Twin Web Disk — A Step Beyond Convention

1998 ◽  
Author(s):  
Ronald R. Cairo ◽  
Kathleen A. Sargent
Keyword(s):  
Air Force ◽  
State Of The Art ◽  
Minimum Weight ◽  
Turbine Rotor ◽  
Innovative Design ◽  
Composite Ring ◽  
Rotor Design ◽  
Material Component ◽  
History Of ◽  
Concept Validation

This paper will discuss a study of an innovative design for an advanced turbine rotor, that could have a great impact on future engines. The design challenge is to provide a minimum weight turbine rotor system that can withstand beyond state-of-the-art levels of AN2 (turbine annulus area multiplied by speed squared). An AN2 limit has been reached for High Pressure Turbine (HPT) disks configured in conventional (single web) geometry with state-of-the-art nickel alloys. The problem has reached the point where increased AN2 has been declared a “Break-Through” technology. The twin-web disk has the potential to provide this break through. This paper will present the history of this turbine rotor design, analytical results, material/component processing and concept validation results. All work was performed under an Air Force sponsored program entitled Composite Ring Reinforced Turbine (CRRT).

Twin Web Disk: A Step Beyond Convention

2002 ◽  
Vol 124 (2) ◽  
pp. 298-302 ◽  
Author(s):  
R. R. Cairo ◽  
K. A. Sargent
Keyword(s):  
Air Force ◽  
State Of The Art ◽  
Minimum Weight ◽  
Turbine Rotor ◽  
Innovative Design ◽  
Composite Ring ◽  
Rotor Design ◽  
Material Component ◽  
History Of ◽  
Concept Validation

This paper will discuss a study of an innovative design for an advanced turbine rotor that could have a great impact on future engines. The design challenge is to provide a minimum weight turbine rotor system that can withstand beyond state-of-the-art levels of AN2 (turbine annulus area multiplied by speed squared). An AN2 limit has been reached for high-pressure turbine (HPT) disks configured in conventional (single web) geometry with state-of-the-art nickel alloys. The problem has reached the point where increased AN2 has been declared a “break-through” technology. The twin-web disk has the potential to provide this break through. This paper will present the history of this turbine rotor design, analytical results, material/component processing, and concept validation results. All work was performed under an Air Force sponsored program entitled “Composite Ring Reinforced Turbine” (CRRT).

Biological NMR Spectroscopy

1997 ◽  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Nmr Spectroscopy ◽  
Magnetic Resonance ◽  
Magnetic Resonance Spectroscopy ◽  
State Of The Art ◽  
Critical Assessment ◽  
Resonance Spectroscopy ◽  
History Of ◽  
Structure Of Proteins

This book presents a critical assessment of progress on the use of nuclear magnetic resonance spectroscopy to determine the structure of proteins, including brief reviews of the history of the field along with coverage of current clinical and in vivo applications. The book, in honor of Oleg Jardetsky, one of the pioneers of the field, is edited by two of the most highly respected investigators using NMR, and features contributions by most of the leading workers in the field. It will be valued as a landmark publication that presents the state-of-the-art perspectives regarding one of today's most important technologies.

Computers in Geology - 25 Years of Progress

1994 ◽  
Keyword(s):  
Computer Modeling ◽  
Quantitative Methods ◽  
State Of The Art ◽  
International Association ◽  
Mathematical Geology ◽  
25Th Anniversary ◽  
The Earth ◽  
Wide Range ◽  
History Of ◽  
Mapping Techniques

This volume vividly demonstrates the importance and increasing breadth of quantitative methods in the earth sciences. With contributions from an international cast of leading practitioners, chapters cover a wide range of state-of-the-art methods and applications, including computer modeling and mapping techniques. Many chapters also contain reviews and extensive bibliographies which serve to make this an invaluable introduction to the entire field. In addition to its detailed presentations, the book includes chapters on the history of geomathematics and on R.G.V. Eigen, the "father" of mathematical geology. Written to commemorate the 25th anniversary of the International Association for Mathematical Geology, the book will be sought after by both practitioners and researchers in all branches of geology.

scholarly journals Molecular and Cellular Mechanisms Underlying Temperature-Dependent Sex Determination in Turtles

2021 ◽  
pp. 1-9
Author(s):  
Horacio Merchant-Larios ◽  
Verónica Díaz-Hernández ◽  
Diego Cortez
Keyword(s):  
Animal Models ◽  
Sex Determination ◽  
Incubation Temperature ◽  
State Of The Art ◽  
Current Understanding ◽  
Temperature Dependent ◽  
Cellular Mechanisms ◽  
Male Phenotype ◽  
History Of ◽  
Reptilian Species

The discovery in mammals that fetal testes are required in order to develop the male phenotype inspired research efforts to elucidate the mechanisms underlying gonadal sex determination and differentiation in vertebrates. A pioneer work in 1966 that demonstrated the influence of incubation temperature on sexual phenotype in some reptilian species triggered great interest in the environment’s role as a modulator of plasticity in sex determination. Several chelonian species have been used as animal models to test hypotheses concerning the mechanisms involved in temperature-dependent sex determination (TSD). This brief review intends to outline the history of scientific efforts that corroborate our current understanding of the state-of-the-art in TSD using chelonian species as a reference.

scholarly journals Introduction

1990 ◽  
Vol 30 (4) ◽  
pp. 487-492 ◽  
Author(s):  
Carl F. Kaestle
Keyword(s):  
State Of The Art ◽  
History Of Education ◽  
The State ◽  
Special Issue ◽  
Research Papers ◽  
History Of

The History of Education Quarterly has done it again. Despite many scholars' previous attempts to summarize the state of the art in historical studies of literacy, this special issue will now be the best, up-to-date place for a novice to start. It should be required reading for everyone interested in this subfield. The editors have enlisted an impressive roster of prominent scholars in the field, and these authors have provided us with an excellent array of synthetic reviews, methodological and theoretical discussions, and exemplary research papers.

History of Mathematics in the Islamic World: The Present State of the Art

1985 ◽  
Vol 19 (1) ◽  
pp. 9-33 ◽  
Author(s):  
J. L. Berggren
Keyword(s):  
Present State ◽  
State Of The Art ◽  
History Of Mathematics ◽  
Islamic Culture ◽  
Islamic World ◽  
History Of ◽  
The Subject ◽  
Mathematical Sciences ◽  
Islamic Mathematics

In Recent Years, many discoveries in the history of Islamic mathematics have not been reported outside the specialist literature, even though they raise issues of interest to a larger audience. Thus, our aim in writing this survey is to provide to scholars of Islamic culture an account of the major themes and discoveries of the last decade of research on the history of mathematics in the Islamic world. However, the subject of mathematics comprised much more than what a modern mathematician might think of as belonging to mathematics, so our survey is an overview of what may best be called the “mathematical sciences” in Islam; that is, in addition to such topics as arithmetic, algebra, and geometry we will also be interested in mechanics, optics, and mathematical instruments.

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