Adaptive control of a class of nonlinearly perturbed linear systems of relative degree two

A simple adaptive output feedback strategy, incorporating gains of Nussbaum type, is described and is shown to be a universal stabilizer for a class of nonlinearly perturbed, single-input, linear systems of relative degree two.     

Pulsed Nano-Electrospray Ionization: Characterization of Temporal Response and Implementation with a Flared Inlet Capillary

The temporal response of pulsed nano-electrospray ionization mass spectrometry (nano-ESI-MS) was studied and its influence on ion formation and detection was characterized. Rise and decay times for the mass resolved ion current were determined to be 20 ± 3 msec and 61 ± 5 msec, respectively, which led to a maximum pulse rate of 12 Hz. Pulsed nano-ESI operation was demonstrated from a multi-sprayer source controlled by a high voltage pulsing circuit constructed in-house. The desired source mode of operation (e.g. pulsing or continuous) can be realized solely by controlling the voltage applied to each sprayer.     

The average number of block interchanges needed to sort a permutation and a recent result of Stanley

We use an interesting recent result of probabilistic flavor concerning the product of two permutations consisting of one cycle each to find an explicit formula for the average number of block interchanges needed to sort a permutation of length n.     

Measurement of Electromagnetic Shower Position and Size with a Saturated Avalanche Tube Hodoscope and a Fine Grained Scintillation Hodoscope

A hodoscope has been constructed from 100 ?m diameter wires and brass tubes (1.2 × 0.7 cm2 cross section) filled with a mixture of argon, ethane and ethyl alchohol. It has been tested in the saturated avalanche mode in an SCG1-C electromagnetic shower detector to determine its properties for the measurement of the position and size of electromagnetic showers. Two of these tube hodoscopes were positioned 3.5 radiation lengths deep in the detector and the profiles of 1-25 GeV electromagnetic showers were measured. Simultaneous measurements were performed using a plane of twenty, 0.5 cm wide scintillation counters positioned immediately behind the gas tube hodoscope. In addition the transition between saturated avalanche and limited streamer modes has been measured for the tube hodoscopes.     

The expression of stem cell factor and its receptor, c-kit in human endometrium and placental tissues during pregnancy

Stem cell factor (SCF) and its receptor Kit regulate the proliferation and survival of early hematopoietic cell types as well as germ cells and melanocytes. As SCF augments the effects of several hematopoietic growth factors that are produced in reproductive tissues during pregnancy and also plays an important role in cell migration, proliferation, and survival, we studied the expression and localization of this receptor/ligand in human endometrial and placental tissues. Kit was detected by Western blot analysis in early decidual and placental tissues (8-19 weeks gestation) and in term placenta. Immunohistochemistry localized Kit mainly in trophoblast and to a lesser extent in scattered cells in the placental villous core and decidual stroma. Ribonuclease protection assay showed that SCF messenger ribonucleic acid (mRNA) expression increased 3-fold in decidua from early pregnancy compared to proliferative and secretory endometrium (P < 0.05). Placental tissues expressed 4- to 8-fold higher levels of SCF mRNA compared to decidus (P < 0.05). Isolated placental villous core expressed 7-fold higher levels of SCF mRNA than did trophoblast (P < 0.05). Thus, SCF and its receptor Kit are expressed in human endometrium and placental tissues during pregnancy, and the pattern of receptor/ligand expression suggests that endometrial and placental villous core SCF may have a paracrine effect on trophoblast through the receptor Kit.     

Metallurgical stability of ohmic contacts on thin baseInP/InGaAs/InP HBT's

The metallurgical stability of ohmic contacts: Pt, Pt/Ti, Au/Ti, Au/Pt/Ti, and Au/Pt/Ti/W, on a 500 Å thick p⁺-InGaAs base of InP/InGaAs/InP HBTs have been investigated as a function of anneal temperature. All contacts were stable after a 300°C-30 s anneal. Pt contact failed at 350°C whereas Pt/Ti, Au/Ti, and Au/Pt/Ti contacts failed at 400°C. The failure mechanism was a collector leakage short owing to the penetration of Pt or Ti through the thin base. Only HBTs with Au/Pt/Ti/W contact were still functional after a 400°C anneal with no apparent shift in the turn-on voltage for the emitter and collector junctions     

Effects of oil properties on spark-ignition gasoline engine friction

The effects of base oil, friction modifier (FM) and viscosity grade on firing engine friction are investigated in an automotive gasoline engine. Unique aspects of the study are (1) viscosity grade is maintained when synthetic and conventional base oils are compared, (2) the influence of engine operating condition on the effectiveness of base oil, FM and viscosity grade in reducing engine friction is considered, and (3) friction-relevant design details of the test engine are discussed. Results show that replacing conventional oil with synthetic oil of the same viscosity grade reduces friction, especially at high boundary friction conditions. Molybdenum dithiocarbamate (MoDTC), and to a lesser extent organic FM, also reduce friction, especially at high boundary friction conditions. Furthermore, using 5W-20 oil causes less friction than 5W-30 and 10W-40 oil at both high and low boundary friction conditions. Results are expected to hold true for engines with similar friction-relevant designs.     

SYSTEMS DEVELOPMENT THE TEAM METAPHOR

Strong businesses are built on teams of people working together to get the job done. The team metaphor is the model on which to base future computing solutions. Applications for communication and routing, information exchange, process management, collaboration, and meetings are discussed.     

Pharmacokinetics of minoxidil in patients with cirrhosis and healthy volunteers

OBJECTIVES: To determine the effect of reduced hepatic function on the pharmacokinetics of minoxidil. The pharmacokinetics of antipyrine, lorazepam, and indocyanine green were included as indicators of hepatic function. METHODS: Eight mild cirrhotics and eight healthy subjects received antipyrine (po), lorazepam (IV), indocyanine green (IV) and minoxidil 5 mg (po). Blood and urine were sampled for up to 72 h after each drug, and drug concentrations were measured by validated HPLC methods. Blood pressure and heart rate were measured for safety. RESULTS: For unchanged minoxidil, the serum elimination rate constant was significantly smaller and mean residence time was significantly longer in cirrhotic patients. Urinary elimination rate constant for minoxidil glucuronide was significantly smaller and fraction of dose excreted in urine was significantly higher in cirrhotic patients. Antipyrine elimination was significantly slower for cirrhotic patients. No differences were observed in lorazepam pharmacokinetic parameters. CONCLUSION: Pharmacokinetic analysis suggests a longer dosage interval may be appropriate in patients with hepatic impairment. In the absence of multiple-dose minoxidil pharmacodynamic studies in this population, minoxidil should be used as in other populations: begin with a modest dose, and adjust the dose based on clinical response.