Highly alkylated cyclohexanes. X-Ray crystal structures, force-field calculations, and conformations of cis/trans-1,4-disubstituted cyclohexane isomers

The structures of mesylated cis- and trans-tetramethylshisool cis- 2 and trans-2 have been elucidated by single-crystal X-ray techniques. In cis-2 the isopropenyl group adopts an axial position in the crystal, and the structural data obtained are in good agreement with those from force-field calculations. In trans-2 the two rotamers arising from rotation of the isopropenyl group were assigned by NOE measurements. Comparison of the spectroscopic data with those of other tetramethyllimonene derivatives showed that these can be classified into compounds with preferred equatorial and preferred axial position of the isopropenyl group

Analysis of the performance of the drive system and diffuser of the Langley unitary plan wind tunnel

A broad program was initiated at the Langley Research Center in 1973 to reduce the energy consumption of the laboratory. As a part of this program, the performance characteristics of the Unitary Plan Wind Tunnel were reexamined to determine if potential methods for incresing the operating efficiencies of the tunnel could be formulated. The results of that study are summarized. The performance characteristics of the drive system components and the variable-geometry diffuser system of the tunnel are documented and analyzed. Several potential methods for reducing the energy requirements of the facility are discussed

As Investigation at Mach Numbers of 1.41 and 2.01 of the Aerodynamic Characteristics of an 0.025-scale Model of the MX-1712

An investigation of the aerodynamic characteristics of an 0.025-scale model of the MX-1712 configuration has been conducted in the Langley 4- by 4-foot supersonic pressure tunnel. The tests were performed at Mach numbers of 1.41 and 2.01 at a Reynolds number of approximately 2.6 x 10(exp 6) based on the wing mean aerodynamic chord The MX-1712 is a proposed swept-wing, jet-powered supersonic bomber aircraft. The wing is of aspect ratio 3.5, taper ratio 0.2, and thickness ratio 5.5 percent (streamwise) and has 47deg sweep of the quarter-chord line. The longitudinal and lateral force characteristics of the model and various combinations of its components, including several nacelle installations, were investigated. The effects of a modified wing, two horizontal tail positions, and a shortened fuselage were also studied. The results obtained from these investigations are presented in this report. The aerodynamic investigation of this model disclosed no unusual stability characteristics or Mach number effects. The choice of nacelle installations appears to be a major decision, one greatly affecting the performance of the airplane, At M = 1.41 and C(sub L) = 0.1, the buried nacelles increased the drag of the basic model by 9 percent, while the best pod nacelles increased the drag of the basic model by 27 percent

Strateški pristup suzbijanju krađa vozila (studija slučaja)

Strateški pristup suzbijanju krađa vozila (studija slučaja

High-speed Civil Transport Aircraft Emissions

Estimates are given for the emissions from a proposed high speed civil transport (HSCT). This advanced technology supersonic aircraft would fly in the lower stratosphere at a speed of roughly Mach 1.6 to 3.2 (470 to 950 m/sec or 920 to 1850 knots). Because it would fly in the stratosphere at an altitude in the range of 15 to 23 km commensurate with its design speed, its exhaust effluents could perturb the chemical balance in the upper atmosphere. The first step in determining the nature and magnitude of any chemical changes in the atmosphere resulting from these proposed aircraft is to identify and quantify the chemically important species they emit. Relevant earlier work is summarized, dating back to the Climatic Impact Assessment Program of the early 1970s and current propulsion research efforts. Estimates are provided of the chemical composition of an HSCT's exhaust, and these emission indices are presented. Other aircraft emissions that are not due to combustion processes are also summarized; these emissions are found to be much smaller than the exhaust emissions. Future advances in propulsion technology, in experimental measurement techniques, and in understanding upper atmospheric chemistry may affect these estimates of the amounts of trace exhaust species or their relative importance

Scripture in the Theologies of W. Pannenberg and D. G. Bloesch: an Investigation and Assessment of its Origin, Nature, and Use

Scripture has played an authoritative role in Christian theology for centuries and has been at the heart of Protestant theology from its beginning. The rise of modern historical criticism, however, has led to a crisis at this very foundation of Protestant theology. In this context this dissertation seeks to set forth, analyze, compare, and evaluate theconcept of Scripture in the theologies of two contemporary Protestant systematic theologians who represent significantly different concepts of Scripture: Wolfhart Pannenberg and Donald G. Bloesch. Chapter 1 provides a brief introduction, delineates the objectives, research methodology, and delimitations of the study. This is followed in chapter 2, by an issue-oriented overview of the concepts of Scripture in theology, that have surfaced from the time of the Protestant Reformation onward. This oveview describes the positions of important theological representatives who significantly influenced the concept of Scripture in church history up to the present time. Chapter 3 focuses on Wolfgang Pannenberg\u27s concept of Scripture by first describing his understanding of Scripture\u27s origin, nature, and use; then the second part of this chapter analyzes the theological and anthropological presuppositions which have influenced Pannenberg\u27s concept of Scripture. Chapter 4 treats Donald G. Bloesch\u27s view of Scripture, following the same pattern as in chapter 3. Chapter 5 compares the positions of Pannenberg and Bloesch, evaluating them on the basis of internal consistency. The assumptions and presuppositions upon which the respective positions seem to rest are also taken into consideration. It appears that despite the fundamentally different starting points and other significant differences, Pannenberg and Bloesch nevertheless reveal a number of surprising similarities in their views of Scripture. This would seem to suggest that for both theologians the concept of Scripture is determined ultimately by presuppositions that are derived and shaped extra scripturam