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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.

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At least 1,279 records · Page 71

All sources NASA NTRS DOE OSTI

DOE OSTI2015

Microwave heating of aqueous samples on a micro-optical-electro-mechanical system

Apparatus for heating a sample includes a microchip; a microchannel flow channel in the microchip, the microchannel flow channel containing the sample; a microwave source that directs microwaves onto the sample for heating the sample; a wall section of the microchannel flow channel that receives the microwaves and enables the microwaves to pass through wall section of the microchannel flow channel, the wall section the microchannel flow channel being made of a material that is not appreciably heated by the microwaves; a carrier fluid within the microchannel flow channel for moving the sample in the microchannel flow channel, the carrier fluid being made of a material that is not appreciably heated by the microwaves; wherein the microwaves pass through wall section of the microchannel flow channel and heat the sample.

42 ENGINEERING↗

DOE OSTI2016

Direct impact aerosol sampling by electrostatic precipitation

The present disclosure provides apparatuses for collecting aerosol samples by ionizing an air sample at different degrees. An air flow is generated through a cavity in which at least one corona wire is disposed and electrically charged to form a corona therearound. At least one grounded sample collection plate is provided downstream of the at least one corona wire so that aerosol ions generated within the corona are deposited on the at least one grounded sample collection plate. A plurality of aerosol samples ionized to different degrees can be generated. The at least one corona wire may be perpendicular to the direction of the flow, or may be parallel to the direction of the flow. The apparatus can include a serial connection of a plurality of stages such that each stage is capable of generating at least one aerosol sample, and the air flow passes through the plurality of stages serially.

47 OTHER INSTRUMENTATION↗

DOE OSTI2016

Microwave heating of aqueous samples on a micro-optical-electro-mechanical system

36 MATERIALS SCIENCE↗

DOE OSTI2016

System and method for liquid extraction electrospray-assisted sample transfer to solution for chemical analysis

A system for sampling a surface includes a surface sampling probe comprising a solvent liquid supply conduit and a distal end, and a sample collector for suspending a sample collection liquid adjacent to the distal end of the probe. A first electrode provides a first voltage to solvent liquid at the distal end of the probe. The first voltage produces a field sufficient to generate electrospray plume at the distal end of the probe. A second electrode provides a second voltage and is positioned to produce a plume-directing field sufficient to direct the electrospray droplets and ions to the suspended sample collection liquid. The second voltage is less than the first voltage in absolute value. A voltage supply system supplies the voltages to the first electrode and the second electrode. The first electrode can apply the first voltage directly to the solvent liquid. A method for sampling for a surface is also disclosed.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

DOE OSTI2015

Sampling Tools for Contaminated Hot Cells and Remotely Accessed Tanks

The U.S. Department of Energy (DOE) and the Pacific Northwest National Laboratory in collaboration with the Andronikashvili Institute of Physics in Tbilisi, Georgia have developed and tested technologies which sample contaminated areas inside hot cell facilities. Sampling locations in the facility include drains, ventilation exhaust ducts, sumps and shielded waste tanks. Tool designs for sampling each location include the ability to introduce the tool using existing ports, pass-throughs or inter-cells trolley and operate the tool with the existing remote manipulators. Areas inside the hot cell facility that would likely be contaminated from chemically processing irradiated reactor targets and fuel even after decontamination have been identified as potential sampling locations. Andronikashvili Institute of Physics in Tbilisi, Georgia has access to a reactor, hot cells, glove boxes and storage facilities that have been used to develop and test hot cell sampling technologies. These facilities are uncontaminated with radiological material and provide the ability to test these sampling technologies on representative equipment without contaminating the tools. Prototype tools have been fabricate and tested at these facilities using simulants representative of radiological contamination and waste.

Rostomashvili, Z.↗

DOE OSTI2017

Synchronizing data from irregularly sampled sensors

A system and method include receiving a set of sampled measurements for each of multiple sensors, wherein the sampled measurements are at irregular intervals or different rates, re-sampling the sampled measurements of each of the multiple sensors at a higher rate than one of the sensor's set of sampled measurements, and synchronizing the sampled measurements of each of the multiple sensors.

47 OTHER INSTRUMENTATION↗

DOE OSTI2020

Hollow fiber mid-ID spectrometer with UV laser ablation sampling for fine spatial reoslution of isotope ratios in solids

We describe a system that combines isotope ratio analysis via mid-infrared (Mid-IR) laser absorption spectroscopy with fine spatial resolution sampling using a UV pulsed laser. The UV laser ablates a pit in a solid on the order of 10 microns in diameter. The sample-derived particulates resulting from laser ablation pass through a micro-combustor, and the resulting gas is analyzed using Mid-IR laser absorption spectroscopy in a capillary absorption spectrometer (CAS). The CAS uses a hollow fiber optic waveguide with a reflective inner coating and a small internal volume on the order of 1ml. The hollow fiber both guides the laser light from source to detector and contains the gas sample at reduced pressure. Near unity overlap between the laser beam and sample enables sensitive analysis with ultra-small sample size. A prototype system has been demonstrated to enable stable carbon isotopic analysis (d13C) with 1 per mil precision using <1 picomole of carbon and is currently being used to study nutrient exchange in soil/root/microbial rhizosphere studies. The smaller sample size of this system is enabling fine spatial resolution analysis (on the order of 10 microns), which is roughly an order of magnitude smaller than was possible with an isotope ratio mass spectrometer (IRMS). In addition to rhizosphere studies, the system can provide a useful tool for fine scale isotope analysis with applications in biological, forensic, and environmental science.

capillary absorption spectroscopy, laser ablation,↗

DOE OSTI2021

High efficiency environmental sampling with rapidly cured peelable coatings

A rapidly curable liquid gel for collecting an analyte from a sampling surface includes a polymer precursor mixture including a monomer and/or an oligomer; and an additive to enhance extraction of the analyte from the sampling surface. A kit for collecting an analyte from a sampling surface may include the rapidly curable liquid gel and a portable device for rapidly curing the gel. The rapidly curable liquid gel is cured to thereby form a peelable sampling film, and the sampling film is removed from the sampling surface, thereby collecting the analyte. In one embodiment, the rapidly curable liquid gel is UV-curable, the polymer precursor mixture further includes a photoinitiator compound, and the portable device includes a UV light source configured to emit UV light of a wavelength range absorbed by the photoinitiator compound.

Henzl, Vladimir↗

DOE OSTI2020

C-SAW: a framework for graph sampling and random walk on GPUs

Many applications require to learn, mine, analyze and visualize large-scale graphs. These graphs are often too large to be addressed efficiently using conventional graph processing technologies. Fortunately, recent research efforts find out graph sampling and random walk, which significantly reduce the size of original graphs, can benefit the tasks of learning, mining, analyzing and visualizing large graphs by capturing the desirable graph properties. This paper introduces C-SAW, the first framework that accelerates Sampling and Random Walk framework on GPUs. Particularly, C-SAW makes three contributions: First, our framework provides a generic API which allows users to implement a wide range of sampling and random walk algorithms with ease. Second, offloading this framework on GPU, we introduce warp-centric parallel selection, and two novel optimizations for collision migration. Third, towards supporting graphs that exceed the GPU memory capacity, we introduce efficient data transfer optimizations for out-of-memory and multi-GPU sampling, such as workload-aware scheduling and batched multi-instance sampling. Taken together, our framework constantly outperforms the state of the art projects in addition to the capability of supporting a wide range of sampling and random walk algorithms.

97 MATHEMATICS AND COMPUTING↗

DOE OSTI2016

Nuclear fuel behavior at high temperature: new insights from post-test examinations on the VERDON-1 sample

In order to reduce the uncertainties concerning Source Term assessment under Light Water Reactor (LWR) severe accident conditions, 4 VERDON tests were recently performed. They have been defined in the framework of the International Source Term Program and carried out at CEA Cadarache, in the LECA-STAR facility. Among these 4 VERDON tests, VERDON-1 test was devoted to high burn-up UO{sub 2} fuel behavior and FP release under H{sub 2} reducing conditions at very high temperature. This test was performed with the Release Circuit, which is devoted to the precise characterization of the FP release, in terms of FP release kinetics and fission products (FPs) released fraction. The main components of the circuits are a furnace heating the fuel sample, a filter trapping the emitted aerosols and gamma spectrometry detectors for online and post-test measurements. VERDON-1 test was conducted up to about 2600 Celsius degrees without reaching global fuel relocation, allowing thereby post-test micro-analyses. After a brief description of the fuel sample nature and the experimental set-up, we present the progress of the experimental sequence and the associated gamma spectrometry measurements. We then focus on the major results of the VERDON-1 tests regarding the fuel global behavior. These results are obtained by two complementary techniques. First, the fuel sight gamma station can be used either on-line to detect fuel relocation or just after the test, as a longitudinal bench, to get preliminary information on the global shape of the fuel sample inside the furnace. Secondly, these information are completed by post-test examinations performed on the fuel sample after extraction from the furnace. Complete qualitative and quantitative characterizations, including EPMA (Electron Probe Micro-Analysis) and SEM (Scanning Electron Microscopy) analysis, were performed for the first time at the CEA Cadarache on a sample that has been submitted to such severe accident conditions. These results show an advanced state of sample degradation, with locally previously molten areas, meaning that fuel global relocation was imminent by the end of thermal-hydraulic sequence. The relocation temperature is compared to that of previous VERCORS tests and discussed regarding the atmosphere of the test and possible UO{sub 2}-ZrO{sub 2} interaction. (authors)

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

DOE OSTI2024

Humidified sample preparation station for serial crystallography

Humidified sample preparation station for serial crystallography according to one embodiment is a humidified enclosure that delivers relative humidities above 95% and preferably above 97% in standard operation, and that can allow microscope observation of samples within. Humidified sample preparation station for serial crystallography can be used for preparation of protein crystal samples for examination using X-rays and for protein structure determination by X-ray crystallography, involving addition of liquid to the sample and removal of liquid from the sample using vacuum or suction.

Jayne, Richard↗

DOE OSTI2024

High efficiency active environmental sampling of chemical traces

A method of sample collection includes collecting an analyte from a sampling surface using a rapidly curable liquid gel comprising one or more metal particles; co-aggregating the one or more metal particles from the rapidly curable liquid gel and the analyte from the sampling surface; and rapidly curing the rapidly curable liquid gel. The composition and sample preparation conditions may facilitate improved collection efficiency of analytes during environmental and forensic evidence sampling. In addition, the composition and sample preparation conditions may facilitate enhanced detection and identification of the analyte using e.g., Surface Enhanced Raman Spectrometry (SERS).

Junghans, Ann↗

DOE OSTI2024

Apparatus and methods for sample analysis with multi-gradient microfluidics

A device for analyzing biological samples comprises first, second, third, and fourth layers. The first layer comprises a sample chamber in which a sample is positioned. The second layer comprises first, second, and third channels. A third, porous layer is positioned between the first layer and the second layer. A fourth layer composed of a substantially liquid-impermeable material is positioned between the second layer and the third layer. The fourth layer includes first and second pass-through channels that are aligned with the first and second channel, respectively. Fluids that flow in the first and second channels pass through the pass-through channels and diffuse into the sample chamber, establishing a chemical concentration gradient therein. A gas in the sample chamber can diffuse through the third and fourth layers and interact with a fluid flowing in the third channel, establishing a gas concentration gradient in the sample chamber.

Kim, Peter Wonhee↗

DOE OSTI2025

Analysis Of Fracture Location on Tensile Graphite Samples

The main standard for testing the ultimate tensile strength of graphite is ASTM C749. Commercial entities have raised concerns about samples breaking outside of the gauge section, particularly in the radius or head of the sample. When this occurs, the data gathered from the samples is unusable and increases the cost of testing as more samples will need to be machined. This study investigates the locations and frequency of sample breakage for four different grades of graphite using a custom-made measurement scale. The four grades include two fine-grain (2114 and IG-110) and two medium/coarse-grain (NBG-17 and PCEA). Our results show that fine-grain grades are more susceptible to breaking outside the gauge section, with almost 30% of the samples from grade 2114 breaking outside this region. Additionally, the radius being too small causes stress concentrations near the ends of the gauge section resulting in a bimodal distribution of the fracture locations.

36 - MATERIALS SCIENCE↗

DOE OSTI2023

An interoperable implementation of collective‐variable based enhanced sampling methods in extended phase space within the OpenMM package

Collective variable (CV)-based enhanced sampling techniques are widely used today for accelerating barrier-crossing events in molecular simulations. A class of these methods, which includes temperature accelerated molecular dynamics (TAMD)/driven-adiabatic free energy dynamics (d-AFED), unified free energy dynamics (UFED), and temperature accelerated sliced sampling (TASS), uses an extended variable formalism to achieve quick exploration of conformational space. These techniques are powerful, as they enhance the sampling of a large number of CVs simultaneously compared to other techniques. Extended variables are kept at a much higher temperature than the physical temperature by ensuring adiabatic separation between the extended and physical subsystems and employing rigorous thermostatting. Here, in this work, we present a computational platform to perform extended phase space enhanced sampling simulations using the open-source molecular dynamics engine OpenMM. The implementation allows users to have interoperability of sampling techniques, as well as employ state-of-the-art thermostats and multiple time-stepping. This work also presents protocols for determining the critical parameters and procedures for reconstructing high-dimensional free energy surfaces. As a demonstration, we present simulation results on the high dimensional conformational landscapes of the alanine tripeptide in vacuo, tetra-N-methylglycine (tetra-sarcosine) peptoid in implicit solvent, and the Trp-cage mini protein in explicit water.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

DOE OSTI2023

High-throughput mass spectrometry analysis using immediate drop-on-demand technology coupled with an open port sampling interface

Rationale: The sampling throughput of immediate drop-on-demand technology (I.DOT) coupled with an open port sampling interface (OPSI) is limited by software communication. To enable much-needed high-throughput mass spectrometry (MS) analysis capabilities, a novel software was developed that allows for flexible sample selection from a 96-well plate and for maximized analysis throughput using I.DOT/OPSI-MS coupling. Methods: Wells of a 96-well I.DOT plate were filled with propranolol solution and were used to test maximum sampling throughput strategies to minimize analysis time. Demonstration of chemical reaction monitoring was done using acid-catalyzed ring closure of 2,3-diaminonaphthalene (DAN) with nitrite to form 2,3-naphthotriazole (NAT). Analytes were detected in positive electrospray ionization mode using selected reaction monitoring. Results: A maximum throughput of 1.54 s/sample (7.41 min/96-well plate with three technical replicates) was achieved, and it was limited by the peak width of the MS signal resulting in an occasional slight overlap between the peaks. Further, relative standard deviation was 10 ± 1% with all tested sampling strategies. Chemical reaction monitoring of DAN to NAT using nitrite was successfully accomplished with 2 s/sample throughout showing almost complete transformation in 10 min with no signal overlap. Conclusions: This work illustrates the development of a noncontact, automated I.DOT/OPSI-MS system with improved throughput achieved through an optimized software interface. Its achievable analysis time and precision make it a viable approach for drug discovery and in situ reaction monitoring studies.

47 OTHER INSTRUMENTATION↗

DOE OSTI2025

Importance of Sample Handling and Preparation for Surface Analysis: A Summary of ISO Standard 20579 Part 1, Documenting and Reporting the Handling of Specimens Prior to Analysis

Reliable and reproducible analysis of surfaces is critically dependent on how samples have been collected, handled, and prepared before analysis. Although there are important, well-established general guidelines to minimize unintended alteration of the surfaces to be analyzed, specific handling steps depend on the nature of the samples and information desired. Assessments of the validity and reliability of the results require adequate information about sampling, handling, and processing. ISO standard 20579 part 1 describes the information to be recorded and reported for samples that are prepared or submitted for surface analysis. This paper summarizes elements of the standard, which includes annexes that justify and inform the sample handling processes. Also included is a checklist of information that needs to be recorded and reported and an appendix containing an example of a form that might be used to report the information.

AES↗

DOE OSTI2025

Evaluation of a high-throughput method for processing sponge-stick samples to detect viable, non-spore-forming biothreat agents

After a bioterrorism incident, surface sampling is often used to determine the extent of contamination and exposure, guiding decontamination efforts and decisions for re-occupancy of affected sites. The sponge-stick (SS) is a preferred and commonly used device for sample collection to detect both spore-forming and non-spore-forming biothreat agents from non-porous surfaces. Here, in this study, a recently developed high-throughput method (HTM) for processing SS samples to detect viable Bacillus anthracis spores was adapted for detection of non-spore-forming biothreat agents, Yersinia pestis and Francisella tularensis. The scalable HTM was used to process up to 20 SS samples simultaneously, compared to the current stomacher-based method which processes one SS at a time. Comparisons of the HTM and the stomacher-based method were statistically indistinguishable for most experiments (P > 0.05) with HTM recoveries of 37–60 % for Y. pestis inoculated at 102–103 cells/SS and held 48 h at 4 °C to mimic sample transport/storage. The HTM was integrated with Rapid Viability-Polymerase Chain Reaction (RV-PCR) analysis to detect viable Y. pestis in the presence of particulate contamination (Arizona Test Dust, ATD). This approach detected Y. pestis inoculated at 20 cells/SS and ATD did not impact detection (P > 0.05). F. tularensis showed significantly lower recoveries between no-hold time and 48-h hold time (4 °C, P < 0.05) using the HTM, which further testing showed could be due to toxicity of the neutralizing buffer used for SS pre-wetting. With modifications, this method could enhance throughput capacity while maintaining similar recovery efficiencies to current methods for other non-spore-forming bacterial pathogens.

Biological and medical sciences↗