Engine diagnostics program: CF6-50 engine performance deterioration

Cockpit cruise recordings and test cell data in conjunction with hardware inspection results from airline overhaul shops were analyzed to define the extent and magnitude of performance deterioration of the General Electric CF6-50 high bypass turbofan engine. The magnitude of short term deterioration was isolated from the long term, and the individual damage mechanisms that were the cause for the majority of the performance deterioration was identified. It was determined that the long term engine performance deterioration characteristics were different for the 3 aircraft types currently powered by the CF6-50 engine, but these differences were due to operational considerations (flight length and takeoff derate) and not to differences associated with the aircraft type. Unrestored losses, that is, performance deterioration which remains after engine refurbishment, represents over 70 percent of the total performance deterioration at engine shop visit. Superficial damage, such as, increased surface roughness, leading edge shape changes on airfoils, and increases in the average clearances between rotating and stationary components is the major contributor to these losses. Seventy one percent of the unrestored losses are cost effective to restore, and if implemented could reduce fuel consumed by CF6-50 engines by 26 million gallons in 1980

CF6-6D engine short-term performance deterioration

Studies conducted as part of the NASA-Lewis CF6 jet engine diagnostics program are summarized. An 82-engine sample of DC-10-10 aircraft engine checkout data that were gathered to define the extent and magnitude of CF6-6D short term performance deterioration were analyzed. These data are substantiated by the performance testing and analytical teardown of CF6-6D short term deterioration engine serial number (ESN) 451507

CF6-6D engine performance deterioration

Cruise cockpit recordings and test cell performance data in conjunction with hardware inspection data from airline overhaul shops were analyzed to define the extent and magnitude of performance deterioration of the General Electric CF6-6D model engine. These studies successfully isolated short-term deterioration from the longer term, and defined areas where a significant reduction in aircraft energy requirements for the 1980's can be realized. Unrestored losses which remain after engine refurbishment represent over 70% of the loss at engine shop visit. Sixty-three percent of the unrestored losses are cost-effective to restore which could reduce fuel consumed by CF6-6D engines in 1980 by 10.9 million gallons

Combined Shape and Parameter Identification Applied to a Porous Media Simulation

For material parameter estimation as well as shape identification a variety of research and commercial software exists. These tools are often integrated directly into an FEM program or use the FEM solver as a subroutine. However, the two problems are always considered as separate tasks which are solved by separate software packages. When simulating structured specimens, the considered domain often consists of different material types. These are modeled using different material domains. Frequently, the material parameters and the shape of the material domains are unknown. As both components considerably influence the simulation results, separate identification yields poor results. The inhouse identification and optimization software SPC-Opt developed at the department of Solid Mechanics at Chemnitz University of Technology is capable of solving shape and parameter identification simultaneously. Here, the key concept is an abstract formulation of parameters as variables that influence FEM computations. In this paper, the general design and algorithms are presented. Moreover, the application is demonstrated on an academic example using a simple porous media constitutive model

Manifestation of the Hofstadter butterfly in far-infrared absorption

The far-infrared absorption of a two-dimensional electron gas with a square-lattice modulation in a perpendicular constant magnetic field is calculated self-consistently within the Hartree approximation. For strong modulation and short period we obtain intra- and intersubband magnetoplasmon modes reflecting the subbands of the Hofstadter butterfly in two or more Landau bands. The character of the absorption and the correlation of the peaks to the number of flux quanta through each unit cell of the periodic potential depends strongly on the location of the chemical potential with respect to the subbands, or what is the same, on the density of electrons in the system.Comment: RevTeX file + 4 postscript figures, to be published Phys. Rev. B Rapid Com

67/09/27 Brief of American Civil Liberties Union, American Civil Liberties Union of Ohio, and New York Civil Liberties Union, Amici Curiae

The American Civil Liberties Union (ACLU), ACLU of New York and New York Civil Liberties Union\u27s Amici Curiae Brief arguing against the stop-and-frisk practice as seen in Terry v. Ohio and Chilton v. Ohio, Peters v. New York, and Sibron v. New York

67/09/27 Brief of American Civil Liberties Union, American Civil Liberties Union of Ohio, and New York Civil Liberties Union, Amici Curiae

The American Civil Liberties Union (ACLU), ACLU of New York and New York Civil Liberties Union\u27s Amici Curiae Brief arguing against the stop-and-frisk practice as seen in Terry v. Ohio and Chilton v. Ohio, Peters v. New York, and Sibron v. New York

Stereotactic, single-dose irradiation of stage I non-small cell lung cancer and lung metastases

BACKGROUND: We prospectively reviewed response rates, local control, and side effects after non-fractionated stereotactic high single-dose body radiation therapy for lung tumors. METHODS: Fifty-eight patients underwent radiosurgery involving single-dose irradiation. With 25 patients, 31 metastases in the lungs were irradiated; with each of 33 patients, stage I non-small cell lung cancer (NSCLC) was subject to irradiation. The standard dose prescribed to the isocenter was 30 Gy with an axial safety margin of 10 mm and a longitudinal safety margin of 15 mm. The planning target volume (PTV) was defined using three CT scans with reference to the phases of respiration so that the movement span of the clinical target volume (CTV) was enclosed. RESULTS: The volume of the metastases (CTV) varied from 2.8 to 55.8 cm(3 )(median: 6.0 cm(3)) and the PTV varied from 12.2 to 184.0 cm(3 )(median: 45.0 cm(3)). The metastases ranged from 0.7 to 4.5 cm in largest diameter. The volume of the bronchial carcinomas varied from 4.2 to 125.4 cm(3)(median: 17.5 cm(3)) and the PTV from 15.6 to 387.3 cm(3 )(median: 99.8 cm(3)). The bronchial carcinomas ranged from 1.7 to 10 cm in largest diameter. Follow-up periods varied from 6.8 to 63 months (median: 22 months for metastases and 18 months for NSCLC). Local control was achieved with 94% of NSCLC and 87% of metastases. No serious symptomatic side effects were observed. According to the Kaplan-Meier method the overall survival probability rates of patients with lung metastases were as follows: 1 year: 97%, 2 years: 73%, 3 years: 42%, 4 years: 42%, 5 years: 42% (median survival: 26 months); of those with NSCLC: 1 year: 83%, 2 years: 63%, 3 years: 53%, 4 years: 39%: (median survival: 20.4 months). CONCLUSION: Non-fractionated single-dose irradiation of metastases in the lungs or of small, peripheral bronchial carcinomas is an effective and safe form of local treatment and might become a viable alternative to invasive techniques

Steps for Warner-Bratzler Shear Force Assessment of Cooked Beef Longissimus Steaks at South Dakota State University

This article outlines the current protocol for measuring tenderness of cooked beef longissiumus steaks at South Dakota State University using a Warner-Bratzler shear machine

A genome-wide association study on hematopoietic stem cell transplantation reveals novel genomic loci associated with transplant outcomes

Copyright \ua9 2024 Rosenberger, Crossland, Dressel, Kube, Wolff, Wulf, Bickeb\uf6ller, Dickinson and Holler.Introduction: Data on genomic susceptibility for adverse outcomes after hematopoietic stem cell transplantation (HSCT) for recipients are scarce. Methods: We performed a genome wide association study (GWAS) to identify genes associated with survival/mortality, relapse, and severe graft-versus-host disease (sGvHD), fitting proportional hazard and subdistributional models to data of n=1,392 recipients of European ancestry from three centres. Results: The single nucleotide polymorphism (SNP) rs17154454, intronic to the neuronal growth guidant semaphorin 3C gene (SEMA3C), was genome-wide significantly associated with event-free survival (p=7.0x10-8) and sGvHD (p=7.5x10-8). Further associations were detected for SNPs in the Paxillin gene (PXN) with death without prior relapse or sGvHD, as well as for SNPs of the Plasmacytoma Variant Translocation 1 gene (PVT1, a long non-coding RNA gene), the Melanocortin 5 Receptor (MC5R) gene and the WW Domain Containing Oxidoreductase gene (WWOX), all associated with the occurrence of sGvHD. Functional considerations support the observed associations. Discussion: Thus, new genes were identified, potentially influencing the outcome of HSCT