Compound cycle engine program

The Compound Cycle Engine (CCE) is a highly turbocharged, power compounded power plant which combines the lightweight pressure rise capability of a gas turbine with the high efficiency of a diesel. When optimized for a rotorcraft, the CCE will reduce fuel burned for a typical 2 hr (plus 30 min reserve) mission by 30 to 40 percent when compared to a conventional advanced technology gas turbine. The CCE can provide a 50 percent increase in range-payload product on this mission. A program to establish the technology base for a Compound Cycle Engine is presented. The goal of this program is to research and develop those technologies which are barriers to demonstrating a multicylinder diesel core in the early 1990's. The major activity underway is a three-phased contract with the Garrett Turbine Engine Company to perform: (1) a light helicopter feasibility study, (2) component technology development, and (3) lubricant and material research and development. Other related activities are also presented

Light curves for bump Cepheids computed with a dynamically zoned pulsation code

The dynamically zoned pulsation code developed by Castor, Davis, and Davison was used to recalculate the Goddard model and to calculate three other Cepheid models with the same period (9.8 days). This family of models shows how the bumps and other features of the light and velocity curves change as the mass is varied at constant period. The use of a code that is capable of producing reliable light curves demonstrates that the light and velocity curves for 9.8 day Cepheid models with standard homogeneous compositions do not show bumps like those that are observed unless the mass is significantly lower than the 'evolutionary mass.' The light and velocity curves for the Goddard model presented here are similar to those computed independently by Fischel, Sparks, and Karp. They should be useful as standards for future investigators

Spectral variability in early-type binary X-ray systems

Theoretical models for the ionization of trace elements in a strong stellar wind by a compact binary X-ray source and for the resulting orbital phase dependence of the emergent soft X-ray spectra and the profiles of ultraviolet resonance lines are presented. Model results agree qualitatively with the X-ray and ultraviolet spectra of the system 4U 0900-40/HD 77581 and explain the suppression of the absorption profiles of the Si IV upsilon 1394 and C IV upsilon 1548 lines when the X-ray sources is in front of the star. The model predicts that the absorption profiles of the N V upsilon 1239 and O VI upsilon 1032 lines will be enhanced rather than suppressed during this orbital phase. We predict phase-dependent linear polarization in the resonance lines profiles. Future observations of these phase dependent effects in early-type binary X-ray systems may be used to investigate the dynamics of stellar winds and their interactions with the X-ray source

Hyaluronic acid in human synovial effusions; A sensitive indicator of altered connective tissue cell function during inflammation

No Abstract.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/37705/1/1780090606_ftp.pd

Preliminary evaluation of a compound cycle engine for shipboard gensets

The results of a thermodynamic cycle (SFC) and weight analysis performed to establish engine configuration, size, weight and performance are reported. Baseline design configuration was a 2,000 hour MTBO Compound Cycle Engine (CCE) for a helicopter application. The CCE configuration was extrapolated out to a 10,000 MTBO for a shipboard genset application. The study showed that an advanced diesel engine design (CCE) could be substantially lighter and smaller (79% and 82% respectively) than todays contemporary genset diesel engine. Although the CCE was not optimized, it had about a 7% reduction in mission fuel consumption over today's genset diesels. The CCE is a turbocharged, power-compounded, high power density, low-compression ratio diesel engine. Major technology development areas are presented

Effects of calorie restriction and IGF-1 receptor blockade on the progression of 22Rv1 prostate cancer xenografts.

Calorie restriction (CR) inhibits prostate cancer progression, partially through modulation of the IGF axis. IGF-1 receptor (IGF-1R) blockade reduces prostate cancer xenograft growth. We hypothesized that combining calorie restriction with IGF-1R blockade would have an additive effect on prostate cancer growth. Severe combined immunodeficient mice were subcutaneously injected with 22Rv1 cells and randomized to: (1) Ad libitum feeding/intraperitoneal saline (Ad-lib); (2) Ad-lib/20 mg/kg twice weekly, intraperitoneal ganitumab [anti-IGF-1R antibody (Ad-lib/Ab)]; (3) 40% calorie restriction/intraperitoneal saline (CR); (4) CR/ intraperitoneal ganitumab, (CR/Ab). CR and ganitumab treatment were initiated one week after tumor injection. Euthanasia occurred 19 days post treatment. Results showed that CR alone decreased final tumor weight, plasma insulin and IGF-1 levels, and increased apoptosis. Ganitumab therapy alone reduced tumor growth but had no effect on final tumor weight. The combination therapy (CR/Ab) further decreased final tumor weight and proliferation, increased apoptosis in comparison to the Ad-lib group, and lowered plasma insulin levels relative to the Ad-lib and Ad-lib/Ab groups. Tumor AKT activation directly correlated with plasma IGF-1 levels. In conclusion, whereas ganitumab therapy modestly affected 22Rv1 tumor growth, combining IGF-1R blockade with calorie restriction resulted in a significant decrease in final tumor weight and improved metabolic profile

Improved velocity law parameterization for hot star winds

The velocity law of hot star winds is usually parameterized via the so-called beta velocity law. Although this parameterization stems from theoretical considerations, it is not the most accurate description of the wind velocity law that follows from hydrodynamical calculations. We show that the velocity profile of our hydrodynamical wind models is described much better by polynomial approximation. This approximation provides a better fit than the beta velocity law already for the same number of free parameters.Comment: 3 pages, 2 figures, accepted for publication in Astronomy & Astrophysic

Aspherical Explosion Models for SN 1998bw/GRB 980425

The recent discovery of the unusual supernova SN1998bw and its apparent correlation with the gamma-ray burst GRB 980425 has raised new issues concerning both the GRB and supernovae. Although the spectra resemble those of TypeIc supernovae, there are distinct differences at early times and SN1998bw appeared to be unusually bright and red at maximum light. The apparent expansion velocities inferred by the Doppler shift of (unidentified) absorption features appeared to be high, making SN1998bw a possible candidate for a "hypernova" with explosion energies between 20 and 50E51 erg and ejecta masses in excess of 6 - 15 M_o. Based on light curve calculations for aspherical explosions and guided by the polarization observations of "normal" SNIc and related events, we present an alternative picture that allows SN1998bw to have an explosion energy and ejecta mass consistent with core collapse supernovae (although at the 'bright' end). We show that the LC of SN1998bw can be understood as result of an aspherical explosion along the rotational axis of a basically spherical, non-degenerate C/O core of massive star with an explosion energy of 2foe and a total ejecta mass of 2 M_o if it is seen from high inclinations with respect to the plane of symmetry. In this model, the high expansion velocities are a direct consequence of an aspherical explosion which, in turn, produces oblate iso-density contours. It suggests that the fundamental core-collapse explosion process itself is strongly asymmetric.Comment: 12 pages, 8 figures, latex, aas2pp4.sty, submitted to Ap

Bryostatin-1 vs. TPPB: Dose-Dependent APP Processing and PKC-α, -δ, and -ε Isoform Activation in SH-SY5Y Neuronal Cells

Activation of the α-secretase processing pathway of amyloid precursor protein (APP) is recognized as an important mechanism which diverts APP processing from production of beta-amyloid (Aβ) to non toxic sAPPα, decreasing Alzheimer’s disease (AD) plaque formation and AD-associated cognitive deficits. Two potent classes of PKC modulators can activate the α-secretase pathway, the benzo/indolactams and bryostatin/bryologues. While both modulate PKC-dependent APP processing, no direct comparisons of their relative pharmacological potencies have been accomplished which could assist in the development of AD therapies. In this study, we measured the activation of α-secretase APP processing and PKC-α, -δ, and -ε induced by the benzolactam-APP modulator TPPB and bryostatin-1 in the neuroblastoma cell line SH-SY5Y which expresses APP and α- and β-secretase processing mechanisms. Bryostatin-1 produced a more rapid, potent, and sustained activation of α-secretase APP processing than TPPB and selectively activated PKC-δ and PKC-ε. Although TPPB also activated α-secretase, its potency was approximately 10- to 100-fold lower, possibly reflecting lower PKC-δ and -ε activation. Because bryostatin-1 is a highly potent PKC-δ and -ε activator which activates α-secretase APP processing, further characterization of bryostatin-1/bryologues may help refine their use as important tools for the clinical management of AD