91 research outputs found
Lunar-Mars Life Support Test Project
Phase 2 of the Lunar-Mars Life Support Test Project was conducted in June and July of 1996 at the NASA Johnson Space Center. The primary objective of Phase 2 was to demonstrate and evaluate an integrated physicochemical air revitalization and regenerative water recovery system capable of sustaining a human crew of four for 30 days inside a closed chamber. The crew (3 males and 1 female) was continuously present inside a chamber throughout the 30-day test. The objective of this paper was to describe crew interactions and human factors for the test. Crew preparations for the test included training and familiarization of chamber systems and accommodations, and medical and psychological evaluations. During the test, crew members provided metabolic loads for the life support systems, performed maintenance on chamber systems, and evaluated human factors inside the chamber. Overall, the four crew members found the chamber to be comfortable for the 30-day test. The crew performed well together and this was attributed in part to team dynamics, skill mix (one commander, two system experts, and one logistics lead), and a complementary mix of personalities. Communication with and support by family, friends, and colleagues were identified as important contributors to the high morale of the crew during the test. Lessons learned and recommendations for future testing are presented by the crew in this paper
Inelastic diffraction and color-singlet gluon-clusters in high-energy hadron-hadron and lepton-hadron collisions
It is proposed, that ``the colorless objects'' which manifest themselves in
large-rapidity-gap events are color-singlet gluon-clusters due to
self-organized criticality (SOC), and that optical-geometrical concepts and
methods are useful in examing the space-time properties of such objects. A
simple analytical expression for the -dependence of the inelastic single
diffractive cross section ( is the four-momentum transfer
squared) is derived. Comparison with the existing data and predictions for
future experiments are presented. The main differences and similarities between
the SOC-approach and the ``Partons in the Pomeron (Pomeron and
Reggeon)''-approach are discussed.Comment: 12 pages, 2 figure
Quantum mechanics, Furry's hypothesis and a measure of decoherence in the K^0 \bar{K}^0 system
We consider strangeness correlations of the EPR type in K^0 \bar{K}^0 pairs
created in a J^{PC} = 1^{--} state as a function of time under the hypothesis
that spontaneous decoherence takes place. We parameterize the degree of
decoherence by a factor (1-\zeta) which multiplies the quantum-mechanical
interference terms occurring in the amplitudes for like and unlike strangeness
events and discuss the dependence of this procedure on the basis chosen in the
K^0--\bar{K}^0 space to which the interference terms correspond. Consequently,
all statements about the ``decoherence parameter'' \zeta inferred from
experimental data are basis-dependent as well. We illustrate this point by
estimating the value of \zeta for the two bases {K_L, K_S} and {K^0, \bar{K}^0}
with the help of recent data of the CPLEAR experiment.Comment: 12 pages, 1 figure, revte
Proton-proton scattering above 3 GeV/c
A large set of data on proton-proton differential cross sections, analyzing
powers and the double polarization parameter A_NN is analyzed employing the
Regge formalism. We find that the data available at proton beam momenta from 3
GeV/c to 50 GeV/c exhibit features that are very well in line with the general
characteristics of Regge phenomenology and can be described with a model that
includes the rho, omega, f_2, and a_2 trajectories and single Pomeron exchange.
Additional data, specifically for spin-dependent observables at forward angles,
would be very helpful for testing and refining our Regge model.Comment: 16 pages, 19 figures; revised version accepted for publication in
EPJ
A Flow Induced Autoimmune Response and Accelerated Senescence of Red Blood Cells in Cardiovascular Devices
Red blood cells (RBCs) passing through heart pumps, prosthetic heart valves and other cardiovascular devices undergo early senescence attributed to non-physiologic forces. We hypothesized that mechanical trauma accelerates aging by deformation of membrane proteins to cause binding of naturally occurring IgG. RBCs isolated from blood of healthy volunteers were exposed to high shear stress in a viscometer or microfluidics channel to mimic mechanical trauma and then incubated with autologous plasma. Increased binding of IgG was observed indicating forces caused conformational changes in a membrane protein exposing an epitope(s), probably the senescent cell antigen of band 3. The binding of immunoglobulin suggests it plays a role in the premature sequestration and phagocytosis of RBCs in the spleen. Measurement of IgG holds promise as a marker foreshadowing complications in cardiovascular patients and as a means to improve the design of medical devices in which RBCs are susceptible to sublethal trauma.Research in this publication was supported by the National Institutes of Health Small Business Innovation Research program under award number R44HL114246 as a subcontract to the University of Oklahoma from VADovations and NIH grant R21HL132286 to DWS and TAS.
Open Access fees paid for in whole or in part by the University of Oklahoma Libraries.Ye
- …