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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 253 records · Page 14
All sourcesNASA NTRSDOE OSTI
DOE OSTI2014

Sci—Fri PM: Topics — 02: Evaluation of Dosimetric Variations in Partial Breast Seed Implant (PBSI) due to Patient Arm Position (Up vs. Down)

The planning for PBSI is done with the patient's ipsilateral arm raised, however, anatomical changes and variations are unavoidable as the patient resumes her daily activities, potentially resulting in significant deviations in implant geometry from the treatment plan. This study aims to quantify the impact of the ipsilateral arm position on the geometry and dosimetry of the implant at eight weeks, evaluated on post-plans using the MIM Symphony™ software (MIM Software, Cleveland, OH). The average dose metrics for the three patients treated at the TBCC thus far using rigid fusion and contour transfer for the arms up position were 76% for the CTV V100, 61% for the PTV V100, and 37% for the PTV V200; and for the arms down position 81% for the CTV V100, 64% for the PTV V100, and 42% for the PTV V200. Qualitative analysis of the post-implant CT for one of the three patients showed poor agreement between the seroma contour transferred from the pre-implant CT and the seroma visible on the post-implant CT. To obtain a clinically accurate plan for that patient, contour modifications were used, yielding improved dose metric averages for the arms-up position for all three patients of 87% for the CTV V100, 68% for the PTV V100, and 39% for the PTV V200. Overall, the data available shows that dosimetric parameters increase with the patient's arm down, both in terms of coverage and in terms of the hot spot, and accrual of more patients may confirm this in a larger population.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2014

Sci—Fri PM: Topics — 03: The Global Task Force on Radiotherapy for Cancer Control: Core Investments

The Union for International Cancer Control (UICC) is a membership-based, non-governmental organization with a mandate to “…to unite the cancer community to reduce the global cancer burden, to promote greater equity, and to integrate cancer control into the world health and development agenda.” COMP is an associate member of the UICC. It is well recognized by the UICC that there are major gaps between high, and low and middle income countries, in terms of access to cancer services including access to radiation therapy. In this context, the UICC has developed a Global Task Force on Radiotherapy for Cancer Control with a charge to answer a single question: “What does it cost to close the gap between what exists today and reasonable access to radiotherapy globally?” The Task Force consists of leaders internationally recognized for their radiation treatment related expertise (radiation oncologists, medical physicists, radiation therapists) as well as those with global health and economics specialization. The Task Force has developed three working groups: (1) to look at the global burden of cancer; (2) to look at the infrastructure requirements (facilities, equipment, personnel); and (3) to consider outcomes in terms of numbers of lives saved and palliated patients. A report is due at the World Cancer Congress in December 2014. This presentation reviews the infrastructure considerations under analysis by the second work group. The infrastructure parameters being addressed include capital costs of buildings and equipment and operating costs, which include human resources, equipment servicing and quality control, and general overhead.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2014

Sci—Fri PM: Topics — 04: What if bystander effects influence cell kill within a target volume? Potential consequences of dose heterogeneity on TCP and EUD on intermediate risk prostate patients

In vitro evidence has suggested that radiation induced bystander effects may enhance non-local cell killing which may influence radiotherapy treatment planning paradigms. This work applies a bystander effect model, which has been derived from published in vitro data, to calculate equivalent uniform dose (EUD) and tumour control probability (TCP) and compare them with predictions from standard linear quadratic (LQ) models that assume a response due only to local absorbed dose. Comparisons between the models were made under increasing dose heterogeneity scenarios. Dose throughout the CTV was modeled with normal distributions, where the degree of heterogeneity was then dictated by changing the standard deviation (SD). The broad assumptions applied in the bystander effect model are intended to place an upper limit on the extent of the results in a clinical context. The bystander model suggests a moderate degree of dose heterogeneity yields as good or better outcome compared to a uniform dose in terms of EUD and TCP. Intermediate risk prostate prescriptions of 78 Gy over 39 fractions had maximum EUD and TCP values at SD of around 5Gy. The plots only dropped below the uniform dose values for SD ∼ 10 Gy, almost 13% of the prescribed dose. The bystander model demonstrates the potential to deviate from the common local LQ model predictions as dose heterogeneity through a prostate CTV is varies. The results suggest the potential for allowing some degree of dose heterogeneity within a CTV, although further investigations of the assumptions of the bystander model are warranted.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2014

Sci—Fri PM: Topics — 05: Experience with linac simulation software in a teaching environment

Medical linear accelerator education is usually restricted to use of academic textbooks and supervised access to accelerators. To facilitate the learning process, simulation software was developed to reproduce the effect of medical linear accelerator beam adjustments on resulting clinical photon beams. The purpose of this report is to briefly describe the method of operation of the software as well as the initial experience with it in a teaching environment. To first and higher orders, all components of medical linear accelerators can be described by analytical solutions. When appropriate calibrations are applied, these analytical solutions can accurately simulate the performance of all linear accelerator sub-components. Grouped together, an overall medical linear accelerator model can be constructed. Fifteen expressions in total were coded using MATLAB v 7.14. The program was called SIMAC. The SIMAC program was used in an accelerator technology course offered at our institution; 14 delegates attended the course. The professional breakdown of the participants was: 5 physics residents, 3 accelerator technologists, 4 regulators and 1 physics associate. The course consisted of didactic lectures supported by labs using SIMAC. At the conclusion of the course, eight of thirteen delegates were able to successfully perform advanced beam adjustments after two days of theory and use of the linac simulator program. We suggest that this demonstrates good proficiency in understanding of the accelerator physics, which we hope will translate to a better ability to understand real world beam adjustments on a functioning medical linear accelerator.

07 ISOTOPE AND RADIATION SOURCES↗
DOE OSTI2014

Sci—Fri PM: Topics — 06: The influence of regional dose sensitivity on salivary loss and recovery in the parotid gland

Purpose: The Quantitative Analyses of Normal Tissue Effects in the Clinic (QUANTEC 2010) survey of radiation dose-volume effects on salivary gland function has called for improved understanding of intragland dose sensitivity and the effectiveness of partial sparing in salivary glands. Regional dose susceptibility of sagittally- and coronally-sub-segmented parotid gland has been studied. Specifically, we examine whether individual consideration of sub-segments leads to improved prediction of xerostomia compared with whole parotid mean dose. Methods: Data from 102 patients treated for head-and-neck cancers at the BC Cancer Agency were used in this study. Whole mouth stimulated saliva was collected before (baseline), three months, and one year after cessation of radiotherapy. Organ volumes were contoured using treatment planning CT images and sub-segmented into regional portions. Both non-parametric (local regression) and parametric (mean dose exponential fitting) methods were employed. A bootstrap technique was used for reliability estimation and cross-comparison. Results: Salivary loss is described well using non-parametric and mean dose models. Parametric fits suggest a significant distinction in dose response between medial-lateral and anterior-posterior aspects of the parotid (p<0.01). Least-squares and least-median squares estimates differ significantly (p<0.00001), indicating fits may be skewed by noise or outliers. Salivary recovery exhibits a weakly arched dose response: the highest recovery is seen at intermediate doses. Conclusions: Salivary function loss is strongly dose dependent. In contrast no useful dose dependence was observed for function recovery. Regional dose dependence was observed, but may have resulted from a bias in dose distributions.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2014

Sci—Fri PM: Topics — 07: Monte Carlo Simulation of Primary Dose and PET Isotope Production for the TRIUMF Proton Therapy Facility

Uveal melanoma is a rare and deadly tumour of the eye with primary metastases in the liver resulting in an 8% 2-year survival rate upon detection. Large growths, or those in close proximity to the optic nerve, pose a particular challenge to the commonly employed eye-sparing technique of eye-plaque brachytherapy. In these cases external beam charged particle therapy offers improved odds in avoiding catastrophic side effects such as neuropathy or blindness. Since 1995, the British Columbia Cancer Agency in partnership with the TRIUMF national laboratory have offered proton therapy in the treatment of difficult ocular tumors. Having seen 175 patients, yielding 80% globe preservation and 82% metastasis free survival as of 2010, this modality has proven to be highly effective. Despite this success, there have been few studies into the use of the world's largest cyclotron in patient care. Here we describe first efforts of modeling the TRIUMF dose delivery system using the FLUKA Monte Carlo package. Details on geometry, estimating beam parameters, measurement of primary dose and simulation of PET isotope production are discussed. Proton depth dose in both modulated and pristine beams is successfully simulated to sub-millimeter precision in range (within limits of measurement) and 2% agreement to measurement within in a treatment volume. With the goal of using PET signals for in vivo dosimetry (alignment), a first look at PET isotope depth distribution is presented — comparing favourably to a naive method of approximating simulated PET slice activity in a Lucite phantom.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2014

Sci—Fri PM: Topics — 08: The Role and Benefits of Electromagnetic Needle-Tracking Technologies in Brachytherapy

In modern brachytherapy, application of large doses of ionizing radiation in a limited number of fractions is frequent. Furthermore, as with any surgical procedures, brachytherapy is subject to learning curve effects. In this context, there could be advantages of integrating real-time tracking of needles/catheters to existing protocols given the recent prominent advances in tracking technologies. In this work, we review the use of an electromagnetic tracking system (EMTS) based on the second generation Aurora® Planar Field Generator (Northern Digital Inc) and custom design needles (Philips Healthcare) for brachytherapy applications. The position and orientation information is obtained from 5 degrees of freedom sensors. Basic system performance characterization is performed in well-controlled conditions to establish accuracy and reproducibility as well as potential interference from standard brachytherapy equipment. The results show that sensor locations can be tracked to within 0.04mm (la) when located within 26cm of the generator. Orientation accuracy of the needle remained within ±1° in the same region, but rose quickly at larger distances. The errors on position and orientation strongly dependent the sensor position in the characterization volume (500×500×500mm{sup 3}). The presence of an ultrasound probe was shown to have negligible effects on tracking accuracy. The use of EMTS for automatic catheter/applicator reconstruction was also explored. Reconstruction time was less than 10 sec/channel and tips identification was within 0.69±0.29mm of the reference values. Finally, we demonstrate that hollow needle designs with special EM adaptation also allow for real-time seed drop position estimation. In phantom experiments showed that drop positions were on average within 1.6±0.9mm of the reference position measured from μCT. Altogether, EMTS offer promising benefits in a wide range of brachytherapy applications.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2015

TU-EF-BRD-01: Topics in Quality and Safety Research and Level of Evidence

Research related to quality and safety has been a staple of medical physics academic activities for a long time. From very early on, medical physicists have developed new radiation measurement equipment and analysis techniques, created ever increasingly accurate dose calculation models, and have vastly improved imaging, planning, and delivery techniques. These and other areas of interest have improved the quality and safety of radiotherapy for our patients. With the advent of TG-100, quality and safety is an area that will garner even more research interest in the future. As medical physicists pursue quality and safety research in greater numbers, it is worthwhile to consider what actually constitutes research on quality and safety. For example, should the development of algorithms for real-time EPID-based in-vivo dosimetry be defined as “quality and safety” research? How about the clinical implementation of such as system? Surely the application of failure modes and effects analysis to a clinical process would be considered quality and safety research, but is this type of research that should be included in the medical physics peer-reviewed literature? The answers to such questions are of critical importance to set researchers in a direction that will provide the greatest benefit to our field and the patients we serve. The purpose of this symposium is to consider what constitutes research in the arena of quality and safety and differentiate it from other research directions. The key distinction here is developing the tool itself (e.g. algorithms for EPID dosimetry) vs. studying the impact of the tool with some quantitative metric. Only the latter would I call quality and safety research. Issues of ‘basic’ versus ‘applied’ quality and safety research will be covered as well as how the research results should be structured to provide increasing levels of support that a quality and safety intervention is effective and sustainable. Examples from existing peer-reviewed research will be used to highlight the main points. Historical, medical physicists have leveraged many areas of applied physics, engineering and biology to improve radiotherapy. Research on quality and safety is another area where physicists can have an impact. The key to further progress is to clearly define what constitutes quality and safety research for those interested in doing such research and the reviewers of that research. Learning Objectives: List several tools of quality and safety with references to peer-reviewed literature. Describe effects of mental workload on performance. Outline research in quality and safety indicators and technique analysis. Understand what quality and safety research needs to be going forward. Understand the links between cooperative group trials and quality and safety research.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2015

TU-G-BRB-01: Topic Introduction: Do We Need Clinical Trials in Particle Therapy and How Can Medical Physics Support Them?

Proton therapy, in particular, and ion therapy, just beginning, are becoming an increasing focus of attention in clinical radiation oncology and medical physics. Both modalities have been criticized of lacking convincing evidence from randomized trials proving their efficacy, justifying the higher costs involved in these therapies. This session will provide an overview of the current status of clinical trials in proton therapy, including recent developments in ion therapy. As alluded to in the introductory talk by Dr. Schulte, opinions are diverging widely as to the usefulness and need for clinical trials in particle therapy and the challenge of equipoise. The lectures will highlight some of the challenges that surround clinical trials in particle therapy. One, presented by Dr. Choy from UT Southwestern, is that new technology and even different types of particles such as helium and carbon ions are introduced into this environment, increasing the phase space of clinical variables. The other is the issue of medical physics quality assurance with physical phantoms, presented by Mrs. Taylor from IROC Houston, which is more challenging because 3D and 4D image guidance and active delivery techniques are in relatively early stages of development. The role of digital phantoms in developing clinical treatment planning protocols and as a QA tool will also be highlighted by Dr. Lee from NCI. The symposium will be rounded off by a panel discussion among the Symposium speakers, arguing pro or con the need and readiness for clinical trials in proton and ion therapy. Learning Objectives: To get an update on the current status of clinical trials allowing or mandating proton therapy. Learn about the status of planned clinical trials in the U.S. and worldwide involving ion therapy. Discuss the challenges in the design and QA of clinical trials in particle therapy. Learn about existing and future physical and computational anthropomorphic phantoms for charged particle clinical trial development and support. Research reported in this presentation is supported by the National Cancer Institute of the National; Institutes of Health under Award Number P20CA183640.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2012

Lead Research and Development Activity for DOE's High Temperature, Low Relative Humidity Membrane Program (Topic 2)

The Department of Energy’s High Temperature, Low Relative Humidity Membrane Program was begun in 2006 with the Florida Solar Energy Center (FSEC) as the lead organization. During the first three years of the program, FSEC was tasked with developing non-Nafion® proton exchange membranes with improved conductivity for fuel cells. Additionally, FSEC was responsible for developing protocols for the measurement of in-plane conductivity, providing conductivity measurements for the other funded teams, developing a method for through-plane conductivity and organizing and holding semiannual meetings of the High Temperature Membrane Working Group (HTMWG). The FSEC membrane research focused on the development of supported poly[perfluorosulfonic acid] (PFSA) – Teflon membranes and a hydrocarbon membrane, sulfonated poly(ether ether ketone). The fourth generation of the PFSA membrane (designated FSEC-4) came close to, but did not meet, the Go/No-Go milestone of 0.1 S/cm at 50% relative humidity at 120 °C. In-plane conductivity of membranes provided by the funded teams was measured and reported to the teams and DOE. Late in the third year of the program, DOE used this data and other factors to decide upon the teams to continue in the program. The teams that continued provided promising membranes to FSEC for development of membrane electrode assemblies (MEAs) that could be tested in an operating fuel cell. FSEC worked closely with each team to provide customized support. A logic flow chart was developed and discussed before MEA fabrication or any testing began. Of the five teams supported, by the end of the project, membranes from two of the teams were easily manufactured into MEAs and successfully characterized for performance. One of these teams exceeded performance targets, while the other requires further optimization. An additional team developed a membrane that shows great promise for significantly reducing membrane costs and increasing membrane lifetime.

08 HYDROGEN↗
DOE OSTI2012

Topic 5: Power System Operation and Planning for Enhanced Wind Generation Penetration

This project dealt with the development of a range of educational resources dealing with wind energy and wind energy integration in the electric grid. These resources were developed for a variety of audiences including; a) high school student, b) undergraduate electrical engineering students, c) graduate electrical engineering students, and d) practicing engineers in industry. All the developed material is available publicly and the courses developed are being taught at the two participating universities, Arizona State University and Iowa State University.

17 WIND ENERGY↗
DOE OSTI2014

Gasification Studies: Task 4 Topical Report, Utah Clean Coal Program

A key objective of the Task 4 activities has been to develop simulation tools to support development, troubleshooting and optimization of pressurized entrained-flow coal gasifiers. The overall gasifier models (Subtask 4.1) combine submodels for fluid flow (Subtask 4.2) and heat transfer (Subtask 4.3) with fundamental understanding of the chemical processes (Subtask 4.4) processes that take place as coal particles are converted to synthesis gas and slag. However, it is important to be able to compare predictions from the models against data obtained from actual operating coal gasifiers, and Subtask 4.6 aims to provide an accessible, non-proprietary system, which can be operated over a wide range of conditions to provide well-characterized data for model validation. Highlights of this work include: (1) Verification and validation activities performed with the Arches coal gasification simulation tool on experimental data from the CANMET gasifier (Subtask 4.1). (2) The simulation of multiphase reacting flows with coal particles including detailed gas-phase chemistry calculations using an extension of the one-dimensional turbulence model’s capability (Subtask 4.2). (3) The demonstration and implementation of the Reverse Monte Carlo ray tracing (RMCRT) radiation algorithm in the ARCHES code (Subtask 4.3). (4) Determination of steam and CO 2 gasification kinetics of bituminous coal chars at high temperature and elevated pressure under entrained-flow conditions (Subtask 4.4). In addition, attempts were made to gain insight into the chemical structure differences between young and mature coal soot, but both NMR and TEM characterization efforts were hampered by the highly reacted nature of the soot. (5) The development, operation, and demonstration of in-situ gas phase measurements from the University of Utah’s pilot-scale entrained-flow coal gasifier (EFG) (Subtask 4.6). This subtask aimed at acquiring predictable, consistent performance and characterizing the environment within the gasifier.

01 COAL, LIGNITE, AND PEAT↗
DOE OSTI2014

Additional EIPC Study Analysis: Interim Report on Medium Priority Topics

Between 2010 and 2012 the Eastern Interconnection Planning Collaborative (EIPC) conducted a major long-term resource and transmission study of the Eastern Interconnection (EI). With guidance from a stakeholder steering committee (SSC) that included representatives from the Eastern Interconnection States’ Planning Council (EISPC) among others, the project was conducted in two phases. The first was a 2015–2040 analysis that looked at a broad array of possible future scenarios, while the second focused on a more detailed examination of the grid in 2030. The studies provided a wealth of information on possible future generation, demand, and transmission alternatives. However, at the conclusion there were still unresolved questions and issues. The US Department of Energy, which had sponsored the study, asked Oak Ridge National Laboratory researchers and others who worked on the project to conduct an additional study of the data to provide further insights for stakeholders and the industry. This report documents the second part of that follow-on study [an earlier report (Hadley 2013) covered the first part, and a subsequent report will address the last part].

30 DIRECT ENERGY CONVERSION↗
DOE OSTI2014

Topics in LIFE Target Survival: 11-SI-004 Final Report

The LIFE target design incorporates many considerations to generate the desired fusion gain including the physics design, the cost of manufacturing of the target, the injectability of the target, the aerodynamic flight characteristics of the target, the ability to track and engage the target and to maintain the structural and thermal integrity of the target. This document describes the effort that was made in support of issues of survivability of the target during injection which included issues massmanufactural materials and processes which could be used in the target.

42 ENGINEERING↗
DOE OSTI2015

DOE SBIR 2014 Topic 2.C – Phase I Final Report

Freshwater is a vital resource for human survival as well as a key component of a wide range of industrial and agricultural needs. However, only 0.65% of the world’s water resources are available as freshwater, and the demand on the world’s water reserves continues to increase, with the demand beginning to outpace the supply in many areas. A water-energy nexus is being reached that requires low –cost and –energy solutions for various degrees of treated water. In a 2012 survey, 88% of Americans were concerned about potential water shortages and approximately two-thirds of the world’s population will be suffering a water shortage over the next few years. Seawater and other saline water materials make up around 98% of the available water, representing an almost unlimited supply of water. The energy, cost and maintenance to remove salts and other unwanted compounds is a barrier to widespread implementation of salt-to-freshwater facilities. These facilities most commonly use reverse osmosis (RO) systems. Due to the high required pressures and moving parts these facilities consume much grid energy and require constant maintenance leading to high capital and operational costs. RO also generates highly concentrated brine that is costly to safely return to the ocean. Capacitive desalination (or capacitive deionization [CDI]) has no moving parts (aside from a low pressure pump and valves), operates at low pressure and does not generate brine that is hazardous to marine life. Not only can the capacitive charge/discharge be cycled almost indefinitely but the system uses low energy and capacitive discharge electrical current can be co-generated back to the system. However, CDI has not seen widespread use for large- or small- scale desalination because electrode efficiency limits the extraction rate below what is useful for most applications. Mainstream Engineering Corporation (MEC) has demonstrated an innovative new electrode structure for the high efficiency desalination of brackish water by capacitive deionization. Electrode manufacturing (nanomanufacturing) is a highly scalable and low-cost electrochemical self-assembly method using a templated process that Mainstream has pioneered and leveraged for several energy technologies over the last decade. The primary accomplishment for Phase I is the fabrication and demonstration of CDI electrode structures are: • Demonstrating the linear scalability of templated approach to the fabrication scaling the electrode structure. • Demonstrated the ability to tune the fabrication of the electrode structures to produce electrodes with a highly controllable aligned nanopore diameter and nanopore depth. • Demonstrated the efficient removal of a sodium chloride salt from brackish water with a 60 times improvement in mg-salt removed/g-carbon compared to a commercial system under the same conditions. • Demonstrated good reproducibility and stability of the electrode structure under realistic CDI operating conditions. • Demonstrated charge efficiency as high as 93% with an expected system level energy requirement of 0.7 to 1.5 kWh/m3 of water; significantly lower than the 2.9 to 3.7 kWh/m3 observed for RO systems Based on the performance characteristics of the electrodes, Mainstream was able to propose a modular and scalable capacitive deionization design that can be adapted to a wide range of conditions providing energy efficient desalination of brackish water.

36 MATERIALS SCIENCE↗