The potential hazard of staphylococci and micrococci to human subjects in a life support systems evaluator while on a simulated GT-7 mission Final report, 19 Sep. - 1 Nov. 1965

Potential hazard of staphylococci and micrococci to human subjects in life support system

The potential hazard of staphylococci and micrococci to human subjects in a life support systems evaluator and on a diet of precooked freeze dehydrated foods

Distribution, and hazards of indigenous microbial populations in humans during prolonged space flight simulatio

Experimental studies of hypersonic boundary-layer transition and effects of wind tunnel disturbances

Boundary layer transition data on cones and free stream disturbance levels were measured in a hypersonic wind tunnel and Mach 8 variable density hypersonic tunnel. Transition data were obtained by using different conical models and techniques for detecting the location of transition. The disturbance levels were measured by using hot wire anemometry and pressure transducers. The transition Reynolds numbers obtained from the tests correlated well when the fluctuating pressures measured at the surface of conical models were used as a correlating parameter

A laboratory study into a novel, retrofittable rainwater harvesting system

Aims: To establish the system characteristics of a novel rainwater harvesting system.Study Design: A laboratory test rig was used to assess the selected technology.Place and Duration of Study: University of Exeter, Centre for Water Systems between June 2014 and May 2015.Methodology: Previous research has identified that systems should have: 1) reduced capital costs, 2) reduced operational costs and 3) increased ease of retrofitting. To investigate the system’s ability to address these requirements, two full-scale laboratory test rigs have been used to assess flow and power consumption characteristics under a range of installation scenarios.Results: The system was identified to have a mean power consumption of 0.12kWh/m3 during a one hour pump test. Electrical costs were found to increase when the power consumption of the 11W control board was taken into account.Conclusion: Subject to reduction of the standby power consumption of the controller, the novel RWH system assessed in this study has potential to provide non-potable water supplies to households in the UK at a lower power consumption rate than existing water supply systems identified in the literature

US Air Force Materiel Command`s second round ECAMP results

The United States Air Force`s Environmental Compliance Assessment and Management Program (ECAMP) is a process to improve Air Force environmental compliance, management, and programmatic support. Midway into the third round of Command-initiated (external) ECAMP evaluations for its fourteen Air Logistics and Systems Centers, the Air Force Material Command (AFMC) is continuing to identify the root causes of instances of environmental noncompliance. The AFMC initiated an analysis of all negative findings identified during the second round of external ECAMP evaluations (June 1991 to January 1993). Presented here is a summary of the analysis with emphasis on trends and root causes

Statistical Estimation of Orbital Debris Populations with a Spectrum of Object Size

Orbital debris is a real concern for the safe operations of satellites. In general, the hazard of debris impact is a function of the size and spatial distributions of the debris populations. To describe and characterize the debris environment as reliably as possible, the current NASA Orbital Debris Engineering Model (ORDEM2000) is being upgraded to a new version based on new and better quality data. The data-driven ORDEM model covers a wide range of object sizes from 10 microns to greater than 1 meter. This paper reviews the statistical process for the estimation of the debris populations in the new ORDEM upgrade, and discusses the representation of large-size (greater than or equal to 1 m and greater than or equal to 10 cm) populations by SSN catalog objects and the validation of the statistical approach. Also, it presents results for the populations with sizes of greater than or equal to 3.3 cm, greater than or equal to 1 cm, greater than or equal to 100 micrometers, and greater than or equal to 10 micrometers. The orbital debris populations used in the new version of ORDEM are inferred from data based upon appropriate reference (or benchmark) populations instead of the binning of the multi-dimensional orbital-element space. This paper describes all of the major steps used in the population-inference procedure for each size-range. Detailed discussions on data analysis, parameter definition, the correlation between parameters and data, and uncertainty assessment are included

Daily reduction of oral malodor with the use of a sonic tongue brush combined with an antibacterial tongue spray in a randomized cross-over clinical investigation

Abstract The objective of this clinical investigation was to test the effectiveness on breath odor of a newly designed sonic tongue brush (TongueCare+, TC). It consists of a soft silicone brush optimally designed based on the tongue's anatomy to remove bacterial biofilm from the tongue's complex surface, and it is coupled with a sonic power toothbrush handle. TC was used in combination with an antibacterial tongue spray (BreathRx, BRx) containing 0.09% cetylpyridinium chloride and 0.7% zinc gluconate. A total of 21 participants with oral malodor exceeding the threshold for recognition took part in this cross-over clinical investigation, which consisted of a single use of four treatment arms with one week washout period in between. The treatments consisted of: (1) TC  +  BRx, (2) TC  +  water, (3) BRx and (4) water. Malodor levels and bacterial density were monitored up to 6 h by organoleptic scoring and selective plating, respectively. The organoleptic score and bacterial density were significantly lower after using TC  +  BRx compared to all alternative treatments at all time points. A significant decrease in both parameters was detected after a single use of TC  +  BRx, from levels characteristic of high oral malodor, to barely noticeable levels after treatment and this was maintained up to 6 h. Moreover, we identified a significant positive correlation between bacterial density and organoleptic score, confirming that bacterial tongue biofilm is the root cause of oral malodor in these subjects. The results of this clinical investigation demonstrated that the combined treatment of a sonic tongue brush with the antibacterial tongue spray is able to deliver more than 6 h of fresh breath following a single use. The clinical investigation was registered at the ISRCTN registry under study identification number ISRCTN38199132

An Attempt to Observe Debris from the Breakup of a Titan 3C-4 Transtage

In February 2007 dedicated observations were made of the orbital space predicted to contain debris from the breakup of the Titan 3C-4 transtage back on February 21, 1992. These observations were carried out on the Michigan Orbital DEbris Survey Telescope (MODEST) in Chile with its 1.3deg field of view. The search region or orbital space (inclination and right ascension of the ascending node (RAAN) was predicted using NASA#s LEGEND (LEO-to-GEO Environment Debris) code to generate a Titan debris cloud. Breakup fragments are created based on the NASA Standard Breakup Model (including fragment size, area-to-mass (A/M), and delta-V distributions). Once fragments are created, they are propagated forward in time with a subroutine GEOPROP. Perturbations included in GEOPROP are those due to solar/lunar gravity, radiation pressure, and major geopotential terms. Barker, et. al, (AMOS Conference Proceedings, 2006, pp. 596-604) used similar LEGEND predictions to correlate survey observations made by MODEST (February 2002) and found several possible night-to-night correlations in the limited survey dataset. One conc lusion of the survey search was to dedicate a MODEST run to observing a GEO region predicted to contain debris fragments and actual Titan debris objects (SSN 25000, 25001 and 30000). Such a dedicated run was undertaken with MODEST between February 17 and 23, 2007 (UT dates). MODEST#s limiting magnitude of 18.0 (S\N approx.10) corresponds to a size of 22cm assuming a diffuse Lambertian albedo of 0.2. However, based on observed break-up data, we expect most debris fragments to be smaller than 22cm which implies a need to increase the effective sensitivity of MODEST for smaller objects. MODEST#s limiting size can be lowered by increasing the exposure time (20 instead of 5 seconds) and applying special image processing. The special processing combines individual CCD images to detect faint objects that are invisible on a single CCD image. Sub-images are cropped from six consecutive CCD images with pixel shifts between images being consistent with the predicted movement of a Titan object. A median image of all the sub-images is then created leaving only those objects with the proper Titan motion. Limiting the median image in this manner brings the needed computer time to process all images taken on one night down to about 50 hours of CPU time

Turbulence compressibility corrections

The basic objective of this research was to identify, develop and recommend turbulence models which could be incorporated into CFD codes used in the design of the National AeroSpace Plane vehicles. To accomplish this goal, a combined effort consisting of experimental and theoretical phases was undertaken. The experimental phase consisted of a literature survey to collect and assess a database of well documented experimental flows, with emphasis on high speed or hypersonic flows, which could be used to validate turbulence models. Since it was anticipated that this database would be incomplete and would need supplementing, additional experiments in the NASA Ames 3.5-Foot Hypersonic Wind Tunnel (HWT) were also undertaken. The theoretical phase consisted of identifying promising turbulence models through applications to simple flows, and then investigating more promising models in applications to complex flows. The complex flows were selected from the database developed in the first phase of the study. For these flows it was anticipated that model performance would not be entirely satisfactory, so that model improvements or corrections would be required. The primary goals of the investigation were essentially achieved. A large database of flows was collected and assessed, a number of additional hypersonic experiments were conducted in the Ames HWT, and two turbulence models (kappa-epsilon and kappa-omega models with corrections) were determined which gave superior performance for most of the flows studied and are now recommended for NASP applications