Equilibrium or Nonequilibrium Models: A Critical Issue in Determination of Gas Diffusivity in Oil

2014 ◽  
Author(s):  
Hadi Saboorian-Jooybari ◽  
Morteza Dejam ◽  
Zhangxin John Chen
Keyword(s):  
Critical Issue ◽  
Gas Diffusivity ◽  
Nonequilibrium Models

Load Spectrum Compilation Based on Nonparametric Statistical Extrapolation

2013 ◽  
Vol 694-697 ◽  
pp. 271-277 ◽  
Author(s):  
Zhi Qiang Xu ◽  
Hong Jian Wang ◽  
Ming Yao Yao
Keyword(s):  
Kernel Function ◽  
Time History ◽  
Critical Issue ◽  
Extrapolation Method ◽  
Load History ◽  
Load Spectrum ◽  
Load Characteristics ◽  
Nonparametric Statistical ◽  
Function Shape

Considering the special load characteristics of the wheel loader, thispaper focus on compiling the load spectrum of the transmission of the wheelloader using the nonparametric statistical extrapolation method (NSEM). In thisprocess, the determination of the kernel function shape is the critical issue,which has been discussed in detail. Before extrapolating the sample loadspectrum, the signal denoising of the field-tested time-history load signals isperformed. After that, the sample load cycles are obtained using the rainflowcounting method and the corresponding kernel function shape is determined. Thenthe NSEM of rainflow matrix is proposed, by which the whole-life load spectrumis estimated. The proposed extrapolation method can well realize the estimationof the load cycles that do not appear in sample load cycles but may exist inthe whole-life load history.

Tensorial Deformation Measures for Flexible Joints

2010 ◽  
Vol 6 (3) ◽  
Author(s):  
Olivier A. Bauchau ◽  
Leihong Li ◽  
Pierangelo Masarati ◽  
Marco Morandini
Keyword(s):  
Finite Deformation ◽  
Nonlinear Behavior ◽  
Critical Issue ◽  
Finite Deformations ◽  
Flexible Joints ◽  
Elastic Bodies ◽  
Infinitesimal Deformations ◽  
Stiffness Characteristics ◽  
Definition Of

Flexible joints, sometimes called bushing elements or force elements, are found in all multibody dynamics codes. In their simplest form, flexible joints simply consist of sets of three linear and three torsional springs placed between two nodes of a multibody system. For infinitesimal deformations, the selection of the lumped spring constants is an easy task, which can be based on a numerical simulation of the joint or on experimental measurements. If the joint undergoes finite deformations, the identification of its stiffness characteristics is not so simple, especially if the joint itself is a complex system. When finite deformations occur, the definition of deformation measures becomes a critical issue. Indeed, for finite deformation, the observed nonlinear behavior of materials is partly due to material characteristics and partly due to kinematics. This paper focuses on the determination of the proper finite deformation measures for elastic bodies of finite dimension. In contrast, classical strain measures, such as the Green–Lagrange or Almansi strains, among many others, characterize finite deformations of infinitesimal elements of a body. It is argued that proper finite deformation measures must be of a tensorial nature, i.e., must present specific invariance characteristics. This requirement is satisfied if and only if the deformation measures are parallel to the eigenvector of the motion tensor.

Determination of carbapenemase genes in clinical isolates using Cepheid Xpert Carba-R

2021 ◽  
pp. 16-19
Author(s):  
N. I. Gabrielyan ◽  
V. G. Kormilitsyna ◽  
V. K. Zaletaeva ◽  
A. V. Krotevich ◽  
I. A. Miloserdov ◽  
...  
Keyword(s):  
Targeted Therapy ◽  
Infection Control ◽  
Resistance Genes ◽  
Carbapenem Resistance ◽  
Critical Issue ◽  
Sensitivity Study ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Carbapenem Resistant

Detection of carbapenem resistance genes is a critical issue for hospitals due to possible recommendations for infection control and targeted therapy. The Cepheid Xpert instrument, a Carba-R test for the detection and differentiation of five common carbapenemase genes, was tested from September 2020 to February 2021. As part of the approbation, 20 tests were provided. This review presents the results of the approbation of a relatively regular sensitivity study on Siemens WalkAway‑96 plus. Cepheid Xpert Carba-R analysis has been shown to be an accurate and fast tool for detecting colonization by carbapenem-resistant gram-negative bacteria, which can help limit the spread of these organisms in hospitals.

scholarly journals Abundance variations of tracers and their effects on our determination of molecular cloud structure

1991 ◽  
Vol 147 ◽  
pp. 177-181
Author(s):  
Paul F. Goldsmith
Keyword(s):  
Molecular Cloud ◽  
Molecular Clouds ◽  
Column Density ◽  
Critical Issue ◽  
Structure Stability ◽  
Molecular Gas ◽  
Cloud Structure ◽  
Molecular Tracer ◽  
Short Presentation

Our understanding of the molecular phase of the interstellar medium is critically dependent on use of various lines from different molecular species to trace this dense material. As our knowledge of molecular clouds becomes more refined, and we pursue in detail issues of molecular cloud structure, stability, and how star formation depends on and affects the molecular gas, it is appropriate to examine the basis by which we determine the morphology of clouds, their density, and other key parameters. This is obviously a major undertaking, well beyond the scope of the short presentation at this conference, so I will concentrate on one very basic, but critical issue, which is that of abundance variations of tracers of density and molecular column density which are widely used to delineate the denser portions of all types of molecular clouds. In this summary, I will first highlight some of the apparent indications of significant variations of abundance within individual clouds, as a way of indicating some potential dangers and the importance of the molecular tracer selected. I will also briefly suggest how such variations may be themselves important diagnostics of cloud structure and evolution.

Brain Death?

PEDIATRICS ◽  
1987 ◽  
Vol 79 (6) ◽  
pp. 1057-1057
Author(s):  
JEFFREY P. MORRAY ◽  
ELLIOT J. KRANE ◽  
ANNE M. LYNN ◽  
DONALD C. TYLER
Keyword(s):  
Brain Death ◽  
Critical Issue ◽  
Recent Experience ◽  
Diagnosis Of Death

To the Editor.— Because we are now able to provide long-term cardio-pulmonary support, the determination of cerebral death in children is a critical issue, both to provide an unambiguous diagnosis of death and, when appropriate, to allow recovery of organs for transplantation. Perhaps this latter issue provided the impetus for Drake et al1 to evaluate their recent experience at Loma Linda and to present a protocol for the determination of brain death in children.

Determination of Particle Penetration Factors in a Particle Transfer Line for Aero Gas Turbine Engine Exhaust Particle Measurement

2014 ◽  
Author(s):  
Mohamed A. Altaher ◽  
Hu Li ◽  
Paul Williams ◽  
Mark Johnson ◽  
Simon Blakey
Keyword(s):  
Critical Issue ◽  
Aircraft Engines ◽  
Measurement Instruments ◽  
Engine Exhaust ◽  
Particle Emissions ◽  
Reliable Determination ◽  
Particle Penetration ◽  
Transfer Line ◽  
Particle Measurement

There is a need to develop a reliable and standard PM (Particulate Matter) measurement method for aircraft engines. Due to safety and practicability of such measurements, a distance is required for the transportation of the exhaust samples from the aircraft engine exhaust exit to particle measurement instruments. The particle line loss during the transportation is therefore a critical issue for the accurate and reliable determination of particle emissions from aircraft engines. The work in this paper investigated the particle penetration/loss along a 25 meters ARP proposed particle sample transfer line by measuring the particle emissions from an aircraft auxiliary power unit (APU) at idle and full power. Two SMPS instruments were used to simultaneously measure exhaust particle size distributions at the entrance and exit of the 25 m transfer line. A catalytic stripper was used to remove volatile particles so that non-volatile particles can be measured. The particle penetration factors for the 25 m transfer line were found to be 0.6∼0.7 in general, excluding particles smaller than 10 nm. For the particles smaller than 10nm, particle penetrations were very poor and about 70–100% of parcel losses were observed. The volatile factions were roughly 20∼30% of the total concentrations.

scholarly journals Abundance variations of tracers and their effects on our determination of molecular cloud structure

1991 ◽  
Vol 147 ◽  
pp. 177-181
Author(s):  
Paul F. Goldsmith
Keyword(s):  
Molecular Cloud ◽  
Molecular Clouds ◽  
Column Density ◽  
Critical Issue ◽  
Structure Stability ◽  
Molecular Gas ◽  
Cloud Structure ◽  
Molecular Tracer ◽  
Short Presentation

Our understanding of the molecular phase of the interstellar medium is critically dependent on use of various lines from different molecular species to trace this dense material. As our knowledge of molecular clouds becomes more refined, and we pursue in detail issues of molecular cloud structure, stability, and how star formation depends on and affects the molecular gas, it is appropriate to examine the basis by which we determine the morphology of clouds, their density, and other key parameters. This is obviously a major undertaking, well beyond the scope of the short presentation at this conference, so I will concentrate on one very basic, but critical issue, which is that of abundance variations of tracers of density and molecular column density which are widely used to delineate the denser portions of all types of molecular clouds. In this summary, I will first highlight some of the apparent indications of significant variations of abundance within individual clouds, as a way of indicating some potential dangers and the importance of the molecular tracer selected. I will also briefly suggest how such variations may be themselves important diagnostics of cloud structure and evolution.

scholarly journals PLANE-BASED REGISTRATION OF SEVERAL THOUSAND LASER SCANS ON STANDARD HARDWARE

2018 ◽  
Vol XLII-2 ◽  
pp. 1207-1212 ◽  
Author(s):  
D. Wujanz ◽  
S. Schaller ◽  
F. Gielsdorf ◽  
L. Gründig
Keyword(s):  
Memory Management ◽  
Critical Issue ◽  
Automatic Registration ◽  
Topological Relations ◽  
Town Hall ◽  
Registration Procedure ◽  
Stochastic Characteristics ◽  
Pairwise Registration

The automatic registration of terrestrial laser scans appears to be a solved problem in science as well as in practice. However, this assumption is questionable especially in the context of large projects where an object of interest is described by several thousand scans. A critical issue inherently linked to this task is memory management especially if cloud-based registration approaches such as the ICP are being deployed. In order to process even thousands of scans on standard hardware a plane-based registration approach is applied. As a first step planar features are detected within the unregistered scans. This step drastically reduces the amount of data that has to be handled by the hardware. After determination of corresponding planar features a pairwise registration procedure is initiated based on a graph that represents topological relations among all scans. For every feature individual stochastic characteristics are computed that are consequently carried through the algorithm. Finally, a block adjustment is carried out that minimises the residuals between redundantly captured areas. The algorithm is demonstrated on a practical survey campaign featuring a historic town hall. In total, 4853 scans were registered on a standard PC with four processors (3.07 GHz) and 12 GB of RAM.

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