Search for squarks and gluinos in final states with hadronically decaying τ -leptons, jets, and missing transverse momentum using p p collisions at s = 13 TeV with the ATLAS detector
Not Available
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
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Results for “MISSE”
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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miss-SNF: a multimodal patient similarity network integration approach to handle completely missing data sources
Abstract Motivation Precision medicine leverages patient-specific multimodal data to improve prevention, diagnosis, prognosis, and treatment of diseases. Advancing precision medicine requires the non-trivial integration of complex, heterogeneous, and potentially high-dimensional data sources, such as multi-omics and clinical data. In the literature, several approaches have been proposed to manage missing data, but are usually limited to the recovery of subsets of features for a subset of patients. A largely overlooked problem is the integration of multiple sources of data when one or more of them are completely missing for a subset of patients, a relatively common condition in clinical practice. Results We propose miss-Similarity Network Fusion (miss-SNF), a novel general-purpose data integration approach designed to manage completely missing data in the context of patient similarity networks. miss-SNF integrates incomplete unimodal patient similarity networks by leveraging a non-linear message-passing strategy borrowed from the SNF algorithm. miss-SNF is able to recover missing patient similarities and is “task agnostic”, in the sense that can integrate partial data for both unsupervised and supervised prediction tasks. Experimental analyses on nine cancer datasets from The Cancer Genome Atlas (TCGA) demonstrate that miss-SNF achieves state-of-the-art results in recovering similarities and in identifying patients subgroups enriched in clinically relevant variables and having differential survival. Moreover, amputation experiments show that miss-SNF supervised prediction of cancer clinical outcomes and Alzheimer’s disease diagnosis with completely missing data achieves results comparable to those obtained when all the data are available. Availability and implementation miss-SNF code, implemented in R, is available at https://github.com/AnacletoLAB/missSNF.
Biochemistry & Molecular Biology↗
Testing of NASA LaRC Materials under MISSE 6 and MISSE 7 Missions
The objective of the Materials International Space Station Experiment (MISSE) is to study the performance of novel materials when subjected to the synergistic effects of the harsh space environment for several months. MISSE missions provide an opportunity for developing space qualifiable materials. Two lasers and a few optical components from NASA Langley Research Center (LaRC) were included in the MISSE 6 mission for long term exposure. MISSE 6 items were characterized and packed inside a ruggedized Passive Experiment Container (PEC) that resembles a suitcase. The PEC was tested for survivability due to launch conditions. MISSE 6 was transported to the international Space Station (ISS) via STS 123 on March 11. 2008. The astronauts successfully attached the PEC to external handrails of the ISS and opened the PEC for long term exposure to the space environment. The current plan is to bring the MISSE 6 PEC back to the Earth via STS 128 mission scheduled for launch in August 2009. Currently, preparations for launching the MISSE 7 mission are progressing. Laser and lidar components assembled on a flight-worthy platform are included from NASA LaRC. MISSE 7 launch is scheduled to be launched on STS 129 mission. This paper will briefly review recent efforts on MISSE 6 and MISSE 7 missions at NASA Langley Research Center (LaRC).
Prasad, Narasimha S.↗
The MISSE-9 Polymers and Composites Experiment Being Flown on the MISSE-Flight Facility
Materials on the exterior of spacecraft in low Earth orbit (LEO) are subject to extremely harsh environmental conditions, including various forms of radiation (cosmic rays, ultraviolet, x-ray, and charged particle radiation), micrometeoroids and orbital debris, temperature extremes, thermal cycling, and atomic oxygen (AO). These environmental exposures can result in erosion, embrittlement and optical property degradation of susceptible materials, threatening spacecraft performance and durability. To increase our understanding of space environmental effects such as AO erosion and radiation induced embrittlement of spacecraft materials, NASA Glenn has developed a series of experiments flown as part of the Materials International Space Station Experiment (MISSE) missions on the exterior of the International Space Station (ISS). These experiments have provided critical LEO space environment durability data such as AO erosion yield values for many materials and mechanical properties changes after long term space exposure. In continuing these studies, a new Glenn experiment has been proposed, and accepted, for flight on the new MISSE-Flight Facility (MISSE-FF). This experiment is called the Polymers and Composites Experiment and it will be flown as part of the MISSE-9 mission, the inaugural mission of MISSE-FF. Figure 1 provides an artist rendition of MISSE-FF ISS external platform. The MISSE-FF is manifested for launch on SpaceX-13.
De Groh, Kim K.↗
Estimated Environmental Exposures for MISSE-3 and MISSE-4
Both modeling techniques and a variety of measurements and observations were used to characterize the environmental conditions experienced by the specimens flown on the MISSE-3 (Materials International Space Station Experiment) and MISSE-4 space flight experiments. On August 3, 2006, astronauts Jeff Williams and Thomas Reiter attached MISSE-3 and -4 to the Quest airlock on ISS, where these experiments were exposed to atomic oxygen (AO), ultraviolet (UV) radiation, particulate radiation, thermal cycling, meteoroid/space debris impact, and the induced environment of an active space station. They had been flown to ISS during the July 2006 STS-121 mission. The two suitcases were oriented so that one side faced the ram direction and one side remained shielded from the atomic oxygen. On August 18,2007, astronauts Clay Anderson and Dave Williams retrieved MISSE-3 and-4 and returned them to Earth at the end of the STS-118 mission. Quantitative values are provided when possible for selected environmental factors. A meteoroid/debris impact survey was performed prior to de-integration at Langley Research Center. AO fluences were calculated based on mass loss and thickness loss of thin polymeric films of known AO reactivity. Radiation was measured with thermoluminescent detectors. Visual inspections under ambient and "black-light" at NASA LaRC, together with optical measurements on selected specimens, were the basis for the initial contamination level assessment.
Pippin, Gary↗
Estimated Environmental Exposures for MISSE-3 and MISSE-4
Describes the estimated environmental exposure for MISSE-2 and MISSE-4. These test beds, attached to the outside of the International Space Station, were planned for 3 years of exposure. This was changed to 1 year after MISSE-1 and -2 were in space for 4 years. MISSE-3 and -4 operate in a low Earth orbit space environment, which exposes them to a variety of assaults including atomic oxygen, ultraviolet radiation, particulate radiation, thermal cycling, and meteoroid/space debris impact, as well as contamination associated with proximity to an active space station. Measurements and determinations of atomic oxygen fluences, solar UV exposure levels, molecular contamination levels, and particulate radiation are included.
Finckenor, Miria M.↗
MBIR: A cryo-ET 3D reconstruction method that effectively minimizes missing wedge artifacts and restores missing information
Cryo-Electron Tomography (cryo-ET) has become an essential technique in revealing cellular and macromolecular assembly structures in their native states. However, due to radiation damage and the limited tilt range, cryo-ET suffers from low contrast and missing wedge artifacts, which limits the tomograms to low resolution and hinders further biological interpretation. We applied the Model-Based Iterative Reconstruction (MBIR) method to obtain tomographic 3D reconstructions of experimental cryo-ET datasets and demonstrated the advantages of MBIR in contrast improvement, missing wedge artifacts reduction, missing information restoration, and subtomogram averaging compared with other reconstruction approaches. Considering the outstanding reconstruction quality, MBIR has a great potential in the determination of high resolution biological structures with cryo-ET.
59 BASIC BIOLOGICAL SCIENCES↗
Results from Optical Coatings Flown on MISSE-1 and MISSE-2 and other Flight Experiments
Selected optically transparent materials and coatings flown on a number of low Earth orbit (LEO) materials flight experiments will be reviewed and discussed. Effects of flight exposure for both magnesium fluoride and lithium fluoride specimens will be presented. Individual specimens of magnesium fluoride were flown on the EOIM I11 Space Shuttle experiment, the Long Duration Exposure Facility (LDEF), the Optical Properties Monitor and Passive Optical Sample Assembly experiments on Mir, and MISSE-1 and MISSE-2 International Space Station packages. Subsequent to the LDEF retrieval and EOIM I11 experiment in 1992, the question of atomic oxygen reaction with magnesium fluoride was raised. Atomic oxygen and solar exposures, molecular contamination levels, and varying exposure durations will each be considered in evaluating any observed changes in optical properties. A comparison of the thermodynamics of oxidation of magnesium fluoride and lithium fluoride will be summarized. Elemental composition as a function of depth, as determined using XPS, will be discussed for selected specimens, to gain insight into reactions that are thermodynamically allowed under the LEO conditions.
Finckenor, Miria↗
Space Environmental Effects on Additively Manufactured Materials – Results from MISSE-9 and MISSE-10
The NASA Marshall Space Flight Center (MSFC) Space Environmental Effects (SEE) and Contamination Control (CC) teams prepared and characterized MISSE-9 and MISSE-10’s additively manufactured (AM) materials samples to investigate the effect of ultraviolet (UV) radiation, thermal cycling, outgassing, and temperature and provide data on the durability of these samples. Materials studied were polyetherimide (Ultem 1010 and 9085), electrostatic dissipative polyetherketoneketone (ESD-PEKK), also known commercially as Antero 840CN03, polycarbonate biocompatible per ISO 10993 USP Class VI (PC-ISO), and Inconel 718. Some samples were manufactured at MSFC, while 3D printer manufacturers Stratasys and Made In Space, Inc. (MIS) (now Redwire) participated in this effort to compare different vendors and printing setups. Results from nondestructive analyses and tensile testing are presented.
additive manufacturing↗
Search for large missing transverse momentum in association with one top-quark in proton-proton collisions at s $ \sqrt{s} $ = 13 TeV with the ATLAS detector
This paper describes a search for events with one top-quark and large missing transverse momentum in the final state. Data collected during 2015 and 2016 by the ATLAS experiment from 13 TeV proton–proton collisions at the LHC corresponding to an integrated luminosity of 36.1 fb –1 are used. Two channels are considered, depending on the leptonic or the hadronic decays of the W boson from the top quark. The obtained results are interpreted in the context of simplified models for dark-matter production and for the single production of a vector-like T quark. In the absence of significant deviations from the Standard Model background expectation, 95% confidence-level upper limits on the corresponding production cross-sections are obtained and these limits are translated into constraints on the parameter space of the models considered.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
Search for chargino and neutralino production in final states with a Higgs boson and missing transverse momentum at s√=13 TeV with the ATLAS detector
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72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
Search for new phenomena using the invariant mass distribution of same-flavour opposite-sign dilepton pairs in events with missing transverse momentum in $\sqrt{s}=13$ TeV pp collisions with the ATLAS detector
A search for new phenomena in final states containing an e + e - or μ + μ - pair, jets, and large missing transverse momentum is presented. This analysis makes use of proton–proton collision data with an integrated luminosity of 36.1 fb -1 , collected during 2015 and 2016 at a centre-of-mass energy s√=13 TeV with the ATLAS detector at the Large Hadron Collider. The search targets the pair production of supersymmetric coloured particles (squarks or gluinos) and their decays into final states containing an e + e - or μ + μ - pair and the lightest neutralino ($\sim\atop{χ}$ $0\atop{1}$) via one of two next-to-lightest neutralino ($\sim\atop{χ}$ $0\atop{2}$) decay mechanisms: $\sim\atop{χ}$ $0\atop{2}$→Z$\sim\atop{χ}$ $0\atop{1}$, where the Z boson decays leptonically leading to a peak in the dilepton invariant mass distribution around the Z boson mass; and $\sim\atop{χ}$ $0\atop{2}$→ℓ + ℓ - $\sim\atop{χ}$ $0\atop{1}$ with no intermediate ℓ + ℓ - resonance, yielding a kinematic endpoint in the dilepton invariant mass spectrum. The data are found to be consistent with the Standard Model expectation. Finally, results are interpreted using simplified models, and exclude gluinos and squarks with masses as large as 1.85 and 1.3 TeV at 95% confidence level, respectively.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
Subsurface biogeochemistry is a missing link between ecology and hydrology in dam-impacted river corridors
Not Available
Graham, Emily B. (ORCID:0000000246237076)↗
Locating the Missing Superconducting Electrons in the Overdoped Cuprates La 2 – x Sr x CuO 4 [Locating the Missing Superconducting Electrons in Overdoped Cuprates]
Overdoped high-temperature cuprate superconductors have often been understood within the standard BCS framework of superconductivity. However, measurements in a variety of overdoped cuprates indicate that the superfluid density is much smaller than expected from BCS theory and decreases smoothly to zero as the doping is increased. Here, we combine time-domain THz spectroscopy with kHz range mutual inductance measurements on the same overdoped La 2–x Sr x CuO 4 films to determine the total, superfluid, and uncondensed spectral weight as a function of doping. A significant fraction of the carriers remains uncondensed in a wide Drude-like peak as T → 0, while the superfluid density remains linear in temperature. These observations are seemingly inconsistent with existing, realistic theories of impurity scattering suppressing the superfluid density in a BCS-like d-wave superconductor. Furthermore, our large measurement frequency range gives us a unique look at the low frequency spectral weight distribution, which may suggest the presence of quantum phase fluctuations as the critical doping is approached.
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
Search for a new heavy gauge-boson resonance decaying into a lepton and missing transverse momentum in 36 fb$^{-1}$ of pp collisions at $\sqrt{s} = 13$ TeV with the ATLAS experiment
The results of a search for new heavy W ' bosons decaying to an electron or muon and a neutrino using proton–proton collision data at a centre-of-mass energy of √s = 13 TeV are presented. The dataset was collected in 2015 and 2016 by the ATLAS experiment at the Large Hadron Collider and corresponds to an integrated luminosity of 36.1 fb –1 . As no excess of events above the Standard Model prediction is observed, the results are used to set upper limits on the W ' boson cross-section times branching ratio to an electron or muon and a neutrino as a function of the W ' mass. Here, assuming a W ' boson with the same couplings as the Standard Model W boson, W ' masses below 5.1 TeV are excluded at the 95% confidence level.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
Analysis of International Space Station Materials on MISSE-3 and MISSE-4
For high-temperature applications (> 2,000 C) such as solid rocket motors, hypersonic aircraft, nuclear electric/thermal propulsion for spacecraft, and more efficient jet engines, creep becomes one of the most important design factors to be considered. Conventional creep-testing methods, where the specimen and test apparatus are in contact with each other, are limited to temperatures ~1,700 deg. C. Development of alloys for higher-temperature applications is limited by the availability of testing methods at temperatures above 2000 C. Development of alloys for applications requiring a long service life at temperatures as low as 1500 C, such as the next generation of jet turbine superalloys, is limited by the difficulty of accelerated testing at temperatures above 1700 0c. For these reasons, a new, non-contact creep-measurement technique is needed for higher temperature applications. A new non-contact method for creep measurements of ultra-high-temperature metals and ceramics has been developed and validated. Using the electrostatic levitation (ESL) facility at NASA Marshall Space Flight Center, a spherical sample is rotated quickly enough to cause creep deformation due to centrifugal acceleration. Very accurate measurement of the deformed shape through digital image analysis allows the stress exponent n to be determined very precisely from a single test, rather than from numerous conventional tests. Validation tests on single-crystal niobium spheres showed excellent agreement with conventional tests at 1985 C; however the non-contact method provides much greater precision while using only about 40 milligrams of material. This method is being applied to materials including metals and ceramics for noneroding throats in solid rockets and next-generation superalloys for turbine engines. Recent advances in the method and the current state of these new measurements will be presented.
Finckenor, Miria M.↗
Atomic Oxygen Interactions and the Design of MISSE-9 and MISSE-10 Experiments
Spacecraft in low Earth orbit (LEO) are subjected to harsh environmental conditions, including radiation (cosmic rays, ultraviolet, x-ray, and charged particle radiation), micrometeoroids and orbital debris, temperature extremes, thermal cycling, and atomic oxygen (AO). These environmental exposures can result in erosion, embrittlement and optical property degradation, threatening spacecraft performance and durability. While all of these environmental exposures can cause degradation to spacecraft components, AO is a particularly serious structural, thermal, and optical threat, to exterior oxidizable spacecraft components.
Atomic Oxygen↗
Materials International Space Station Experiment (MISSE): Overview, Accomplishments and Future Needs
Materials and devices used on the exterior of spacecraft in low Earth orbit (LEO) are subjected to environmental threats that can cause degradation in material properties, possibly threatening spacecraft mission success. These threats include: atomic oxygen (AO), ultraviolet and x-ray radiation, charged particle radiation, temperature extremes and thermal cycling, micrometeoroid and debris impacts, and contamination. Space environmental threats vary greatly based on spacecraft materials, thicknesses and stress levels, and the mission environment and duration. For more than a decade the Materials International Space Station Experiment (MISSE) has enabled the study of the long duration environmental durability of spacecraft materials in the LEO environment. The overall objective of MISSE is to test the stability and durability of materials and devices in the space environment in order to gain valuable knowledge on the performance of materials in space, as well as to enable lifetime predictions of new materials that may be used in future space flight. MISSE is a series of materials flight experiments, which are attached to the exterior of the International Space Station (ISS). Individual experiments were loaded onto suitcase-like trays, called Passive Experiment Containers (PECs). The PECs were transported to the ISS in the Space Shuttle cargo bay and attached to, and removed from, the ISS during extravehicular activities (EVAs). The PECs were retrieved after one or more years of space exposure and returned to Earth enabling post-flight experiment evaluation. MISSE is a multi-organization project with participants from the National Aeronautics and Space Administration (NASA), the Department of Defense (DoD), industry and academia. MISSE has provided a platform for environmental durability studies for thousands of samples and numerous devices, and it has produced many tangible impacts. Ten PECs (and one smaller tray) have been flown, representing MISSE 1 through MISSE 8, yielding long-duration space environmental performance and durability data that enable material validation, processing recertification and space qualification; improved predictions of materials and component lifetimes in space; model verification and development; and correlation factors between space-exposure and ground-facilities enabling more accurate in-space performance predictions based on ground-laboratory testing. A few of the many experiment results and observations, and their impacts, are provided. Those highlighted include examples on improved understanding of atomic oxygen scattering mechanisms, LEO coating durability results, and polymer erosion yields and their impacts on spacecraft design. The MISSE 2 Atomic Oxygen Scattering Chamber Experiment discovered that the peak flux of scattered AO was determined to be 45 deg from normal incidence, not the model predicted cosine dependence. In addition, the erosion yield (E(sub y)) of Kapton H for AO scattered off oxidized-Al is 22% of the E(sub y) of direct AO impingement. These results were used to help determine the degradation mechanism of a cesium iodide detector within the Hubble Space Telescope Cosmic Origins Spectrograph Experiment. The MISSE 6 Indium Tin Oxide (ITO) Degradation Experiment measured surface electrical resistance of ram and wake ITO coated samples. The data confirmed that ITO is a stable AO protective coating, and the results validated the durability of ITO conductive coatings for solar arrays for the Atmosphere-Space Transition 2 Explorer program. The MISSE 2, 6 and 7 Polymer Experiments have provided LEO AO Ey data on over 120 polymer and composites samples. The flight E(sub y) values were found to range from 3.05 x 10(exp -26) cu cm/atom for the AO resistant polymer CORIN to 9.14 x 10(exp -26) cu cm/atom for polyoxymethylene (POM). In addition, flying the same polymers on different missions has advanced the understanding of the AO E(sub y) dependency on solar exposure for polymers containing fluorine. The MISSE polymer results are highly requested and have impacted spacecraft design for WorldView-2 & -3, the Global Precipitation Measurement-Microwave Imager, and other spacecraft. The flight data has enabled the development of an Atomic Oxygen Erosion Predictive Tool that allows the erosion prediction of new and non-flown polymers. The data has also been used to develop a new NASA Technical Standards Handbook "Spacecraft Polymers Atomic Oxygen Durability Handbook." Many intangible benefits have also been derived from MISSE. For example, over 40 students have collaborated on Glenn's MISSE experiments, which have resulted in greater than $80K in student scholarships and awards in national and international science fairs. Students have also given presentations and won poster competition awards at international space conferences.
Flight Experiment↗