Results for “Operating Mode” — Page 56

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-207-03: Advances in Stationary Breast Tomosynthesis Using Distributed X-Ray Sources

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-207-04: Advances in Detector Technology for Breast Tomosynthesis

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-207-05: 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 OSTI2020

High Dynamic Voltage Range Studies of Piezoelectric Multilayer Actuators at Low Temperatures

Piezo actuators are used for resonance control in superconducting linacs. In high accelerating gradients linacs, such as those operated in a pulsed mode, the piezos require a large operating voltage. This is due to the Lorentz forced detuning which causes a large frequency shift and is compensated with an active piezo-tuning system. In this high dynamic voltage range the piezo is expected to warm up drastically due to it being in an insulated vacuum. This study characterizes the dielectric properties (capacitance, dielectric losses), the piezo stroke (from geophone), and thermal properties such as heating. Results obtained in the temperature range of 20K to 300K will be presented and discussed.

43 PARTICLE ACCELERATORS↗

DOE OSTI2018

Microwave Impedance Matching of Feed Waveguides to the Disk-Loaded Accelerator Structure Operating in the (2*Pi)/3 Mode

Explore the source record for details and available documents.

Westbrook, E.↗

DOE OSTI2018

Apparatus and method for fusion of compute and switching functions of exascale system into a single component by using configurable network-on-chip fabric with distributed dual mode input-output ports and programmable network interfaces

Described is an apparatus which comprises: a Network-On-Chip fabric using crossbar switches, having distributed ingress and egress ports; and a dual-mode network interface coupled to at least one crossbar switch, the dual-mode network interface is to include: a dual-mode circuitry; a controller operable to: configure the dual-mode circuitry to transmit and receive differential signals via the egress and ingress ports, respectively, and configure the dual-mode circuitry to transmit and receive signal-ended signals via the egress and ingress ports, respectively.

97 MATHEMATICS AND COMPUTING↗

DOE OSTI2016

Low-Mass Dark Matter Search Results and Radiogenic Backgrounds for the Cryogenic Dark Matter Search

An ever-increasing amount of evidence suggests that approximately one quarter of the energy in the universe is composed of some non-luminous, and hitherto unknown, “dark matter”. Physicists from numerous sub-fields have been working on and trying to solve the dark matter problem for decades. The common solution is the existence of some new type of elementary particle with particular focus on weakly interacting massive particles (WIMPs). One avenue of dark matter research is to create an extremely sensitive particle detector with the goal of directly observing the interaction of WIMPs with standard matter. The Cryogenic Dark Matter Search (CDMS) project operated at the Soudan Underground Laboratory from 2003–2015, under the CDMS II and SuperCDMS Soudan experiments, with this goal of directly detecting dark matter. The next installation, SuperCDMS SNOLAB, is planned for near-future operation. The reason the dark-matter particle has not yet been observed in traditional particle physics experiments is that it must have very small cross sections, thus making such interactions extremely rare. In order to identify these rare events in the presence of a background of known particles and interactions, direct detection experiments employ various types and amounts of shielding to prevent known backgrounds from reaching the instrumented detector(s). CDMS utilized various gamma and neutron shielding to such an effect that the shielding, and other experimental components, themselves were sources of background. These radiogenic backgrounds must be understood to have confidence in any WIMP-search result. For this dissertation, radiogenic background studies and estimates were performed for various analyses covering CDMS II, SuperCDMS Soudan, and SuperCDMS SNOLAB. Lower-mass dark matter t c2 inent in the past few years. The CDMS detectors can be operated in an alternative, higher-biased, mode v to decrease their energy thresholds and correspondingly increase their sensitivity to low-mass WIMPs. This is the CDMS low ionization threshold experiment (CDMSlite), which has pushed the frontier at lower WIMP masses. This dissertation describes the second run of CDMSlite at Soudan: its hardware, operations, analysis, and results. The results include new WIMP mass-cross section upper limits on the spin-independent and spin-dependent WIMP-nucleon interactions. Thanks to the lower background and threshold in this run compared to the first CDMSlite run, these limits are the most sensitive in the world below WIMP masses of ⇠4 GeV/c2. This demonstrates also the great promise and utility of the high-voltage operating mode in the SuperCDMS SNOLAB experiment.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

DOE OSTI2019

Energy recovery in capacitive deionization systems with inverted operation characteristics

Capacitive deionization (CDI) operated under inverted mode involves electronic charging and discharge steps with corresponding ion concentration and desalting coupled with simultaneous energy storage. In this work, an energy recovery system derived from a Cuk dc–dc converter is explored to transfer the energy stored from one inverted capacitive deionization (i-CDI) cell during the electronic discharge step to another during the charge step, decreasing the overall energy requirement for capacitive water desalination. The i-CDI cell, a subset of CDI architecture operated in an inverted mode, is improved by incorporating ion-selective membranes to allow inverted membrane capacitive deionization (i-MCDI), leading to enhanced charge storage achieved with reduced energy input. For example, in comparison to i-CDI that requires ~12 J g -1 of energy input, the i-MCDI cell requires only 8 J g -1 . By incorporating the recovery system, the energy penalty can be reduced to only require ~8 and 4 J g -1 for i-CDI and i-MCDI cells, respectively. Improvement in energy recovery was shown to be achieved by reducing charge leakage, with the i-MCDI cell showing up to 3 times the leakage resistance of the i-CDI cell.

54 ENVIRONMENTAL SCIENCES↗

DOE OSTI2025

JGI-Trichoderma v1.0

There is a series of Python and bash scripts to parse genomics datasets used to evaluate the coevolution of gene families and the feature importance of gene families using an SVM classifier. - Cover analysis: takes a list of single-copy genes in a set of genomes, aligns and builds the gene trees to determine if two gene families have a signature of covariation with one another. It parses the files to run phykit cover script described here: https://jlsteenwyk.com/PhyKIT/usage/index.html - SVM-classifier: This Python script is an SVM-based genomic classifier designed for biological data analysis. It combines machine learning with feature selection to identify important genomic markers and classify biological samples. Core Functionality: The script uses Support Vector Machines from scikit-learn to classify genomic data, incorporating SelectKBest for automated feature selection and leave-one-out cross-validation for performance assessment. It operates in multiple modes: feature ranking, optimal combination discovery, and sample prediction. Primary Applications: Genomic sample classification and biomarker discovery Feature importance analysis in high-dimensional biological datasets Prediction of sample categories based on genomic profiles Research applications requiring robust classification of biological data Key Advantages: High-dimensional handling: SVMs excel with genomic data's typical high feature-to-sample ratios Integrated feature selection: Reduces noise and computational overhead while identifying key markers Probability estimation: Provides confidence scores essential for biological interpretation Validation robustness: Leave-one-out cross-validation ensures reliable performance metrics Operational flexibility: Multiple analysis modes support different research phases from exploration to prediction

Stecca Steindorff, Andrei [Lawrence Berkeley Natio↗

DOE OSTI2023

Compact Multicell Superconducting Crab Cavity for ILC

We propose a novel design of a crab cavity (CC) for the ILC project with low parasitic High Order Modes (HOM) losses and preserving the beam emittance, which is critical for operation with high beam current intensity. Multiple electrodes immersed in the hollow waveguide form a trapped-mode resonator. The transverse components of the electromagnetic field of the trapped dipole mode induce a transverse kick and efficiently deflect charged particles passing through the cavity. We present a scalable design of a superconducting Quasi-waveguide Multicell Resonator (QMiR) seamlessly connected with a beam vacuum chamber. The cavity is completely open at both ends, which significantly reduces the maximum loaded quality factor of the higher order modes (HOM), avoids complex HOM couplers, and thus simplifies the mechanical design of the cavity. The same port is used to feed RF power to the operating mode and to extract the same order modes (SOM). Finally, we estimate the expected cryogenic losses, HOM impedance limits, RF input power required, and frequency tuning for a QMiR cavity designed to operate at 2.6 GHz.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

DOE OSTI2021

A Robust Yule-Walker Method for Online Monitoring of Power System Electromechanical Modes of Oscillation

Reliable power system operation requires that system operators maintain a satisfactory small-signal stability margin at all times. Mode meters allow system operators to continuously monitor the stability margin by analyzing synchrophasor measurements. Experience with mode meters at the Bonneville Power Administration (BPA) has revealed that mode meters sometimes suffer severe bias following transient disturbances. In this paper, a robust version of the Yule-Walker mode meter algorithm is proposed to mitigate this bias. The robust capability is introduced by modifying the estimator of the autocovariance sequence (ACS) on which the algorithm depends. Tests with field-measured data demonstrate that the robust Yule-Walker (RYW) algorithm significantly outperforms its conventional counterpart and is better able to provide system operators with accurate information about the system's stability margin.

Follum, James D.↗

DOE OSTI2019

The Microgrid Performance Reliability Model (MPRM) v. 1.50 Beta

The MPRM is a simulation code that is used to statistically quantify the performance and reliability of a microgrid operating in islanded mode. Performance can be expressed in terms of fuel efficiency, renewable penetration, and other operational characteristics of the grid. Reliability can be expressed in terms of frequency and magnitude of load loss on a tier-by-tier, bus-by-bus basis or on an

Eddy, John↗

DOE OSTI2016

Fermilab Recycler Collimation System Design

To provide 700 kW proton beams for neutrino production in the NuMI facility, we employ slip stacking in the Recycler with transfer to the Main Injector for recapture and acceleration. Slip stacking with 12 Booster batches per 1.33 sec cycle of the Main Injector has been implemented and briefly tested while extensive operation with 8 batches and 10 batches per MI cycle has been demonstrated. Operation in this mode since 2013 shows that loss localization is an essential component for long term operation. Beam loss in the Recycler will be localized in a collimation region with design capability for absorbing up to 2 kW of lost protons in a pair of 20-Ton collimators (absorbers). This system will employ a two stage collimation with a thin molybdenum scattering foil to define the bottom edge of both the injected and decelerated-for-slipping beams. Optimization and engineering design of the collimator components and radiation shielding are based on comprehensive MARS15 simulations predicting high collimation efficiency as well as tolerable levels of prompt and residual radiation. The system installation during the Fermilab 2016 facility shutdown will permit commissioning in the subsequent operating period.

43 PARTICLE ACCELERATORS↗

DOE OSTI2016

Comparison of RCCI Operation with and without EGR over the Full Operating Map ofa Heavy-Duty Diesel Engine

Dual-fuel combustion using port-injection of low reactivity fuel combined with direct injection of a higher reactivity fuel, otherwise known as Reactivity Controlled Compression Ignition (RCCI), has been shown as a method to achieve high efficiency combustion with moderate peak pressure rise rates, low engine-out soot and NOx emissions. A key requirement for extending to high-load operation is reduce the reactivity of the premixed charge prior to the diesel injection. One way to accomplish this is to use a very low reactivity fuel such as natural gas. In this work, experimental testing was conducted on a 13L multi-cylinder heavy-duty diesel engine modified to operate using RCCI combustion with port injection of natural gas and direct injection of diesel fuel. Natural gas/diesel RCCI engine operation is compared over the EPA Heavy-Duty 13 mode supplemental emissions test with and without EGR. Emissions and efficiency metrics were examined over the entire engine map for both operating modes. It was found that the use of EGR lowered combustion noise to less than 97 dBa and lowered the cycle averaged NOx emissions by 48%, with only a slight increase in soot and 0.5 point decrease in brake thermal efficiency. Thus, operation with EGR offered the lowest total fluid consumption when considering the use of a selective catalytic reduction system for NOx aftertreatment.

Hanson, Reed↗

DOE OSTI2017

Grassmann phase space methods for fermions. II. Field theory

In both quantum optics and cold atom physics, the behaviour of bosonic photons and atoms is often treated using phase space methods, where mode annihilation and creation operators are represented by c-number phase space variables, with the density operator equivalent to a distribution function of these variables. The anti-commutation rules for fermion annihilation, creation operators suggests the possibility of using anti-commuting Grassmann variables to represent these operators. However, in spite of the seminal work by Cahill and Glauber and a few applications, the use of Grassmann phase space methods in quantum-atom optics to treat fermionic systems is rather rare, though fermion coherent states using Grassmann variables are widely used in particle physics. This paper presents a phase space theory for fermion systems based on distribution functionals, which replace the density operator and involve Grassmann fields representing anti-commuting fermion field annihilation, creation operators. It is an extension of a previous phase space theory paper for fermions (Paper I) based on separate modes, in which the density operator is replaced by a distribution function depending on Grassmann phase space variables which represent the mode annihilation and creation operators. This further development of the theory is important for the situation when large numbers of fermions are involved, resulting in too many modes to treat separately. Here Grassmann fields, distribution functionals, functional Fokker–Planck equations and Ito stochastic field equations are involved. Typical applications to a trapped Fermi gas of interacting spin 1/2 fermionic atoms and to multi-component Fermi gases with non-zero range interactions are presented, showing that the Ito stochastic field equations are local in these cases. For the spin 1/2 case we also show how simple solutions can be obtained both for the untrapped case and for an optical lattice trapping potential.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗

DOE OSTI2020

An experimental study of the behavior of a high efficiency residential heat pump in cooling mode with common installation faults imposed

Faults are believed to be common in split system air-conditioner and heat pump systems, due to operating degradation or installation problems. Common faults include improper refrigerant charge, reduced evaporator airflow, liquid line restrictions, and the presence of non-condensable gas. Laboratory tests were used to quantify fault impacts on performance of a heat pump system, and impacts on indicator variables such as refrigerant temperatures and pressures. This paper describes a large set of laboratory tests implemented on a high efficiency heat pump operating in cooling mode. This system uses R-410A refrigerant and has a rotary compressor, TXV, two accumulators, and a compensator. A small number of previous experimental studies have been done previously to study the effects of some operating faults, but none has examined a modern system with these components. The tests were conducted with a range of fault intensities and driving conditions. The results are compared to previous researchers’ experimental results. The system’s performance was found to be quite robust in the presence of faults. The TXV, accumulators, and compensator significantly reduce sensitivity to refrigerant charge and liquid line restriction faults, and other faults to a lesser extent.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

DOE OSTI2021

Discrete variable valve lift engine systems and methods

A method of providing a rocker arm set for a valvetrain includes providing a first rocker arm configured as a switching rocker arm for a first intake valve, and providing a second rocker arm configured as a fixed rocker arm for a second intake valve, the second rocker arm operating in a normal Otto cycle mode. The first rocker arm operates in a late intake valve closing (LIVC) mode where the first rocker arm is configured to close the first intake valve later than the second intake valve.

McCarthy, Jr., James E.↗