scholarly journals The effects of the global surface curvature on Makyoh-topogaphy imaging

2019 ◽  
Vol 11 (1) ◽  
pp. 4
Author(s):  
Ferenc Riesz
Keyword(s):  
Optical Model ◽  
Image Formation ◽  
Practical Applications ◽  
Manufacturing Method ◽  
Curvature Measurements ◽  
Global Curvature ◽  
Reflecting Surface ◽  
Wafer Surfaces ◽  
Sample Distance

The effects of the global curvature of the reflecting surface on Makyoh (magic-mirror) topography imaging is analysed based on a geometrical optical model. It is shown that the effects can be taken into account by introducing an equivalent screen-to-sample distance which is a function of the real screen-to-sample distance and the global curvature. The special limiting cases are discussed and analysed for practical applications. Full Text: PDF ReferencesK. Kugimiya, "“Makyoh”: The 2000 year old technology still alive", J. Cryst. Growth 103, 420 (1990). CrossRef P. Blaustein, S. Hahn, "Realtime inspection of wafer surfaces", Solid State Technol. 32, 27 (1989). CrossRef Z.J. Pei, G.R. Fisher, M. Bhagavat, S. Kassir, "A grinding-based manufacturing method for silicon wafers: an experimental investigation", Int. J. Machine Tools Manufacture 45, 1140 (2005). CrossRef F. Riesz, "Makyoh topography: a simple yet powerful optical method for flatness and defect characterization of mirror-like surfaces", Proc. SPIE 5458, 86 (2004). CrossRef T. Hirogaki, E. Aoyama, R. Machinaka, H. Sueda, K. Ogawa, J. Japan Soc. Precision Eng. 73, 96 (2007). CrossRef G. Saines, M.G. Tomilin, "Magic mirrors of the Orient", J. Opt. Technol. 66, 758 (1999). CrossRef W.E. Ayrton, J. Perry, "The Magic Mirror of Japan. Part I", Proc. Roy. Soc. London 28, 127 (1878). CrossRef M.V. Berry, "Oriental magic mirrors and the Laplacian image", Eur. J. Phys. 27, 109 (2006). CrossRef F. Riesz, "Sensitivity and detectability in Makyoh imaging", Optik 122, 2115 (2011). CrossRef Z.J. Laczik, "Quantitative Makyoh topography", Opt. Eng. 39, 2562 (2000). CrossRef F. Riesz, "Geometrical optical model of the image formation in Makyoh (magic-mirror) topography", J. Phys. D: Appl. Phys. 33, 3033 (2000). CrossRef F. Riesz, "Camera length and field of view in Makyoh-topography instruments", Rev. Sci. Instr. 72, 1591 (2001). CrossRef J. Szabó, F. Riesz, B. Szentpáli, "Makyoh Topography: Curvature Measurements and Implications for the Image Formation", Japan. J. Appl. Phys. 35, L258 (1996). CrossRef F. Riesz, "Non-linearity and related features of Makyoh (magic-mirror) imaging", J. Opt. 15, 075709 (2013). CrossRef A.V. Gitin, "System approach to image formation in a magic mirror", Appl. Opt. 48, 1268 (2009). CrossRef

Characterization of intergranular cuprous oxide in polycrystalline YBa2Cu3O7-x

1988 ◽  
Vol 46 ◽  
pp. 880-881
Author(s):  
Bradley L. Thiel ◽  
Chan Han R. P. ◽  
Kurosky L. C. Hutter ◽  
I. A. Aksay ◽  
Mehmet Sarikaya
Keyword(s):  
Grain Boundary ◽  
Cuprous Oxide ◽  
Room Temperature ◽  
Boundary Phase ◽  
Spectroscopic Techniques ◽  
Transition Width ◽  
Practical Applications ◽  
Thin Foils ◽  
Superconducting Oxides

The identification of extraneous phases is important in understanding of high Tc superconducting oxides. The spectroscopic techniques commonly used in determining the origin of superconductivity (such as RAMAN, XPS, AES, and EXAFS) are surface-sensitive. Hence a grain boundary phase several nanometers thick could produce irrelevant spectroscopic results and cause erroneous conclusions. The intergranular phases present a major technological consideration for practical applications. In this communication we report the identification of a Cu2O grain boundary phase which forms during the sintering of YBa2Cu3O7-x (1:2:3 compound).Samples are prepared using a mixture of Y2O3. CuO, and BaO2 powders dispersed in ethanol for complete mixing. The pellets pressed at 20,000 psi are heated to 950°C at a rate of 5°C per min, held for 1 hr, and cooled at 1°C per min to room temperature. The samples show a Tc of 91K with a transition width of 2K. In order to prevent damage, a low temperature stage is used in milling to prepare thin foils which are then observed, using a liquid nitrogen holder, in a Philips 430T at 300 kV.

Processing and characterization of YBa2Cu3O7−x/Ag composites

1990 ◽  
Vol 48 (4) ◽  
pp. 46-47
Author(s):  
Jafar Javadpour ◽  
Bradley L. Thiel ◽  
Sarikaya Mehmet ◽  
Ilhan A. Aksay
Keyword(s):  
Composite System ◽  
Precursor Solution ◽  
Microstructural Development ◽  
Superconducting Properties ◽  
Practical Applications ◽  
Nitrate Precursor ◽  
Cold Pressed ◽  
Tape Cast ◽  
Composite Samples

Practical applications of bulk YBa2Cu3O7−x materials have been limited because of their inadequate critical current density (jc) and poor mechanical properties. Several recent reports have indicated that the addition of Ag to the YBa2Cu3O7−x system is beneficial in improving both mechanical and superconducting properties. However, detailed studies concerning the effect of Ag on the microstructural development of the cermet system have been lacking. Here, we present some observations on the microstructural evolution in the YBa2Cu3O7−x/Ag composite system.The composite samples were prepared by mixing various amounts (2.5 - 50 wt%) AgNO3 in the YBa2Cu3O7−x nitrate precursor solution. These solutions were then spray dried and the resulting powders were either cold pressed or tape cast. The microstructures of the sintered samples were analyzed using SEM (Philips 515) and an analytical TEM (Philips 430T).The SEM micrographs of the compacts with 2.5 and 50 wt% Ag addition sintered at 915°C (below the melting point of Ag) for 1 h in air are displayed in Figs. 1 and 2, respectively.

scholarly journals A New Statistical Biomechanics Modeling of Physical and Biochemical Bone Strength Parameters

2000 ◽  
Author(s):  
Alfred B. O. Soboyejo ◽  
Karl E. Nestor
Keyword(s):  
Bone Strength ◽  
Biochemical Parameters ◽  
Broiler Chickens ◽  
Management Practices ◽  
Physical Parameters ◽  
Structural Failure ◽  
Practical Applications ◽  
Good Management ◽  
Biomechanical Parameters

Abstract New multiparameter biomechanics models are developed in this work for the characterization of bone strengths in broiler chickens and turkeys, as functions of the major physical and biochemical parameters, which can contribute to mechanical properties of bone strengths in these birds, under good management practices. Theoretical and experimental methods have been developed in this study to model bone strength as functions of (a) the physical parameters only and (b) the biochemical parameters only, which can affect bone strength. The choice of any particular methodology will depend on the availability of either the physical or biochemical parameters, which can be obtained from experimental data. Possible useful practical applications of the statistical biomechanics principles developed in this technical paper, particularly in the field of bone strength enhancement in turkeys and broiler chickens will be discussed. In view of the problems described, the major objectives of the present study are as follows: (1) To develop new multiparameter biomechanics models for the characterization of bone strengths in turkeys and broiler chickens as functions of the major physical only, or biomechanical parameters only, which can contribute to bone strength in these birds, under conditions of good management of these birds. This study will consider only the compressive buckling as the mode of structural failure in the cellular material of the bone. (2) To highlight briefly the possible practical applications of the statistical biomechanics principles, which will be developed in this study to the genetic improvement of bone strengths in broiler chickens and turkeys.

Implementation, Characterization and Application of Path Changing Switch based Arbiter PUF on FPGA as a lightweight Security Primitive for IoT

2022 ◽  
Vol 27 (3) ◽  
pp. 1-26
Author(s):  
Mahabub Hasan Mahalat ◽  
Suraj Mandal ◽  
Anindan Mondal ◽  
Bibhash Sen ◽  
Rajat Subhra Chakraborty
Keyword(s):  
Complete Characterization ◽  
Effect Of Temperature ◽  
Practical Applications ◽  
Gate Arrays ◽  
Heterogeneous Technologies ◽  
Field Programmable ◽  
Arbiter Puf ◽  
Programmable Gate Arrays ◽  
Secure Authentication

Secure authentication of any Internet-of-Things (IoT) device becomes the utmost necessity due to the lack of specifically designed IoT standards and intrinsic vulnerabilities with limited resources and heterogeneous technologies. Despite the suitability of arbiter physically unclonable function (APUF) among other PUF variants for the IoT applications, implementing it on field-programmable gate arrays (FPGAs) is challenging. This work presents the complete characterization of the path changing switch (PCS) 1 based APUF on two different families of FPGA, like Spartan-3E (90 nm CMOS) and Artix-7 (28 nm CMOS). A comprehensive study of the existing tuning concept for programmable delay logic (PDL) based APUF implemented on FPGA is presented, leading to establishment of its practical infeasibility. We investigate the entropy, randomness properties of the PCS based APUF suitable for practical applications, and the effect of temperature variation signifying the adequate tolerance against environmental variation. The XOR composition of PCS based APUF is introduced to boost performance and security. The robustness of the PCS based APUF against machine learning based modeling attack is evaluated, showing similar characteristics as the conventional APUF. Experimental results validate the efficacy of PCS based APUF with a little hardware footprint removing the paucity of lightweight security primitive for IoT.

Synthesis and Characterization of Zirconium Metal Complexes Derived from Benzene-1, 4-dicarboxylic acid

2020 ◽  
Vol 42 (6) ◽  
pp. 919-919
Author(s):  
Hafiz Muhammad Arshad Hafiz Muhammad Arshad ◽  
Shazia Khurshid Shazia Khurshid ◽  
Shahzad Sharif Shahzad Sharif ◽  
Muhammad Ali Muhammad Ali ◽  
Muhammad Dilshad Muhammad Dilshad ◽  
...  
Keyword(s):  
Metal Complexes ◽  
Dicarboxylic Acid ◽  
Terephthalic Acid ◽  
Research Work ◽  
Early Developmental Stage ◽  
Practical Applications ◽  
Secondary Building Units ◽  
Ft Ir ◽  
Zirconium Metal

Amongst organo-metallic frameworks (OMFs), the metallic framework having Zirconium metal indicate fascinating structural properties and excellent stability. Such organo-metallic frameworks (OMFs) function as a potential material for practical application. Even though these particular organo-metallic frameworks are in the early developmental stage but considerable advancements have been carried out recently. We studied the characterization of zirconium-based organo-metallic frameworks. We built Zr-based OMFs by four different synthetic ways. Initially, upgraded preparation under green and commercially feasible conditions has been carried out by modifying Zr-OMFs. Zirconium based OMFs having different structures are then classified and explained based on various organic ligands and zirconium-based secondary building units. We have synthesized the zirconium metal complexes; they have been characterized on the bases of FT-IR and CHNS analyzer. FT-IR results show binding of metal with the Benzene-1, 4-dicarboxylic acid [C6H4 (COOH) 2]. Zirconium metal can bind with the organic substances for the construction of a variety of complexes. From my research work, it is concluded that zirconium metal forms a polymeric complex with terephthalic acid. In which oxygen atoms of Terephthalic acid form bridging structure with the zirconium metal. Our study based on a particular type of OMF is likely expected to present guidance for in-depth exploration of OMFs towards practical applications. It is concluded that the metal-organic frameworks (MOFs) of zirconium metal have many applications in the field of chemistry, biology and other numerous fields of science

Some new approaches to probability distributions

1980 ◽  
Vol 12 (04) ◽  
pp. 903-921 ◽  
Author(s):  
S. Kotz ◽  
D. N. Shanbhag
Keyword(s):  
Probability Distributions ◽  
Random Variables ◽  
Representation Theorems ◽  
Practical Applications ◽  
New Approaches ◽  
Characterization Of Distributions ◽  
Stability Theorems ◽  
Conditional Expectations

We develop some approaches to the characterization of distributions of real-valued random variables, useful in practical applications, in terms of conditional expectations and hazard measures. We prove several representation theorems generalizing earlier results, and establish stability theorems for two general characteristics introduced in this paper.

scholarly journals Fabrication of Ultra-High Aspect Ratio (>420:1) Al2O3 Nanotube Arraysby Sidewall TransferMetal Assistant Chemical Etching

Micromachines ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 378 ◽  
Author(s):  
Hailiang Li ◽  
Changqing Xie
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Chemical Etching ◽  
Atomic Layer ◽  
Nanotube Arrays ◽  
Al2o3 Layer ◽  
Practical Applications ◽  
Aspect Ratios ◽  
Layer Deposition

We report a robust, sidewall transfer metal assistant chemical etching scheme for fabricating Al2O3 nanotube arrays with an ultra-high aspect ratio. Electron beam lithography followed by low-temperature Au metal assisted chemical etching (MacEtch) is used to pattern high resolution, high aspect ratio, and vertical silicon nanostructures, used as a template. This template is subsequently transferred by an atomic layer deposition of the Al2O3 layer, followed by an annealing process, anisotropic dry etching of the Al2O3 layer, and a sacrificial silicon template. The process and characterization of the Al2O3 nanotube arrays are discussed in detail. Vertical Al2O3 nanotube arrays with line widths as small as 50 nm, heights of up to 21 μm, and aspect ratios up to 420:1 are fabricated on top of a silicon substrate. More importantly, such a sidewall transfer MacEtch approach is compatible with well-established silicon planar processes, and has the benefits of having a fully controllable linewidth and height, high reproducibility, and flexible design, making it attractive for a broad range of practical applications.

scholarly journals Applied Sciences Special Issue: Ultrasonic Guided Waves

2019 ◽  
Vol 9 (18) ◽  
pp. 3869 ◽  
Author(s):  
Clifford J. Lissenden
Keyword(s):  
Applied Sciences ◽  
Scientific Inquiry ◽  
Guided Waves ◽  
Ultrasonic Guided Waves ◽  
Special Issue ◽  
Practical Applications ◽  
Material State ◽  
Characterization Of Materials ◽  
Nondestructive Characterization

The propagation of ultrasonic guided waves in solids is an important area of scientific inquiry due primarily to their practical applications for the nondestructive characterization of materials, such as nondestructive inspection, quality assurance testing, structural health monitoring, and for achieving material state awareness [...]

scholarly journals The architecture of the diaminobutyrate acetyltransferase active site provides mechanistic insight into the biosynthesis of the chemical chaperone ectoine

2020 ◽  
Vol 295 (9) ◽  
pp. 2822-2838 ◽  
Author(s):  
Alexandra A. Richter ◽  
Stefanie Kobus ◽  
Laura Czech ◽  
Astrid Hoeppner ◽  
Jan Zarzycki ◽  
...  
Keyword(s):  
Site Directed Mutagenesis ◽  
Catalytic Core ◽  
Chemical Chaperone ◽  
Practical Applications ◽  
Acetyl Group ◽  
Function Relationship ◽  
Thermotolerant Bacterium ◽  
Stress Protectant ◽  
Relationship Of

Ectoine is a solute compatible with the physiologies of both prokaryotic and eukaryotic cells and is widely synthesized by bacteria as an osmotic stress protectant. Because it preserves functional attributes of proteins and macromolecular complexes, it is considered a chemical chaperone and has found numerous practical applications. However, the mechanism of its biosynthesis is incompletely understood. The second step in ectoine biosynthesis is catalyzed by l-2,4-diaminobutyrate acetyltransferase (EctA; EC 2.3.1.178), which transfers the acetyl group from acetyl-CoA to EctB-formed l-2,4-diaminobutyrate (DAB), yielding N-γ-acetyl-l-2,4-diaminobutyrate (N-γ-ADABA), the substrate of ectoine synthase (EctC). Here, we report the biochemical and structural characterization of the EctA enzyme from the thermotolerant bacterium Paenibacillus lautus (Pl). We found that (Pl)EctA forms a homodimer whose enzyme activity is highly regiospecific by producing N-γ-ADABA but not the ectoine catabolic intermediate N-α-acetyl-l-2,4-diaminobutyric acid. High-resolution crystal structures of (Pl)EctA (at 1.2–2.2 Å resolution) (i) for its apo-form, (ii) in complex with CoA, (iii) in complex with DAB, (iv) in complex with both CoA and DAB, and (v) in the presence of the product N-γ-ADABA were obtained. To pinpoint residues involved in DAB binding, we probed the structure-function relationship of (Pl)EctA by site-directed mutagenesis. Phylogenomics shows that EctA-type proteins from both Bacteria and Archaea are evolutionarily highly conserved, including catalytically important residues. Collectively, our biochemical and structural findings yielded detailed insights into the catalytic core of the EctA enzyme that laid the foundation for unraveling its reaction mechanism.

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