Emission Characteristics of an Axially Staged Sector Combustor for a Small Core High OPR Subsonic Aircraft Engine

This paper presents the nitrogen oxides, carbon monoxide, and particulate matter emissions of a single sector axially staged combustor sector designed and fabricated by United Technologies Research Center (UTRC) in partnership with NASA under a compact low-emissions combustor contract supported by the NASA Advanced Air Transport Technology (AATT) N+3 project. The test was conducted at NASA Glenn Research Center's CE-5 combustion test facility. The facility provided inlet air temperatures up to 922 K and pressures up to 19.0 bar. The combustor design concept, called Axially Controlled Stoichiometry (ACS), was developed by Pratt & Whitney (P&W) under NASA's Environmentally Responsible Aviation (ERA) program for an N+2 combustor for use in twin-aisle subsonic aircraft engines. Under the N+3 project the ACS combustor was scaled-down for application to small-core N+3 engines for use in single-aisle aircraft. The results show that the NOx and CO emissions characteristics are similar in both the N+2 and N+3 applications. The non-volatile particulate matter (nvPM) emissions trends are similar to CO emissions with an exception at high fuel-air ratio, as inlet air temperature and pressure conditions change from taxi to approach. Three NOx correlation equations are generated to describe theNOx emissions of this combustor. The percentage landing and takeoff (LTO) NOx reduction of the N+3 ACS combustor is between 82% and 89% relative to the ICAO CAEP/6 standard, which meets the NASA N+3 goal of exceeding 80% LTO NOx reduction

Grands et petits planteurs de caoutchouc en Afrique (1934-1973)

En 1933, l’Afrique ne compte plus que pour 0,2 % de la production mondiale de caoutchouc naturel. Cependant, un cartel fait remonter les prix à partir de 1934, sans appliquer de contraintes aux producteurs africains, et les grandes sociétés transfèrent des techniques d’Asie en Afrique. De 1942 à 1945, les Japonais ayant saisi la plupart des hévéas en Asie, on intensifie la saignée, on récupère des arbres abandonnés, et on relance la collecte du caoutchouc sauvage (Landolphia, Funtumia, etc.). En 1945, l’Afrique en arrive à récolter 28 % du caoutchouc naturel mondial. On plante aussi beaucoup d’hévéas, qui ne rendent qu’après 5 à 7 ans mais qui vivent de 35 à 40 ans. Après 1945, l’Asie entre en crise politique, donnant un avantage à l’Afrique, surtout aux petits planteurs du Nigéria. En 1972-1974, l’Afrique produit encore 6,8 % du caoutchouc naturel dans le monde. Mais l’industrie du caoutchouc synthétique se développe en occident, l’Asie sort de ses crises, et les indépendances africaines génèrent des politiques économiques désastreuses. La flambée des prix du pétrole en 1973 freine la montée du caoutchouc synthétique, et relance le caoutchouc naturel en Asie, mais l’Afrique est incapable de profiter de cette conjoncture avantageuse.In 1933, Africa accounted for only 0.2% of the world’s natural rubber output. However, an international cartel pushed up prices from 1934, without constraining African producers, and large firms transferred technologies from Asia. From 1942 to 1945, the Japanese having seized most Asian heveas, tapping was intensified, abandoned trees were rescued, and the collection of wild rubber started again (Landolphia, Funtumia, etc.). In 1945, Africa achieved 28% of global production of natural rubber.;Many heveas were also planted, only yielding after 5 to 7 years, but living for 35 to 40 years. After 1945, Asia entered into a period of political crisis, giving an advantage to Africa, especially to Nigerian smallholders. In 1972-74, Africa still produced 6.8% of the world’s natural rubber. However, the synthetic rubber industry grew in the West, Asia overcame its crises, and independence led African states to adopt disastrous economic policies. The surge in oil prices in 1973 hampered synthetic rubber, and stimulated natural rubber in Asia, but Africa was unable to take advantage of this favourable situation

Proceedings, International Taxus Symposium, October 1, 1975

History and development of Taxus in the U.S. / Ray A. Keen -- The best of the Taxus cultivars / L. C. Chadwick -- Poisonous properties of Taxus / Jack L. Beal -- Production of Taxus / Arie J. Radder -- Effective use of Taxus in the landscape / Clarence E. Lewis -- Taxus species and hybrids / Harold G. Hillier -- Japanese yew (Taxus cuspidata) / Makoto Kawase -- Fertilizing Taxus for optimum growth / Elton M. Smith -- Taxus insects: problems and research in Ohio / David G. Nielsen -- Taxus locations in the Secrest Arboretu

Earthquake research in China

A visit to China of an American seismological delegation, which took place October 5 to November 5, 1974, is covered in this report. The Americans were sponsored by the Committee on Scholarly Communication with the People's Republic of China (CSCPRC), and the hosts in China were the Scientific and Technical Association and the State Seismological Bureau. The CSCPRC is sponsored jointly by the National Academy of Sciences, the Social Science Research Council, and the American Council of Learned Societies. The visit had its origins in an invitation extended in January 1973 by Carl Kisslinger, as President of the Seismological Society of America, to the Chinese Academy of Sciences to send representatives to a Symposium on Earthquake Prediction Research. Although the Chinese declined to participate, this invitation was one step towards a reciprocal exchange of seismologists between the United States and the People's Republic of China. Several months after Kisslinger's letter the CSCPRC visited Peking. Their purpose was to arrange an exchange program with the Chinese Scientific and Technical Association. Prompted by Kisslinger, the committee's proposals for American delegations included seismology. Not only was this particular exchange accepted, but the Chinese in turn suggested that a Chinese seismology group visit the United States

1938: Abilene Christian College Bible Lectures - Full Text

Delivered in the Auditorium of Abilene Christian College, February, 1938 Abilene, Texas. Published October, 1939 PRICE, $1.00 FIRM FOUNDATION PUBLISHING HOUSE Austin, Texas

Theoretical Risk of Genetic Reassortment Should Not Impede Development of Live, Attenuated Rift Valley Fever (RVF) Vaccines Commentary on the Draft WHO RVF Target Product Profile

In November 2019, The World Health Organization (WHO) issued a draft set of Target Product Profiles (TPPs) describing optimal and minimally acceptable targets for vaccines against Rift Valley fever (RVF), a Phlebovirus with a three segmented genome, in both humans and ruminants. The TPPs contained rigid requirements to protect against genomic reassortment of live, attenuated vaccines (LAVs) with wild-type RVF virus (RVFV), which place undue constraints on development and regulatory approval of LAVs. We review the current LAVs in use and in development, and conclude that there is no evidence that reassortment between LAVs and wild-type RVFV has occurred during field use, that such a reassortment event if it occurred would have no untoward consequence, and that the TPPs should be revised to provide a more balanced assessment of the benefits versus the theoretical risks of reassortment

CMB-S4 Science Book, First Edition

This book lays out the scientific goals to be addressed by the next-generation ground-based cosmic microwave background experiment, CMB-S4, envisioned to consist of dedicated telescopes at the South Pole, the high Chilean Atacama plateau and possibly a northern hemisphere site, all equipped with new superconducting cameras. CMB-S4 will dramatically advance cosmological studies by crossing critical thresholds in the search for the B-mode polarization signature of primordial gravitational waves, in the determination of the number and masses of the neutrinos, in the search for evidence of new light relics, in constraining the nature of dark energy, and in testing general relativity on large scales

The Linkage Between Neighborhood and Voluntary Association Patterns: a Comparison of Black and White Urban Populations

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68314/2/10.1177_089976407400300201.pd