179 research outputs found

    Deformation Induced Lattice Misorientation in Lath Martensite

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    Effect of plastic deformation on the lattice misorientation in lath martensite was investigated by Electron Backscatter Diffraction (EBSD). As-quenched rod-like specimens were plastically deformed until 9000 N, 14000 N, 19000 N and 21000 N of tensile loading. Grain average misorientation maps were collected by EBSD. It was shown that the average misorientation during plastic deformation increased from 0.887 to 1.156 degrees. Results showed that the density of geometrically necessary dislocations, which caused the lattice misorientation, slightly increased during plastic deformation of lath martensite

    The Effect of Multiaxial Forging on the Grain Refinement of Low Alloyed Steel

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    Ultra fine grained low carbon low alloyed steel was formed by multiaxial forging. Altogether five passes of forging were made with decreasing temperature. The first two passes happened in the austenitic state of the steel, the third was made at the austenite-ferrite transition temperature. The fourth occurred in the austenitic-ferritic region, while the last pass was made in pure ferritic state. The intensive plastic deformation caused the austenite-ferrite transition temperature to be lowered, thus the undercooling was larger, and very small ferritic cores were produced. The following deformation made the grain structure even more fine

    Effect of leaser treatment on the surface of cast iron cylinder bores

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    The environmental and pollution materials emission standards in Europe are going to be more strict. In order to meet the standards, a European automotive manufacturer performs a finishing laser treatment on the honed cast iron cylinder bores of their V-engine blocks. Samples of laser treated cast iron cylinder bores with lamellar graphite were investigated. Due to the growing popularity and high efficiency of fiber lasers, samples treated with Yb-fiber lasers were investigated. In order to evaluate the microstructure and grain size of the laser treated layer, scanning electron microscopic images were taken on cross sectioned samples with a scanning electron microscope/focused ion beam dual beam electron microscope. The samples were found to be ultra fine grained. Nanoindentation hardness measurements of the surface layer showed a clear linear trend between the laser power density in the applied range and the measured hardness. Additional micro hardness measurements suggest an annealed region beneath the surfa ce

    Measuring the effects of some laser parameters on the surface and near surface region of laser treated cast iron cylinder bore

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    The environmental and polluting materials emission standards in Europe are going to be always stricter, so in order to keep up with them, one of the largest European automotive manufacturers performs a laser treatment on the cylinder bores of their combustion engines. In this article the laser treated layers of cast iron cylinder bores with lamellar graphite are investigated with a FISCHERSCOPE^\unhbox \voidb@x \hbox \textregistered HM2000 XY microhardness measurement system and with a FEI Nova Nanolab 600 SEM/FIB dual beam scanning electron microscope (SEM), equipped with focused Ga-ion beam source. Four samples treated by two different laser sources in three configurations were investigated

    Noncommutative Common Cause Principles in Algebraic Quantum Field Theory

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    States in algebraic quantum field theory "typically" establish correlation between spacelike separated events. Reichenbach's Common Cause Principle, generalized to the quantum field theoretical setting, offers an apt tool to causally account for these superluminal correlations. In the paper we motivate first why commutativity between the common cause and the correlating events should be abandoned in the definition of the common cause. Then we show that the Noncommutative Weak Common Cause Principle holds in algebraic quantum field theory with locally finite degrees of freedom. Namely, for any pair of projections A, B supported in spacelike separated regions V_A and V_B, respectively, there is a local projection C not necessarily commuting with A and B such that C is supported within the union of the backward light cones of V_A and V_B and the set {C, non-C} screens off the correlation between A and B

    Formation of surface layer on cast iron cylinder bore due to nanosecond laser impulses

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    The air pollution emission standards for automobiles are going to be more strict worldwide. European automotive manufacturer makes a laser treatment on the cast iron cylinder bores of the V-engine blocks. Samples of laser treated cast iron cylinder bore with lamellar graphite were investigated. Seven samples were treated with XeCl-excimerlaser, Nd-YAG laser and Yb-fiber laser sources. In order to evaluate the microstructure and grain size of the laser treated layer, scanning electron microscopic (SEM) images were taken in cross section with a SEM/focused ion beam (FIB) dual beam electron microscopes. All the samples were found to be ultra fine grained. To simulate the heating conditions during laser treatment, finite element method (FEM) simulations were made for the different lasertypes. Additional X-ray diffraction measurements showed retained austenite after laser treatment

    PopulĂĄciĂłgenetikai paramĂ©terek, tenyĂ©szĂ©rtĂ©kek, fenotĂ­pusos Ă©s genetikai trendek limousin tehenek elsƑ ellĂ©si Ă©letkorĂĄra

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    Some environmental effects, population genetic parameters, breeding value of Limousin breeding bulls, also phenotypic and genetic trends in the age at first calving (AFC) of cows between 1992 and 2013 were estimated. Data were served by the Limousin and Blonde d’Aquitaine Breeders Association, in Hungary. The study was extended to three herds and 1157 cows. GLM method was used for the study of different effects, the BLUP animal model for estimation of population genetic parameters and breeding values (BV), and one-way linear regression analysis for trend calculations. The overall mean value of the AFC was estimated to be 34.7±0.4 months. The contribution of the evaluated factors to the phenotype was as follows: herd 73.51%, birth year of cow 13.02%, sire 6.74%, birth season of cow 1.62%. The heritability of AFC proved to be low (h2 = 0.08±0.07 and h2 = 0.01±0.04). There were relatively small differences in the estimated BV of the studied sires for the AFC. Based on the phenotypic trend calculation, the AFC of cows decreased by an average of 0.33 months per year, however no significant change was found in the genetic trend during the study period.A SzerzƑk a Limousin Ă©s Blonde d’Aquitaine TenyĂ©sztƑk EgyesĂŒletĂ©nek orszĂĄgos adatbĂĄzisĂĄt felhasznĂĄlva nĂ©hĂĄny környezeti tĂ©nyezƑ hatĂĄsĂĄt vizsgĂĄltĂĄk limousin tehenek elsƑ ellĂ©si Ă©letkorĂĄra vonatkozĂłan 1992 Ă©s 2013 között. A munka sorĂĄn az elsƑ ellĂ©skori Ă©letkor populĂĄciĂłgenetikai paramĂ©tereit, a tenyĂ©szbikĂĄk tenyĂ©szĂ©rtĂ©kĂ©t, valamint a tulajdonsĂĄg fenotĂ­pusos Ă©s genetikai trendjĂ©t is megbecsĂŒltĂ©k. A munkĂĄt hĂĄrom nagy tehĂ©nlĂ©tszĂĄmmal rendelkezƑ tenyĂ©szetre Ă©s 1157 tehĂ©nre terjesztettĂ©k ki. A környezeti tĂ©nyezƑk hatĂĄsĂĄnak vizsgĂĄlatĂĄra GLM (univariate analysis of variance) eljĂĄrĂĄst, a populĂĄciĂłgenetikai paramĂ©terek Ă©s tenyĂ©szĂ©rtĂ©kek meghatĂĄrozĂĄsĂĄra BLUP egyedmodellt, a fenotĂ­pusos Ă©s genetikai trend szĂĄmĂ­tĂĄsĂĄhoz egytĂ©nyezƑs lineĂĄris regressziĂł analĂ­zist hasznĂĄltak. Az elsƑ ellĂ©si Ă©letkor ĂĄtlaga 34,7±0,4 hĂłnap volt. A környezeti tĂ©nyezƑk szerepe a fenotĂ­pus kialakĂ­tĂĄsĂĄban a következƑkĂ©pp alakult: tenyĂ©szet 73,51%, szĂŒletĂ©si Ă©v 13,02%, apa 6,74%, szĂŒletĂ©si Ă©vszak 1,62%. Az elsƑ ellĂ©skori Ă©letkor tulajdonsĂĄg öröklƑdhetƑsĂ©ge kicsi volt (h2 = 0,08±0,07 and h2 = 0,01±0,04). A tenyĂ©szbikĂĄk elsƑ ellĂ©si Ă©letkor tulajdonsĂĄgra becsĂŒlt tenyĂ©szĂ©rtĂ©ke között meglehetƑsen kicsi kĂŒlönbsĂ©geket talĂĄltak. A fenotĂ­pusos trendszĂĄmĂ­tĂĄs eredmĂ©nyei alapjĂĄn a vizsgĂĄlt idƑszakban a limousin tehenek elsƑ ellĂ©si Ă©letkora Ă©venkĂ©nt 0,33 hĂłnappal csökkent. A genetikai trendszĂĄmĂ­tĂĄs eredmĂ©nyei nem jeleztek Ă©rdemi vĂĄltozĂĄst a vizsgĂĄlt tulajdonsĂĄg ĂĄtlagos tenyĂ©szĂ©rtĂ©kĂ©nek Ă©venkĂ©nti alakulĂĄsĂĄban

    Static properties and spin dynamics of the ferromagnetic spin-1 Bose gas in magnetic field

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    Properties of spin-1 Bose gases with ferromagnetic interaction in the presence of a nonzero magnetic field are studied. The equation of state and thermodynamic quantities are worked out with the help of a mean-field approximation. The phase diagram besides Bose-Einstein condensation contains a first order transition where two values of the magnetization coexist. The dynamics is investigated with the help of the Random Phase Approximation. The soft mode corresponding to the critical point of the magnetic phase transition is found to behave like in conventional theory.Comment: 8 pages and 3 figures included in text, submitted to Physical Review

    HĂșshasznĂș tenyĂ©szbikĂĄk rangsora ivadĂ©kaik teljesĂ­tmĂ©nye alapjĂĄn becsĂŒlt tenyĂ©szĂ©rtĂ©kek alapjĂĄn

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    The objective of this study was to rank Limousin sires by their different breeding values based on the weaning weight of their progeny. 205-day weaning weight record of altogether 18746 purebred and crossbred calves sired by breeding bulls of the mentioned breed were used for the estimation. Calves were belonging to three different groups by their genotype. Three different BLUP animal models were used for the estimation. According the results the direct heritability (h2 d ) estimates of 205-day weight ranged between 0.49 and 0.59, while that of the maternal heritability (h2 m) between 0.24 and 0.45. The estimated breeding value of the given sires differed by the genotype (purebred or crossbred) of their progeny calves and the method of estimation. Also, there were differences in the rank of the sires depending on the genotype of their progeny, as well as the estimation methodsA munka cĂ©lja limousin apĂĄk rangsorĂĄnak a meghatĂĄrozĂĄsa volt ivadĂ©kaik vĂĄlasztĂĄsi sĂșlyadataibĂłl becsĂŒlt tenyĂ©szĂ©rtĂ©kek alapjĂĄn. A szĂĄmĂ­tĂĄsokhoz 18746 fajtatiszta Ă©s keresztezett borjĂș 205 napra korrigĂĄlt vĂĄlasztĂĄsi sĂșlyadatĂĄt hasznĂĄltĂĄk fel. A borjakat genotĂ­pusuk alapjĂĄn hĂĄrom csoportra osztottĂĄk. A szĂĄmĂ­tĂĄsokat hĂĄrom kĂŒlönbözƑ BLUP egyedmodellel vĂ©geztĂ©k. Az eredmĂ©nyek alapjĂĄn a 205 napra korrigĂĄlt vĂĄlasztĂĄsi sĂșly direkt öröklƑdhetƑsĂ©ge (h2 d) 0,49 - 0,59 között vĂĄltozott. Az anyai öröklƑdhetƑsĂ©g (h2 m) 0,24 - 0,45 közötti volt. Az apĂĄk tenyĂ©szĂ©rtĂ©ke között szĂĄmottevƑ kĂŒlönbsĂ©get talĂĄltak annak a fĂŒggvĂ©nyĂ©ben, hogy azt milyen adatbĂĄzison, melyik mĂłdszerrel becsĂŒltĂ©k. Az eredmĂ©nyek alapjĂĄn megĂĄllapĂ­thatĂł, hogy az apĂĄk tenyĂ©szĂ©rtĂ©keik alapjĂĄn felĂĄllĂ­tott rangsora eltĂ©rt egymĂĄstĂłl

    Male gender predisposes to development of endotoxic shock in the rat

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    Objective: After intravenous (i.v.) injection of lipopolysaccharide (LPS) macrophages release nitric oxide (NO) due to the expression of the inducible NO synthase (iNOS). After LPS NO is abundantly produced also in the cardiovascular system and may contribute to the development of hypotension and shock. Since the immune response, the synthesis of NO and the regulation of blood pressure (BP) differ between males and females, in the present study the effect of LPS on BP, renal function, the plasma and urinary concentration of the metabolites of NO as well as the splenic and aortic expression of the iNOS gene were compared between male and female rats. Methods: BP and renal function were measured in anesthetized rats following the i.v. injection of LPS (E. coli, 4 mg/kg). The NOx and NOx (metabolites of NO=NOx) concentration was measured by the Griess reaction. The iNOS gene expression was studied by RT-PCR. Results: Four hours after LPS, BP of males (n=9) was reduced by 63+/-12 mmHg versus 10+/-4 in females (n=7, P<0.005). Aminoguanidine, a selective inhibitor of iNOS, prevented the reduction of BP in males. The plasma concentration of NOx (P-NOx, mu M) was lower in hypotensive males (128+/-20) than in normotensive females (235+/-29, P<0.005). Males also exhibited lower urinary NO, excretion (UNOxV) after LPS (P<0.001 vs, females). Prior castration of males provided protection against hypotension (fall of BP: -4+/-4 mmHg, n=6, P<0.02 versus males) and resulted in higher P-NOx as well as UNOxV (both P<0.001 versus males and not different from females). Prior ovariectomy (n=5) had no influence on the hemodynamic and NOx response to LPS. Male rats displayed enhanced aortic iNOS/beta-actin ratio relative to females after LPS (n=3 in each group, P<0.05). Conclusions: (1) Male gender may sensitize to LPS-induced shock and (2) sensitivity of males to endotoxin is associated with an attenuated, not exaggerated total rate of NO synthesis
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