SEARCH · Engineering Papers

Results for “SCREENING”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 235 records · Page 13

All sources NASA NTRS DOE OSTI

DOE OSTI2025

Optimization of X-ray event screening using ground and in-orbit data for the Resolve instrument onboard the XRISM satellite

The X-Ray Imaging and Spectroscopy Mission (XRISM) satellite was successfully launched and put into a low-Earth orbit on September 6, 2023 (UT). The Resolve instrument onboard XRISM hosts an X-ray microcalorimeter detector, which was designed to achieve a high-resolution ( ≤ 7 eV FWHM at 6 keV), high-throughput, and non-dispersive spectroscopy over a wide energy range. It also excels in a low background with a requirement of < 2 × 10 -3 s -1 keV -1 (0.3 to 12.0 keV), which is equivalent to only one background event per spectral bin per 100-ks exposure. Event screening to discriminate X-ray events from background is a key to meeting the requirement. We present the result of the Resolve event screening using data sets recorded on the ground and in orbit based on the heritage of the preceding X-ray microcalorimeter missions, in particular, the Soft X-ray Spectrometer onboard ASTRO-H. We optimize and evaluate 19 screening items of three types based on (1) the event pulse shape, (2) relative arrival times among multiple events, and (3) good time intervals. We show that the initial screening, which is applied for science data products in the performance verification phase, reduces the background rate to 1.8 × 10 -3 s -1 keV -1 meeting the requirement. We further evaluate the additional screening utilizing the correlation among some pulse shape properties of X-ray events and show that it further reduces the background rate, particularly in the < 2 keV band. Over 0.3 to 12 keV, the background rate becomes 1.0 × 10 -3 s -1 keV -1 .

47 OTHER INSTRUMENTATION↗

DOE OSTI2014

Composition Driven, Statistical Review of Cast Stone Screening Matrix Results

Recent studies in support of Cast Stone development for the Hanford Site were designed to screen the effects of mix components on properties and performance of the waste form. Dry blend components, including portland cement, blast furnace slag, and Class F fly ash, sourced from both southeastern and northwestern suppliers, were included in the screening matrix. Multiple decontaminated salt solutions (simulated) were combined with the dry blend components at various liquid to solid ratios following a statistically designed matrix of compositions. Properties of the resulting mixes and performance of the cured materials were then measured and related to the dry blend components and salt solutions that were used for each mix. At the conclusion of the screening matrix work, SRNL felt that additional insight into the study might be obtained by relating the properties and performance of the materials to the composition of each Cast Stone mix, as opposed to just the dry blend – salt solution combination. This memorandum provides the results of a statistically driven review of the screening matrix data as a function of the composition of each mix. It is meant to augment the results obtained by reviewing the screening matrix data as a function of the dry blend and salt solution combination.

Edwards, T. B.↗

DOE OSTI2019

Seismic Moment Tensor Screening on the Hypersphere: Application to an Earthquake Population

A population of earthquakes is considered in the moment tensor screening frame- work. First, the members of the population are tested using the spherical distance statistic discussed in Ford and Kraft. All members are screened out, which is to say the explosion hypothesis is rejected at high confidence.Then, to gain insight to non-explosion populations, we estimate the distribution parameters for the earthquake population. Descriptive parameters of the population suggest it is ill-suited for description by a unimodal distribution on the hypersphere such as the von Mises Fisher distribution that described the explosion population. Nevertheless, we define an earthquake screening statistic based on the best-fit distribution parameters. No explosions are screened out, which is to say the earthquake hypothesis is not rejected for these events resulting in a poor screening performance.

58 GEOSCIENCES↗

DOE OSTI2021

CO 2 Storage Site Screening Platform Development and CO 2 Storage Resource Analysis in SECARB Offshore Reservoirs Using SAS Viya

A major goal of the SECARB Offshore Partnership (DE-FE0031557) is to screen deep saline aquifers and hydrocarbon reservoirs in the central Gulf of Mexico for CO 2 sequestration and CO 2 -enhanced oil and gas recovery (EOR/EGR) and estimate the corresponding CO 2 storage resources for select reservoirs. CO 2 storage potential associated with offshore CO 2 -EOR is considerable and likely represents “low hanging fruit” for near-term CO 2 storage given the in-place infrastructure in the region. It is for these reasons that this assessment focuses on oil and gas fields. To this end, three major objectives have been completed and include (1) managing geological data derived from different sources, (2) building a reservoir screening platform for CO 2 storage, and (3) ranking the reservoirs based on the estimated CO 2 storage resources. The SAS ® Viya platform was used for data management and analytics. The Viya platform is a cloud service platform that provides data integration, data management, quick analytics, data visualization, machine learning functions, and application programming interfaces (APIs) for multi-programming languages. Different sources of data containing geologic information, reservoir properties, and EOR/EGR information were collected, cleaned, formatted, and loaded into the SAS ® Viya platform for evaluation. The major geological characteristics of both shelf and deep-water areas of the central Gulf were examined and compared to define the appropriate reservoir screening criteria. Next, a CO 2 storage site screening system was built in the SAS ® Viya platform with the pre-defined criteria. Finally, the CO 2 storage resources of the screened reservoirs were calculated and reported at the BOEM field level to identify fields with the highest estimated CO 2 storage resource. The fields with the largest total estimated CO 2 storage resource are located in the Mississippi Canyon protraction area. Due to proximity to the Mississippi Delta (indicative of less infrastructure) and large estimated CO 2 storage resources, future development activities may wish to focus efforts in the Mississippi Canyon protraction area.

02 PETROLEUM↗

DOE OSTI2022

Making a Deal with the Devilfish: Biometric-Informed Screening Technology CRADA - 514 (Final Report)

This report documents an investigation into the performance of a novel fish-protection screen intended to prevent small aquatic and marine organisms from entering water intakes in free-flowing water bodies. The proposed prototype screen resembles conventional, slotted fish-protection screens with parallel wires or bars; however, the prototype bars are shaped to mimic the filter elements in the mouths of filter-feeding fishes such as the devil ray (Mobula tarapacana). Millions of years of evolution have perfected these structures to provide energetically efficient and clog-resistant filtering of zooplankton from seawater. The intent of the prototype is to exploit these mechanisms for the protection of similarly sized, or larger, organisms in settings where the freely flowing current is approximately parallel with the screen face (i.e., sweeping flow) and perpendicular to the screen bars.

42 ENGINEERING↗

NASA NTRS1974

Wicking of liquids in screens

An investigation was conducted to determine the magnitude of the wicking rates of liquids in various screens. Evaluation of the parameters characterizing the wicking process resulted in the development of an expression which defined the wicking velocity in terms of screen and system geometry, liquid properties, and gravitational effects. Experiment data obtained both in normal gravity and in weightlessness demonstrated that the model successfully predicted the functional relation of the liquid properties and the distance from the liquid source to the wicking velocity. Because the pore geometry in the screens was complex, several screen geometric parameters were lumped into a single constant which was determined experimentally for each screen.

Symons, E. P.↗

NASA NTRS1976

Study of liquid jet impingement on screens

A model is presented for an unconfined flow, such as a free jet, impinging on a screen which incorporates the influence of liquid deflection by the screen. The boundary layer blockage coefficient is introduced. This coefficient depends on the screen weave geometry and the jet impingement angle, and essentially accounts for the increase in fluid particle trajectory length through the screen resulting from the flow deflection. Comparisons were made with previous experimental studies to determine empirical values of the blockage coefficient. It is concluded that the new model reliably predicts the bulk flow and penetration characteristics of an impinging liquid jet interacting with a screen.

Dodge, F. T.↗

NASA NTRS1978

Effect of vibration on retention characteristics of screen acquisition systems

The design of surface tension propellant acquisition systems using fine-mesh screen must take into account all factors that influence the liquid pressure differentials within the system. One of those factors is spacecraft vibration. Analytical models to predict the effects of vibration have been developed. A test program to verify the analytical models and to allow a comparative evaluation of the parameters influencing the response to vibration was performed. Screen specimens were tested under conditions simulating the operation of an acquisition system, considering the effects of such parameters as screen orientation and configuration, screen support method, screen mesh, liquid flow and liquid properties. An analytical model, based on empirical coefficients, was most successful in predicting the effects of vibration.

Tegart, J. R.↗

NASA NTRS1985

Flow through very porous inclined screens

The steady, inviscid flow through and around a screen inclined at a uniform angle to the incoming flow was investigated. For a screen placed in an infinite flow field, an asymptotic analysis for small resistance coefficients was performed, and the effects of inclination were determined. The velocity at first order in the asymptotic expansion was nonuniform along the screen. This nonuniformity caused the wake behind the screen to contain distributed vorticity at second order. These effects therefore occurred at one order lower than for normal screens.

Muramoto, K. K.↗

NASA NTRS1985

Electrostatic shielding of a charged conducting sphere by a fine-mesh grounded screen

A simple model of an electrostatic-shielding arrangement that will reduce the electric field from the Near Infrared Mapper Spectrometer aboard the Galileo spacecraft is presented. The system considered consists of a charged conducting sphere held at a fixed absolute potential via a power source. This system is screened by a larger, concentric sphere made of fine mesh which is grounded. A derivation based on elementary principles of electrostatics is used to show that the shielding effectiveness of the screen can be expressed in terms of the separation between the two spheres and another quantity B that is an intrinsic property of the screen. For a given screen, B can be determined by measuring the capacitance per unit area and separation between a flat piece of the screen and a parallel metal plate.

Edmonds, L.↗

NASA NTRS1985

Flow through very porous inclined screens

Muramoto, K. K.↗

NASA NTRS1989

Large screen display for the Mission Control Center

The Mission Control Center (MCC), located at the Johnson Space Center near Houston, Texas, is the primary point of control and monitoring for National Space Transportation System (NSTS) flight activities. NSTS flight managers monitor and command spacecraft from one of two Flight Control Rooms (FCR). Each FCR is equipped with five large screen displays for group dissemination of spacecraft system status and vehicle position relative to Earth geography. The primary or center screen display is ten feet in height and twenty feet in width. The secondary or side screens are seven and one-hald feet high and ten feet wide. The center screen projection system is exhibiting high maintenance costs and is considered to be in wear-out phase. The replacement of the large center screen displays at the MCC is complicated by the unique requirements of the Flight Controller user. These requirements demand a very high performance, multiple color projection system capable of the display of high resolution text, graphics and images produced in near real time. The current system to be replaced, the replacement system requirements, the efforts necessary to procure the major element of this system (the projector) for the government, and how the new capabilities are to be integrated into the existing MCC operational configuration are discussed.

Skudlarek, Martin J.↗

NASA NTRS1991

Vapor-Screen-Density Controller

Density of vapor screen in wind tunnel maintained for vapor-screen photography. Vapor-screen density controller developed to control reflectivity by closed-loop means. Eliminates large step-response corrections and possesses more than enough frequency response to maintain nearly constant density in vapor screen in undisturbed flow ahead of model. Device enables user to control density of vapor screen via set-point indicator. User given indication of percentage transmittance across test section.

Byrd, James E.↗

NASA NTRS1993

SLR data screening; location of peak of data distribution

At the 5th Laser Ranging Instrumentation Workshop held at Herstmonceux in 1984, consideration was given to the formation of on-site normal points by laser stations, and an algorithm was formulated. The algorithm included a recommendation that an iterated 3.0 x rms rejection criterion should be used to screen the data, and that arithmetic means should be formed within the normal point bins of the retained data. From Sept. 1990 onwards, this algorithm and screening criterion have been brought into effect by various laser stations for forming on-site normal points, and small variants of the algorithm are used by most analysis centers for forming normal points from full-rate data, although the data screening criterion they use ranges from about 2.5 to 3.0 x rms. At the CSTG Satellite Laser Ranging (SLR) Subcommission, a working group was set up in Mar. 1991 to review the recommended screening procedure. This paper has been influenced by the discussions of this working group, although the views expressed are primarily those of this author. The main thrust of this paper is that, particularly for single photon systems, a more important issue than data screening is the determination of the peak of a data distribution and hence, the determination of the bias of the peak from the mean. Several methods of determining the peak are discussed.

Sinclair, Andrew T.↗

NASA NTRS1995

Automated Propulsion Data Screening demonstration system

A fully-instrumented firing of a propulsion system typically generates a very large quantity of data. In the case of the Space Shuttle Main Engine (SSME), data analysis from ground tests and flights is currently a labor-intensive process. Human experts spend a great deal of time examining the large volume of sensor data generated by each engine firing. These experts look for any anomalies in the data which might indicate engine conditions warranting further investigation. The contract effort was to develop a 'first-cut' screening system for application to SSME engine firings that would identify the relatively small volume of data which is unusual or anomalous in some way. With such a system, limited and expensive human resources could focus on this small volume of unusual data for thorough analysis. The overall project objective was to develop a fully operational Automated Propulsion Data Screening (APDS) system with the capability of detecting significant trends and anomalies in transient and steady-state data. However, the effort limited screening of transient data to ground test data for throttle-down cases typical of the 3-g acceleration, and for engine throttling required to reach the maximum dynamic pressure limits imposed on the Space Shuttle. This APDS is based on neural networks designed to detect anomalies in propulsion system data that are not part of the data used for neural network training. The delivered system allows engineers to build their own screening sets for application to completed or planned firings of the SSME. ERC developers also built some generic screening sets that NASA engineers could apply immediately to their data analysis efforts.

Hoyt, W. Andes↗

NASA NTRS1959

Experimental Investigation of Expanded Duct Sections and Screens for Reducing FLow Distortions at Subsonic Flows

An investigation of expanded duct sections and the effect of their design parameters on flow distortion over a duct Mach number range of 0.19 to 0.67 was conducted in the small tunnel facility of the Lewis Research Center. The parameters investigated were: (1) entrance angle of expanded section, (2) length of expanded section, (3) area ratio of expanded section, (4) location of expanded section relative to the engine face, and (5) the use of screens of varying solidities and mesh. Expansion half-angles of deg, 15 deg, and 30 deg reduced the total-pressure distortions induced in the duct. The larger expansion angles reduced circumferential distortion more effectively than radial distortion. However, the half-angle of 15 deg appeared to be optimum for reducing both radial and circumferential distortions while still maintaining a high total-pressure recovery. Increasing the expanded-section area ratio and increasing the expanded-section lengths with-the 150 expansion half-angle led to less total-pressure distortion with no appreciable loss in pressure recovery. Screens incorporated in the expanded section indicated that 22.2-percent- solidity screens decreased distortion still further.while 37.3-percent- solidity screens generally increased distortion above that of a constant- area duct incorporating the same solidity screen.

Chiccine, Bruce G.↗

NASA NTRS2005

Screen Channel Liquid Acquisition Devices for Cryogenic Propellants

This paper describes an on-going project to study the application screen channel liquid acquisition devices to cryogenic propellant systems. The literature of screen liquid acquisition devices is reviewed for prior cryogenic experience. Test programs and apparatus are presented to study these devices. Preliminary results are shown demonstrating bubble points for 200 x 1400 wires per inch and 325 x 2300 wires per inch Dutch twill screens. The 200 x 1400 screen has a bubble point of 15.8 inches of water in isopropyl alcohol and 6.6 inches of water in liquid nitrogen. The 325 x 2300 screen has a bubble point of 24.5 inches of water in isopropyl alcohol, 10.7 inches of water in liquid nitrogen, and 1.83 inches of water in liquid hydrogen. These values are found to be in good agreement with the results reported in the literature.

Chato, David J.↗

NASA NTRS1980

Low conducting metal screen support flange

In a very high or very low temperature duct system in which duct insulation is terminated at selected locations so as to be not coextensive with the duct, an annular metal perforated or mesh screen support flange is used, as a low conductor of heat or cold, between the duct and an outer insulation cover to retain the end of the insulation and to support its usually very thin cover. The screen may be Z-shaped in cross section having a small diameter annular portion to surround and be secured to the duct adjacent the end of the insulation. A generally radially extending portion of the screen extends outwardly from the small diameter portion and adjacent the end of the insulation. The periphery of the radially extending portion is in alignment with the outer peripheral surface of the insulation and the outer peripheral surface of the insulation cover. A large diameter annular portion of the screen extends longitudinally from the periphery in the direction opposite the small diameter portion, and is adapted to surround the insulation and its cover and be secured thereto. The screen may also be U or channel-shaped with one longitudinally directed leg secured to the insulation cover and the other leg secured to the duct under the insulation.

Lestak, Robert G.↗