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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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All sourcesNASA NTRSDOE OSTI
DOE OSTI2018

P4: Portable Parallel Processing Pipelines for Interactive Information Visualization

We present P4, an information visualization toolkit that combines declarative design specification and GPU computing for building high-performance interactive systems. Most of the existing information visualization toolkits do not harness the power of parallel processors in today's mainstream computers. P4 leverages GPU computing to accelerate both data processing and visualization rendering for interactive visualization applications. P4's programming interface offers a declarative visualization grammar for rapid specifications of data transformations, visual encodings, and interactions. By simplifying the development of GPU-accelerated visualization systems while supporting a high degree of flexibility and customization for design specification, P4 narrows the gap between expressiveness and scalability in information visualization toolkits. Through a range of examples and benchmark tests, we demonstrate that P4 provides high efficiency for creating interactive visualizations and offers drastic performance improvement over current state-of-the-art toolkits.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2013

Theories of Strongly Nonequilibrium Phenomena, Especially Deformation and Fracture of Solids

The major focus of the research program supported by this grant was the development of the shear-transformation-zone (STZ) theory of amorphous plasticity and its application to theories of dynamic fracture. In retrospect, the project was remarkably successful. It produced a deep understanding of the formability and strength of bulk metallic glasses [see, especially, refs 5, 6, 19] , and a predictive theory of shear-banding instabilities [17] . The shear-band analysis led, peripherally, to a first understanding of the origin of sharp stress drops during large earthquakes [22]. An important theme that emerged during these studies was the role of an effective temperature as a quantitative measure of the state of disorder induced by shear deformations. This theme led to what now appears to be a fundamental advance in nonequilibrium thermodynamics [6,23,24,25]. Much of this work has been summarized in a review article [26].

36 MATERIALS SCIENCE↗
DOE OSTI2016

Lattice QCD Calculation of Nucleon Structure

It is emphasized in the 2015 NSAC Long Range Plan that "understanding the structure of hadrons in terms of QCD's quarks and gluons is one of the central goals of modern nuclear physics." Over the last three decades, lattice QCD has developed into a powerful tool for ab initio calculations of strong-interaction physics. Up until now, it is the only theoretical approach to solving QCD with controlled statistical and systematic errors. Since 1985, we have proposed and carried out first-principles calculations of nucleon structure and hadron spectroscopy using lattice QCD which entails both algorithmic development and large-scale computer simulation. We started out by calculating the nucleon form factors -- electromagnetic, axial-vector, πNN, and scalar form factors, the quark spin contribution to the proton spin, the strangeness magnetic moment, the quark orbital angular momentum, the quark momentum fraction, and the quark and glue decomposition of the proton momentum and angular momentum. The first round of calculations were done with Wilson fermions in the `quenched' approximation where the dynamical effects of the quarks in the sea are not taken into account in the Monte Carlo simulation to generate the background gauge configurations. Beginning in 2000, we have started implementing the overlap fermion formulation into the spectroscopy and structure calculations. This is mainly because the overlap fermion honors chiral symmetry as in the continuum. It is going to be more and more important to take the symmetry into account as the simulations move closer to the physical point where the u and d quark masses are as light as a few MeV only. We began with lattices which have quark masses in the sea corresponding to a pion mass at ~ 300 MeV and obtained the strange form factors, charm and strange quark masses, the charmonium spectrum and the D s meson decay constant f D s , the strangeness and charmness, the meson mass decomposition and the strange quark spin from the anomalous Ward identity. Recently, we have started to include multiple lattices with different lattice spacings and different volumes including large lattices at the physical pion mass point. We are getting quite close to being able to calculate the hadron structure at the physical point and to do the continuum and large volume extrapolations, which is our ultimate aim. We have now finished several projects which have included these systematic corrections. They include the leptonic decay width of the ρ, the πN sigma and strange sigma terms, and the strange quark magnetic moment. Over the years, we have also studied hadron spectroscopy with lattice calculations and in phenomenology. These include Roper resonance, pentaquark state, charmonium spectrum, glueballs, scalar mesons a 0 (1450) and σ(600) and other scalar mesons, and the 1 -+ meson. In addition, we have employed the canonical approach to explore the first-order phase transition and the critical point at finite density and finite temperature. We have also discovered a new parton degree of freedom -- the connected sea partons, from the path-integral formulation of the hadronic tensor, which explains the experimentally observed Gottfried sum rule violation. Combining experimental result on the strange parton distribution, the CT10 global fitting results of the total u and d anti-partons and the lattice result of the ratio of the momentum fraction of the strange vs that of u or d in the disconnected insertion, we have shown that the connected sea partons can be isolated. In this final technical report, we shall present a few representative highlights that have been achieved in the project.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2018

DOE Grand Junction Office Marks 75 Years of Contribution to the Nation's Defense Program - 18380

On July 26, 2016, the former US Department of Energy (DOE) Grand Junction Office was listed on the National Register of Historic Places in recognition of its important, historic roles in the Manhattan Project and the Cold War. The work done from Grand Junction, Colorado, was an important component of the nation's defense program; however, because of the classified nature of the work, little of this history was originally available to the public. In 1943, the privately-owned site that later became the Grand Junction Office was purchased by the US government for the Colorado Area Office for the US Army Corps of Engineers Manhattan Engineer District (MED). The Colorado Area Office's mission was to procure and process uranium as part of a nationwide effort to build an atomic bomb. This race to build a bomb ahead of Nazi Germany became known as the Manhattan Project. Approximately 14% of the uranium obtained for the Manhattan Project was from Colorado Plateau ore-the largest source of domestic uranium ore known at the time. Uranium extracted from vanadium mill tailings was concentrated into uranium oxide, or 'yellowcake,' and shipped by rail to a facility in Tonawanda, New York, for further refinement. At the conclusion of World War II, the military MED mission ended, and the Grand Junction site became the principal US Atomic Energy Commission (AEC) office for acquiring and exploring for domestic uranium. The Colorado Raw Materials Office's primary objective was to increase the stockpile of fissionable material as rapidly as possible. To do that, AEC incentivized private industry and invited individual prospectors to locate uranium ores on public lands of the Colorado Plateau. Seemingly overnight, the small city of Grand Junction was transformed into a booming, modern metropolis and the national center of uranium exploration. Program operations in Grand Junction later included those of the National Uranium Resource Evaluation (NURE) program, the Uranium Mill Tailings Radiation Control Act (UMTRCA), vicinity properties cleanup, decontamination and decommissioning, and long-term surveillance and maintenance of legacy sites. In 2001, DOE transferred most of the original Grand Junction 55.7-acre site to the Riverview Technology Corporation, a business-development nonprofit sponsored by Mesa County and the City of Grand Junction. The US Department of Energy Office of Legacy Management continues to operate from leased facilities onsite. The Office of Legacy Management will host the 2018 Long-Term Stewardship Conference in Grand Junction on August 20-23. Conference attendees are invited to participate in a special 75. anniversary celebration at the Grand Junction Office where they will have the opportunity to learn more about the office's historic past, its ongoing and expanding work, and its goals of informing future generations. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2015

Better Buildings Neighborhood Program Single-Family Home Upgrade Project Dataset

Building project data for 75,110 single-family homes upgraded between July 1, 2010, and September 30, 2013 from the Better Building Neighborhood Program. This dataset includes a documentation file and three data tables. Reported data for some elements have been transformed and data for some upgraded homes have been omitted to protect privacy. See documentation file for details.

ARRA↗
DOE OSTI2020

Cooperative Routing for an Air–Ground Vehicle Team—Exact Algorithm, Transformation Method, and Heuristics

This paper considers a cooperative vehicle routing problem for an intelligence, surveillance, and reconnaissance mission in the presence of communication constraints between the vehicles. The proposed framework uses a ground vehicle and an unmanned aerial vehicle (UAV) that travel cooperatively and visit a set of targets while satisfying the communication constraints. The problem is formulated as a mixed-integer linear program, and a branch-and-cut algorithm is developed to solve the problem to optimality. Furthermore, a transformation method and a heuristic are also developed for the problem. The effectiveness of all the algorithms is corroborated through extensive computational experiments on several randomly generated instances. Furthermore, this paper is motivated by an intelligence, surveillance, and reconnaissance mission involving a single unmanned aerial vehicle (UAV) and a ground vehicle, where the vehicles must coordinate their activity in the presence of communication constraints. The combination of a small UAV and a ground vehicle is an ideal platform for such missions, since small UAVs can fly at low altitudes and can avoid obstacles or threats that would be problematic for the ground vehicle alone. This paper addresses the coordinated routing problem involving these two vehicles and presents an algorithm to obtain an optimal solution for this problem, fast heuristics to obtain good feasible solutions, and also a transformation method to transform any instance of this cooperative vehicle routing problem to an instance of the one-in-a-set traveling salesman problem.

33 ADVANCED PROPULSION SYSTEMS↗
DOE OSTI2016

A experimental research program on chirality at the LHC

Heavy-ion collisions provide a unique opportunity to investigate the fundamental laws of physics of the strong force. The extreme conditions created by the collisions within a finite volume are akin to the properties of the deconfined partonic state which existed very shortly after the Big Bang and just prior to visible matter formation in the Universe. In this state massless quarks and gluons (partons) are ``quasi free" particles, the so-called Quark Gluon Plasma (QGP). By following the expansion and cooling of this state, we will map out the process of nucleonic matter formation, which occurs during the phase transition. The fundamental properties of this early partonic phase of matter are not well understood, but they are essential for confirming QCD (Quantum Chromo-Dynamics) and the Standard Model. The specific topic, chiral symmetry restoration, has been called ``the remaining puzzle of QCD.'' This puzzle can only be studied in the dense partonic medium generated in heavy-ion collisions. The research objectives of this proposal are the development and application of new analysis strategies to study chirality and the properties of the medium above the QGP phase transition using hadronic resonances detected with the ALICE experiment at the Large Hadron Collider (LHC) at the CERN research laboratory in Switzerland. This grant funded a new effort at the University of Texas at Austin (UT Austin) to investigate the Quark Gluon Plasma (QGP) at the highest possible energy of 2.76 TeV per nucleon at the Large Hadron Collider (LHC) at CERN via the ALICE experiment. The findings added to our knowledge of the dynamical evolution and the properties of the hot, dense matter produced in heavy-ion collisions, and provided a deeper understanding of multi-hadron interactions in these extreme nuclear matter systems. Our group contributed as well to the hardware and software for the ALICE USA-funded Calorimeter Detector (EMCal). The LHC research program and its connection to fundamental questions in high energy, nuclear and astrophysics has triggered the imagination of many young students worldwide. The studies also promoted the early involvement of students and young postdocs in a large, multi-national research effort abroad, which provided them with substantial experience and skills prior to choosing their career path. The undergraduate program, in conjunction with the Freshman Research Initiative at UT Austin, allowed the students to complete a research project within the field of Nuclear Physics.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2021

Los Alamos National Laboratory’s Contingent Labor Transformation with SAP Fieldglass [Slides]

LANL continues to expand our mission, increasing demand for a robust Contingent Labor program. Our remote location makes finding and attracting workers difficult. Our existing Contingent Labor program did not cover all workers or contracts. We had outsourced management services, including a Fieldglass instance that was 3rd party managed. The end of life of our current contract for Contingent Labor management propelled us to pursue a comprehensive change to our approach.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2015

Morphology-dependent phase transformation of y-Al2O3

The phase transformations of platelet- and rod-shaped ?-Al2O3 were investigated and compared to that of a commercial sample by XRD, BET surface area measurements, Transmission Electron Microscopy (TEM), solid state 27Al-NMR and ethanol temperature programmed desorption (TPD) after sequential annealing in air up to 1100 oC. After annealing at 1100 oC, commercial ?-Al2O3 mostly transformed into a-Al2O3 with drastic surface area reduction (from 200 m2/g to 25 m2/g). Interestingly, platelet- and rod-shaped ?-Al2O3 which showed exactly the same XRD patterns transformed into different phases upon the high temperature calcinations. Platelet-shaped ?-Al2O3 transformed into ?-phase while the rod-shaped ?-Al2O3 transformed into the d-phase and not to the a-polymorph. Both platelet- and rod-shaped aluminas retained significantly higher surface area (~60 m2/g) than the commercial one after the same treatment at 1100 oC. These results suggest that the phase transformation in ?-Al2O3 is strongly affected by not only the crystal structure of the starting material, but its morphology as well. Ethanol TPD from platelet- and rod-shaped alumina after 1100 oC annealing, showed significantly different desorption profiles which suggest different surface characteristics even though they had almost the same surface areas. These different phase transformations were also supported by solid state 27Al-NMR. After 1100oC annealing commercial alumina showed the presence of mostly octahedral Al3+ ions, but the other two samples displayed even higher number of tetrahedral Al3+ ions than the initial ?-Al2O3. Morphological changes were also confirmed by TEM. All these results consistently suggest the morphology-dependent phase transformations of ?-Al2O3 and the improved thermal stability of platelet- and rod- shaped ?-Al2O3 in comparison to a commercial ?-Al2O3. J.Sz. acknowledges the US Department of Energy (DOE), Office of Science, Office of Basic Energy Sciences (BES), Division of Chemical Sciences, Geosciences & Biosciences for the support of this work.

Lee, Jaekyoung↗
DOE OSTI2025

Overview of the Neutron Radiography Reactor (NRAD) for Neutron Imaging and In-Core Experiment Capabilities at Idaho National Laboratory

NRAD is a 250-kilowatt TRIGA research reactor that first went online at INL in 1977. (TRIGA stands for Training, Research, Isotopes, General Atomics.) Historically, NRAD was utilized as a neutron radiography reactor that provides comprehensive, non-destructive information about the internal condition of irradiated nuclear fuel. Idaho National Laboratory (INL) has multiple nuclear fuels research and development programs that routinely evaluate irradiated fuels using neutron radiography at NRAD. In recent years, NRAD has gone through a transformation from the single purpose radiography reactor for which it was designed into a multipurpose research reactor, and expanding its in-core irradiation capabilities to support a broader mission for the US Department of Energy (DOE) Nuclear Energy (NE) programs, Basic Energy Science (BES) Programs, as well as Fusion Energy programs. NRAD is a designated user facility under the DOE Nuclear Science User Facility (NSUF) program, and is available for access for general public via a competitive proposal process. More information about NSUF and NRAD are available from the website: https://nsuf.inl.gov/Home/Facility/654.

11 - NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2018

Energy Efficiency and Infrastructure Upgrades on Nuclear Clean-up Sites: The Hanford Experience - 18641

The Hanford site, located in southeastern Washington, produced much of our nation's weapons-grade plutonium for the Defense nuclear weapons program. This production lasted the better part of four decades with production ending in 1987. Since 1987, the focus of the Hanford site has turned to clean-up activities. Mission Support Alliance (MSA) is the integrator of the multi-contractor effort to clean up the Hanford site. MSA collaborates with the U.S. Department of Energy (DOE) and all Hanford site contractors in finding and implementing new, cost-saving, safe and practical solutions to cleanup challenges with a continual focus on innovative processes and technologies that reduce costs, energy use and bring safety improvements to the site. Support Services include environmental integration and land management; fleet and road maintenance; water/electric and utilities; cyber security and information management as well as the preservation of the site's cultural artifacts. This paper describes the process, challenges, and focus on infrastructure upgrade and energy efficiency projects in the context of a multi-contractor nuclear clean-up site. Project development and new technology deployment at Hanford has long been plagued with economic challenges. For example, despite extensive auditing, analysis, and project development, most of the energy-related projects on the Hanford site have gone unfunded due to the low cost of electricity, the relatively high cost of labor, and costs associated with detailed safety and cultural reviews. - The Hanford site is a direct-service customer of the Bonneville Power Administration (BPA) and has a marginal electricity rate of $0.033/kWh. - Labor costs on the Hanford site track high because of the requirements associated with the safety and security necessary to operate a legacy nuclear weapons complex. - In partnership with three federally recognized and other affected Native American tribes (Yakama Nation, Confederated Tribes of the Umatilla Indian Reservation, the Nez Perce Tribe, and Wanapum People), most activities on the Hanford site are afforded in-depth cultural reviews. To work within these constraints, the MSA Energy Management team has embarked on a three-pronged approach to energy project development: Program Visibility: The MSA Energy Management team has promoted both project opportunities and requirements across the Hanford site. This information comes in the form of site-wide newsletters, group meetings, e-mails, success stories, and recognition of staff. Single-point Analysis: To by-pass the inevitable duplications of effort, learning curve issues, and to improve project consistency/delivery, the MSA Energy Management team serves as the single resource to the site for energy project analysis. This resource includes initial assessment, engineering analysis, efficiency calculation and project recommendations. Contractor/utility Interface: In addition to the infrastructure under its own purview, MSA provides all support services for the contractor/utility interface. These activities include formulation and submission of incentive-based efficiency projects, project tracking, and incentive awards. All incentive awards are forwarded to the relevant contractor and then highlighted in the visibility campaign. Successful energy efficiency projects at Hanford have included high efficiency heating, ventilation, air conditioning (HVAC) systems, interior and exterior lighting/lighting control systems, pump and motor systems, and the right-sizing of transformers and area-wide electrical distribution systems. Prior to the initiation of this program and structure (roughly 3 years ago) the average annual energy efficiency incentive applied for and received was under $10,000, with an annual energy savings of approximately 36,000 kilowatt hours (kWh). In fiscal year 2017, the annual incentive received was over $419,000, with identified energy savings of over 1.3 million kWh. Details and case studies of the major project accomplishments are included. The success of this program can be traced to an understanding of the constraints, the development of a program to address these constraints, and good communication/coordination across DOE and the multiple contractors serving the Hanford site. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2016

SU-F-J-94: Development of a Plug-in Based Image Analysis Tool for Integration Into Treatment Planning

Purpose: To extend the functionality of a commercial treatment planning system (TPS) to support (i) direct use of quantitative image-based metrics within treatment plan optimization and (ii) evaluation of dose-functional volume relationships to assist in functional image adaptive radiotherapy. Methods: A script was written that interfaces with a commercial TPS via an Application Programming Interface (API). The script executes a program that performs dose-functional volume analyses. Written in C#, the script reads the dose grid and correlates it with image data on a voxel-by-voxel basis through API extensions that can access registration transforms. A user interface was designed through WinForms to input parameters and display results. To test the performance of this program, image- and dose-based metrics computed from perfusion SPECT images aligned to the treatment planning CT were generated, validated, and compared. Results: The integration of image analysis information was successfully implemented as a plug-in to a commercial TPS. Perfusion SPECT images were used to validate the calculation and display of image-based metrics as well as dose-intensity metrics and histograms for defined structures on the treatment planning CT. Various biological dose correction models, custom image-based metrics, dose-intensity computations, and dose-intensity histograms were applied to analyze the image-dose profile. Conclusion: It is possible to add image analysis features to commercial TPSs through custom scripting applications. A tool was developed to enable the evaluation of image-intensity-based metrics in the context of functional targeting and avoidance. In addition to providing dose-intensity metrics and histograms that can be easily extracted from a plan database and correlated with outcomes, the system can also be extended to a plug-in optimization system, which can directly use the computed metrics for optimization of post-treatment tumor or normal tissue response models. Supported by NIH - P01 - CA059827.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2023

Studying performance portability of LAMMPS across diverse GPU-based platforms

The molecular dynamics simulation software, LAMMPS, utilizes the Kokkos acceleration library to port computation to a diverse set of architectures including those based on GPU accelerators. In addition to Kokkos, LAMMPS contains a vast code base that leverages the CUDA application programming interface using library functions such as cuFFT, CUDA's fast-fourier transform (FFT) library, and, more recently, also support for AMD's Heterogeneous Interface for Portability (HIP) that is rapidly growing. While preparing LAMMPS tests for the AMD GPU-based test system precursors to Frontier, we investigated several strategies for accelerating LAMMPS on AMD GPUs, using the AMD Instinct MI100 and MI250X. In this work, we integrated the HIP FFT library, hipFFT, into the particle-particle particle-mesh (PPPM) long-range solver, which allowed the porting of PPPM calculations to the GPUs. Kokkos behavior on the MI100 and MI250X was also investigated through the package kokkos command of LAMMPS, targeting communication, memory usage, and particle grid decomposition. The Tersoff, Reax, Lennard-Jones (LJ), EAM, Granular, and PPPM potentials were investigated in this effort, and results from these experiments are provided. In conclusion, the selected potentials were run on Spock (AMD Instinct MI100), Crusher (AMD Instinct MI250X), AFW HPC11 (NVIDIA A100) and Summit (NVIDIA V100), for comparison. Operational roofline models were constructed and analyzed for the Tersoff, Reax, and Lennard–Jones potentials on Crusher and Summit.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2020

Effect of pretreatment conditions on acidity and dehydration activity of CeO 2 -MeO x catalysts

A series of MeOx-modified CeO 2 (CeO 2 -MnO x , CeO 2 -ZnO, CeO 2 -MgO, CeO 2 -CaO, and CeO 2 -Na 2 O) catalysts were prepared by the impregnation of CeO 2 with corresponding metal nitrates. Acidity and oxidation state of cerium were investigated on both oxidized and reduced catalysts by employing Fourier Transform Infrared spectroscopy (FTIR) on adsorbed pyridine and in situ H 2 -Temperature Programmed Reduction/X-ray Absorption Spectroscopy (H 2 -TPR/XAS) techniques, respectively. Metal oxide addition tended to alter both type and number of acid sites on ceria. EXAFS data showed a significant difference in N Ce-O between unmodified and CeO 2 -MeO x , suggesting that added MeO x interferes with vacancy formation on ceria during reduction. Here, in comparison with air-pretreated samples, H 2 -pretreated ones under similar conversion of 1,5 pentanediol exhibited a higher selectivity towards linear alcohols. Alcohol conversion found to correlate with total acidity (i.e., Brønsted and Lewis). CeO 2 benefited from the addition of alkali (Na) or alkaline earth metals (Mg, Ca) by producing unsaturated alcohols.

1,5-Pentanediol↗
DOE OSTI2017

Domain Specific Language Support for Exascale

Domain-Specific Languages (DSLs) offer an attractive path to Exascale software since they provide expressive power through appropriate abstractions and enable domain-specific optimizations. But the advantages of a DSL compete with the difficulties of implementing a DSL, even for a narrowly defined domain. The DTEC project addresses how a variety of DSLs can be easily implemented to leverage existing compiler analysis and transformation capabilities within the ROSE open source compiler as part of a research program focusing on Exascale challenges. The OSU contributions to the DTEC project are in the area of code generation from high-level DSL descriptions, as well as verification of the automatically-generated code.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2017

Degradation of Adenine on the Martian Surface in the Presence of Perchlorates and Ionizing Radiation: A Reflectron Time-of-flight Mass Spectrometric Study

The aim of the present work is to unravel the radiolytic decomposition of adenine (C{sub 5}H{sub 5}N{sub 5}) under conditions relevant to the Martian surface. Being the fundamental building block of (deoxy)ribonucleic acids, the possibility of survival of this biomolecule on the Martian surface is of primary importance to the astrobiology community. Here, neat adenine and adenine–magnesium perchlorate mixtures were prepared and irradiated with energetic electrons that simulate the secondary electrons originating from the interaction of the galactic cosmic rays with the Martian surface. Perchlorates were added to the samples since they are abundant—and therefore relevant oxidizers on the surface of Mars—and they have been previously shown to facilitate the radiolysis of organics such as glycine. The degradation of the samples were monitored in situ via Fourier transformation infrared spectroscopy and the electron ionization quadruple mass spectrometric method; temperature-programmed desorption profiles were then collected by means of the state-of-the-art single photon photoionization reflectron time-of-flight mass spectrometry (PI-ReTOF-MS), allowing for the detection of the species subliming from the sample. The results showed that perchlorates do increase the destruction rate of adenine by opening alternative reaction channels, including the concurrent radiolysis/oxidation of the sample. This new pathway provides a plethora of different radiolysis products that were identified for the first time. These are carbon dioxide (CO{sub 2}), isocyanic acid (HNCO), isocyanate (OCN{sup −}), carbon monoxide (CO), and nitrogen monoxide (NO); an oxidation product containing carbonyl groups (R{sub 1}R{sub 2}–C=O) with a constrained five-membered cyclic structure could also be observed. Cyanamide (H{sub 2}N–C≡N) was detected in both irradiated samples as well.

79 ASTRONOMY AND ASTROPHYSICS↗