4,501 research outputs found
Toward Clemens' Conjecture in degrees between 10 and 24
We introduce and study a likely condition that implies the following form of
Clemens' conjecture in degrees between 10 and 24: given a general quintic
threefold in complex \IP^4, the Hilbert scheme of rational, smooth and
irreducible curves of degree on is finite, nonempty, and reduced;
moreover, each is embedded in with balanced normal sheaf
\O(-1)\oplus\O(-1), and in \IP^4 with maximal rank.Comment: Plain Tex, This eleven page paper is a joint manuscript, produced in
connection with the first author's participation in the conference "Geometry
and Physics", Zlatograd, Bulgaria, August 28 - Sept.2, 1995." This version
contains a small change in Remark (3.3); the hope expressed there has been
refine
Preliminary analysis of a downsized advanced gas-turbine engine in a subcompact car
Relative fuel economy advantages exist for a ceramic turbine engine when it is downsized for a small car were investigated. A 75 kW (100 hp) single shaft engine under development was analytically downsized to 37 kW (50 hp) and analyzed with a metal belt continuously variable transmission in a synthesized car. With gasoline, a 25% advantage was calculated over that of a current spark ignition engine, scaled to the same power, using the same transmission and car. With diesel fuel, a 21% advantage was calculated over that of a similar diesel engine vehicle
Operating condition and geometry effects on low-frequency afterburner combustion instability in a turbofan at altitude
Three afterburner configurations were tested in a low-bypass-ratio turbofan engine to determine the effect of various fuel distributions, inlet conditions, flameholder geometry, and fuel injection location on combustion instability. Tests were conducted at simulated flight conditions of Mach 0.75 and 1.3 at altitudes from 11,580 to 14,020 m (38,000 to 46,000 ft). In these tests combustion instability with frequency from 28 to 90 Hz and peak-to-peak pressure amplitude up to 46.5 percent of the afterburner inlet total pressure level was encountered. Combustion instability was suppressed in these tests by varying the fuel distribution in the afterburner
Altitude test of several afterburner configurations on a turbofan engine with a hydrogen heater to simulate an elevated turbine discharge temperature
A performance test of several experimental afterburner configurations was conducted with a mixed-flow turbofan engine in an altitude facility. The simulated flight conditions were for Mach 1.4 at two altitudes, 12,190 and 14,630 meters. Turbine discharge temperatures of 889 and 1056 K were used. A production afterburner was tested for comparison. The research afterburners included partial forced mixers with V-gutter flameholders, a carburetted V-gutter flameholder, and a triple ring V-gutter flameholder with four swirl-can fuel mixers. Fuel injection variations were included. Performance data shown include augmented thrust ratio, thrust specific fuel consumption, combustion efficiency, and total pressure drop across the afterburner
Reactions of Na/plus/, K/plus/, and Ba/plus/ ions with O2, NO, and H2O molecules
Investigating ion molecule reactions of sodium, potassium, and barium ions with oxygen, nitric oxide, and water in drift tube mass spectromete
A class of well-posed parabolic final value problems
This paper focuses on parabolic final value problems, and well-posedness is
proved for a large class of these. The clarification is obtained from Hilbert
spaces that characterise data that give existence, uniqueness and stability of
the solutions. The data space is the graph normed domain of an unbounded
operator that maps final states to the corresponding initial states. It induces
a new compatibility condition, depending crucially on the fact that analytic
semigroups always are invertible in the class of closed operators. Lax--Milgram
operators in vector distribution spaces constitute the main framework. The
final value heat conduction problem on a smooth open set is also proved to be
well posed, and non-zero Dirichlet data are shown to require an extended
compatibility condition obtained by adding an improper Bochner integral.Comment: 16 pages. To appear in "Applied and numerical harmonic analysis"; a
reference update. Conference contribution, based on arXiv:1707.02136, with
some further development
A type system for components
In modern distributed systems, dynamic reconfiguration, i.e.,
changing at runtime the communication pattern of a program, is chal-
lenging. Generally, it is difficult to guarantee that such modifications will
not disrupt ongoing computations. In a previous paper, a solution to this
problem was proposed by extending the object-oriented language ABS
with a component model allowing the programmer to: i) perform up-
dates on objects by means of communication ports and their rebinding;
and ii) precisely specify when such updates can safely occur in an object
by means of critical sections. However, improper rebind operations could
still occur and lead to runtime errors. The present paper introduces a
type system for this component model that extends the ABS type system
with the notion of ports and a precise analysis that statically enforces
that no object will attempt illegal rebinding
A Student\u27s Perspective of Learning on a Dedicated Education Unit
It is the intent of this honors project to give a student’s perspective of learning in the Dedicated Education Unit (DEU) on Bridge 7 at Rhode Island Hospital. Bridge 7 is a 38-bed unit specializing in general medical surgical patient care services. A student’s perspective is illustrated by journal entries written from each clinical experience over the course of one semester, during the course Adult Health II. In addition to a student’s perspective, it is the intention to compare the learning experience on the DEU, to the traditional model of clinical learning. This project will include current nursing research that focuses on different areas of dedicated education unit learning. Findings from these nursing research articles will be compared and contrasted to a student’s perspective of the same outcomes. Prior to each clinical day, students set personal goals. These personal goals will be addressed, with a focus on how learning on a DEU enhanced goal attainment. Lastly, well-known nursing theorist Pat Benner’s conceptual model of how nurses evolve from novice to expert will be utilized and directly incorporated into the student’s perspective
- …