the accumulated plastic strain and the strain localization in the crystal on the microstructure of deformation bands are summarized and discussed.
σ-phase morphologies and their effect on mechanical properties of duplex stainless steels
Authors: Pohl Michael , Storz Oliver , Glogowski Thomas 
Published: February 2009

Abstract
The aim of the presented study is to investigate the influence of the different σ-phase morphologies on the mechanical, wear and corrosive behaviour of the duplex stainless steel 1.4462 (X2CrNiMoN 22 5 3). Different amounts of σ-phase were precipitated in tensile, impact strength, wear and corrosion samples by annealing at 750 °C, 850 °C and 938 °C. σ-phase shows a detrimental influence on the impact strength and the corrosion behaviour. To a very limited extent it can be used to slightly raise the strength under quasi-static load and to improve the wear resistance. Finally, it can be concluded that σ-phase has more unfavourable influences on the material' behaviour than advantageous ones. Therefore, it should be avoided in duplex stainless steels.
Microstructural and acoustic damage analysis and finite element stress simulation of air plasma-sprayed thermal barrier coatings under thermal cycling
Authors: Trunova Olena , Bednarz Piotr , Herzog Roland , Beck Tilmann , Singheiser Lorenz 
Published: February 2009

Abstract
Degradation evolution and failure mechanisms of air plasma-sprayed thermal barrier coatings during thermal cycling were investigated using microstructural and acoustic emission analysis. The microcrack evolution observed suggests that the life-time is governed by the kinetics of crack formation, growth and linking of individual cracks. The damage in the thermal barrier coatings mainly occurs during cooling due to thermal-expansion mismatch stresses at the metal – ceramic interface. The effect of the minimum cycling temperature on the lifetime was found to be much more pronounced than that of a variation in cooling rate. Experimental results were supported by finite element modeling of the stress distribution at the metal – ceramic interface during cooling at different rates.
Thermal, mechanical and fretting fatigue of silicon nitride
Authors: Schwind Thomas , Schalk Thomas , Kerscher Eberhard , Beck Tilmann , Lang Karl-Heinz , Löhe Detlef 
Published: February 2009

Abstract
Tools for hot wire rolling are exposed to high thermal, mechanical and tribological loadings during service. Ceramic materials such as silicon nitride possess good mechanical and tribological properties up to temperatures where most of today' roller materials do not exhibit acceptable reliability. In the present paper basic mechanical properties under thermal and mechanical loading as well as the damage behaviour of Si3N4 have been investigated in high cycle thermal fatigue and dynamic as well as cyclic four point bending tests. In fretting fatigue tests the behaviour of Si3N4 under near-service conditions, as they appear during application in the hot wire rolling process, has been analysed. It is shown that in the temperature range investigated pure thermally induced loading leads to the same damage mechanism as pure mechanical loading and therefore thermally induced stresses can be directly added to any mechanical loading. The isothermal four point bending tests confirm the existence of a cyclic fatigue effect. With the fretting fatigue experiments the limits of high-performance ceramics such as Si3N4 are shown. Under the complex loading, surface flaws are produced leading to a severe lifetime reduction compared to plain mechanical and thermal loading.
Innovative materials for energy technology
Authors: Möslang Anton , Adelhelm Christel , Heidinger Roland 
Published: February 2009

Abstract
High performance materials are indispensable for economical and environmentally acceptable operation of fusion power and innovative fission reactor systems. In order to provide materials design data for short term needs of the ITER Test Blanket Modules and for a Fusion Demonstration Reactor, the international fusion materials community is concentrating their R&D work mainly on the four reduced-activation structural materials 8 – 9 CrWTa ferritic/martensitic steels, V – Ti – Cr alloys, W alloys and SiCf/SiC composites as well as on functional materials such as CVD diamond windows. Besides the development of the European reduced activation reference steel EUROFER, emphasis will be placed on synergies between fusion and fission materials R&D, namely the development of ductile oxide dispersion strengthened ferritic/martensitic steels with nano-scaled Y2O3 or Y2Ti2O7 particles that increase not only high temperature strength but also substantially the microstructural stability against irradiation embrittlement and high temperature ageing. Finally, the corrosion behaviour of zirconium-1.5 wt.% tin alloy, a well established cladding material for nuclear fuel rods, will be shown in different environments.
Investigation of surface fatigue of thermally sprayed micro- and nanocrystalline cylinder wall coatings by means of cavitation testing
Authors: Hahn Mareike , Fischer Alfons 
Published: February 2009

Abstract
The future demands of diesel engines require new options for low-friction and wear-resistant materials in order to increase efficiency and achieve environmentally sound solutions. Efforts are made to improve the performance and reduce the weight of engine blocks by coating the aluminium cylinder bores using thermal-spray processes. Thus, along with other means, today nanocrystalline coatings are considered when looking for the desired combination of structural, productional, and topographical properties. Besides sufficient tribological properties it is important that the composite (base material and coating) allows for prolonged endurance under cyclic mechanical and thermal stresses. Prior to engine tests these coatings are characterised in the laboratory by means of bench tests for adhesive tensile strength, tribological properties and fatigue of the composite. Cavitation tests should reveal the tribological stability of these coatings and their ability to resist high-frequency cyclic impact stresses. The objective in this investigation is to describe the cavitation behaviour and the influence of voids such as pores or oxides.
The running-in of amorphous hydrocarbon tribocoatings: a comparison between experiment and molecular dynamics simulations
Authors: Pastewka L. , Moser S. , Moseler M. , Blug B. , Meier S. , Hollstein T. , Gumbsch P. 
Published: February 2009

Abstract
Amorphous hydrocarbon (a-C: H) films have enormous potential as low friction, wear resistant coatings. Here, we present a plasma assisted chemical vapour deposition process for a-C: H that exhibits growth rates of 100 nm min– 1 and higher. The tribological performance of the resulting a-C: H films has been studied experimentally by reciprocating sliding of an a-C: H-coated Si3N4 ball on an a-C: H-coated 100Cr6 steel substrate and by subsequent micro Raman spectroscopy of the wear track. Running-in of the coatings is observed and characterised by a rapid decrease in the friction coefficient accompanied by a significant increase in sp2 hybridisation in the wear track. In order to gain a deeper understanding of the underlying running-in mechanisms, the sliding of two a-C: H films under a load of 5 GPa has been studied by classical molecular dynamics employing a range-corrected Brenner bond-order potential. The simulations reproduce the experimental trends and explain the running-in by a combination of smoothing and chemical passivation of both tribosurfaces. Consequently, both mechanisms should be controlled in order to produce tribological coatings for applications with optimum energy-efficiency.
Development of high power density cathode materials for Li-ion batteries
Authors: Ketterer Bernt , Vasilchina Hristina , Seemann Klaus , Ulrich Sven , Besser Heino , Pfleging Wilhelm , Kaiser Tatjana , Adelhelm Christel 
Published: February 2009

Abstract
Cathode material for Li-ion batteries can be synthesised by r.f. magnetron sputtering of LiCoO2 targets in a pure Ar plasma. This technique is suitable for large-scale implementation in foil coating set-ups. By choosing the process parameters and by employing post heat treatment nanocrystalline, stoichiometrical LiCoO2 films can be fabricated which exhibit the desired high temperature phase. The determination of the elementary composition is possible by optical emission spectroscopy including plasma stimulation and carrier gas temperature extraction. The proof of crystal structure is carried out by X-ray diffraction and Raman spectroscopy. Heat treatment can be conventionally realised in a furnace or by laser impact. With regard to increasing the power density, the surface of the cathode material can be enhanced six-fold by laser-assisted surface patterning.
Determination of v–K curves from lifetime tests with reloaded survivals
Authors: Fett Theo , Riva Marco , Hoffmann Michael J. , Oberacker Rainer , Munz Dietrich 
Published: February 2009

Abstract
Lifetime tests under static load are often carried out in order to determine the relation v(K) of subcritical crack growth. Depending on the scatter behaviour of the most serious cracks in a specimen a number of immediate failures can occur during load application and some specimens will not fracture within a certain maximum lifetime limit. In order to get additional information on subcritical crack growth behaviour, the authors recommend performing lifetime tests at an increased load level. Appropriate procedures for the evaluation of such tests will be outlined. First, the procedure is explained for the simple case of the power-law crack growth relation. Then, a modified lifetime evaluation is proposed that needs no special crack growth law. The methods described are applied to static lifetime measurements on SiAlON in distilled water at 20 °C as the environment.
Tensile properties of L12 intermetallic foils fabricated by cold rolling
Authors: Kaneno Yasuyuki , Myoki Tadamichi , Takasugi Takayuki 
Published: February 2009

Abstract
Polycrystalline L12-type Ni3(Si,Ti), Ni3Al and Co3Ti alloys prepared through thermomechanical processing from arc-melted ingots were successfully cold-rolled to thin foils with a thickness of less than 200 m. The cold-rolling with over 90 % reduction in thickness was possible without providing intermediate annealing. The cold-rolled foils showed high tensile strength (∼2 GPa) at room temperature although no plastic elongation was observed. The tensile strength of the annealed foils generally decreased acquiring a certain level of fracture strain. Room temperature fracture strain increased with increasing annealing temperature, and reached to 30 – 40 % by a high temperature annealing at 1173 K. Among three kinds of intermetallic alloys, the Ni3(Si, Ti) foil annealed around at 900 K exhibited an extremely high tensile strength and yield strength (over 2 GPa) with a reasonable fracture strain. Also, it was found that the fully-recrystallized Ni3(Si, Ti) and Co3Ti foils showed a strength anomaly at intermediate testing temperature. The observed tensile properties, especially tensile strength at low temperature as well as at high temperature for the present L12 intermetallic foils, were found to be superior to those for the conventional alloys such as nickel based alloys and stainless steels.
Microstructure and room temperature mechanical properties of Hf and Sn-doped Nb-20Ti-5Cr-3Al-18Si alloy
Authors: Guo J. T. , Tian Y. X. , Sheng L. Y. , Zhou L. Z. , Ye H. Q. 
Published: February 2009

Abstract
In this paper, the effects of Sn and Hf additions on microstructures and room temperature mechanical properties of Nb-20Ti-5Cr-3Al-18Si alloy were investigated. The Sn addition has no significant effect on the microstructure of the alloy. Sn is preferentially partitioned in (Nb, Ti)ss rather than (Nb, Ti)5Si3. The addition of Sn decreases the solubility of Cr in (Nb, Ti)ss. The addition of Hf causes coarsening of the eutectic structure of (Nb, Ti)ss and (Nb, Ti)5Si3 and the formation of the Hf-rich γ(Nb, Ti)5Si3 along phase boundaries. With the addition of Sn the strength of the alloy decreases, while its ductility increases slightly. The Hf addition simultaneously improves strength and ductility of the alloy. The relationships between composition, microstructure and properties are discussed.
Transient dopant segregation and precipitation in yttrium-doped alumina
Authors: Gülgün Mehmet A. , Šturm Sašo , Cannon Rowland M. , Rühle Manfred 
Published: February 2009

Abstract
Ultra-pure AI2O3 ceramics doped with 2000 ppm of Y2O3 were sintered at 1500 °C or 1650 °C for 2 or 12 h. The re-sulting microstructure consisted of alumina matrix grains and second-phase precipitates. Y-doped alumina samples sintered at 1550 °C for shorter times (<2 h) contained primarily YAIO3-YAP precipitates. This is in contradiction of the binary equilibrium phase diagram for AI2O3 and Y2O3, which predicts Y3AI5O12- YAG to be the first phase to appear, as the Y-concentration exceeds the solubility limit of α-A12O3. The formation of YAG in co-existence with the YAP precipitates was observed in samples sintered at 1550°C for 12h and 1650°C for 2 h. The excess of yttrium in the grain boundary was 5.5 ± 0.9 Y-atoms/nm2 for the specimen containing primarily YAP and 4.2 ± 1.2 Y-atoms/nm2 in samples where YAP and YAG co-existed. The study demonstrates that in samples containing multiple precipitates, the grain-boundary excess concentration of Y atoms is controlled by the composition of the precipitates.
A study of phase equilibria in the Al-rich part of the Al-Mn alloy system
Authors: Grushko Benjamin , Balanetskyy Sergiy 
Published: February 2009

Abstract
Following new findings by Y. Du et al. (Int. J. Mater. Res. 98 (2007) 855), the Al-Mn phase diagram was re-examined in the compositional range of ∼4 to 27 at.% Mn using scanning and transmission electron microscopy, energy-dispersive X-ray analysis and differential thermal analysis. The corrections to the Al-Mn phase diagram concerning the reactions involving the Al6Mn and Al4Mn phases reported in the above-mentioned contribution were not confirmed. Instead, our results were in agreement with those reported earlier by Murray et al. (Metall. Trans. A18 (1987) 385): the reaction Al6Mn + μ ↔ λ occurs at 695 °C, and L + μ ↔ Al6Mn at 705 °C. At higher Al concentrations, the reactions μ ↔ L + T, μ + v ↔ T and T ↔ L + γ1 were revealed at ∼923, 913°C and 1001 °C, respectively, in good agreement with the literature data.
Kinetic effects during phase transitions of the Al-Mn alloys are discussed on the basis of experimental results.
Interpretation of inorganic melts' surface properties on the basis of chemical status and structural relations
Authors: Dudek Rostislav , Dobrovsky Ludovit , Dobrovskâ Jana 
Published: February 2009

Abstract
This article is devoted to experimental investigation of the influence of chemical composition on surface properties of inorganic oxidic systems. Through its contents it belongs to a broader area of investigation of systems that form a basis of refining metallurgical slags. The experiment itself was realised on equipment using the sessile drop method modified for high temperatures. The results were compared with theoretical concepts about intrinsic structural relations in melts. Due to the occurrence of anomalies in the temperature dependence of surface tension in the systems investigated and ensuing disagreement with theories, we have used high-temperature X-ray phase analysis. This analysis determined precipitation of individual phases during thermal load and added information for theoretical exploration and consideration about physico-chemical properties of melts working only with binary or ternary systems.