Processing and Characterization of High-conductance Bismuth Wire Array Composites

2000 ◽  
Vol 15 (8) ◽  
pp. 1816-1821 ◽  
Author(s):  
T. E. Huber ◽  
M. J. Graf ◽  
C. A. Foss ◽  
P. Constant
Keyword(s):  
Volume Fraction ◽  
Wire Array ◽  
Nanowire Array ◽  
Trigonal Axis ◽  
Copper Electrodes ◽  
Bi Nanowire ◽  
The Individual ◽  
Anodic Alumina Templates ◽  
High Pressure Injection

We fabricated Bi nanowire array composites with wire diameters from 30 to 200 nm by high-pressure injection (HPI) of Bi melt into porous anodic alumina templates. The composites were dense, with Bi volume fraction in excess of 50%. The parallel Bi nanowires, whose length appeared to be limited only by the thickness of the host template (up to 55 μm), terminated at both sides of the composite in the Bi bulk. The individual Bi nanowire crystal structure was rhombohedral, with the same lattice parameters as that of bulk Bi; the wires in the array were predominantly oriented with the trigonal axis along the wire length. Low contact resistance was achieved by bonding the composite to copper electrodes.

Optical Properties of Metal Wire Array Composites

1996 ◽  
Vol 457 ◽  
Author(s):  
Laura Luo ◽  
T. E. Huber
Keyword(s):  
Volume Fraction ◽  
Wire Array ◽  
Electrically Conducting ◽  
Microchannel Plates ◽  
Transparent Dielectric ◽  
Effective Medium Theories ◽  
Measured Absorption ◽  
The Wire ◽  
High Pressure Injection ◽  
Metal Wires

ABSTRACTAccording to effective medium theories, electrically conducting composites consisting of parallel metal wires embedded in a transparent dielectric can propagate light in the direction of the wire length. We have prepared densely packed arrays (76% volume fraction) of 10-μm diameter indium wires by high pressure injection of glass microchannel plates. For wavelengths longer than 100 μm (k<100 cm−1) the absorption of the wire array is almost three orders of magnitude smaller than that of an indium foil of equal thickness. The measured absorption increases as k0.45±0.07 and can be accounted for by including magnetic dipole effects.

Thermopower of Bi Nanowire Array Composites.

2000 ◽  
Vol 626 ◽  
Author(s):  
T.E. Huber ◽  
M.J. Graf ◽  
C.A. Foss ◽  
P. Constant
Keyword(s):  
High Pressure ◽  
Seebeck Coefficient ◽  
Contact Resistance ◽  
Nanowire Array ◽  
High Mobility ◽  
Nanowire Arrays ◽  
Pressure Injection ◽  
Dense Arrays ◽  
Bi Nanowire ◽  
High Pressure Injection

The small effective mass and high mobility of electrons in Bi, make Bi nanowires a promising system for thermoelectric applications. Dense arrays of 20–200 nm diameter Bi nanowires were fabricated by high pressure injection of the melt. Transport properties and Seebeck coefficient were investigated for Bi nanowires with various wire diameters as a function of temperature (1 K < T < 300 K) and magnetic fields (B < 0.6 T). We discuss the problem of the contact resistance of Bi nanowire arrays.

Processing, Characterization, and Measurement of the Seebeck Coefficient of Bismuth Microwire Array Composites

2000 ◽  
Vol 626 ◽  
Author(s):  
T.E. Huber ◽  
P. Constant
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Seebeck Coefficient ◽  
Room Temperature ◽  
Volume Fraction ◽  
Lattice Plane ◽  
Crystalline Orientation ◽  
Pressure Injection ◽  
The Individual ◽  
High Pressure Injection

ABSTRACTWe have fabricated Bi microwire array composites ranging in diameter from 10 to 50 micrometer using the method of high-pressure-injection (HPI) of the Bi melt into microchannel arrays (MCA) templates. The composites are dense, with Bi volume fraction in excess of 70 %. The parallel Bi nanowires, whose length appears to be limited only by the thickness of the host template (up to 2 mm), terminate at both sides of the composite in the Bi bulk. The individual Bi microwire crystal structure is rhombohedral, with the same lattice parameters as that of bulk Bi; the wires crystalline orientation is predominantly perpendicular to the (113) lattice plane. The transversal magnetoresistance and Seebeck effect of the wires has been measured in magnetic fields up to 0.8 Tesla and for temperatures ranging between 77 K and room temperature.

Separation and Characterization of Standard Propoxyphene Diastereomers and Their Determination in Pharmaceutical and Illicit Preparations

1981 ◽  
Vol 64 (4) ◽  
pp. 875-883
Author(s):  
Shiv K Soni ◽  
Daniel Van Gelder
Keyword(s):  
High Pressure ◽  
Optical Isomers ◽  
Gold Chloride ◽  
Melting Points ◽  
Eutectic Melting ◽  
Racemic Mixtures ◽  
The Individual ◽  
Isomeric Mixtures ◽  
Asymmetric Carbon

Abstract Due to the existence of 2 asymmetric carbon atoms in: the propoxyphene molecule, there are 4 diastereomers: alpha dextro, alpha levo, beta dextro, and beta levo. Only α-d-propoxyphene is included under the federal Controlled Substances Act. Baseline separations of propoxyphene from various incipients (aspirin, caffeine, phenacetin, and acetaminophen) present in pharmaceutical and illicit preparations, and between the alpha and beta diastereomers, were achieved by high pressure liquid chromatography. The column eluant was collected and propoxyphene was extracted. The optical isomers were differentiated and characterized by melting points and by chemical microcrystalline tests. Using hot stage thermomicroscopy, the eutectic melting points of binary isomeric mixtures of propoxyphene bases and salts were found to be depressed about 10° and 15-30°C, respectively, below the individual isomer melting points. The characteristic microcrystals formed with the alpha racemic mixtures by using a glycerin-aqueous gold chloride reagent were not produced by the beta racemic mixtures.

scholarly journals Does higher education properly prepare graduates for the growing artificial intelligence market? Gaps identification using text mining

2021 ◽  
pp. 1-13
Author(s):  
Lamiae Benhayoun ◽  
Daniel Lang
Keyword(s):  
Artificial Intelligence ◽  
Natural Language Processing ◽  
Text Mining ◽  
Natural Language ◽  
Language Processing ◽  
Academic Training ◽  
Market Requirements ◽  
Job Advertisements ◽  
The Individual

BACKGROUND: The renewed advent of Artificial Intelligence (AI) is inducing profound changes in the classic categories of technology professions and is creating the need for new specific skills. OBJECTIVE: Identify the gaps in terms of skills between academic training on AI in French engineering and Business Schools, and the requirements of the labour market. METHOD: Extraction of AI training contents from the schools’ websites and scraping of a job advertisements’ website. Then, analysis based on a text mining approach with a Python code for Natural Language Processing. RESULTS: Categorization of occupations related to AI. Characterization of three classes of skills for the AI market: Technical, Soft and Interdisciplinary. Skills’ gaps concern some professional certifications and the mastery of specific tools, research abilities, and awareness of ethical and regulatory dimensions of AI. CONCLUSIONS: A deep analysis using algorithms for Natural Language Processing. Results that provide a better understanding of the AI capability components at the individual and the organizational levels. A study that can help shape educational programs to respond to the AI market requirements.

scholarly journals Material Geometry of Binary Composites

Symmetry ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 892
Author(s):  
Marcelo Epstein
Keyword(s):  
Continuum Mechanics ◽  
Mathematical Framework ◽  
Double Groupoid ◽  
The Individual ◽  
Elastic Composites

The constitutive characterization of the uniformity and homogeneity of binary elastic composites is presented in terms of a combination of the material groupoids of the individual constituents. The incorporation of these two groupoids within a single double groupoid is proposed as a viable mathematical framework for a unified formulation of this and similar kinds of problems in continuum mechanics.

scholarly journals Preclinical Testing of Radiopharmaceuticals for the Detection and Characterization of Osteomyelitis: Experiences from a Porcine Model

Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4221
Author(s):  
Aage Kristian Olsen Alstrup ◽  
Svend Borup Jensen ◽  
Ole Lerberg Nielsen ◽  
Lars Jødal ◽  
Pia Afzelius
Keyword(s):  
Animal Model ◽  
Animal Models ◽  
Porcine Model ◽  
Animal Experiments ◽  
Radioactive Tracers ◽  
The Individual ◽  
Selection Of

The development of new and better radioactive tracers capable of detecting and characterizing osteomyelitis is an ongoing process, mainly because available tracers lack selectivity towards osteomyelitis. An integrated part of developing new tracers is the performance of in vivo tests using appropriate animal models. The available animal models for osteomyelitis are also far from ideal. Therefore, developing improved animal osteomyelitis models is as important as developing new radioactive tracers. We recently published a review on radioactive tracers. In this review, we only present and discuss osteomyelitis models. Three ethical aspects (3R) are essential when exposing experimental animals to infections. Thus, we should perform experiments in vitro rather than in vivo (Replacement), use as few animals as possible (Reduction), and impose as little pain on the animal as possible (Refinement). The gain for humans should by far exceed the disadvantages for the individual experimental animal. To this end, the translational value of animal experiments is crucial. We therefore need a robust and well-characterized animal model to evaluate new osteomyelitis tracers to be sure that unpredicted variation in the animal model does not lead to a misinterpretation of the tracer behavior. In this review, we focus on how the development of radioactive tracers relies heavily on the selection of a reliable animal model, and we base the discussions on our own experience with a porcine model.

scholarly journals Molecular characterization of a beta zero-thalassemia resulting from a 1.4 kilobase deletion

Blood ◽  
1988 ◽  
Vol 72 (2) ◽  
pp. 636-641 ◽  
Author(s):  
R Anand ◽  
CD Boehm ◽  
HH Jr Kazazian ◽  
EF Vanin
Keyword(s):  
Transcriptional Start Site ◽  
Globin Gene ◽  
Event Analysis ◽  
Beta Globin ◽  
Base Pairs ◽  
Dna Polymerase Alpha ◽  
Beta Globin Gene ◽  
American Black ◽  
The Individual

Abstract We report the characterization of a beta zero-thalassemia in an American Black with unusually high HbA2 and HbF levels. Genomic southern analysis indicated that the individual was heterozygous for a deletion that began within the second intervening sequence of the beta- globin gene and extended approximately 1.4 kb in the 5′ direction. A clone spanning the breakpoint on the abnormal chromosome was isolated and further mapped, and the deletion joint was sequenced. Comparison of the normal beta-globin gene and its 5′ flanking region with the deletion joint sequence indicated that the 5′ breakpoint for this deletion was 484 base pairs (bp) 5′ to the transcriptional start site for the beta-globin gene and the 3′ breakpoint was 908 bp into the beta- globin gene; the deletion removed a total of 1,393 bp. Comparison of the normal 5′ and 3′ breakpoint sequences indicated that this deletion was the result of a “clean” nonhomologous breakage and reunion event; ie, no spurious bases were added during the recombinational event. Analysis of the breakpoints of this deletion together with the breakpoints of two other small deletions involving the beta-globin gene suggests that the breakpoints may occur at DNA polymerase alpha pause sites.

Sign in / Sign up

Export Citation Format

Share Document