scholarly journals Photoluminescence in Raman Scattering: Effects of HfO2 Template Layer on Ultrananocrystalline Diamond (UNCD) Films Grown on Stainless Steel Substrates

2018 ◽  
Vol 3 (1) ◽  
pp. 263
Author(s):  
Elida De Obaldia ◽  
Pablo Tirado ◽  
Jesús Alcantar ◽  
Jorge Montes ◽  
Orlando Auciello
Keyword(s):  
Stainless Steel ◽  
Raman Scattering ◽  
Polycrystalline Diamond ◽  
Critical Issue ◽  
Interface Layer ◽  
Hafnium Dioxide ◽  
Ultrananocrystalline Diamond ◽  
Ss Substrates ◽  
The One ◽  
Interface Layers

The growth of polycrystalline diamond films can play an important role in industry if they can be grown on industrially used materials like aluminum (Al) or stainless steel (SS).   A critical issue related to the growth of ultrananocrystalline diamond (UNCD) thin films on metals like SS, in a Hydrogen rich environment like the one present during growth of UNCD films, is the diffusion of Hydrogen (H) into the SS substrate, as it has been observed in prior research, which results in hydride formation in the SS that induce brittleness in the SS substrate.  Several interface layers have been proposed described to avoid the H diffusion into the SS. However, HfO2 has not been explored.  The work reported here was focused on investigating the growth of UNCD films on commercially available SS substrates by using an interface layer of HfO2, which was found to be a good diffusion barrier for H to inhibit penetration into the SS substrate. The samples where characterized with SEM and Raman spectroscopy.  A photoluminescence (PL) effect, observed in the Raman scattering analysis, is present in all the samples.  The PL effect may be due to the interaction of the UNCD / HfO2 interface. and the SS substrate rather than UNCD film alone.  The novel result from the experiments described here, is the fact that it is possible to grow UNCD films on unseeded HfO2 layers on SS substrates.Keywords: Poly-crystalline diamond, photoluminescence, UNCD, Stainless Steel, Hafnium Dioxide 

Influences of Plasma Processed Interface Layers on Germanium MOS Devices with ALD Grown HfO2

2007 ◽  
Vol 996 ◽  
Author(s):  
Takuya Sugawara ◽  
Raghavasimhan Sreenivasan ◽  
Yasuhiro Oshima ◽  
Paul C. McIntyre
Keyword(s):  
Electrical Properties ◽  
Interface Layer ◽  
Hafnium Dioxide ◽  
Passivation Layer ◽  
Oxide Semiconductor ◽  
Flat Band ◽  
Mos Capacitors ◽  
Mos Devices ◽  
Interface Layers ◽  
Silicon Based

AbstractGermanium and hafnium-dioxide (HfO2) stack structures' physical and electrical properties were studied based on the comparison of germanium and silicon based metal-oxide-semiconductor (MOS) capacitors' electrical properties. In germanium MOS capacitor with oxide/oxynitride interface layer, larger negative flat-band-voltage (Vfb) shift compared with silicon based MOS capacitors was observed. Secondary ion mass spectrum (SIMS) characteristics of HfO2-germanium stack structure with germanium oxynitride (GeON) interfacial layer showed germanium out diffusion into HfO2. These results indicate that the germanium out diffusion into HfO2 would be the origin of the germanium originated negative Vfb shift. Using Ta3N5 layer as a germanium passivation layer, reduced Vfb shift and negligible hysteresis were observed. These results suggest that the selection of passivation layer strongly influences the electrical properties of germanium based MOS devices.

Gallium Arsenide Layers Grown By Mbe on Germanium Islands on Insulator

1985 ◽  
Vol 53 ◽  
Author(s):  
M. Takai ◽  
Y. Kodama ◽  
T. Tanigawa ◽  
K. Kobayashi ◽  
K. Gamo ◽  
...  
Keyword(s):  
Gallium Arsenide ◽  
Raman Scattering ◽  
Band Gap ◽  
Residual Strain ◽  
Local Variation ◽  
Interface Layer ◽  
Zone Melting ◽  
Pl Spectra ◽  
Interface Layers ◽  
Good Agreement

ABSTRACTLocal variation of photoluminescence (PL) spectra for MBE GaAs grown on an insulating substrate with Ge-islands interface layers, prepared by zone melting recrystallization, has been investigated. The GaAs layers on the single crystalline Ge islands emit PL, the intensity of which was almost comparable to that of the GaAs layers on bulk Ge, while by a factor of 50 lower PL intensity was observed for the GaAs layers on Si02. PL spectra were found to show peak shifts due to the band-gap variation near the interface layer of GaAs, which was in good agreement with the residual strain obtained by microprobe Raman scattering for underlying Ge islands.

Preparation of Electron Transparent Metal-Matrix Composites

1968 ◽  
Vol 26 ◽  
pp. 334-335 ◽  
Author(s):  
M. R. Pinnel ◽  
A. Lawley
Keyword(s):  
Stainless Steel ◽  
Load Transfer ◽  
Volume Fraction ◽  
Steel Wire ◽  
Initial Step ◽  
Interfacial Region ◽  
Matrix Composites ◽  
Specific Test ◽  
The Matrix ◽  
The One

Numerous phenomenological descriptions of the mechanical behavior of composite materials have been developed. There is now an urgent need to study and interpret deformation behavior, load transfer, and strain distribution, in terms of micromechanisms at the atomic level. One approach is to characterize dislocation substructure resulting from specific test conditions by the various techniques of transmission electron microscopy. The present paper describes a technique for the preparation of electron transparent composites of aluminum-stainless steel, such that examination of the matrix-fiber (wire), or interfacial region is possible. Dislocation substructures are currently under examination following tensile, compressive, and creep loading. The technique complements and extends the one other study in this area by Hancock.The composite examined was hot-pressed (argon atmosphere) 99.99% aluminum reinforced with 15% volume fraction stainless steel wire (0.006″ dia.).Foils were prepared so that the stainless steel wires run longitudinally in the plane of the specimen i.e. the electron beam is perpendicular to the axes of the wires. The initial step involves cutting slices ∼0.040″ in thickness on a diamond slitting wheel.

Comparative study on e-bikes’ decision-making behaviors under flashing green and green countdown

2021 ◽  
pp. 1-8
Author(s):  
Haoyang Meng ◽  
Sheng Dong ◽  
Jibiao Zhou ◽  
Shuichao Zhang ◽  
Zhenjiang Li
Keyword(s):  
Decision Making ◽  
Critical Issue ◽  
Trajectory Data ◽  
Decision Points ◽  
Binary Logit ◽  
The One ◽  
Common Signal ◽  
And Function ◽  
Decision Behaviors ◽  
Stop Line

Green flash light (FG) and green countdown (GC) are the two most common signal formats applied in green-red transition that provides drivers additional alert before termination of green phase. Due to their importance and function in stop-pass decision-making process, proper use of them has become a critical issue to greatly improve the safety and efficiency of signalized intersections. Gradually e-bike riders have become more important commuters in China, however, the influence of FG or GC on them is not clear yet and need pay more attention to it. This study chooses two almost identical intersections to obtain highly accurate trajectory data of e-bike riders to study their decision-making behaviors under FG or GC. The e-bike riders’ behavior is classified into four categories and is to identify their stop-pass decision points using the acceleration trend. Two binary-logit models were built to predict the stop–pass decision behaviors for the different e-bike rider groups, explaining that the potential time to the stop-line is the dominant independent factor of the different behaviors of GC and FG. Furthermore empirical analysis of decision points indicated that GC provides the earlier stop-pass decision point and longer decision making duration on the one side while results in more complexity of decision making and greater risk of stop-line crossing than FG on the other side.

scholarly journals Critical Issues: What Counts When Context Counts?: The Uncommon “Common” Language of Literacy Research

1998 ◽  
Vol 30 (3) ◽  
pp. 405-433 ◽  
Author(s):  
Lesley Rex ◽  
Judith Green ◽  
Carol Dixon ◽  
Santa Barbara ◽  
Keyword(s):  
Research Methods ◽  
English Education ◽  
Critical Issue ◽  
Common Language ◽  
Confounding Effect ◽  
Theoretical Perspectives ◽  
Common Term ◽  
Critical Issues ◽  
The One ◽  
Literacy Research

Research into literacy published in journals such as the Journal of Literacy Research spans a range of disciplines and areas of study (e.g., reading, English education, composition). Even individual studies frequently take up interdisciplinary perspectives (e.g., anthropological, sociological, linguistic, educational, textual). The results are journals far ranging in their reach and rich in the knowledge they bring to literacy issues. However, such diversity of theoretical perspectives, research methods, and analytical methodologies also contributes to a confounding effect. In this article, we explore one such effect that occurs when a common term is used with different meanings. Although this may appear on the surface to be a problem easily remedied or even a rather trivial issue, in this article, we show just how consequential this practice can be when the goal is building knowledge from research that can inform practice, policy, and theory. This critical issue can be posed as a set of interrelated questions: Are we all talking about the same thing when we use words like literacy, reading, and even seemingly less resonant ones like context, the one addressed in this commentary? If we are, how do we know? And if we are not, what price are we paying for not considering the issue?

Characterization of Mg-Al Sheet Clad Materials Fabricated by Hot Rolling

2007 ◽  
Vol 26-28 ◽  
pp. 409-412 ◽  
Author(s):  
Jae Seol Lee ◽  
Hyeon Taek Son ◽  
Ki Yong Lee ◽  
Soon Sub Park ◽  
Dae Guen Kim ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Vickers Hardness ◽  
Hot Rolling ◽  
High Strength ◽  
Interface Layer ◽  
Rolling Temperature ◽  
Al Alloy ◽  
Clad Sheet ◽  
The Difference ◽  
Interface Layers

AZ31 Mg / 5083 Al clad sheet was fabricated by the hot rolling method and its mechanical properties were investigated in this study. The tensile strength and yield strength of Mg- Al clad samples were slightly higher than that of AZ31 Mg sample, resulting in high strength 5083 Al alloy. Also, in the case of the AZ31 Mg sample, tensile strength indicated different values to the rolling directions. The thickness of interface layers between magnesium and aluminum materials increased with increasing rolling temperature. The thickness of interface layer was about 1.2 μm and 1.6 μm, respectively. The difference of thickness on the interface layer with variation of rolling temperature was attributed to promote the diffusion between magnesium and aluminum materials. The Vickers hardness of Mg-Al interface layer was around 125 Hv. The interface layer composed of hard inter-metallic phases which may act a increment of Vickers hardness depending upon its thickness.

Reductions and Solutions of Two Types of Coupled Nonlinear Evolution Equations in Optical Fibers and Fluid Dynamics

2011 ◽  
Vol 66 (8-9) ◽  
pp. 552-558
Author(s):  
Li-Cai Liu ◽  
Bo Tian ◽  
Bo Qin ◽  
Xing Lü ◽  
Zhi-Qiang Lin ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Raman Scattering ◽  
Optical Fibers ◽  
Evolution Equations ◽  
Nonlinear Evolution ◽  
Dark Soliton ◽  
Nonlinear Evolution Equations ◽  
The One ◽  
Gain Loss ◽  
Burgers Type Equations

Abstract Under investigation in this paper are the coupled nonlinear Schrödinger equations (CNLSEs) and coupled Burgers-type equations (CBEs), which are, respectively, a model for certain birefringent optical fibers Raman-scattering, Kerr and gain/loss effects, and a generalized model in fluid dynamics. Special attention should be paid to the existing claim that the solitons for the CNLSEs do not exist. Through certain dependent-variable transformations, the CNLSEs are reduced to a Manakov system and the CBEs are linearized. In that way, some new solutions of the CNLSEs and CBEs are obtained via symbolic computation. Especially the one-dark-soliton-like solutions for the CNLSEs have been found, against the existing claim.

Water Access in the Fight Against Poverty

2013 ◽  
pp. 315-325
Author(s):  
Diego Azqueta ◽  
Álvaro Montoya
Keyword(s):  
Water Footprint ◽  
Positive Impact ◽  
Rural Poverty ◽  
Critical Issue ◽  
Limiting Factor ◽  
Multiple Use ◽  
Potential Conflict ◽  
Access To Water ◽  
Tourist Development ◽  
The One

Rural poverty in underdeveloped countries is a critical issue. A fair amount of literature exists examining the conditions of pro-poor tourism development, as well as different ways to fight it. However, in some cases, and because of the existence of a limiting factor, a potential incompatibility between tourist development and other strategies can emerge, as well as the need to compare relative efficiency. An example of this potential conflict is the one posed by tourist development and the Multiple Use of Water Services strategy (MUS) to alleviate rural poverty. In this case, the limiting constraint is access to water. This paper analyses the impacts, direct and indirect, on poverty levels, of tourist development and MUS. the authors examine the Quindío Region in Colombia, where the MUS strategy is being implemented and where an ambitious tourist development plan may open social conflict regarding water supply. The results of this analysis shows that, even if the MUS strategy has a greater positive impact on poverty alleviation, in terms of income and employment generated per unit of water, its water footprint, contrary to expectations, is much higher than the one corresponding to the tourist sector. This may jeopardize its future development, calling for a more balanced approach.

scholarly journals Development of an assembly for the realization of a transducer able to operate at very high temperatures

2019 ◽  
Vol 283 ◽  
pp. 07011
Author(s):  
Didier Flotté ◽  
David Macel ◽  
Abd Ennour Bouzenad ◽  
Frédéric Navacchia
Keyword(s):  
Stainless Steel ◽  
High Temperatures ◽  
Nuclear Reactor ◽  
New Technology ◽  
Operating Conditions ◽  
Equivalent Diameter ◽  
Assembly Technique ◽  
The One ◽  
Piezoelectric Disc ◽  
Very High

Monitoring the operation of the latest-generation nuclear reactor requires ultrasonic transducers able to operate at very high temperatures (> 600°C). To achieve this, CEA has requested from “Institut de Soudure” to help developing a new technology for these transducers compared to the one previously developed. This began with the development of a reliable assembly technique between a lithium niobate piezoelectric disc whose Curie temperature exceeds 1100°C and stainless steel discs. The chosen solution was to braze the niobate disc between two stainless steel discs. Parallel to this development, it was also necessary to develop a NDE procedure to verify the quality of the brazing assemblies. This development began with a simulation of immersion ultrasonic testing of the assemblies. The constraints were to be able to control the two brazed interfaces from the same access face, with the possibility of detecting and dimensioning defects with an equivalent diameter of 0.25 mm. This phase is important to define the optimal transducer with the associated operating conditions. The first assemblies validated the preliminary choices. To exploit the cartographies obtained, a signal processing procedure was developed. This enabled an automatic characterization of the indications observed. However, the analysis of the signals observed proved to be more complex than the one predicted by the simulation. Once the origin of the various observed signals was identified it was then possible to define windows allowing the construction of the cartographies to analyze. In case of a good quality assembly, it was possible to qualify the generated beam and to image it in the focal plane but with an observed signal having a very low damping. These first encouraging results, however, show that there is still some validation and development work to increase the sensitivity of the developed translator and its damping.

A Study on Warm Micro Backward Extrusion of SUS 304 Stainless Steel

2011 ◽  
Vol 486 ◽  
pp. 139-142
Author(s):  
Chao Cheng Chang ◽  
Dinh Hiep Nguyen ◽  
Hsin Sheng Hsiao
Keyword(s):  
Stainless Steel ◽  
Metal Forming ◽  
Material Flow ◽  
Elevated Temperatures ◽  
304 Stainless Steel ◽  
Electrical Heater ◽  
Backward Extrusion ◽  
Water Based ◽  
Inner Diameter ◽  
The One

A metal forming system comprising an electrical heater, capable of conducting processes at elevated temperatures, was developed to perform micro backward extrusion processes of SUS 304 stainless steel. Two punches with diameters of 1.6 mm and 1.8 mm were used to extrude the billets inside the die with an inner diameter of 2 mm. All processes were lubricated with water-based graphite and conducted under isothermal conditions at 400 °C. The results show that the developed extrusion system can be used to produce the stainless steel components with a micro cup-shaped profile. Moreover, the variation in the rim height of the cups produced by the 1.8 mm diameter punch is greater than the one by the 1.6 mm diameter punch. The results show that a decrease in the clearance between the punch and die could lead to an increase in the inhomogeneity of material flow in the micro backward extrusion processes.

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