Search NASA⌕ Search

SEARCH · Search NASA

Results for “STRIP”

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.

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

At least 1,045 records · Page 58
All sourcesNASA NTRSDOE OSTI
DOE OSTI2016

Microstructure evolution and mechanical properties of nano-SiCp/AZ91 composite processed by extrusion and equal channel angular pressing (ECAP)

Nano-SiCp/AZ91 magnesium matrix composite was fabricated by stir casting. The as-cast ingots were extruded at 350 °C, then processed by equal channel angular pressing (ECAP) at various temperatures (250 °C, 300 °C and 350 °C). Grains are significantly refined after the extrusion and the ECAP. A basal fibre texture was detected by neutron diffraction after the extrusion, which inclines about 45° to the extrusion direction (ED) after the ECAP. Nano-scaled SiC particles agglomerate in the as-cast composite. After the extrusion, the agglomeration tends to form continuous or discontinuous strips along the extrusion direction. By application of the ECAP, the agglomerated SiC particles are partly dispersed and the strips formed during the extrusion tend to be thinner and broken with the increasing pass number. The yield tensile strength (YTS) and the ultimate tensile strength (UTS) of the composite are dramatically increased after the extrusion. ECAP for one pass at various temperatures further increases the strength, however, the YTS decreases with the increasing ECAP temperature and the pass number. The Orowan equations predict the maximum YTS of the composite may be up to 400 MPa providing SiC particles are homogenously distributed in the matrix. - Highlights: •Nano-scaled SiC particles were successfully added into AZ91 by stirring casting. •Agglomeration of nano-particles were improved by extrusion and ECAP. •Yield strength of the composite is 328 MPa after one pass of ECAP. •Further ECAP process with optimized parameters may fully disperse nano-particles. •Yield strength is predicted to up to 400 MPa when particles are fully dispersed.

36 MATERIALS SCIENCE↗
DOE OSTI2018

Effect of niobium and phase transformation temperature on the microstructure and texture of a novel 0.40% C thermomechanically processed steel

Field emission scanning electron microscopy, electron backscatter diffraction (EBSD) and X-ray diffraction (XRD) have been employed to investigate the effect of niobium and phase transformation temperature on the evolution of microstructure and texture in a novel thermomechanically processed, medium‑carbon, low-alloy steel intended for slurry pipeline applications. Thermomechanical processing consisted of hot-rolling in the austenitic region with deformation both above the recrystallization limit temperature and below the recrystallization stop temperature. Immediately after rolling, specimens were directly quenched in water to two different temperatures of 560 °C and 420 °C and subsequently furnace cooled from those temperatures to simulate the cooling of coiled strip on a hot strip mill. The microstructure of samples quenched to 560 °C mostly comprised of upper bainite, whereas the samples quenched to 420 °C mainly consisted of lath-type lower bainite. The transformation texture of all samples at the mid-thickness position consisted of α, γ and ε-fibers with high intensities close to the transformed copper, transformed brass and rotated cube components. The addition of 0.013 wt% Nb refined the microstructure and sharpened the texture. The texture of the small fraction of retained austenite present in the final microstructures indicated that the main bcc texture components result from the brass and copper components in the parent austenite.

36 MATERIALS SCIENCE↗
DOE OSTI2018

The grain refinement mechanisms of various phases in shot-peened Nickel-Aluminum bronze (NAB) alloy

Highlights: • There exist two grain refinement mechanisms at the same time in the α phase. • The refinement of β' phase is attributed to the formation of dense and ordered nano twins. • The brittle strip-shape κ{sub iii} phases are fragmented after large deformation. • The κ{sub iv} and κ{sub ii} phases exhibit the twinning and dislocation deformation modes, separately. • The microhardness increases significantly owing to work hardening effect and grain refinement. - Abstract: In this study, coarse-grained Nickel-Aluminum bronze (NAB) alloy is subjected to shot-peening (SP) treatment, and the grain refinement mechanisms of various phases in shot-peened NAB alloy are investigated separately. The results show that severe deformation layers are produced on the surface. Meanwhile, refined grains with the average size below 100 nm are induced through SP treatment indicated by the results of X-ray diffraction (XRD) patterns. Various phases in NAB alloy including α, β' and three intermetallic phases (κ{sub ii}, κ{sub iii} and κ{sub iv}) display different grain refinement mechanisms. The grain refinement in the α phase involves dislocation segmentation in the precipitation-free zone and the twinning intersection in the precipitation zone. The formation of nanotwins by emitting partial dislocations at the grain boundary is found to be responsible for the grain refinement in the β' phase. As for the κ phases, the strip-shaped κ{sub iii} phases are fragmented after severe deformation, and the κ{sub iv} and κ{sub ii} phases exhibit the twinning and dislocation deformation modes, respectively. Also, the microhardness is significantly enhanced after SP treatment, which is mainly attributed to the work hardening effect and grain refinement.

36 MATERIALS SCIENCE↗
DOE OSTI2017

Studies with cathode drift chambers for the GlueX experiment at Jefferson Lab

A drift chamber system consisting of 24 1 m-diameter chambers with both cathode and wire readout (total of 12,672 channels) is operational in Hall D at Jefferson Lab (Virginia). Two cathode strip planes and one wire plane in each chamber register the same avalanche allowing the study of avalanche development, charge induction process, and strip resolution. We demonstrate a method for reconstructing the two-dimensional distribution of the avalanche “center-of-gravity” position around the wire from an 55 Fe source with resolutions down to 30 μm. We estimate the azimuthal extent of the avalanche around the wire as a function of the total charge for an Ar/CO 2 gas mixture. By means of cluster counting using a modified 3 cm-gap chamber, we observe significant space charge effects within the same track, resulting in an extent of the avalanche along the wire.

42 ENGINEERING↗
DOE OSTI2018

Construction and response of a highly granular scintillator-based electromagnetic calorimeter

Here, a highly granular electromagnetic calorimeter with scintillator strip readout is being developed for future linear collider experiments. A prototype of 21.5 X 0 depth and 180 × 180 mm 2 transverse dimensions was constructed, consisting of 2160 individually read out 10 × 45 × 3 mm 3 scintillator strips. This prototype was tested using electrons of 2–32 Ge V at the Fermilab Test Beam Facility in 2009. Deviations from linear energy response were less than 1.1%, and the intrinsic energy resolution was determined to be ( 12 . 5 ± 0 . 1 ( stat. ) ± 0 . 4 ( syst. ) ) % / E [ Ge V ] ⊕ ( 1 . 2 ± 0 . 1 ( stat. ) - 0 . 7 + 0 . 6 ( syst. ) ) % , where the uncertainties correspond to statistical and systematic sources, respectively.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2019

Charge collection in irradiated HV-CMOS detectors

Active silicon detectors built on p-type substrate are a promising technological solution for large area silicon trackers such as those at the High Luminosity LHC, but the radiation hardness of this novel approach has to be evaluated. Active n-in-p strip detector prototypes CHESS2 for ATLAS with different substrate resistivities in the range of 20-1000 Omega cm were irradiated with neutrons and protons up to a fluence of 2 x 10(15) n(eq) cm(-2) and 3.6 x 10(15) n(eq) cm(-2). Charge collection in passive test structures on the chip was evaluated using Edge-TCT and minimum ionising electrons from Sr-90. Results were used to assess radiation hardness of the detector in the given fluence range and to determine parameters of initial acceptor removal in different substrates.

active silicon detectors↗
DOE OSTI2018

Fabrication of low-cost, large-area prototype Si(Li) detectors for the GAPS experiment

A Si(Li) detector fabrication procedure has been developed with the aim of satisfying the unique requirements of the GAPS (General Antiparticle Spectrometer) experiment. Si(Li) detectors are particularly well-suited to the GAPS detection scheme, in which several planes of detectors act as the target to slow and capture an incoming antiparticle into an exotic atom, as well as the spectrometer and tracker to measure the resulting decay X-rays and annihilation products. These detectors must provide the absorption depth, energy resolution, tracking efficiency, and active area necessary for this technique, all within the significant temperature, power, and cost constraints of an Antarctic long-duration balloon flight. We report here on the fabrication and performance of prototype 2"-diameter, 1–1.25 mm-thick, single-strip Si(Li) detectors that provide the necessary X-ray energy resolution of ~4 keV for a cost per unit area that is far below that of previously-acquired commercial detectors. Lastly, this fabrication procedure is currently being optimized for the 4"-diameter, 2.5 mm-thick, multi-strip geometry that will be used for the GAPS flight detectors.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2018

A HV silicon vertical JFET: TCAD simulations

In the future ATLAS Inner Tracker detector (ITk), several silicon strip modules will be biased by a single High-Voltage (HV) line, so that a switch between each strip sensor and the HV line is required to disconnect faulty sensors. Such a switch must satisfy strict requirements, such as being radiation hard, being able to sustain high voltages in the OFF state and being able to operate in a high magnetic field. At Brookhaven National Laboratory we conceived a new kind of solid-state switch that can potentially meet all the specs: it is a HV silicon vertical JFET. Before designing and fabricating the JFET, we did a study using numerical TCAD simulations that demonstrate the feasibility of fabricating the device in a standard planar technology. As a result, we report such simulations, highlighting in particular a few key parameters to which the JFET performances are most sensitive.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2022

Investigation of signal characteristics and charge sharing in AC-LGADs with laser and test beam measurements

AC-LGADs, also referred to as resistive silicon detectors, are a recent development of low-gain avalanche detectors (LGADs), based on a sensor design where the multiplication layer and n + contact are continuous, and only the metal layer is patterned. In AC-LGADs, the signal is capacitively coupled from the continuous, resistive n + layer over a dielectric to the metal electrodes. Therefore, the spatial resolution is not only influenced by the electrode pitch, but also the relative size of the metal electrodes. Signal propagation between the metallized areas and charge sharing between electrodes plays a larger role in these detectors than in conventional silicon sensors read out in DC mode. AC-LGADs from two manufacturers were studied in beam tests and with infrared laser scans. The impact of n + layer resistivity and metal electrode pitch on the charge sharing and achievable position resolution is shown. For strips with 100 μm pitch, a resolution of ¡ 5 μm can be reached. Additionally, the charge sharing between neighboring strips is investigated in more detail, indicating the induction of signal charge and subsequent re-sharing over the n + layer. Furthermore, an approach to identify signal sharing over large distances is presented.

47 OTHER INSTRUMENTATION↗
DOE OSTI2025

Correcting beam space charge effects in Active-Target Time Projection Chamber

By providing a large gaseous volume for nuclear interactions while simultaneously recording the tracks of resulting reaction products, an active target serves as both a thick target and a detector. Once a reaction occurs, the emitted charged fragments strip electrons from the target gas along their path as they transverse the detector. Collection of these stripped electrons allow for detection of the product tracks. As beam intensity increases, the resulting ionization in the active target can significantly distort this collection of electrons. If left uncorrected, the resulting measurements could be wrong. In this paper, we investigate the impact of the space charge produced by heavy radioactive beams within the Active Target - Time Projection Chamber at Michigan State University. The beams are injected parallel to the electric field of the time projection chamber which is operated without a magnetic field for this experiment. Furthermore, we analyze the rate dependence of the space charge effects and demonstrate that they can be modeled and effectively corrected.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2018

The STAR BES-II and Forward Rapidity Physics and Upgrades

The second phase of the Beam Energy Scan at RHIC, BES-II, is scheduled to start in 2019 and will explore with precision measurements the high baryon density region of the QCD phase diagram. The detector upgrades will enhance some of the key measurements by extending STAR’s kinematical reach. Examples are the kurtosis of net-protons, which could pinpoint the position of a critical point. The upgrades currently under way comprise: the replacement of the inner TPC sectors, the Event Plane Detector and the end-cap TOF. Building on these upgrades STAR is planning to further enhance its detector capabilities by installing a Forward Calorimeter System integrating an electromagnetic and hadronic calorimeter and a Forward Tracking System combining 3 Silicon mini-strip disks and 4 Small-Strip Thin Gap Chamber (sTGC) wheels. The forward upgrade is motivated by studying the initial state of nucleons and nuclei and the exploration of cold QCD physics in the very high and low regions of x. This proceeding will highlight these upgrades and some of their selected physics opportunities.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2018

The crystal facet-dependent electrochemical performance of TiO 2 nanocrystals for heavy metal detection: Theoretical prediction and experimental proof

Tailored design/fabrication of electroanalytical materials with highly-active exposed crystal planes is of great importance for the development of electrochemical sensing. In this work, combining experimental and theoretical efforts, we reported a facile strategy to fabricate TiO 2 nanocrystals with tunable electrochemical performance for heavy metal detection. Density functional theory (DFT) calculations indicated that TiO 2 (001) facet showed relative larger adsorption energy and lower diffusion energy barrier toward heavy metal ions, which is favorable for obtaining better electrochemical stripping behaviors. Based on this prediction, a series of TiO 2 nanocrystals with different ratios of exposed (001) and (101) facets were synthesized. Electrochemical stripping experiments further demonstrated that with the increase of the percentage of exposed (001) facet, the sensitivity toward Pb(II) and Cd(II) was increased accordingly. When the percentage of exposed (001) facet was increased from 7% to 80%, the sensitivity increased by 190% and 93% for Pb(II) and Cd(II), respectively. In conclusion, our work provides an effective route to construct advanced electroanalytical materials for sensing.

47 OTHER INSTRUMENTATION↗
DOE OSTI2020

Comparative study on the overall energy performance between photovoltaic and Low-E insulated glass units

In this report a novel semi-transparent building integrated photovoltaic (BIPV) laminate was developed and introduced in this paper. It was produced by cutting standard mono-crystalline silicon solar cells into small strips and then making electrical connections between each strip before laminating the cells between two layers of glass. The overall energy performance and energy saving potential of the BIPV insulated glass unit (IGU) under real world conditions were identified through a side by side comparative study. Compared to the reference IGU, the BIPV IGU had lower solar heat gain coefficient (SHGC) but much higher U-factor. The average HVAC electricity saving of the BIPV IGU was about 10% relative to the reference IGU. Daylighting measurement and analysis were carried out to evaluate the trade-offs associated with the BIPV IGU between daylight, glare, and lighting energy use. The results indicated that the BIPV IGU is better than the reference IGU in reducing discomfort glare. However, if the most conservative viewpoint near the window is used for the assessment, a lower transmittance BIPV IGU is required to bring the overall discomfort levels below the perceptible level. Lastly, the net energy saving potential associated with the novel BIPV IGU was identified based on the power, thermal and daylighting performance. On average, the BIPV IGU saved 16.8% of the total electricity use of the room. Further studies and improvement on the energy conversion efficiency of solar cells, the optimal transmittance as well as the thermal properties would make this technology more energy-efficient and affordable.

14 SOLAR ENERGY↗
DOE OSTI2017

Lithium recycling and cathode material regeneration from acid leach liquor of spent lithium-ion battery via facile co-extraction and co-precipitation processes

Highlights: • A novel process for combining Li and cathode material recycling is developed. • Ni, Co and Mn are co-extracted and separated with Li. • Li recovered as Li{sub 2}CO{sub 3} with the purity of 99.2% is achieved. • The spherical cathode material LiNi{sub 1/3}Co{sub 1/3}Mn{sub 1/3}O{sub 2} is directly regenerated. - Abstract: A novel process for extracting transition metals, recovering lithium and regenerating cathode materials based on facile co-extraction and co-precipitation processes has been developed. 100% manganese, 99% cobalt and 85% nickel are co-extracted and separated from lithium by D2EHPA in kerosene. Then, Li is recovered from the raffinate as Li{sub 2}CO{sub 3} with the purity of 99.2% by precipitation method. Finally, organic load phase is stripped with 0.5 M H{sub 2}SO{sub 4}, and the cathode material LiNi{sub 1/3}Co{sub 1/3}Mn{sub 1/3}O{sub 2} is directly regenerated from stripping liquor without separating metal individually by co-precipitation method. The regenerative cathode material LiNi{sub 1/3}Co{sub 1/3}Mn{sub 1/3}O{sub 2} is miro spherical morphology without any impurities, which can meet with LiNi{sub 1/3}Co{sub 1/3}Mn{sub 1/3}O{sub 2} production standard of China and exhibits good electrochemical performance. Moreover, a waste battery management model is introduced to guarantee the material supply for spent battery recycling.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2017

Recovery of zinc and cadmium from spent batteries using Cyphos IL 102 via solvent extraction route and synthesis of Zn and Cd oxide nanoparticles

Highlights: • First time Cyphos IL102 explored for recovery of Zn/Cd from spent batteries. • Recovery of metals with high purity was achieved at room temperature. • Quantitative extraction was achieved in two stages for Zn and Cd. •Loaded organic phases were used to synthesize ZnO and CdO nanoparticles. •Simple strippants for stripping isotherm was used. - Abstract: The overall aim of this study is to separate and recover zinc and cadmium from spent batteries. For this purpose Cyphos IL 102 diluted in toluene was employed for the extraction and recovery of Zn and Cd from Zn-C and Ni-Cd batteries leach liquor. The influence of extractant concentration for the leach liquors of Zn-C (0.01–0.05 mol/L) and Ni-Cd (0.04–0.20 mol/L) batteries has been investigated. Composition of the leach liquor obtained from Zn-C/Ni-Cd spent batteries is Zn - 2.18 g/L, Mn - 4.59 g/L, Fe - 4.0 × 10{sup −3} g/L, Ni - 0.2 × 10{sup −3} g/L/Cd - 4.28 g/L, Ni - 0.896 × 10{sup −1} g/L, Fe - 0.148 g/L, Co - 3.77 × 10{sup −3} g/L, respectively. Two stage counter current extraction at A/O 1:1 and 3:2 with 0.04 mol/L and 0.2 mol/L Cyphos IL 102 for Zn and Cd, respectively provide more than 99.0% extraction of both the metal ions with almost negligible extraction of associated metal ions. A stripping efficiency of around 99.0% for Zn and Cd was obtained at O/A 1:1 using 1.0 mol/L HNO{sub 3} in two and three counter current stages, respectively. ZnO and CdO were also synthesized using the loaded organic phase and characterized using XRD, FE-SEM and EDX techniques. XRD peaks of ZnO and CdO correspond to zincite and monteponite, respectively. The average particle size was ∼27.0 nm and ∼37.0 nm for ZnO and CdO, respectively. The EDX analysis of ZnO and CdO shows almost 1:1 atomic percentage.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2018

Dual-Readout Immunochromatographic Assay by Utilizing MnO 2 Nanoflowers as the Unique Colorimetric/Chemiluminescent Probe

Manganese dioxide nanoflowers (MnO2 NFs) were synthesized and utilized as a dual readout probe to develop a novel immunochromatographic test strip (ITS) for detecting pesticide residues using chlorpyrifos as the model analyte. MnO2 NFs-labeled antibody for chlorpyrifos was employed as the signal tracer for conducting the ITS. After 10-min competitive immunoreaction, the tracer antibody was captured by the immobilized immunogen on test line in the test strip, resulting in the accumulation of MnO2 NFs. The accumulation of MnO2 NFs led to the appearance of brown color on the test line, which could be easily observed by the naked eye as a qualitative readout. Moreover, MnO2 NFs showed a remarkably enhancing effect on the luminol-H2O2 chemiluminescent (CL) system. Unlike peroxidase-like nanomaterials, the enhancing mechanism of MnO2 NFs was based on its oxidant activity to decompose H2O2 for forming reactive oxygen species. After initiating the CL system in the test zone, strong CL signal was collected as a quantitative readout to sensitively detect chlorpyrifos. Under optimal conditions, the linear range of chlorpyrifos was 0.1–50 ng/mL with a low detection limit of 0.033 ng/mL (S/N = 3). The reliability of the dual-readout ITS was successfully demonstrated by the application on traditional Chinese medicine and environmental water samples. Due to the simultaneous rapid-qualitative and sensitive-quantitative detection, the dual-readout protocol provides a promising strategy for rapid screening and field assay on various areas such as environmental monitoring, food safety and point-of-care testing.

Ouyang, Hui↗
DOE OSTI2025

Bio-Oil Impact on Water Diffusion and Durability of Bitumen: Influence of Aging and Salinity

Bio-oils derived from inexpensive biomass offer environmentally friendly options for modifying bitumen for improved durability or rejuvenating aged material, although their impact on bitumen moisture resistance can be mixed. A better understanding of water diffusion into bitumen and its interactions with bio-oil compounds would aid the development of effective bio-oils. In this study, the effect of water exposure on bio-oil-modified bitumen blends was examined by de-wetting contact angle measurements and differential FTIR spectroscopy. The bio-oils improved the anti-stripping behavior of the bitumen but also increased water absorption which could weaken cohesive strength. Short-term thermal aging increased water diffusion for all bitumen blends including the control, probably due to the presence of more oxidized compounds. Negative peaks of alkanes and polar groups in the differential FTIR data suggest the co-diffusion of surfactant molecules towards the bitumen-water interface. Basic pH increased de-wetting of some bitumen blends from silica, possibly by attacking the silica surface itself. The presence of salt in solution altered the bitumen surface composition through the formation of salt complexes with bitumen or bio-oil compounds. In particular, the formation of calcium-carboxylate complexes appeared to greatly improve anti-stripping effects of bio-oils. Water diffusion into most of the bitumen blends was insensitive to pH or salt concentration except for a few notable outliers. Identifying the compounds responsible for increasing or decreasing water diffusion in these outlier cases would be valuable developing future bio-oil formations that avoid or promote those compounds.

Hung, Albert M.↗
DOE OSTI2023

Rapid Quantification of 237 U Specific Activity for Nuclear Forensics

In the event of an unattributed nuclear explosion, rapid assessment of the short-lived uranium isotope activity and mass can provide valuable information for subsequent forensic analysis. Rapid analysis in the field is enabled by using microfluidic chemistry and deployable instrumentation. Here, this work presents a flow chemistry system, controlled in LabVIEW, that integrates three functionalities: (1) selective extraction of uranium from the sample matrix via a 3D-printed supported liquid membrane module; (2) UV–visible absorbance spectrophotometry to measure the total uranium concentration in the strip flow; and (3) a portable CdTe γ-ray spectrometer coupled to a 3D-printed flow cell to measure 237 U activity concentration in the strip solution. The system was calibrated using standard solutions, and its functionality was demonstrated using a solution of depleted uranium spiked with 237 U. Uranium concentrations of 40–5000 μg/mL were directly quantified online using a 100 mm optical flow cell, while concentrations of 0.5–10 μg/mL were quantified online using a colorimetric reagent. The mass concentration measurement takes approximately 60 min while the activity concentration via γ-ray spectrometry varies depending on the activity of 237 U, with 1 kBq/mL requiring about 30 min of acquisition time to obtain <10% uncertainty at 1σ. This platform provides a fieldable approach for quantifying uranium mass and radioactivity relevant to postdetonation nuclear debris.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗