scholarly journals Phase Formation Sequence In The Pd-Gaas System

1985 ◽  
Vol 54 ◽  
Author(s):  
T. Sands ◽  
V. G. Keramidas ◽  
A. J. Yu ◽  
K. M. Yu ◽  
R. Gronsky ◽  
...  
Keyword(s):  
Phase I ◽  
Phase Formation ◽  
Ternary Phase ◽  
Annealing Temperature ◽  
Large Angle ◽  
Second Phase ◽  
X Rays ◽  
Morphological Aspects ◽  
Transmission Electron ◽  
Phase Phase

ABSTRACTThe morphological aspects of ternary phase formation during the Pd-GaAs reaction have been studied by application of transmission electron microscopy (TEM) and Rutherford backscattering (RBS) techniques. The TEM images show that the first product phase, “phase I”, forms during deposition of Pd onto (100) GaAs and exhibits the preferred orientation [0001]I ∼ // [011]GaAs. In the presence of unreacted Pd, the second phase, “phase II”, nucleates at large-angle grain boundaries in the phase I film as the annealing temperature increases above ∼ 250°C Energy dispersive analysis of x-rays and RBS suggest that both phases I and II have nominal compositions in the range of Pd3GaAs to Pd4GaAs.

In-Situ Study of Ti/TiN Stability under Nitrogen Anneal

1999 ◽  
Vol 564 ◽  
Author(s):  
P. W. DeHaven ◽  
K. P. Rodbell ◽  
L. Gignac
Keyword(s):  
Annealing Temperature ◽  
Time Range ◽  
Second Phase ◽  
Transformation Rate ◽  
Transformation Mechanism ◽  
Second Stage ◽  
Transmission Electron ◽  
Reaction Proceeds ◽  
Two Stages

AbstractThe effectiveness of a TiN capping layer to prevent the conversion of α-titantium to titanium nitride when annealed in a nitrogen ambient has been studied over the temperature range 300–700°C using in-situ high temperature diffraction and transmission electron microscopy. Over the time range of interest (four hours), no evidence of Ti reaction was observed at 300°C. At 450°C. nitrogen was found to diffuse into the Ti to form a Ti(N) solid solution. Above 500°C the titanium is transformed to a second phase: however this reaction follows two different kinetic paths, depending on the annealing temperature. Below 600°C. the reaction proceeds in two stages, with the first stage consisting of Ti(N) formation, and the second stage consisting of the conversion of the Ti(N) with a transformation mechanism characteristic of short range diffusion (grain edge nucleation). Above 600°C, a simple linear transformation rate is observed.

scholarly journals Involvement of NO in Antinociception of NSAIDS in Murine Formalin Hind Paw Assay

Drug Research ◽  
2020 ◽  
Vol 70 (04) ◽  
pp. 145-150 ◽  
Author(s):  
Viviana Noriega ◽  
Hugo F. Miranda ◽  
Juan Carlos Prieto ◽  
Ramón Sotomayor-Zárate ◽  
Fernando Sierralta
Keyword(s):  
Phase I ◽  
Phase Ii ◽  
Dose Response ◽  
Rank Order ◽  
Linear Regression Analysis ◽  
Second Phase ◽  
Response Curves ◽  
Before And After ◽  
Two Phases ◽  
Phase Phase

AbstractThere are different animal models to evaluate pain among them the formalin hind paw assay which is widely used since some of its events appear to be similar to the clinical pain of humans. The assay in which a dilute solution of formalin is injected into the dorsal hindpaw of a murine produces two ‘phases’ of pain behavior separated by a inactive period. The early phase (Phase I) is probably due to direct activation of nociceptors and the second phase (Phase II) is due to ongoing inflammatory input and central sensitization. Mice were used to determine the potency antinociceptive of piroxicam (1,3,10,and 30 mg/kg), parecoxib (0.3, 1,3,10 and 30 mg/kg), dexketoprofen (3,10,30 and 100 mg/kg) and ketoprofen (3,10,30 and 100 mg/kg). Dose-response for each NSAIDs were created before and after 5 mg/kg of L-NAME i.p. or 5 mg/kg i.p. of 7-nitroindazole. A least-squares linear regression analysis of the log dose–response curves allowed the calculation of the dose that produced 50% of antinociception (ED50) for each drug. The ED50 demonstrated the following rank order of potency, in the phase I: piroxicam > dexketoprofen > ketoprofen > parecoxib and in the phase II: piroxicam > ketoprofen > parecoxib > dexketoprofen. Pretreatment of the mice with L-NAME or 7-nitroindazol induced a significant increase of the analgesic power of the NSAIDs, with a significant reduction of the ED50. It is suggested that NO may be involved in both phases of the trial, which means that nitric oxide regulates the bioactivity of NSAIDs.

GERDA results and the future perspectives for the neutrinoless double beta decay search using 76Ge

2018 ◽  
Vol 33 (09) ◽  
pp. 1843004 ◽  
Author(s):  
◽  
M. Agostini ◽  
A. M. Bakalyarov ◽  
M. Balata ◽  
I. Barabanov ◽  
...  
Keyword(s):  
Phase I ◽  
Beta Decay ◽  
Phase Ii ◽  
Half Life ◽  
Liquid Argon ◽  
Neutrinoless Double Beta Decay ◽  
Double Beta Decay ◽  
Second Phase ◽  
Inverted Hierarchy ◽  
Phase Phase

The GERmanium Detector Array (GERDA) is a low background experiment at the Laboratori Nazionali del Gran Sasso (LNGS) of INFN designed to search for the rare neutrinoless double beta decay ([Formula: see text]) of [Formula: see text]Ge. In the first phase (Phase I) of the experiment, high purity germanium diodes were operated in a “bare” mode and immersed in liquid argon. The overall background level of [Formula: see text] was a factor of ten better than those of its predecessors. No signal was found and a lower limit was set on the half-life for the [Formula: see text] decay of [Formula: see text]Ge [Formula: see text] yr (90% CL), while the corresponding median sensitivity was [Formula: see text] yr (90% CL). A second phase (Phase II) started at the end of 2015 after a major upgrade. Thanks to the increased detector mass and performance of the enriched germanium diodes and due to the introduction of liquid argon instrumentation techniques, it was possible to reduce the background down to [Formula: see text]. After analyzing 23.2 kg[Formula: see text]⋅[Formula: see text]yr of these new data no signal was seen. Combining these with the data from Phase I a stronger half-life limit of the [Formula: see text]Ge [Formula: see text] decay was obtained: [Formula: see text] yr (90% CL), reaching a sensitivity of [Formula: see text] yr (90% CL). Phase II will continue for the collection of an exposure of 100 kg[Formula: see text]yr. If no signal is found by then the GERDA sensitivity will have reached [Formula: see text] yr for setting a 90% CL. limit. After the end of GERDA Phase II, the flagship experiment for the search of [Formula: see text] decay of [Formula: see text]Ge will be LEGEND. LEGEND experiment is foreseen to deploy up to 1-ton of [Formula: see text]Ge. After ten years of data taking, it will reach a sensitivity beyond 10[Formula: see text] yr, and hence fully cover the inverted hierarchy region.

The Effect of Annealing Temperature on the Properties and Second-Phase Particles of 0.4mm Galvanized Ti-IF Steel

2013 ◽  
Vol 442 ◽  
pp. 58-63
Author(s):  
Feng Li ◽  
Jia Shun Lv ◽  
Hong Gang Yang ◽  
Fang Zhou ◽  
Leng Zhang ◽  
...  
Keyword(s):  
Annealing Temperature ◽  
Second Phase ◽  
Transmission Electron Microscopy Analysis ◽  
Maximum Value ◽  
Transmission Electron ◽  
Second Phase Particles ◽  
Electron Microscopy Analysis ◽  
Microscopy Analysis ◽  
Annealing Experiments ◽  
Tension Strength

A series of simulated continuum annealing experiments were done on 0.4mm Ti-IF by Gleeble-3800 thermal simulation machine at 700, 730, 760, 790, 820 and 850 degree. The optical microstructures of the specimens were characterized. Transmission electron microscopy analysis was carried out to investigate the second phase particles shape, size and distribution. The mechanical properties of the specimens were measured. The results showed that the yield strength and the tension strength of the steel decreased when the annealing temperature increased, the elongation increased when the annealing temperature increased, expect a maximum elongation value at 760 degree. Based on the microstructure and the second phase, the reason why there was a maximum value was discussed.

Some Empirical Findings on Nations and their Behavior

1969 ◽  
Vol 21 (2) ◽  
pp. 226-241 ◽  
Author(s):  
R. J. Rummel
Keyword(s):  
Mathematical Model ◽  
Factor Analysis ◽  
Phase I ◽  
Quantitative Research ◽  
Second Phase ◽  
National Data ◽  
Dimensions Of Variation ◽  
Phase Phase ◽  
Cross National

With The growing academic and governmental interest in quantitative research on nations, it is becoming increasingly important to separate substantive findings from the technical arcana in which they are embedded. In recognition of this need, this report extracts and consolidates the major results of the Dimensionality of Nations (DON) project.The Don project (6) has been in existence since 1962 and is now in its second phase. Phase I of DON defined the major dimensions of variation among all nations for the mid-1950's and the grouping of nations on these dimensions. During this phase much of the methodological underbrush surrounding the use on cross-national data of its major mathematical model—factor analysis—was cleared away, and some measure of control was developed over problems of error and noncomparability in the data.

Metallurgical Reactions in Au/Ge/Au Contact to Gallium Arsenide

1986 ◽  
Vol 77 ◽  
Author(s):  
Taeil Kim ◽  
DDL Chung ◽  
S Mahajan
Keyword(s):  
Gaas Substrate ◽  
Ternary Phase ◽  
Annealing Temperature ◽  
Interfacial Structure ◽  
Lattice Image ◽  
Au Film ◽  
Transmission Electron ◽  
Diffraction Patterns ◽  
Current Flows ◽  
Metallurgical Reactions

ABSTRACTTransmission electron microscopy (TEM), was used to study the interfacial structure resulting from the alloying reaction of a Au/Ge/Au film on (100) GaAs. The metallurgical reaction at 400°C results in the previously unknown hexagonal Au3Ga phase. The crystal structure of the AuoGa phase is proposed based on the observed diffraction patterns and the lattice image The well-known fcchcp coherent jnterface is observed between Au and Au3Ga such that (111)Au // (0001)Au3Ga and [110]. // [1120]Au2Ga. In addition to Au3Ga, other Au-Ga compounds (Au7Ga2, Au2Ge), a Au-Ge metastabil phase, and a Au-Ge-As ternary phase were observed after annealing. After annealing above 400°C, epitaxially regrown GaAs crystallites on the underlying GaAs substrate were revealed by cross-section TEM. The current flows through these Ge-doped regrown GaAs regions and the contact becomes ohmic The size and density of the regrown GaAs crystallite increase with increasing annealing temperature between 400 and 500°C; this explains the decreasing tendency of contact resistance with increasing annealing temperature.

scholarly journals Two-Round Ca 2+ transient in papillae by mechanical stimulation induces metamorphosis in the ascidian Ciona intestinalis type A

2021 ◽  
Vol 288 (1945) ◽  
pp. 20203207
Author(s):  
Maiki K. Wakai ◽  
Mitsuru J. Nakamura ◽  
Satoshi Sawai ◽  
Kohji Hotta ◽  
Kotaro Oka
Keyword(s):  
Phase I ◽  
Phase Ii ◽  
Mechanical Stimulation ◽  
Marine Invertebrate ◽  
Ciona Intestinalis ◽  
Type A ◽  
Early Event ◽  
Second Phase ◽  
Invertebrate Larvae ◽  
Phase Phase

Marine invertebrate larvae are known to begin metamorphosis in response to environmentally derived cues. However, little is known about the relationships between the perception of such cues and internal signalling for metamorphosis. To elucidate the mechanism underlying the initiation of metamorphosis in the ascidian, Ciona intestinalis type A ( Ciona robusta ), we artificially induced ascidian metamorphosis and investigated Ca 2+ dynamics from pre- to post-metamorphosis. Ca 2+ transients were observed and consisted of two temporally distinct phases with different durations before tail regression which is the early event of metamorphosis. In the first phase, Phase I, the Ca 2+ transient in the papillae (adhesive organ of the anterior trunk) was coupled with the Ca 2+ transient in dorsally localized cells and endoderm cells just after mechanical stimulation. The Ca 2+ transients in Phase I were also observed when applying only short stimulation. In the second phase, Phase II, the Ca 2+ transient in papillae was observed again and lasted for approximately 5–11 min just after the Ca 2+ transient in Phase I continued for a few minutes. The impaired papillae by Foxg -knockdown failed to induce the second Ca 2+ transient in Phase II and tail regression. In Phase II, a wave-like Ca 2+ propagation was also observed across the entire epidermis. Our results indicate that the papillae sense a mechanical cue and two-round Ca 2+ transients in papillae transmits the internal metamorphic signals to different tissues, which subsequently induces tail regression. Our study will help elucidate the internal mechanism of metamorphosis in marine invertebrate larvae in response to environmental cues.

Nucleation of Disorder in Fe3Al Alloys

1967 ◽  
Vol 25 ◽  
pp. 312-313
Author(s):  
P. R. Swann ◽  
W. R. Duff ◽  
R. M. Fisher
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Annealing Temperature ◽  
Antiphase Domain ◽  
Effect Of Temperature ◽  
Domain Structures ◽  
Transmission Electron ◽  
Domain Boundaries ◽  
Higher Temperature ◽  
The One

Recently we have investigated the phase equilibria and antiphase domain structures of Fe-Al alloys containing from 18 to 50 at.% Al by transmission electron microscopy and Mössbauer techniques. This study has revealed that none of the published phase diagrams are correct, although the one proposed by Rimlinger agrees most closely with our results to be published separately. In this paper observations by transmission electron microscopy relating to the nucleation of disorder in Fe-24% Al will be described. Figure 1 shows the structure after heating this alloy to 776.6°C and quenching. The white areas are B2 micro-domains corresponding to regions of disorder which form at the annealing temperature and re-order during the quench. By examining specimens heated in a temperature gradient of 2°C/cm it is possible to determine the effect of temperature on the disordering reaction very precisely. It was found that disorder begins at existing antiphase domain boundaries but that at a slightly higher temperature (1°C) it also occurs by homogeneous nucleation within the domains. A small (∼ .01°C) further increase in temperature caused these micro-domains to completely fill the specimen.

Transmission Electron Microscopy studies of the vacancy ordering in YSI2-X thin films

1991 ◽  
Vol 49 ◽  
pp. 562-563
Author(s):  
F.-R. Chen ◽  
T. L. Lee ◽  
L. J. Chen
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Thin Films ◽  
Diffraction Pattern ◽  
Annealing Temperature ◽  
Lattice Mismatch ◽  
Si Substrate ◽  
Metal Thin Films ◽  
Transmission Electron ◽  
Vacancy Ordering

YSi2-x thin films were grown by depositing the yttrium metal thin films on (111)Si substrate followed by a rapid thermal annealing (RTA) at 450 to 1100°C. The x value of the YSi2-x films ranges from 0 to 0.3. The (0001) plane of the YSi2-x films have an ideal zero lattice mismatch relative to (111)Si surface lattice. The YSi2 has the hexagonal AlB2 crystal structure. The orientation relationship with Si was determined from the diffraction pattern shown in figure 1(a) to be and . The diffraction pattern in figure 1(a) was taken from a specimen annealed at 500°C for 15 second. As the annealing temperature was increased to 600°C, superlattice diffraction spots appear at position as seen in figure 1(b) which may be due to vacancy ordering in the YSi2-x films. The ordered vacancies in YSi2-x form a mesh in Si plane suggested by a LEED experiment.

Growth of near noble metal Pd and Pt thin film silicides morphology and structure

1984 ◽  
Vol 42 ◽  
pp. 498-499
Author(s):  
E. I. Alessandrini ◽  
M. O. Aboelfotoh
Keyword(s):  
Noble Metals ◽  
Annealing Temperature ◽  
Chemical Compounds ◽  
Barrier Properties ◽  
Solid State Reactions ◽  
Transmission Electron ◽  
Stable Chemical ◽  
Metal Thickness ◽  
Amorphous Si ◽  
Si Films

Considerable interest has been generated in solid state reactions between thin films of near noble metals and silicon. These metals deposited on Si form numerous stable chemical compounds at low temperatures and have found applications as Schottky barrier contacts to silicon in VLSI devices. Since the very first phase that nucleates in contact with Si determines the barrier properties, the purpose of our study was to investigate the silicide formation of the near noble metals, Pd and Pt, at very thin thickness of the metal films on amorphous silicon.Films of Pd and Pt in the thickness range of 0.5nm to 20nm were made by room temperature evaporation on 40nm thick amorphous Si films, which were first deposited on 30nm thick amorphous Si3N4 membranes in a window configuration. The deposition rate was 0.1 to 0.5nm/sec and the pressure during deposition was 3 x 10 -7 Torr. The samples were annealed at temperatures in the range from 200° to 650°C in a furnace with helium purified by hot (950°C) Ti particles. Transmission electron microscopy and diffraction techniques were used to evaluate changes in structure and morphology of the phases formed as a function of metal thickness and annealing temperature.

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