Performance, emissions, and physical characteristics of a rotating combustion aircraft engine, supplement A

Testing was conducted using the basic RC2-75 engine, to which several modifications were incorporated which were designed to reduce the hydrocarbon emissions and reduce the specific fuel consumption. The modifications included close-in surface gap spark plugs, increased compression ratio rotors, and provisions for utilizing either side or peripheral intake ports, or a combination of the two if required. The proposed EPA emissions requirements were met using the normal peripheral porting. The specific fuel economy demonstrated for the modified RC2-75 was 283 g/kW-hr at 75% power and 101 brake mean effective pressure (BMEP) and 272.5 g/kW-hr at 75% power and 111 BMEP. The latter would result from rating the engine for takeoff at 285 hp and 5500 rpm, instead of 6000 rpm

Phenomena of Cathode Sputtering

When metal is deposited cathodically upon a glass plate a film is found upon the side of the plate away from the cathode. In the study of this deposit both alternating and direct potentials were employed. An attempt to increase the deposit by various reflecting surfaces gave negative results. A possible explanation of the phenomenon is offered, based upon the assumption that the metallic particles receive a positive charge after leaving the cathode. An attempt to sputter non-conductors in the form of metallic oxides gave negative results

The effects of smoking cessation on control of food intake in postmenopausal African-American and Caucasian women

Smoking cessation leads to greater weight gain in women than men, and older and postmenopausal women are at greater risk for weight gain than younger, premenopausal women. African-American postmenopausal women may be at the greatest risk. Weight gain after smoking cessation is primarily due to increased caloric intake. Currently, the literature regarding measurement of macronutrient intake after smoking cessation is plagued with methodological problems. The Geiselman Macronutrient Self-Selection Paradigm (MSSP) significantly and systematically varies fat across other macronutrients and the Geiselman Food Preference Questionnaire (FPQ) measures the negative feedback of satiation via pre- and postprandial hedonic ratings of foods. Fifty-five Caucasian and 32 African-American postmenopausal women were recruited for the present study. We measured changes in total caloric intake, and specific macronutrient intake with the use of the MSSP, and we measured hedonic ratings with the use of the FPQ before and after smoking cessation. We hypothesized that total caloric intake and intake of high-fat foods would increase postcessation. Also, we hypothesized that women would be able to reach satiation more readily while smoking than they would postcessation. We found that Caucasian females increased total caloric intake and intake of high-fat foods after smoking cessation; however, their level of satiation did not change from pre- to postcessation. Thus, the Caucasian women had to ingest significantly more total kcals, especially from high-fat foods, postcessation to achieve the same level of satiation that they reached with much smaller amount of food while still smoking. Total caloric intake, including intake of high-fat foods, did not differ from pre- to postcessation in African-American females. African-American women ingested significantly more total kcals and intake of high-fat foods than did Caucasian females, regardless of smoking status. African-American women also showed significantly smaller decreases in hedonic ratings of high-fat foods from pre- to postprandial than did Caucasian women, indicating less satiating effect of high-fat foods in the African-American females

Topological entropy and blocking cost for geodesics in riemannian manifolds

For a pair of points $x,y$ in a compact, riemannian manifold $M$ let $n_t(x,y)$ (resp. $s_t(x,y)$) be the number of geodesic segments with length $\leq t$ joining these points (resp. the minimal number of point obstacles needed to block them). We study relationships between the growth rates of $n_t(x,y)$ and $s_t(x,y)$ as $t\to\infty$. We derive lower bounds on $s_t(x,y)$ in terms of the topological entropy $h(M)$ and its fundamental group. This strengthens the results of Burns-Gutkin \cite{BG06} and Lafont-Schmidt \cite{LS}. For instance, by \cite{BG06,LS}, $h(M)>0$ implies that $s$ is unbounded; we show that $s$ grows exponentially, with the rate at least $h(M)/2$.Comment: 13 page

Exploratory Analysis of Highly Heterogeneous Document Collections

We present an effective multifaceted system for exploratory analysis of highly heterogeneous document collections. Our system is based on intelligently tagging individual documents in a purely automated fashion and exploiting these tags in a powerful faceted browsing framework. Tagging strategies employed include both unsupervised and supervised approaches based on machine learning and natural language processing. As one of our key tagging strategies, we introduce the KERA algorithm (Keyword Extraction for Reports and Articles). KERA extracts topic-representative terms from individual documents in a purely unsupervised fashion and is revealed to be significantly more effective than state-of-the-art methods. Finally, we evaluate our system in its ability to help users locate documents pertaining to military critical technologies buried deep in a large heterogeneous sea of information.Comment: 9 pages; KDD 2013: 19th ACM SIGKDD Conference on Knowledge Discovery and Data Minin

Transonic pressure measurements and comparison of theory to experiment for an arrow-wing configuration. Volume 1: Experimental data report, base configuration and effects of wing twist and leading-edge configuration

A wind tunnel test of an arrow-wing-body configuration consisting of flat and twisted wings, as well as a variety of leading- and trailing-edge control surface deflections, was conducted at Mach numbers from 0.4 to 1.1 to provide an experimental pressure data base for comparison with theoretical methods. Theory-to-experiment comparisons of detailed pressure distributions were made using current state-of-the-art attached and separated flow methods. The purpose of these comparisons was to delineate conditions under which these theories are valid for both flat and twisted wings and to explore the use of empirical methods to correct the theoretical methods where theory is deficient