Design and evaluation of an integrated Quiet, Clean General Aviation Turbofan (QCGAT) engine and aircraft propulsion system

The design was based on the LTS-101 engine family for the core engine. A high bypass fan design (BPR=9.4) was incorporated to provide reduced fuel consumption for the design mission. All acoustic and pollutant emissions goals were achieved. A discussion of the preliminary design of a business jet suitable for the developed propulsion system is included. It is concluded that large engine technology can be successfully applied to small turbofans, and noise or pollutant levels need not be constraints for the design of future small general aviation turbofan engines

The Condominium Crisis: A Problem Unresolved

Many factors have contributed to the movement toward condominium conversion

The Condominium Crisis: A Problem Unresolved

Many factors have contributed to the movement toward condominium conversion

An island based hybrid evolutionary algorithm for optimization

This is a post-print version of the article - Copyright @ 2008 Springer-VerlagEvolutionary computation has become an important problem solving methodology among the set of search and optimization techniques. Recently, more and more different evolutionary techniques have been developed, especially hybrid evolutionary algorithms. This paper proposes an island based hybrid evolutionary algorithm (IHEA) for optimization, which is based on Particle swarm optimization (PSO), Fast Evolutionary Programming (FEP), and Estimation of Distribution Algorithm (EDA). Within IHEA, an island model is designed to cooperatively search for the global optima in search space. By combining the strengths of the three component algorithms, IHEA greatly improves the optimization performance of the three basic algorithms. Experimental results demonstrate that IHEA outperforms all the three component algorithms on the test problems.This work was supported by the Engineering and Physical Sciences Research Council (EPSRC) of UK under Grant EP/E060722/1

Lengthscales and Cooperativity in DNA Bubble Formation

It appears that thermally activated DNA bubbles of different sizes play central roles in important genetic processes. Here we show that the probability for the formation of such bubbles is regulated by the number of soft AT pairs in specific regions with lengths which at physiological temperatures are of the order of (but not equal to) the size of the bubble. The analysis is based on the Peyrard- Bishop-Dauxois model, whose equilibrium statistical properties have been accurately calculated here with a transfer integral approach

The Experience of Pregnancy for Women with Bipolar Disorder: An Exploratory Study

Background: Bipolar disorder often emerges in an individual’s late teens and early twenties, thus women with bipolar disorder are impacted for the majority of their childbearing years. Pregnancy brings a unique set of challenges to this population, including risk of relapse, teratogenicity of medications, and increased risk of postpartum psychosis, yet no research exists on this population’s experience of pregnancy. Design: This study utilized semi-structured telephone interviews to gather preliminary qualitative data on the experience of pregnancy for women with bipolar disorder with the long-term goal of developing patient education materials and improving nursing-led interventions to help manage illness during pregnancy and postpartum. Method: A purposive sample of four English-speaking women, age 29-39, with a confirmed diagnosis of bipolar disorder I or II and who had given birth within the last eighteen months, was recruited nationally via the electronic and mass media, and postings on bulletin boards in a range of educational and related settings. One open-ended focused telephone interview was held with each client, and conducted by the first author. She was also responsible for doing the audiotaping, transcription, and coding of the data using a descriptive qualitative design.  Results: Women with bipolar disorder described a unique pregnancy experience, influenced by the intersection of mental illness, pregnancy, and pharmacotherapy. Recurrent themes included hopefulness, patient and healthcare provider as advocates, the importance of interdisciplinary care, education, community support and the mixed impact of medication. Discussion & Conclusion: This research contributes to initiatives designed to improve healthcare for pregnant women with bipolar disorder, augment patient education materials, and inform the design of nurse-led interventions. Empirical research findings become even more valuable tools for improving patient care when paired with the voices of patients themselves. As pregnant women are a historically under-studied population, this study also contributes to the larger body of scientific research on this population.&nbsp

Strain-induced partially flat band, helical snake states, and interface superconductivity in topological crystalline insulators

Topological crystalline insulators in IV-VI compounds host novel topological surface states consisting of multi-valley massless Dirac fermions at low energy. Here we show that strain generically acts as an effective gauge field on these Dirac fermions and creates pseudo-Landau orbitals without breaking time-reversal symmetry. We predict the realization of this phenomenon in IV-VI semiconductor heterostructures, due to a naturally occurring misfit dislocation array at the interface that produces a periodically varying strain field. Remarkably, the zero-energy Landau orbitals form a flat band in the vicinity of the Dirac point, and coexist with a network of snake states at higher energy. We propose that the high density of states of this flat band gives rise to interface superconductivity observed in IV-VI semiconductor multilayers at unusually high temperatures, with non-BCS behavior. Our work demonstrates a new route to altering macroscopic electronic properties to achieve a partially flat band, and paves the way for realizing novel correlated states of matter.Comment: Accepted by Nature Physic

Indigenous amino acids in primitive CR meteorites

CR meteorites are among the most primitive meteorites. In this paper, we report the first measurements of amino acids in Antarctic CR meteorites, two of which show the highest amino acid concentrations ever found in a chondrite. EET92042, GRA95229 and GRO95577 were analyzed for their amino acid content using high performance liquid chromatography with UV fluorescence detection (HPLC-FD) and gas chromatographymass spectrometry (GC-MS). Our data show that EET92042 and GRA95229 are the most amino acid-rich chondrites ever analyzed, with total amino acid concentrations ranging from 180 parts-per-million (ppm) to 249 ppm. GRO95577, however, is depleted in amino acids. The most abundant amino acids present in the EET92042 and GRA95229 meteorites are the alpha-amino acids glycine, isovaline, alpha-aminoisobutyric acid (alpha-AIB), and alanine, with delta13C values ranging from +31.6per mil to +50.5per mil. The carbon isotope results together with racemic enantiomeric ratios determined for most amino acids strongly indicate an extraterrestrial origin of these compounds. In addition, the relative abundances of alpha-AIB and beta-alanine in the Antarctic CR meteorites analyzed appear to correspond to the degree of aqueous alteration on their respective parent body.Comment: In press; To appear in the December 2007 issue of Meteoritics and Planetary Science, released March 200

Cliometrics and the Nobel

JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact [email protected]. . American Economic Association is collaborating with JSTOR to digitize, preserve and extend access to The Journal of Economic Perspectives. http://www.jstor.org Given the large domain of economic history, it should not be surprisin

Introduction : Texts and Their Transformations

ハワイ州マウイ, 2000年11