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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 829 records · Page 46
All sourcesNASA NTRSDOE OSTI
DOE OSTI2012

Addition of Bevacizumab to Standard Radiation Therapy and Daily Temozolomide Is Associated With Minimal Toxicity in Newly Diagnosed Glioblastoma Multiforme

Purpose: To determine the safety of the addition of bevacizumab to standard radiation therapy and daily temozolomide for newly diagnosed glioblastoma multiforme (GBM). Methods and Materials: A total of 125 patients with newly diagnosed GBM were enrolled in the study, and received standard radiation therapy and daily temozolomide. All patients underwent a craniotomy and were at least 2 weeks postoperative. Radiation therapy was administered in 1.8-Gy fractions, with the clinical target volume for the primary course treated to a dose of 45 to 50.4 Gy, followed by a boost of 9 to 14.4 Gy, to a total dose of 59.4 Gy. Patients received temozolomide at 75 mg/m{sup 2} daily throughout the course of radiation therapy. Bevacizumab was given at 10 mg/kg intravenously every 14 days, beginning a minimum of 4 weeks postoperatively. Results: Of the 125 patients, 120 (96%) completed the protocol-specified radiation therapy. Five patients had to stop the protocol therapy, 2 patients with pulmonary emboli, and 1 patient each with a Grade 2 central nervous system hemorrhage, Grade 4 pancytopenia, and wound dehiscence requiring surgical intervention. All 5 patients ultimately finished the radiation therapy. After radiation therapy, 3 patients had progressive disease, 2 had severe fatigue and decreased performance status, 1 patient had a colonic perforation, and 1 had a rectal fissure; these 7 patients therefore did not proceed with the protocol-specified adjuvant temozolomide, bevacizumab, and irinotecan. However, 113 patients (90%) were able to continue on study. Conclusions: The addition of bevacizumab to standard radiation therapy and daily temozolomide was found to be associated with minimal toxicity in patients newly diagnosed with GBM.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2022

Multi-lab study on the pure-gas permeation of commercial polysulfone (PSf) membranes: Measurement standards and best practices

Gas-separation membranes are a critical industrial component for a low-carbon and energy-efficient future. As a result, many researchers have been testing membrane materials over the past several decades. Unfortunately, almost all membrane-based testing systems are home-built, and there are no widely accepted material standards or testing protocols in the literature, making it challenging to accurately compare experimental results. Further, in this multi-lab study, ten independent laboratories collected high-pressure pure-gas permeation data for H 2 , O 2 , CH 4 , and N 2 in commercial polysulfone (PSf) films. Equipment information, testing procedures, and permeation data from all labs were collected to provide (1) accepted H 2 , O 2 , CH 4 , and N 2 permeability values at 35°C in PSf as a reference standard, (2) statistical analysis of lab-to-lab uncertainties in evaluating permeability, and (3) a list of best practices for sample preparation, equipment set-up, and permeation testing using constant-volume variable-pressure apparatuses. Results summarized in this work provide a reference standard and recommended testing protocols for pure-gas testing of membrane materials.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2023

A standard capsule design for structural material testing in the Advanced Test Reactor

Nuclear materials testing is commonly completed in various material test and research reactors throughout the world, including the Advanced Test Reactor (ATR), but the current capsule design, analysis, and fabrication process can take years to complete. To decrease the costs and time associated with materials testing, a standard capsule has been designed which houses various specimen geometries and allows irradiation in virtually any ATR test position. The standard capsule features locking end caps which connect and lock together to form the capsule stack, eliminating the need for a basket and maximizing the quantity of specimens which are contained within the capsule. A customizable internal gas gap provides thermal resistance between the specimens and reactor coolant, making specimen temperatures from approximately 370 to 1000 K achievable. The flexibility of the capsule design allows experimenters to choose irradiation positions based off desired neutron flux, with typical fluences per cycle ranging from 8.8x10 19 to 2.3x10 21 n/cm 2 , depending on experiment position. Here this paper presents and discusses the standard capsule design and analysis.

36 MATERIALS SCIENCE↗
DOE OSTI2026

Comparison of the performance of TLD, OSL and RPL personal dosimetry systems to the American National Standard Institute (ANSI) test categories

The Laboratory Accreditation Program (LAP) tests the capability and performance of the United States Department of Energy's (USDOE) facilities to accurately measure and quantify the whole-body and extremity radiation equivalent doses to the occupational workers. The dosimetry methods used in personal dosimetry can be Thermoluminescence (TL), Optically Stimulated Luminescence (OSL) and Radiophotoluminescence (RPL), among other techniques available. Currently, the TL (LiF:Mg,Ti) and OSL (Al 2 O 3 :C) dosimetry systems are DOELAP-accredited for occupational dose measurements and regulatory reporting. In this study, the performance of a beryllium oxide (BeO) OSL dosimetry system and of a silver-doped phosphate glass RPL dosimetry system is compared against the performance of an accredited LiF:Mg,Ti TL dosimetry system. The bias and standard deviation in each of the performance test categories are compared between these three systems for exposures to photons, beta, and mixed radiation fields with the criteria established by the American National Standard Institute (ANSI) and Health Physics Society (HPS) N13.11-2022 standard. The practical implementation of the dosimetry program and its equivalency to the occupational personal equivalent dose H p (0.07) and H p (10) measurements were evaluated. The TL, OSL and RPL dosimetry systems passed the ANSI performance test criteria for H p (0.07) and H p (10) occupational dose measurements and met the DOELAP accreditation requirements.

61 RADIATION PROTECTION AND DOSIMETRY↗
DOE OSTI2023

A review of regulatory standard test methods for residential wood heaters and recommendations for their advancement

In many regions, residential wood heaters are a leading source of harmful air pollution but only satisfy a small portion of local heating demands. In response, standardized laboratory test methods have been developed to characterize and limit wood heater emissions. While these test methods are a key tool for advancing both wood heater technology and environmental regulations, many of the experimental procedures are outdated and provide few actionable insights for improving heater performance. Furthermore, these test methods vary widely around the world and may not adequately capture the performance of wood heaters operating in residences. This study presents a comprehensive review of standardized wood heater test methods to identify fundamental experimental objectives and regulated performance metrics. Using the results of this review, recommendations are provided to make the test methods more accessible and representative of residential performance, while generating actionable data to motivate heater design improvements. This study elucidates the current state of standard test methods, and the developments needed to advance clean wood heater technologies and public policies.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2010

Nuclear Physics and the New Standard Model

Nuclear physics studies of fundamental symmetries and neutrino properties have played a vital role in the development and confirmation of the Standard Model of fundamental interactions. With the advent of the CERN Large Hadron Collider, experiments at the high energy frontier promise exciting discoveries about the larger framework in which the Standard Model lies. In this talk, I discuss the complementary opportunities for probing the 'new Standard Model' with nuclear physics experiments at the low-energy high precision frontier.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2014

A programmable quantum current standard from the Josephson and the quantum Hall effects

We propose a way to realize a programmable quantum current standard (PQCS) from the Josephson voltage standard and the quantum Hall resistance standard (QHR) exploiting the multiple connection technique provided by the quantum Hall effect (QHE) and the exactness of the cryogenic current comparator. The PQCS could lead to breakthroughs in electrical metrology like the realization of a programmable quantum current source, a quantum ampere-meter, and a simplified closure of the quantum metrological triangle. Moreover, very accurate universality tests of the QHE could be performed by comparing PQCS based on different QHRs.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2017

Energy Efficiency and Emissions Intensity Standards

We investigate the role of energy efficiency in rate-based emissions intensity standards, a particularly policy-relevant consideration given that the Environmental Protection Agency's Clean Power Plan allows crediting of electricity savings as a means of complying with state-specific emissions standards. We show that with perfectly inelastic energy services demand, crediting efficiency measures can recover the first-best allocation. However, when demand for energy services exhibits some elasticity, crediting energy efficiency can no longer recover first-best. While crediting removes the relative distortion between energy generation and energy efficiency, it distorts the absolute level of energy services. Building on these results, we derive the conditions determining the second-best intensity standard and crediting rule. Simulations calibrated to the electricity sector in Texas find that while some form of crediting is generally welfare-improving, the proposed one-for-one crediting of energy savings is unlikely to achieve efficient outcomes.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2011

Higgs chaotic inflation in standard model and NMSSM

We construct a chaotic inflation model in which the Higgs fields play the role of the inflaton in the standard model as well as in the singlet extension of the supersymmetric standard model. The key idea is to allow a non-canonical kinetic term for the Higgs field. The model is a realization of the recently proposed running kinetic inflation, in which the coefficient of the kinetic term grows as the inflaton field. The inflaton potential depends on the structure of the Higgs kinetic term. In the simplest cases, the inflaton potential is proportional to φ{sup 2} and φ{sup 2/3} in the standard model and NMSSM, respectively.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2013

Curvaton decay by resonant production of the Standard Model higgs

We investigate in detail a model where the curvaton is coupled to the Standard Model higgs. Parametric resonance might be expected to cause a fast decay of the curvaton, so that it would not have time to build up the curvature perturbation. However, we show that this is not the case, and that the resonant decay of the curvaton may be delayed even down to electroweak symmetry breaking. This delay is due to the coupling of the higgs to the thermal background, which is formed by the Standard Model degrees of freedom created from the inflaton decay. We establish the occurrence of the delay by considering the curvaton evolution and the structure of the higgs resonances. We then provide analytical expressions for the delay time, and for the subsequent resonant production of the higgs, which ultimately leads to the curvaton effective decay width. Contrary to expectations, it is possible to obtain the observed curvature perturbation for values of the curvaton-higgs coupling as large as 10{sup −1}. Our calculations also apply in the general case of curvaton decay into any non Standard Model species coupled to the thermal background.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2015

Bounce inflation cosmology with Standard Model Higgs boson

It is of great interest to connect cosmology in the early universe to the Standard Model of particle physics. In this paper, we try to construct a bounce inflation model with the standard model Higgs boson, where the one loop correction is taken into account in the effective potential of Higgs field. In this model, a Galileon term has been introduced to eliminate the ghost mode when bounce happens. Moreover, due to the fact that the Fermion loop correction can make part of the Higgs potential negative, one naturally obtains a large equation of state(EoS) parameter in the contracting phase, which can eliminate the anisotropy problem. After the bounce, the model can drive the universe into the standard higgs inflation phase, which can generate nearly scale-invariant power spectrum.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2011

Searches for Physics beyond the Standard Model

The Thomas Jefferson National Accelerator Laboratory has the demonstrated ability to test the fundamental symmetries of nature to very great precision and thereby probe for new physics beyond the Standard Model (SM). In the following objectives and descriptions will be given of three Jefferson Laboratory (JLab) experiments: Qweak, MOLLER, and PVDIS. The Qweak experiment is to measure the weak charge of the proton (via the vector coupling of the Z0 boson to the proton). The MOLLER experiment is to measure the weak charge of the electron. The PV-DIS experiment will measure combinations of vector couplings and axial-vector couplings to the quarks of the nucleons. These three experiments follow from the advances made in precision parity-violating electron scattering measurements at the CEBAF of JLab. The Standard Model makes accurate predictions of the 'running' of the electroweak mixing angle or sin2(θw) from the Z0 pole down to low energies and therefore of the weak charges of the proton and electron. The Qweak experiment will make the first precision determination of the weak charge of the proton, Qpw = 1 – 4 sin2 (θw), from a measurement of the parity-violating asymmetry in the elastic scattering of longitudinally polarized electrons from the protons in a liquid hydrogen target at very low momentum transfer. The projected result will determine the proton's weak charge with a 4.1% total error and consequently sin2 (θw) with a 0.3% error. The Qweak experiment is at present three months into its commissioning run. The MOLLER experiment is to measure the parity-violating asymmetry in the scattering of 11 GeV longitudinally polarized electrons from the atomic electrons in a liquid hydrogen target. The longitudinal analyzing power Az is predicted to be 35.6 ppb at the kinematics of the experiment and is to be determined with a precision of 0.73 ppb, which would make the MOLLER experiment the most precise parity-violation experiment ever undertaken. The result would yield a measurement of the weak charge of the electron to 2.3% at an average Q2 value of 0.0056 (GeV/c)2 and in turn a determination of the electroweak mixing angle sin2(θw) with an uncertainty of ±0.00026 (stat) ±0.00013 (syst), comparable to the accuracy of the two best determinations at the Z0 pole. The PVDIS experiment is to measure the parity-violating asymmetry in deep inelastic scattering of longitudinally polarized electrons from an unpolarized deuterium target. The longitudinal analyzing power can be expressed in terms of the quark distribution functions of the deuterium target and the couplings C1q (axial electron x vector quark) and C2q (vector electron x axial quark), which in the Standard Model can be expressed in terms of sin2(θw).

08 HYDROGEN↗
DOE OSTI2017

The metagenomic data life-cycle: standards and best practices

Metagenomics data analyses from independent studies can only be compared if the analysis workflows are described in a harmonised way. In this overview, we have mapped the landscape of data standards available for the description of essential steps in metagenomics: (1) material sampling, (2) material sequencing (3) data analysis and (4) data archiving & publishing. Taking examples from marine research, we summarise essential variables used to describe material sampling processes and sequencing procedures in a metagenomics experiment. These aspects of metagenomics dataset generation have been to some extent addressed by the scientific community but greater awareness and adoption is still needed. We emphasise the lack of standards relating to reporting how metagenomics datasets are analysed and how the metagenomics data analysis outputs should be archived and published. We propose best practice as a foundation for a community standard to enable reproducibility and better sharing of metagenomics datasets, leading ultimately to greater metagenomics data reuse and repurposing.

96 KNOWLEDGE MANAGEMENT AND PRESERVATION↗
DOE OSTI2010

Prospects for observing the standard model Higgs boson decaying into bb final states produced in weak boson fusion with an associated photon at the LHC

One of the primary goals of the Large Hadron Collider is to understand the electroweak symmetry breaking mechanism. In the standard model, electroweak symmetry breaking is described by the Higgs mechanism which includes a scalar Higgs boson. Electroweak measurements constrain the standard model Higgs boson mass to be in the 114.4 to 157 GeV/c{sup 2} range. For m{sub h}<135 GeV/c{sup 2}, the Higgs predominantly decays into two b-quarks. As such, we investigate the prospect of observing the standard model Higgs decaying to bb produced in weak-boson-fusion with an associated central photon. An isolated, high p{sub T}, central photon trigger is expected to be available at the ATLAS and CMS experiments. In this study, we investigated the effects originating from showering, hadronization, the underlying event model, and jet performance including b-jet calibration on the sensitivity of this channel. We found that the choice of Monte Carlo simulation and its tune has a large effect on the efficacy of the central jet veto and consequently the signal significance. A signal significance of 1.6{sub -0.3}{sup +0.5} can be achieved for m{sub h}=115 GeV/c{sup 2} with 100 fb{sup -1} of integrated luminosity which correspond to 1 yr at design luminosity at 14 TeV pp collisions.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2010

Pseudoscalar boson and standard model-like Higgs boson productions at the LHC in the simplest little Higgs model

In the framework of the simplest little Higgs model, we perform a comprehensive study for the pair productions of the pseudoscalar boson {eta} and standard model-like Higgs boson h at LHC, namely gg(bb){yields}{eta}{eta}, gg(qq){yields}{eta}h, and gg(bb){yields}hh. These production processes provide a way to probe the couplings between Higgs bosons. We find that the cross section of gg{yields}{eta}{eta} always dominates over that of bb{yields}{eta}{eta}. When the Higgs boson h which mediates these two processes is on-shell, their cross sections can reach several thousand fb and several hundred fb, respectively. When the intermediate state h is off-shell, those two cross sections are reduced by 2 orders of magnitude, respectively. The cross sections of gg{yields}{eta}h and qq{yields}{eta}h are about in the same order of magnitude, which can reach O(10{sup 2} fb) for a light {eta} boson. Besides, compared with the standard model prediction, the cross section of a pair of standard model-like Higgs bosons production at LHC can be enhanced sizably. Finally, we briefly discuss the observable signatures of {eta}{eta}, {eta}h, and hh at the LHC.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2010

Exact one-loop evolution invariants in the standard model

Guided by considerations of flavor symmetry, we construct a set of exact standard model renormalization group evolution invariants which link quark masses and mixing parameters. We examine their phenomenological implications and infer a simple combination of Yukawa coupling matrices which plays a unique role in the standard model, suggesting a possible new insight into the observed spectrum of quark masses. Our evolution invariants are readily generalized to the leptons in the case of Dirac neutrinos, but do not appear to be relevant for either quarks or leptons in the minimal supersymmetric standard model.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2011

Search for a Standard Model Higgs Boson in the H to ZZ to l(+)l(-)v(v)over-bar Decay Channel with the ATLAS Detector

A search for a heavy standard model Higgs boson decaying via H {yields} ZZ {yields} {ell}{sup +}{ell}{sup -} {nu}{bar {nu}}, where {ell} = e, {mu}, is presented. It is based on proton-proton collision data at {radical}s = 7 TeV, collected by the ATLAS experiment at the LHC in the first half of 2011 and corresponding to an integrated luminosity of 1.04 fb{sup -1}. The data are compared to the expected standard model backgrounds. The data and the background expectations are found to be in agreement and upper limits are placed on the Higgs boson production cross section over the entire mass window considered; in particular, the production of a standard model Higgs boson is excluded in the region 340 < m{sub H} < 450 GeV at the 95% confidence level.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2015

Comparative Study of Standards for Grid-Connected Wind Power Plant in China and the U.S.

The rapid deployment of wind power has made grid integration and operational issues focal points in industry discussions and research. Compliance with grid connection standards for wind power plants (WPP) is crucial to ensuring the safe and stable operation of the electric power grid. The standards for grid-connected WPPs in China and the United States are compared in this paper to facilitate further improvements to the standards and enhance the development of wind power equipment. Detailed analyses in power quality, low-voltage ride-through capability, active power control, reactive power control, voltage control, and wind power forecasting are provided to enhance the understanding of grid codes in the two largest markets of wind power.

17 WIND ENERGY↗