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11.
A micromachined hot-film anemometer on a high-pressure stable substrate is demonstrated to be suitable for "on-board" measurements of various injection quantities, which are needed in modern direct injection systems for optimum performance of diesel, as well as gasoline, engines. To estimate the velocity profile in the injection nozzle during the injection pulse, two-dimensional finite element method calculations are performed. To consider the substrate effect on the performance of the thermal injection rate sensor, an IR imaging system is used to determine the heat loss via the robust glass ceramic substrate up to thin-film temperatures of 450 K in air. Using both the numerical and the experimental results, the temperature sensitivity and velocity sensitivity of hot-film anemometers, operated in the constant current mode in a fuel atmosphere, can be modeled analytically. Finally, an overview about the results of the latest injection rate measurements at fuel pressures up to 60 MPa and drive pulse lengths between 0.2-5 ms is given. Comparing these signals of the thermal thin-film sensor to injection volume measurements, performed with an injection amount indicator at a high-pressure hydraulic test bench, the mass flow measurements can be calibrated. One empiric parameter is necessary, which is the exponent of a power law dependence on the maximum sensor amplitude during injection. 相似文献
12.
E Schmid 《Canadian Metallurgical Quarterly》1993,108(4):313-321
The intention of the following report is to present a concept for constructing a substitute glottis (neoglottis). The concept evolved over the years on the basis of anatomic studies and in the course of plastic reconstructions on patients. It is based on pedicled grafting of a voluntarily controllable--and hence trainable--musculature that might be transplanted into the larynx attached to a neurovascular pedicle. A rima glottidis might be imitated that could be opened and closed from a neutral position. During sleep the neoglottis would be in a relaxed, spasm-free position. A sensitive and tactile stimulus response ought to be possible, as should variations of the state of tension of the substitute vocal muscles. 相似文献
13.
14.
MB Schmid 《Canadian Metallurgical Quarterly》1998,2(4):529-534
OBJECTIVE: To examine the cost-effectiveness of prenatal carrier screening for cystic fibrosis. METHODS: A cost-benefit equation was developed that was based on the hypothesis that the cost of prenatal diagnosis required to diagnose and prevent one case of cystic fibrosis should be equal to or less than the lifetime cost generated from the birth of a neonate with cystic fibrosis. The formula was adjusted because a woman's positive or negative carrier status remains unchanged, thus eliminating the need for testing in subsequent pregnancies. The formula was manipulated to identify the optimal cost per screening test, as well as the net cost savings per prenatally diagnosed case of cystic fibrosis for various racial or ethnic groups. Sensitivity analyses included some key assumptions regarding the cost per screening test ($50-150), patient screening acceptance rates (25-100%), and therapeutic abortion rates (50-100%). RESULTS: Assuming therapeutic abortion rates of 50-100%, the net savings per prenatally diagnosed case of cystic fibrosis are $58,369-$382,369 among whites. Given the previously reported patient screening acceptance rates of 50-78%, the overall annual cost savings in the United States for whites are $161-251 million. However, the screening program was not found to be cost-effective for blacks, Asians, or Hispanics. CONCLUSION: Under most assumptions and sensitivity analyses, a prenatal cystic fibrosis-carrier screening program appears to be cost-effective. 相似文献
15.
W. Schmid C. Jung B. Weigi G. Reiner R. Michalzik K.J. Ebeling 《Photonics Technology Letters, IEEE》1996,8(10):1288-1290
We report on high-resolution linewidth measurements of proton-implanted InGaAs-GaAs VCSELs employing the delayed self-heterodyne method. Devices with 16-/spl mu/m active diameter exhibit record low linewidths of 20 MHz and 4-MHz residual linewidth. The linewidth enhancement factor is accurately determined from the ratio of induced phase to amplitude modulation indexes. 相似文献
16.
Wolfgang Schmid und Werner Grosch 《Zeitschrift für Lebensmitteluntersuchung und -Forschung A》1986,183(1):39-44
Zusammenfassung Sieben Aromastoffe, isoliert durch Destillation im Vakuum aus Sauer- und Süßkirschprodukten, wurden vergleichend analysiert. In den frisch gepreßten Säften aus je fünf Sorten Sauer- und Süßkirschen wurden große Konzentrationsunterschiede (gm/l) gefunden: Benzaldehyd (18–393), Linalool (0,5–1,7), Hexanal (0,3–54,7), 2(E)-Hexenal (2,4220), 2(E),6(Z)-Nonadienal (0,1–2,4), Phenylacetaldehyd (2,1–5,6) und Eugenol (1,0–22,2). Die Benzaldehydkonzentration zeigte die höchste Korrelation zur Erkennungsschwelle für den Kirschgeruch der Säfte. Bei der Herstellung von Konfitüren veränderte sich die Zusammensetzung der Aromastoffe: Benzaldehyd und Linalool nahmen um den Faktor 7 bzw. 13 zu; Hexanal, 2(E)-Hexenal sowie Phenylacetaldehyd nahmen stark ab. Der Anstieg von Benzaldehyd und Linalool, der auch bei der simultanen Destillation/Extraktion der Säfte auftrat, beruht auf einer Hydrolyse entsprechender Glykoside, die durch eine Hitzebehandlung stark beschleunigt wird.
Quantitative analysis of the volatile flavour compounds having high aroma values from sour (Prunus cerasus L.) and sweet (Prunus apium L.) cherry juices and jams
Summary The analysis results for seven of the aroma compounds obtained by vacuum distillation from sweet and sour cherry products were compared. The freshly pressed juices from 5 varieties of sour and 5 varieties of sweet cherries showed great differences in concentrations (g/1): benzaldehyde (18–393), linalool (0.5–1.7), hexanal (0.3–54.7), 2(E)-hexenal (2.4–220), 2(E),6(Z)-nonadienal (0.1–2.4), phenylacetaldehyde (2.1–5.6) and eugenol (1.0–22.2). The benzaldehyde content of the juices showed the highest correlation to the recognition threshold of the cherry aroma note. The cherry jam showed a drastic change in the aroma composition: benzaldehyde and linalool increased greatly (7 and 13-times, respectively), while hexanal, 2(E)-hexenal and phenylacetaldehyde strongly decreased. The increase in benzaldehyde and linalool, which was also observed during simultaneous distillation/extraction of the juices, is caused by the hydrolysis of the corresponding glycosides during the heat treatments.相似文献
17.
Florian A. Schmid J. Koudy Williams Thomas M. Kessler Arnulf Stenzl Wilhelm K. Aicher Karl-Erik Andersson Daniel Eberli 《International journal of molecular sciences》2021,22(8)
Urinary incontinence (UI) is a major problem in health care and more than 400 million people worldwide suffer from involuntary loss of urine. With an increase in the aging population, UI is likely to become even more prominent over the next decades and the economic burden is substantial. Among the different subtypes of UI, stress urinary incontinence (SUI) is the most prevalent and focus of this review. The main underlying causes for SUI are pregnancy and childbirth, accidents with direct trauma to the pelvis or medical treatments that affect the pelvic floor, such as surgery or irradiation. Conservative approaches for the treatment of SUI are pelvic physiotherapy, behavioral and lifestyle changes, and the use of pessaries. Current surgical treatment options include slings, colposuspensions, bulking agents and artificial urinary sphincters. These treatments have limitations with effectiveness and bear the risk of long-term side effects. Furthermore, surgical options do not treat the underlying pathophysiological causes of SUI. Thus, there is an urgent need for alternative treatments, which are effective, minimally invasive and have only a limited risk for adverse effects. Regenerative medicine is an emerging field, focusing on the repair, replacement or regeneration of human tissues and organs using precursor cells and their components. This article critically reviews recent advances in the therapeutic strategies for the management of SUI and outlines future possibilities and challenges. 相似文献
18.
Xiaohong Gu Tinh Nguyen Mounira Oudina David Martin Bouchra Kidah Joan Jasmin Aziz Rezig Lipiin Sung Eric Byrd Jonathan W. Martin Derek L. Ho Y. C. Jean 《Journal of Coatings Technology and Research》2005,2(7):547-556
Atomic force microscopy (AFM) has been used to study the morphology and microstructure of an amine-cured epoxy before and
after outdoor exposure. Measurements were made from samples prepared in an essentially CO2-free, H2O-free glove box and from samples prepared in ambient conditions. For those prepared in a CO2-free glove box, AFM imaging was conducted on (1) an unexposed air/coating surface, (2) an unexposed coating bulk, (3) an
unexposed coating/substrate interface, and (4) a field exposed air/coating surface. For samples prepared in ambient conditions,
only the unexposed air/coating surface was investigated. The same regions of the exposed samples were scanned periodically
by the AFM to monitor changes in the surface morphology of the coating as UV exposure progressed. Small angle neutron scattering
and Fourier transform infrared spectroscopy (FTIR) studies were performed to verify the microstructure and to follow chemical
changes during outdoor exposure, respectively. The results have shown that amine blushing, which occurs only under ambient
conditions, had a significant effect on the surface morphology and microstructure of the epoxy. The surface morphology of
the samples prepared under CO2-free, dry conditions was generally smooth and homogeneous. However, the interface and the bulk samples clearly revealed a
two-phase structure consisting of bright nodular domains and dark interstitial regions, indicating an inhomogeneous microstructure.
Such heterogeneous structure of the bulk was in good agreement with results obtained by small angle neutron scattering of
unexposed samples and by AFM phase imaging of the degraded sample surface. The relationship between submicrometer physical
changes and molecular chemical degradation is discussed.
Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004, in Chicago,
IL. 相似文献
19.
We consider the classic problem of pole placement by state feedback. We offer an eigenstructure assignment algorithm to obtain a novel parametric form for the pole-placing feedback matrix that can deliver any set of desired closed-loop eigenvalues, with any desired multiplicities. This parametric formula is then exploited to introduce an unconstrained nonlinear optimisation algorithm to obtain a feedback matrix that delivers the desired pole placement with optimal robustness and minimum gain. Lastly we compare the performance of our method against several others from the recent literature. 相似文献
20.
Li-Piin Sung Joan Jasmin Xiaohong Gu Tinh Nguyen Jonathan W. Martin 《Journal of Coatings Technology and Research》2004,1(4):267-276
Laser scanning confocal microscopy (LSCM) has been used to characterize the changes in film thickness and local surface morphology
of polymer coatings during the UV degradation process. With the noninvasive feature of LSCM, one can obtain thickness information
directly and nondestructively at various exposure times without destroying the specimens or deriving the thickness values
from IR measurement by assuming uniform film ablation. Two acrylic polymer coatings were chosen for the study, and the physical
and chemical changes of the two systems at various exposure times were measured and analyzed. Those measurable physical changes
caused by UV exposure include film ablation, formation of pits and other surface defects, and increases in surface roughness.
It was found in both coatings that changes in measured film thickness by LSCM were not correlated linearly to the predicted
thickness loss using the changes in the CH band obtained by the Fourier Transform Infrared (FTIR) spectroscopy measurements
in the later degradation stages. This result suggested it was not a uniform film ablation process during the UV degradation.
At later stages, where surface deformation became severe, surface roughness and profile information using LSCM were also proven
to be useful for analyzing the surface degradation process
Presented at the 81st Annual Meeting of the Federation of Societies for Coatings Technology, November 13–14, 2004 in Philadelphia,
PA. 相似文献