Space station: A program overview

An overview is presented of the NASA program for the development of the Space Station. A general representation of the initial Space Station complex is shown. The Space Station goals and program objectives are briefly reviewed, as well as the program schedule. An advanced development program and program management approach are also presented

In-space technology experiments program: InSTEP

Information is given in viewgraph form on space research and technology strategy, space shuttle experiments, experiments' planning, industry/university experiments, plasma arc welding in space, and international in-space experiments

Technology development on evolutionary space station

The topics covered are presented in view graph form and include a space research and technology (R&T) mission statement and a NASA action plan. With respect to an integrated technology plan for the civil space program, the following topics are also covered: (1) an R&T strategy; (2) a NASA technology maturation strategy; (3) an Office of Space Flight (OSF) technology requirements evaluation; (4) an external technology perspectives summary; (5) a work breakdown structure; (6) critical user requirements/ strategic plan element categorization; (7) technology flight experiments; (8) proposed station paylods by thrust; and (9) an integrated traffic mode

Multicomponent flow on curved surfaces: A vielbein lattice Boltzmann approach

We develop and implement a novel finite difference lattice Boltzmann scheme to study multicomponent flows on curved surfaces, coupling the continuity and Navier-Stokes equations with the Cahn-Hilliard equation to track the evolution of the binary fluid interfaces. The standard lattice Boltzmann method relies on regular Cartesian grids, which makes it generally unsuitable to study flow problems on curved surfaces. To alleviate this limitation, we use a vielbein formalism to write down the Boltzmann equation on an arbitrary geometry, and solve the evolution of the fluid distribution functions using a finite difference method. Focussing on the torus geometry as an example of a curved surface, we demonstrate drift motions of fluid droplets and stripes embedded on the surface of such geometries. Interestingly, they migrate in opposite directions: fluid droplets to the outer side while fluid stripes to the inner side of the torus. For the latter we demonstrate that the global minimum configuration is unique for small stripe widths, but it becomes bistable for large stripe widths. Our simulations are also in agreement with analytical predictions for the Laplace pressure of the fluid stripes, and their damped oscillatory motion as they approach equilibrium configurations, capturing the corresponding decay timescale and oscillation frequency. Finally, we simulate the coarsening dynamics of phase separating binary fluids in the hydrodynamics and diffusive regimes for tori of various shapes, and compare the results against those for a flat two-dimensional surface. Our finite difference lattice Boltzmann scheme can be extended to other surfaces and coupled to other dynamical equations, opening up a vast range of applications involving complex flows on curved geometries

Civil space technology initiative

Viewgraphs are presented on earth to orbit propulsion, booster technology, an aeroassist flight experiment, robotics, remote sensing of Earth, and autonomous systems

Competitive Cross-Subsidization

Cross-subsidization arises naturally when firms with different comparative ad- vantages compete for consumers with diverse shopping patterns. Firms then face a form of co-opetition, being substitutes for one-stop shoppers and complements for multi-stop shoppers. Competition for one-stop shoppers then drives total prices down to cost, but firms subsidize weak products with the profit made on strong products. While firms and consumers would benefit from cooperation limiting cross- subsidization (e.g., through price caps), banning below-cost pricing instead increases firms’ profits at the expense of one-stop shoppers; this calls for a cautious use of below-cost pricing regulations in competitive markets

Plasma pro-atrial natriuretic peptide to estimate fluid balance during open and robot-assisted esophagectomy:a prospective observational study

Abstract Background It remains debated how much fluid should be administered during surgery. The atrial natriuretic peptide precursor proANP is released by atrial distension and deviations in plasma proANP are reported associated with perioperative fluid balance. We hypothesized that plasma proANP would decrease when the central blood volume is compromised during the abdominal part of robot-assisted hybrid (RE) esophagectomy and that a positive fluid balance would be required to maintain plasma proANP. Methods Patients undergoing RE ( n \u2009=\u200925) or open (OE; n \u2009=\u200925) esophagectomy for gastroesophageal cancer were included consecutively in this prospective observational study. Plasma proANP was determined repetitively during esophagectomy to allow for distinction between the abdominal and thoracic part of the procedure. The RE group was 15\ub0 head up tilted during the abdominal procedure. Results The blood loss was 250 (150\u2013375) (RE) and 600\ua0ml (390\u2013855) (OE) ( p \u2009=\u20090.01), but the two groups of patients were provided with a similar positive fluid balance: 1705 (1390\u20131983) vs. 1528\ua0ml (1316\u20131834) ( p \u2009=\u20090.4). However, plasma proANP decreased by 21% ( p \u2009<\u20090.01) during the abdominal part of RE carried out during moderate head-up tilt, but only by 11% ( p \u2009=\u20090.01) during OE where the patients were supine. Plasma proANP and fluid balance were correlated in the RE-group ( r \u2009=\u20090.5 (0.073\u20130.840), p \u2009=\u20090.02) and tended to correlate in the OE group ( r \u2009=\u20090.4 (\u22120.045\u20130.833), p \u2009=\u20090.08). Conclusion The results support that plasma proANP decreases when the central blood volume is compromised and suggest that an about 2200\ua0ml surplus administration of crystalloid is required to maintain plasma proANP during esophagectomy. Trial registration Clinicaltrials.gov ( NCT02077673 ). Registered retrospectively February 12 th 2014

Plasma pro-atrial natriuretic peptide to estimate fluid balance during open and robot-assisted esophagectomy:a prospective observational study

BACKGROUND: It remains debated how much fluid should be administered during surgery. The atrial natriuretic peptide precursor proANP is released by atrial distension and deviations in plasma proANP are reported associated with perioperative fluid balance. We hypothesized that plasma proANP would decrease when the central blood volume is compromised during the abdominal part of robot-assisted hybrid (RE) esophagectomy and that a positive fluid balance would be required to maintain plasma proANP. METHODS: Patients undergoing RE (n = 25) or open (OE; n = 25) esophagectomy for gastroesophageal cancer were included consecutively in this prospective observational study. Plasma proANP was determined repetitively during esophagectomy to allow for distinction between the abdominal and thoracic part of the procedure. The RE group was 15° head up tilted during the abdominal procedure. RESULTS: The blood loss was 250 (150–375) (RE) and 600 ml (390–855) (OE) (p = 0.01), but the two groups of patients were provided with a similar positive fluid balance: 1705 (1390–1983) vs. 1528 ml (1316–1834) (p = 0.4). However, plasma proANP decreased by 21% (p < 0.01) during the abdominal part of RE carried out during moderate head-up tilt, but only by 11% (p = 0.01) during OE where the patients were supine. Plasma proANP and fluid balance were correlated in the RE-group (r = 0.5 (0.073–0.840), p = 0.02) and tended to correlate in the OE group (r = 0.4 (−0.045–0.833), p = 0.08). CONCLUSION: The results support that plasma proANP decreases when the central blood volume is compromised and suggest that an about 2200 ml surplus administration of crystalloid is required to maintain plasma proANP during esophagectomy. TRIAL REGISTRATION: Clinicaltrials.gov (NCT02077673). Registered retrospectively February 12(th) 2014