Theoretical and experimental investigations of a novel hot-film anemometer for high-pressure automotive applications

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.     

Possible methods of creating a functional neoglottis and of constructing a functionally adequate neolarynx

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.     

Novel approaches to the discovery of antimicrobial agents

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.     

From LTL to unambiguous Büchi automata via disambiguation of alternating automata

Formal Methods in System Design - Due to the high complexity of translating linear temporal logic (LTL) to deterministic automata, several forms of “restricted” nondeterminism have been...