Compound cycle engine for helicopter application

The Compound Cycle Engine (CCE) is a highly turbocharged, power compounded, ultra-high power density, light-weight diesel engine. The turbomachinery is similar to a moderate pressure ratio, free power turbine engine and the diesel core is high speed and a low compression ratio. This engine is considered a potential candidate for future military light helicopter applications. This executive summary presents cycle thermodynamic (SFC) and engine weight analyses performed to establish general engine operating parameters and configuration. An extensive performance and weight analysis based on a typical two hour helicopter (+30 minute reserve) mission determined final conceptual engine design. With this mission, CCE performance was compared to that of a T-800 class gas turbine engine. The CCE had a 31% lower-fuel consumption and resulted in a 16% reduction in engine plus fuel and fuel tank weight. Design SFC of the CCE is 0.33 lb-HP-HR and installed wet weight is 0.43 lbs/HP. The major technology development areas required for the CCE are identified and briefly discussed

Evaluation of a biopolymer matrix for cell based bone repair

Autogenous bone grafts are often associated with unpredictable success rates and donor site morbidity. There is clear medical need for cost-effective bone graft material that overcomes these short-comings. Aim: To test a thermally stable, macro-porous collagen scaffold, DuraGen® for bone repair and study its ability to stimulate healing of critical size defects in rat calvaria engrafted with Mesenchymal Stem Cells(MSCs). Methods: Craniotomy defects, 8.9mm diameter were created in 28 adult Sprague-Dawley rats, randomly divided into four groups, 6-Empty(E), 6-Collagen only(C), 8-Collagen+MSCs(C+M), 8-Collagen+rhBMP-2(C+B). Two transgenic rats served as stromal cell donors by means of femoral marrow lavage. Results: Bone repair at 28 days was measured using radiographs and histology. Histology showed mean bone fill of 9.25%(10.82), 19.07%(17.38), 44.21%(3.93) and 66.06%(15.08) respectively. Statistical analysis demonstrated significant differences between: E & C, C & C+M, C+B; none between C+M & C+B. Conclusion: This study clearly displays osteogenic properties of collagen scaffold implanted with MSCs

The subscale orbital fluid transfer experiment

The Subscale Orbital Fluid Transfer Experiment (SOFTE) is a planned Shuttle Orbiter fluid transfer experiment. CASP (Center for Advanced Space Propulsion) performed certain aspects of the conceptual design of this experiment. The CASP work consisted of the conceptual design of the optical system, the search for alternative experimental fluids, the determination of the flow meter specifications and the examination of materials to use for a bladder that will empty one of the tanks in the experiment

Determinants of condom use among currently married men in Zambia

HIV is one of the leading health threats and cause of morbidity and mortality in Zambia. Among many preventive measures, condom use is the most effective methods of preventing HIV. The aim of this study was to investigate factors associated with condom use among currently married men in Zambia. Secondary data from the 2013 Zambia Demographic Health Survey was used. Results from binary logistic regression analysis showed that condom use is associated with being young (β = -0.71, p < 0.001), being rich (β = 0.25, p < 0.05), paying for sex (β = 0.42, p < 0.001), perceiving risk of contracting HIV (β = 0.38, p < 0.001), and believing in the efficacy of condom use as a protective measure against HIV (β = 0.24, p < 0.01). Condom use in Zambia is associated with socio-demographic characteristics and habits of adult males. Therefore, prevention measures aimed at increased the use of male condoms should integrate social demographic characteristics and habits of adult males to be effective.Keywords: Condom use, married men, determinants, Zambi

A Memorial for William V. Sliter

William V. (Bill) Sliter, an internationally known micropaleontologist and research geologist for the U.S. Geological Survey, passed away suddenly, October, 1997, while talking to a colleague in his office. In his honor, B. Huber, T. Bralower, and M. Leckie organized a keynote symposium ‘‘Paleoecological and Geochemical Signatures of Cretaceous Anoxic Events’’ at the 1998 annual meeting of the Geological Society of America in Toronto, Canada. This theme issue of the Journal of Foraminiferal Research contains the published papers from the symposium and is dedicated to his memory

A Memorial for William V. Sliter

William V. (Bill) Sliter, an internationally known micropaleontologist and research geologist for the U.S. Geological Survey, passed away suddenly, October, 1997, while talking to a colleague in his office. In his honor, B. Huber, T. Bralower, and M. Leckie organized a keynote symposium ‘‘Paleoecological and Geochemical Signatures of Cretaceous Anoxic Events’’ at the 1998 annual meeting of the Geological Society of America in Toronto, Canada. This theme issue of the Journal of Foraminiferal Research contains the published papers from the symposium and is dedicated to his memory