Experimental Method Development to Evaluate Cements at Elevated Pressure and Temperature.
Abstract not provided.
Bauer, Stephen J.↗
SEARCH · Engineering Papers
Results for “Experimental Methods”
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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An Experimental Method To Determine The Contact Thermal Resistance Of PCM Materials Undergoing Large Volume Change
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Rendall, Joe↗
Experimental Methods to Estimate Accumulated Solids in Nuclear Waste Tanks - 13313
The Department of Energy has a large number of nuclear waste tanks. It is important to know if fissionable materials can concentrate when waste is transferred from staging tanks prior to feeding waste treatment plants. Specifically, there is a concern that large, dense particles, e.g., plutonium containing, could accumulate in poorly mixed regions of a blend tank heel for tanks that employ mixing jet pumps. At the request of the DOE Hanford Tank Operations Contractor, Washington River Protection Solutions, the Engineering Development Laboratory of the Savannah River National Laboratory performed a scouting study in a 1/22-scale model of a waste tank to investigate this concern and to develop measurement techniques that could be applied in a more extensive study at a larger scale. Simulated waste tank solids and supernatant were charged to the test tank and rotating liquid jets were used to remove most of the solids. Then the volume and shape of the residual solids and the spatial concentration profiles for the surrogate for plutonium were measured. This paper discusses the overall test results, which indicated heavy solids only accumulate during the first few transfer cycles, along with the techniques and equipment designed and employed in the test. Those techniques include: - Magnetic particle separator to remove stainless steel solids, the plutonium surrogate from a flowing stream. - Magnetic wand used to manually remove stainless steel solids from samples and the tank heel. - Photographs were used to determine the volume and shape of the solids mounds by developing a composite of topographical areas. - Laser range finders to determine the volume and shape of the solids mounds. - Core sampler to determine the stainless steel solids distribution within the solids mounds. - Computer driven positioner that placed the laser range finders and the core sampler over solids mounds that accumulated on the bottom of a scaled staging tank in locations where jet velocities were low. These devices and techniques were very effective to estimate the movement, location, and concentrations of the solids representing plutonium and are expected to perform well at a larger scale. The operation of the techniques and their measurement accuracies will be discussed as well as the overall results of the accumulated solids test. (authors)
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
Multi–length scale characterization of point defects in thermally oxidized, proton irradiated iron oxides
A key for the success of safe nuclear power generation system is to consider structural materials that are economical, meet mechanical property needs, possess good corrosion resistance, and are radiation tolerant. Nevertheless, fundamental insights that elucidate the details of radiation damage on materials corrosion performance are lacking. This includes the behavior of surface oxides which often regulate corrosion. For example, it is unclear how non-equilibrium point defects, oxide structure, mass transport in oxides, and subsequent oxidation behavior are altered by the radiation. Here, in this work, some of the effects of proton irradiation on the attributes of point defects, iron oxide microstructures, and the physical nature of the oxidation product were correlated with corrosion behavior. Iron oxides, fabricated by thermal oxidation in air at 400°C and 800°C for 1 h, were subjected to 200 keV, 0.03 dpa (displacements per atom) of proton irradiation, and subjected to corrosion reactivity assessment using AC and DC electrochemical methods. Experimental methods that target materials information at different length scales, such as positron annihilation spectroscopy (atomistic), transmission electron microscopy (mesoscopic), and electrochemical methods (macroscopic), were coupled to shed light on the impact of radiation-induced defect modifications and structural changes in oxides on corrosion reactivity which ultimately affects durability in harsh environments.
36 MATERIALS SCIENCE↗
Theoretical and experimental physical methods of neutron-capture therapy
This review is based to a substantial degree on our priority developments and research at the IR-8 reactor of the Russian Research Centre Kurchatov Institute. New theoretical and experimental methods of neutron-capture therapy are developed and applied in practice; these are: A general analytical and semi-empiric theory of neutron-capture therapy (NCT) based on classical neutron physics and its main sections (elementary theories of moderation, diffuse, reflection, and absorption of neutrons) rather than on methods of mathematical simulation. The theory is, first of all, intended for practical application by physicists, engineers, biologists, and physicians. This theory can be mastered by anyone with a higher education of almost any kind and minimal experience in operating a personal computer. Methods: of phantom experimental studies for the semi-empiric theory of NCT using epithermal neutrons. Experimental methods for measuring and monitoring the spectral composition of therapeutic, research, and analytical neutron beams for NCT and other investigations with neutrons. Experimental methods of remote neutron dosimetry of biological objects with intentional modification of the element composition of tissues in NCT. Methods: of mass investigations in pharmacokinetics and biologic efficiency of novel dose-forming preparations. Methods: for tailoring of therapeutic, research, and analytical neutron beams for NCT and other investigations with neutrons. Methods: of capillary neutron optics application for NCT and other fundamental and applied studies with neutrons.
62 RADIOLOGY AND NUCLEAR MEDICINE↗
A novel method for experimental characterization of large-angle scattered particles in scanned carbon-ion therapy
Purpose: It is essential to consider large-angle scattered particles in dose calculation models for therapeutic carbon-ion beams. However, it is difficult to measure the small dose contribution from large-angle scattered particles. In this paper, the authors present a novel method to derive the parameters describing large-angle scattered particles from the measured results. Methods: The authors developed a new parallel-plate ionization chamber consisting of concentric electrodes. Since the sensitive volume of each channel is increased linearly with this type, it is possible to efficiently and easily detect small contributions from the large-angle scattered particles. The parameters describing the large-angle scattered particles were derived from pencil beam dose distribution in water measured with the new ionization chamber. To evaluate the validity of this method, the correction for the field-size dependence of the doses, “predicted-dose scaling factor,” was calculated with the new parameters. Results: The predicted-dose scaling factor calculated with the new parameters was compared with the existing one. The difference between the new correction factor and the existing one was 1.3%. For target volumes of different sizes, the calculated dose distribution with the new parameters was in good agreement with the measured one. Conclusions: Parameters describing the large-angle scattered particles can be efficiently and rapidly determined using the new ionization chamber. The authors confirmed that the field-size dependence of the doses could be compensated for by the new parameters. This method makes it possible to easily derive the parameters describing the large-angle scattered particles, while maintaining the dose calculation accuracy.
61 RADIATION PROTECTION AND DOSIMETRY↗
Sr{sub 4}Ru{sub 6}ClO{sub 18}, a new Ru{sup 4+/5+} oxy-chloride, solved by precession electron diffraction: Electric and magnetic behavior
The crystal structure of Sr{sub 4}Ru{sub 6}ClO{sub 18}, a new Ru{sup 4+/5+} oxo-chloride, has been determined from Precession Electron Diffraction (PED) data acquired on a nanocrystal in a transmission electron microscope using the technique of electron diffraction tomography. This approach is described in details following a pedagogic route and a systematic comparison is made of this rather new method with other experimental methods of electron diffraction, and with the standard single crystal X-ray diffraction technique. Both transport and magnetic measurements, showed a transition at low temperature that may be correlated to Ru{sup 4+}/Ru{sup 5+} charge ordering. - Graphical abstract: Structure of Sr{sub 4}Ru{sub 6}ClO{sub 18}, determined using Precession Electron Diffraction data. - Highlights: • Structure of Sr{sub 4}Ru{sub 6}ClO{sub 18} was solved ab initio using precession electron diffraction. • This was done both on a nanometric sample and on a micrometric one. • Different type of experimental methods of electron diffraction are compared. • Single crystal X-ray diffraction was used to confirm the results. • Transport properties were characterized and show “exotic” behavior.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
Electrochemical Stability of Li 10 GeP 2 S 12 and Li 7 La 3 Zr 2 O 12 Solid Electrolytes
The electrochemical stability window of solid electrolyte is overestimated by the conventional experimental method using a Li/electrolyte/inert metal semiblocking electrode because of the limited contact area between solid electrolyte and inert metal. Since the battery is cycled in the overestimated stability window, the decomposition of the solid electrolyte at the interfaces occurs but has been ignored as a cause for high interfacial resistances in previous studies, limiting the performance improvement of the bulk-type solid-state battery despite the decades of research efforts. Thus, there is an urgent need to identify the intrinsic stability window of the solid electrolyte. The thermodynamic electrochemical stability window of solid electrolytes is calculated using first principles computation methods, and an experimental method is developed to measure the intrinsic electrochemical stability window of solid electrolytes using a Li/electrolyte/electrolyte-carbon cell. The most promising solid electrolytes, Li10GeP2S12 and cubic Li-garnet Li7La3Zr2O12, are chosen as the model materials for sulfide and oxide solid electrolytes, respectively. The results provide valuable insights to address the most challenging problems of the interfacial stability and resistance in high-performance solid-state batteries.
25 ENERGY STORAGE↗
Full observation of ultrafast cascaded radiationless transitions from S{sub 2}(ππ{sup ∗}) state of pyrazine using vacuum ultraviolet photoelectron imaging
A photoexcited molecule undergoes multiple deactivation and reaction processes simultaneously or sequentially, which have been observed by combinations of various experimental methods. However, a single experimental method that enables complete observation of the photo-induced dynamics would be of great assistance for such studies. Here we report a full observation of cascaded electronic dephasing from S{sub 2}(ππ{sup *}) in pyrazine (C{sub 4}N{sub 2}H{sub 4}) by time-resolved photoelectron imaging (TRPEI) using 9.3-eV vacuum ultraviolet pulses with a sub-20 fs time duration. While we previously demonstrated a real-time observation of the ultrafast S{sub 2}(ππ{sup *}) → S{sub 1}(nπ{sup *}) internal conversion in pyrazine using TRPEI with UV pulses, this study presents a complete observation of the dynamics including radiationless transitions from S{sub 1} to S{sub 0} (internal conversion) and T{sub 1}(nπ{sup *}) (intersystem crossing). Also discussed are the role of {sup 1}A{sub u}(nπ{sup *}) in the internal conversion and the configuration interaction of the S{sub 2}(ππ{sup *}) electronic wave function.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
Vapor-Liquid Equilibrium of the Ethylene–Butane Mixture
The article deals with the investigation of the ethylene-butane natural gases mixture that is promising for practical application. A unit with a small volume cell created to obtain data on phase equilibria and thermal properties of binary mixtures of little investigated and rare substances using several experimental methods was presented. It is shown that it was possible to use non-standard measuring equipment to obtain sufficiently reliable results in a wide range of temperatures, pressures and compositions. Application of a new method to determine two-component gas mixtures concentration was demonstrated. The method of experimentation was described as well. The experimental results of ethylene–butane mixture thermal properties and vapor-liquid equilibrium that have expanded our knowledge in relation to this two-component natural refrigerant behavior in the low-temperature region and at high dilutions were tabulated. The comparison of the experimental and calculated data showed the possibility of applying the three-parameter cubic equation of state to simulate the thermodynamic properties of the ethylene–butane mixture without using test data of the mixture.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
PreDSLpmo: A neural network-based prediction tool for functional annotation of lytic polysaccharide monooxygenases
Lytic polysaccharide monooxygenases (LPMOs), a family of copper-dependent oxidative enzymes, boost the degradation of polysaccharides such as cellulose, chitin, and others. While experimental methods are used to validate LPMO function, a computational method that can aid experimental methods and provide fast and accurate classification of sequences into LPMOs and its families would be an important step towards understanding the breadth of contributions these enzymes make in deconstruction of recalcitrant polysaccharides. In this study, we developed a machine learning-based tool called PreDSLpmo that employs two different approaches to functionally classify protein sequences into the major LPMO families (AA9 and AA10). The first approach uses a traditional neural network or multilayer percerptron-based approach, while the second employs bi-directional long short-term memory for sequence classification. Finally, our method shows improvement in predictive power when compared with dbCAN2, an existing HMM-profile-based CAZyme predicting tool, on both validation and independent benchmark set.
59 BASIC BIOLOGICAL SCIENCES↗
Substrate binds in the S1 site of the F253A mutant of LeuT, a neurotransmitter sodium symporter homologue
LeuT serves as the model protein for understanding the relationships between structure, mechanism and pharmacology in neurotransmitter sodium symporters (NSSs). At the present time, however, there is a vigorous debate over whether there is a single high-affinity substrate site (S1) located at the original, crystallographically determined substrate site or whether there are two high-affinity substrates sites, one at the primary or S1 site and the other at a second site (S2) located at the base of the extracellular vestibule. In an effort to address the controversy over the number of high-affinity substrate sites in LeuT, one group studied the F253A mutant of LeuT and asserted that in this mutant substrate binds exclusively to the S2 site and that 1 mM clomipramine entirely ablates substrate binding to the S2 site. Here we study the binding of substrate to the F253A mutant of LeuT using ligand binding and X-ray crystallographic methods. Both experimental methods unambiguously show that substrate binds to the S1 site of the F253A mutant and that binding is retained in the presence of 1 mM clomipramine. These studies, in combination with previous work, are consistent with a mechanism ofr LeuT that involves a single high-affinity substrate binding site.
59 BASIC BIOLOGICAL SCIENCES↗
2010 Ceramics, Solid State Studies in Gordon Research Conference
The 2010 Gordon Conference on Solid State Studies in Ceramics will present forefront research on ceramic materials in energy conversion, storage, and environmental sustainability. Oxide materials in advanced Li-ion batteries will be featured, including first principles computational methods, new experimental methods, novel synthesis, and the design of batteries that exploit nanoscale cathode materials. Several speakers address advances in oxides for solar applications, including photo-catalysts for solar hydrogen production and dye sensitized solar cells, along with thin film photovoltaics. Fast ionic conducting ceramics in electrochemical energy conversion and storage will be addressed for fuel cells and electrochemical storage. New concepts for electrochemical capacitor materials will be addressed, as will thermoelectric, geopolymers, and ceramics in nuclear energy. The Conference will bring together investigators at the forefront of their field as well as junior scientists in a collegial atmosphere, with programmed discussion sessions and informal gatherings in the afternoons and evenings. Poster presentations provide opportunities for junior scientists and graduate students to present their work and exchange ideas with leaders in the field. This Conference provides an avenue for scientists from different disciplines to explore new ideas and promotes cross-disciplinary collaborations in the various research areas represented.
08 HYDROGEN↗
Calibration of measurement sensitivities of multiple micro-cantilever dynamic modes in atomic force microscopy using a contact detection method
An accurate experimental method is proposed for on-spot calibration of the measurement sensitivities of multiple micro-cantilever dynamic modes in atomic force microscopy. One of the key techniques devised for this method is a reliable contact detection mechanism that detects the tip-surface contact instantly. At the contact instant, the oscillation amplitude of the tip deflection, converted to that of the deflection signal in laser reading through the measurement sensitivity, exactly equals to the distance between the sample surface and the cantilever base position. Therefore, the proposed method utilizes the recorded oscillation amplitude of the deflection signal and the base position of the cantilever at the contact instant for the measurement sensitivity calibration. Experimental apparatus along with various signal processing and control modules was realized to enable automatic and rapid acquisition of multiple sets of data, with which the calibration of a single dynamic mode could be completed in less than 1 s to suppress the effect of thermal drift and measurement noise. Calibration of the measurement sensitivities of the first and second dynamic modes of three micro-cantilevers having distinct geometries was successfully demonstrated. The dependence of the measurement sensitivity on laser spot location was also experimentally investigated. Finally, an experiment was performed to validate the calibrated measurement sensitivity of the second dynamic mode of a micro-cantilever.
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
Method of Experimental Research of Long-Range Interactions in Smoky Plasmas
This work offers a method of experimental research of mechanisms of of metal oxides charged condensed grains interaction in smoky plasma containing lightly ionized admixture of alkali metal atoms in gas phase. Describes the hardware-software complex TERM.
70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
Improved deuteron elastic breakup energy dependence via the continuum-discretized coupled-channels method
Experimental elastic-scattering angular distributions for deuteron interaction with {sup 63}Cu and {sup 93}Nb targets are compared with calculations performed within the continuum-discretized coupled-channels (CDCC) method, in which coupling to breakup channels is explicitly taken into account. The calculated elastic breakup cross sections are compared with the predictions of an empirical parametrization for a wide range of deuteron incident energies. The good agreement between the calculations and the systematics at the energies where data are available indicates that the CDCC method permits a useful assessment of empirical parametrizations and provides useful guidance for the extrapolation of these parametrizations beyond the energies formerly considered.
73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
Reducing the effects of acoustic heterogeneity with an iterative reconstruction method from experimental data in microwave induced thermoacoustic tomography
Purpose: An iterative reconstruction method has been previously reported by the authors of this paper. However, the iterative reconstruction method was demonstrated by solely using the numerical simulations. It is essential to apply the iterative reconstruction method to practice conditions. The objective of this work is to validate the capability of the iterative reconstruction method for reducing the effects of acoustic heterogeneity with the experimental data in microwave induced thermoacoustic tomography. Methods: Most existing reconstruction methods need to combine the ultrasonic measurement technology to quantitatively measure the velocity distribution of heterogeneity, which increases the system complexity. Different to existing reconstruction methods, the iterative reconstruction method combines time reversal mirror technique, fast marching method, and simultaneous algebraic reconstruction technique to iteratively estimate the velocity distribution of heterogeneous tissue by solely using the measured data. Then, the estimated velocity distribution is used subsequently to reconstruct the highly accurate image of microwave absorption distribution. Experiments that a target placed in an acoustic heterogeneous environment are performed to validate the iterative reconstruction method. Results: By using the estimated velocity distribution, the target in an acoustic heterogeneous environment can be reconstructed with better shape and higher image contrast than targets that are reconstructed with a homogeneous velocity distribution. Conclusions: The distortions caused by the acoustic heterogeneity can be efficiently corrected by utilizing the velocity distribution estimated by the iterative reconstruction method. The advantage of the iterative reconstruction method over the existing correction methods is that it is successful in improving the quality of the image of microwave absorption distribution without increasing the system complexity.
60 APPLIED LIFE SCIENCES↗
Two–Photon Polymerized Shape Memory Microfibers: A New Mechanical Characterization Method in Liquid
Two-photon polymerization (TPP) is widely used to create 3D micro- and nanoscale scaffolds for biological and mechanobiological studies, which often require the mechanical characterization of the TPP fabricated structures. To satisfy physiological requirements, most of the mechanical characterizations need to be conducted in liquid. However, previous characterizations of TPP fabricated structures are all conducted in air due to the limitation of conventional micro- and nanoscale mechanical testing methods. In this study, a new experimental method is reported for testing the mechanical properties of TPP-printed microfibers in liquid. The experiments show that the mechanical behaviors of the microfibers tested in liquid are significantly different from those tested in air. By controlling the TPP writing parameters, the mechanical properties of the microfibers can be tailored over a wide range to meet a variety of mechanobiology applications. In addition, it is found that, in water, the plasticly deformed microfibers can return to their predeformed shape after tensile strain is released. The shape recovery time is dependent on the size of microfibers. The experimental method represents a significant advancement in mechanical testing of TPP fabricated structures and may help release the full potential of TPP fabricated 3D tissue scaffolds for mechanobiological studies.
36 MATERIALS SCIENCE↗