Analysis of Grinding Temperature Considering Surface Generation Mechanism

2005 ◽  
Vol 291-292 ◽  
pp. 97-102 ◽  
Author(s):  
Toshiyuki Obikawa ◽  
J. Shinozuka
Keyword(s):  
Heat Flux ◽  
Cross Section ◽  
Heat Generation ◽  
Cross Sections ◽  
Surface Generation ◽  
Grinding Temperature ◽  
Geometrical Analysis ◽  
Heat Partition ◽  
Very High ◽  
Instantaneous Distribution

Grinding temperature was analyzed considering heat generation by cutting with each abrasive on the wheel working periphery. A geometrical analysis of interference between the abrasives and workpiece gave the instantaneous cutting cross section, and visualized the surface topography generated by the time. Using the specific grinding energy and the instantaneous cutting cross sections, the instantaneous distribution of heat generation on the wheel-workpiece contact area was obtained. Then grinding temperature was calculated for a given heat partition into the workpiece. Since a cutting with an abrasive generated an impulse of heat flux, temperature distribution calculated for grinding carbon tool steel varied drastically, and very high local temperature or temperature spikes appeared.

scholarly journals Production of radioisotopes within a plasma focus device

2005 ◽  
Vol 20 (1) ◽  
pp. 33-37 ◽  
Author(s):  
Ergisto Angeli ◽  
Agostino Tartari ◽  
Michele Frignani ◽  
Vincenzo Molinari ◽  
Domiziano Mostacci ◽  
...  
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Plasma Focus ◽  
Reaction Rates ◽  
Experimental Production ◽  
Endogenous Production ◽  
The Us ◽  
Further Development ◽  
Radio Isotopes ◽  
Very High

In recent years, research conducted in the US and in Italy has demonstrated production of radioisotopes in plasma focus devices, and particularly, on what could be termed "endogenous" production, to wit, production within the plasma it self, as opposed to irradiation of tar gets. This technique relies on the formation of localized small plasma zones characterized by very high densities and fairly high temperatures. The conditions prevailing in these zones lead to high nuclear reaction rates, as pointed out in previous work by several authors. Further investigation of the cross sections involved has proven necessary to model the phenomena involved. In this paper, the present status of research in this field is re viewed, both with regards to cross section models and to experimental production of radio isotopes. Possible out comes and further development are discussed.

Estimation of Nusselt Number in Microchannels of Arbitrary Cross-Section With Constant Axial Heat Flux

2008 ◽  
Author(s):  
Ehsan Sadeghi ◽  
Majid Bahrami ◽  
Ned Djilali
Keyword(s):  
Heat Flux ◽  
Nusselt Number ◽  
Cross Section ◽  
Cross Sections ◽  
Numerical Solutions ◽  
Arbitrary Cross Section ◽  
Geometrical Parameters ◽  
Thermal Systems ◽  
Cross Sectional ◽  
Axial Heat

In many practical instances such as basic design, parametric study, and optimization analysis of thermal systems, it is often very convenient to have closed form relations to obtain the trends and a reasonable estimate of the Nusselt number. However, finding exact solutions for many practical singly-connected cross-sections, such as trapezoidal microchannels, is complex. In the present study, the square root of cross-sectional area is proposed as the characteristic length scale for Nusselt number. Using analytical solutions of rectangular, elliptical, and triangular ducts, a compact model for estimation of Nusselt number of fully-developed, laminar flow in microchannels of arbitrary cross-sections with “H1” boundary condition (constant axial wall heat flux with constant peripheral wall temperature) is developed. The proposed model is only a function of geometrical parameters of the cross-section, i.e., area, perimeter, and polar moment of inertia. The present model is verified against analytical and numerical solutions for a wide variety of cross-sections with a maximum difference on the order of 9%.

scholarly journals Taming the Energy Rise of the Total Proton-Proton Cross-Section

Universe ◽  
2019 ◽  
Vol 5 (5) ◽  
pp. 106 ◽  
Author(s):  
Sergey Ostapchenko ◽  
Marcus Bleicher
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Strong Increase ◽  
Momentum Fraction ◽  
Proton Proton ◽  
High Energies ◽  
Model Predictions ◽  
Potential Impact ◽  
Very High

Steep rise of parton densities in the limit of small parton momentum fraction x poses a challenge for describing the observed energy-dependence of the total and inelastic proton-proton cross sections σ p p tot / inel : considering a realistic parton spatial distribution, one obtains a too-strong increase of σ p p tot / inel in the limit of very high energies. We discuss various mechanisms which allow one to tame such a rise, paying special attention to the role of parton-parton correlations. In addition, we investigate a potential impact on model predictions for σ p p tot, related to dynamical higher twist corrections to parton-production processes.

Conduction in Rings With Internal Heat Generation

2021 ◽  
Vol 143 (5) ◽  
Author(s):  
C. Y. Wang
Keyword(s):  
Cross Section ◽  
Heat Generation ◽  
Cross Sections ◽  
Rectangular Cross Section ◽  
Ritz Method ◽  
Circular Cross Section ◽  
Internal Heat ◽  
Internal Heat Generation ◽  
Convective Boundary ◽  
Steady State Heat

Abstract The basic problem of steady-state heat conduction in a ring with internal heat generation and convective boundary conditions is considered. An exact solution is found for the ring with a rectangular cross section and an efficient Ritz method is presented for general cross sections. The latter is applied to the torus or the ring with a circular cross section. Hot spots and cold spots are determined.

UNDERSTANDING THE NATURE OF PROTON–AIR CROSS-SECTIONS AT VERY HIGH ENERGIES AND THE IMPLICATIONS

2001 ◽  
Vol 16 (37) ◽  
pp. 2387-2397 ◽  
Author(s):  
BHASKAR DE ◽  
S. BHATTACHARYYA ◽  
P. GUPTAROY
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Cross Section Data ◽  
Section Data ◽  
High Energies ◽  
Production Models ◽  
Simulation Based ◽  
Effective Role ◽  
Very High

The purpose of this paper is to focus on the possible effective role of two relatively less-known models in analyzing comprehensively the very up-to-date data on proton–air inelastic cross-sections at high and ultra high energies. The standard versions of all the familiar simulation-based multiparticle production models, which nowadays normally claim front-ranking positions, address on the contrary, only a small part of the cross-section data for a very limited or sectional range of energy values. Against this background, the relevance and impact of the present study have finally been highlighted.

Plasmonic rod-in-shell nanoparticles for photothermal therapy

2014 ◽  
Vol 16 (24) ◽  
pp. 12275-12281 ◽  
Author(s):  
Shanshan Wang ◽  
Hong Xu ◽  
Jian Ye
Keyword(s):  
Optical Properties ◽  
Cross Section ◽  
Heat Generation ◽  
Cross Sections ◽  
Absorption Cross Section ◽  
Photothermal Therapy ◽  
Absorption Cross ◽  
Shell Nanoparticles ◽  
Tunable Absorption

The plasmonic rod-in-shell nanoparticles have a number of favorable optical properties for the photothermal therapy application compared to the nanorods: increased longitudinal and transversal absorption cross-sections in the NIR window I, a larger and highly tunable absorption cross-section in the NIR window II, orientation of particles insensitive to the heat generation.

Electron Irradiation Effects in Polyoxymethylene Crystals Grown Inside Trioxane Crystals

1971 ◽  
Vol 29 ◽  
pp. 78-79
Author(s):  
J. P. Colson ◽  
D. H. Reneker
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Detailed Examination ◽  
The Other ◽  
Electron Micrograph ◽  
Irradiation Effects ◽  
Threefold Axis ◽  
Typical Sample ◽  
Polymer Crystals ◽  
Chain Axis

Polyoxymethylene (POM) crystals grow inside trioxane crystals which have been irradiated and heated to a temperature slightly below their melting point. Figure 1 shows a low magnification electron micrograph of a group of such POM crystals. Detailed examination at higher magnification showed that three distinct types of POM crystals grew in a typical sample. The three types of POM crystals were distinguished by the direction that the polymer chain axis in each crystal made with respect to the threefold axis of the trioxane crystal. These polyoxymethylene crystals were described previously.At low magnifications the three types of polymer crystals appeared as slender rods. One type had a hexagonal cross section and the other two types had rectangular cross sections, that is, they were ribbonlike.

A quantitative approach to inner shell losses

1978 ◽  
Vol 36 (1) ◽  
pp. 526-527 ◽  
Author(s):  
R.D. Leapman ◽  
P. Rez ◽  
D.F. Mayers
Keyword(s):  
Energy Transfer ◽  
Cross Section ◽  
Cross Sections ◽  
Accurate Determination ◽  
Background Intensity ◽  
Core Excitation ◽  
Quantitative Basis ◽  
Cross Section Differential ◽  
Bound Electrons

Microanalysis by EELS has been developing rapidly and though the general form of the spectrum is now understood there is a need to put the technique on a more quantitative basis (1,2). Certain aspects important for microanalysis include: (i) accurate determination of the partial cross sections, σx(α,ΔE) for core excitation when scattering lies inside collection angle a and energy range ΔE above the edge, (ii) behavior of the background intensity due to excitation of less strongly bound electrons, necessary for extrapolation beneath the signal of interest, (iii) departures from the simple hydrogenic K-edge seen in L and M losses, effecting σx and complicating microanalysis. Such problems might be approached empirically but here we describe how computation can elucidate the spectrum shape.The inelastic cross section differential with respect to energy transfer E and momentum transfer q for electrons of energy E0 and velocity v can be written as

Oxygen K near edge structures studied with multiple scattering calculations

1988 ◽  
Vol 46 ◽  
pp. 504-505
Author(s):  
Xudong Weng ◽  
Peter Rez
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Partial Cross Section ◽  
Energy Window ◽  
Edge Structure ◽  
Fine Structures ◽  
Hydrogenic Model ◽  
Electron Energy Loss ◽  
Quantitative Chemical

In electron energy loss spectroscopy, quantitative chemical microanalysis is performed by comparison of the intensity under a specific inner shell edge with the corresponding partial cross section. There are two commonly used models for calculations of atomic partial cross sections, the hydrogenic model and the Hartree-Slater model. Partial cross sections could also be measured from standards of known compositions. These partial cross sections are complicated by variations in the edge shapes, such as the near edge structure (ELNES) and extended fine structures (ELEXFS). The role of these solid state effects in the partial cross sections, and the transferability of the partial cross sections from material to material, has yet to be fully explored. In this work, we consider the oxygen K edge in several oxides as oxygen is present in many materials. Since the energy window of interest is in the range of 20-100 eV, we limit ourselves to the near edge structures.

Absolute inner-shell cross section determination for EELS analysis

1988 ◽  
Vol 46 ◽  
pp. 534-535
Author(s):  
P.A. Crozier
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Absolute Cross Section ◽  
Specimen Thickness ◽  
Mass Thickness ◽  
Scattering Cross ◽  
Before And After ◽  
Estimated Error ◽  
Scattering Cross Sections ◽  
Electron Microscopist

Absolute inelastic scattering cross sections or mean free paths are often used in EELS analysis for determining elemental concentrations and specimen thickness. In most instances, theoretical values must be used because there have been few attempts to determine experimental scattering cross sections from solids under the conditions of interest to electron microscopist. In addition to providing data for spectral quantitation, absolute cross section measurements yields useful information on many of the approximations which are frequently involved in EELS analysis procedures. In this paper, experimental cross sections are presented for some inner-shell edges of Al, Cu, Ag and Au.Uniform thin films of the previously mentioned materials were prepared by vacuum evaporation onto microscope cover slips. The cover slips were weighed before and after evaporation to determine the mass thickness of the films. The estimated error in this method of determining mass thickness was ±7 x 107g/cm2. The films were floated off in water and mounted on Cu grids.

Sign in / Sign up

Export Citation Format

Share Document