Pixe Spectrometry as an Aid to Reconstruction of Ancient Processes of Bronze Production

1988 ◽  
Vol 123 ◽  
Author(s):  
C.P. Swann ◽  
S.J. Fleming
Keyword(s):  
High Temperature ◽  
Thermodynamic Properties ◽  
Qualitative Description ◽  
Copper Ore ◽  
Full Characterization ◽  
Definition Of ◽  
Metal Microstructure ◽  
Analytical Tools ◽  
By Products

The process of translating copper ore into a finished bronze involved a series of discrete steps (Fig. 1), the products and by-products of which comprise a diversity of materials. The full characterization of these materials, and thereby the reconstruction of how the metalworking artisans of a particular culture went about their craft, requires a variety of analytical tools, each applied with specific interpretive goals in mind. For example, the use of high power optical microscopy (with magnifications ranging 10x to 400x) allows a qualitative description of ore and slag petrography [1], and the definition of individual phases in metal microstructure (see, for example, refs. [2,3]); the use of high temperature cell (HTC) microscopy, offers a novel means of studying a slag's thermodynamic properties [4]; and so on.

High Temperature (230 °C) Isolated Power Supply

2010 ◽  
Vol 2010 (HITEC) ◽  
pp. 000283-000288 ◽  
Author(s):  
B. Reese ◽  
R. Shaw ◽  
J. Hornberger ◽  
R. Schupbach ◽  
A. Lostetter
Keyword(s):  
High Temperature ◽  
Power Supply ◽  
Single Layer ◽  
Thermal Design ◽  
Silicon On Insulator ◽  
Full Characterization ◽  
Soft Start ◽  
Power Switches ◽  
Layer Control

This paper discusses the development of a high temperature (i.e., 230 °C ambient) 100V–300V/15V 20W isolated power supply. The power supply is implemented using Silicon-Carbide (SiC) power switches, high-temperature silicon on insulator (HTSOI) control circuitry, as well as custom high temperature magnetics and packaging technology. The heart of this power supply is a custom-built PWM controller. The controller was built utilizing HTSOI component, which operate at temperatures as high as 300 °C. The developed power supply targets high ambient temperature environment applications and includes features such as housekeeping power supply, soft-start and under-voltage lockout. The power supply is packaged using a multi-chip module (MCM) packaging approach. A single layer power substrate and a multiple layer control substrate are used. Bare die devices are utilized to save space, reduce parasitic impedances, and increase temperature of operation and reliability. This paper provides details on the electrical and thermal design as well as fabrication and characterization of the power supply. Additionally, results of the full characterization of this power supply are provided; this includes temperature testing up to 230 °C, efficiency results, load transition behavior, output ripple, etc.

scholarly journals Synthesis of low immunogenicity RNA with high-temperature in vitro transcription

2019 ◽  
Author(s):  
Monica Z. Wu ◽  
Haruichi Asahara ◽  
George Tzertzinis ◽  
Bijoyita Roy
Keyword(s):  
High Temperature ◽  
In Vitro Transcription ◽  
Synthesis Process ◽  
Run Off ◽  
Post Synthesis ◽  
Cellular Immune ◽  
By Products

ABSTRACTThe use of synthetic RNA for therapeutics requires that the in vitro synthesis process be robust and efficient. The technology used for the synthesis of these in vitro-transcribed mRNAs, predominantly using phage RNA polymerases (RNAPs), is well established. However, transcripts synthesized with RNAPs are known to display an immune-stimulatory activity in vivo, that is often undesirable. Previous studies have identified double-stranded RNA (dsRNA), a major by-product of the in vitro transcription (IVT) process, as a trigger of cellular immune responses. Here we describe the characterization of a high-temperature IVT process using thermostable T7 RNAPs to synthesize functional mRNAs that demonstrate reduced immunogenicity without the need for a post-synthesis purification step. We identify features that drive the production of two kinds of dsRNA by-products—one arising from 3’ extension of the run-off product and one formed by the production of antisense RNAs—and demonstrate that at a high temperature, T7 RNAP has reduced 3’-self extension of the run-off product. We show that template-encoded poly-A tailing does not affect 3’-self extension but reduces the formation of the antisense RNA by-products and that combining high-temperature IVT with template-encoded poly-A tailing prevents formation of both kinds of by-products.

scholarly journals METRIC AND TOPOLOGICAL FREEDOM FOR SEQUENTIAL OPERATOR SPACES

2017 ◽  
Vol 20 (10) ◽  
pp. 55-67
Author(s):  
N.T. Nemesh ◽  
S.M. Shteiner
Keyword(s):  
Duality Theory ◽  
Operator Space ◽  
Space Theory ◽  
Operator Spaces ◽  
Normed Spaces ◽  
Full Characterization ◽  
Definition Of ◽  
Phd Thesis ◽  
Space Homology

In 2002 Anselm Lambert in his PhD thesis [1] introduced the definition of sequential operator space and managed to establish a considerable amount of analogs of corresponding results in operator space theory. Informally speaking, the category of sequential operator spaces is situated ”between” the categories of normed and operator spaces. This article aims to describe free and cofree objects for different versions of sequential operator space homology. First of all, we will show that duality theory in above-mentioned category is in many respects analogous to that in the category of normed spaces. Then, based on those results, we will give a full characterization of both metric and topological free and cofree objects.

scholarly journals On Application of Hyperfree Energy for the Description of Thermodynamics of Mobile Components in Nonstoichiometric Partially Open Ceramic Systems

2020 ◽  
Author(s):  
Jaroslav Šesták
Keyword(s):  
High Temperature ◽  
Solid State ◽  
Thermodynamic Functions ◽  
Energy Function ◽  
Initial Phase ◽  
Open Systems ◽  
Superconducting Materials ◽  
Mobile Component ◽  
Definition Of

Nonstoichiometric oxides form a new chapter in tailored materials. Founding and construction of thermodynamic functions related to solid (geologic, metallurgic) materials is traced showing interactions between Czech Professor F. Wald and Russians R.S. Kurnakov and D.S. Korzhinskiĭ and further developed by Czech P. Holba in the initial phase definition and related characterization of partially open systems. A gradual increase in thermodynamic concepts related to solid-state description is investigated in more detail. For the associated thermodynamic definition of the mobile component, the previously formulated hyperfree energy function, which was recently applied to several systems, was used. As a measure of the material disposition for the absorption of the free component, an innovative term of plutability is proposed, which allows the introduction of various forecaster variables such as temperature, pressure, and activity. Examples of practical application are examples of high-temperature superconducting materials, where the Czech school of thermodynamics is emphasized.

Complete High Dimensional Inverse Characterization of Fractal Surfaces

2011 ◽  
Author(s):  
John G. Michopoulos ◽  
Athanasios Iliopoulos
Keyword(s):  
High Dimensional ◽  
Additional Parameter ◽  
The Road ◽  
Full Characterization ◽  
Elevation Data ◽  
Deformable Materials ◽  
Definition Of ◽  
Value Decomposition

The present paper describes a methodology for the inverse identification of the complete set of parameters associated with the Weirstrass-Mandelbrot (W-M) function that can describe any rough surface known by its profilometric or topographic data. Our effort is motivated by the need to determine the mechanical, electrical and thermal properties of contact surfaces between deformable materials that conduct electricity and heat and require an analytical representation of the surfaces involved. Our method involves utilizing a refactoring of the W-M function that permits defining the characterization problem as a high dimensional singular value decomposition problem for the determination of the so-called phases of the function. Coupled with this process is a second level exhaustive search that enables the determination of the density of the frequencies involved in defining the trigonometric functions involved in the definition of the W-M function. Our approach proves that this is the only additional parameter that needs to be determined for full characterization of the W-M function as the rest can be selected arbitrarily. Numerical applications of the proposed method on both synthetic and actual elevation data, validate the efficiency and the accuracy of the proposed approach. This approach constitutes a radical departure from the traditional fractal dimension characterization studies and opens the road for a very large number of applications.

A Thorough Theoretical Exploration of Intriguing Characteristics of Cyclo[18]carbon: Geometry, Bonding Nature, Aromaticity, Weak Interaction, Reactivity, Excited States, Vibrations, Molecular Dynamics and Various Molecular Properties

2019 ◽  
Author(s):  
Tian Lu ◽  
Qinxue Chen ◽  
Zeyu Liu
Keyword(s):  
Molecular Dynamics ◽  
Excited States ◽  
Electronic Excitation ◽  
Ring Structure ◽  
Molecular Properties ◽  
Molecular Vibration ◽  
Full Characterization ◽  
Long Time ◽  
Almost All

Although cyclo[18]carbon has been theoretically and experimentally investigated since long time ago, only very recently it was prepared and directly observed by means of STM/AFM in condensed phase (Kaiser et al., <i>Science</i>, <b>365</b>, 1299 (2019)). The unique ring structure and dual 18-center π delocalization feature bring a variety of unusual characteristics and properties to the cyclo[18]carbon, which are quite worth to be explored. In this work, we present an extremely comprehensive and detailed investigation on almost all aspects of the cyclo[18]carbon, including (1) Geometric characteristics (2) Bonding nature (3) Electron delocalization and aromaticity (4) Intermolecular interaction (5) Reactivity (6) Electronic excitation and UV/Vis spectrum (7) Molecular vibration and IR/Raman spectrum (8) Molecular dynamics (9) Response to external field (10) Electron ionization, affinity and accompanied process (11) Various molecular properties. We believe that our full characterization of the cyclo[18]carbon will greatly deepen researchers' understanding of this system, and thereby help them to utilize it in practice and design its various valuable derivatives.

A Thorough Theoretical Exploration of Intriguing Characteristics of Cyclo[18]carbon: Geometry, Bonding Nature, Aromaticity, Weak Interaction, Reactivity, Excited States, Vibrations, Molecular Dynamics and Various Molecular Properties

2019 ◽  
Author(s):  
Tian Lu ◽  
Qinxue Chen ◽  
Zeyu Liu
Keyword(s):  
Molecular Dynamics ◽  
Excited States ◽  
Electronic Excitation ◽  
Ring Structure ◽  
Molecular Properties ◽  
Molecular Vibration ◽  
Full Characterization ◽  
Long Time ◽  
Almost All

Although cyclo[18]carbon has been theoretically and experimentally investigated since long time ago, only very recently it was prepared and directly observed by means of STM/AFM in condensed phase (Kaiser et al., <i>Science</i>, <b>365</b>, 1299 (2019)). The unique ring structure and dual 18-center π delocalization feature bring a variety of unusual characteristics and properties to the cyclo[18]carbon, which are quite worth to be explored. In this work, we present an extremely comprehensive and detailed investigation on almost all aspects of the cyclo[18]carbon, including (1) Geometric characteristics (2) Bonding nature (3) Electron delocalization and aromaticity (4) Intermolecular interaction (5) Reactivity (6) Electronic excitation and UV/Vis spectrum (7) Molecular vibration and IR/Raman spectrum (8) Molecular dynamics (9) Response to external field (10) Electron ionization, affinity and accompanied process (11) Various molecular properties. We believe that our full characterization of the cyclo[18]carbon will greatly deepen researchers' understanding of this system, and thereby help them to utilize it in practice and design its various valuable derivatives.

RHEOLOGICAL CHARACTERIZATION OF PERUVIAN COPPER ORE SLURRIES

2020 ◽  
Author(s):  
Joel López Bonilla ◽  
Cesar Celis ◽  
Danmer Maza
Keyword(s):  
Rheological Characterization ◽  
Copper Ore
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