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61.
Odilia I Bermudez Claire Toher Gabriela Montenegro-Bethancourt Marieke Vossenaar Paul Mathias Colleen Doak Noel W Solomons 《Nutrition journal》2010,9(1):20
Background
Consumption of healthy diets that contribute with adequate amounts of fat and fatty acids is needed for children. Among Guatemalan children, there is little information about fat intakes. Therefore, the present study sought to assess intakes of dietary fats and examine food sources of those fats in Guatemalan children. 相似文献62.
Dilip K. De Nathaniel Muwa Shawhatsu Narendra Nath De Mathias Ikechukwu Ajaeroh 《Energy Efficiency》2013,6(1):163-175
Energy-efficient new cooking techniques have been developed in this research. Using a stove with 649?±?20 W of power, the minimum heat, specific heat of transformation, and on-stove time required to completely cook 1 kg of dry beans (with water and other ingredients) and 1 kg of raw potato are found to be: 710 (±24)?kJ, 613 (±20)?kJ, and 1,144?±?10 s, respectively, for beans and 287?±?12 kJ, 200?±?9 kJ, and 466?±?10 s for Irish potato. Extensive researches show that these figures are, to date, the lowest amount of heat ever used to cook beans and potato and less than half the energy used in conventional cooking with a pressure cooker. The efficiency of the stove was estimated to be 52.5?±?2 %. Discussion is made to further improve the efficiency in cooking with normal stove and solar cooker and to save food nutrients further. Our method of cooking when applied globally is expected to contribute to the clean development management (CDM) potential. The approximate values of the minimum and maximum CDM potentials are estimated to be 7.5?×?1011 and 2.2?×?1013?kg of carbon credit annually. The precise estimation CDM potential of our cooking method will be reported later. 相似文献
63.
Jean-Denis Mathias Pierre-Marie Geffroy Jean-François Silvain 《Applied Thermal Engineering》2009,29(11-12):2391-2395
The aim of this paper is to provide a methodical approach for architectural optimization of power microelectronic devices. Because critical parameters of electronic devices are linked with reliability, architectural optimization, selection of the geometrical parameters of device and optimization of these parameters by iteration method associated by numerical analysis of reliability have to be achieved. In this way, this paper discusses about a methodical and numerical approach for the optimization of reliability in electronic devices, in particular the influence of geometrical parameters on the device reliability. 相似文献
64.
Mathias Dietrich Guillaume Delaittre James P. Blinco Andrew J. Inglis Michael Bruns Christopher Barner‐Kowollik 《Advanced functional materials》2012,22(2):304-312
The nitrile imine‐mediated tetrazole‐ene cycloaddition reaction (NITEC) is introduced as a powerful and versatile conjugation tool to covalently ligate macromolecules onto variable (bio)surfaces. The NITEC approach is initiated by UV irradiation and proceeds rapidly at ambient temperature yielding a highly fluorescent linkage. Initially, the formation of block copolymers by the NITEC methodology is studied to evidence its efficacy as a macromolecular conjugation tool. The grafting of polymers onto inorganic (silicon) and bioorganic (cellulose) surfaces is subsequently carried out employing the optimized reaction conditions obtained from the macromolecular ligation experiments and evidenced by surface characterization techniques, including X‐ray photoelectron spectroscopy and FT‐IR microscopy. In addition, the patterned immobilization of variable polymer chains onto profluorescent cellulose is achieved through a simple masking process during the irradiation. 相似文献
65.
Ultrafast compound imaging for 2-D motion vector estimation: application to transient elastography 总被引:1,自引:0,他引:1
Tanter M Bercoff J Sandrin L Fink M 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》2002,49(10):1363-1374
This paper describes a new technique for two-dimensional (2-D) imaging of the motion vector at a very high frame rate with ultrasound. Its potential is experimentally demonstrated for transient elastography. But, beyond this application, it also could be promising for color flow and reflectivity imaging. To date, only axial displacements induced in human tissues by low-frequency vibrators were measured during transient elastography. The proposed technique allows us to follow both axial and lateral displacements during the shear wave propagation and thus should improve Young's modulus image reconstruction. The process is a combination of several ideas well-known in ultrasonic imaging: ultra-fast imaging, multisynthetic aperture beamforming, 1-D speckle tracking, and compound imaging. Classical beamforming in the transmit mode is replaced here by a single plane wave insonification increasing the frame rate by at least a factor of 128. The beamforming is achieved only in the receive mode on two independent subapertures. Comparison of successive frames by a classical 1-D speckle tracking algorithm allows estimation of displacements along two different directions linked to the subapertures beams. The variance of the estimates is finally improved by tilting the emitting plane wave at each insonification, thus allowing reception of successive decorrelated speckle patterns. 相似文献
66.
Blom H Johansson M Gösch M Sigmundsson T Holm J Hård S Rigler R 《Applied optics》2002,41(31):6614-6620
We have developed a multifocal optical fluorescence correlation spectroscopy system for parallel flow analyses. Multifocal excitation was made possible through a 4 x 1 diffractive optical fan-out element, which produces uniform intensity in all four foci. Autocorrelation flow analyses inside a 20 microm x 20 microm square microchannel, with the 4 x 1 fan-out foci perpendicular to the flow direction, made it possible to monitor different flows in all four foci simultaneously. We were able to perform cross-correlation flow analyses by turning the microstructure, thereby having all four foci parallel to the direction of flow. Transport effects of the diffusion as a function of flow and distance could then also be studied. 相似文献
67.
68.
The influence of short wavelength light on the characteristic bulk minority carrier diffusion length of the ribbon silicon photovoltaic cell has been investigated. We have measured the intensity and wavelength dependence of the diffusion length in an EFG ribbon cell, and compared it with a standard Czochralski grown silicon cell. While the various short wavelength illuminations have shown no influence on the diffusion length in the CZ cell, the diffusion lengths in the ribbon cell exhibit a strong dependence on the volume generate rate as well as on the wavelength of the superimposed lights. We have concluded that the trap-filling phenomenon at various depths in the bulk neutral region of the cell is consistent with the experimental observation. 相似文献
69.
Gennisson JL Baldeweck T Tanter M Catheline S Fink M Sandrin L Cornillon C Querleux B 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》2004,51(8):980-989
Sonoelastography and transient elastography are two ultrasound-based techniques that facilitate noninvasive characterization of the viscoelastic properties of soft tissues by investigating their response to shear mechanical excitation. Young's modulus is the principle assessment parameter. Because it defines local tissue stiffness, it is of major interest for the medical imaging and cosmetic industries as it could replace subjective palpation by yielding local, quantitative information. In this paper, we describe a new high-resolution device capable of measuring local Young's modulus in very thin layers (1-5 mm) and devoted to the in vivo evaluation of the elastic properties of human skin. It uses an ultrasonic probe (50 MHz) for tracking the displacements induced by a 300 Hz shear wave generated by a ring surrounding the transducer. The displacements are measured using a conventional cross-correlation technique between successive ultrasonic back-scattered echoes. First, this noninvasive technique has been experimentally proven to be accurate for investigating elasticity in different skin-mimicking phantoms. Second, data were acquired in vivo on human forearms. As expected, Young's modulus was found to be higher in the dermis than in the hypodermis and other soft tissues. 相似文献
70.
Finnish driver training was renewed in 1990 with the inclusion of a compulsory skid training course in the curriculum. The study evaluated the renewal's effect on accidents in slippery road conditions. A questionnaire was sent by mail to 41000 novice drivers who were randomly selected from the official register of driving licences. It included questions on driving exposure and the accidents the drivers had been involved in during 6-18 months following licensing. The rate of return was 74.7%. Half of the drivers had received their licence in 1989 and had, therefore, not received any skid training. The other half had received their licence in 1990 after the introduction of the skid training course. The results showed no effects of the renewal on slippery road accidents for either male or female drivers. Another questionnaire was sent to 1300 old and new curriculum drivers immediately after licensing and a second time 1/2-1 year later, both with questions about skills, worries and perceived risks regarding driving in slippery conditions. The new curriculum drivers showed higher confidence in their skills and they were less afraid to drive in slippery conditions than the old curriculum drivers. This increase in confidence as a result of skid training is discussed. It is argued that high confidence in one's personal skills does not necessarily imply negative safety. The crucial factor is how these skills are used, and for what purpose. 相似文献