Results for “vibrator array” — Page 2

DOE OSTI2015

TU-EF-207-05: Dedicated Cone-beam Breast CT

Breast imaging technology is advancing on several fronts. In digital mammography, the major technological trend has been on optimization of approaches for performing combined mammography and tomosynthesis using the same system. In parallel, photon-counting slot-scan mammography is now in clinical use and more efforts are directed towards further development of this approach for spectral imaging. Spectral imaging refers to simultaneous acquisition of two or more energy-windowed images. Depending on the detector and associated electronics, there are a number of ways this can be accomplished. Spectral mammography using photon-counting detectors can suppress electronic noise and importantly, it enables decomposition of the image into various material compositions of interest facilitating quantitative imaging. Spectral imaging can be particularly important in intravenously injected contrast mammography and eventually tomosynthesis. The various approaches and applications of spectral mammography are discussed. Digital breast tomosynthesis relies on the mechanical movement of the x-ray tube to acquire a number of projections in a predefined arc, typically from 9 to 25 projections over a scan angle of +/−7.5 to 25 degrees depending on the particular system. The mechanical x-ray tube motion requires relatively long acquisition time, typically between 3.7 to 25 seconds depending on the system. Moreover, mechanical scanning may have an effect on the spatial resolution due to internal x-ray filament or external mechanical vibrations. New x-ray source arrays have been developed and they are aimed at replacing the scanned x-ray tube for improved acquisition time and potentially for higher spatial resolution. The potential advantages and challenges of this approach are described. Combination of digital mammography and tomosynthesis in a single system places increased demands on certain functional aspects of the detector and overall performance, particularly in the tomosynthesis mode due to lower photon fluence per projection. This may require fast-frame acquisition and symmetric or asymmetric pixel binning in some systems. Recent studies investigated the performance of increased conversion layer thickness for contrast-enhanced imaging of the breast in dual-energy acquisition mode. In other direct conversion detectors operating in the avalanche mode, sensitivities close to the single photon response are also explored for mammography and breast tomosynthesis. The potential advantages and challenges of this approach are described. Dedicated breast CT brings x-ray imaging of the breast to true tomographic 3D imaging. It can eliminate the tissue superposition problem and does not require physical compression of the breast. Using cone beam geometry and a flat-panel detector, several hundred projections are acquired and reconstructed to near isotropic voxels. Multiplanar reconstruction facilitates viewing the breast volume in any desired orientation. Ongoing clinical studies, the current state-of-the art, and research to advance the technology are described. Learning Objectives: To understand the ongoing developments in x-ray imaging of the breast To understand the approaches and applications of spectral mammography To understand the potential advantages of distributed x-ray source arrays for digital breast tomosynthesis To understand the ongoing developments in detector technology for digital mammography and breast tomosynthesis To understand the current state-of-the-art for dedicated cone-beam breast CT and research to advance the technology. Research collaboration with Koning Corporation.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2015

TU-EF-207-02: Spectral Mammography Based on Photon Counting Detectors

Breast imaging technology is advancing on several fronts. In digital mammography, the major technological trend has been on optimization of approaches for performing combined mammography and tomosynthesis using the same system. In parallel, photon-counting slot-scan mammography is now in clinical use and more efforts are directed towards further development of this approach for spectral imaging. Spectral imaging refers to simultaneous acquisition of two or more energy-windowed images. Depending on the detector and associated electronics, there are a number of ways this can be accomplished. Spectral mammography using photon-counting detectors can suppress electronic noise and importantly, it enables decomposition of the image into various material compositions of interest facilitating quantitative imaging. Spectral imaging can be particularly important in intravenously injected contrast mammography and eventually tomosynthesis. The various approaches and applications of spectral mammography are discussed. Digital breast tomosynthesis relies on the mechanical movement of the x-ray tube to acquire a number of projections in a predefined arc, typically from 9 to 25 projections over a scan angle of +/−7.5 to 25 degrees depending on the particular system. The mechanical x-ray tube motion requires relatively long acquisition time, typically between 3.7 to 25 seconds depending on the system. Moreover, mechanical scanning may have an effect on the spatial resolution due to internal x-ray filament or external mechanical vibrations. New x-ray source arrays have been developed and they are aimed at replacing the scanned x-ray tube for improved acquisition time and potentially for higher spatial resolution. The potential advantages and challenges of this approach are described. Combination of digital mammography and tomosynthesis in a single system places increased demands on certain functional aspects of the detector and overall performance, particularly in the tomosynthesis mode due to lower photon fluence per projection. This may require fast-frame acquisition and symmetric or asymmetric pixel binning in some systems. Recent studies investigated the performance of increased conversion layer thickness for contrast-enhanced imaging of the breast in dual-energy acquisition mode. In other direct conversion detectors operating in the avalanche mode, sensitivities close to the single photon response are also explored for mammography and breast tomosynthesis. The potential advantages and challenges of this approach are described. Dedicated breast CT brings x-ray imaging of the breast to true tomographic 3D imaging. It can eliminate the tissue superposition problem and does not require physical compression of the breast. Using cone beam geometry and a flat-panel detector, several hundred projections are acquired and reconstructed to near isotropic voxels. Multiplanar reconstruction facilitates viewing the breast volume in any desired orientation. Ongoing clinical studies, the current state-of-the art, and research to advance the technology are described. Learning Objectives: To understand the ongoing developments in x-ray imaging of the breast To understand the approaches and applications of spectral mammography To understand the potential advantages of distributed x-ray source arrays for digital breast tomosynthesis To understand the ongoing developments in detector technology for digital mammography and breast tomosynthesis To understand the current state-of-the-art for dedicated cone-beam breast CT and research to advance the technology. Research collaboration with Koning Corporation.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2015

TU-EF-207-01: Introductory Remarks on Recent Advances in Breast Imaging

Breast imaging technology is advancing on several fronts. In digital mammography, the major technological trend has been on optimization of approaches for performing combined mammography and tomosynthesis using the same system. In parallel, photon-counting slot-scan mammography is now in clinical use and more efforts are directed towards further development of this approach for spectral imaging. Spectral imaging refers to simultaneous acquisition of two or more energy-windowed images. Depending on the detector and associated electronics, there are a number of ways this can be accomplished. Spectral mammography using photon-counting detectors can suppress electronic noise and importantly, it enables decomposition of the image into various material compositions of interest facilitating quantitative imaging. Spectral imaging can be particularly important in intravenously injected contrast mammography and eventually tomosynthesis. The various approaches and applications of spectral mammography are discussed. Digital breast tomosynthesis relies on the mechanical movement of the x-ray tube to acquire a number of projections in a predefined arc, typically from 9 to 25 projections over a scan angle of +/−7.5 to 25 degrees depending on the particular system. The mechanical x-ray tube motion requires relatively long acquisition time, typically between 3.7 to 25 seconds depending on the system. Moreover, mechanical scanning may have an effect on the spatial resolution due to internal x-ray filament or external mechanical vibrations. New x-ray source arrays have been developed and they are aimed at replacing the scanned x-ray tube for improved acquisition time and potentially for higher spatial resolution. The potential advantages and challenges of this approach are described. Combination of digital mammography and tomosynthesis in a single system places increased demands on certain functional aspects of the detector and overall performance, particularly in the tomosynthesis mode due to lower photon fluence per projection. This may require fast-frame acquisition and symmetric or asymmetric pixel binning in some systems. Recent studies investigated the performance of increased conversion layer thickness for contrast-enhanced imaging of the breast in dual-energy acquisition mode. In other direct conversion detectors operating in the avalanche mode, sensitivities close to the single photon response are also explored for mammography and breast tomosynthesis. The potential advantages and challenges of this approach are described. Dedicated breast CT brings x-ray imaging of the breast to true tomographic 3D imaging. It can eliminate the tissue superposition problem and does not require physical compression of the breast. Using cone beam geometry and a flat-panel detector, several hundred projections are acquired and reconstructed to near isotropic voxels. Multiplanar reconstruction facilitates viewing the breast volume in any desired orientation. Ongoing clinical studies, the current state-of-the art, and research to advance the technology are described. Learning Objectives: To understand the ongoing developments in x-ray imaging of the breast To understand the approaches and applications of spectral mammography To understand the potential advantages of distributed x-ray source arrays for digital breast tomosynthesis To understand the ongoing developments in detector technology for digital mammography and breast tomosynthesis To understand the current state-of-the-art for dedicated cone-beam breast CT and research to advance the technology. Research collaboration with Koning Corporation.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2022

Synthesis of bacteriochlorins bearing diverse β-substituents

Synthetic bacteriochlorins, analogues of native bacteriochlorophylls, provide absorption in the near-infrared spectral region and hence are valuable for fundamental studies in photochemistry and applications ranging from solar energy conversion to photomedicine. The full realization of such opportunities hinges on access to synthetically malleable bacteriochlorins. Here, two established routes that rely on self-condensation of a dihydrodipyrrin-acetal or dihydrodipyrrin-carboxaldehyde have been exploited to prepare 6 bacteriochlorins (2 new, 4 known in improved fashion). Each bacteriochlorin contains a gem-dimethyl group in the reduced, pyrroline ring to ensure stability toward adventitious dehydrogenation. These and related synthetic bacteriochlorins have been derivatized to tailor the perimeter of the macrocycle with diverse groups, affording 9 additional new bacteriochlorins and 4 known bacteriochlorins. By direct installation and/or derivatization, the scope of attached entities in this collection includes alkyl, amino, aryl, bromo, carboethoxy, oxo, phenylethynyl, and pyridyl. Furthermore, the bacteriochlorins are suited for surface attachment, bioconjugation, water-solubilization, vibrational studies, and elaboration into multichromophore arrays. Altogether the synthesis of 25 new compounds (11 bacteriochlorins, 14 precursors) is described.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

DOE OSTI2017

An Experimental Investigation of Distributed Acoustic Sensing (DAS) on Lake Ice

A vibration-sensitive, Distributed Acoustic Sensor (DAS) array, using fiber-optic cables, was deployed in a triangularly shaped geometry on the frozen surface of Lake Mendota in Madison, Wisconsin, USA. The purpose of the array and testing program was to analyze the DAS response and to utilize the high spatial density of the distributed array for system response characterization in a well-constrained, small, surface array. A geophone array was also deployed to provide a reference system. The design of the array allowed us to assess the response of DAS with respect to distance from the seismic sources, the degradation of the response with length of the cable, the directivity of the fiber response with respect of the direction of the particle motion, and the quality of the signal with respect to cable type. The DAS array was examined for different cable constructions and orientations relative to the source propagation direction. Tight-buffered and loose-tube fiber-optic cable constructions were used, with both having good signal responses when well-coupled to the ice. In general, the tight-buffered cable was better suited for DAS applications. Directional sensitivity of the DAS was also inspected for several directions of wave propagation and particle motion. The results showed that the strongest DAS signals were recorded when the direction of the fiber was oriented parallel to the direction of particle motion. Lastly, the DAS and geophone data sets were examined together to qualitatively determine, in conjunction with established DAS best practices, how the high spatial density offered by DAS could improve results over traditional point sensor arrays in certain situations.

15 GEOTHERMAL ENERGY↗

DOE OSTI2020

Using Geophysical Technologies Deployed in Inexpensive Monitoring Wells to Monitor the Evolution of a CO 2 Plume: Potential Benefits and R&D Needs

This report demonstrates the potential benefits of an R&D program designed to substantially decrease the cost of drilling monitoring wells. The study determines the costs of monitoring a commercial-scale CO 2 storage project's CO 2 plume using a vertical seismic profile (VSP) array. The VSP array consists of permanent surface orbital vibrator (SOV) seismic sources and distributed acoustic sensing (DAS) fiber optic cable receivers permanently installed in shallow monitoring wells. Several scenarios are assessed varying the costs of drilling monitoring wells for DAS to evaluate the potential benefits of an R&D program to lower well costs. The monitoring costs of VSP are compared against those of 4-D seismic surveys which deploy temporary seismic sources and receivers. If the cost of monitoring wells can be lowered about 50%, VSP monitoring is a more attractive cost option than 4-D seismic for CO 2 plume monitoring, warranting future R&D efforts to lower these costs.

58 GEOSCIENCES↗

DOE OSTI2021

Intelligent Monitoring Systems and Advanced Well Integrity and Mitigation

Long-term seismic monitoring of carbon capture and storage projects is needed to verify that the injected gas is safely stored in the subsurface until permanence can be assured. Conventional surface seismic monitoring techniques are usually expensive, require highly invasive surface operations, and need significant time investments on the part of personnel for both the field effort and processing the acquired data. For these reasons, permanent reservoir monitoring technologies are preferred, as they can offer a cost-effective solution for long-term monitoring. As part of the monitoring program of the Archer Daniels Midland’s large-scale injection of CO 2 in Decatur, Illinois, USA, a continuous seismic monitoring array was installed using a combination of surface orbital vibrator (SOV) sources and fiber-optic cables for distributed acoustic sensing (DAS) acquisition with the objective to build a continuous monitoring array. The aim of the presented project was to build a monitoring array and platform that integrates real-time seismic data with conventional data streams and provides continuous data analysis using dynamic computational models to deliver a comprehensive real-time assessment of subsurface conditions. It is in this context that the Intelligent Monitoring Systems and Advanced Well Integrity and Mitigation project was proposed with the objective to develop an integrated architecture that utilizes a permanent seismic monitoring network, combines the real-time geophysical and process data with reservoir flow and geomechanical models to create a comprehensive monitoring, visualization, and control system that delivers critical information for process surveillance and optimization.

54 ENVIRONMENTAL SCIENCES↗

DOE OSTI2023

Defect‐Free Sound Insulator Using Single Metal‐Based Friction Stir Process Array

Metals are excellent conductors for phonon transportation such as vibration, sound, and heat. Generally, metal sound insulators require multimaterial structure or defects and unimetal sound insulators are challenging. Therefore, a design of a defect-free sound insulator made by single alloys with multiple friction stir processes (FSPs) is proposed. Periodic friction stir processing can induce superlattice-like local mechanical properties’ modifications. By experimental acoustic characterization, it is observed that FSP can introduce clear acoustic–elastic property contrast on an aluminum plate by the presence of stir zone and heat-affected zones. In numerical simulations, the signature FSP-induced property profile is periodically and parallelly arranged on a long aluminum plate. The transmission gap frequencies are present on the frequency spectrum with the sound propagation direction perpendicular to the FSP paths. Disorder offsets on FSP periodicity are further introduced. Anderson localization is found on a resonance frequency, which provides −11 dB sound reduction by an exponential decay. Due to the finite design length, the slight disorder can also enhance sound insulation in the periodic transmission gap frequency. In conclusion, with analysis and comparison with different configurations, the best performance in the models can achieve −30 dB sound insulation in the 350 mm-long aluminum alloy plate with 14 parallel FSPs.

36 MATERIALS SCIENCE↗

DOE OSTI2019

First observation of γ -soft and triaxial bands in Zr isotopes

New results obtained in this work from measurements of γ radiation following fission of 248 Cm and 252 Cf, performed using Eurogam2 and Gammasphere arrays, respectively, reveal excitations corresponding to γ vibrations and triaxial deformation present in 100 Zr and 102 Zr nuclei. This is the first observation of nonaxial bands in Zr isotopes. Such excitations probably occur due to competing prolate and oblate configurations, identified recently in these nuclei. Evolution of γ softness and triaxiality in Zr isotopes is observed in the function of the neutron number.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗

DOE OSTI2017

An experimental topographic amplification study at Los Alamos National Laboratory using ambient vibrations

An experimental study aimed at investigating potential topographic amplification of seismic waves was conducted on a 50-m-tall and 185-m-wide soft-rock ridge located at Los Alamos National Laboratory near Los Alamos, New Mexico. Ten portable broadband seismograph stations were placed in arrays across the ridge and left to record ambient vibration data for ~9 hours. Clear evidence of topographic amplification was observed by comparing spectral ratios calculated from ambient noise recordings at the toe, slope, and crest of the instrumented ridge. The inferred resonance frequency of the ridge obtained from the experimental recordings was found to agree well with several simple estimates of the theoretical resonance frequency based on its geometry and stiffness. Results support the feasibility of quantifying the frequency range of topographic amplification solely using ambient vibrations, rather than strong or weak ground motions. Additionally, comparisons have been made between a number of widely used experimental methods for quantifying topographic effects, such as the standard spectral ratio, median reference method, and horizontal-to-vertical spectral ratio. As a result, differences in the amplification and frequency range of topographic effects indicated by these methods highlight the importance of choosing a reference condition that is appropriate for the site-specific conditions and goals associated with an experimental topographic amplification study.

58 GEOSCIENCES↗

DOE OSTI2022

Resolved rotation–vibration non-equilibrium with rotational VIPA-CARS

Simultaneous rotational and vibrational temperatures are measured in an N 2 plasma with rotational coherent anti-Stokes Raman scattering (CARS) resolved with a virtually imaged phased array (VIPA)-based spectrometer. A VIPA spectrally separates rotational transitions for each vibrational state, allowing vibrational populations to be directly measured. VIPA-CARS is shown to provide more accurate measurements of non-equilibrium temperatures than grating-resolved rotational CARS. The general characteristics, limitations, and potential uses of VIPA-CARS are discussed.

Steinmetz, S. A. (ORCID:0000000311014662)↗

DOE OSTI2019

Progress in Development of Electrochemical Methods in Corrosion Science and Engineering

The role and impact of four electrochemical techniques in the study of various corrosion applications are discussed, these are: scanning vibrating electrode technique (SVET), coupled multi-electrode array (CMEA) technique, scanning electrochemical microscope (SECM) and atomic emission spectroelectrochemistry (AESEC). A common theme is an ability to monitor corrosion phenomena in situ on a local electrochemical scale with high resolution of electrochemical and, in some cases, chemical reaction rates. In all cases, the techniques presented here are discussed in the context of specific corrosion problems carried out in full immersion conditions. Examples taken from the current literature, and new data, are presented to demonstrate the use and advantages of these techniques, or a combination of these techniques, as powerful tools for industrially important applications. Here, this includes: assessment of the galvanic interactions and throwing-power of metal-rich primer coatings for active corrosion protection, corrosion/corrosion resistance mechanisms of new metal alloys, the effect of pretreatments on coating integrity, current distributions within a crevice and pitting corrosion.

AESEC↗

DOE OSTI2015

Si-BEARING MOLECULES TOWARD IRC+10216: ALMA UNVEILS THE MOLECULAR ENVELOPE OF CWLeo

We report the detection of SiS rotational lines in high-vibrational states as well as SiO and SiC{sub 2} lines in their ground vibrational state toward IRC+10216 during the Atacama Large Millimeter Array Cycle 0. The spatial distribution of these molecules shows compact emission for SiS and a more extended emission for SiO and SiC{sub 2} and also proves the existence of an increase in the SiC{sub 2} emission at the outer shells of the circumstellar envelope (CSE). We analyze the excitation conditions of the vibrationally excited SiS using the population diagram technique, and we use a large velocity gradient model to compare with the observations. We found moderate discrepancies between the observations and the models that could be explained if SiS lines detected are optically thick. Additionally, the line profiles of the detected rotational lines in the high-energy vibrational states show a decreasing linewidth with increasing energy levels. This may be evidence that these lines could be excited only in the inner shells, i.e., the densest and hottest, of the CSE of IRC+10216.

79 ASTRONOMY AND ASTROPHYSICS↗

DOE OSTI2015

The resilient hybrid fiber sensor network with self-healing function

This paper presents a novel resilient fiber sensor network (FSN) with multi-ring architecture, which could interconnect various kinds of fiber sensors responsible for more than one measurands. We explain how the intelligent control system provides sensors with self-healing function meanwhile sensors are working properly, besides each fiber in FSN is under real-time monitoring. We explain the software process and emergency mechanism to respond failures or other circumstances. To improve the efficiency in the use of limited spectrum resources in some situations, we have two different structures to distribute the light sources rationally. Then, we propose a hybrid sensor working in FSN which is a combination of a distributed sensor and a FBG (Fiber Bragg Grating) array fused in a common fiber sensing temperature and vibrations simultaneously with neglectable crosstalk to each other. By making a failure to a working fiber in experiment, the feasibility and effectiveness of the network with a hybrid sensor has been demonstrated, hybrid sensors could not only work as designed but also survive from destructive failures with the help of resilient network and smart and quick self-healing actions. The network has improved the viability of the fiber sensors and diversity of measurands.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

DOE OSTI2019

Does the Hood Canal Bridge traffic noise affect migrating steelhead smolts?

Recent research conducted by NOAA’s Manchester Research Laboratory has provided strong evidence of a substantial migration interference and increased mortality risk associated with the Hood Canal Bridge , which drives the need to investigate the sound and vibration generated by the vehicles crossing the bridge. A month-long monitoring of in-water sound pressure and the vibration of the bridge pontoons was performed at the Hood Canal Bridge by three sets of autonomous sound and vibration recording systems deployed along the bridge. At each deployment site, sound pressure in water was recorded by a hydrophone submerged three meters under water, and the vibration of the bridge pontoon was recorded by an array of three orthogonally mounted single-axis accelerometers. Both sound pressure and acceleration data were analyzed and compared to the threshold levels suggested by previous studies. Results show that the observed sound pressure levels and particle accelerations are strongly correlated with traffic volume across the bridge, and particle accelerations occasionally exceeded the threshold levels that could elicit the avoidance behavior of juvenile salmon. It is concluded that the Hood Canal Bridge traffic noise can potentially affect migrating salmonids due to the intense particle accelerations caused by the bridge pontoons in water.

Zang, Xiaoqin↗

DOE OSTI2019

Design, Fabrication, and Characterization of a Piezoelectric AFM Cantilever Array

Atomic force microscope (AFM) is a powerful instrument, which has been successfully employed in a myriad of applications from imaging to lithography, over the last decades. Despite its widespread use, low throughput of the AFM remains one of its major limitations along with slow scan rates in tapping mode. In this work, we propose a microfabricated cantilever array composed of five cantilevers, each equipped with onchip piezoelectric displacement sensors and an actuator for parallel imaging in tapping mode. The cantilevers are designed to have separate resonance frequencies in order to effectively minimize the vibrational coupling. The measured resonance frequencies range from 85.34 kHz to 107.78 kHz, and more than 5 kHz resonant frequency separation is achieved in the neighboring cantilevers. Vibrational coupling is mitigated by over two orders of magnitude compared to arrays with identical cantilevers. The common feedthrough problem in this type of active system is addressed by configuring the displacement sensors differentially. Finally, one of the cantilevers in the arrayis successfully employed for tapping mode AFM imaging.

42 ENGINEERING↗

DOE OSTI2021

Understanding Spin Coherence in Polyoxometalate-Based Molecular Qubits

This research advances the understanding of spin decoherence mechanisms and addresses the grand challenges in quantum information science of generating and stabilizing quantum states that may be manipulated with single-atom precision. It is accomplished using unique capabilities developed at PNNL for ion soft landing and spatially resolved vibrational spectroscopy of well-defined supported molecular qubit (MQ) arrays. It addresses knowledge gaps impeding the development of MQ-based quantum devices by answering two scientific questions: 1) Can we minimize spin-lattice relaxation rates by tuning the substrate-MQ interface? 2) What is the optimum number of spin centers that enables sufficient coherent signal generation prior to decoherence through inter-MQ and MQ-support interactions? The objective is to develop predictive design principles for prolonging spin coherence lifetimes in arrays of optically-addressable MQs for quantum computing applications.

97 MATHEMATICS AND COMPUTING↗

DOE OSTI2020

Fibre-optic based DAS technology for Long-term Seismic Monitoring of Carbon Capture and Storage Projects

Long-term seismic monitoring of carbon capture and storage projects (CCS) is needed to verify that the injected gas is safely stored in the subsurface until permanence can be assured. Conventional surface seismic monitoring techniques are usually expensive, require highly invasive surface operations, and need significant time investments on the part of personnel for both the field effort and processing the acquired data. For these reasons, permanent reservoir monitoring (PRM) technologies are preferred, as they can offer a cost-effective solution for long-term monitoring. In this context, we have developed and trialed the use of distributed acoustic sensing (DAS) coupled to permanent rotary sources, called surface orbital vibrators (SOV), with the objective to build a continuous monitoring array for CCS projects.

47 OTHER INSTRUMENTATION↗