Journal articles: 'Phage tempéré'

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Nakanishi, Hidetaka, Mineo Asano, and Hideo Yoshida. "Effect of Aging Precipitates on the Bendability of an Al-Mg-Si Alloy." Materials Science Forum 794-796 (June 2014): 572–77. http://dx.doi.org/10.4028/www.scientific.net/msf.794-796.572.

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Al-Mg-Si alloys are usually applied a T4 temper as the plate material for automobile bodies due to the necessity of a high bake hardening property. Many reports about the improvement in the bendability of Al-Mg-Si alloys applied a T4 temper have been published, because they easily crack during the hemming process. On the other hand, Al-Mg-Si alloys applied T6 and T7 tempers are used as the material of wiring plates and heat radiation devices. A high electrical conductivity and good bendability are necessary for these devices. In this study, the effect of the aging conditions on the bendability was investigated. As a result, the bendability at the T6 temper significantly decreased. The bendability under the aging temper, and over the aging temper was better than that at the T6 temper. Samples treated by natural-aging at high temperature before the T6 temper easily cracked during the bending test. It was postulated that the formation of shear bands was significant and the bendability decreased during the bending test under the high density and fine β phase precipitate conditions.

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Zhu, Bao Hong, Yon Gan Zhang, Bai Qing Xiong, Zhi Hui Li, Feng Wang, and Hong Wei Liu. "Effect of Artificial Aging Temper on the Microstructure and Properties of 7B04 Pre-Stretched Thick Plate." Materials Science Forum 519-521 (July 2006): 901–6. http://dx.doi.org/10.4028/www.scientific.net/msf.519-521.901.

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One- and two-step artificial aging had been performed on the 7B04 pre-stretch thick plate, whose nominal composition is similar to 7075 alloy with lower Fe and Si content. The effect of aging temper on the microstructure and properties has been studied. The research results show that T6 temper can improve the mechanical properties of the alloy greatly, yet the alloy have lower electron conductivity which is no more than 19Ms·s-1. When T73 and T74 tempers were performed on the alloy, the mechanical properties of the alloy decreased about 6~10% of the T6 strength while the electron conductivity was improved obviously. With the increasing of the aging temperature, the time that the alloy needs to get peak aging becomes shorter and the mechanical properties at peak aging status are lower. The electron conductivity of the alloy, however, becomes higher with the increasing of aging temperature. The main strengthen phase of 7B04 alloy is also η(MgZn2) phase which is same to other 7xxx series alloys.

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Fan, Xi Gang, Da Ming Jiang, Qing Chang Meng, Heng Ze Xian, and Nian Kui Li. "Influence of Ageing Treatment on Microstructure and Properties of 7150 Alloy." Materials Science Forum 546-549 (May 2007): 849–54. http://dx.doi.org/10.4028/www.scientific.net/msf.546-549.849.

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The microstructure after different ageing treatments and its relation to the mechanical properties and corrosion behavior of 7150 alloy have been investigated. The microstructures were studied by optical microscopy (OM) and transmission electron microscopy (TEM). It was shown that suitable heat treatments led to a combination of high strength and corrosion resistance of the alloy. The yield strength of the alloy is 580MPa in peak aged state, which can be achieved by one step (120 °C/28h) or two step ageing (120°C/6h + 155°C/12h) tempers. The dominant matrix precipitates of the alloy for one step ageing temper are GP zones and η' phase. The alloy after ageing at 120°C for 28h is not susceptible to exfoliation corrosion. On the contrary, the alloy after two step ageing (120°C/6h + 155°C/12h) showed worse exfoliation corrosion resistance. The alloy exhibits high strength and good resistance to the exfoliation corrosion after the ageing treatment of 120°C/6h + 165°C/12h. The dominant precipitates within the grains are η' phase and η phase. The η phase at the grain boundaries plays an important role on the corrosion behaviors. The susceptibility of corrosion is associated with the potential difference between grain and grain boundary, and the characterization of grain boundary precipitates.

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Elesin, Mikhail A., and Gennady I. Berdov. "HYDRATION STUDY OF PORTLAND CEMENT MINERALS IN LIMY-SULFUR TEMPERE." IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENIY KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA 59, no. 5 (July 12, 2018): 54. http://dx.doi.org/10.6060/tcct.20165905.5046.

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The interaction of minerals of the Portland cement (alit, belit, alyumoferrite) was studied with a limy-sulfur tempere. Higher SiO2 content in a liquid phase was established at hydration as well as hydration process acceleration. The strength of cement materials could be increased by 20-40% at application of such tempere with sulfur concentration of 180 g/l.

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Rout, Prasanta Kumar, and K. S. Ghosh. "Aging and Electrochemical Behaviour of 7017 Al-Zn-Mg Alloy of Various Tempers." Materials Science Forum 710 (January 2012): 665–70. http://dx.doi.org/10.4028/www.scientific.net/msf.710.665.

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Artificial aging behaviour of a 7017 Al-Zn-Mg alloy was studied by hardness measurement. The electrochemical behaviour of various alloy tempers, such as under-, peak-, and over-aged, have been evaluated by measuring variation of open circuit potential (OCP) with time and potentiodynamic polarization study in different environments. All the alloy tempers were tested in 3.5 wt. % NaCl solution at neutral (pH 7), at acidic (pH 1) and at alkaline (pH 12) conditions. It has been observed that the OCP values of the alloy tempers shifted toward noble direction with the increase of aging time in 3.5 wt. % NaCl solution. The polarization curves are more or less similar in shape exhibiting only active region in neutral (pH 7) and in acidic (pH 1) conditions, but an active-passive region at alkaline (pH 12) condition. The electrochemical parameters; Ecorr, Icorr, passive potential range (Ep) and passive current (ip), obtained from potentiodyanamic polarization curves for the alloy tempers in acid, neutral and alkaline solution; depend on the alloy tempers and the pH of the solution as well. Attempts have been made to explain the observed electrochemical behaviour of the alloy tempers, which is influenced by the microstructure, presence and distribution of second phase precipitates, accessed by DSC and XRD techniques.

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MacLean, Shannon E., and Lawrence M. Ward. "Temporo-frontal phase synchronization supports hierarchical network for mismatch negativity." Clinical Neurophysiology 125, no. 8 (August 2014): 1604–17. http://dx.doi.org/10.1016/j.clinph.2013.12.109.

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Lafortune, Manuel, Louise Filion, and Bernard Hétu. "Dynamique d’un front forestier sur un talus d’éboulis actif en climat tempéré froid (Gaspésie, Québec)." Géographie physique et Quaternaire 51, no. 1 (October 2, 2002): 67–80. http://dx.doi.org/10.7202/004840ar.

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Résumé Cette recherche a permis de reconstituer, pour les deux derniers siècles, l'évolution de la végétation forestière sur un talus d'éboulis de la vallée de la rivière à Pierre, en Gaspésie. Les données dendroécologiques ont permis de faire ressortir que la limite supérieure de la forêt était plus basse que la limite actuelle vers le milieu du XIXe siècle, que la végétation forestière a connu une phase d'expansion jusque vers le milieu du XXe siècle, bien que certains signes d'instabilité se soient manifestés dès la fin du XIXesiècle. Le front forestier a régressé jusqu'à sa position actuelle après les années 1950. Le taux annuel moyen de sédimentation, calculé par des méthodes dendrogéomorphologiques, a été inférieur à 0,1 cm pendant la deuxième moitié du XIXe siècle pour ensuite atteindre 0,5 cm/an, puis excéder 1,0 cm/an après 1975. L'activité plus importante dans le versant serait associée à une fréquence accrue des coulées de pierres glacées.

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Perlovich, Yuriy, Margarita Isaenkova, Vladimir Fesenko, and Olga Krymskaya. "Texture Evidences of Interaction between Plastic Deformation and Phase Transformations in Zr-Based Alloys." Materials Science Forum 702-703 (December 2011): 283–86. http://dx.doi.org/10.4028/www.scientific.net/msf.702-703.283.

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Abstract. Features of the texture development in Zr-based alloys under compression at tempera-tures of the (α+β)-region of the Zr-Nb phase diagram indicate that the plastic deformation shifts temperatures of phase transformations due to accompanying thermal effects and the decrease of lattice stability, whereas formation of the fine-grained structure by phase transformation promotes activation of the non-crystallographic deformation mechanism of slip by interphase boundaries.

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Yu, Xinxiang, Zhiguo Zhao, Dandan Shi, Xiaoyan Dong, Xianli Shi, Caiqiong Li, Junfeng Zhao, and Han Dai. "Enhancing the Corrosion Resistance and Mechanical Properties of a High-Alloying Al-Zn-Mg-Cu-Zr Alloy by Ce Addition and Aging Treatment." Metals 10, no. 10 (October 1, 2020): 1318. http://dx.doi.org/10.3390/met10101318.

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The corrosion resistance (exfoliation corrosion and inter-granular corrosion) and mechanical properties (strength and hardness) of a high-alloying Al-Zn-Mg-Cu-Zr alloy were improved by the synergistic effect of Ce addition and aging treatment. Ce addition promotes the morphology change of grain boundary precipitates from continuous form to discontinuous form at T6 temper. But the Cu content in grain boundary precipitates became much lower than that in Ce-free alloy, owing to a large amount of Cu being trapped in AlCuCe phase. Hence retrogression and re-aging (RRA) treatment were then adopted. The Cu content in grain boundary precipitates was improved, which can be attributed to the removal of Cu from solid solution during high temperature aging and its subsequent incorporation into grain boundary precipitates. In addition, the size and the distribution discontinuity of the grain boundary precipitates can be further increased and the main intra-grain phases of RRA alloy are still fine η′ phase similar to T6 temper. Therefore, the alloy at RRA temper obtains the optimal corrosion resistance without loss of high strength.

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Ma, Yong Qing, Yu Mei Dai, Yu Fen Liang, and Xiao Jing Zhang. "Temper-Resistance of Cr-W-Mo-V High Carbon Medium Alloy Steel and its Hardness Forecast." Advanced Materials Research 503-504 (April 2012): 591–96. http://dx.doi.org/10.4028/www.scientific.net/amr.503-504.591.

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The temper-resistance temperature of Cr-W-Mo-V high carbon medium alloy steels is in a range at 200°C-300°C. Along with increasing C and alloy contents in particular Cr content of the steels, the temper-resistance is boost up gradually and maximal hardness arrives to 63-64HRC at temperature 200°C-250°C. When budget for quenching matrix composition and undissolved carbides, the actual quenching temperature TH is corresponding to the calculational temperature TC by phase-equilibrium thermodynamics as TH=TC + (1000°C－TC)/6.5, and roughly, the calculational temperature is less 20°C than actual temperature when quenching at 800°C-890°C. The carbides precipitation during tempering is agreement with phase equilibrium thermodynamic calculation incompletely, thereinto (Fe,Cr)3C carbide precipitation is leading at 200°C-250°C.The higher hardness at temper-resistance temperature is corresponding to tempering temperature of remnant austenitic decomposing acutely.The tempering hardness can be estimated on the basis of quenching hardness calculation. The quenching hardness value can be obtained from HC=α（1+β）/(0.00915α+0.00527), in which α is the square root of carbon content in the matrix and β is correction coefficient of solid solution strengthening.

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Rommer, Paulus S., Roland Beisteiner, Kirsten Elwischger, Eduard Auff, and Gerald Wiest. "Neuromagnetic Cortical Activation during Initiation of Optokinetic Nystagmus: An MEG Pilot Study." Audiology and Neurotology 20, no. 3 (2015): 189–94. http://dx.doi.org/10.1159/000375114.

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Purpose: To investigate the spatiotemporal evolution of cortical activation during the initiation of optokinetic nystagmus using magnetoencephalography. Background: Previous imaging studies of optokinetic nystagmus in humans using positron emission tomography and functional magnetic resonance imaging discovered activation of a large set of cortical and subcortical structures during steady-state optokinetic stimulation, but did not provide information on the temporal dynamics of the initial response. Imaging studies have shown that cortical areas responsible for vision in occipital and temporo-occipital areas are involved, i.e. cortical areas control optokinetic stimulation in humans. Magnetoencephalography provides measures that reflect neural ensemble activity in the millisecond time scale, allowing the identification of early cortical components of visuomotor integration. Design/Methods: We studied neuromagnetic cortical responses during the initiation of optokinetic nystagmus in 6 right-handed healthy subjects. Neuromagnetic activity was recorded with a whole-head magnetoencephalograph, consisting of 143 planar gradiometers. Results: The mean (±SD) latency between stimulus onset and initiation of optokinetic nystagmus was 177.7 ± 59 ms. Initiation of optokinetic nystagmus evoked an early component in the primary visual cortex starting at 40-90 ms prior to the onset of the slow phase of nystagmus. Almost simultaneously an overlapping second component occurred bilaterally in the temporo-occipital area (visual motion areas), pronounced in the right hemisphere, starting at 10-60 ms prior to the slow-phase onset. Both components showed long-duration activity lasting for up to 100 ms after slow-phase onset. Conclusions: Our findings suggest that the initiation of optokinetic nystagmus induces early cortical activation in the occipital cortex and almost simultaneously bilaterally in the temporo-occipital cortex. These cortical regions might represent essential areas for the monitoring of retinal slip.

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Villalon-Pooley, Pamela, Camila Hernandez-Veliz, Maria Fernanda Pinto-Chavez, and Pierre Bourdiol. "Gestion orthopédique d’une ankylose de l’ATM chez l’enfant." Revue d'Orthopédie Dento-Faciale 54, no. 4 (November 2020): 407–18. http://dx.doi.org/10.1051/odf/2020041.

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Parmi les fractures cranio-faciales, celles affectant le condyle mandibulaire font partie des fractures les plus souvent rencontrées chez le patient en âge pédiatrique. L’évolution sans traitement peut produire une ankylose temporo-mandibulaire entraînant troubles fonctionnels et asymétrie de la croissance cranio-faciale. Le traitement traditionnellement chirurgical est d’un pronostic généralement réservé. Dans cet article est présenté le cas d’un patient, âgé de quatre ans, atteint d’ankylose fibreuse de l’articulation temporo-mandibulaire gauche, suite probable d’une fracture du col du condyle non-diagnostiquée. La libération fonctionnelle de la fibro-ankylose articulaire a été l’objectif de la première étape thérapeutique. Celle-ci a été suivie, à l’âge de sept ans, d’une distraction articulaire obtenue au moyen de butées occlusales controlatérales disposées côté droit. Ceci a produit un ajustement de la croissance dento-alvéolaire assurant à la fois un rattrapage du déficit de croissance unilatéral de départ et une néoformation condylienne par remodelage de l’articulation temporo-mandibulaire gauche. Quatre années après la mise en route de la phase orthopédique initiale, la fonction articulaire restaurée et l’équilibre facial obtenu restent stables chez ce jeune patient

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Stockert, Anika, Max Wawrzyniak, Julian Klingbeil, Katrin Wrede, Dorothee Kümmerer, Gesa Hartwigsen, Christoph P. Kaller, Cornelius Weiller, and Dorothee Saur. "Dynamics of language reorganization after left temporo-parietal and frontal stroke." Brain 143, no. 3 (February 18, 2020): 844–61. http://dx.doi.org/10.1093/brain/awaa023.

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Abstract The loss and recovery of language functions are still incompletely understood. This longitudinal functional MRI study investigated the neural mechanisms underlying language recovery in patients with post-stroke aphasia putting particular emphasis on the impact of lesion site. To identify patterns of language-related activation, an auditory functional MRI sentence comprehension paradigm was administered to patients with circumscribed lesions of either left frontal (n = 17) or temporo-parietal (n = 17) cortex. Patients were examined repeatedly during the acute (≤1 week, t1), subacute (1–2 weeks, t2) and chronic phase (>6 months, t3) post-stroke; healthy age-matched control subjects (n = 17) were tested once. The separation into two patient groups with circumscribed lesions allowed for a direct comparison of the contributions of distinct lesion-dependent network components to language reorganization between both groups. We hypothesized that activation of left hemisphere spared and perilesional cortex as well as lesion-homologue cortex in the right hemisphere varies between patient groups and across time. In addition, we expected that domain-general networks serving cognitive control independently contribute to language recovery. First, we found a global network disturbance in the acute phase that is characterized by reduced functional MRI language activation including areas distant to the lesion (i.e. diaschisis) and subsequent subacute network reactivation (i.e. resolution of diaschisis). These phenomena were driven by temporo-parietal lesions. Second, we identified a lesion-independent sequential activation pattern with increased activity of perilesional cortex and bilateral domain-general networks in the subacute phase followed by reorganization of left temporal language areas in the chronic phase. Third, we observed involvement of lesion-homologue cortex only in patients with frontal but not temporo-parietal lesions. Fourth, irrespective of lesion location, language reorganization predominantly occurred in pre-existing networks showing comparable activation in healthy controls. Finally, we detected different relationships of performance and activation in language and domain-general networks demonstrating the functional relevance for language recovery. Our findings highlight that the dynamics of language reorganization clearly depend on lesion location and hence open new perspectives for neurobiologically motivated strategies of language rehabilitation, such as individually-tailored targeted application of neuro-stimulation.

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Милинский, А. Ю., С. В. Барышников, Е. В. Стукова, Е. В. Чарная, И. А. Чернечкин, and Н. И. Ускова. "Диэлектрические и тепловые свойства KNO-=SUB=-3-=/SUB=-, внедренного в углеродные нанотрубки." Физика твердого тела 63, no. 6 (2021): 767. http://dx.doi.org/10.21883/ftt.2021.06.50937.018.

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The results of studies of phase transitions of KNO3, embedded in carbon nanotubes, are presented. It is shown that for KNO3 particles in nanotubes, a narrowing of the tempera-ture range of the existence of the ferroelectric phase is observed, similarly to what hap-pens in ferroelectric semiconductors. The results obtained indicate that the external screening from the side of the conducting matrix acts similarly to the screening of spon-taneous polarization in conducting ferroelectrics.

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Golubtsova, Anastasia A., and Nguyen Hoang Vu. "Holographic Wilson Loops in the Confining Backgrounds at Zero Temperature." Communications in Physics 29, no. 3SI (November 4, 2019): 371. http://dx.doi.org/10.15625/0868-3166/29/3si/14248.

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We study Wilson loops in the exact renormalization group ow at zero tempera- ture via the 5d holographic model that reproduces the behavior of the QCD running coupling. Calculating the time-like rectangular Wilson loop we show that the model includes a conning phase at T = 0 in the IR region.

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Stäuble, Harald. "Radiocarbon Dates of the Earliest Neolithic in Central Europe." Radiocarbon 37, no. 2 (1995): 227–37. http://dx.doi.org/10.1017/s003382220003068x.

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I discuss here a series of radiocarbon dates from sites of the earliest phase of the Linearbandkeramik (LBK) culture. The samples were collected during excavations directed by Prof. Jens Lüning (Frankfurt am Main) between 1979 and 1987. The samples were mainly charcoal, including cereals and food remains, but bones and potsherds containing organic temper were also included in the study. Although the results on cereal, bone and food remains were consistent, almost all differed from those measured on charred wood. From a series of dates measured by accelerator mass spectrometry (AMS) on organic temper in potsherds, variable amounts of sample contamination were observed, probably deriving from the natural organic components of the clay used in the ceramic production. By critically evaluating 14C dates, individual activities on the sites were dated as accurately as possible. A chronological framework could then be established for the earliest phase of the LBK culture. The dating results provided information on taphonomic processes.

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Chaturvedi, Mahesh C., and Dao Lun Chen. "Microstructural Characterization and Fatigue Properties of 2195 Al-Li Alloy." Materials Science Forum 519-521 (July 2006): 147–52. http://dx.doi.org/10.4028/www.scientific.net/msf.519-521.147.

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The effect of welding, heat-affected zone (HAZ) simulation, and specimen orientation on the microstructure and fatigue properties of 2195 Al-Li alloy was studied. HAZ simulation and GTA welding with a 4043 filler alloy resulted in a significant change in the microstructure. In the HAZ the primary strengthening phase, T1 (Al2CuLi), in the base alloy in T8 temper was replaced by TB (Al7Cu4Li) phase and voids/microcracks, and the fusion zone (FZ) consisted of T (AlLiSi) phase particles in the matrix, which consisted mainly of the filler alloy. The yield strength and fatigue threshold of the 2195-T8 alloy were observed to be dependent upon the specimen orientation. The HAZ simulation and welding led to a reduction in the tensile properties and fatigue strength. While the post-weld heat treatment resulted in the re-precipitation of T1 phase in the HAZ, but no increase in the fatigue strength was observed due to the presence of microcracks. Fatigue crack initiation was observed to occur at the surface in the base alloy in T8 temper, and at the internal defects after HAZ simulation and welding. Fatigue crack propagation exhibited characteristic striations in the T8 alloy, and brittle cleavage-like feature after HAZ simulation and welding.

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McMahon, Matthew E., Raewyn L. Haines, Patrick J. Steiner, Justine M. Schulte, Sarah E. Fakler, and James T. Burns. "Beta phase distribution in Al-Mg alloys of varying composition and temper." Corrosion Science 169 (June 2020): 108618. http://dx.doi.org/10.1016/j.corsci.2020.108618.

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LI ZAN-LIANG, WANG WEN-SHU, LI WEN-LAI, LIU XIANG, and LI XIAO-CHANG. "SPECTROSCOPIC MEASUREMENT OF ELECTRON TEMPERA-TURE IN CURRENT RISING PHASE ON CT-6B TOKAMAK." Acta Physica Sinica 38, no. 4 (1989): 637. http://dx.doi.org/10.7498/aps.38.637.

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N. Dubnishchev, Yu, V. A. Arbuzov, E. V. Arbuzov, V. S. Berdnikov, O. S. Melekhina, V. V. Sotnikov, and A. A. Shibaev. "Hilbert diagnostics of convective structures and phase transition in super cooled water." International Journal of Engineering & Technology 7, no. 2.23 (April 20, 2018): 295. http://dx.doi.org/10.14419/ijet.v7i2.23.12749.

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The evolution of the crystallization wave front and convective structures in a horizontal layer of supercooled water bounded by tempera- ture-controlled flat surfaces is visualized using methods of Hilbert optics. The phase transition is manifested by the occurrence of a crys- tallization wave and is accompanied by a positive energy release, which, in turn, affects the dynamic distribution of the optical phase density gradient in supercooled water and induces phase perturbations in the probing light field. The results of measurements of the phase velocity and the shape of the crystallization front approximated by Bezier curves are presented. The wave front velocity is obtained using modified time-of-fight method. The phase velocity field is found to exhibit spatio-temporal quasi-periodicity that can be related to the existence of oscillatory phenomena in the crystallization process.

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Xiong, Bai Qing, Kai Wen, Yong An Zhang, Zhi Hui Li, Xi Wu Li, Shu Hui Huang, Li Zhen Yan, Hong Wei Yan, and Hong Wei Liu. "Microstructural Comparison of an Al-8.0Zn-1.8Mg-2.0Cu Alloy with Typical T6 and T76 Tempers." Materials Science Forum 941 (December 2018): 753–58. http://dx.doi.org/10.4028/www.scientific.net/msf.941.753.

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In order to analyze aging behavior of an Al-8.0Zn-1.8Mg-2.0Cu alloy, the microstructure of the alloy subjected to T6 and T76 states are investigated by transmission electron microscopy (TEM) and high-resolution electron microscopy (HREM). Based on the precipitate observations, precipitate size distributions and average precipitate size are extracted from bright-field TEM images projected along 〈110〉Alorientation with the aid of an imaging analysis. The results indicate that the main precipitates are GPI zone, GPII zone and η' phase in the T6 alloy while η' phase and η phase in the T76 alloy. The bright-field TEM observations reveal that the matrix precipitates for the T6 alloy have small size and dispersive distribution while that for the T76 alloy has big size and sparse distribution. Both have discontinuously distributed grain boundary precipitates. Quantitative structural information including precipitate size distribution and average precipitate size has been calculated by an image analysis based on the bright-field TEM images projected along 〈110〉Alorientation. The results show that the T6 alloy has a narrower precipitate size range than the T76 alloy and thus the T6 alloy possesses a smaller average precipitate size than the T76 alloy.

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Lei, Tian, Guan Hong Kong, Xue Ying Cui, Rui Feng, and Sheng Li Li. "The Properties and Structure Stability of Martensite-Bainite Dual Phase Structure in Bearing Steel." Applied Mechanics and Materials 330 (June 2013): 8–11. http://dx.doi.org/10.4028/www.scientific.net/amm.330.8.

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The Martensite-Bainite (M/B) dual phase structure has excellent combined processing properties which can be applied to the bearing steel. Frequently, the service conditions of rolling mill bearings are so harsh that the organization and performance of the bearing materials may change during the using process. The study of structural stability of martensite-bainite dual phase structure is extremely essential. This paper determined the superiority of Martensite-Bainite (M/B) dual phase structure applied to G55SiMoV by contrasting the properties of single martensite and M/B dual phase structure. temper resistance is discussed by testing the change of organization and performance after temper.The results show that the combination property of the M/B dual phase structure are better than the martensitic structure. The G55SiMoV steel with martensite-bainite dual phase structure has a greater temperature range to ensure the tempering stability.

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Fangmeier, Thomas, Markus Knauff, Christian C. Ruff, and Vladimir Sloutsky. "fMRI Evidence for a Three-Stage Model of Deductive Reasoning." Journal of Cognitive Neuroscience 18, no. 3 (March 1, 2006): 320–34. http://dx.doi.org/10.1162/jocn.2006.18.3.320.

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Deductive reasoning is fundamental to science, human culture, and the solution of problems in daily life. It starts with premises and yields a logically necessary conclusion that is not explicit in the premises. Here we investigated the neurocognitive processes underlying logical thinking with event-related functional magnetic resonance imaging. We specifically focused on three temporally separable phases: (1) the premise processing phase, (2) the premise integration phase, and (3) the validation phase in which reasoners decide whether a conclusion logically follows from the premises. We found distinct patterns of cortical activity during these phases, with initial temporo-occipital activation shifting to the prefrontal cortex and then to the parietal cortex during the reasoning process. Activity in these latter regions was specific to reasoning, as it was significantly decreased during matched working memory problems with identical premises and equal working memory load.

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Yuan, Zhi Shan, Zheng Lu, You Hua Xie, Xiu Liang Wu, Sheng Long Dai, and Chang Sheng Liu. "Mechanical Properties of a Novel High-Strength Aluminum-Lithium Alloy." Materials Science Forum 689 (June 2011): 385–89. http://dx.doi.org/10.4028/www.scientific.net/msf.689.385.

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As a heat treatable aluminum alloy to be used in T6 and T8 temper, belongs to Al-Cu-Li system, a novel high-strength aluminum-lithium alloy 2A97 was developed. In order to improve the relationships of strength and ductility and fracture toughness, and to urge the applications in the aeronautical and aerospace industries, the effects of normal heat treatments and thermomechanical heat treatments on the mechanical properties and fracture toughness were investigated by Transmission Electron Microscope(TEM), Scanning Electronic Microscope (SEM), tensile test, and fracture toughness test. The results show that for the alloy aged at 135 °C for 24 h after quenching and 4 percent plastic deformation, its microstructures are strengthened by strain hardening and precipitation hardening, consisting of fine T1phase, θ″/θ′ phase and δ′ phase densely and homogeneously distributed in the matrix. It yields optimum relationship of strength and ductility, fracture toughness, its σ0.2, σband δ5are 454 MPa, 536 MPa, and 11.8%, respectively. It yields 43.5 MPa·m1/2of Kqvalues higher than that of 42.5 MPa·m1/2 in T6 temper. The fracture morphologies of impact tensile samples of fracture toughness test and normal tensile test were observed, indicating the dominance of intergranular failure and subintergranular failure with some dimples and trangranular failure.

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Li, Yu, Yan Bing Zong, and Da Qiang Cang. "Effect of Phase Separation Structure on the Crystallization Property of Blast Furnace Slag." Advanced Materials Research 105-106 (April 2010): 787–90. http://dx.doi.org/10.4028/www.scientific.net/amr.105-106.787.

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Performance of slag glass ceramic largely depends on the phase separation structure formed in heat treatment. In the paper, the crystallization properties and its relation with phase separation structure of blast furnace slag (BFS) are researched. Three water-quenched samples and an air-quenched sample were respectively prepared. After conducting temper experiments and analyzing XRD and DTA results, the following conclusions have been acquired. Two crystallization regions exist in BFS system. In parent glass with phase separation structure, Ca3Mg(SiO4)2 and Ca2MgSi2O7 would form at lower temperature but Ca2Al2Si2O7 would appear at higher temperature than that in parent glass with homogenous structure. The former contributes to the existence of lower polymerized [SiO4] units and more Ca2+ or Mg2+ in Ca-rich phase of phase separation glass, while the later is due to the diffusing hindrance of [AlO4] in diffusing path and interface resistance in phase separation structure.

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Wan, X., J. Liu, and H. Yan. "Phase Correlation based Local Illumination-invariant Method for Multi-Tempro Remote Sensing Image Matching." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XL-3 (August 11, 2014): 365–72. http://dx.doi.org/10.5194/isprsarchives-xl-3-365-2014.

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This paper aims at image matching under significantly different illumination conditions, especially illumination angle changes, without prior knowledge of lighting conditions. We investigated the illumination impact on Phase Correlation (PC) matrix by mathematical derivation and from which, we decomposed PC matrix as the multiplication product of the illumination impact matrix and the translation matrix. Thus the robustness to illumination variation of the widely used Absolute Dirichlet Curve-fitting (AD-CF) algorithm for pixel-wise disparity estimation is proved. Further, an improved PC matching algorithm is proposed: Absolute Dirichlet SVD (AD-SVD), to achieve illumination invariant image alignment. Experiments of matching DEM simulated terrain shading images under very different illumination angles demonstrated that AD-SVD achieved 1/20 pixels accuracy for image alignment and it is nearly entirely invariant to daily and seasonal solar position variation. The AD-CF algorithm was tested for generating disparity map from multi-illumination angle stereo pairs and the results demonstrated high fidelity to the original DEM and the Normalised Correlation Coefficient (NCC) between the two is 0.96.

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Osuch, Piotr, Monika Walkowicz, Tadeusz Knych, and Stanislaw Dymek. "Impact of the Direct Ageing Procedure on the Age Hardening Response of Al-Mg-Si 6101 Alloy." Materials 11, no. 7 (July 19, 2018): 1239. http://dx.doi.org/10.3390/ma11071239.

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Al-Mg-Si alloys are used not only as construction material, but also as a material for electrical conductors. For this application, it is crucial for the alloy to achieve a balance between strength and electrical properties. This is achieved in practice by a combination of strain and precipitation hardening. The current paper focuses on a heat treatment procedure in which the EN AW 6101 alloy is cooled by a flowing air stream from the solutionizing temperature down to the artificial ageing temperature. The proposed procedure, unlike the common heat treatment leading to the T6 temper, allowed for the precipitation of the coarser β” phase with the presence of relatively wide precipitate-free zones. The age hardening response was investigated by Brinell hardness measurements, eddy current testing and microstructural observations using transmission electron microscopy (TEM). The applied heat treatment resulted in slightly lower strength (compared to the T6 temper), but improved electrical performance of the alloy.

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Li, Qing Fen, Xin Fang Cui, Hui Min Zhou, and Ming Liu. "Temper Embrittlement and Fracture Control Method Based on NGS Theory and Grain Refinement Technique." Key Engineering Materials 348-349 (September 2007): 545–48. http://dx.doi.org/10.4028/www.scientific.net/kem.348-349.545.

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Temper embrittlement and fracture control method based on both non-equilibrium grain-boundary segregation (NGS) theory and grain refinement technique are studied in this paper. Grain refinement technique by deformation induced phase transformation in low-alloy steels, 12Gr1MoV and 2.25Gr1MoNb, is investigated. A single-pass hot rolling process by using a Gleeble-1500 system is performed. Experimental results show that steel strength and toughness may be controlled and improved by grain refinement, and that the grain sizes were affected by the deforming temperature, strain reduction, and strain rate. According to the NGS theory, a control method of brittle fracture along grain-boundary is proposed so that some catastrophically brittle fracture failure may be averted. Grain refinement may decrease both the concentration of phosphorus at grain boundaries and the critical time. With the grain refinement technique, the temper embrittlement of steel may be improved, and the critical time may be shortened. The cost of heat treatment for fracture control will therefore be reduced.

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Jarfors, Anders E. W. "Influence of Casting Process Parameters on Surface Roughness in Hot-Chamber Die Casting of AZ91D." Advanced Materials Research 585 (November 2012): 349–53. http://dx.doi.org/10.4028/www.scientific.net/amr.585.349.

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Cast magnesium AZ91D, used for cases, covers and housings, for consumer electronics faces increased requirements on aesthetically pleasing surfaces. The casting conditions have strong effect on as-cast surface roughness for thin-walled castings. This is currently not well understood. In the current study surface roughness was measured parallel and perpendicular to the filling direction and on both sides on straight flat thin speci¬men. The parameters studied were First and Second phase injection speed, Cooling time, and Melt temperature. The Fix and Moving side die tempera¬tures were varied, with the fix side was kept hotter. A D-Optimal experimental design was used resulting in 31 different settings. The re¬sults showed that roughness was decreased by mini¬mizing the temperature difference between the two die halves, increasing cooling time and first phase injection speed. Increasing the second phase injection speed increased roughness.

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Tavormina, G. T. "The temperaments: Its knowledge is a crucial way in early diagnosis of bipolar disorders." European Psychiatry 26, S2 (March 2011): 252. http://dx.doi.org/10.1016/s0924-9338(11)71962-9.

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BackgroundAn observational study of the diagnosis of 300 consecutive new patients in a period of four years led to the main observation of a high percentage of bipolar spectrum diagnosis (4), followed to a new classification of “the bipolar spectrum” (ten sub-types of bipolar spectrum mood).Inside these sub-types also the temperaments have been inserted, even if they are only sub-clinical aspects of the bipolar spectrum (sub-threshold forms).MethodsWith the same method (the diagnostic method was based on an analysis of clinical interviews and personal history of the illness) and with the same aims, others 123 consecutive new patients have been valued for the other subsequential two years; then, all the 423 patients of the six years evaluation have been revalued to put in evidence the presence of their temperaments, emerging from their personal anamnesis.ResultsIt appears clear that significantly more patients within the series appear to have a soft bipolar illness than a major unipolar depression; the depressive episodes are now considered as only one phase of bipolar spectrum. Besides, every patient with bipolar spectrum disorder already presented in their personal history of the illness a sub-clinical evidence of one temperament (hyperthymic temper.: 35%; cyclothymic temper.: 49%; depressive temper.: 16%).ConclusionsThe subthreshold presence of the temperaments in the history of the patients with bipolar spectrum disorders allow us to consider this crucial way for early diagnosis of bipolar spectrum mood disorders.

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Saida, Kazuyoshi, Tomo Ogura, Shotaro Yamashita, and Yusuke Oikawa. "Computer Prediction of Phase Fraction in Multipass Weld of Duplex Stainless Steel - Proposal of Microstructural Improvement Welding Process -." Materials Science Forum 1016 (January 2021): 206–12. http://dx.doi.org/10.4028/www.scientific.net/msf.1016.206.

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Computer simulation of the α/γ phase transformation in multipass weld of duplex stainless steel was made for predicting the distribution of the γ phase fraction in the weld metal (WM) and HAZ. The kinetic equations including rate constants of the dissolution behaviour as well as precipitation behaviour of γ phase were determined by isothermal heat treatment test. Based on the kinetic equations determined, the distribution of the γ phase fraction in multipass weld of duplex stainless steel was calculated applying the incremental method combined with the heat conduction analysis in welding process. The γ phase fraction was reduced in the higher temperature HAZ and WM, however, that in the reheated HAZ and WM was increased and recovered to the base metal level. Microstructural analysis revealed that the calculated results of the γ phase fraction in multipass weld were consistent with experimental ones. Based on the computer prediction, the microstructural improvement welding (“reheat bead welding”) process, with analogous concept to the temper bead welding technique, was newly proposed for recovering the γ phase fraction in weld even in the as-welded situation.

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Klistorner, Alexandr, and Michael Barnett. "Remyelination Trials." Neurology - Neuroimmunology Neuroinflammation 8, no. 6 (August 10, 2021): e1066. http://dx.doi.org/10.1212/nxi.0000000000001066.

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Neuroaxonal loss is believed to underpin the progressive disability that characterizes multiple sclerosis (MS). While focal inflammatory demyelination is a principal cause of acute axonal transection and subsequent axonal degeneration, the gradual attrition of permanently demyelinated axons may also contribute to tissue damage, particularly in the progressive phase of the disease. Therefore, remyelination is considered a putative neuroprotective strategy. In this article, we review the potential pitfalls of remyelination trials, provide a framework for their appropriate design and temper the expectations, at times unrealistic, of researchers, regulators and the pharmaceutical industry.

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Spalletti, Maddalena, Vanni Orzalesi, Riccardo Carrai, Luca Bucciardini, Cesarina Cossu, Maenia Scarpino, Enrico Fainardi, Marinella Marinoni, Antonello Grippo, and Aldo Amantini. "Amplitude Instability of Somatosensory Evoked Potentials as an Indicator of Delayed Cerebral Ischemia in a Case of Subarachnoid Hemorrhage." Clinical EEG and Neuroscience 50, no. 3 (October 3, 2018): 205–9. http://dx.doi.org/10.1177/1550059418804915.

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We describe a 55-year-old male patient with a subarachnoid hemorrhage (SAH) as a result of left middle cerebral artery (MCA) aneurysm rupture, who underwent continuous electroencephalogram (EEG) and somatosensory evoked potential (cEEG-SEP) monitoring that showed an unusual SEP trend pattern. EEG was continuously recorded, and SEPs following stimulation of median nerves were recorded every 50 minutes, with the amplitude and latency of the cortical components automatically trended. An increase in intracranial pressure required a left decompressive craniectomy. cEEG-SEP monitoring was started on day 7, which showed a prolonged (24 hours) instability of SEPs in the left hemisphere. During this phase, left MCA vasospasm was demonstrated by transcranial Doppler (TCD), and computed tomography perfusion (CTP) showed a temporo-parieto-occipital ischemic penumbra. Following intravascular treatment, hypoperfusion and the amplitude of cortical SEPs improved. In our case, a prolonged phase of SEP amplitude instability during vasospasm in SAH correlated with a phase of ischemic penumbra, as demonstrated by CTP. In SAH, SEP instability during continuous monitoring is a pattern of alert that can allow treatments capable of avoiding irreversible neurological deterioration.

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Jacumasso, Sheila Cristina, Luis Otavio Ribas Lima, Juliana Paula Martins, and André Luis Moreira Carvalho. "Influence of Secondary Ageing on Fatigue Crack Propagation of the AA7050 Aluminum Alloy." Advanced Materials Research 891-892 (March 2014): 1816–21. http://dx.doi.org/10.4028/www.scientific.net/amr.891-892.1816.

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The AA7050 aluminum alloy is widely used due to its low specific combined with high strength and toughness obtained from the heat treatment which involves solution treatment and ageing. It produces the mechanism of precipitation hardening of a thin phase and disperses. In this context, the present study to investigated three ageing treatments, their influence on fatigue crack growth. In order to find a better condition of precipitation of η' phase, which may increase resistance to fatigue crack growth of AA7050 aluminum alloy. The T614-65 condition was chosen as an alternative treatment in relation to T7451 and T6 conditions of current use in the industry. The fatigue crack growth rate results have shown that T614-65 fatigue strength were up to 14% higher than the shown for T7451 temper.

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Zuiko, Ivan, Vladislav Kulitckii, and Rustam Kaibyshev. "Effect of Pre-Straining Method on Mechanical Properties of Thermo-Mechanically Processed Al-Cu-Mg Alloy." Defect and Diffusion Forum 385 (July 2018): 364–69. http://dx.doi.org/10.4028/www.scientific.net/ddf.385.364.

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The present study deals with the effect of pre-deformation technique of AA2519 alloy (Al–5.64Cu–0.33Mn–0.23Mg–0.15Zr–0.11Ti–0.09V–0.08Fe–0.01Si (wt. %)) under T8 tempers, on condition that intermediate strains are equal. After undergoing T87 by pre-stretching and peak ageing the alloy demonstrates the yield stress, ultimate tensile strength and elongation to failure of 425.4±2.4 MPa, 475±2.4 MPa, 12.1±0.4%, respectively. The 7% pre-straining by rolling leads to-5% decrease in yield stress, practically the same ultimate tensile strength and-20% decrease in ductility. This effect can be ascribed to more homogeneous distribution of dislocations which act as heterogeneous nucleation sites for the θ′-phase precipitation. In addition to precipitates of the Al–Cu family (θ′′ and θ′), Ω-phase plates on {111}α habit plane was observed. The effect of pre-straining prior to ageing on the precipitation behavior and its relation with mechanical properties of the AA2519 is considered.

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Samokhin, A. G., Ju N. Kozlova, D. V. Korneev, O. S. Taranov, E. A. Fedorov, V. V. Pavlov, V. V. Morozova, and N. V. Tikunova. "Experimental study of the antibacterial activity of the lytic Staphylococcus aureus bacteriophage ph20 and lytic Pseudomonas aeruginosa bacteriophage ph57 during modelling of its impregnation into poly(methylmetacrylate) orthopedic implants (bone cement)." Annals of the Russian academy of medical sciences 73, no. 1 (February 1, 2018): 59–68. http://dx.doi.org/10.15690/vramn905.

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Background: The problem of bacterial colonization of implants used in medical practice continues to be relevant regardless of the material of the implant. Particular attention deserves polymeric implants, which are prepared ex tempore from polymethyl methacrylate, for example - duting orthopedic surgical interventions (so-called "bone cement"). The protection of such implants by antibiotic impregnation is subjected to multiple criticisms, therefore, as an alternative to antibiotics, lytic bacteriophages with a number of unique advantages can be used - however, no experimental studies have been published on the possibility of impregnating bacteriophages into polymethyl methacrylate and their antibacterial activity assessment under such conditions.Aims: to evaluate the possibility of physical placement of bacteriophages in polymethylmethacrylate and to characterize the lytic antibacterial effect of two different strains of bacteriophages when impregnated into polymer carrier ex tempore during the polymerization process in in vitro model.Materials and methods: First stage - Atomic force microscopy (AFM) of polymethyl methacrylate samples for medical purposes was used to determine the presence and size of caverns in polymethyl methacrylate after completion of its polymerization at various reaction temperatures (+6…+25°C and +18…+50°C).The second stage was performed in vitro and included an impregnation of two different bacteriophage strains (phage ph20 active against S. aureus and ph57 active against Ps. aeruginosa) into polymethyl methacrylate during the polymerization process, followed by determination of their antibacterial activity.Results: ACM showed the possibility of bacteriophages placement in the cavities of polymethyl methacrylate - the median of the section and the depth of cavities on the outer surface of the polymer sample polymerized at +18…+50°C were 100.0 and 40.0 nm, respectively, and on the surface of the transverse cleavage of the sample - 120.0 and 100.0 nm, respectively, which statistically did not differ from the geometric dimensions of the caverns of the sample polymerized at a temperature of +6…+25°C.The study of antibacterial activity showed that the ph20 bacteriophage impregnated in polymethyl methacrylate at +6…+25°C lost its effective titer within the first six days after the start of the experiment, while the phage ph57 retained an effective titer for at least 13 days.Conclusion: the study confirmed the possibility of bacteriophages impregnation into medical grade polymethyl methacrylate, maintaining the effective titer of the bacteriophage during phage emission into the external environment, which opens the way for the possible application of this method of bacteriophage delivery in clinical practice. It is also assumed that certain bacteriophages are susceptible to aggressive influences from the chemical components of "bone cement" and / or polymerization reaction products, which requires strict selection of bacteriophage strains that could be suitable for this method of delivery.

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Sambugaro, Lucas, Isabela Toledo Teixeira da Silveira, Ercio Junior Montenegro de Andrade, Marina de Almeida Barbosa Mello, Ana Carolina Bonetti Valente, and Renato Yassutaka Faria Yaedú. "Implications of Distraction Osteogenesis in Ankylosis of Temporomandibular Joint." Journal of Health Sciences 22, no. 4 (December 21, 2020): 229–36. http://dx.doi.org/10.17921/2447-8938.2020v22n4p229-236.

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AbstractStudies with children and adult patients submitted to mandibular distraction osteogenesis surgery were analyzed, whose complication was ankylosis of the temporomandibular joint. In this study, the objective was to carry out a narrative review of the literature, seeking the prevalence of this complication after distraction osteogenesis. The literature review was carried out in the electronic databases, PubMed and Scopus, using mesh terms and their respective entry terms. The screening process consisted of two phases: Phase I - Select by titles and abstracts; Phase II - Complete reading article based on selected articles from phase I. It was observed after the data tabulation a lack of scientific evidence regarding this complication after distraction osteogenesis; as well as a very large variability in the case report studies or case series since there are no clinical trials on this subject. Thus, it can be concluded that there are few studies to state the relationship between ankylosis of the temporomandibular joint after distraction osteogenesis, requiring further clinical trial studies on the subject. Keywords: Temporomandibular Joint Dysfunction Syndrome. Temporomandibular Joint Disorders. Osteogenesis. Distraction. Callotasis; Bone Formation ResumoForam analisados estudos com pacientes crianças e adultos submetidos a cirurgia de distração osteogênica mandibular que tiveram como complicação a anquilose da articulação temporo-mandibular. Neste estudo o objetivo foi realizar uma revisão narrativa da literatura buscando a prevalência desta complicação após a distração osteogênica. A revisão de literatura foi realizada nas bases de dados eletrônicas, PubMed e Scopus, utilizando mesh terms e seus respectivos entry terms. O processo de triagem consistiu em duas fases: Fase I - Selecionar por títulos e resumos; Fase II- Artigo completo de leitura baseado em artigos selecionados da fase I. Observou-se após a tabulação dos dados a falta de evidência científica com relação a esta complicação após a distração osteogênica; bem como uma variabilidade muito grande nos trabalhos de relato de caso ou série de casos uma vez que não existem ensaios clínicos referente a este assunto. Desta forma pode-se concluir que há poucos estudos para afirmarmos a relação entre a anquilose da articulação temporo-mandibular após a distração osteogênica, sendo necessários mais estudos de ensaio clínico sobre o tema. Palavras-chave: Síndrome da Disfunção da Articulação Temporomandibular. Transtornos da Articulação Temporomandibular. Calotasia. Formação Óssea.

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Jianqi Wang, Hongbin Tu, and QinJun Jiang. "An XPS Investigation of Thermal Degradation and Charring Processes for Polymers in the Condensed Phase. I." Journal of Fire Sciences 13, no. 4 (July 1995): 261–80. http://dx.doi.org/10.1177/073490419501300402.

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Crosslinking and charring in the condensed phase of polymers during heating, processing, and/or burning are of central importance in their flame retardance and smoke suppression and in formulating polymeric compos ites. Combining with thermal analysis techniques (TGA, DSC), ethylene-vinyl acetate (EVA) copolymers and polyethylenes (HDPE, LDPE) with/without inor ganic phosphorus-containing additives, were selected as model systems for XPS studies of the charring process. A new parameter, Tgr, the transition tempera ture from mesophase to graphitic structure (graphite-like structure, GLS) of the char has been well-defined and determined by combination of core levels and valence bands in XPS. The reason for Tgr to be selected as a likely supplemen tary parameter for characterizing polymer charring in condensed phase is two fold : 1) a clear-cut phase transition; 2) at which temperature a highly cross linked network results. A special emphasis in the paper has been given to the roles of the oxygen atoms either introduced from an adventitious atmosphere or inherent Ac group itself. Along this line some features in both thermal degradation and flame retardance of polymers have been rationalized in terms of transition temperature Tgr.

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Chaussé, Christine, Nicole Limondin-Lozouet, Serge Occhietti, Pierre Voinchet, and Jean-Christophe Bacon. "La Nappe alluviale de Soucy-Les-Grandes-Pièces (Yonne, France) : reconstitution pluridisciplinaire du fonctionnement d’un cours d’eau du Pléistocène moyen." Géographie physique et Quaternaire 54, no. 2 (October 2, 2002): 187–208. http://dx.doi.org/10.7202/004779ar.

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Résumé La Nappe alluviale de Soucy (Yonne, France) a livré six gisements du Paléolithique inférieur. Sa mise en place peut être rapportée, d'après l'aminochronologie et les datations RPE sur quartz, aux stades isotopiques 10 et 9. Le rang interglaciaire des formations fluviatiles supérieures fines est souligné par les malacofaunes qui révèlent un milieu tempéré continental. Une reconstitution des différentes étapes de la construction de la plaine alluviale est proposée à partir de la morphologie des dépôts, l'image C-M, l'analyse des traits pédosédimentaires en lames minces et l'étude des malacofaunes. Le remblaiement s'organise à partir de plusieurs chenaux dont les fonctionnements sont distincts dans le temps et l'espace. Le chenal A, le plus ancien, est bordé en rive occidentale par un banc de convexité. Au cours d'une étape ultérieure, un lit fluvial à chenaux multiples, parcouru par des écoulements énergiques mais intermittents, s'installe sur la rive orientale du chenal A. L'incision du chenal B se produit à l'issue de la migration du cours d'eau vers l'est. Le milieu est légèrement boisé. Le développement d'un sol alluvial grisâtre marque ensuite une phase de stabilisation, qui s'accompagne de la régression des malacofaunes forestières. L'étape suivante est caractérisée par des dépôts de plaine d'inondation qui recouvrent l'ensemble de la plaine. Le développement de mollusques xérophiles et la puissante aggradation sédimentaire indiquent l'ouverture du milieu qui pourrait correspondre à la dégradation des conditions climatiques dans le cadre de la fin d'un interglaciaire.

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Handayani, Nita, Freddy Haryanto, Siti Nurul Khotimah, Idam Arif, and Warsito Purwo Taruno. "Coherence and phase synchrony analyses of EEG signals in Mild Cognitive Impairment (MCI): A study of functional brain connectivity." Polish Journal of Medical Physics and Engineering 24, no. 1 (March 1, 2018): 1–9. http://dx.doi.org/10.2478/pjmpe-2018-0001.

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Abstract This paper presents an EEG study for coherence and phase synchrony in mild cognitive impairment (MCI) subjects. MCI is characterized by cognitive decline, which is an early stage of Alzheimer’s disease (AD). AD is a neurodegenerative disorder with symptoms such as memory loss and cognitive impairment. EEG coherence is a statistical measure of correlation between signals from electrodes spatially separated on the scalp. The magnitude of phase synchrony is expressed in the phase locking value (PLV), a statistical measure of neuronal connectivity in the human brain. Brain signals were recorded using an Emotiv Epoc 14-channel wireless EEG at a sampling frequency of 128 Hz. In this study, we used 22 elderly subjects consisted of 10 MCI subjects and 12 healthy subjects as control group. The coherence between each electrode pair was measured for all frequency bands (delta, theta, alpha and beta). In the MCI subjects, the value of coherence and phase synchrony was generally lower than in the healthy subjects especially in the beta frequency. A decline of intrahemisphere coherence in the MCI subjects occurred in the left temporo-parietal-occipital region. The pattern of decline in MCI coherence is associated with decreased cholinergic connectivity along the path that connects the temporal, occipital, and parietal areas of the brain to the frontal area of the brain. EEG coherence and phase synchrony are able to distinguish persons who suffer AD in the early stages from healthy elderly subjects.

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Xie, Hua, Iliana I. Karipidis, Amber Howell, Meredith Schreier, Kristen E. Sheau, Mai K. Manchanda, Rafi Ayub, et al. "Finding the neural correlates of collaboration using a three-person fMRI hyperscanning paradigm." Proceedings of the National Academy of Sciences 117, no. 37 (August 25, 2020): 23066–72. http://dx.doi.org/10.1073/pnas.1917407117.

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Humans have an extraordinary ability to interact and cooperate with others. Despite the social and evolutionary significance of collaboration, research on finding its neural correlates has been limited partly due to restrictions on the simultaneous neuroimaging of more than one participant (also known as hyperscanning). Several studies have used dyadic fMRI hyperscanning to examine the interaction between two participants. However, to our knowledge, no study to date has aimed at revealing the neural correlates of social interactions using a three-person (or triadic) fMRI hyperscanning paradigm. Here, we simultaneously measured the blood-oxygenation level-dependent signal from 12 triads (n = 36 participants), while they engaged in a collaborative drawing task based on the social game of Pictionary. General linear model analysis revealed increased activation in the brain regions previously linked with the theory of mind during the collaborative phase compared to the independent phase of the task. Furthermore, using intersubject correlation analysis, we revealed increased synchronization of the right temporo‐parietal junction (R TPJ) during the collaborative phase. The increased synchrony in the R TPJ was observed to be positively associated with the overall team performance on the task. In sum, our paradigm revealed a vital role of the R TPJ among other theory-of-mind regions during a triadic collaborative drawing task.

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Ribas Lima, Luis Otavio, Sheila Cristina Jacumasso, Cassius Olivio Figueiredo Terra Ruchert, Juliana Paula Martins, and André Luis Moreira Carvalho. "Study of the Effects of Two-Step Ageing Heat Treatment on Fatigue Crack Growth on an AA7050 Aluminum Alloy." Advanced Materials Research 891-892 (March 2014): 1111–16. http://dx.doi.org/10.4028/www.scientific.net/amr.891-892.1111.

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Aluminum alloys are the first chosen materials for aircraft structures since 1930 due to their high ratio between properties and density. Currently, aircraft industries use Al-Zn-Mg-Cu alloys, with T7451 temper, which it shows high strength, fatigue and corrosion resistance. The improvements properties are result from the η’ phase formation, MgZn2. The aim the present work is to propose an alternative route for ageing heat treatment at one AA7050 aluminum alloy, the manner which the formation of η’ phase particles at lower temperatures and longer periods of treatment is obtained. According to the literature, ageing treatments at low temperatures and longer periods optimize the usage of the solution atoms, favoring the growth and nucleation particles. As a result, there is an increase in the density of the particle improving the alloy properties. These improvements show a decrease up to 13% in the crack propagation rate for moderate ΔK levels, keeping the same levels of Vickers hardness but with decay of 12% of ultimate tensile strength.

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Gebril, Mohamed A., M. S. Aldlemey, and Abdessalam F. Kablan. "Effect of Tempering on Mechanical Properties and Corrosion Rate of Medium and High Carbon Steel." Advanced Materials Research 685 (April 2013): 81–85. http://dx.doi.org/10.4028/www.scientific.net/amr.685.81.

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The tempering process of medium and high carbon steel using quenching in water as quenching medium with different tempering temperatures has been investigated. The samples were quenched to room temperature in water. The mechanical properties and corrosion rate of the quench and tempering samples were measured. The result shows that hardness value of the medium and high carbon steel increased due to formation of martensite structure which is very strong phase but it is normally very brittle, so it is necessary to modify the mechanical properties and relieve internal stresses by heat treatment in the range 100-700°C. The experimental results revealed that mechanical properties of selective alloy were significantly changed by temper treatment. By increasing the tempering temperature, hardness and ultimate tensile strength are gradually decreased and ductility was improved. Moreover, the corrosion rate has been studied and shown within multiple phase structure corrosion rate increased more than martensite structure even its stressed structure.

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Kishchenko, I. T. "DYNAMICS OF THE CONTENT OF NITROGENOUS SUBSTANCES AND LIPIDS IN THE NEEDLES OF INTRODUCED SPECIES PICEA А. DIETR. IN THE TAIGA ZONE (KARELIA)." Вестник Пермского университета. Серия «Биология»=Bulletin of Perm University. Biology, no. 1 (2020): 4–12. http://dx.doi.org/10.17072/1994-9952-2020-1-4-12.

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Studies were conducted in the Botanical Garden of Petrozavodsk State University, located in the taiga zone. The objects were 1 aboriginal (Рicea fennica (Regel) Кom.) аnd 5 introduced (P. pungens Engelm. f. glauca Regel and f. viridis Regel, P. obovata Ledeb., P. glauca (Mill.) Britt., P. omorica (Pane) Purk., P. mariana Britt.). It is established that in the process of adaptation of introduced species Picea to low winter tempera-tures most of the involved proteins. Their number increases significantly during the transition from the period of active shoot growth to a period of deep rest have all studied species of Picea. The accumulation of proteins causes a decrease in the level of total free amino acids of most types of exotic species, while the local form of the amino acid content is maintained at a high level. In the needles of most of the studied species of Picea to the period of deep rest, the fraction of glutamic acid and albanina and increases the proportion of arginine and ethanolamine in the total amount of amino acids. The increase in the content of total lipids and phospholipids in the needles during the transition to a period of deep rest less significant than proteins. In the needles of na-tive species in comparison with the needles of exotic species total lipids actively used in the phase of inten-sive growth of shoots. Despite some differences, the introduced species Picea adapted to endure low tempera-tures using the same biochemical mechanisms as a local view. This indicates successful adaptation of the studied introduced species Picea to new conditions of existence.

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Hur, Bo Young, Sang Hun Cho, and Sang Youl Kim. "Effect of Skin Pass Mill Elongation on Characteristics of Surface Friction and Formability." Materials Science Forum 486-487 (June 2005): 261–64. http://dx.doi.org/10.4028/www.scientific.net/msf.486-487.261.

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Coated sheet steels have been increasingly used in automotive industry for improving corrosion resistance. When GA outer plates processed the interfacing of the coating film and the metal matrix causes surface irregularities in the surface state of the sheet metal. Consequently, research to determine each phase composite’s friction coefficient is on-going. Investigating the effects that cause surface roughness, change and mechanical properties of outer automobile plates through temper rolling skin pass mill elongation is essential. Researching surface roughness in relation to surface friction properties requires the determination of a surface friction coefficient. This research demonstrates that there is a complex effect between the lubricant membrane and surface roughness when processing GA plates. Consequently, the strength of the lubricant membrane strongly influences the friction coefficient

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Kim, Bong Hwan, Su Kwon Jung, Young Ok Yoon, Hyun Kyu Lim, and Shae K. Kim. "Effect of Mg Content on Age Hardening of an Extruded Al-Si-Mg-Mn Alloy." Advanced Materials Research 630 (December 2012): 54–58. http://dx.doi.org/10.4028/www.scientific.net/amr.630.54.

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The main task of this study was to investigate the effect of Mg content on hardness of extruded Al-Si-Mg-Mn alloy after solution and artificial ageing heat-treatments. The Al-Si-Mg-Mn alloys with the variation of Mg content were fabricated through casting, homogenization and extrusion processes. The extruded samples were heat-treated – T6 temper. Thermal analysis with metallurgical examination was performed in order to optimize the condition of solution heat-treatment. Then, microstructure change was discussed by using optical microscopy and SEM-EDS. And the corresponding Vickers hardness was measured as a function of ageing time. It was found that the Vickers hardness slightly increased due to improved ageing efficiency and increased hard phase as the Mg content increased.

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Seidman, David N., John D. Rittner, and Dmitry Udler. "Monte Carlo Simulation of Solute-Atom Segregation at Grain Boundaries In Single-Phase Binary Face-Centered Cubic Alloys." Microscopy and Microanalysis 4, S2 (July 1998): 764–65. http://dx.doi.org/10.1017/s1431927600023941.

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Solute-atom segregation to grain boundaries has been of interest since the 1930's when it was realized that some steels were susceptible to failure by intergranular fracture when certain impurities were present. Segregation of impurities or intentionally added alloying elements at grain boundaries can greatly affect various grain boundary properties, which in turn affect numerous macroscopic properties. Materials phenomena that have been linked to grain boundary segregation include temper brittleness, fatigue strength, adhesion, precipitation, diffusional creep, intergranular corrosion, and grain boundary diffusivity. Although grain boundary segregation has been extensively studied for many years, the effects of different grain boundary structures on segregation was generally not considered. It has been established both experimentally and theoretically that the level of segregation varies from grain boundary to grain boundary in the same alloy, but there is little direct information on how grain boundary structure influences segregation.

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Wang, Jiang Bo, Zai Yan Shang, Zhi Shan Yuan, Jin Zhou, Zhao Wei Feng, Wei Dong Miao, and Ming Zhu. "Study on the Mechanical Property and Microstructure of Surgical Implanted Ti-6Al-7Nb Titanium Alloy." Advanced Materials Research 535-537 (June 2012): 945–49. http://dx.doi.org/10.4028/www.scientific.net/amr.535-537.945.

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Ti-6Al-7Nb titanium alloy is attractive to medical device industry for orthopedic applications, such as total hip replacement systems, fracture fixation plates, intermedullary rods and nails, spinal devices, screws, and wires. Substituting Niobium for Vanadium as the beta stabilizing element, Ti-6Al-7Nb titanium alloy shows higher biocompatability than Ti-6Al-4V titanium alloy. The present research is designed to investigate the influence of annealling temper on the mechanical properties and microstructures of Ti-6Al-7Nb titanium alloy, by optical microscopic (OM) and scanning electron microscopic (SEM), and tensile test. The results show that the microstructures after recrystalization heat treatment comprise a mount of equiaxed α grains in the matrix of equiaxed β phase with α (hcp)/ β (bcc) platelets. The microstructures with partial recrystalization α phase possess better mechanical properties which conform to the ASTM F 1295 standard and ISO 5832-11 standard. Compared with Ti-6Al-4V titanium alloy and CP titanium alloy, Ti-6Al-7Nb titanium alloy is suitable to be used as implanted biomaterial devices to replace ill-functioning or missing tissues or organs.

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Sommer, M., S. Hoja, M. Steinbacher, and R. Fechte-Heinen. "Investigation of Compound Layer Structures after Nitriding and Nitrocarburizing of Quenched and Tempered Steels." HTM Journal of Heat Treatment and Materials 76, no. 3 (June 1, 2021): 219–36. http://dx.doi.org/10.1515/htm-2021-0005.

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Abstract A compound layer is formed by ingress of nitrogen from an external nitrogen source into the surface layer and the formation of nitrides when the solubility of nitrogen in the bulk material is exceeded. In the surface layer, where the nitrogen concentration is at its maximum level, the nitrides form a closed layer. The compound layer continues to contain alloy nitrides which have formed from the carbides and other precipitates from the bulk material. The properties of the compound layer have a decisive influence on the wear and fatigue behavior of the loaded surfaces. The current investigations deal with the extensive characterization of compound layers that have been produced in heat treatment processes with the aim of producing stress-resistant nitriding layers. The commonly used nitriding and quench and temper (Q&T) steels 31CrMoV9 and 42CrMo4 served as examination material. The structure of the compound layers was varied within the nitriding trials regarding the phase composition, porosity and layer thicknesses. The phase composition of the compound layers was determined by special etching, scanning electron microscopy (SEM), X-ray diffraction and GDOES.

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Saarinen, Timo, Jan Kujala, Hannu Laaksonen, Antti Jalava, and Riitta Salmelin. "Task-Modulated Corticocortical Synchrony in the Cognitive-Motor Network Supporting Handwriting." Cerebral Cortex 30, no. 3 (October 16, 2019): 1871–86. http://dx.doi.org/10.1093/cercor/bhz210.

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Abstract Both motor and cognitive aspects of behavior depend on dynamic, accurately timed neural processes in large-scale brain networks. Here, we studied synchronous interplay between cortical regions during production of cognitive-motor sequences in humans. Specifically, variants of handwriting that differed in motor variability, linguistic content, and memorization of movement cues were contrasted to unveil functional sensitivity of corticocortical connections. Data-driven magnetoencephalography mapping (n = 10) uncovered modulation of mostly left-hemispheric corticocortical interactions, as quantified by relative changes in phase synchronization. At low frequencies (~2–13 Hz), enhanced frontoparietal synchrony was related to regular handwriting, whereas premotor cortical regions synchronized for simple loop production and temporo-occipital areas for a writing task substituting normal script with loop patterns. At the beta-to-gamma band (~13–45 Hz), enhanced synchrony was observed for regular handwriting in the central and frontoparietal regions, including connections between the sensorimotor and supplementary motor cortices and between the parietal and dorsal premotor/precentral cortices. Interpreted within a modular framework, these modulations of synchrony mainly highlighted interactions of the putative pericentral subsystem of hand coordination and the frontoparietal subsystem mediating working memory operations. As part of cortical dynamics, interregional phase synchrony varies depending on task demands in production of cognitive-motor sequences.

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Journal articles on the topic 'Phage tempéré'

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