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All sourcesNASA NTRSDOE OSTI
DOE OSTI2018

Development of a standard capture efficiency test method for residential kitchen ventilation

Cooking activities are a major source of indoor air pollutants. To control pollutants generated from cooking activities, a range hood is commonly used in residential kitchens. Several building codes require that a range hood be installed in new homes to control pollutants from cooking, and the required airflow rates for range hoods are specified by indoor air quality standards. However, airflow alone does not show how much of the cooking pollutants are exhausted by the range hood. A better metric to evaluate range hood indoor air quality performance is capture efficiency -- the fraction of contaminants emitted during cooking that are exhausted directly to the outside via the range hood. The current article summarizes the development of a range hood capture efficiency test method for use in laboratory testing and equipment rating.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2014

Comparison of the Amanzi Model against Analytical Solutions and the FEHM Model

This file documents Amanzi code verification of flow simulations for three selected cases: (1) an infinite strip aquifer embedded between two other aquifers, (2) a heterogeneous cylinder (or disc in 2D case) embedded in a background aquifer, and (3) uniform aquifers in bounded domains with fixed heads at the upper- and down-stream directions and no-flow at lateral boundaries. The original FORTRAN codes that solve the analytical solutions for cases (1) and (2) were obtained from Greg Ruskauf. Two modifications were made for compilation on Linux systems: (a) The keyword ‘mode’ in OPEN statements was removed because it is not standard, and (b) variables in COMMON blocks were re-arranged to eliminate a warning message (padding of additional 4 bytes). These codes were compiled using the gfortran compiler on the Linux environment. Note that these analytical solutions were derived for two-dimensional problems only, and therefore in numerical simulations, we used three-dimensional domains with unit thickness for comparison.

54 ENVIRONMENTAL SCIENCES↗
NASA NTRS1992

ACSYNT - A standards-based system for parametric, computer aided conceptual design of aircraft

A group of eight US aerospace companies together with several NASA and NAVY centers, led by NASA Ames Systems Analysis Branch, and Virginia Tech's CAD Laboratory agreed, through the assistance of Americal Technology Initiative, in 1990 to form the ACSYNT (Aircraft Synthesis) Institute. The Institute is supported by a Joint Sponsored Research Agreement to continue the research and development in computer aided conceptual design of aircraft initiated by NASA Ames Research Center and Virginia Tech's CAD Laboratory. The result of this collaboration, a feature-based, parametric computer aided aircraft conceptual design code called ACSYNT, is described. The code is based on analysis routines begun at NASA Ames in the early 1970's. ACSYNT's CAD system is based entirely on the ISO standard Programmer's Hierarchical Interactive Graphics System and is graphics-device independent. The code includes a highly interactive graphical user interface, automatically generated Hermite and B-Spline surface models, and shaded image displays. Numerous features to enhance aircraft conceptual design are described.

Jayaram, S.↗
DOE OSTI2019

Core polarization effects: Oscillator strengths, transition probabilities and radiative lifetimes of levels in Bi IV

In this work a systematic analysis of Bi IV atomic properties is presented. Ab initio relativistic Hartree–Fock calculations in an intermediate coupling (IC) formalism and taking into account Core Polarization Effects (CPE) are used. We use for the IC calculations the standard method of least square fitting of experimental energy levels by means of computer codes from Cowan which was modified in order to include CPE. Our calculations have been made from 17 configurations of Bi IV: 5d{sup 10}6s{sup 2}, 5d{sup 10}6p{sup 2}, 5d{sup 10}6sns (n= 7–10) and 5d{sup 10}6snd (n= 6–9) for even parity and 5d{sup 10}6snp (n=6,7), 5d{sup 10}6snf (n=5,6), 5d{sup 9}6s{sup 2}6p and 5d{sup 9}6s{sup 2}nf (n=5,6) for odd parity. Transition probabilities and oscillator strengths for 100 lines and some radiative lifetimes of Bi IV have been calculated. Besides a comparison of our results with the scarce experimental values available in the bibliography are presented. The presence of spectral lines of bismuth in stellar atmospheres has been reported in different stars. This is the motivation by this work can be very interest in astrophysical area. Recently the Bi IV is taking importance because it is considered as the main dopant in the prospective used for the design and synthesis of new scintillators.

74 ATOMIC AND MOLECULAR PHYSICS↗
DOE OSTI2014

Magnetic configuration flexibility of snowflake divertor for HL-2M [Analysis of snowflake divertor configurations for HL-2M]

HL-2M (Li, 2013 [1]) is a tokamak device that is under construction. Based on the magnetic coils design of HL-2M, four kinds of divertor configurations are calculated by CORSICA code (Pearlstein et al., 2001 [2]) with the same main plasma parameters, which are standard divertor, exact snowflake divertor, snowflake-plus divertor and snowflake-minus divertor configurations. The potential properties of these divertors are analyzed and presented in this paper: low poloidal field area around X-point, connection length from outside mid-plane to the primary X-point, target plate design and magnetic field shear. The results show that the snowflake configurations not only can reduce the heat load at divertor target plates, but also may improve the magneto-hydrodynamic stability by stronger magnetic shear at the edge. Furthermore, a new divertor configuration, named “tripod divertor”, is designed by adjusting the positions of the two X-points according to plasma parameters and magnetic coils current of HL-2M.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2020

Application and assessment of deep learning for the generation of potential NMDA receptor antagonists

Uncompetitive antagonists of the N-methyl D-aspartate receptor (NMDAR) have demonstrated therapeutic benefit in the treatment of neurological diseases such as Parkinson's and Alzheimer's, but some also cause dissociative effects that have led to the synthesis of illicit drugs. The ability to generate NMDAR antagonists in silico is therefore desirable for both new medication development and preempting and identifying new designer drugs. Recently, generative deep learning models have been applied to de novo drug design as a means to expand the amount of chemical space that can be explored for potential drug-like compounds. In this study, we assess the application of a generative model to the NMDAR to achieve two primary objectives: (i) the creation and release of a comprehensive library of experimentally validated NMDAR phencyclidine (PCP) site antagonists to assist the drug discovery community and (ii) an analysis of both the advantages conferred by applying such generative artificial intelligence models to drug design and the current limitations of the approach. We apply, and provide source code for, a variety of ligand- and structure-based assessment techniques used in standard drug discovery analyses to the deep learning-generated compounds. Overall, we present twelve candidate antagonists that are not available in existing chemical databases to provide an example of what this type of workflow can achieve, though synthesis and experimental validation of these compounds are still required.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2018

International Neuroscience Initiatives through the Lens of High-Performance Computing

Neuroscience initiatives aim to develop new technologies and tools to measure and manipulate neuronal circuits. In this paper, to deal with the massive amounts of data generated by these tools, the authors envision the co-location of open data repositories in standardized formats together with high-performance computing hardware utilizing open source optimized analysis codes.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2014

MO-H-19A-03: Patient Specific Bolus with 3D Printing Technology for Electron Radiotherapy

Purpose: Bolus is widely used in electron radiotherapy to achieve desired dose distribution. 3D printing technologies provide clinicians with easy access to fabricate patient specific bolus accommodating patient body surface irregularities and tissue inhomogeneity. This study presents the design and the clinical workflow of 3D printed bolus for patient electron therapy in our clinic. Methods: Patient simulation CT images free of bolus were exported from treatment planning system (TPS) to an in-house developed software package. Bolus with known material properties was designed in the software package and then exported back to the TPS as a structure. Dose calculation was carried out to examine the coverage of the target. After satisfying dose distribution was achieved, the bolus structure was transferred in Standard Tessellation Language (STL) file format for the 3D printer to generate the machine codes for printing. Upon receiving printed bolus, a quick quality assurance was performed with patient resimulated with bolus in place to verify the bolus dosimetric property before treatment started. Results: A patient specific bolus for electron radiotherapy was designed and fabricated in Form 1 3D printer with methacrylate photopolymer resin. Satisfying dose distribution was achieved in patient with bolus setup. Treatment was successfully finished for one patient with the 3D printed bolus. Conclusion: The electron bolus fabrication with 3D printing technology was successfully implemented in clinic practice.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2026

poppler-science

The “Poppler-science” software is a fork of the existing open-source Poppler project (https://poppler.freedesktop.org/) for converting PDF files to text. Modifications to the Poppler source code include (a) per-glyph optical character recognition (for correcting the non-standard font glyph remapping that is common in the scientific literature), (b) inference of text markup for commonly used scientific formatting (like superscripts and subscripts), (c) table and figure recognition, and (d) improved ordering of text output for complex scientific manuscripts (e.g., multi-column text, figure and table captions, etc.).

Gans, Jason [Los Alamos National Laboratory]↗
DOE OSTI2014

Experience with OpenMP for MADX-SC

MADX-SC allows the treatment of frozen space charge using beam-beam elements in a thin lattice, i.e. one can take advantage of the standard set-up of MAD-X lattices without the need for specialized codes for the space-charge (SC) evaluation. The idea is to simulate over many turns without the problem of noise as in the PIC SC codes. For the examples under study, like the PS and RHIC, it would be desirable to simulate up to 1 million turns or more. To this end one had to make an effort to optimize the scalar speed and, most importantly, get a speed-up of approximately a factor of 5 using OpenMP.

43 PARTICLE ACCELERATORS↗
DOE OSTI2013

Post-Remediation Radiological Dose Assessment, Painesville Site, Painesville, Ohio

A post-remediation radiological dose assessment was conducted for the Formerly Utilized Sites Remedial Action Program (FUSRAP) Painesville Site by using the measured residual concentrations of the radionuclides of concern following the completion of remedial action. The site’s FUSRAP-related constituents of concern (COCs) are radionuclides associated with past activities conducted by the Manhattan Engineer District (MED) and Atomic Energy Commission (AEC) in support of the Nation’s early atomic energy and weapons program, and include radium-226 (Ra-226), thorium-230 (Th-230), thorium-232 (Th-232), and total uranium (Total U). Remedial actions were conducted at the site in accordance with the Final Record of Decision for the Painesville Site, Painesville, Ohio (ROD) (USACE 2006). In the ROD, the U.S. Army Corps of Engineers (USACE) determined that the U.S. Nuclear Regulatory Commission (NRC) standards for decommissioning of licensed facilities found in Title 10, Part 20.1402 of the Code of Federal Regulations (10 CFR 20.1402) and in the Ohio Administrative Code (OAC) 3701:1-38-22(B) are applicable or relevant and appropriate requirements (ARARs) for the site. On the basis of the ARAR analysis, a total effective dose equivalent (TEDE) goal of 25 millirem per year (mrem/yr) was assumed for the site with a construction worker considered as the average member of the critical group. Derived concentration guideline levels (DCGLs) for residual radioactivity of the COCs in soil were developed for the Painesville Site using the RESRAD (Version 6.22) computer code (Yu et al. 2001), which was designed to estimate radiation doses and risks from RESidual RADioactive materials. The DCGLs represent activity levels above site average background activity corresponding to the 25-mrem/yr criterion for a construction worker scenario. The DCGLs are above the background activity concentrations and represent average concentration guidelines. The DCGLs and average background activity concentrations are provided in Table 1. The Final Feasibility Study Addendum (USACE 2005) provides a complete description of the derivation of the DCGLs for the Painesville Site. A post-remediation radiological dose assessment was performed to determine the potential radiation doses to a construction worker, consistent with the approach used to develop the DCGLs for the Painesville Site given in the Final Feasibility Study Addendum (USACE 2005) and ROD (USACE 2006). A second more conservative dose assessment was performed to determine the potential radiation doses to an urban resident who is assumed to live and garden on the site. To further evaluate the long-term protectiveness of the remedial action, a third dose assessment was conducted to determine the potential radiation doses to a hypothetical subsistence farmer. The primary difference between exposure to an urban resident versus a conservative subsistence farmer would be an increase in the amount of foodstuffs (homegrown produce, milk, and beef) produced/cultivated and consumed on-site.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2015

Enhancements to the TOUGH2 Simulator as Implemented in iTOUGH2

iTOUGH2 is a program for parameter estimation, sensitivity analysis, and uncertainty propagation analysis. It is based on the TOUGH2 simulator for non-isothermal multiphase, multicomponent flow and transport in fractured and porous media [Pruess, 1987, 1991, 2005, 2011; Falta et al., 1995; Pruess et al., 1999, 2002, 2012; Doughty, 2013]. The core of iTOUGH2 contains slightly modified versions of TOUGH2 modules. Most code modifications are editorial and do not affect the simulation results. As a result, standard TOUGH2 input files can be used in iTOUGH2, and identical results are obtained if iTOUGH2 is run in forward mode. However, a number of modifications have been made as described in this report. They enhance the functionality, flexibilitu, and eas-of-use of the forward simulator. This report complements the reports iTOUGH2 User's Guide, iTOUGH2 Command Referecne, and the collection of tutorial examples in iTOUGH2 Sample Problems.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2019

A Case Study with the HACCmk Kernel in SYCL

The SYCL standard specifies a cross-platform abstraction layer that enables programming of heterogeneous computing systems using standard C++ [1]. In the Open Computing Language (OpenCL) programming model, host and device codes are written in different languages [2 ]. To improve development productivity and performance portability, the SYCL programming model combines host and device codes for an application in a type-safe way. In this report, we are interested in applying the SYCL programming model to a computationally intensive routine derived from the Hardware Accelerated Cosmology Code (HACC) framework for a study on performance portability on a heterogeneous computing device. We use Intel® OneAPI toolkit [3] to build the OpenCL and SYCL programs, and evaluate the performance of both implementations on Intel® integrated GPUs. We find that the SYCL implementation can achieve the same performance as the OpenCL implementation after we specify a target backend for the compiler to build the SYCL program in offline compilation. Without the specification of a target backend, the runtime will have to compile intermediate device codes for a target platform. Such runtime overhead may become significant compared to the execution of a kernel on a target device. As the kernel routine is compute-bound, we evaluate the impact of the number of compute units upon the kernel’s raw performance using two GPUs. When the hardware resource is not underutilized, we can obtain almost linear performance speedup from 48 compute units to 72 compute units in offline compilation, which indicates that the number of compute units on a GPU are important to improving the raw performance of a compute-bound kernel. The experimental results show that SYCL is a promising programming model for heterogeneous computing. The remainder of the report is organized as follows: In Section II, we describe the SYCL programming model, the steps to map an OpenCL program to a SYCL program, and the architecture of an integrated GPU. Section III introduces the kernel routine, and presents the OpenCL and SYCL implementations of the kernel. In Section IV, we evaluate the performance of the implementations on the GPUs. Section V concludes the report.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2018

Energy and Energy Cost Savings Analysis of the 2018 IECC for Commercial Buildings

This report provides an assessment as to whether new buildings constructed to the commercial energy-efficiency provisions of the 2018 IECC would save energy and energy costs as compared to the 2015 IECC. The Commercial Energy Efficiency chapter in the 2018 IECC allows users to either follow the provisions in the IECC or use Standard 90.1-2016 as an alternative compliance path. PNNL also compared the energy performance of the 2018 IECC with the corresponding Standard 90.1-2016 to help states and local jurisdictions make informed decisions regarding model code adoption.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2025

Geant4 Event Biasing and Fast Simulation

Geant4 offers advanced event biasing techniques to significantly accelerate simulations involving rare events. Various biasing methods, such as leading particle selection, cross-section biasing, radioactive decay enhancement, and bremsstrahlung splitting, enable efficient event sampling, though they require careful handling. Additionally, Geant4 provides a Fast Simulation Interface, allowing the replacement of standard processes in specific region and for selected particles, enabling faster execution or external code integration. Applications of fast simulation include electromagnetic shower modeling in calorimeters, machine learning inference, and offloading tasks to specialized hardware like GPUs, making Geant4 a powerful tool for computationally demanding simulations.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2026

Highlight of IC project: w25_dreamxd

(left) The Earth’s radiation belts are donut-shaped regions containing MeV electrons (color contour for density) trapped by the magnetic field (white curves). We use DREAMxD code to model their dynamics. (right) We develop a new method to accelerate a key piece of the code – diffusion coefficient calculation. Comparing the compute time in node hours required by the standard approach to the compute time required for the fast method, it shows that the new method can be 100x faster for a large problem size.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2016

CLUMPY DISKS AS A TESTBED FOR FEEDBACK-REGULATED GALAXY FORMATION

We study the dependence of fragmentation in massive gas-rich galaxy disks at z >1 on stellar feedback schemes and hydrodynamical solvers, employing the GASOLINE2 SPH code and the lagrangian mesh-less code GIZMO in finite mass mode. Non-cosmological galaxy disk runs with the standard delayed-cooling blastwave feedback are compared with runs adopting a new superbubble feedback, which produces winds by modeling the detailed physics of supernova-driven bubbles and leads to efficient self-regulation of star formation. We find that, with blastwave feedback, massive star-forming clumps form in comparable number and with very similar masses in GASOLINE2 and GIZMO. Typical clump masses are in the range 10{sup 7}–10{sup 8} M {sub ⊙}, lower than in most previous works, while giant clumps with masses above 10{sup 9} M {sub ⊙} are exceedingly rare. By contrast, superbubble feedback does not produce massive star-forming bound clumps as galaxies never undergo a phase of violent disk instability. In this scheme, only sporadic, unbound star-forming overdensities lasting a few tens of Myr can arise, triggered by non-linear perturbations from massive satellite companions. We conclude that there is severe tension between explaining massive star-forming clumps observed at z >1 primarily as the result of disk fragmentation driven by gravitational instability and the prevailing view of feedback-regulated galaxy formation. The link between disk stability and star formation efficiency should thus be regarded as a key testing ground for galaxy formation theory.

79 ASTRONOMY AND ASTROPHYSICS↗
NASA NTRS1978

Standardized development of computer software. Part 2: Standards

This monograph contains standards for software development and engineering. The book sets forth rules for design, specification, coding, testing, documentation, and quality assurance audits of software; it also contains detailed outlines for the documentation to be produced.

Tausworthe, R. C.↗