Digital video for networked CAL delivery

Digital moving images (AVI format), were integrated into a specific computer-assisted learning (CAL) application, providing a highly visual and interactive self-learning tool in an area of the medical curriculum which is difficult to teach by traditional methods. This paper outlines the process used to obtain the digital video using relatively inexpensive equipment and the subsequent delivery over a university network without resorting to major upgrading of the network specifications.     

Upper stage flight experiment (USFE) integral structure development effort

The Air Force Research Laboratory's Space Vehicle Directorate (AFRL/VS) has established a customer focused composite tankage development program that is targeted to existing and future aerospace applications. AFRL/VS is developing a wide range of tank concepts that include linerless cryogenic tankage, self-healing cryogenic tankage, hydrogen peroxide compatible tankage, volumetrically efficient toroidal (donut shaped) geometries, and more.

This paper will summarize the Upper Stage Flight Experiment (USFE) composite integral structure development effort. The integral structure refers to the stage skirt and the propellant tankage. These two parts are bonded together to form an integral structure. The USFE tank is the world's first composite, common-bulkhead, medium-pressure vessel designed to be Class 1 Compatible with high concentrations of hydrogen peroxide. Lightweight hydrogen peroxide compatible tankage development is becoming increasingly important to the international aerospace community because it provides considerable benefits. Peroxide can be stored unpressurized and is relatively non-toxic, which makes it safer to handle and store compared to oxidizers such as hydrazine. In addition to being a viable bi-propellant oxidizer, hydrogen peroxide can also serve as a monopropellant for an attitude control system (ACS). Peroxide is not cryogenic, therefore, it does not require an on-board cryocooler, which makes it easier to meet mass budgets and to mitigate technical risk. Storability and ease of handling make high concentration hydrogen peroxide an ideal propellant for reusable launch vehicle (RLV) responsive upper stage applications.     

Neutralization of acidic lakes: Short-term dissolution of dry and slurried calcite

Two clear, acidic lakes in Ontario were neutralized with calcite applied with a large, fixed-wing aircraft (Canso). The initial calcite dissolution efficiencies were predicted with the Sverdrup model. Bowland Lake (pH 5.0) was neutralized with a calcite powder (mean particle dia 9.1 μm) applied in dry form and the observed to predicted initial dissolution ratio (R_T) was 0.77. Trout Lake (pH 5.9) was neutralized with a calcite powder (mean particle diameter 5.4 μm) applied in a 70% slurry with R_T = 0.90. Hence, dissolution was enhanced when calcite was applied as a slurry. Dosage estimates derived from the Sverdrup model should be adjusted to account for lowered dissolution when applying calcite in dry form and when applying calcite with a large fixed-wing aircraft.Dissolution of settled calcite was observed in Bowland Lake following application. Dissolution of settled calcite was undetectable in Trout Lake, probably because of the smaller amount of settled calcite.     

Quantitative Investigation of QRS Detection Rules Using the MIT/BIH Arrhythmia Database

We have investigated the quantitative effects of a number of common elements of QRS detection rules using the MIT/BIH arrhythmia database. A previously developed linear and nonlinear filtering scheme was used to provide input to the QRS detector decision section. We used the filtering to preprocess the database. This yielded a set of event vectors produced from QRS complexes and noise. After this preprocessing, we tested different decision rules on the event vectors. This step was carried out at processing speeds up to 100 times faster than real time. The role of the decision rule section is to discriminate the QRS events from the noise events. We started by optimizing a simple decision rule. Then we developed a progressively more complex decision process for QRS detection by adding new detection rules. We implemented and tested a final real-time QRS detection algorithm, using the optimized decision rule process. The resulting QRS detection algorithm has a sensitivity of 99.69 percent and positive predictivity of 99.77 percent when evaluated with the MIT/BIH arrhythmia database.     

L- and T-type calcium currents differ in finch and rat ventricular cardiomyocytes

We compared L-type Ca current (ICaL) and T-type Ca current (ICaT) in finch and rat myocytes, using whole-cell patch clamp techniques. Cell capacitance averaged 50 +/- 4 pF in finch (n = 25) v 145 +/- 8 pF in rat (n = 38) cells, P < 0.001. In cells bathed in 1 mM Cao at 22 degrees C, peak ICaL amplitude, during a voltage clamp step (10 mM EGTA in pipette) from -45 mV to -5 mV, averaged 10.5 +/- 0.3 pA/pF in finch v 6.9 +/- 0.6 pA/pF, P < 0.001 in rat cells. ICaL inactivation kinetics were faster in finch (4.6 +/- 0.3 ms) than in rat (13.4 +/- 1.3 ms) cells. P < 0.001. ICaT was not detectable in rat cells (2 mM bathing [Ca]); but in finch cells, a large ICaT which averaged 6.8 +/- 1.4 pA/pF was activated at -30 mV and was relatively insensitive to nitrendipine (0.1 microM). The distinctive features of ICaL and ICaT in finch cells may have a role in the ability of the finch to achieve a very rapid heart rate. They may also facilitate excitation-Ca2+ release coupling in finch ventricular cells which are devoid of T tubules and have relatively few junctions between the sarcolemma and the sarcoplasmic reticulum.