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161.
This paper describes a methodology for measuring rheological flow properties in-line, in real-time, based on simultaneous measurements of velocity profiles using an ultrasound velocity profiling (UVP) technique with pressure difference (PD) technology. The methodology allows measurements that are rapid, non-destructive and non-invasive and has several advantages over methods presented previously. The set-up used here allows direct access to demodulated echo amplitude data, thus providing an option to switch between time domain algorithms and algorithms based on FFT for estimating velocities, depending on the signal-to-noise ratio (SNR) and time resolution required. Software based on the MATLAB® graphical user interface (GUI) has been developed and provides a powerful and rapid tool for visualizing and processing the data acquired, giving rheological information in real-time and in excellent agreement with conventional methods. This paper further focuses on crucial aspects of the methodology: implementation of low-pass filter and singular value decomposition (SVD) methods, non-invasive measurements and determination of the wall positions using channel correlation and methods based on SVD. Measurements of sound velocity and attenuation of ultrasound in-line were introduced to increase measurement accuracy and provide an interesting approach to determine particle concentration in-line. The UVP-PD methodology presented may serve as an in-line tool for non-invasive, real-time monitoring and process control. 相似文献
162.
Ronald J. Gelten Tonek P.J. Jansen Rutger A. van Santen Johan J. Lukkien John P.L. Segers Peter A.J. Hilbers 《Israel journal of chemistry》1998,38(4):415-428
The dynamic Monte Carlo method has been used to simulate the 2 A + B2 → 2 AB reaction catalyzed by a reconstructing substrate. Oscillatory behavior and spatio-temporal is studied as a function of grid size. Spatio-temporal pattern formation has been simulated in various forms: cellular patterns, target patterns, rotating spirals, and turbulent patterns. Cellular patterns are a manifestation of a local synchronization mechanism in which all reaction fronts periodically extinguish each other. This illustrates that dynamic Monte Carlo simulations form a promising technique and can be used to predict macroscopic kinetic phenomena on a molecular basis. 相似文献
163.
Oldehinkel Albertine J.; Ormel Johan; Neeleman Jan 《Canadian Metallurgical Quarterly》2000,109(2):299
The authors examined the role of personality, social support, and coping strategies and their interaction with positive life change (PLC) in influencing time to remission from depression in 86 depressed primary care patients (69% women, mean age?=?36.6 years), who were followed for 3.5 years. Diagnostic information was obtained by the Present State Examination (J. K. Wing, J. Cooper, & N. Sartorius, 1974), and life change by the Life Events and Difficulties Schedule (G. W. Brown & T. 0. Harris, 1978). The association of PLC and other predictors with the time to remission was studied by means of Cox regression. PLC reduced time to remission in women, but not in men. Other predictors that expedited remission were low severity of premorbid difficulties, high self-esteem and a tension-reducing coping style. Neuroticism modified the effect of PLC in that the remission forward bringing effect of PLC was stronger for highly neurotic people. The results suggest that women and psychologically vulnerable persons benefit most from PLC. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
164.
Bolhuis Johan; Johnson Mark; Horn Gabriel; Bateson Patrick 《Canadian Metallurgical Quarterly》1989,103(2):438
Imprinting leads to strong filial attachment to the mother. Later it influences mate choice. Although nothing is known about the brain regions involved in adult sexual preferences, a particular region of the domestic chick's forebrain (IMHV) has been implicated in filial imprinting. In the present experiment lesions were placed in this region of female chicks soon after hatching. When these and control birds were adult, their sexual preferences were tested. The sham-operated control females had preferences for a male that differed slightly from one with which they had been reared. In contrast, females with lesions did not show a clear preference. It is suggested that the lesion impairs filial and sexual imprinting by disrupting the ability of chicks to learn the characteristics of individuals. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
165.
Simon M. M. Pedersen Caroline Nebel Niels Chr. Nielsen Henrik J. Andersen Johan Olsson Magnus Simrén Lena Öhman Ulla Svensson Hanne C. Bertram Anders Malmendal 《European Food Research and Technology》2011,233(6):1013-1021
In the present study, the use of gas chromatography mass spectrometry (GC–MS)-based metabonomics to characterize blood serum
in an intervention study of patients suffering from the common gastrointestinal disorder irritable bowel syndrome (IBS) was
investigated. The patients included in the study consumed an acidified milk product with (n = 30) or without probiotics (n = 31) (Lactobacillus paracasei F19, Lactobacillus acidophilus LA-5 and Bifidobacterium lactis BB-12) for an 8-week period, and blood serum samples were collected before and after the intervention. Acidified milk is
commonly used as a delivering vector for probiotics in commercial consumer settings. The serum samples were extracted and
derivatized using N-Methyl-N-(trimethylsilyl) trifluoroacetamide (MSTFA), and GC–MS analysis was carried out. Multivariate data analysis including principal
component analysis (PCA), orthogonal partial least squares-discriminant analysis (OPLS-DA), and S-plot was applied on the
obtained GC–MS data, which revealed higher serum lactate, glutamine, proline creatinine/creatine, and aspartic acid levels
and lower serum glucose levels after the intervention period for both treatment groups. Consequently, the present study indicated
an effect of acidified milk consumption on the plasma metabolite profile, which was independent of a concomitant intake of
probiotics. In addition, the present study demonstrates that GC–MS is a useful analytical technique for metabonomics studies
of blood serum. 相似文献
166.
The load sharing between phases and the evolution of micro- and macrostresses during cyclic loading has been investigated
in a 1.5-mm cold-rolled sheet of the duplex stainless steel SAF 2304. X-ray diffraction (XRD) stress analysis and transmission
electron microscopy (TEM) show that even if the hardness and yield strength are higher in the austenitic phase, more plastic
deformation will occur in this phase due to the residual microstresses present in the material. The origin of the microstresses
is the difference in coefficients of thermal expansion between the two phases, which leads to tensile microstresses in the
austenite and compressive microstresses in the ferrite. The microstresses were also found to increase from 50 to 140 MPa in
the austenite during the first 100 cycles when cycled in tension fatigue with a maximum load of 500 MPa. The cyclic loading
response of the material was, thus, mainly controlled by the plastic properties of the austenitic phase. It was also found
that initial compressive macrostresses on the surface increased from −40 to 50 MPa during the first 103 cycles. After the initial increase of microstresses and macrostresses, no fading of residual stresses was found to occur
for the following cycles. A good correlation was found between the internal stress state and the microstructure evolution.
The change in texture during cyclic fatigue showed a sharpening of the deformation texture in the ferritic phase, while no
significant changes were found in the austenitic phase. 相似文献
167.
Juan M. Garcés Michael M. Olken G. John Lee Garry R. Meima Pierre A. Jacobs Johan A. Martens 《Topics in Catalysis》2009,52(9):1175-1181
This is a review of work carried at Dow Chemical on the design and characterization of novel mordenite catalysts with a unique
micro and meso-porous structure characterized by a variety of methods including, TEM, BET surface area and pore size distribution,
and n-decane hydro-conversion. The catalytic performance of these catalysts in shape selective reactions is illustrated with results
from n-decane hydro-conversion and applications to alkylation and trans-alkylation reactions of mono and polynuclear aromatic hydrocarbons and other chemistries.
Juan M. Garcés and G. John Lee both retired from The Dow Chemical Company. 相似文献
168.
Overview of the MPEG Reconfigurable Video Coding Framework 总被引:2,自引:0,他引:2
Shuvra S. Bhattacharyya Johan Eker Jörn W. Janneck Christophe Lucarz Marco Mattavelli Mickaël Raulet 《Journal of Signal Processing Systems》2011,63(2):251-263
Video coding technology in the last 20 years has evolved producing a variety of different and complex algorithms and coding
standards. So far the specification of such standards, and of the algorithms that build them, has been done case by case providing
monolithic textual and reference software specifications in different forms and programming languages. However, very little
attention has been given to provide a specification formalism that explicitly presents common components between standards,
and the incremental modifications of such monolithic standards. The MPEG Reconfigurable Video Coding (RVC) framework is a
new ISO standard currently under its final stage of standardization, aiming at providing video codec specifications at the
level of library components instead of monolithic algorithms. The new concept is to be able to specify a decoder of an existing
standard or a completely new configuration that may better satisfy application-specific constraints by selecting standard
components from a library of standard coding algorithms. The possibility of dynamic configuration and reconfiguration of codecs
also requires new methodologies and new tools for describing the new bitstream syntaxes and the parsers of such new codecs.
The RVC framework is based on the usage of a new actor/ dataflow oriented language called CAL for the specification of the standard library and instantiation of the RVC decoder model. This language has been specifically
designed for modeling complex signal processing systems. CAL dataflow models expose the intrinsic concurrency of the algorithms by employing the notions of actor programming and dataflow.
The paper gives an overview of the concepts and technologies building the standard RVC framework and the non standard tools
supporting the RVC model from the instantiation and simulation of the CAL model to software and/or hardware code synthesis. 相似文献
169.
170.