Ontology-Based High-Level Context Inference for Human Behavior Identification

PubMed Central

Villalonga, Claudia; Razzaq, Muhammad Asif; Khan, Wajahat Ali; Pomares, Hector; Rojas, Ignacio; Lee, Sungyoung; Banos, Oresti

2016-01-01

Recent years have witnessed a huge progress in the automatic identification of individual primitives of human behavior, such as activities or locations. However, the complex nature of human behavior demands more abstract contextual information for its analysis. This work presents an ontology-based method that combines low-level primitives of behavior, namely activity, locations and emotions, unprecedented to date, to intelligently derive more meaningful high-level context information. The paper contributes with a new open ontology describing both low-level and high-level context information, as well as their relationships. Furthermore, a framework building on the developed ontology and reasoning models is presented and evaluated. The proposed method proves to be robust while identifying high-level contexts even in the event of erroneously-detected low-level contexts. Despite reasonable inference times being obtained for a relevant set of users and instances, additional work is required to scale to long-term scenarios with a large number of users. PMID:27690050

Mapping virtual addresses to different physical addresses for value disambiguation for thread memory access requests

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gala, Alan; Ohmacht, Martin

A multiprocessor system includes nodes. Each node includes a data path that includes a core, a TLB, and a first level cache implementing disambiguation. The system also includes at least one second level cache and a main memory. For thread memory access requests, the core uses an address associated with an instruction format of the core. The first level cache uses an address format related to the size of the main memory plus an offset corresponding to hardware thread meta data. The second level cache uses a physical main memory address plus software thread meta data to store the memorymore » access request. The second level cache accesses the main memory using the physical address with neither the offset nor the thread meta data after resolving speculation. In short, this system includes mapping of a virtual address to a different physical addresses for value disambiguation for different threads.« less

Two-level main memory co-design: Multi-threaded algorithmic primitives, analysis, and simulation

DOE PAGES

Bender, Michael A.; Berry, Jonathan W.; Hammond, Simon D.; ...

2017-01-03

A challenge in computer architecture is that processors often cannot be fed data from DRAM as fast as CPUs can consume it. Therefore, many applications are memory-bandwidth bound. With this motivation and the realization that traditional architectures (with all DRAM reachable only via bus) are insufficient to feed groups of modern processing units, vendors have introduced a variety of non-DDR 3D memory technologies (Hybrid Memory Cube (HMC),Wide I/O 2, High Bandwidth Memory (HBM)). These offer higher bandwidth and lower power by stacking DRAM chips on the processor or nearby on a silicon interposer. We will call these solutions “near-memory,” andmore » if user-addressable, “scratchpad.” High-performance systems on the market now offer two levels of main memory: near-memory on package and traditional DRAM further away. In the near term we expect the latencies near-memory and DRAM to be similar. Here, it is natural to think of near-memory as another module on the DRAM level of the memory hierarchy. Vendors are expected to offer modes in which the near memory is used as cache, but we believe that this will be inefficient.« less

Present Situation of the Anti-Fatigue Processing of High-Strength Steel Internal Thread Based on Cold Extrusion Technology: A Review

NASA Astrophysics Data System (ADS)

Miao, Hong; Jiang, Cheng; Liu, Sixing; Zhang, Shanwen; Zhang, Yanjun

2017-03-01

The adoption of cold-extrusion forming for internal thread net forming becomes an important component of anti-fatigue processing with the development of internal thread processing towards high performance, low cost and low energy consumption. It has vast application foreground in the field of aviation, spaceflight, high speed train and etc. The internal thread processing and anti-fatigue manufacture technology are summarized. In terms of the perspective of processing quality and fatigue serving life, the advantages and disadvantages of the processing methods from are compared. The internal thread cold-extrusion processing technology is investigated for the purpose of improving the anti-fatigue serving life of internal thread. The superiorities of the plastic deformation law and surface integrity of the metal layer in the course of cold extrusion for improving its stability and economy are summed up. The proposed research forecasts the development tendency of the internal thread anti-fatigue manufacturing technology.

Purification of zebrafish erythrocytes as a means of identifying a novel regulator of haematopoiesis.

PubMed

Kulkeaw, Kasem; Inoue, Tomoko; Ishitani, Tohru; Nakanishi, Yoichi; Zon, Leonard I; Sugiyama, Daisuke

2018-02-01

Zebrafish embryos are useful to study haematopoietic gene function in vertebrates, although lack of antibodies to zebrafish proteins has limited the purification of specific cell populations. Here, we purified primitive zebrafish erythrocytes using 1, 5-bis{[2-(di-methylamino)ethyl]amino}-4, 8-dihydroxyanthracene-9, 10-dione (DRAQ5 TM ), a DNA-staining fluorescent dye. At 48-h post-fertilization, we sorted small-sized cells from embryos using forward scatter and found that they consisted of DRAQ5 high and DRAQ5 low populations. DRAQ5 high cells contained haemoglobin, lacked myeloperoxidase activity and expressed high levels of embryonic globin (hbae3 and hbbe1.1) mRNA, all characteristics of primitive erythrocytes. Following DRAQ5 TM analysis of gata1:dsRed transgenic embryos, we purified primitive DRAQ5 high dsRed+ erythrocytes from haematopoietic progenitor cells. Using this method, we identified docking protein 2 (Dok2) as functioning in differentiation of primitive erythrocytes. We conclude that DRAQ5 TM -based flow cytometry enables purification of primitive zebrafish erythrocytes. © 2017 John Wiley & Sons Ltd.

Remote mission specialist - A study in real-time, adaptive planning

NASA Technical Reports Server (NTRS)

Rokey, Mark J.

1990-01-01

A high-level planning architecture for robotic operations is presented. The remote mission specialist integrates high-level directives with low-level primitives executable by a run-time controller for command of autonomous servicing activities. The planner has been designed to address such issues as adaptive plan generation, real-time performance, and operator intervention.

A knowledge-based object recognition system for applications in the space station

NASA Technical Reports Server (NTRS)

Dhawan, Atam P.

1988-01-01

A knowledge-based three-dimensional (3D) object recognition system is being developed. The system uses primitive-based hierarchical relational and structural matching for the recognition of 3D objects in the two-dimensional (2D) image for interpretation of the 3D scene. At present, the pre-processing, low-level preliminary segmentation, rule-based segmentation, and the feature extraction are completed. The data structure of the primitive viewing knowledge-base (PVKB) is also completed. Algorithms and programs based on attribute-trees matching for decomposing the segmented data into valid primitives were developed. The frame-based structural and relational descriptions of some objects were created and stored in a knowledge-base. This knowledge-base of the frame-based descriptions were developed on the MICROVAX-AI microcomputer in LISP environment. The simulated 3D scene of simple non-overlapping objects as well as real camera data of images of 3D objects of low-complexity have been successfully interpreted.

Evaluating structural pattern recognition for handwritten math via primitive label graphs

NASA Astrophysics Data System (ADS)

Zanibbi, Richard; Mouchère, Harold; Viard-Gaudin, Christian

2013-01-01

Currently, structural pattern recognizer evaluations compare graphs of detected structure to target structures (i.e. ground truth) using recognition rates, recall and precision for object segmentation, classification and relationships. In document recognition, these target objects (e.g. symbols) are frequently comprised of multiple primitives (e.g. connected components, or strokes for online handwritten data), but current metrics do not characterize errors at the primitive level, from which object-level structure is obtained. Primitive label graphs are directed graphs defined over primitives and primitive pairs. We define new metrics obtained by Hamming distances over label graphs, which allow classification, segmentation and parsing errors to be characterized separately, or using a single measure. Recall and precision for detected objects may also be computed directly from label graphs. We illustrate the new metrics by comparing a new primitive-level evaluation to the symbol-level evaluation performed for the CROHME 2012 handwritten math recognition competition. A Python-based set of utilities for evaluating, visualizing and translating label graphs is publicly available.

Evict on write, a management strategy for a prefetch unit and/or first level cache in a multiprocessor system with speculative execution

DOEpatents

Gara, Alan; Ohmacht, Martin

2014-09-16

In a multiprocessor system with at least two levels of cache, a speculative thread may run on a core processor in parallel with other threads. When the thread seeks to do a write to main memory, this access is to be written through the first level cache to the second level cache. After the write though, the corresponding line is deleted from the first level cache and/or prefetch unit, so that any further accesses to the same location in main memory have to be retrieved from the second level cache. The second level cache keeps track of multiple versions of data, where more than one speculative thread is running in parallel, while the first level cache does not have any of the versions during speculation. A switch allows choosing between modes of operation of a speculation blind first level cache.

SMT-Aware Instantaneous Footprint Optimization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roy, Probir; Liu, Xu; Song, Shuaiwen

Modern architectures employ simultaneous multithreading (SMT) to increase thread-level parallelism. SMT threads share many functional units and the whole memory hierarchy of a physical core. Without a careful code design, SMT threads can easily contend with each other for these shared resources, causing severe performance degradation. Minimizing SMT thread contention for HPC applications running on dedicated platforms is very challenging, because they usually spawn threads within Single Program Multiple Data (SPMD) models. To address this important issue, we introduce a simple scheme for SMT-aware code optimization, which aims to reduce the memory contention across SMT threads.

Kinematic primitives for walking and trotting gaits of a quadruped robot with compliant legs.

PubMed

Spröwitz, Alexander T; Ajallooeian, Mostafa; Tuleu, Alexandre; Ijspeert, Auke Jan

2014-01-01

In this work we research the role of body dynamics in the complexity of kinematic patterns in a quadruped robot with compliant legs. Two gait patterns, lateral sequence walk and trot, along with leg length control patterns of different complexity were implemented in a modular, feed-forward locomotion controller. The controller was tested on a small, quadruped robot with compliant, segmented leg design, and led to self-stable and self-stabilizing robot locomotion. In-air stepping and on-ground locomotion leg kinematics were recorded, and the number and shapes of motion primitives accounting for 95% of the variance of kinematic leg data were extracted. This revealed that kinematic patterns resulting from feed-forward control had a lower complexity (in-air stepping, 2-3 primitives) than kinematic patterns from on-ground locomotion (νm4 primitives), although both experiments applied identical motor patterns. The complexity of on-ground kinematic patterns had increased, through ground contact and mechanical entrainment. The complexity of observed kinematic on-ground data matches those reported from level-ground locomotion data of legged animals. Results indicate that a very low complexity of modular, rhythmic, feed-forward motor control is sufficient for level-ground locomotion in combination with passive compliant legged hardware.

Kinematic primitives for walking and trotting gaits of a quadruped robot with compliant legs

PubMed Central

Spröwitz, Alexander T.; Ajallooeian, Mostafa; Tuleu, Alexandre; Ijspeert, Auke Jan

2014-01-01

In this work we research the role of body dynamics in the complexity of kinematic patterns in a quadruped robot with compliant legs. Two gait patterns, lateral sequence walk and trot, along with leg length control patterns of different complexity were implemented in a modular, feed-forward locomotion controller. The controller was tested on a small, quadruped robot with compliant, segmented leg design, and led to self-stable and self-stabilizing robot locomotion. In-air stepping and on-ground locomotion leg kinematics were recorded, and the number and shapes of motion primitives accounting for 95% of the variance of kinematic leg data were extracted. This revealed that kinematic patterns resulting from feed-forward control had a lower complexity (in-air stepping, 2–3 primitives) than kinematic patterns from on-ground locomotion (νm4 primitives), although both experiments applied identical motor patterns. The complexity of on-ground kinematic patterns had increased, through ground contact and mechanical entrainment. The complexity of observed kinematic on-ground data matches those reported from level-ground locomotion data of legged animals. Results indicate that a very low complexity of modular, rhythmic, feed-forward motor control is sufficient for level-ground locomotion in combination with passive compliant legged hardware. PMID:24639645

DOE Office of Scientific and Technical Information (OSTI.GOV)

Skochko, G.W.; Herrmann, T.P.

Axial load cycling fatigue tests of threaded fasteners are useful in determining fastener fatigue failure or design properties. By using appropriate design factors between the failure and design fatigue strengths, such tests are used to establish fatigue failure and design parameters of fasteners for axial and bending cyclic load conditions. This paper reviews the factors which influence the fatigue strength of low Alloy steel threaded fasteners, identifies those most significant to fatigue strength, and provides design guidelines based on the direct evaluation of fatigue tests of threaded fasteners. Influences on fatigue strength of thread manufacturing process (machining and rolling ofmore » threads), effect of fastener membrane and bending stresses, thread root radii, fastener sizes, fastener tensile strength, stress relaxation, mean stress, and test temperature are discussed.« less

Implications of Thermal Annealing on the Benzene Vapor Sensing Behavior of PEVA-Graphene Nanocomposite Threads.

PubMed

Patel, Sanjay V; Cemalovic, Sabina; Tolley, William K; Hobson, Stephen T; Anderson, Ryan; Fruhberger, Bernd

2018-03-23

The effect of thermal treatments, on the benzene vapor sensitivity of polyethylene (co-)vinylacetate (PEVA)/graphene nanocomposite threads, used as chemiresistive sensors, was investigated using DC resistance measurements, differential scanning calorimetry (DSC), and scanning electron microscopy (SEM). These flexible threads are being developed as low-cost, easy-to-measure chemical sensors that can be incorporated into smart clothing or disposable sensing patches. Chemiresistive threads were solution-cast or extruded from PEVA and <10% graphene nanoplatelets (by mass) in toluene. Threads were annealed at various temperatures and showed up to 2 orders of magnitude decrease in resistance with successive anneals. Threads heated to ≥80 °C showed improved limits of detection, resulting from improved signal-noise, when exposed to benzene vapor in dry air. In addition, annealing increased the speed of response and recovery upon exposure to and removal of benzene vapor. DSC results showed that the presence of graphene raises the freezing point, and may allow greater crystallinity, in the nanocomposite after annealing. SEM images confirm increased surface roughness/area, which may account for the increase response speed after annealing. Benzene vapor detection at 5 ppm is demonstrated with limits of detection estimated to be as low as 1.5 ppm, reflecting an order of magnitude improvement over unannealed threads.

Performance Analysis of and Tool Support for Transactional Memory on BG/Q

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schindewolf, M

2011-12-08

Martin Schindewolf worked during his internship at the Lawrence Livermore National Laboratory (LLNL) under the guidance of Martin Schulz at the Computer Science Group of the Center for Applied Scientific Computing. We studied the performance of the TM subsystem of BG/Q as well as researched the possibilities for tool support for TM. To study the performance, we run CLOMP-TM. CLOMP-TM is a benchmark designed for the purpose to quantify the overhead of OpenMP and compare different synchronization primitives. To advance CLOMP-TM, we added Message Passing Interface (MPI) routines for a hybrid parallelization. This enables to run multiple MPI tasks, eachmore » running OpenMP, on one node. With these enhancements, a beneficial MPI task to OpenMP thread ratio is determined. Further, the synchronization primitives are ranked as a function of the application characteristics. To demonstrate the usefulness of these results, we investigate a real Monte Carlo simulation called Monte Carlo Benchmark (MCB). Applying the lessons learned yields the best task to thread ratio. Further, we were able to tune the synchronization by transactifying the MCB. Further, we develop tools that capture the performance of the TM run time system and present it to the application's developer. The performance of the TM run time system relies on the built-in statistics. These tools use the Blue Gene Performance Monitoring (BGPM) interface to correlate the statistics from the TM run time system with performance counter values. This combination provides detailed insights in the run time behavior of the application and enables to track down the cause of degraded performance. Further, one tool has been implemented that separates the performance counters in three categories: Successful Speculation, Unsuccessful Speculation and No Speculation. All of the tools are crafted around IBM's xlc compiler for C and C++ and have been run and tested on a Q32 early access system.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Okada, Shoko; Weisman, Sarah; Trueman, Holly E.

Aposthonia gurneyi, an Australian webspinner species, is a primitive insect that constructs and lives in a silken tunnel which screens it from the attentions of predators. The insect spins silk threads from many tiny spines on its forelegs to weave a filmy sheet. We found that the webspinner silk fibers have a mean diameter of only 65 nm, an order of magnitude smaller than any previously reported insect silk. The purpose of such fine silk may be to reduce the metabolic cost of building the extensive tunnels. At the molecular level, the A. gurneyi silk has a predominantly beta-sheet proteinmore » structure. The most abundant clone in a cDNA library produced from the webspinner silk glands encoded a protein with extensive glycine-serine repeat regions. The GSGSGS repeat motif of the A. gurneyi silk protein is similar to the well-known GAGAGS repeat motif found in the heavy fibroin of silkworm silk, which also has beta-sheet structure. As the webspinner silk gene is unrelated to the silk gene of the phylogenetically distant silkworm, this is a striking example of convergent evolution.« less

Perceptual integration of kinematic components in the recognition of emotional facial expressions.

PubMed

Chiovetto, Enrico; Curio, Cristóbal; Endres, Dominik; Giese, Martin

2018-04-01

According to a long-standing hypothesis in motor control, complex body motion is organized in terms of movement primitives, reducing massively the dimensionality of the underlying control problems. For body movements, this low-dimensional organization has been convincingly demonstrated by the learning of low-dimensional representations from kinematic and EMG data. In contrast, the effective dimensionality of dynamic facial expressions is unknown, and dominant analysis approaches have been based on heuristically defined facial "action units," which reflect contributions of individual face muscles. We determined the effective dimensionality of dynamic facial expressions by learning of a low-dimensional model from 11 facial expressions. We found an amazingly low dimensionality with only two movement primitives being sufficient to simulate these dynamic expressions with high accuracy. This low dimensionality is confirmed statistically, by Bayesian model comparison of models with different numbers of primitives, and by a psychophysical experiment that demonstrates that expressions, simulated with only two primitives, are indistinguishable from natural ones. In addition, we find statistically optimal integration of the emotion information specified by these primitives in visual perception. Taken together, our results indicate that facial expressions might be controlled by a very small number of independent control units, permitting very low-dimensional parametrization of the associated facial expression.

A subjective study and an objective metric to quantify the granularity level of textures

NASA Astrophysics Data System (ADS)

Subedar, Mahesh M.; Karam, Lina J.

2015-03-01

Texture granularity is an important visual characteristic that is useful in a variety of applications, including analysis, recognition, and compression, to name a few. A texture granularity measure can be used to quantify the perceived level of texture granularity. The granularity level of the textures is influenced by the size of the texture primitives. A primitive is defined as the smallest recognizable repetitive object in the texture. If the texture has large primitives then the perceived granularity level tends to be lower as compared to a texture with smaller primitives. In this work we are presenting a texture granularity database referred as GranTEX which consists of 30 textures with varying levels of primitive sizes and granularity levels. The GranTEX database consists of both natural and man-made textures. A subjective study is conducted to measure the perceived granularity level of textures present in the GranTEX database. An objective metric that automatically measures the perceived granularity level of textures is also presented as part of this work. It is shown that the proposed granularity metric correlates well with the subjective granularity scores.

Presolar Materials in a Giant Cluster IDP of Probable Cometary Origin

NASA Technical Reports Server (NTRS)

Messenger, S.; Brownlee, D. E.; Joswiak, D. J.; Nguyen, A. N.

2015-01-01

Chondritic porous interplanetary dust particles (CP-IDPs) have been linked to comets by their fragile structure, primitive mineralogy, dynamics, and abundant interstellar materials. But differences have emerged between 'cometary' CP-IDPs and comet 81P/Wild 2 Stardust Mission samples. Particles resembling Ca-Al-rich inclusions (CAIs), chondrules, and amoeboid olivine aggregates (AOAs) in Wild 2 samples are rare in CP-IDPs. Unlike IDPs, presolar materials are scarce in Wild 2 samples. These differences may be due to selection effects, such as destruction of fine grained (presolar) components during the 6 km/s aerogel impact collection of Wild 2 samples. Large refractory grains observed in Wild 2 samples are also unlikely to be found in most (less than 30 micrometers) IDPs. Presolar materials provide a measure of primitive-ness of meteorites and IDPs. Organic matter in IDPs and chondrites shows H and N isotopic anomalies attributed to low-T interstellar or protosolar disk chemistry, where the largest anomalies occur in the most primitive samples. Presolar silicates are abundant in meteorites with low levels of aqueous alteration (Acfer 094 approximately 200 ppm) and scarce in altered chondrites (e.g. Semarkona approximately 20 ppm). Presolar silicates in minimally altered CP-IDPs range from approximately 400 ppm to 15,000 ppm, possibly reflecting variable levels of destruction in the solar nebula or statistical variations due to small sample sizes. Here we present preliminary isotopic and mineralogical studies of a very large CP-IDP. The goals of this study are to more accurately determine the abundances of presolar components of CP-IDP material for comparison with comet Wild 2 samples and meteorites. The large mass of this IDP presents a unique opportunity to accurately determine the abundance of pre-solar grains in a likely cometary sample.

Low-Resolution Spectroscopy of Primitive Asteroids: Progress Report for SARA/VSU Survey

NASA Technical Reports Server (NTRS)

Leake, M. A.; Nogues, J. P.; Gaines, J. K.; Looper, J. K.; Freitas, K. A.

2001-01-01

Progress on a low-resolution survey of primitive C-class asteroids continues using new equipment (and its associated problems) to understand aqueous alteration in the solar system. Additional information is contained in the original extended abstract.

Development of Fire Resistant/Heat Resistant Sewing Thread

DTIC Science & Technology

2016-03-01

Final 3. DATES COVERED (From - To) October 2014 – June 2015 4. TITLE AND SUBTITLE DEVELOPMENT OF FIRE RESISTANT /HEAT RESISTANT SEWING THREAD 5a...core to sheath ratio of 70:30 will offer a high performance, low cost sewing thread with required fire resistant /heat resistant properties. 15...Properties ............................................................................... 18        1      DEVELOPMENT OF  FIRE   RESISTANT /HEAT

Retention of primitive reflexes and delayed motor development in very low birth weight infants.

PubMed

Marquis, P J; Ruiz, N A; Lundy, M S; Dillard, R G

1984-06-01

Primitive reflexes and motor development were evaluated in 127 very low birth weight (VLBW) infants (birth weight less than 1501 grams) at four months corrected age. The asymmetrical tonic neck reflex, tonic labyrinth reflex, and Moro reflex were assessed for each child. The ability of each child to reach (obtain a red ring) and roll were observed. The child's performance on the gross motor scale of the Denver Development Screening Test was recorded. Thirty-seven term infants were administered identical evaluations at four months of age. The VLBW infants retained stronger primitive reflexes and exhibited a significantly higher incidence of motor delays than term infants. Significant correlations existed between the strength of the primitive reflexes and early motor development for VLBW infants. This study confirms a high incidence of motor delays among VLBW infants and demonstrates a clear association between retained primitive reflexes and delayed motor development in VLBW infants.

A fluid-mechanical sewing machine

NASA Astrophysics Data System (ADS)

Lister, John; Chiu-Webster, Sunny

2004-11-01

It is a breakfast-table experience that when a viscous fluid thread falls a sufficient height onto a stationary horizontal surface the thread is undergoes a coiling instability. We describe experimental observations of a viscous thread falling onto a steadily moving horizontal belt. Low (or zero) belt speeds produce coiling as expected. High belt speeds produce a steady thread, whose shape is well-predicted by theory for a stretching catenary with surface tension and inertia. Intermediate belt speeds show various modes of oscillation, which produce a variety of `stitching' patterns on the belt. The onset of oscillations is predicted theoretically.

PRIMitive Asteroids Spectroscopic Survey - PRIMASS: First Results

NASA Astrophysics Data System (ADS)

de Leon, Julia; Pinilla-Alonso, Noemi; Campins, Humberto; Lorenzi, Vania; Licandro, Javier; Morate, David; Tanga, Paolo; Cellino, Alberto; Delbo, Marco

2015-11-01

NASA OSIRIS-REx and JAXA Hayabusa 2 sample-return missions have targeted two near-Earth asteroids: (101955) Bennu and (162173) 1999 JU3, respectively. These are primitive asteroids that are believed to originate in the inner belt, where five distinct sources have been identified: four primitive collisional families (Polana, Erigone, Sulamitis, and Clarissa), and a population of low-albedo and low-inclination background asteroids. Identifying and characterizing the populations from which these two NEAs might originate will enchance the science return of the two missions.With this main objective in mind, we initiated in 2010 a spectroscopic survey in the visible and the near-infrared to characterize the primitive collisional families in the inner belt and the low-albedo background population. This is the PRIMitive Asteroids Spectroscopic Survey - PRIMASS. So far we have obtained more than 200 spectra using telescopes located at different observatories. PRIMASS uses a variety of ground based facilities. Most of the spectra have been obtained using the 10.4m Gran Telescopio Canarias (GTC), and the 3.6m Telescopio Nazionale Galileo (TNG), both located at the El Roque de los Muchachos Observatory (La Palma, Spain), and the 3.0m NASA Infrared Telescope Facility on Mauna Kea (Hawai, USA).We present the first results from our on-going survey (de Leon et al. 2015; Pinilla-Alonso et al. 2015; Morate et al. 2015), focused on the Polana and the Erigone primitive families, with visible and near-infrared spectra of more than 200 objects, most of them with no previous spectroscopic data. Our survey is already the largest database of primitive asteroids spectra, and we keep obtaining data on the Sulamitis and the Clarissa families, as well as on the background low-albedo population.

Supporting Graduate Student Writers with VoiceThread

ERIC Educational Resources Information Center

Gonzalez, Michelle; Moore, Noreen S.

2018-01-01

This qualitative case study examined the influence of the use of VoiceThread technology on the feedback process for thesis writing in two online asynchronous graduate courses. The influence on instructor feedback process and graduate student writers' perceptions of the use of VoiceThread were the foci of the study. Master's-level students (n = 18)…

During Threaded Discussions Are Non-Native English Speakers Always at a Disadvantage?

ERIC Educational Resources Information Center

Shafer Willner, Lynn

2014-01-01

When participating in threaded discussions, under what conditions might non¬native speakers of English (NNSE) be at a comparative disadvantage to their classmates who are native speakers of English (NSE)? This study compares the threaded discussion perspectives of closely-matched NNSE and NSE adult students having different levels of threaded…

A Review of Lightweight Thread Approaches for High Performance Computing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Castello, Adrian; Pena, Antonio J.; Seo, Sangmin

High-level, directive-based solutions are becoming the programming models (PMs) of the multi/many-core architectures. Several solutions relying on operating system (OS) threads perfectly work with a moderate number of cores. However, exascale systems will spawn hundreds of thousands of threads in order to exploit their massive parallel architectures and thus conventional OS threads are too heavy for that purpose. Several lightweight thread (LWT) libraries have recently appeared offering lighter mechanisms to tackle massive concurrency. In order to examine the suitability of LWTs in high-level runtimes, we develop a set of microbenchmarks consisting of commonlyfound patterns in current parallel codes. Moreover, wemore » study the semantics offered by some LWT libraries in order to expose the similarities between different LWT application programming interfaces. This study reveals that a reduced set of LWT functions can be sufficient to cover the common parallel code patterns and that those LWT libraries perform better than OS threads-based solutions in cases where task and nested parallelism are becoming more popular with new architectures.« less

Integrating end-to-end threads of control into object-oriented analysis and design

NASA Technical Reports Server (NTRS)

Mccandlish, Janet E.; Macdonald, James R.; Graves, Sara J.

1993-01-01

Current object-oriented analysis and design methodologies fall short in their use of mechanisms for identifying threads of control for the system being developed. The scenarios which typically describe a system are more global than looking at the individual objects and representing their behavior. Unlike conventional methodologies that use data flow and process-dependency diagrams, object-oriented methodologies do not provide a model for representing these global threads end-to-end. Tracing through threads of control is key to ensuring that a system is complete and timing constraints are addressed. The existence of multiple threads of control in a system necessitates a partitioning of the system into processes. This paper describes the application and representation of end-to-end threads of control to the object-oriented analysis and design process using object-oriented constructs. The issue of representation is viewed as a grouping problem, that is, how to group classes/objects at a higher level of abstraction so that the system may be viewed as a whole with both classes/objects and their associated dynamic behavior. Existing object-oriented development methodology techniques are extended by adding design-level constructs termed logical composite classes and process composite classes. Logical composite classes are design-level classes which group classes/objects both logically and by thread of control information. Process composite classes further refine the logical composite class groupings by using process partitioning criteria to produce optimum concurrent execution results. The goal of these design-level constructs is to ultimately provide the basis for a mechanism that can support the creation of process composite classes in an automated way. Using an automated mechanism makes it easier to partition a system into concurrently executing elements that can be run in parallel on multiple processors.

Circuit design tool. User's manual, revision 2

NASA Technical Reports Server (NTRS)

Miyake, Keith M.; Smith, Donald E.

1992-01-01

The CAM chip design was produced in a UNIX software environment using a design tool that supports definition of digital electronic modules, composition of these modules into higher level circuits, and event-driven simulation of these circuits. Our design tool provides an interface whose goals include straightforward but flexible primitive module definition and circuit composition, efficient simulation, and a debugging environment that facilitates design verification and alteration. The tool provides a set of primitive modules which can be composed into higher level circuits. Each module is a C-language subroutine that uses a set of interface protocols understood by the design tool. Primitives can be altered simply by recoding their C-code image; in addition new primitives can be added allowing higher level circuits to be described in C-code rather than as a composition of primitive modules--this feature can greatly enhance the speed of simulation.

Importance of Sox2 in maintenance of cell proliferation and multipotency of mesenchymal stem cells in low-density culture.

PubMed

Yoon, D S; Kim, Y H; Jung, H S; Paik, S; Lee, J W

2011-10-01

This study has aimed to repopulate 'primitive' cells from late-passage mesenchymal stem cells (MSCs) of poor multipotentiality and low cell proliferation rate, by simply altering plating density. Effects of low density culture compared t high density culture on late-passage bone marrow (BM)-derived MSCs and pluripotency markers of multipotentiality were investigated. Cell proliferation, gene expression, RNA interference and differentiation potential were assayed. We repopulated 'primitive' cells by replating late-passage MSCs at low density (17 cells/cm(2) ) regardless of donor age. Repopulated MSCs from low-density culture were smaller cells with spindle shaped morphology compared to MSCs from high-density culture. The latter had enhanced colony-forming ability, proliferation rate, and adipogenic and chondrogenic potential. Strong expression of osteogenic-related genes (Cbfa1, Dlx5, alkaline phosphatase and type Ι collagen) in late-passage MSCs was reduced by replating at low density, whereas expression of three pluripotency markers (Sox2, Nanog and Oct-4), Osterix and Msx2 reverted to levels of early-passage MSCs. Knockdown of Sox2 and Msx2 but not Nanog, using RNA interference, showed significant decrease in colony-forming ability. Specifically, knockdown of Sox2 significantly inhibited multipotentiality and cell proliferation. Our data suggest that plating density should be considered to be a critical factor for enrichment of 'primitive' cells from heterogeneous BM and that replicative senescence and multipotentiality of MSCs during in vitro expansion may be predominantly regulated through Sox2. © 2011 Blackwell Publishing Ltd.

High precision optomechanical assembly using threads as mechanical reference

NASA Astrophysics Data System (ADS)

Lamontagne, Frédéric; Desnoyers, Nichola; Bergeron, Guy; Cantin, Mario

2016-09-01

A convenient method to assemble optomechanical components is to use threaded interface. For example, lenses are often secured inside barrels using threaded rings. In other cases, multiple optical sub-assemblies such as lens barrels can be threaded to each other. Threads have the advantage to provide a simple assembly method, to be easy to manufacture, and to offer a compact mechanical design. On the other hand, threads are not considered to provide accurate centering between parts because of the assembly clearance between the inner and outer threads. For that reason, threads are often used in conjunction with precision cylindrical surfaces to limit the radial clearance between the parts to be centered. Therefore, tight manufacturing tolerances are needed on these pilot diameters, which affect the cost of the optical assembly. This paper presents a new optomechanical approach that uses threads as mechanical reference. This innovative method relies on geometric principles to auto-center parts to each other with a very low centering error that is usually less than 5 μm. The method allows to auto-center an optical group in a main barrel, to perform an axial adjustment of an optical group inside a main barrel, and to perform stacking of multiple barrels. In conjunction with the lens auto-centering method that also used threads as a mechanical reference, this novel solution opens new possibilities to realize a variety of different high precision optomechanical assemblies at lower cost.

Process Management and Exception Handling in Multiprocessor Operating Systems Using Object-Oriented Design Techniques. Revised Sep. 1988

NASA Technical Reports Server (NTRS)

Russo, Vincent; Johnston, Gary; Campbell, Roy

1988-01-01

The programming of the interrupt handling mechanisms, process switching primitives, scheduling mechanism, and synchronization primitives of an operating system for a multiprocessor require both efficient code in order to support the needs of high- performance or real-time applications and careful organization to facilitate maintenance. Although many advantages have been claimed for object-oriented class hierarchical languages and their corresponding design methodologies, the application of these techniques to the design of the primitives within an operating system has not been widely demonstrated. To investigate the role of class hierarchical design in systems programming, the authors have constructed the Choices multiprocessor operating system architecture the C++ programming language. During the implementation, it was found that many operating system design concerns can be represented advantageously using a class hierarchical approach, including: the separation of mechanism and policy; the organization of an operating system into layers, each of which represents an abstract machine; and the notions of process and exception management. In this paper, we discuss an implementation of the low-level primitives of this system and outline the strategy by which we developed our solution.

Nanofibre production in spiders without electric charge.

PubMed

Joel, Anna-Christin; Baumgartner, Werner

2017-06-15

Technical nanofibre production is linked to high voltage, because nanofibres are typically produced by electrospinning. In contrast, spiders have evolved a way to produce nanofibres without high voltage. These spiders are called cribellate spiders and produce nanofibres within their capture thread production. It is suggested that their nanofibres become frictionally charged when brushed over a continuous area on the calamistrum, a comb-like structure at the metatarsus of the fourth leg. Although there are indications that electrostatic charges are involved in the formation of the thread structure, final proof is missing. We proposed three requirements to validate this hypothesis: (1) the removal of any charge during or after thread production has an influence on the structure of the thread; (2) the characteristic structure of the thread can be regenerated by charging; and (3) the thread is attracted to or repelled from differently charged objects. None of these three requirements were proven true. Furthermore, mathematical calculations reveal that even at low charges, the calculated structural assembly of the thread does not match the observed reality. Electrostatic forces are therefore not involved in the production of cribellate capture threads. © 2017. Published by The Company of Biologists Ltd.

A Test of Durkheim's Theory of Suicide in Primitive Societies.

ERIC Educational Resources Information Center

Lester, David

1992-01-01

Classified primitive societies as high, moderate, or low on independent measures of social integration and social regulation to test Durkheim's theory of suicide. Estimated frequency of suicide did not differ between those societies predicted to have high, moderate, and low suicide rates. Durkheim's theory was not confirmed. (Author/NB)

Fanconi anemia genes are highly expressed in primitive CD34+ hematopoietic cells

PubMed Central

Aubé, Michel; Lafrance, Matthieu; Brodeur, Isabelle; Delisle, Marie-Chantal; Carreau, Madeleine

2003-01-01

Background Fanconi anemia (FA) is a complex recessive genetic disease characterized by progressive bone marrow failure (BM) and a predisposition to cancer. We have previously shown using the Fancc mouse model that the progressive BM failure results from a hematopoietic stem cell defect suggesting that function of the FA genes may reside in primitive hematopoietic stem cells. Methods Since genes involved in stem cell differentiation and/or maintenance are usually regulated at the transcription level, we used a semiquantitative RT-PCR method to evaluate FA gene transcript levels in purified hematopoietic stem cells. Results We show that most FA genes are highly expressed in primitive CD34-positive and negative cells compared to lower levels in more differentiated cells. However, in CD34- stem cells the Fancc gene was found to be expressed at low levels while Fancg was undetectable in this population. Furthermore, Fancg expression is significantly decreased in Fancc -/- stem cells as compared to wild-type cells while the cancer susceptibility genes Brca1 and Fancd1/Brac2 are upregulated in Fancc-/- hematopoietic cells. Conclusions These results suggest that FA genes are regulated at the mRNA level, that increased Fancc expression in LTS-CD34+ cells correlates with a role at the CD34+ differentiation stage and that lack of Fancc affects the expression of other FA gene, more specifically Fancg and Fancd1/Brca2, through an unknown mechanism. PMID:12809565

A Moiré Pattern-Based Thread Counter

NASA Astrophysics Data System (ADS)

Reich, Gary

2017-10-01

Thread count is a term used in the textile industry as a measure of how closely woven a fabric is. It is usually defined as the sum of the number of warp threads per inch (or cm) and the number of weft threads per inch. (It is sometimes confusingly described as the number of threads per square inch.) In recent years it has also become a subject of considerable interest and some controversy among consumers. Many consumers consider thread count to be a key measure of the quality or fineness of a fabric, especially bed sheets, and they seek out fabrics that advertise high counts. Manufacturers in turn have responded to this interest by offering fabrics with ever higher claimed thread counts (sold at ever higher prices), sometime achieving the higher counts by distorting the definition of the term with some "creative math." In 2005 the Federal Trade Commission noted the growing use of thread count in advertising at the retail level and warned of the potential for consumers to be misled by distortions of the definition.

Tubulin post-translational modifications in the primitive protist Trichomonas vaginalis.

PubMed

Delgado-Viscogliosi, P; Brugerolle, G; Viscogliosi, E

1996-01-01

Using several specific monoclonal antibodies, we investigated the occurrence and distribution of different post-translationally modified tubulin during interphase and division of the primitive flagellated protist Trichomonas vaginalis. Immunoblotting and immunofluorescence experiments revealed that interphasic microtubular structures of T. vaginalis contained acetylated and glutamylated but non-tyrosinated and non-glycylated [Brugerolle and Adoutte, 1988: Bio Systems 21: 255-268] tubulin. Immunofluorescence studies performed on dividing cells showed that the extranuclear mitotic spindle (or paradesmosis) was acetylated and glutamylated, which contrast with the ephemeral nature of this structure. Newly formed short axostyles also contained acetylated and glutamylated tubulin suggesting that both post-translational modifications might take place very early after assembly of microtubular structures. Our results indicate that acetylation and glutamylation of tubulin appeared early in the history of eukaryotes and could reflect the occurrence of post-translational modifications of tubulin in the primitive eukaryotic cells. These cells probably had a highly ordered cross-linked microtubular cytoskeleton in which microtubules showed a low level of subunit exchange dynamics.

Assembly of one-dimensional supramolecular objects: From monomers to networks

NASA Astrophysics Data System (ADS)

Sayar, Mehmet; Stupp, Samuel I.

2005-07-01

One-dimensional supramolecular aggregates can form networks at exceedingly low concentrations. Recent experiments in several laboratories, including our own, have demonstrated the formation of gels by these systems at concentrations well under 1% by weight. The systems of interest in our laboratory form either cylindrical nanofibers or ribbons as a result of strong noncovalent interactions among monomers. The stiffness and interaction energies among these thread-like objects can vary significantly depending on the chemical structure of the monomers used. We have used Monte Carlo simulations to study the structure of the threads and their ability to form networks through bundle formation. The persistence length of the threads was found to be strongly affected not only by stiffness, but also by the strength of attractive two-body interactions among thread segments. The relative values of stiffness and attractive two-body interaction strength determine if threads collapse or create bundles. Only in the presence of sufficiently long threads and bundle formation can these systems assemble into networks of high connectivity.

Oxygen as a factor in eukaryote evolution - Some effects of low levels of oxygen on Saccharomyces cerevisiae

NASA Technical Reports Server (NTRS)

Jahnke, L.; Klein, H. P.

1979-01-01

A comparative study of the effects of varying levels of oxygen on some of the metabolic functions of the primitive eukaryote, Saccharomyces cerevisiae, has shown that these cells are responsive to very low levels of oxygen: the level of palmitoyl-Co A desaturase was greatly enhanced by only 0.03 vol % oxygen. Similarly, an acetyl-CoA synthetase associated predominantly with anaerobic growth was stimulated by as little as 0.1% oxygen, while an isoenzyme correlated with aerobic growth was maximally active at much higher oxygen levels (greater than 1%). Closely following this latter pattern were three mitochondrial enzymes that attained maximal activity only under atmospheric levels of oxygen.

Design evolution of a low shock release nut

NASA Technical Reports Server (NTRS)

Otth, D. H.; Gordon, W.

1976-01-01

Design improvements and detailed functional analyses are reviewed to trace the development of a pyroactuated release device with segmented thread design from its intermediate design into one that reduces the levels of shock spectra generated during its operation by 50%. Comparisons of shock output and internal load distribution are presented, along with descriptions of mechanical operation for both designs. Results also show the potential areas where design development activity can gain further progress in lowering actuation shock levels.

Representation of Muscle Synergies in the Primate Brain.

PubMed

Overduin, Simon A; d'Avella, Andrea; Roh, Jinsook; Carmena, Jose M; Bizzi, Emilio

2015-09-16

Evidence suggests that the CNS uses motor primitives to simplify movement control, but whether it actually stores primitives instead of computing solutions on the fly to satisfy task demands is a controversial and still-unanswered possibility. Also in contention is whether these primitives take the form of time-invariant muscle coactivations ("spatial" synergies) or time-varying muscle commands ("spatiotemporal" synergies). Here, we examined forelimb muscle patterns and motor cortical spiking data in rhesus macaques (Macaca mulatta) handling objects of variable shape and size. From these data, we extracted both spatiotemporal and spatial synergies using non-negative decomposition. Each spatiotemporal synergy represents a sequence of muscular or neural activations that appeared to recur frequently during the animals' behavior. Key features of the spatiotemporal synergies (including their dimensionality, timing, and amplitude modulation) were independently observed in the muscular and neural data. In addition, both at the muscular and neural levels, these spatiotemporal synergies could be readily reconstructed as sequential activations of spatial synergies (a subset of those extracted independently from the task data), suggestive of a hierarchical relationship between the two levels of synergies. The possibility that motor cortex may execute even complex skill using spatiotemporal synergies has novel implications for the design of neuroprosthetic devices, which could gain computational efficiency by adopting the discrete and low-dimensional control that these primitives imply. We studied the motor cortical and forearm muscular activity of rhesus macaques (Macaca mulatta) as they reached, grasped, and carried objects of varied shape and size. We applied non-negative matrix factorization separately to the cortical and muscular data to reduce their dimensionality to a smaller set of time-varying "spatiotemporal" synergies. Each synergy represents a sequence of cortical or muscular activity that recurred frequently during the animals' behavior. Salient features of the synergies (including their dimensionality, timing, and amplitude modulation) were observed at both the cortical and muscular levels. The possibility that the brain may execute even complex behaviors using spatiotemporal synergies has implications for neuroprosthetic algorithm design, which could become more computationally efficient by adopting the discrete and low-dimensional control that they afford. Copyright © 2015 the authors 0270-6474/15/3512615-10$15.00/0.

Prion Disease Induces Alzheimer Disease-Like Neuropathologic Changes

PubMed Central

Tousseyn, Thomas; Bajsarowicz, Krystyna; Sánchez, Henry; Gheyara, Ania; Oehler, Abby; Geschwind, Michael; DeArmond, Bernadette; DeArmond, Stephen J.

2016-01-01

We examined the brains of 266 patients with prion diseases (PrionD) and found that 46 (17%) had Alzheimer disease (AD)-like changes. To explore potential mechanistic links between PrionD and AD, we exposed human brain aggregates (Hu BrnAggs) to brain homogenate from a patient with sporadic Creutzfeldt-Jakob disease (CJD) and found that the neurons in the Hu BrnAggs produced many β-amyloid (β42) inclusions, whereas uninfected, control-exposed Hu BrnAggs did not. Western blots of 20-pooled CJD-infected BrnAggs verified higher Aβ42 levels than controls. We next examined the CA1 region of the hippocampus from 14 patients with PrionD and found that 5 patients had low levels of scrapie-associated prion protein (PrPSc), many Aβ42 intraneuronal inclusions, low APOE-4, and no significant nerve cell loss. Seven patients had high levels of PrPSc, low Aβ42, high APOE-4 and 40% nerve cell loss, suggesting that APOE-4 and PrPSc together cause neuron loss in PrionD. There were also increased levels of hyperphosphorylated tau protein (Hτ) and Hτ-positive neuropil threads and neuron bodies in both PrionD and AD groups. The brains of 6 age-matched control patients without dementia did not contain Aβ42 deposits; however, there were rare Hτ-positive threads in 5 controls and 2 controls had a few Hτ-positive nerve cell bodies. We conclude that PrionD may trigger biochemical changes similar to AD and suggest that PrionD are diseases of PrPSc, Aβ42, APOE-4 and abnormal tau. PMID:26226132

Low-noise nozzle valve

NASA Technical Reports Server (NTRS)

Gwin, Hal S. (Inventor); Aaron, James (Inventor)

1990-01-01

A low noise, variable discharage area, valve is constructed having opposed recesses within which a pair of gates are slidably disposed. Each of the gates is provided with upstream edges having a radius thereon, the radius enabling smooth, accelerated, low noise flow therebetween. The gates are further provided with tracks along each side, which in turn slide along splines set in the side walls of the valve. A threaded rod which rotates in a threaded insert in a rear wall of each of the gates, serves to move the gates within their respective recesses.

Investigating Patterns of Participation in an Online Support Group for Problem Drinking: a Social Network Analysis.

PubMed

Urbanoski, Karen; van Mierlo, Trevor; Cunningham, John

2017-10-01

This study contributes to emerging literature on online health networks by modeling communication patterns between members of a moderated online support group for problem drinking. Using social network analysis, we described members' patterns of joint participation in threads, parsing out the role of site moderators, and explored differences in member characteristics by network position. Posts made to the online support group of Alcohol Help Centre during 2013 were structured as a two-mode network of members (n = 205) connected via threads (n = 506). Metrics included degree centrality, clique membership, and tie strength. The network consisted of one component and no cliques of members, although most made few posts and a small number communicated only with the site's moderators. Highly active members were older and tended to have started posting prior to 2013. The distribution of members across threads varied from threads containing posts by one member to others that connected multiple members. Moderators accounted for sizable proportions of the connectivity between both members and threads. After 5 years of operation, the AHC online support group appears to be fairly cohesive and stable, in the sense that there were no isolated subnetworks comprised of specific types of members or devoted to specific topics. Participation and connectedness at the member-level was varied, however, and tended to be low on average. The moderators were among the most central in the network, although there were also members who emerged as central and dedicated contributors to the online discussions across topics. Study findings highlight a number of areas for consideration by online support group developers and managers.

Paralex: An Environment for Parallel Programming in Distributed Systems

DTIC Science & Technology

1991-12-07

distributed systems is coni- parable to assembly language programming for traditional sequential systems - the user must resort to low-level primitives ...to accomplish data encoding/decoding, communication, remote exe- cution, synchronization , failure detection and recovery. It is our belief that... synchronization . Finally, composing parallel programs by interconnecting se- quential computations allows automatic support for heterogeneity and fault tolerance

Evaluation of the increase in threading dislocation during the initial stage of physical vapor transport growth of 4H-SiC

NASA Astrophysics Data System (ADS)

Suo, Hiromasa; Tsukimoto, Susumu; Eto, Kazuma; Osawa, Hiroshi; Kato, Tomohisa; Okumura, Hajime

2018-06-01

The increase in threading dislocation during the initial stage of physical vapor transport growth of n-type 4H-SiC crystals was evaluated by cross-sectional X-ray topography. Crystals were grown under two different temperature conditions. A significant increase in threading dislocation was observed in crystals grown at a high, not low, temperature. The local strain distribution in the vicinity of the grown/seed crystal interface was evaluated using the electron backscatter diffraction technique. The local nitrogen concentration distribution was also evaluated by time-of-flight secondary ion mass spectrometry. We discuss the relationship between the increase in threading dislocation and the local strain due to thermal stress and nitrogen concentration.

Influence of fine threads and platform-switching on crestal bone stress around implant-a three-dimensional finite element analysis.

PubMed

Khurana, Pardeep; Sharma, Arun; Sodhi, Kiranmeet Kaur

2013-12-01

The aims of this study were to investigate the effect of implant fine threads on crestal bone stress compared to a standard smooth implant collar and to analyze how different abutment diameters influenced the crestal bone stress level. Three-dimensional finite element imaging was used to create a cross-sectional model in SolidWorks 2007 software of an implant (5-mm platform and 10 mm in length) placed in the premolar region of the mandible. The implant model was created to resemble a commercially available fine thread implant. Abutments of different diameters (5.0 mm: standard, 4.5 mm, 4.0 mm, and 3.5 mm) were loaded with a force of 100 N at 90° vertical and 40° oblique angles. Finite element analysis was done in COSMOSWorks software, which was used to analyze the stress patterns in bone, especially in the crestal region. Upon loading, the fine thread implant model had greater stress at the crestal bone adjacent to the implant than the smooth neck implant in both vertical and oblique loading. When the abutment diameter decreased progressively from 5.0 mm to 4.5 mm to 4 mm and to 3.5 mm the thread model showed a reduction of stress at the crestal bone level from 23.2 MPa to 15.02 MPa for fine thread and from 22.7 to 13.5 MPa for smooth collar implant group after vertical loading and from 43.7 MPa to 33.1 MPa in fine thread model and from 36.9 to 20.5 MPa in smooth collar implant model after oblique loading. Fine threads increase crestal stress upon loading. Reduced abutment diameter that is platform switching resulted in less stress translated to the crestal bone in the fine thread and smooth neck.

46 CFR 56.30-20 - Threaded joints.

Code of Federal Regulations, 2014 CFR

2014-10-01

..., inches Maximum pressure, p.s.i.g. Above 2″ (Not permitted in Class I piping service.) Above 1″ up to 2... joints appear in the low temperature piping section. 2 Threaded joints in hydraulic systems are permitted above the pressures indicated for the nominal sizes shown when commercially available components such as...

46 CFR 56.30-20 - Threaded joints.

Code of Federal Regulations, 2011 CFR

2011-10-01

..., inches Maximum pressure, p.s.i.g. Above 2″ (Not permitted in Class I piping service.) Above 1″ up to 2... joints appear in the low temperature piping section. 2 Threaded joints in hydraulic systems are permitted above the pressures indicated for the nominal sizes shown when commercially available components such as...

46 CFR 56.30-20 - Threaded joints.

Code of Federal Regulations, 2013 CFR

2013-10-01

..., inches Maximum pressure, p.s.i.g. Above 2″ (Not permitted in Class I piping service.) Above 1″ up to 2... joints appear in the low temperature piping section. 2 Threaded joints in hydraulic systems are permitted above the pressures indicated for the nominal sizes shown when commercially available components such as...

46 CFR 56.30-20 - Threaded joints.

Code of Federal Regulations, 2012 CFR

2012-10-01

..., inches Maximum pressure, p.s.i.g. Above 2″ (Not permitted in Class I piping service.) Above 1″ up to 2... joints appear in the low temperature piping section. 2 Threaded joints in hydraulic systems are permitted above the pressures indicated for the nominal sizes shown when commercially available components such as...

46 CFR 56.30-20 - Threaded joints.

Code of Federal Regulations, 2010 CFR

2010-10-01

..., inches Maximum pressure, p.s.i.g. Above 2″ (Not permitted in Class I piping service.) Above 1″ up to 2... joints appear in the low temperature piping section. 2 Threaded joints in hydraulic systems are permitted above the pressures indicated for the nominal sizes shown when commercially available components such as...

Low backlash direct drive actuator

DOEpatents

Kuklo, Thomas C.

1994-01-01

A low backlash direct drive actuator is described which comprises a motor such as a stepper motor having at least 200 steps per revolution; a two part hub assembly comprising a drive hub coaxially attached to the shaft of the motor and having a plurality of drive pins; a driven hub having a plurality of bores in one end thereof in alignment with the drive pins in the drive hub and a threaded shaft coaxially mounted in an opposite end of the driven hub; and a housing having a central bore therein into which are fitted the drive hub and driven hub, the housing having a motor mount on one end thereof to which is mounted the stepper motor, and a closed end portion with a threaded opening therein coaxial with the central bore in the housing and receiving therein the threaded shaft attached to the driven hub. Limit switches mounted to the housing cooperate with an enlarged lip on the driven hub to limit the lateral travel of the driven hub in the housing, which also acts to limit the lateral travel of the threaded shaft which functions as a lead screw.

Does Simultaneous Liposuction Adversely Affect the Outcome of Thread Lifts? A Preliminary Result.

PubMed

Lee, Yong Woo; Park, Tae Hwan

2018-04-11

Along with advances in thread lift techniques and materials, ancillary procedures such as fat grafting, liposuction, or filler injections have been performed simultaneously. Some surgeons think that these ancillary procedures might affect the aesthetic outcomes of thread lifting possibly due to inadvertent injury to threads or loosening of soft tissue via passing the cannula in the surgical plane of the thread lifts. The purpose of the current study is to determine the effect of such ancillary procedures on the outcome of thread lifts in the human and cadaveric setting. We used human abdominal tissue after abdominoplasty and cadaveric faces. In the abdominal tissue, liposuction parallel to the parallel axis was performed in one area for 5 min. We counted 30 passes when liposuction was performed in one direction. This was repeated as we changed the direction of passages. The plane of thread lifts (dermal vs subcutaneous) and angle between liposuction and thread lifts (parallel vs perpendicular) were differentiated in this abdominal tissue study group. Then, we performed parallel or perpendicular thread lifts using a small slit incision. Using a tensiometer, the maximum holding strength was measured when pulling the thread out of the skin as much as possible. We also used faces of cadavers to prove whether the finding in human abdominal tissue is really valid with corresponding techniques. Our pilot study using abdominal tissue showed that liposuction after thread lifts adversely affects it regardless of the vector of thread lifts. In the cadaveric study, however, liposuction prior to thread lifting does not significantly affect the holding strength of thread lifts. Liposuction or fat grafting in the appropriate layer would not be a hurdle to safely performing simultaneous thread lifts if the target lift tissue is intra-SMAS or just above the SMAS layer. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

RGCA: A Reliable GPU Cluster Architecture for Large-Scale Internet of Things Computing Based on Effective Performance-Energy Optimization

PubMed Central

Chen, Qingkui; Zhao, Deyu; Wang, Jingjuan

2017-01-01

This paper aims to develop a low-cost, high-performance and high-reliability computing system to process large-scale data using common data mining algorithms in the Internet of Things (IoT) computing environment. Considering the characteristics of IoT data processing, similar to mainstream high performance computing, we use a GPU (Graphics Processing Unit) cluster to achieve better IoT services. Firstly, we present an energy consumption calculation method (ECCM) based on WSNs. Then, using the CUDA (Compute Unified Device Architecture) Programming model, we propose a Two-level Parallel Optimization Model (TLPOM) which exploits reasonable resource planning and common compiler optimization techniques to obtain the best blocks and threads configuration considering the resource constraints of each node. The key to this part is dynamic coupling Thread-Level Parallelism (TLP) and Instruction-Level Parallelism (ILP) to improve the performance of the algorithms without additional energy consumption. Finally, combining the ECCM and the TLPOM, we use the Reliable GPU Cluster Architecture (RGCA) to obtain a high-reliability computing system considering the nodes’ diversity, algorithm characteristics, etc. The results show that the performance of the algorithms significantly increased by 34.1%, 33.96% and 24.07% for Fermi, Kepler and Maxwell on average with TLPOM and the RGCA ensures that our IoT computing system provides low-cost and high-reliability services. PMID:28777325

RGCA: A Reliable GPU Cluster Architecture for Large-Scale Internet of Things Computing Based on Effective Performance-Energy Optimization.

PubMed

Fang, Yuling; Chen, Qingkui; Xiong, Neal N; Zhao, Deyu; Wang, Jingjuan

2017-08-04

This paper aims to develop a low-cost, high-performance and high-reliability computing system to process large-scale data using common data mining algorithms in the Internet of Things (IoT) computing environment. Considering the characteristics of IoT data processing, similar to mainstream high performance computing, we use a GPU (Graphics Processing Unit) cluster to achieve better IoT services. Firstly, we present an energy consumption calculation method (ECCM) based on WSNs. Then, using the CUDA (Compute Unified Device Architecture) Programming model, we propose a Two-level Parallel Optimization Model (TLPOM) which exploits reasonable resource planning and common compiler optimization techniques to obtain the best blocks and threads configuration considering the resource constraints of each node. The key to this part is dynamic coupling Thread-Level Parallelism (TLP) and Instruction-Level Parallelism (ILP) to improve the performance of the algorithms without additional energy consumption. Finally, combining the ECCM and the TLPOM, we use the Reliable GPU Cluster Architecture (RGCA) to obtain a high-reliability computing system considering the nodes' diversity, algorithm characteristics, etc. The results show that the performance of the algorithms significantly increased by 34.1%, 33.96% and 24.07% for Fermi, Kepler and Maxwell on average with TLPOM and the RGCA ensures that our IoT computing system provides low-cost and high-reliability services.

AthenaMT: upgrading the ATLAS software framework for the many-core world with multi-threading

NASA Astrophysics Data System (ADS)

Leggett, Charles; Baines, John; Bold, Tomasz; Calafiura, Paolo; Farrell, Steven; van Gemmeren, Peter; Malon, David; Ritsch, Elmar; Stewart, Graeme; Snyder, Scott; Tsulaia, Vakhtang; Wynne, Benjamin; ATLAS Collaboration

2017-10-01

ATLAS’s current software framework, Gaudi/Athena, has been very successful for the experiment in LHC Runs 1 and 2. However, its single threaded design has been recognized for some time to be increasingly problematic as CPUs have increased core counts and decreased available memory per core. Even the multi-process version of Athena, AthenaMP, will not scale to the range of architectures we expect to use beyond Run2. After concluding a rigorous requirements phase, where many design components were examined in detail, ATLAS has begun the migration to a new data-flow driven, multi-threaded framework, which enables the simultaneous processing of singleton, thread unsafe legacy Algorithms, cloned Algorithms that execute concurrently in their own threads with different Event contexts, and fully re-entrant, thread safe Algorithms. In this paper we report on the process of modifying the framework to safely process multiple concurrent events in different threads, which entails significant changes in the underlying handling of features such as event and time dependent data, asynchronous callbacks, metadata, integration with the online High Level Trigger for partial processing in certain regions of interest, concurrent I/O, as well as ensuring thread safety of core services. We also report on upgrading the framework to handle Algorithms that are fully re-entrant.

Carbon Nanotube Thread Electrochemical Cell: Detection of Heavy Metals.

PubMed

Zhao, Daoli; Siebold, David; Alvarez, Noe T; Shanov, Vesselin N; Heineman, William R

2017-09-19

In this work, all three electrodes in an electrochemical cell were fabricated based on carbon nanotube (CNT) thread. CNT thread partially insulated with a thin polystyrene coating to define the microelectrode area was used as the working electrode; bare CNT thread was used as the auxiliary electrode; and a micro quasi-reference electrode was fabricated by electroplating CNT thread with Ag and then anodizing it in chloride solution to form a layer of AgCl. The Ag|AgCl coated CNT thread electrode provided a stable potential comparable to the conventional liquid-junction type Ag|AgCl reference electrode. The CNT thread auxiliary electrode provided a stable current, which is comparable to a Pt wire auxiliary electrode. This all-CNT thread three electrode cell has been evaluated as a microsensor for the simultaneous determination of trace levels of heavy metal ions by anodic stripping voltammetry (ASV). Hg 2+ , Cu 2+ , and Pb 2+ were used as a representative system for this study. The calculated detection limits (based on the 3σ method) with a 120 s deposition time are 1.05, 0.53, and 0.57 nM for Hg 2+ , Cu 2+ , and Pb 2+ , respectively. These electrodes significantly reduce the dimensions of the conventional three electrode electrochemical cell to the microscale.

Distinguishing synchronous and time-varying synergies using point process interval statistics: motor primitives in frog and rat

PubMed Central

Hart, Corey B.; Giszter, Simon F.

2013-01-01

We present and apply a method that uses point process statistics to discriminate the forms of synergies in motor pattern data, prior to explicit synergy extraction. The method uses electromyogram (EMG) pulse peak timing or onset timing. Peak timing is preferable in complex patterns where pulse onsets may be overlapping. An interval statistic derived from the point processes of EMG peak timings distinguishes time-varying synergies from synchronous synergies (SS). Model data shows that the statistic is robust for most conditions. Its application to both frog hindlimb EMG and rat locomotion hindlimb EMG show data from these preparations is clearly most consistent with synchronous synergy models (p < 0.001). Additional direct tests of pulse and interval relations in frog data further bolster the support for synchronous synergy mechanisms in these data. Our method and analyses support separated control of rhythm and pattern of motor primitives, with the low level execution primitives comprising pulsed SS in both frog and rat, and both episodic and rhythmic behaviors. PMID:23675341

Microfluidic thread based electroanalytical system for green chromatographic separations.

PubMed

Agustini, Deonir; Fedalto, Lucas; Bergamini, Márcio F; Marcolino-Junior, Luiz Humberto

2018-02-13

The use of miniaturized chromatographic systems is an important strategy for reducing the consumption of supplies related to separations, allowing the development of more sustainable analytical methodologies. However, the high cost and complexity in the production of these systems combined with the operational difficulties and the need for the use of solvent and sample pretreatment are challenges to be overcome in order to make the chromatographic methods greener. Here, we report the construction and development of a low cost microfluidic system for green and solvent-free chromatographic separations with electrochemical detection integrated into cotton threads without the use of any mechanical pumping to transport the solutions. The manufacture of the proposed system was performed by simple assembly of the components, with the separation of the species based on an ion exchange mechanism and detection using gold electrodes manufactured directly on the cotton threads. A linear range of 0.025-5.0 mM was obtained for the effective separation of ascorbic acid (AA) and dopamine (DA) with detection limits of 2.89 μM (for AA) and 4.41 μM (for DA). Each analysis was performed at a low cost (less than 0.01 dollars), and with a small volume of waste generated (107.1 μL). So, the proposed system was successfully employed to determine the levels of AA and DA present in the tears of healthy volunteers without sample pretreatment, indicating the good analytical performance of the system and the possibility of performing greener chromatographic separations.

Multi-threading performance of Geant4, MCNP6, and PHITS Monte Carlo codes for tetrahedral-mesh geometry.

PubMed

Han, Min Cheol; Yeom, Yeon Soo; Lee, Hyun Su; Shin, Bangho; Kim, Chan Hyeong; Furuta, Takuya

2018-05-04

In this study, the multi-threading performance of the Geant4, MCNP6, and PHITS codes was evaluated as a function of the number of threads (N) and the complexity of the tetrahedral-mesh phantom. For this, three tetrahedral-mesh phantoms of varying complexity (simple, moderately complex, and highly complex) were prepared and implemented in the three different Monte Carlo codes, in photon and neutron transport simulations. Subsequently, for each case, the initialization time, calculation time, and memory usage were measured as a function of the number of threads used in the simulation. It was found that for all codes, the initialization time significantly increased with the complexity of the phantom, but not with the number of threads. Geant4 exhibited much longer initialization time than the other codes, especially for the complex phantom (MRCP). The improvement of computation speed due to the use of a multi-threaded code was calculated as the speed-up factor, the ratio of the computation speed on a multi-threaded code to the computation speed on a single-threaded code. Geant4 showed the best multi-threading performance among the codes considered in this study, with the speed-up factor almost linearly increasing with the number of threads, reaching ~30 when N  =  40. PHITS and MCNP6 showed a much smaller increase of the speed-up factor with the number of threads. For PHITS, the speed-up factors were low when N  =  40. For MCNP6, the increase of the speed-up factors was better, but they were still less than ~10 when N  =  40. As for memory usage, Geant4 was found to use more memory than the other codes. In addition, compared to that of the other codes, the memory usage of Geant4 more rapidly increased with the number of threads, reaching as high as ~74 GB when N  =  40 for the complex phantom (MRCP). It is notable that compared to that of the other codes, the memory usage of PHITS was much lower, regardless of both the complexity of the phantom and the number of threads, hardly increasing with the number of threads for the MRCP.

NaNet-10: a 10GbE network interface card for the GPU-based low-level trigger of the NA62 RICH detector.

NASA Astrophysics Data System (ADS)

Ammendola, R.; Biagioni, A.; Fiorini, M.; Frezza, O.; Lonardo, A.; Lamanna, G.; Lo Cicero, F.; Martinelli, M.; Neri, I.; Paolucci, P. S.; Pastorelli, E.; Piandani, R.; Pontisso, L.; Rossetti, D.; Simula, F.; Sozzi, M.; Tosoratto, L.; Vicini, P.

2016-03-01

A GPU-based low level (L0) trigger is currently integrated in the experimental setup of the RICH detector of the NA62 experiment to assess the feasibility of building more refined physics-related trigger primitives and thus improve the trigger discriminating power. To ensure the real-time operation of the system, a dedicated data transport mechanism has been implemented: an FPGA-based Network Interface Card (NaNet-10) receives data from detectors and forwards them with low, predictable latency to the memory of the GPU performing the trigger algorithms. Results of the ring-shaped hit patterns reconstruction will be reported and discussed.

Electronic and optical properties of GaN/AlN quantum dots with adjacent threading dislocations

NASA Astrophysics Data System (ADS)

Ye, Han; Lu, Peng-Fei; Yu, Zhong-Yuan; Yao, Wen-Jie; Chen, Zhi-Hui; Jia, Bo-Yong; Liu, Yu-Min

2010-04-01

We present a theory to simulate a coherent GaN QD with an adjacent pure edge threading dislocation by using a finite element method. The piezoelectric effects and the strain modified band edges are investigated in the framework of multi-band k · p theory to calculate the electron and the heavy hole energy levels. The linear optical absorption coefficients corresponding to the interband ground state transition are obtained via the density matrix approach and perturbation expansion method. The results indicate that the strain distribution of the threading dislocation affects the electronic structure. Moreover, the ground state transition behaviour is also influenced by the position of the adjacent threading dislocation.

The force on the flex: Global parallelism and portability

NASA Technical Reports Server (NTRS)

Jordan, H. F.

1986-01-01

A parallel programming methodology, called the force, supports the construction of programs to be executed in parallel by an unspecified, but potentially large, number of processes. The methodology was originally developed on a pipelined, shared memory multiprocessor, the Denelcor HEP, and embodies the primitive operations of the force in a set of macros which expand into multiprocessor Fortran code. A small set of primitives is sufficient to write large parallel programs, and the system has been used to produce 10,000 line programs in computational fluid dynamics. The level of complexity of the force primitives is intermediate. It is high enough to mask detailed architectural differences between multiprocessors but low enough to give the user control over performance. The system is being ported to a medium scale multiprocessor, the Flex/32, which is a 20 processor system with a mixture of shared and local memory. Memory organization and the type of processor synchronization supported by the hardware on the two machines lead to some differences in efficient implementations of the force primitives, but the user interface remains the same. An initial implementation was done by retargeting the macros to Flexible Computer Corporation's ConCurrent C language. Subsequently, the macros were caused to directly produce the system calls which form the basis for ConCurrent C. The implementation of the Fortran based system is in step with Flexible Computer Corporations's implementation of a Fortran system in the parallel environment.

Determining robot actions for tasks requiring sensor interaction

NASA Technical Reports Server (NTRS)

Budenske, John; Gini, Maria

1989-01-01

The performance of non-trivial tasks by a mobile robot has been a long term objective of robotic research. One of the major stumbling blocks to this goal is the conversion of the high-level planning goals and commands into the actuator and sensor processing controls. In order for a mobile robot to accomplish a non-trivial task, the task must be described in terms of primitive actions of the robot's actuators. Most non-trivial tasks require the robot to interact with its environment; thus necessitating coordination of sensor processing and actuator control to accomplish the task. The main contention is that the transformation from the high level description of the task to the primitive actions should be performed primarily at execution time, when knowledge about the environment can be obtained through sensors. It is proposed to produce the detailed plan of primitive actions by using a collection of low-level planning components that contain domain specific knowledge and knowledge about the available sensors, actuators, and sensor/actuator processing. This collection will perform signal and control processing as well as serve as a control interface between an actual mobile robot and a high-level planning system. Previous research has shown the usefulness of high-level planning systems to plan the coordination of activities such to achieve a goal, but none have been fully applied to actual mobile robots due to the complexity of interacting with sensors and actuators. This control interface is currently being implemented on a LABMATE mobile robot connected to a SUN workstation and will be developed such to enable the LABMATE to perform non-trivial, sensor-intensive tasks as specified by a planning system.

Role of auxin during intercellular infection of Discaria trinervis by Frankia

PubMed Central

Imanishi, Leandro; Perrine-Walker, Francine M.; Ndour, Adama; Vayssières, Alice; Conejero, Genevieve; Lucas, Mikaël; Champion, Antony; Laplaze, Laurent; Wall, Luis; Svistoonoff, Sergio

2014-01-01

Nitrogen-fixing nodules induced by Frankia in the actinorhizal plant Discaria trinervis result from a primitive intercellular root invasion pathway that does not involve root hair deformation and infection threads. Here, we analyzed the role of auxin in this intercellular infection pathway at the molecular level and compared it with our previous work in the intracellular infected actinorhizal plant Casuarina glauca. Immunolocalisation experiments showed that auxin accumulated in Frankia-infected cells in both systems. We then characterized the expression of auxin transporters in D. trinervis nodules. No activation of the heterologous CgAUX1 promoter was detected in infected cells in D. trinervis. These results were confirmed with the endogenous D. trinervis gene, DtAUX1. However, DtAUX1 was expressed in the nodule meristem. Consistently, transgenic D. trinervis plants containing the auxin response marker DR5:VENUS showed expression of the reporter gene in the meristem. Immunolocalisation experiments using an antibody against the auxin efflux carrier PIN1, revealed the presence of this transporter in the plasma membrane of infected cells. Finally, we used in silico cellular models to analyse auxin fluxes in D. trinervis nodules. Our results point to the existence of divergent roles of auxin in intercellularly- and intracellularly-infected actinorhizal plants, an ancestral infection pathways leading to root nodule symbioses. PMID:25191330

Tuning orb spider glycoprotein glue performance to habitat humidity.

PubMed

Opell, Brent D; Jain, Dharamdeep; Dhinojwala, Ali; Blackledge, Todd A

2018-03-26

Orb-weaving spiders use adhesive threads to delay the escape of insects from their webs until the spiders can locate and subdue the insects. These viscous threads are spun as paired flagelliform axial fibers coated by a cylinder of solution derived from the aggregate glands. As low molecular mass compounds (LMMCs) in the aggregate solution attract atmospheric moisture, the enlarging cylinder becomes unstable and divides into droplets. Within each droplet an adhesive glycoprotein core condenses. The plasticity and axial line extensibility of the glycoproteins are maintained by hygroscopic LMMCs. These compounds cause droplet volume to track changes in humidity and glycoprotein viscosity to vary approximately 1000-fold over the course of a day. Natural selection has tuned the performance of glycoprotein cores to the humidity of a species' foraging environment by altering the composition of its LMMCs. Thus, species from low-humidity habits have more hygroscopic threads than those from humid forests. However, at their respective foraging humidities, these species' glycoproteins have remarkably similar viscosities, ensuring optimal droplet adhesion by balancing glycoprotein adhesion and cohesion. Optimal viscosity is also essential for integrating the adhesion force of multiple droplets. As force is transferred to a thread's support line, extending droplets draw it into a parabolic configuration, implementing a suspension bridge mechanism that sums the adhesive force generated over the thread span. Thus, viscous capture threads extend an orb spider's phenotype as a highly integrated complex of large proteins and small molecules that function as a self-assembling, highly tuned, environmentally responsive, adhesive biomaterial. Understanding the synergistic role of chemistry and design in spider adhesives, particularly the ability to stick in wet conditions, provides insight in designing synthetic adhesives for biomedical applications. © 2018. Published by The Company of Biologists Ltd.

HMMerThread: detecting remote, functional conserved domains in entire genomes by combining relaxed sequence-database searches with fold recognition.

PubMed

Bradshaw, Charles Richard; Surendranath, Vineeth; Henschel, Robert; Mueller, Matthias Stefan; Habermann, Bianca Hermine

2011-03-10

Conserved domains in proteins are one of the major sources of functional information for experimental design and genome-level annotation. Though search tools for conserved domain databases such as Hidden Markov Models (HMMs) are sensitive in detecting conserved domains in proteins when they share sufficient sequence similarity, they tend to miss more divergent family members, as they lack a reliable statistical framework for the detection of low sequence similarity. We have developed a greatly improved HMMerThread algorithm that can detect remotely conserved domains in highly divergent sequences. HMMerThread combines relaxed conserved domain searches with fold recognition to eliminate false positive, sequence-based identifications. With an accuracy of 90%, our software is able to automatically predict highly divergent members of conserved domain families with an associated 3-dimensional structure. We give additional confidence to our predictions by validation across species. We have run HMMerThread searches on eight proteomes including human and present a rich resource of remotely conserved domains, which adds significantly to the functional annotation of entire proteomes. We find ∼4500 cross-species validated, remotely conserved domain predictions in the human proteome alone. As an example, we find a DNA-binding domain in the C-terminal part of the A-kinase anchor protein 10 (AKAP10), a PKA adaptor that has been implicated in cardiac arrhythmias and premature cardiac death, which upon stress likely translocates from mitochondria to the nucleus/nucleolus. Based on our prediction, we propose that with this HLH-domain, AKAP10 is involved in the transcriptional control of stress response. Further remotely conserved domains we discuss are examples from areas such as sporulation, chromosome segregation and signalling during immune response. The HMMerThread algorithm is able to automatically detect the presence of remotely conserved domains in proteins based on weak sequence similarity. Our predictions open up new avenues for biological and medical studies. Genome-wide HMMerThread domains are available at http://vm1-hmmerthread.age.mpg.de.

HMMerThread: Detecting Remote, Functional Conserved Domains in Entire Genomes by Combining Relaxed Sequence-Database Searches with Fold Recognition

PubMed Central

Bradshaw, Charles Richard; Surendranath, Vineeth; Henschel, Robert; Mueller, Matthias Stefan; Habermann, Bianca Hermine

2011-01-01

Conserved domains in proteins are one of the major sources of functional information for experimental design and genome-level annotation. Though search tools for conserved domain databases such as Hidden Markov Models (HMMs) are sensitive in detecting conserved domains in proteins when they share sufficient sequence similarity, they tend to miss more divergent family members, as they lack a reliable statistical framework for the detection of low sequence similarity. We have developed a greatly improved HMMerThread algorithm that can detect remotely conserved domains in highly divergent sequences. HMMerThread combines relaxed conserved domain searches with fold recognition to eliminate false positive, sequence-based identifications. With an accuracy of 90%, our software is able to automatically predict highly divergent members of conserved domain families with an associated 3-dimensional structure. We give additional confidence to our predictions by validation across species. We have run HMMerThread searches on eight proteomes including human and present a rich resource of remotely conserved domains, which adds significantly to the functional annotation of entire proteomes. We find ∼4500 cross-species validated, remotely conserved domain predictions in the human proteome alone. As an example, we find a DNA-binding domain in the C-terminal part of the A-kinase anchor protein 10 (AKAP10), a PKA adaptor that has been implicated in cardiac arrhythmias and premature cardiac death, which upon stress likely translocates from mitochondria to the nucleus/nucleolus. Based on our prediction, we propose that with this HLH-domain, AKAP10 is involved in the transcriptional control of stress response. Further remotely conserved domains we discuss are examples from areas such as sporulation, chromosome segregation and signalling during immune response. The HMMerThread algorithm is able to automatically detect the presence of remotely conserved domains in proteins based on weak sequence similarity. Our predictions open up new avenues for biological and medical studies. Genome-wide HMMerThread domains are available at http://vm1-hmmerthread.age.mpg.de. PMID:21423752

78 FR 44526 - Steel Threaded Rod From India and Thailand: Initiation of Antidumping Duty Investigations

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-24

... penetration; underselling and price depression or suppression; lost sales and revenues; low capacity... calculated export price (``EP'') based on lost U.S. sales and offers for sale for major types of steel... calculated EP based on lost U.S. sales and offers for sale for major types of steel threaded rod for delivery...

Low backlash direct drive actuator

DOEpatents

Kuklo, T.C.

1994-10-25

A low backlash direct drive actuator is described which comprises a motor such as a stepper motor having at least 200 steps per revolution; a two part hub assembly comprising a drive hub coaxially attached to the shaft of the motor and having a plurality of drive pins; a driven hub having a plurality of bores in one end thereof in alignment with the drive pins in the drive hub and a threaded shaft coaxially mounted in an opposite end of the driven hub; and a housing having a central bore therein into which are fitted the drive hub and driven hub, the housing having a motor mount on one end thereof to which is mounted the stepper motor, and a closed end portion with a threaded opening therein coaxial with the central bore in the housing and receiving therein the threaded shaft attached to the driven hub. Limit switches mounted to the housing cooperate with an enlarged lip on the driven hub to limit the lateral travel of the driven hub in the housing, which also acts to limit the lateral travel of the threaded shaft which functions as a lead screw. 10 figs.

Towards Resonant-State THz Laser Based on Strained p-Ge and SiGe QW Structures

DTIC Science & Technology

2006-07-01

used. The relaxed compositionally graded Si1-xGex/Si(001) buffer layer with low threading dislocations density have been grown by chemical vapour ...observe in absorption experiments. 5. Intracenter optical transitions between hydrogenic levels in doped silicon, germanium, and gallium arsenid [P...34, b. Critical magnetic field Hc vs valence band splitting Δ. Lines show the calculated Hc(Δ) dependence. 14. The gallium -doped Ge crystals with

Learning multivariate distributions by competitive assembly of marginals.

PubMed

Sánchez-Vega, Francisco; Younes, Laurent; Geman, Donald

2013-02-01

We present a new framework for learning high-dimensional multivariate probability distributions from estimated marginals. The approach is motivated by compositional models and Bayesian networks, and designed to adapt to small sample sizes. We start with a large, overlapping set of elementary statistical building blocks, or "primitives," which are low-dimensional marginal distributions learned from data. Each variable may appear in many primitives. Subsets of primitives are combined in a Lego-like fashion to construct a probabilistic graphical model; only a small fraction of the primitives will participate in any valid construction. Since primitives can be precomputed, parameter estimation and structure search are separated. Model complexity is controlled by strong biases; we adapt the primitives to the amount of training data and impose rules which restrict the merging of them into allowable compositions. The likelihood of the data decomposes into a sum of local gains, one for each primitive in the final structure. We focus on a specific subclass of networks which are binary forests. Structure optimization corresponds to an integer linear program and the maximizing composition can be computed for reasonably large numbers of variables. Performance is evaluated using both synthetic data and real datasets from natural language processing and computational biology.

THREAD: A programming environment for interactive planning-level robotics applications

NASA Technical Reports Server (NTRS)

Beahan, John J., Jr.

1989-01-01

THREAD programming language, which was developed to meet the needs of researchers in developing robotics applications that perform such tasks as grasp, trajectory design, sensor data analysis, and interfacing with external subsystems in order to perform servo-level control of manipulators and real time sensing is discussed. The philosophy behind THREAD, the issues which entered into its design, and the features of the language are discussed from the viewpoint of researchers who want to develop algorithms in a simulation environment, and from those who want to implement physical robotics systems. The detailed functions of the many complex robotics algorithms and tools which are part of the language are not explained, but an overall impression of their capability is given.

Efficient methods for implementation of multi-level nonrigid mass-preserving image registration on GPUs and multi-threaded CPUs.

PubMed

Ellingwood, Nathan D; Yin, Youbing; Smith, Matthew; Lin, Ching-Long

2016-04-01

Faster and more accurate methods for registration of images are important for research involved in conducting population-based studies that utilize medical imaging, as well as improvements for use in clinical applications. We present a novel computation- and memory-efficient multi-level method on graphics processing units (GPU) for performing registration of two computed tomography (CT) volumetric lung images. We developed a computation- and memory-efficient Diffeomorphic Multi-level B-Spline Transform Composite (DMTC) method to implement nonrigid mass-preserving registration of two CT lung images on GPU. The framework consists of a hierarchy of B-Spline control grids of increasing resolution. A similarity criterion known as the sum of squared tissue volume difference (SSTVD) was adopted to preserve lung tissue mass. The use of SSTVD consists of the calculation of the tissue volume, the Jacobian, and their derivatives, which makes its implementation on GPU challenging due to memory constraints. The use of the DMTC method enabled reduced computation and memory storage of variables with minimal communication between GPU and Central Processing Unit (CPU) due to ability to pre-compute values. The method was assessed on six healthy human subjects. Resultant GPU-generated displacement fields were compared against the previously validated CPU counterpart fields, showing good agreement with an average normalized root mean square error (nRMS) of 0.044±0.015. Runtime and performance speedup are compared between single-threaded CPU, multi-threaded CPU, and GPU algorithms. Best performance speedup occurs at the highest resolution in the GPU implementation for the SSTVD cost and cost gradient computations, with a speedup of 112 times that of the single-threaded CPU version and 11 times over the twelve-threaded version when considering average time per iteration using a Nvidia Tesla K20X GPU. The proposed GPU-based DMTC method outperforms its multi-threaded CPU version in terms of runtime. Total registration time reduced runtime to 2.9min on the GPU version, compared to 12.8min on twelve-threaded CPU version and 112.5min on a single-threaded CPU. Furthermore, the GPU implementation discussed in this work can be adapted for use of other cost functions that require calculation of the first derivatives. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

A Generalized-Compliant-Motion Primitive

NASA Technical Reports Server (NTRS)

Backes, Paul G.

1993-01-01

Computer program bridges gap between planning and execution of compliant robotic motions developed and installed in control system of telerobot. Called "generalized-compliant-motion primitive," one of several task-execution-primitive computer programs, which receives commands from higher-level task-planning programs and executes commands by generating required trajectories and applying appropriate control laws. Program comprises four parts corresponding to nominal motion, compliant motion, ending motion, and monitoring. Written in C language.

Research of thread rolling on difficult-to-cut material workpieces

NASA Astrophysics Data System (ADS)

Popov, A. Yu; Bugay, I. A.; Nazarov, P. V.; Evdokimova, O. P.; Popov, P. E.; Vasilyev, E. V.

2018-01-01

In medicine production Ti-6Al-4V Grade 5 alloys are used. One of the most important tasks is to increase the strength of the products and decrease in value. The possibility to roll special thread on Ti-6Al-4V Grade 5 alloy workpiece on 2-roller thread rolling machine has been studied. This is wrought alloy, treatment of which in cold condition causes difficulties due to low plasticity. To obtain Ti-6Al-4V Grade 5 alloy product with thread by rolling is rather difficult. This is due to large axial workpiece displacements resulting from large alloy resistance to cold plastic deformation. The provision of adequate kinematics requires experimental researches and the selection of modes - speed of rolling and pressure on the movable roller. The purpose of the work is to determine the optimal modes for rolling thread on titanium alloy workpiece. It has been stated that, after rolling, the product strength has increased up to 30%. As a result of the work, the unit has been made and recommendations to choose the optimal rolling process modes have been offered.

Software Defined Radio with Parallelized Software Architecture

NASA Technical Reports Server (NTRS)

Heckler, Greg

2013-01-01

This software implements software-defined radio procession over multicore, multi-CPU systems in a way that maximizes the use of CPU resources in the system. The software treats each processing step in either a communications or navigation modulator or demodulator system as an independent, threaded block. Each threaded block is defined with a programmable number of input or output buffers; these buffers are implemented using POSIX pipes. In addition, each threaded block is assigned a unique thread upon block installation. A modulator or demodulator system is built by assembly of the threaded blocks into a flow graph, which assembles the processing blocks to accomplish the desired signal processing. This software architecture allows the software to scale effortlessly between single CPU/single-core computers or multi-CPU/multi-core computers without recompilation. NASA spaceflight and ground communications systems currently rely exclusively on ASICs or FPGAs. This software allows low- and medium-bandwidth (100 bps to approx.50 Mbps) software defined radios to be designed and implemented solely in C/C++ software, while lowering development costs and facilitating reuse and extensibility.

Software Defined Radio with Parallelized Software Architecture

NASA Technical Reports Server (NTRS)

Heckler, Greg

2013-01-01

This software implements software-defined radio procession over multi-core, multi-CPU systems in a way that maximizes the use of CPU resources in the system. The software treats each processing step in either a communications or navigation modulator or demodulator system as an independent, threaded block. Each threaded block is defined with a programmable number of input or output buffers; these buffers are implemented using POSIX pipes. In addition, each threaded block is assigned a unique thread upon block installation. A modulator or demodulator system is built by assembly of the threaded blocks into a flow graph, which assembles the processing blocks to accomplish the desired signal processing. This software architecture allows the software to scale effortlessly between single CPU/single-core computers or multi-CPU/multi-core computers without recompilation. NASA spaceflight and ground communications systems currently rely exclusively on ASICs or FPGAs. This software allows low- and medium-bandwidth (100 bps to .50 Mbps) software defined radios to be designed and implemented solely in C/C++ software, while lowering development costs and facilitating reuse and extensibility.

The fall of a viscous thread onto a moving surface: a ‘fluid-mechanical sewing machine’

NASA Astrophysics Data System (ADS)

Chiu-Webster, S.; Lister, J. R.

2006-12-01

A viscous thread falling onto a steadily moving horizontal belt shows a surprisingly complex range of behaviour in experiments. Low belt speeds produce coiling, as might be expected from the behaviour of a thread falling onto a stationary surface. High belt speeds produce a steady thread, whose shape is predicted well by theory developed to describe a stretching viscous catenary with surface tension and inertia. Intermediate belt speeds show several novel modes of oscillation, which lay down a wide variety of patterns on the belt. The patterns include meanders, side kicks, slanted loops, braiding, figures-of-eight, Ws, and also period-doubled versions of figures-of-eight, meanders and coiling. The experimental boundary between steady and unsteady behaviour occurs at a slightly lower belt speed than the loss of the steady solution for a stretching catenary.

GPU-Acceleration of Sequence Homology Searches with Database Subsequence Clustering.

PubMed

Suzuki, Shuji; Kakuta, Masanori; Ishida, Takashi; Akiyama, Yutaka

2016-01-01

Sequence homology searches are used in various fields and require large amounts of computation time, especially for metagenomic analysis, owing to the large number of queries and the database size. To accelerate computing analyses, graphics processing units (GPUs) are widely used as a low-cost, high-performance computing platform. Therefore, we mapped the time-consuming steps involved in GHOSTZ, which is a state-of-the-art homology search algorithm for protein sequences, onto a GPU and implemented it as GHOSTZ-GPU. In addition, we optimized memory access for GPU calculations and for communication between the CPU and GPU. As per results of the evaluation test involving metagenomic data, GHOSTZ-GPU with 12 CPU threads and 1 GPU was approximately 3.0- to 4.1-fold faster than GHOSTZ with 12 CPU threads. Moreover, GHOSTZ-GPU with 12 CPU threads and 3 GPUs was approximately 5.8- to 7.7-fold faster than GHOSTZ with 12 CPU threads.

Numerical simulations of a transverse indirect circulation and low-level jet in the exit region of an upper-level jet

NASA Technical Reports Server (NTRS)

Brill, K. F.; Uccellini, L. W.; Burkhart, R. P.; Warner, T. T.; Anthes, R. A.

1985-01-01

A numerical study was performed of a severe weather event (tornado) which occurred on May 10, 1973 in the Ohio region. The situation was modeled with a primitive equation mesoscale dynamic formulation. Account was taken of precipitation, the planetary boundary layer parameters as bulk quantities, the vertical pressure gradient, and lateral boundary conditions based on radiosonde data. Two 12-hr simulations, adiabatic and nondivergent, respectively, were analyzed for relationships between upper and lower level jets. In the adiabatic formulation, a transverse circulation with a low level jet formed at the exit region of the upper level jet. The nondivergent situation led to similar, but weaker, phenomena. Both forms suggest that indirect circulation in the exit zone of an upper level jet is strongly influenced by the initial structure of the jet.

FPGA-Based Multimodal Embedded Sensor System Integrating Low- and Mid-Level Vision

PubMed Central

Botella, Guillermo; Martín H., José Antonio; Santos, Matilde; Meyer-Baese, Uwe

2011-01-01

Motion estimation is a low-level vision task that is especially relevant due to its wide range of applications in the real world. Many of the best motion estimation algorithms include some of the features that are found in mammalians, which would demand huge computational resources and therefore are not usually available in real-time. In this paper we present a novel bioinspired sensor based on the synergy between optical flow and orthogonal variant moments. The bioinspired sensor has been designed for Very Large Scale Integration (VLSI) using properties of the mammalian cortical motion pathway. This sensor combines low-level primitives (optical flow and image moments) in order to produce a mid-level vision abstraction layer. The results are described trough experiments showing the validity of the proposed system and an analysis of the computational resources and performance of the applied algorithms. PMID:22164069

FPGA-based multimodal embedded sensor system integrating low- and mid-level vision.

PubMed

Botella, Guillermo; Martín H, José Antonio; Santos, Matilde; Meyer-Baese, Uwe

2011-01-01

Motion estimation is a low-level vision task that is especially relevant due to its wide range of applications in the real world. Many of the best motion estimation algorithms include some of the features that are found in mammalians, which would demand huge computational resources and therefore are not usually available in real-time. In this paper we present a novel bioinspired sensor based on the synergy between optical flow and orthogonal variant moments. The bioinspired sensor has been designed for Very Large Scale Integration (VLSI) using properties of the mammalian cortical motion pathway. This sensor combines low-level primitives (optical flow and image moments) in order to produce a mid-level vision abstraction layer. The results are described trough experiments showing the validity of the proposed system and an analysis of the computational resources and performance of the applied algorithms.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bonachea, Dan; Hargrove, P.

GASNet is a language-independent, low-level networking layer that provides network-independent, high-performance communication primitives tailored for implementing parallel global address space SPMD languages and libraries such as UPC, UPC++, Co-Array Fortran, Legion, Chapel, and many others. The interface is primarily intended as a compilation target and for use by runtime library writers (as opposed to end users), and the primary goals are high performance, interface portability, and expressiveness. GASNet stands for "Global-Address Space Networking".

Metabolic studies of mammalian cells by 31P-NMR using a continuous perfusion technique.

PubMed

Knop, R H; Chen, C W; Mitchell, J B; Russo, A; McPherson, S; Cohen, J S

1984-07-20

Levels of ATP and Pi in metabolically active Chinese hamster lung fibroblasts were monitored noninvasively by 31P-NMR over many hours and under a variety of conditions. The cells were embedded in a matrix of agarose gel in the form of fine threads which were continuously perfused in a standard NMR tube. The small diameter of the thread allows rapid diffusion of metabolites and drugs into the cells. The changes in ATP and Pi levels were followed as a function of time in response to perfusion with a glucose-containing medium, with isotonic saline and with a medium containing 2,4-dinitrophenol, an uncoupler of oxidative phosphorylation. This gel-thread perfusion method should enable routine NMR studies of cellular metabolism, and may have other potential biological applications.

Very Massive Stars in the Primitive Galaxy, IZw 18

NASA Technical Reports Server (NTRS)

Heap, Sara

2012-01-01

IZw 18 is a local blue, compact dwarf galaxy that meets the requirements for a primitive galaxy: low halo mass greater than 10(exp 9) Msun, strong photoionizing radiation, no galactic outflow, and very low metallicity,log(O/H)+12=7.2. We will describe the properties and evolutionary status of very massive stars in IZw 18, based on UV photometry of individual stars in I Zw 18 and analysis of unresolved ultraviolet spectra of IZw 18-NW obtained with HST.

Factors affecting the pullout strength of cancellous bone screws.

PubMed

Chapman, J R; Harrington, R M; Lee, K M; Anderson, P A; Tencer, A F; Kowalski, D

1996-08-01

Screws placed into cancellous bone in orthopedic surgical applications, such as fixation of fractures of the femoral neck or the lumbar spine, can be subjected to high loads. Screw pullout is a possibility, especially if low density osteoporotic bone is encountered. The overall goal of this study was to determine how screw thread geometry, tapping, and cannulation affect the holding power of screws in cancellous bone and determine whether current designs achieve maximum purchase strength. Twelve types of commercially available cannulated and noncannulated cancellous bone screws were tested for pullout strength in rigid unicellular polyurethane foams of apparent densities and shear strengths within the range reported for human cancellous bone. The experimentally derived pullout strength was compared to a predicted shear failure force of the internal threads formed in the polyurethane foam. Screws embedded in porous materials pullout by shearing the internal threads in the porous material. Experimental pullout force was highly correlated to the predicted shear failure force (slope = 1.05, R2 = 0.947) demonstrating that it is controlled by the major diameter of the screw, the length of engagement of the thread, the shear strength of the material into which the screw is embedded, and a thread shape factor (TSF) which accounts for screw thread depth and pitch. The average TSF for cannulated screws was 17 percent lower than that of noncannulated cancellous screws, and the pullout force was correspondingly less. Increasing the TSF, a result of decreasing thread pitch or increasing thread depth, increases screw purchase strength in porous materials. Tapping was found to reduce pullout force by an average of 8 percent compared with nontapped holes (p = 0.0001). Tapping in porous materials decreases screw pullout strength because the removal of material by the tap enlarges hole volume by an average of 27 percent, in effect decreasing the depth and shear area of the internal threads in the porous material.

Developing eThread pipeline using SAGA-pilot abstraction for large-scale structural bioinformatics.

PubMed

Ragothaman, Anjani; Boddu, Sairam Chowdary; Kim, Nayong; Feinstein, Wei; Brylinski, Michal; Jha, Shantenu; Kim, Joohyun

2014-01-01

While most of computational annotation approaches are sequence-based, threading methods are becoming increasingly attractive because of predicted structural information that could uncover the underlying function. However, threading tools are generally compute-intensive and the number of protein sequences from even small genomes such as prokaryotes is large typically containing many thousands, prohibiting their application as a genome-wide structural systems biology tool. To leverage its utility, we have developed a pipeline for eThread--a meta-threading protein structure modeling tool, that can use computational resources efficiently and effectively. We employ a pilot-based approach that supports seamless data and task-level parallelism and manages large variation in workload and computational requirements. Our scalable pipeline is deployed on Amazon EC2 and can efficiently select resources based upon task requirements. We present runtime analysis to characterize computational complexity of eThread and EC2 infrastructure. Based on results, we suggest a pathway to an optimized solution with respect to metrics such as time-to-solution or cost-to-solution. Our eThread pipeline can scale to support a large number of sequences and is expected to be a viable solution for genome-scale structural bioinformatics and structure-based annotation, particularly, amenable for small genomes such as prokaryotes. The developed pipeline is easily extensible to other types of distributed cyberinfrastructure.

CRUSER News. Issue 30, Aug 2013

DTIC Science & Technology

2013-08-01

Versatile Low Cost Tactical SUAS by Dr. Richard Guiler, Physical Sciences Inc. • Small Unmanned Aircraft System ( SUAS )/Unattended Ground Sensor...NPS faculty JIFX 13-4 was held last week and included several different planned experiments in the unmanned systems /robot- ics thread. One of the many... planned experiments for the unmanned systems / robotics thread. • Tactical Operations for Multiple Swarm UAVs by Dr Timothy Chung, NPS • ងlb

Power/Performance Trade-offs of Small Batched LU Based Solvers on GPUs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Villa, Oreste; Fatica, Massimiliano; Gawande, Nitin A.

In this paper we propose and analyze a set of batched linear solvers for small matrices on Graphic Processing Units (GPUs), evaluating the various alternatives depending on the size of the systems to solve. We discuss three different solutions that operate with different level of parallelization and GPU features. The first, exploiting the CUBLAS library, manages matrices of size up to 32x32 and employs Warp level (one matrix, one Warp) parallelism and shared memory. The second works at Thread-block level parallelism (one matrix, one Thread-block), still exploiting shared memory but managing matrices up to 76x76. The third is Thread levelmore » parallel (one matrix, one thread) and can reach sizes up to 128x128, but it does not exploit shared memory and only relies on the high memory bandwidth of the GPU. The first and second solution only support partial pivoting, the third one easily supports partial and full pivoting, making it attractive to problems that require greater numerical stability. We analyze the trade-offs in terms of performance and power consumption as function of the size of the linear systems that are simultaneously solved. We execute the three implementations on a Tesla M2090 (Fermi) and on a Tesla K20 (Kepler).« less

Automatic building of a web-like structure based on thermoplastic adhesive.

PubMed

Leach, Derek; Wang, Liyu; Reusser, Dorothea; Iida, Fumiya

2014-09-01

Animals build structures to extend their control over certain aspects of the environment; e.g., orb-weaver spiders build webs to capture prey, etc. Inspired by this behaviour of animals, we attempt to develop robotics technology that allows a robot to automatically builds structures to help it accomplish certain tasks. In this paper we show automatic building of a web-like structure with a robot arm based on thermoplastic adhesive (TPA) material. The material properties of TPA, such as elasticity, adhesiveness, and low melting temperature, make it possible for a robot to form threads across an open space by an extrusion-drawing process and then combine several of these threads into a web-like structure. The problems addressed here are discovering which parameters determine the thickness of a thread and determining how web-like structures may be used for certain tasks. We first present a model for the extrusion and the drawing of TPA threads which also includes the temperature-dependent material properties. The model verification result shows that the increasing relative surface area of the TPA thread as it is drawn thinner increases the heat loss of the thread, and that by controlling how quickly the thread is drawn, a range of diameters can be achieved from 0.2-0.75 mm. We then present a method based on a generalized nonlinear finite element truss model. The model was validated and could predict the deformation of various web-like structures when payloads are added. At the end, we demonstrate automatic building of a web-like structure for payload bearing.

Biomechanical evaluation of dental implants with three different designs: Removal torque and resonance frequency analysis in rabbits.

PubMed

Gehrke, Sergio Alexandre; Marin, Giovanni Wiel

2015-05-01

The objective of this study was to investigate the effect of implant design on stability and resistance to reverse torque in the tibia of rabbits. Three test groups were prepared using the different characteristics of each implant model: square threads with progressive depth to the apex, a cervical portion without threads and a self-tapping system that is quite pronounced and aggressive (Group 1); triangular threads with flat tips with increasing thread depth from the cervical portion to the apex and a small self-tapping portion with a short thread pitch (Group 2); long thread pitch, progressive thread depth, an apical area with a small self-tapping portion (Group 3). For the two last groups, a final single-use drill was provided for each implant. Nine rabbits received 54 conical implants with a same surface treatment. The resonance frequency was analysed four times (0, 6, 8 and 12 weeks), and removal torque values were measured at three time intervals after the implantations (6, 8 and 12 weeks). In comparing the implant stability quotient at the four time points, highly significant statistic differences were found (p = 1.29(-10)). The reverse torque at the three time points was also significantly different among the groups (p = 0.00015). The implants of Group 2, with seemingly less aggressive design, more quickly reached high values of stability and removal torque. Under the limitations of this study, however, it is possible that in cases in which there may be low osseointegration response, the implant design should be evaluated. Copyright © 2014 Elsevier GmbH. All rights reserved.

Wallops Ship Surveillance System

NASA Technical Reports Server (NTRS)

Smith, Donna C.

2011-01-01

Approved as a Wallops control center backup system, the Wallops Ship Surveillance Software is a day-of-launch risk analysis tool for spaceport activities. The system calculates impact probabilities and displays ship locations relative to boundary lines. It enables rapid analysis of possible flight paths to preclude the need to cancel launches and allow execution of launches in a timely manner. Its design is based on low-cost, large-customer- base elements including personal computers, the Windows operating system, C/C++ object-oriented software, and network interfaces. In conformance with the NASA software safety standard, the system is designed to ensure that it does not falsely report a safe-for-launch condition. To improve the current ship surveillance method, the system is designed to prevent delay of launch under a safe-for-launch condition. A single workstation is designated the controller of the official ship information and the official risk analysis. Copies of this information are shared with other networked workstations. The program design is divided into five subsystems areas: 1. Communication Link -- threads that control the networking of workstations; 2. Contact List -- a thread that controls a list of protected item (ocean vessel) information; 3. Hazard List -- threads that control a list of hazardous item (debris) information and associated risk calculation information; 4. Display -- threads that control operator inputs and screen display outputs; and 5. Archive -- a thread that controls archive file read and write access. Currently, most of the hazard list thread and parts of other threads are being reused as part of a new ship surveillance system, under the SureTrak project.

Efficient Strategies for Active Interface-Level Network Topology Discovery

DTIC Science & Technology

2013-09-01

Network Information Centre API Application Programming Interface APNIC Asia-Pacific Network Information Centre ARIN American Registry for Internet Numbers...very convenient Application Programming Interface ( API ) for easy primitive implementation. Ark’s API facilitates easy development and rapid...prototyping – important attributes as the char- acteristics of our primitives evolve. The API allows a high-level of abstraction, which in turn leads to rapid

A knittable fiber-shaped supercapacitor based on natural cotton thread for wearable electronics

NASA Astrophysics Data System (ADS)

Zhou, Qianlong; Jia, Chunyang; Ye, Xingke; Tang, Zhonghua; Wan, Zhongquan

2016-09-01

At present, the topic of building high-performance, miniaturized and mechanically flexible energy storage modules which can be directly integrated into textile based wearable electronics is a hotspot in the wearable technology field. In this paper, we reported a highly flexible fiber-shaped electrode fabricated through a one-step convenient hydrothermal process. The prepared graphene hydrogels/multi-walled carbon nanotubes-cotton thread derived from natural cotton thread is electrochemically active and mechanically strong. Fiber-shaped supercapacitor based on the prepared fiber electrodes and polyvinyl alcohol-H3PO4 gel electrolyte exhibits good capacitive performance (97.73 μF cm-1 at scan rate of 2 mV s-1), long cycle life (95.51% capacitance retention after 8000 charge-discharge cycles) and considerable stability (90.75% capacitance retention after 500 continuous bending cycles). Due to its good mechanical and electrochemical properties, the graphene hydrogels/multi-walled carbon nanotubes-cotton thread based all-solid fiber-shaped supercapacitor can be directly knitted into fabrics and maintain its original capacitive performance. Such a low-cost textile thread based versatile energy storage device may hold great potential for future wearable electronics applications.

21. View of endlift slide on pedestal and threaded shaft ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

21. View of end-lift slide on pedestal and threaded shaft with level gears. Curved deck joint at underside of roadway deck is seen, as well as submarine electrical cables resting on the masonry pier. (Nov. 30, 1988) - University Heights Bridge, Spanning Harlem River at 207th Street & West Harlem Road, New York County, NY

Shallow Population Genetic Structures of Thread-sail Filefish (Stephanolepis cirrhifer) Populations from Korean Coastal Waters.

PubMed

Yoon, M; Park, W; Nam, Y K; Kim, D S

2012-02-01

Genetic diversities, population genetic structures and demographic histories of the thread-sail filefish Stephanolepis cirrhifer were investigated by nucleotide sequencing of 336 base pairs of the mitochondrial DNA (mtDNA) control region in 111 individuals collected from six populations in Korean coastal waters. A total of 70 haplotypes were defined by 58 variable nucleotide sites. The neighbor-joining tree of the 70 haplotypes was shallow and did not provide evidence of geographical associations. Expansion of S. cirrhifer populations began approximate 51,000 to 102,000 years before present, correlating with the period of sea level rise since the late Pleistocene glacial maximum. High levels of haplotype diversities (0.974±0.029 to 1.000±0.076) and nucleotide diversities (0.014 to 0.019), and low levels of genetic differentiation among populations inferred from pairwise population F ST values (-0.007 to 0.107), support an expansion of the S. cirrhifer population. Hierarchical analysis of molecular variance (AMOVA) revealed weak but significant genetic structures among three groups (F CT = 0.028, p<0.05), and no genetic variation within groups (0.53%; F SC = 0.005, p = 0.23). These results may help establish appropriate fishery management strategies for stocks of S. cirrhifer and related species.

Shallow Population Genetic Structures of Thread-sail Filefish (Stephanolepis cirrhifer) Populations from Korean Coastal Waters

PubMed Central

Yoon, M.; Park, W.; Nam, Y. K.; Kim, D. S.

2012-01-01

Genetic diversities, population genetic structures and demographic histories of the thread-sail filefish Stephanolepis cirrhifer were investigated by nucleotide sequencing of 336 base pairs of the mitochondrial DNA (mtDNA) control region in 111 individuals collected from six populations in Korean coastal waters. A total of 70 haplotypes were defined by 58 variable nucleotide sites. The neighbor-joining tree of the 70 haplotypes was shallow and did not provide evidence of geographical associations. Expansion of S. cirrhifer populations began approximate 51,000 to 102,000 years before present, correlating with the period of sea level rise since the late Pleistocene glacial maximum. High levels of haplotype diversities (0.974±0.029 to 1.000±0.076) and nucleotide diversities (0.014 to 0.019), and low levels of genetic differentiation among populations inferred from pairwise population FST values (−0.007 to 0.107), support an expansion of the S. cirrhifer population. Hierarchical analysis of molecular variance (AMOVA) revealed weak but significant genetic structures among three groups (FCT = 0.028, p<0.05), and no genetic variation within groups (0.53%; FSC = 0.005, p = 0.23). These results may help establish appropriate fishery management strategies for stocks of S. cirrhifer and related species. PMID:25049547

NAVFAC Ocean Thermal Energy Conversion (OTEC) Project; OTEC Technology Development Report

DTIC Science & Technology

2010-11-01

platform and CWP. It was a goal of this program to find a material that is high in abrasion resistance and low in friction for the guide layers. Figure...preferred material was a high density urethane. Urethane has very high abrasion resistance – it is often used for marine buoys, fenders, and coatings...design thread in the document. The following is a list of the top level sections in the report. EXECUTIVE SUMMARY  1  1.  INTRODUCTION  2  2

Test chamber for alpha spectrometry

DOEpatents

Larsen, Robert P.

1977-01-01

Alpha emitters for low-level radiochemical analysis by measurement of alpha spectra are positioned precisely with respect to the location of a surface-barrier detector by means of a chamber having a removable threaded planchet holder. A pedestal on the planchet holder holds a specimen in fixed engagement close to the detector. Insertion of the planchet holder establishes an O-ring seal that permits the chamber to be pumped to a desired vacuum. The detector is protected against accidental contact and resulting damage.

Dislocation related droop in InGaN/GaN light emitting diodes investigated via cathodoluminescence

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pozina, Galia; Ciechonski, Rafal; Bi, Zhaoxia

2015-12-21

Today's energy saving solutions for general illumination rely on efficient white light emitting diodes (LEDs). However, the output efficiency droop experienced in InGaN based LEDs with increasing current injection is a serious limitation factor for future development of bright white LEDs. We show using cathodoluminescence (CL) spatial mapping at different electron beam currents that threading dislocations are active as nonradiative recombination centers only at high injection conditions. At low current, the dislocations are inactive in carrier recombination due to local potentials, but these potentials are screened by carriers at higher injection levels. In CL images, this corresponds to the increasemore » of the dark contrast around dislocations with the injection (excitation) density and can be linked with droop related to the threading dislocations. Our data indicate that reduction of droop in the future efficient white LED can be achieved via a drastic reduction of the dislocation density by using, for example, bulk native substrates.« less

GPU-Acceleration of Sequence Homology Searches with Database Subsequence Clustering

PubMed Central

Suzuki, Shuji; Kakuta, Masanori; Ishida, Takashi; Akiyama, Yutaka

2016-01-01

Sequence homology searches are used in various fields and require large amounts of computation time, especially for metagenomic analysis, owing to the large number of queries and the database size. To accelerate computing analyses, graphics processing units (GPUs) are widely used as a low-cost, high-performance computing platform. Therefore, we mapped the time-consuming steps involved in GHOSTZ, which is a state-of-the-art homology search algorithm for protein sequences, onto a GPU and implemented it as GHOSTZ-GPU. In addition, we optimized memory access for GPU calculations and for communication between the CPU and GPU. As per results of the evaluation test involving metagenomic data, GHOSTZ-GPU with 12 CPU threads and 1 GPU was approximately 3.0- to 4.1-fold faster than GHOSTZ with 12 CPU threads. Moreover, GHOSTZ-GPU with 12 CPU threads and 3 GPUs was approximately 5.8- to 7.7-fold faster than GHOSTZ with 12 CPU threads. PMID:27482905

Vectorization for Molecular Dynamics on Intel Xeon Phi Corpocessors

NASA Astrophysics Data System (ADS)

Yi, Hongsuk

2014-03-01

Many modern processors are capable of exploiting data-level parallelism through the use of single instruction multiple data (SIMD) execution. The new Intel Xeon Phi coprocessor supports 512 bit vector registers for the high performance computing. In this paper, we have developed a hierarchical parallelization scheme for accelerated molecular dynamics simulations with the Terfoff potentials for covalent bond solid crystals on Intel Xeon Phi coprocessor systems. The scheme exploits multi-level parallelism computing. We combine thread-level parallelism using a tightly coupled thread-level and task-level parallelism with 512-bit vector register. The simulation results show that the parallel performance of SIMD implementations on Xeon Phi is apparently superior to their x86 CPU architecture.

Melt Inclusions Record Extreme Compositional Variability in Primitive Magmas at Mauna Loa Volcano, Hawaii

NASA Astrophysics Data System (ADS)

Kamenetsky, V. S.; Norman, M. D.; Garcia, M. O.

2002-12-01

Melt inclusions carry potentially unique information about magmatic processes and the compositional evolution of erupted lavas. Major element compositions of olivine-hosted melt inclusions in submarine tholeiitic picrites from the southwest rift zone of Mauna Loa volcano have been studied to examine the compositional variability of primitive magmas feeding the world's largest volcano. Approximately 600 naturally quenched inclusions were examined from 8 samples with 3-25 vol% olivine phenocrysts and 9-22 wt% MgO. Olivine compositions ranged from Fo91-Fo82. The inclusions show a continuous variation in FeO contents from near-magmatic values (9 to 11 wt%) in the most evolved olivines to extremely low values (3.5 to 7.0 wt%) in the most primitive olivines. This appears to reflect a complex magmatic history for these crystals involving extensive re-equlibration of melts trapped by early formed phenocrysts with their host olivine. Extreme compositional variability also characterizes incompatible elements that would not be affected by equilibration with the host olivine. Inclusions trapped in relatively primitive olivines (Fo88-91) show a large range of K2O contents (0.1 to 2.1 wt%), whereas inclusions in more evolved olivines converge on whole rock compositions with 0.3 to 0.4 wt% K2O. Similarly, TiO2/K2O, Na2O/K2O, and K2O/P2O5 ratios of inclusions in primitive olivines span a much larger range than do inclusions hosted by more evolved olivines, with TiO2/K2O ratios extending from enriched to depleted compositions (1.2 to 24.7) in primitive olivines, and converging on whole rock compositions (TiO2/K2O = 6-9) in more evolved host olivine. This points toward extreme compositional variability in melts feeding Mauna Loa, and effective mixing of these melt parcels in the shallower summit reservoir to produce the restricted range of whole rock compositions sampled by erupted lavas. Whole rock compositions, therefore provide an integrated view of melting and high-level mixing processes, whereas melt inclusions provide more detailed information about source characteristics.

Initial Kernel Timing Using a Simple PIM Performance Model

NASA Technical Reports Server (NTRS)

Katz, Daniel S.; Block, Gary L.; Springer, Paul L.; Sterling, Thomas; Brockman, Jay B.; Callahan, David

2005-01-01

This presentation will describe some initial results of paper-and-pencil studies of 4 or 5 application kernels applied to a processor-in-memory (PIM) system roughly similar to the Cascade Lightweight Processor (LWP). The application kernels are: * Linked list traversal * Sun of leaf nodes on a tree * Bitonic sort * Vector sum * Gaussian elimination The intent of this work is to guide and validate work on the Cascade project in the areas of compilers, simulators, and languages. We will first discuss the generic PIM structure. Then, we will explain the concepts needed to program a parallel PIM system (locality, threads, parcels). Next, we will present a simple PIM performance model that will be used in the remainder of the presentation. For each kernel, we will then present a set of codes, including codes for a single PIM node, and codes for multiple PIM nodes that move data to threads and move threads to data. These codes are written at a fairly low level, between assembly and C, but much closer to C than to assembly. For each code, we will present some hand-drafted timing forecasts, based on the simple PIM performance model. Finally, we will conclude by discussing what we have learned from this work, including what programming styles seem to work best, from the point-of-view of both expressiveness and performance.

Constant time worker thread allocation via configuration caching

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eichenberger, Alexandre E; O'Brien, John K. P.

Mechanisms are provided for allocating threads for execution of a parallel region of code. A request for allocation of worker threads to execute the parallel region of code is received from a master thread. Cached thread allocation information identifying prior thread allocations that have been performed for the master thread are accessed. Worker threads are allocated to the master thread based on the cached thread allocation information. The parallel region of code is executed using the allocated worker threads.

Basis set construction for molecular electronic structure theory: natural orbital and Gauss-Slater basis for smooth pseudopotentials.

PubMed

Petruzielo, F R; Toulouse, Julien; Umrigar, C J

2011-02-14

A simple yet general method for constructing basis sets for molecular electronic structure calculations is presented. These basis sets consist of atomic natural orbitals from a multiconfigurational self-consistent field calculation supplemented with primitive functions, chosen such that the asymptotics are appropriate for the potential of the system. Primitives are optimized for the homonuclear diatomic molecule to produce a balanced basis set. Two general features that facilitate this basis construction are demonstrated. First, weak coupling exists between the optimal exponents of primitives with different angular momenta. Second, the optimal primitive exponents for a chosen system depend weakly on the particular level of theory employed for optimization. The explicit case considered here is a basis set appropriate for the Burkatzki-Filippi-Dolg pseudopotentials. Since these pseudopotentials are finite at nuclei and have a Coulomb tail, the recently proposed Gauss-Slater functions are the appropriate primitives. Double- and triple-zeta bases are developed for elements hydrogen through argon. These new bases offer significant gains over the corresponding Burkatzki-Filippi-Dolg bases at various levels of theory. Using a Gaussian expansion of the basis functions, these bases can be employed in any electronic structure method. Quantum Monte Carlo provides an added benefit: expansions are unnecessary since the integrals are evaluated numerically.

Fine resolution chronology based on initial Sr-87/Sr-86

NASA Technical Reports Server (NTRS)

Stewart, B. W.; Papanastassiou, D. A.; Capo, R. C.; Wasserburg, G. J.

1993-01-01

It has been recognized that small variations in initial Sr-87/Sr-86 (Sr(sub I)), can provide a fine scale relative chronology for the chemical fractionation of materials with low Rb/Sr from parent reservoirs with high Rb/Sr. Similarly, Sr(sub I), as determined for low Rb/Sr phases in meteorites, may permit a fine resolution chronology of the recrystallization or metamorphism of planetary materials. For the establishment of a primitive Sr-87/Sr-86 chronology, it is important to search for samples with extremely low Rb/Sr for which the measured Sr-87/Sr-86 is below BABI, in which case the primitive nature of the Sr can be directly established. Using the measured Rb/Sr to calculate an initial Sr-87/Sr-86 can introduce substantial uncertainty if the Rb-Sr are disturbed. We report Sr-87/Sr-86 in plagioclase from silicate pebbles from the Vaca Muerta mesosiderite on which we have reported Sm-147-Nd-143 and Ne-142 correlations. For the purpose of cross-calibration with our previous work we have performed extensive new measurements on Angra dos Reis and on anorthite from Moore County, which have very low Rb/Sr and primitive Sr-87/Sr-86.

Screw-Thread Standards for Federal Services, 1957. Handbook H28 (1957), Part 3

DTIC Science & Technology

1957-09-01

MOUNTING THREADS PHOTOGRAPHIC EQUIPMENT THREADS ISO METRIC THREADS; MISCELLANEOUS THREADS CLASS 5 INTERFERENCE-FIT THREADS, TRIAL STANDARD WRENCH...Bibliography on measurement of pitch diameter by means of wires 60 Appendix 14. Metric screw-thread standards 61 1. ISO thread profiles...61 2. Standard series for ISO metric threads 62 3. Designations for ISO metric threads 62 Tables Page Table XII. 1.—Basic

A survey of DNA methylation across social insect species, life stages, and castes reveals abundant and caste-associated methylation in a primitively social wasp

NASA Astrophysics Data System (ADS)

Weiner, Susan A.; Galbraith, David A.; Adams, Dean C.; Valenzuela, Nicole; Noll, Fernando B.; Grozinger, Christina M.; Toth, Amy L.

2013-08-01

DNA methylation plays an important role in the epigenetic control of developmental and behavioral plasticity, with connections to the generation of striking phenotypic differences between castes (larger, reproductive queens and smaller, non-reproductive workers) in honeybees and ants. Here, we provide the first comparative investigation of caste- and life stage-associated DNA methylation in several species of bees and vespid wasps displaying different levels of social organization. Our results reveal moderate levels of DNA methylation in most bees and wasps, with no clear relationship to the level of sociality. Strikingly, primitively social Polistes dominula paper wasps show unusually high overall DNA methylation and caste-related differences in site-specific methylation. These results suggest DNA methylation may play a role in the regulation of behavioral and physiological differences in primitively social species with more flexible caste differences.

Deploy Nalu/Kokkos algorithmic infrastructure with performance benchmarking.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Domino, Stefan P.; Ananthan, Shreyas; Knaus, Robert C.

The former Nalu interior heterogeneous algorithm design, which was originally designed to manage matrix assembly operations over all elemental topology types, has been modified to operate over homogeneous collections of mesh entities. This newly templated kernel design allows for removal of workset variable resize operations that were formerly required at each loop over a Sierra ToolKit (STK) bucket (nominally, 512 entities in size). Extensive usage of the Standard Template Library (STL) std::vector has been removed in favor of intrinsic Kokkos memory views. In this milestone effort, the transition to Kokkos as the underlying infrastructure to support performance and portability onmore » many-core architectures has been deployed for key matrix algorithmic kernels. A unit-test driven design effort has developed a homogeneous entity algorithm that employs a team-based thread parallelism construct. The STK Single Instruction Multiple Data (SIMD) infrastructure is used to interleave data for improved vectorization. The collective algorithm design, which allows for concurrent threading and SIMD management, has been deployed for the core low-Mach element- based algorithm. Several tests to ascertain SIMD performance on Intel KNL and Haswell architectures have been carried out. The performance test matrix includes evaluation of both low- and higher-order methods. The higher-order low-Mach methodology builds on polynomial promotion of the core low-order control volume nite element method (CVFEM). Performance testing of the Kokkos-view/SIMD design indicates low-order matrix assembly kernel speed-up ranging between two and four times depending on mesh loading and node count. Better speedups are observed for higher-order meshes (currently only P=2 has been tested) especially on KNL. The increased workload per element on higher-order meshes bene ts from the wide SIMD width on KNL machines. Combining multiple threads with SIMD on KNL achieves a 4.6x speedup over the baseline, with assembly timings faster than that observed on Haswell architecture. The computational workload of higher-order meshes, therefore, seems ideally suited for the many-core architecture and justi es further exploration of higher-order on NGP platforms. A Trilinos/Tpetra-based multi-threaded GMRES preconditioned by symmetric Gauss Seidel (SGS) represents the core solver infrastructure for the low-Mach advection/diffusion implicit solves. The threaded solver stack has been tested on small problems on NREL's Peregrine system using the newly developed and deployed Kokkos-view/SIMD kernels. fforts are underway to deploy the Tpetra-based solver stack on NERSC Cori system to benchmark its performance at scale on KNL machines.« less

An assessment of wind tunnel test data on flexible thermal protection materials and results of new fatigue tests of threads

NASA Technical Reports Server (NTRS)

Coe, Charles F.

1985-01-01

Advanced Flexible Reusable Surface Insulation (AFRSI) was developed as a replacement for the low-temperature (white) tiles on the Space Shuttle. The first use of the AFRSI for an Orbiter flight was on the OMS POD of Orbiter (OV-099) for STS-6. Post flight examination after STS-6 showed that damage had occurred to the AFRSI during flight. The failure anomaly between previous wind-tunnel tests and STS-6 prompted a series of additional wind tunnel tests to gain an insight as to the cause of the failure. An assessment of all the past STS-6 wind tunnel tests pointed out the sensitivity of the test results to scaling of dynamic loads due to the difference of boundary layer thickness, and the material properties as a result of exposure to heating. The thread component of the AFRSI was exposed to fatigue testing using an apparatus that applied pulsating aerodynamic loads on the threads similar to the loads caused by an oscillating shock. Comparison of the mean values of the number-of-cycles to failure showed that the history of the thread was the major factor in its performance. The thread and the wind tunnel data suggests a mechanism of failure for the AFRSI.

Novel gold nanoparticle trimer reporter probe combined with dry-reagent cotton thread immunoassay device for rapid human ferritin test.

PubMed

Mao, Xun; Du, Ting-E; Meng, Lili; Song, Tingting

2015-08-19

We reported here for the first time on the use of cotton thread combined with novel gold nanoparticle trimer reporter probe for low-cost, sensitive and rapid detection of a lung cancer related biomarker, human ferritin. A model system comprising ferritin as an analyte and a pair of monoclonal antibodies was used to demonstrate the proof-of-concept on the dry-reagent natural cotton thread immunoassay device. Results indicated that the using of novel gold nanoparticle trimer reporter probe greatly improved the sensitivity comparing with traditional gold nanoparticle reporter probe on the cotton thread immunoassay device. The assay avoids multiple incubation and washing steps performed in most conventional protein analyses. Although qualitative tests are realized by observing the color change of the test zone, quantitative data are obtained by recording the optical responses of the test zone with a commercial scanner and corresponding analysis software. Under optimal conditions, the cotton thread immunoassay device was capable of measuring 10 ng/mL human ferritin under room temperature which is sensitive enough for clinical diagnosis. Moreover, the sample solution employed in the assays is just 8 μL, which is much less than traditional lateral flow strip based biosensors. Copyright © 2015 Elsevier B.V. All rights reserved.

Comparison of Gene Expression in Human Embryonic Stem Cells, hESC-Derived Mesenchymal Stem Cells and Human Mesenchymal Stem Cells.

PubMed

Barbet, Romain; Peiffer, Isabelle; Hatzfeld, Antoinette; Charbord, Pierre; Hatzfeld, Jacques A

2011-01-01

We present a strategy to identify developmental/differentiation and plasma membrane marker genes of the most primitive human Mesenchymal Stem Cells (hMSCs). Using sensitive and quantitative TaqMan Low Density Arrays (TLDA) methodology, we compared the expression of 381 genes in human Embryonic Stem Cells (hESCs), hESC-derived MSCs (hES-MSCs), and hMSCs. Analysis of differentiation genes indicated that hES-MSCs express the sarcomeric muscle lineage in addition to the classical mesenchymal lineages, suggesting they are more primitive than hMSCs. Transcript analysis of membrane antigens suggests that IL1R1(low), BMPR1B(low), FLT4(low), LRRC32(low), and CD34 may be good candidates for the detection and isolation of the most primitive hMSCs. The expression in hMSCs of cytokine genes, such as IL6, IL8, or FLT3LG, without expression of the corresponding receptor, suggests a role for these cytokines in the paracrine control of stem cell niches. Our database may be shared with other laboratories in order to explore the considerable clinical potential of hES-MSCs, which appear to represent an intermediate developmental stage between hESCs and hMSCs.

Dedicated memory structure holding data for detecting available worker thread(s) and informing available worker thread(s) of task(s) to execute

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chiu, George L.; Eichenberger, Alexandre E.; O'Brien, John K. P.

The present disclosure relates generally to a dedicated memory structure (that is, hardware device) holding data for detecting available worker thread(s) and informing available worker thread(s) of task(s) to execute.

Developing eThread Pipeline Using SAGA-Pilot Abstraction for Large-Scale Structural Bioinformatics

PubMed Central

Ragothaman, Anjani; Feinstein, Wei; Jha, Shantenu; Kim, Joohyun

2014-01-01

While most of computational annotation approaches are sequence-based, threading methods are becoming increasingly attractive because of predicted structural information that could uncover the underlying function. However, threading tools are generally compute-intensive and the number of protein sequences from even small genomes such as prokaryotes is large typically containing many thousands, prohibiting their application as a genome-wide structural systems biology tool. To leverage its utility, we have developed a pipeline for eThread—a meta-threading protein structure modeling tool, that can use computational resources efficiently and effectively. We employ a pilot-based approach that supports seamless data and task-level parallelism and manages large variation in workload and computational requirements. Our scalable pipeline is deployed on Amazon EC2 and can efficiently select resources based upon task requirements. We present runtime analysis to characterize computational complexity of eThread and EC2 infrastructure. Based on results, we suggest a pathway to an optimized solution with respect to metrics such as time-to-solution or cost-to-solution. Our eThread pipeline can scale to support a large number of sequences and is expected to be a viable solution for genome-scale structural bioinformatics and structure-based annotation, particularly, amenable for small genomes such as prokaryotes. The developed pipeline is easily extensible to other types of distributed cyberinfrastructure. PMID:24995285

Conceptual waste packaging options for deep borehole disposal

DOE Office of Scientific and Technical Information (OSTI.GOV)

Su, Jiann -Cherng; Hardin, Ernest L.

This report presents four concepts for packaging of radioactive waste for disposal in deep boreholes. Two of these are reference-size packages (11 inch outer diameter) and two are smaller (5 inch) for disposal of Cs/Sr capsules. All four have an assumed length of approximately 18.5 feet, which allows the internal length of the waste volume to be 16.4 feet. However, package length and volume can be scaled by changing the length of the middle, tubular section. The materials proposed for use are low-alloy steels, commonly used in the oil-and-gas industry. Threaded connections between packages, and internal threads used to sealmore » the waste cavity, are common oilfield types. Two types of fill ports are proposed: flask-type and internal-flush. All four package design concepts would withstand hydrostatic pressure of 9,600 psi, with factor safety 2.0. The combined loading condition includes axial tension and compression from the weight of a string or stack of packages in the disposal borehole, either during lower and emplacement of a string, or after stacking of multiple packages emplaced singly. Combined loading also includes bending that may occur during emplacement, particularly for a string of packages threaded together. Flask-type packages would be fabricated and heat-treated, if necessary, before loading waste. The fill port would be narrower than the waste cavity inner diameter, so the flask type is suitable for directly loading bulk granular waste, or loading slim waste canisters (e.g., containing Cs/Sr capsules) that fit through the port. The fill port would be sealed with a tapered, threaded plug, with a welded cover plate (welded after loading). Threaded connections between packages and between packages and a drill string, would be standard drill pipe threads. The internal flush packaging concepts would use semi-flush oilfield tubing, which is internally flush but has a slight external upset at the joints. This type of tubing can be obtained with premium, low-profile threaded connections at each end. The internal-flush design would be suitable for loading waste that arrives from the originating site in weld-sealed, cylindrical canisters. Internal, tapered plugs with sealing filet welds would seal the tubing at each end. The taper would be precisely machined onto both the tubing and the plug, producing a metal-metal sealing surface that is compressed as the package is subjected to hydrostatic pressure. The lower plug would be welded in place before loading, while the upper plug would be placed and welded after loading. Conceptual Waste Packaging Options for Deep Borehole Disposal July 30, 2015 iv Threaded connections between packages would allow emplacement singly or in strings screwed together at the disposal site. For emplacement on a drill string the drill pipe would be connected directly into the top package of a string (using an adapter sub to mate with premium semi-flush tubing threads). Alternatively, for wireline emplacement the same package designs could be emplaced singly using a sub with wireline latch, on the upper end. Threaded connections on the bottom of the lowermost package would allow attachment of a crush box, instrumentation, etc.« less

LONG DURATION FLARE EMISSION: IMPULSIVE HEATING OR GRADUAL HEATING?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Qiu, Jiong; Longcope, Dana W.

Flare emissions in X-ray and EUV wavelengths have previously been modeled as the plasma response to impulsive heating from magnetic reconnection. Some flares exhibit gradually evolving X-ray and EUV light curves, which are believed to result from superposition of an extended sequence of impulsive heating events occurring in different adjacent loops or even unresolved threads within each loop. In this paper, we apply this approach to a long duration two-ribbon flare SOL2011-09-13T22 observed by the Atmosphere Imaging Assembly (AIA). We find that to reconcile with observed signatures of flare emission in multiple EUV wavelengths, each thread should be heated inmore » two phases, an intense impulsive heating followed by a gradual, low-rate heating tail that is attenuated over 20–30 minutes. Each AIA resolved single loop may be composed of several such threads. The two-phase heating scenario is supported by modeling with both a zero-dimensional and a 1D hydrodynamic code. We discuss viable physical mechanisms for the two-phase heating in a post-reconnection thread.« less

Cell-laden composite suture threads for repairing damaged tendons.

PubMed

Costa-Almeida, Raquel; Domingues, Rui M A; Fallahi, Afsoon; Avci, Huseyin; Yazdi, Iman K; Akbari, Mohsen; Reis, Rui L; Tamayol, Ali; Gomes, Manuela E; Khademhosseini, Ali

2018-04-01

Tendons have limited regenerative capacity due to their low cellularity and hypovascular nature, which results in poor clinical outcomes of presently used therapies. As tendon injuries are often observed in active adults, it poses an increasing socio-economic burden on healthcare systems. Currently, suture threads are used during surgical repair to anchor the tissue graft or to connect injured ends. Here, we created composite suture threads coated with a layer of cell-laden hydrogel that can be used for bridging the injured tissue aiming at tendon regeneration. In addition, the fibres can be used to engineer 3-dimensional constructs through textile processes mimicking the architecture and mechanical properties of soft tissues, including tendons and ligaments. Encapsulated human tendon-derived cells migrated within the hydrogel and aligned at the surface of the core thread. An up-regulation of tendon-related genes (scleraxis and tenascin C) and genes involved in matrix remodelling (matrix metalloproteinases 1, matrix metalloproteinases 2) was observed. Cells were able to produce a collagen-rich matrix, remodelling their micro-environment, which is structurally comparable to native tendon tissue. Copyright © 2017 John Wiley & Sons, Ltd.

Hydrazines and carbohydrazides produced from oxidized carbon in earth's primitive environment

NASA Technical Reports Server (NTRS)

Folsome, C. E.; Brittain, A.; Smith, A.; Chang, S.

1981-01-01

Whether abiological organic compounds can be formed from the interactions of energy sources with nitrogen, oxidized carbon and water is held to be of importance in geochemical models of the primordial earth atmosphere. It is reported that experiments using quenched spark discharges through molecular nitrogen on aqueous suspensions of CaCO3 and other reactants to simulate the hydrosphere/atmosphere interface yield hydrazine and carbohydrazine in significant but low yields. Such reactions in primitive aquatic environments may have supplied a pathway for chemical evolution and the origin of life, on a primitive earth in which fully oxidized states of carbon were available for the primary synthesis of organic matter.

Field-Lines-Threaded Model for: (1) the Low Solar Corona; (2) Electrons in the Transition Region; and (3) Solar Energetic Particle Acceleration and Transport

NASA Astrophysics Data System (ADS)

Sokolov, I.; van der Holst, B.; Jin, M.; Gombosi, T. I.; Taktakishvili, A.; Khazanov, G. V.

2013-12-01

In numerical simulations of the solar corona, both for the ambient state and especially for dynamical processes the most computational resources are spent for maintaining the numerical solution in the Low Solar Corona and in the transition region, where the temperature gradients are very sharp and the magnetic field has a complicated topology. The degraded computational efficiency is caused by the need in a highest resolution as well as the use of the fully three-dimensional implicit solver for electron heat conduction. On the other hand, the physical nature of the processes involved is rather simple (which still does not facilitate the numerical methods) as long as the heat fluxes as well as slow plasma motional velocities are aligned with the magnetic field. The Alfven wave turbulence, which is often believed to be the main driver of the solar wind and the main source of the coronal heating, is characterized by the Poynting flux of the waves, which is also aligned with the magnetic field. Therefore, the plasma state in any point of the three-dimensional grid in the Low Solar Corona can be found by solving a set of one-dimensional equations for the magnetic field line ('thread'), which passes through this point and connects it to the chromosphere and to the global Solar Corona. In the present paper we describe an innovative computational technology based upon the use of the magnetic-field-line-threads to find the local solution. We present the development of the AWSoM code of the University of Michigan with the field-lines-threaded Low Solar Corona. In the transition region, where the essentially kinetic description of the electron energy fluxes is required, we solve the Fokker-Plank equation on the system of threads, to achieve the physically consistent description of chromosphere evaporation. The third application for the field-lines-treaded model is the Solar Energetic Particle (SEP) acceleration and transport. Being the natural extension of the Field-Line-Advection Model for Particle Acceleration (FLAMPA), earlier suggested for a single magnetic field line advected with the plasma motion, the multiple-field-lines model allows us to simulate the SEP fluxes at multiple points of possible observation (at the Earth location, at STEREOs, at Mercury).

Thread mapping using system-level model for shared memory multicores

NASA Astrophysics Data System (ADS)

Mitra, Reshmi

Exploring thread-to-core mapping options for a parallel application on a multicore architecture is computationally very expensive. For the same algorithm, the mapping strategy (MS) with the best response time may change with data size and thread counts. The primary challenge is to design a fast, accurate and automatic framework for exploring these MSs for large data-intensive applications. This is to ensure that the users can explore the design space within reasonable machine hours, without thorough understanding on how the code interacts with the platform. Response time is related to the cycles per instructions retired (CPI), taking into account both active and sleep states of the pipeline. This work establishes a hybrid approach, based on Markov Chain Model (MCM) and Model Tree (MT) for system-level steady state CPI prediction. It is designed for shared memory multicore processors with coarse-grained multithreading. The thread status is represented by the MCM states. The program characteristics are modeled as the transition probabilities, representing the system moving between active and suspended thread states. The MT model extrapolates these probabilities for the actual application size (AS) from the smaller AS performance. This aspect of the framework, along with, the use of mathematical expressions for the actual AS performance information, results in a tremendous reduction in the CPI prediction time. The framework is validated using an electromagnetics application. The average performance prediction error for steady state CPI results with 12 different MSs is less than 1%. The total run time of model is of the order of minutes, whereas the actual application execution time is in terms of days.

The Opportunity Cost of Smaller Classes: A State-By-State Spending Analysis. Schools in Crisis: Making Ends Meet

ERIC Educational Resources Information Center

Roza, Marguerite; Ouijdani, Monica

2012-01-01

Two seemingly different threads are in play on the issue of class size. The first is manifested in media reports that tell readers that class sizes are rising to concerning levels. The second thread appears in the work of some researchers and education leaders and suggests that repurposing class-size reduction funds to pay for other reforms may…

Efficient parallelization for AMR MHD multiphysics calculations; implementation in AstroBEAR

NASA Astrophysics Data System (ADS)

Carroll-Nellenback, Jonathan J.; Shroyer, Brandon; Frank, Adam; Ding, Chen

2013-03-01

Current adaptive mesh refinement (AMR) simulations require algorithms that are highly parallelized and manage memory efficiently. As compute engines grow larger, AMR simulations will require algorithms that achieve new levels of efficient parallelization and memory management. We have attempted to employ new techniques to achieve both of these goals. Patch or grid based AMR often employs ghost cells to decouple the hyperbolic advances of each grid on a given refinement level. This decoupling allows each grid to be advanced independently. In AstroBEAR we utilize this independence by threading the grid advances on each level with preference going to the finer level grids. This allows for global load balancing instead of level by level load balancing and allows for greater parallelization across both physical space and AMR level. Threading of level advances can also improve performance by interleaving communication with computation, especially in deep simulations with many levels of refinement. While we see improvements of up to 30% on deep simulations run on a few cores, the speedup is typically more modest (5-20%) for larger scale simulations. To improve memory management we have employed a distributed tree algorithm that requires processors to only store and communicate local sections of the AMR tree structure with neighboring processors. Using this distributed approach we are able to get reasonable scaling efficiency (>80%) out to 12288 cores and up to 8 levels of AMR - independent of the use of threading.

A triaxial supramolecular weave

NASA Astrophysics Data System (ADS)

Lewandowska, Urszula; Zajaczkowski, Wojciech; Corra, Stefano; Tanabe, Junki; Borrmann, Ruediger; Benetti, Edmondo M.; Stappert, Sebastian; Watanabe, Kohei; Ochs, Nellie A. K.; Schaeublin, Robin; Li, Chen; Yashima, Eiji; Pisula, Wojciech; Müllen, Klaus; Wennemers, Helma

2017-11-01

Despite recent advances in the synthesis of increasingly complex topologies at the molecular level, nano- and microscopic weaves have remained difficult to achieve. Only a few diaxial molecular weaves exist—these were achieved by templation with metals. Here, we present an extended triaxial supramolecular weave that consists of self-assembled organic threads. Each thread is formed by the self-assembly of a building block comprising a rigid oligoproline segment with two perylene-monoimide chromophores spaced at 18 Å. Upon π stacking of the chromophores, threads form that feature alternating up- and down-facing voids at regular distances. These voids accommodate incoming building blocks and establish crossing points through CH-π interactions on further assembly of the threads into a triaxial woven superstructure. The resulting micrometre-scale supramolecular weave proved to be more robust than non-woven self-assemblies of the same building block. The uniform hexagonal pores of the interwoven network were able to host iridium nanoparticles, which may be of interest for practical applications.

Thread selection according to power characteristics during context switching on compute nodes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Archer, Charles J.; Blocksome, Michael A.; Randles, Amanda E.

Methods, apparatus, and products are disclosed for thread selection during context switching on a plurality of compute nodes that includes: executing, by a compute node, an application using a plurality of threads of execution, including executing one or more of the threads of execution; selecting, by the compute node from a plurality of available threads of execution for the application, a next thread of execution in dependence upon power characteristics for each of the available threads; determining, by the compute node, whether criteria for a thread context switch are satisfied; and performing, by the compute node, the thread context switchmore » if the criteria for a thread context switch are satisfied, including executing the next thread of execution.« less

Thread selection according to predefined power characteristics during context switching on compute nodes

DOE Office of Scientific and Technical Information (OSTI.GOV)

None, None

Methods, apparatus, and products are disclosed for thread selection during context switching on a plurality of compute nodes that includes: executing, by a compute node, an application using a plurality of threads of execution, including executing one or more of the threads of execution; selecting, by the compute node from a plurality of available threads of execution for the application, a next thread of execution in dependence upon power characteristics for each of the available threads; determining, by the compute node, whether criteria for a thread context switch are satisfied; and performing, by the compute node, the thread context switchmore » if the criteria for a thread context switch are satisfied, including executing the next thread of execution.« less

Non-canonical Wnt signalling modulates the endothelial shear stress flow sensor in vascular remodelling

PubMed Central

Franco, Claudio A; Jones, Martin L; Bernabeu, Miguel O; Vion, Anne-Clemence; Barbacena, Pedro; Fan, Jieqing; Mathivet, Thomas; Fonseca, Catarina G; Ragab, Anan; Yamaguchi, Terry P; Coveney, Peter V; Lang, Richard A; Gerhardt, Holger

2016-01-01

Endothelial cells respond to molecular and physical forces in development and vascular homeostasis. Deregulation of endothelial responses to flow-induced shear is believed to contribute to many aspects of cardiovascular diseases including atherosclerosis. However, how molecular signals and shear-mediated physical forces integrate to regulate vascular patterning is poorly understood. Here we show that endothelial non-canonical Wnt signalling regulates endothelial sensitivity to shear forces. Loss of Wnt5a/Wnt11 renders endothelial cells more sensitive to shear, resulting in axial polarization and migration against flow at lower shear levels. Integration of flow modelling and polarity analysis in entire vascular networks demonstrates that polarization against flow is achieved differentially in artery, vein, capillaries and the primitive sprouting front. Collectively our data suggest that non-canonical Wnt signalling stabilizes forming vascular networks by reducing endothelial shear sensitivity, thus keeping vessels open under low flow conditions that prevail in the primitive plexus. DOI: http://dx.doi.org/10.7554/eLife.07727.001 PMID:26845523

Deep levels in as-grown and electron-irradiated n-type GaN studied by deep level transient spectroscopy and minority carrier transient spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Duc, Tran Thien; School of Engineering Physics, Hanoi University of Science and Technology, 1 Dai Co Viet Road, Hanoi; Pozina, Galia

2016-03-07

Development of high performance GaN-based devices is strongly dependent on the possibility to control and understand defects in material. Important information about deep level defects is obtained by deep level transient spectroscopy and minority carrier transient spectroscopy on as-grown and electron irradiated n-type bulk GaN with low threading dislocation density produced by halide vapor phase epitaxy. One hole trap labelled H1 (E{sub V} + 0.34 eV) has been detected on as-grown GaN sample. After 2 MeV electron irradiation, the concentration of H1 increases and at fluences higher than 5 × 10{sup 14 }cm{sup −2}, a second hole trap labelled H2 is observed. Simultaneously, the concentration of twomore » electron traps, labelled T1 (E{sub C} – 0.12 eV) and T2 (E{sub C} – 0.23 eV), increases. By studying the increase of the defect concentration versus electron irradiation fluence, the introduction rate of T1 and T2 using 2 MeV- electrons was determined to be 7 × 10{sup −3 }cm{sup −1} and 0.9 cm{sup −1}, respectively. Due to the low introduction rate of T1, it is suggested that the defect is associated with a complex. The high introduction rate of trap H1 and T2 suggests that the defects are associated with primary intrinsic defects or complexes. Some deep levels previously observed in irradiated GaN layers with higher threading dislocation densities are not detected in present investigation. It is therefore suggested that the absent traps may be related to primary defects segregated around dislocations.« less

Modified locking thread form for fastener

NASA Technical Reports Server (NTRS)

Roopnarine, (Inventor); Vranish, John D. (Inventor)

1998-01-01

A threaded fastener has a standard part with a standard thread form characterized by thread walls with a standard included angle, and a modified part complementary to the standard part having a modified thread form characterized by thread walls which are symmetrically inclined with a modified included angle that is different from the standard included angle of the standard part's thread walls, such that the threads of one part make pre-loaded edge contact with the thread walls of the other part. The thread form of the modified part can have an included angle that is greater, less, or compound as compared to the included angle of the standard part. The standard part may be a bolt and the modified part a nut, or vice versa. The modified thread form holds securely even under large vibrational forces, it permits bi-directional use of standard mating threads, is impervious to the build up of tolerances and can be manufactured with a wider range of tolerances without loss of functionality, and distributes loading stresses (per thread) in a manner that decreases the possibility of single thread failure.

Defect structure of high temperature hydride vapor phase epitaxy-grown epitaxial (0 0 0 1) AlN/sapphire using growth mode modification process

NASA Astrophysics Data System (ADS)

Su, Xujun; Zhang, Jicai; Huang, Jun; Zhang, Jinping; Wang, Jianfeng; Xu, Ke

2017-06-01

Defect structures were investigated by transmission electron microscopy for AlN/sapphire (0 0 0 1) epilayers grown by high temperature hydride vapor phase epitaxy using a growth mode modification process. The defect structures, including threading dislocations, inversion domains, and voids, were analyzed by diffraction contrast, high-resolution imaging, and convergent beam diffraction. AlN film growth was initiated at 1450 °C with high V/III ratio for 8 min. This was followed by low V/III ratio growth for 12 min. The near-interfacial region shows a high density of threading dislocations and inversion domains. Most of these dislocations have Burgers vector b = 1/3〈1 1 2 0〉 and were reduced with the formation of dislocation loops. In the middle range 400 nm < h < 2 μm, dislocations gradually aggregated and reduced to ∼109 cm-2. The inversion domains have a shuttle-like shape with staggered boundaries that deviate by ∼ ±5° from the c axis. Above 2 μm thickness, the film consists of isolated threading dislocations with a total density of 8 × 108 cm-2. Most of threading dislocations are either pure edge or mixed dislocations. The threading dislocation reduction in these films is associated with dislocation loops formation and dislocation aggregation-interaction during island growth with high V/III ratio.

Tholeiitic basalt magmatism of Kilauea and Mauna Loa volcanoes of Hawaii

USGS Publications Warehouse

Murata, K.J.

1970-01-01

The primitive magmas of Kilauca and Mauna Loa are generated by partial melting of mantle peridotite at depths of -60 km or more. Results of high-pressure melting experiments indicate that the primitive melt must contain at least 20% MgO in order to have olivine as a liquidus mineral. The least fractionated lavas of both volcanoes have olivine (Fa13) on the liquidus at 1 atmosphere, suggesting that the only substance lost from the primitive melt, during a rather rapid ascent to the surface, is olivine. This relation allows the primitive composition to be computed by adding olivine to the composition of an erupted lava until total MgO is at least 20 percent. Although roughly similar, historic lavas of the two volcanoes show a consistent difference in composition. The primitive melt of Mauna Loa contains 20% more dissolved orthopyroxene, a high-temperature melting phase in the mantle, and is deficient in elements such as potassium, uranium, and niobium, which presumably occur in minor low-melting phases. Mauna Loa appears to be the older volcano, deriving its magma at higher temperature and greater depth from a more depleted source rock. ?? 1970 Springer-Verlag.

Parallel language constructs for tensor product computations on loosely coupled architectures

NASA Technical Reports Server (NTRS)

Mehrotra, Piyush; Vanrosendale, John

1989-01-01

Distributed memory architectures offer high levels of performance and flexibility, but have proven awkard to program. Current languages for nonshared memory architectures provide a relatively low level programming environment, and are poorly suited to modular programming, and to the construction of libraries. A set of language primitives designed to allow the specification of parallel numerical algorithms at a higher level is described. Tensor product array computations are focused on along with a simple but important class of numerical algorithms. The problem of programming 1-D kernal routines is focused on first, such as parallel tridiagonal solvers, and then how such parallel kernels can be combined to form parallel tensor product algorithms is examined.

Data Parallel Bin-Based Indexing for Answering Queries on Multi-Core Architectures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gosink, Luke; Wu, Kesheng; Bethel, E. Wes

2009-06-02

The multi-core trend in CPUs and general purpose graphics processing units (GPUs) offers new opportunities for the database community. The increase of cores at exponential rates is likely to affect virtually every server and client in the coming decade, and presents database management systems with a huge, compelling disruption that will radically change how processing is done. This paper presents a new parallel indexing data structure for answering queries that takes full advantage of the increasing thread-level parallelism emerging in multi-core architectures. In our approach, our Data Parallel Bin-based Index Strategy (DP-BIS) first bins the base data, and then partitionsmore » and stores the values in each bin as a separate, bin-based data cluster. In answering a query, the procedures for examining the bin numbers and the bin-based data clusters offer the maximum possible level of concurrency; each record is evaluated by a single thread and all threads are processed simultaneously in parallel. We implement and demonstrate the effectiveness of DP-BIS on two multi-core architectures: a multi-core CPU and a GPU. The concurrency afforded by DP-BIS allows us to fully utilize the thread-level parallelism provided by each architecture--for example, our GPU-based DP-BIS implementation simultaneously evaluates over 12,000 records with an equivalent number of concurrently executing threads. In comparing DP-BIS's performance across these architectures, we show that the GPU-based DP-BIS implementation requires significantly less computation time to answer a query than the CPU-based implementation. We also demonstrate in our analysis that DP-BIS provides better overall performance than the commonly utilized CPU and GPU-based projection index. Finally, due to data encoding, we show that DP-BIS accesses significantly smaller amounts of data than index strategies that operate solely on a column's base data; this smaller data footprint is critical for parallel processors that possess limited memory resources (e.g., GPUs).« less

An interval logic for higher-level temporal reasoning

NASA Technical Reports Server (NTRS)

Schwartz, R. L.; Melliar-Smith, P. M.; Vogt, F. H.; Plaisted, D. A.

1983-01-01

Prior work explored temporal logics, based on classical modal logics, as a framework for specifying and reasoning about concurrent programs, distributed systems, and communications protocols, and reported on efforts using temporal reasoning primitives to express very high level abstract requirements that a program or system is to satisfy. Based on experience with those primitives, this report describes an Interval Logic that is more suitable for expressing such higher level temporal properties. The report provides a formal semantics for the Interval Logic, and several examples of its use. A description of decision procedures for the logic is also included.

SPANISH PEAKS PRIMITIVE AREA, MONTANA.

USGS Publications Warehouse

Calkins, James A.; Pattee, Eldon C.

1984-01-01

A mineral survey of the Spanish Peaks Primitive Area, Montana, disclosed a small low-grade deposit of demonstrated chromite and asbestos resources. The chances for discovery of additional chrome resources are uncertain and the area has little promise for the occurrence of other mineral or energy resources. A reevaluation, sampling at depth, and testing for possible extensions of the Table Mountain asbestos and chromium deposit should be undertaken in the light of recent interpretations regarding its geologic setting.

Comparative Performance Analysis of Coarse Solvers for Algebraic Multigrid on Multicore and Manycore Architectures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Druinsky, Alex; Ghysels, Pieter; Li, Xiaoye S.

In this paper, we study the performance of a two-level algebraic-multigrid algorithm, with a focus on the impact of the coarse-grid solver on performance. We consider two algorithms for solving the coarse-space systems: the preconditioned conjugate gradient method and a new robust HSS-embedded low-rank sparse-factorization algorithm. Our test data comes from the SPE Comparative Solution Project for oil-reservoir simulations. We contrast the performance of our code on one 12-core socket of a Cray XC30 machine with performance on a 60-core Intel Xeon Phi coprocessor. To obtain top performance, we optimized the code to take full advantage of fine-grained parallelism andmore » made it thread-friendly for high thread count. We also developed a bounds-and-bottlenecks performance model of the solver which we used to guide us through the optimization effort, and also carried out performance tuning in the solver’s large parameter space. Finally, as a result, significant speedups were obtained on both machines.« less

Low-Thermal-Resistance Baseplate Mounting

NASA Technical Reports Server (NTRS)

Perreault, W. T.

1984-01-01

Low-thermal-resistance mounting achieved by preloading baseplate to slight convexity with screws threaded through beam. As mounting bolts around edge of base-place tightened, baseplate and cold plate contact first in center, with region of intimate contact spreading outward as bolts tightened.

Mental models for cognitive control

NASA Astrophysics Data System (ADS)

Schilling, Malte; Cruse, Holk; Schmitz, Josef

2007-05-01

Even so called "simple" organisms as insects are able to fastly adapt to changing conditions of their environment. Their behaviour is affected by many external influences and only its variability and adaptivity permits their survival. An intensively studied example concerns hexapod walking. 1,2 Complex walking behaviours in stick insects have been analysed and the results were used to construct a reactive model that controls walking in a robot. This model is now extended by higher levels of control: as a bottom-up approach the low-level reactive behaviours are modulated and activated through a medium level. In addition, the system grows up to an upper level for cognitive control of the robot: Cognition - as the ability to plan ahead - and cognitive skills involve internal representations of the subject itself and its environment. These representations are used for mental simulations: In difficult situations, for which neither motor primitives, nor whole sequences of these exist, available behaviours are varied and applied in the internal model while the body itself is decoupled from the controlling modules. The result of the internal simulation is evaluated. Successful actions are learned and applied to the robot. This constitutes a level for planning. Its elements (movements, behaviours) are embodied in the lower levels, whereby their meaning arises directly from these levels. The motor primitives are situation models represented as neural networks. The focus of this work concerns the general architecture of the framework as well as the reactive basic layer of the bottom-up architecture and its connection to higher level functions and its application on an internal model.

Cutting thread at flexible endoscopy.

PubMed

Gong, F; Swain, P; Kadirkamanathan, S; Hepworth, C; Laufer, J; Shelton, J; Mills, T

1996-12-01

New thread-cutting techniques were developed for use at flexible endoscopy. A guillotine was designed to follow and cut thread at the endoscope tip. A new method was developed for guiding suture cutters. Efficacy of Nd: YAG laser cutting of threads was studied. Experimental and clinical experience with thread-cutting methods is presented. A 2.4 mm diameter flexible thread-cutting guillotine was constructed featuring two lateral holes with sharp edges through which sutures to be cut are passed. Standard suture cutters were guided by backloading thread through the cutters extracorporeally. A snare cutter was constructed to retrieve objects sewn to tissue. Efficacy and speed of Nd: YAG laser in cutting twelve different threads were studied. The guillotine cut thread faster (p < 0.05) than standard suture cutters. Backloading thread shortened time taken to cut thread (p < 0.001) compared with free-hand cutting. Nd: YAG laser was ineffective in cutting uncolored threads and slower than mechanical cutters. Results of thread cutting in clinical studies using sewing machine (n = 77 cutting episodes in 21 patients), in-vivo experiments (n = 156), and postsurgical cases (n = 15 over 15 years) are presented. New thread-cutting methods are described and their efficacy demonstrated in experimental and clinical studies.

Tool Removes Coil-Spring Thread Inserts

NASA Technical Reports Server (NTRS)

Collins, Gerald J., Jr.; Swenson, Gary J.; Mcclellan, J. Scott

1991-01-01

Tool removes coil-spring thread inserts from threaded holes. Threads into hole, pries insert loose, grips insert, then pulls insert to thread it out of hole. Effects essentially reverse of insertion process to ease removal and avoid further damage to threaded inner surface of hole.

Red blood cell transport mechanisms in polyester thread-based blood typing devices.

PubMed

Nilghaz, Azadeh; Ballerini, David R; Guan, Liyun; Li, Lizi; Shen, Wei

2016-02-01

A recently developed blood typing diagnostic based on a polyester thread substrate has shown great promise for use in medical emergencies and in impoverished regions. The device is easy to use and transport, while also being inexpensive, accurate, and rapid. This study used a fluorescent confocal microscope to delve deeper into how red blood cells were behaving within the polyester thread-based diagnostic at the cellular level, and how plasma separation could be made to visibly occur on the thread, making it possible to identify blood type in a single step. Red blood cells were stained and the plasma phase dyed with fluorescent compounds to enable them to be visualised under the confocal microscope at high magnification. The mechanisms uncovered were in surprising contrast with those found for a similar, paper-based method. Red blood cell aggregates did not flow over each other within the thread substrate as expected, but suffered from a restriction to their flow which resulted in the chromatographic separation of the RBCs from the liquid phase of the blood. It is hoped that these results will lead to the optimisation of the method to enable more accurate and sensitive detection, increasing the range of blood systems that can be detected.

Three-dimensional printing spiders: back-and-forth glue application yields silk anchorages with high pull-off resistance under varying loading situations

PubMed Central

Herberstein, Marie E.

2017-01-01

The anchorage of structures is a crucial element of construction, both for humans and animals. Spiders use adhesive plaques to attach silk threads to substrates. Both biological and artificial adhesive structures usually have an optimal loading angle, and are prone to varying loading situations. Silk anchorages, however, must cope with loading in highly variable directions. Here we show that the detachment forces of thread anchorages of orb-web spiders are highly robust against pulling in different directions. This is gained by a two-step back-and-forth spinning pattern during the rapid production of the adhesive plaque, which shifts the thread insertion point towards the plaque centre and forms a flexible tree root-like network of branching fibres around the loading point. Using a morphometric approach and a tape-and-thread model we show that neither area, nor width of the plaque, but the shift of the loading point towards the plaque centre has the highest effect on pull-off resistance. This is explained by a circular propagation of the delamination crack with a low peeling angle. We further show that silken attachment discs are highly directional and adjusted to provide maximal performance in the upstream dragline. These results show that the way the glue is applied, crucially enhances the toughness of the anchorage without the need of additional material intake. This work is a starting point to study the evolution of tough and universal thread anchorages among spiders, and to develop bioinspired ‘instant’ anchorages of thread- and cable-like structures to a broad bandwidth of substrates. PMID:28228539

Three-dimensional printing spiders: back-and-forth glue application yields silk anchorages with high pull-off resistance under varying loading situations.

PubMed

Wolff, Jonas O; Herberstein, Marie E

2017-02-01

The anchorage of structures is a crucial element of construction, both for humans and animals. Spiders use adhesive plaques to attach silk threads to substrates. Both biological and artificial adhesive structures usually have an optimal loading angle, and are prone to varying loading situations. Silk anchorages, however, must cope with loading in highly variable directions. Here we show that the detachment forces of thread anchorages of orb-web spiders are highly robust against pulling in different directions. This is gained by a two-step back-and-forth spinning pattern during the rapid production of the adhesive plaque, which shifts the thread insertion point towards the plaque centre and forms a flexible tree root-like network of branching fibres around the loading point. Using a morphometric approach and a tape-and-thread model we show that neither area, nor width of the plaque, but the shift of the loading point towards the plaque centre has the highest effect on pull-off resistance. This is explained by a circular propagation of the delamination crack with a low peeling angle. We further show that silken attachment discs are highly directional and adjusted to provide maximal performance in the upstream dragline. These results show that the way the glue is applied, crucially enhances the toughness of the anchorage without the need of additional material intake. This work is a starting point to study the evolution of tough and universal thread anchorages among spiders, and to develop bioinspired 'instant' anchorages of thread- and cable-like structures to a broad bandwidth of substrates. © 2017 The Author(s).

Thread gauge for measuring thread pitch diameters

DOEpatents

Brewster, A.L.

1985-11-19

A thread gauge which attaches to a vernier caliper to measure the thread pitch diameter of both externally threaded and internally threaded parts is disclosed. A pair of anvils are externally threaded with threads having the same pitch as those of the threaded part. Each anvil is mounted on a stem having a ball on which the anvil can rotate to properly mate with the parts to which the anvils are applied. The stems are detachably secured to the caliper blades by attachment collars having keyhole openings for receiving the stems and caliper blades. A set screw is used to secure each collar on its caliper blade. 2 figs.

Thread gauge for measuring thread pitch diameters

DOEpatents

Brewster, Albert L.

1985-01-01

A thread gauge which attaches to a vernier caliper to measure the thread pitch diameter of both externally threaded and internally threaded parts. A pair of anvils are externally threaded with threads having the same pitch as those of the threaded part. Each anvil is mounted on a stem having a ball on which the anvil can rotate to properly mate with the parts to which the anvils are applied. The stems are detachably secured to the caliper blades by attachment collars having keyhole openings for receiving the stems and caliper blades. A set screw is used to secure each collar on its caliper blade.

A two-level generative model for cloth representation and shape from shading.

PubMed

Han, Feng; Zhu, Song-Chun

2007-07-01

In this paper, we present a two-level generative model for representing the images and surface depth maps of drapery and clothes. The upper level consists of a number of folds which will generate the high contrast (ridge) areas with a dictionary of shading primitives (for 2D images) and fold primitives (for 3D depth maps). These primitives are represented in parametric forms and are learned in a supervised learning phase using 3D surfaces of clothes acquired through photometric stereo. The lower level consists of the remaining flat areas which fill between the folds with a smoothness prior (Markov random field). We show that the classical ill-posed problem-shape from shading (SFS) can be much improved by this two-level model for its reduced dimensionality and incorporation of middle-level visual knowledge, i.e., the dictionary of primitives. Given an input image, we first infer the folds and compute a sketch graph using a sketch pursuit algorithm as in the primal sketch [10], [11]. The 3D folds are estimated by parameter fitting using the fold dictionary and they form the "skeleton" of the drapery/cloth surfaces. Then, the lower level is computed by conventional SFS method using the fold areas as boundary conditions. The two levels interact at the final stage by optimizing a joint Bayesian posterior probability on the depth map. We show a number of experiments which demonstrate more robust results in comparison with state-of-the-art work. In a broader scope, our representation can be viewed as a two-level inhomogeneous MRF model which is applicable to general shape-from-X problems. Our study is an attempt to revisit Marr's idea [23] of computing the 2(1/2)D sketch from primal sketch. In a companion paper [2], we study shape from stereo based on a similar two-level generative sketch representation.

Exploiting replication in distributed systems

NASA Technical Reports Server (NTRS)

Birman, Kenneth P.; Joseph, T. A.

1989-01-01

Techniques are examined for replicating data and execution in directly distributed systems: systems in which multiple processes interact directly with one another while continuously respecting constraints on their joint behavior. Directly distributed systems are often required to solve difficult problems, ranging from management of replicated data to dynamic reconfiguration in response to failures. It is shown that these problems reduce to more primitive, order-based consistency problems, which can be solved using primitives such as the reliable broadcast protocols. Moreover, given a system that implements reliable broadcast primitives, a flexible set of high-level tools can be provided for building a wide variety of directly distributed application programs.

Flexible wire-shaped strain sensor from cotton thread for human health and motion detection.

PubMed

Li, Yuan-Qing; Huang, Pei; Zhu, Wei-Bin; Fu, Shao-Yun; Hu, Ning; Liao, Kin

2017-03-21

In this work, a wire-shaped flexible strain sensor was fabricated by encapsulating conductive carbon thread (CT) with polydimethylsiloxane (PDMS) elastomer. The key strain sensitive material, CT, was prepared by pyrolysing cotton thread in N 2 atmosphere. The CT/PDMS composite wire shows a typical piezo-resistive behavior with high strain sensitivity. The gauge factors (GF) calculated at low strain of 0-4% and high strain of 8-10% are 8.7 and 18.5, respectively, which are much higher than that of the traditional metallic strain sensor (GF around 2). The wire-shaped CT/PDMS composite sensor shows excellent response to cyclic tensile loading within the strain range of 0-10%, the frequency range of 0.01-10 Hz, to up to 2000 cycles. The potential of the wire senor as wearable strain sensor is demonstrated by the finger motion and blood pulse monitoring. Featured by the low costs of cotton wire and PDMS resin, the simple structure and fabrication technique, as well as high performance with miniaturized size, the wire-shaped sensor based on CT/PDMS composite is believed to have a great potential for application in wearable electronics for human health and motion monitoring.

Composition and substrate-dependent strength of the silken attachment discs in spiders

PubMed Central

Grawe, Ingo; Wolff, Jonas O.; Gorb, Stanislav N.

2014-01-01

Araneomorph spiders have evolved different silks with dissimilar material properties, serving different purposes. The two-compound pyriform secretion is used to glue silk threads to substrates or to other threads. It is applied in distinct patterns, called attachment discs. Although ubiquitously found in spider silk applications and hypothesized to be strong and versatile at low material consumption, the performance of attachment discs on different substrates remains unknown. Here, we analyse the detachment forces and fracture mechanics of the attachment discs spun by five different species on three different substrates, by pulling on the upstream part of the attached thread. Results show that although the adhesion of the pyriform glue is heavily affected by the substrate, even on Teflon it is frequently strong enough to hold the spider's weight. As plant surfaces are often difficult to wet, they are hypothesized to be the major driving force for evolution of the pyriform secretion. PMID:25030386

The Lifferth Dome for Small Telescopes

NASA Astrophysics Data System (ADS)

Wilson, B. L.; Olsen, C. S.; Iverson, E. P.; Paget, A.; Lifferth, W.; Brown, P. J.; Moody, J. W.

2004-12-01

The Lifferth Dome is a pull-off roof designed for small telescopes and other observational equipment. It was specifically designed for the needs of the ROVOR project. The roof itself is completely removed from the observatory housing walls and cranked off to the side below the optical horizon. This is done using two swing arms on either side of the observatory that work in unison to lift the roof off the structure and rotate down and away into a cleared location. The torque is provided by a threaded rod connected to an electric motor at the back of the building. As the motor rotates, the threads turn through a threaded sleeve connected directly to the support arms. Advantages to this design are no lost horizon, no roller surfaces to keep clean, low power and simple limit switches. Operation is by computer control using by National Instruments LabVIEW via the internet. We present its design and construction.

Energy Trapping, Release, and Transport in Three Dimensional Energetic Solids and Molecular Crystals.

DTIC Science & Technology

1986-06-30

excited state and the correlation primitives. These additions had little effect on the tTi ground-state energy. Also included in this table is an...an additional s and p primitive was placed on the C atom and both optimised-with little effect. These were then removed. Finally, the calculation was...the excited vibrational and rotational states of nitromethane have been studied, little work has been done on its low-lying excited electronic states

Generic extravehicular (EVA) and telerobot task primitives for analysis, design, and integration. Version 1.0: Reference compilation for the EVA and telerobotics communities

NASA Technical Reports Server (NTRS)

Smith, Jeffrey H.; Drews, Michael

1990-01-01

The results are described of an effort to establish commonality and standardization of generic crew extravehicular (crew-EVA) and telerobotic task analysis primitives used for the study of spaceborne operations. Although direct crew-EVA plans are the most visible output of spaceborne operations, significant ongoing efforts by a wide variety of projects and organizations also require tools for estimation of crew-EVA and telerobotic times. Task analysis tools provide estimates for input to technical and cost tradeoff studies. A workshop was convened to identify the issues and needs to establish a common language and syntax for task analysis primitives. In addition, the importance of such a syntax was shown to have precedence over the level to which such a syntax is applied. The syntax, lists of crew-EVA and telerobotic primitives, and the data base in diskette form are presented.

Emergence of Functional Hierarchy in a Multiple Timescale Neural Network Model: A Humanoid Robot Experiment

PubMed Central

Yamashita, Yuichi; Tani, Jun

2008-01-01

It is generally thought that skilled behavior in human beings results from a functional hierarchy of the motor control system, within which reusable motor primitives are flexibly integrated into various sensori-motor sequence patterns. The underlying neural mechanisms governing the way in which continuous sensori-motor flows are segmented into primitives and the way in which series of primitives are integrated into various behavior sequences have, however, not yet been clarified. In earlier studies, this functional hierarchy has been realized through the use of explicit hierarchical structure, with local modules representing motor primitives in the lower level and a higher module representing sequences of primitives switched via additional mechanisms such as gate-selecting. When sequences contain similarities and overlap, however, a conflict arises in such earlier models between generalization and segmentation, induced by this separated modular structure. To address this issue, we propose a different type of neural network model. The current model neither makes use of separate local modules to represent primitives nor introduces explicit hierarchical structure. Rather than forcing architectural hierarchy onto the system, functional hierarchy emerges through a form of self-organization that is based on two distinct types of neurons, each with different time properties (“multiple timescales”). Through the introduction of multiple timescales, continuous sequences of behavior are segmented into reusable primitives, and the primitives, in turn, are flexibly integrated into novel sequences. In experiments, the proposed network model, coordinating the physical body of a humanoid robot through high-dimensional sensori-motor control, also successfully situated itself within a physical environment. Our results suggest that it is not only the spatial connections between neurons but also the timescales of neural activity that act as important mechanisms leading to functional hierarchy in neural systems. PMID:18989398

Low cost microfluidic device based on cotton threads for electroanalytical application.

PubMed

Agustini, Deonir; Bergamini, Márcio F; Marcolino-Junior, Luiz Humberto

2016-01-21

Microfluidic devices are an interesting alternative for performing analytical assays, due to the speed of analyses, reduced sample, reagent and solvent consumption and less waste generation. However, the high manufacturing costs still prevent the massive use of these devices worldwide. Here, we present the construction of a low cost microfluidic thread-based electroanalytical device (μTED), employing extremely cheap materials and a manufacturing process free of equipment. The microfluidic channels were built with cotton threads and the estimated cost per device was only $0.39. The flow of solutions (1.12 μL s(-1)) is generated spontaneously due to the capillary forces, eliminating the use of any pumping system. To demonstrate the analytical performance of the μTED, a simultaneous determination of acetaminophen (ACT) and diclofenac (DCF) was performed by multiple pulse amperometry (MPA). A linear dynamic range (LDR) of 10 to 320 μmol L(-1) for both species, a limit of detection (LOD) and a limit of quantitation (LOQ) of 1.4 and 4.7 μmol L(-1) and 2.5 and 8.3 μmol L(-1) for ACT and DCF, respectively, as well as an analytical frequency of 45 injections per hour were reached. Thus, the proposed device has shown potential to extend the use of microfluidic analytical devices, due to its simplicity, low cost and good analytical performance.

Evolvable Neural Software System

NASA Technical Reports Server (NTRS)

Curtis, Steven A.

2009-01-01

The Evolvable Neural Software System (ENSS) is composed of sets of Neural Basis Functions (NBFs), which can be totally autonomously created and removed according to the changing needs and requirements of the software system. The resulting structure is both hierarchical and self-similar in that a given set of NBFs may have a ruler NBF, which in turn communicates with other sets of NBFs. These sets of NBFs may function as nodes to a ruler node, which are also NBF constructs. In this manner, the synthetic neural system can exhibit the complexity, three-dimensional connectivity, and adaptability of biological neural systems. An added advantage of ENSS over a natural neural system is its ability to modify its core genetic code in response to environmental changes as reflected in needs and requirements. The neural system is fully adaptive and evolvable and is trainable before release. It continues to rewire itself while on the job. The NBF is a unique, bilevel intelligence neural system composed of a higher-level heuristic neural system (HNS) and a lower-level, autonomic neural system (ANS). Taken together, the HNS and the ANS give each NBF the complete capabilities of a biological neural system to match sensory inputs to actions. Another feature of the NBF is the Evolvable Neural Interface (ENI), which links the HNS and ANS. The ENI solves the interface problem between these two systems by actively adapting and evolving from a primitive initial state (a Neural Thread) to a complicated, operational ENI and successfully adapting to a training sequence of sensory input. This simulates the adaptation of a biological neural system in a developmental phase. Within the greater multi-NBF and multi-node ENSS, self-similar ENI s provide the basis for inter-NBF and inter-node connectivity.

Role of Massive Stars in the Evolution of Primitive Galaxies

NASA Technical Reports Server (NTRS)

Heap, Sara

2012-01-01

An important factor controlling galaxy evolution is feedback from massive stars. It is believed that the nature and intensity of stellar feedback changes as a function of galaxy mass and metallicity. At low mass and metallicity, feedback from massive stars is mainly in the form of photoionizing radiation. At higher mass and metallicity, it is in stellar winds. IZw 18 is a local blue, compact dwarf galaxy that meets the requirements for a primitive galaxy: low halo mass greater than 10(exp 9)Msun, strong photoionizing radiation, no galactic outflow, and very low metallicity,log(O/H)+12=7.2. We will describe the properties of massive stars and their role in the evolution of IZw 18, based on analysis of ultraviolet images and spectra obtained with HST.

78 FR 76815 - Steel Threaded Rod From India: Preliminary Affirmative Countervailing Duty Determination and...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-19

... DEPARTMENT OF COMMERCE International Trade Administration [C-533-856] Steel Threaded Rod From... exporters of steel threaded rod from India. The period of investigation (``POI'') is January 1, 2012... this investigation is steel threaded rod. Steel threaded rod is certain threaded rod, bar, or studs, of...

Threaded-Field-Line Model for the Transition Region and Solar Corona

NASA Astrophysics Data System (ADS)

Sokolov, I.; van der Holst, B.; Gombosi, T. I.

2014-12-01

In numerical simulations of the solar corona, both for the ambient state and especially for dynamical processes the most computational resources are spent for maintaining the numerical solution in the Low Solar Corona and in the transition region, where the temperature gradients are very sharp and the magnetic field has a complicated topology. The degraded computational efficiency is caused by the need in a highest resolution as well as the use of the fully three-dimensional implicit solver for electron heat conduction. On the other hand, the physical nature of the processes involved is rather simple (which still does not facilitate the numerical methods) as long as the heat fluxes as well as slow plasma motional velocities are aligned with the magnetic field. The Alfven wave turbulence, which is often believed to be the main driver of the solar wind and the main source of the coronal heating, is characterized by the Poynting flux of the waves, which is also aligned with the magnetic field. Therefore, the plasma state in any point of the three-dimensional grid in the Low Solar Corona can be found by solving a set of one-dimensional equations for the magnetic field line ("thread"), which passes through this point and connects it to the chromosphere and to the global Solar Corona. In the present paper we describe an innovative computational technology based upon the use of the magnetic-field-line-threads to forlmulate the boundary condition for the global solar corona model which traces the connection of each boundary point to the cromosphere along the threads.

Multithreaded Stochastic PDES for Reactions and Diffusions in Neurons.

PubMed

Lin, Zhongwei; Tropper, Carl; Mcdougal, Robert A; Patoary, Mohammand Nazrul Ishlam; Lytton, William W; Yao, Yiping; Hines, Michael L

2017-07-01

Cells exhibit stochastic behavior when the number of molecules is small. Hence a stochastic reaction-diffusion simulator capable of working at scale can provide a more accurate view of molecular dynamics within the cell. This paper describes a parallel discrete event simulator, Neuron Time Warp-Multi Thread (NTW-MT), developed for the simulation of reaction diffusion models of neurons. To the best of our knowledge, this is the first parallel discrete event simulator oriented towards stochastic simulation of chemical reactions in a neuron. The simulator was developed as part of the NEURON project. NTW-MT is optimistic and thread-based, which attempts to capitalize on multi-core architectures used in high performance machines. It makes use of a multi-level queue for the pending event set and a single roll-back message in place of individual anti-messages to disperse contention and decrease the overhead of processing rollbacks. Global Virtual Time is computed asynchronously both within and among processes to get rid of the overhead for synchronizing threads. Memory usage is managed in order to avoid locking and unlocking when allocating and de-allocating memory and to maximize cache locality. We verified our simulator on a calcium buffer model. We examined its performance on a calcium wave model, comparing it to the performance of a process based optimistic simulator and a threaded simulator which uses a single priority queue for each thread. Our multi-threaded simulator is shown to achieve superior performance to these simulators. Finally, we demonstrated the scalability of our simulator on a larger CICR model and a more detailed CICR model.

Stability comparison between commercially available mini-implants and a novel design: part 1.

PubMed

Hong, Christine; Lee, Haofu; Webster, Richard; Kwak, Jinny; Wu, Benjamin M; Moon, Won

2011-07-01

To compare mechanical stability among five mini-implant designs--a newly invented design and four commercially available designs that vary by shape and threading; to calculate external surface area of each design using high-resolution micro-computed tomography; and to evaluate the relationship between surface area and stability results. The four commercially available mini-implants--single-threaded and cylindrical (SC), single-threaded and tapered (ST), double-threaded and cylindrical (DC), double-threaded and tapered (DT)--and a new implant that is designed to engage mostly in cortical bone with shorter and wider dimensions (N1) were inserted in simulated bone with cortical and trabecular bone layers. The mechanical study consisted of torque measurements and lateral displacement tests. External surface area was computed using a 25-µm micro-CT. Maximum insertion torque, maximum removal torque, and force levels for displacements were the highest in N1, followed by DT, ST, DC, and SC (α  =  .05). The surface area was largest in DT, followed by N1, ST, DC, and SC. Surface area engaged in cortical bone, however, was the greatest in N1. The surface area of mini-implants had positive correlation with stability. Among commercial designs, both added tapering and double threading improved stability. N1 was the most stable design within this research design. The new design has the potential to be clinically superior; it has enhanced stability and there is diminished risk of endangering nearby anatomic structures during placement and orthodontic treatment, but the design requires refinements to reduce insertion torque to avoid clinical difficulty and patient discomfort.

Online discussion groups for bulimia nervosa: an inductive approach to Internet-based communication between patients.

PubMed

Wesemann, Dorette; Grunwald, Martin

2008-09-01

Online discussion forums are often used by people with eating disorders. This study analyses 2,072 threads containing a total of 14,903 postings from an unmoderated German "prorecovery" forum for persons suffering from bulimia nervosa (www.ab-server.de) during the period from October 2004 to May 2006. The threads were inductively analyzed for underlying structural types, and the various types found were then analyzed for differences in temporal and quantitative parameters. Communication in the online discussion forum occurred in three types of thread: (1) problem-oriented threads (78.8% of threads), (2) communication-oriented threads (15.3% of threads), and (3) metacommunication threads (2.6% of threads). Metacommunication threads contained significantly more postings than problem-oriented and communication-oriented threads, and they were viewed significantly more often. Moreover, there are temporal differences between the structural types. Topics relating to active management of the disorder receive great attention in prorecovery forums. (c) 2008 by Wiley Periodicals, Inc.

Rapid and reliable protein structure determination via chemical shift threading.

PubMed

Hafsa, Noor E; Berjanskii, Mark V; Arndt, David; Wishart, David S

2018-01-01

Protein structure determination using nuclear magnetic resonance (NMR) spectroscopy can be both time-consuming and labor intensive. Here we demonstrate how chemical shift threading can permit rapid, robust, and accurate protein structure determination using only chemical shift data. Threading is a relatively old bioinformatics technique that uses a combination of sequence information and predicted (or experimentally acquired) low-resolution structural data to generate high-resolution 3D protein structures. The key motivations behind using NMR chemical shifts for protein threading lie in the fact that they are easy to measure, they are available prior to 3D structure determination, and they contain vital structural information. The method we have developed uses not only sequence and chemical shift similarity but also chemical shift-derived secondary structure, shift-derived super-secondary structure, and shift-derived accessible surface area to generate a high quality protein structure regardless of the sequence similarity (or lack thereof) to a known structure already in the PDB. The method (called E-Thrifty) was found to be very fast (often < 10 min/structure) and to significantly outperform other shift-based or threading-based structure determination methods (in terms of top template model accuracy)-with an average TM-score performance of 0.68 (vs. 0.50-0.62 for other methods). Coupled with recent developments in chemical shift refinement, these results suggest that protein structure determination, using only NMR chemical shifts, is becoming increasingly practical and reliable. E-Thrifty is available as a web server at http://ethrifty.ca .

Secure Computer System: Unified Exposition and Multics Interpretation

DTIC Science & Technology

1976-03-01

prearranged code to semaphore critical information to an undercleared subject/process. Neither of these topics is directly addressed by the mathematical...FURTHER CONSIDERATIONS. RULES OF OPERATION FOR A SECURE MULTICS Kernel primitives for a secure Multics will be derived from a higher level user...the Multics architecture as little as possible; this will account to a large extent for radical differences in form between actual kernel primitives

Two years' outcome of thread lifting with absorbable barbed PDO threads: Innovative score for objective and subjective assessment.

PubMed

Ali, Yasser Helmy

2018-02-01

Thread-lifting rejuvenation procedures have evolved again, with the development of absorbable threads. Although they have gained popularity among plastic surgeons and dermatologists, very few articles have been written in literature about absorbable threads. This study aims to evaluate two years' outcome of thread lifting using absorbable barbed threads for facial rejuvenation. Prospective comparative stud both objectively and subjectively and follow-up assessment for 24 months. Thread lifting for face rejuvenation has significant long-lasting effects that include skin lifting from 3-10 mm and high degree of patients' satisfaction with less incidence rate of complications, about 4.8%. Augmented results are obtained when thread lifting is combined with other lifting and rejuvenation modalities. Significant facial rejuvenation is achieved by thread lifting and highly augmented results are observed when they are combined with Botox, fillers, and/or platelet rich plasma (PRP) rejuvenations.

Thread gauge for tapered threads

DOEpatents

Brewster, Albert L.

1994-01-11

The thread gauge permits the user to determine the pitch diameter of tapered threads at the intersection of the pitch cone and the end face of the object being measured. A pair of opposed anvils having lines of threads which match the configuration and taper of the threads on the part being measured are brought into meshing engagement with the threads on opposite sides of the part. The anvils are located linearly into their proper positions by stop fingers on the anvils that are brought into abutting engagement with the end face of the part. This places predetermined reference points of the pitch cone of the thread anvils in registration with corresponding points on the end face of the part being measured, resulting in an accurate determination of the pitch diameter at that location. The thread anvils can be arranged for measuring either internal or external threads.

Thread gauge for tapered threads

DOEpatents

Brewster, A.L.

1994-01-11

The thread gauge permits the user to determine the pitch diameter of tapered threads at the intersection of the pitch cone and the end face of the object being measured. A pair of opposed anvils having lines of threads which match the configuration and taper of the threads on the part being measured are brought into meshing engagement with the threads on opposite sides of the part. The anvils are located linearly into their proper positions by stop fingers on the anvils that are brought into abutting engagement with the end face of the part. This places predetermined reference points of the pitch cone of the thread anvils in registration with corresponding points on the end face of the part being measured, resulting in an accurate determination of the pitch diameter at that location. The thread anvils can be arranged for measuring either internal or external threads. 13 figures.

CNT coated thread micro-electro-mechanical system for finger proprioception sensing

NASA Astrophysics Data System (ADS)

Shafi, A. A.; Wicaksono, D. H. B.

2017-04-01

In this paper, we aim to fabricate cotton thread based sensor for proprioceptive application. Cotton threads are utilized as the structural component of flexible sensors. The thread is coated with multi-walled carbon nanotube (MWCNT) dispersion by using facile conventional dipping-drying method. The electrical characterization of the coated thread found that the resistance per meter of the coated thread decreased with increasing the number of dipping. The CNT coated thread sensor works based on piezoresistive theory in which the resistance of the coated thread changes when force is applied. This thread sensor is sewed on glove at the index finger between middle and proximal phalanx parts and the resistance change is measured upon grasping mechanism. The thread based microelectromechanical system (MEMS) enables the flexible sensor to easily fit perfectly on the finger joint and gives reliable response as proprioceptive sensing.

Universal Common Communication Substrate (UCCS) Specification; Universal Common Communication Substrate (UCCS) Implementation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Universal Common Communication Substrate (UCCS) is a low-level communication substrate that exposes high-performance communication primitives, while providing network interoperability. It is intended to support multiple upper layer protocol (ULPs) or programming models including SHMEM,UPC,Titanium,Co-Array Fortran,Global Arrays,MPI,GASNet, and File I/O. it provides various communication operations including one-sided and two-sided point-to-point, collectives, and remote atomic operations. In addition to operations for ULPs, it provides an out-of-band communication channel required typically required to wire-up communication libraries.

Family structure and dynamics in DePalma's horror films.

PubMed

Gordon, N G

1983-01-01

An analysis of the familial relationships in Brian DePalma's five major horror films reveals a persistent unconscious fantasy formation involving the nuclear family. These single-parent, only-child families are all tragically destroyed because of an inability to adequately mourn the absent parent. Although the asexual young adults in the films are spared the completely disastrous effects of madness and violence, they are still psychologically traumatized. This hidden subtextual theme involving the family parallels DePalma's bleak view of authority figures outside the home, as well as American society in general. Adequate identity formation requires that people both inside and outside the family accept the adolescent as a separate person. The grim psychological truth threading its way throughout DePalma's horror films is that these young adults are psychically devastated by the effects of a primitive, fused symbiotic relationship in interaction with a society that does not provide an adequate role for the developing person. Consequently, their attempt to psychologically move outside the family, which includes the maturation of their sexuality, results in the destruction of the family itself.

Design of internal screw thread measuring device based on the Three-Line method principle

NASA Astrophysics Data System (ADS)

Hu, Dachao; Chen, Jianguo

2010-08-01

In accordance with the principle of Three-Line, this paper analyze the correlation of every main parameter of internal screw thread, and then designed a device to measure the main parameters of internal screw thread. Internal thread parameters, such as the pitch diameter, thread angle and screw-pitch of common screw thread, terraced screw thread, zigzag screw thread were obtained through calculation and measurement. The practical applications have proved that this device is convenience to use, and the measurements have a high accuracy. Meanwhile, the application for the patent of invention has been accepted by the Patent Office (Filing number: 200710044081.5).

A New Operating System for Security Tagged Architecture Hardware in Support of Multiple Independent Levels of Security (MILS) Compliant System

DTIC Science & Technology

2014-04-01

important data structures of RTEMS are introduced. Section 3.2.2 discusses the problems we found in RTEMS that may cause security vulnerabilities...the important data structures in RTEMS: Object, which is a critical data structure in the SCORE, tasks threads. Approved for Public Release...these important system codes. The example code shows a possibility that a user can delete a system thread. Therefore, in order to protect system

General and specific gypsy moth predators

Treesearch

Ronald M. Weseloh

1991-01-01

General larval predators of low-density gypsy moth, Lymantria dispar (L.), populations have been assessed by exposing caterpillars tethered by threads. Most mortality occurred on tree trunks and in leaf litter.

3D finite element analysis of changes in stress levels and distributions for an osseointegrated implant after vertical bone loss.

PubMed

Yoon, Kyung-Ho; Kim, Su-Gwan; Lee, Jeong-Hoon; Suh, Seung-Woo

2011-10-01

The effect of stress levels and distributions around the internal nonsubmerged type implants after vertical bone resorption was investigated in this study. An HSII implant was placed in 4 cylindrical alveolar bone models with differing degrees of thread exposures. The load applied to each implant was von Mises stress and principal stress, 250 N in axial direction and 30 degrees lateral pressure. The difference in the load between the bone and the connective portion of the implant was obtained using ANSYS analysis. Bone loss in the cervical area of the implant was more obvious under lateral pressure. When more threads were exposed, bone level decreased and the maximum load applied on the fixture increased. It was concluded that higher bone level has a biomechanical advantage with respect to stress concentration.

Versatility of `hemorheologic fitness' according to exercise intensity: emphasis on the "healthy primitive lifestyle"

NASA Astrophysics Data System (ADS)

Brun, Jean-Frédéric; Varlet-Marie, Emmanuelle; Chevance, Guillaume; Pollatz, Marion; Fedou, Christine; de Mauverger, Eric Raynaud

2014-05-01

We recently proposed a unifying hypothesis to reconcile unexpected findings in exercise hemorheology and the classical concepts of "hemorheologic fitness" and the "triphasic effects of exercise", based on the "healthy primitive lifestyle" paradigm. This paradigm assumes that evolution has selected genetic polymorphisms leading to insulin resistance as an adaptative strategy to cope with continuous low intensity physical activity and a special alimentation moderately high in protein, rich in low glycemic index carbohydrates, and poor in saturated fat. According to this protocol the true physiological picture would be that of an individual whose exercise and nutritional habits are close from this lifestyle, both sedentary subjects and trained athletes representing situations on the edge of this model. Unfortunately samples of people truly adhering to this ancestral lifestyle are hard to obtain. In order to address this picture we tried to compare databases obtained with our preceding published studies. As a model of the "healthy primitive lifestyle" we selected patients trained at low intensity (LI) and given an advice of protein intake around 1.2 g/kg/day. Results show a continuum for plasma viscosity which seems to be lower in athletes than LI-trained and even more sedentaries. When sedentary subjects become obese the most obvious characteristic is an increase in red blood cell (RBC) aggregation correlated to the size of fat stores. It is clear that 3 months of LI are not a perfect model of "healthy primitive lifestyle", but these data suggest that the most important effect of LI regular exercise is to decrease plasma viscosity and that sedentarity increases RBC aggregation mostly when it results in increased fat storage.

On the zero-Rossby limit for the primitive equations of the atmosphere*

NASA Astrophysics Data System (ADS)

Chen, Gui-Qiang; Zhang, Ping

2001-09-01

The zero-Rossby limit for the primitive equations governing atmospheric motions is analysed. The limit is important in geophysics for large-scale models (cf Lions 1996 Int. Conf. IAM 95 (Hamburg 1995) (Math. Res. vol 87) (Berlin: Akademie) pp 177-212) and is in the level of the zero relaxation limit for nonlinear partial differential equations (cf Chen et al 1994 Commun. Pure Appl. Math. 47 787-830). It is proved that, if the initial data appropriately approximate data of geostrophic type, the corresponding solutions of the simplified primitive equations approximate the solutions of the quasigeostrophic equations with order ɛ accuracy as the Rossby number ɛ goes to zero.

Thread angle dependency on flame spread shape over kenaf/polyester combined fabric

NASA Astrophysics Data System (ADS)

Azahari Razali, Mohd; Sapit, Azwan; Nizam Mohammed, Akmal; Nor Anuar Mohamad, Md; Nordin, Normayati; Sadikin, Azmahani; Faisal Hushim, Mohd; Jaat, Norrizam; Khalid, Amir

2017-09-01

Understanding flame spread behavior is crucial to Fire Safety Engineering. It is noted that the natural fiber exhibits different flame spread behavior than the one of the synthetic fiber. This different may influences the flame spread behavior over combined fabric. There is a research has been done to examined the flame spread behavior over kenaf/polyester fabric. It is seen that the flame spread shape is dependent on the thread angle dependency. However, the explanation of this phenomenon is not described in detail in that research. In this study, explanation about this phenomenon is given in detail. Results show that the flame spread shape is dependent on the position of synthetic thread. For thread angle, θ = 0°, the polyester thread is breaking when the flame approach to the thread and the kenaf thread tends to move to the breaking direction. This behavior produces flame to be ‘V’ shape. However, for thread angle, θ = 90°, the polyester thread melts while the kenaf thread decomposed and burned. At this angle, the distance between kenaf threads remains constant as flame approaches.

The effect of thread pattern upon implant osseointegration.

PubMed

Abuhussein, Heba; Pagni, Giorgio; Rebaudi, Alberto; Wang, Hom-Lay

2010-02-01

Implant design features such as macro- and micro-design may influence overall implant success. Limited information is currently available. Therefore, it is the purpose of this paper to examine these factors such as thread pitch, thread geometry, helix angle, thread depth and width as well as implant crestal module may affect implant stability. A literature search was conducted using MEDLINE to identify studies, from simulated laboratory models, animal, to human, related to this topic using the keywords of implant thread, implant macrodesign, thread pitch, thread geometry, helix angle, thread depth, thread width and implant crestal module. The results showed how thread geometry affects the distribution of stress forces around the implant. A decreased thread pitch may positively influence implant stability. Excess helix angles in spite of a faster insertion may jeopardize the ability of implants to sustain axial load. Deeper threads seem to have an important effect on the stabilization in poorer bone quality situations. The addition of threads or microthreads up to the crestal module of an implant might provide a potential positive contribution on bone-to to-implant contact as well as on the preservation of marginal bone; nonetheless this remains to be determined. Appraising the current literature on this subject and combining existing data to verify the presence of any association between the selected characteristics may be critical in the achievement of overall implant success.

Method for molding threads in graphite panels

DOEpatents

Short, W.W.; Spencer, C.

1994-11-29

A graphite panel with a hole having a damaged thread is repaired by drilling the hole to remove all of the thread and making a new hole of larger diameter. A bolt with a lubricated thread is placed in the new hole and the hole is packed with graphite cement to fill the hole and the thread on the bolt. The graphite cement is cured, and the bolt is unscrewed therefrom to leave a thread in the cement which is at least as strong as that of the original thread. 8 figures.

Operating systems. [of computers

NASA Technical Reports Server (NTRS)

Denning, P. J.; Brown, R. L.

1984-01-01

A counter operating system creates a hierarchy of levels of abstraction, so that at a given level all details concerning lower levels can be ignored. This hierarchical structure separates functions according to their complexity, characteristic time scale, and level of abstraction. The lowest levels include the system's hardware; concepts associated explicitly with the coordination of multiple tasks appear at intermediate levels, which conduct 'primitive processes'. Software semaphore is the mechanism controlling primitive processes that must be synchronized. At higher levels lie, in rising order, the access to the secondary storage devices of a particular machine, a 'virtual memory' scheme for managing the main and secondary memories, communication between processes by way of a mechanism called a 'pipe', access to external input and output devices, and a hierarchy of directories cataloguing the hardware and software objects to which access must be controlled.

The measure method of internal screw thread and the measure device design

NASA Astrophysics Data System (ADS)

Hu, Dachao; Chen, Jianguo

2008-12-01

In accordance with the principle of Three-Line, this paper analyzed the correlation of every main parameter of internal screw thread, and then designed a device to measure the main parameters of internal screw thread. Basis on the measured value and corresponding formula calculation, we can get the internal thread parameters, such as the pitch diameter, thread angle and screw-pitch of common screw thread, terraced screw thread, zigzag screw thread and some else. The practical application has proved that this operation of this device is convenience, and the measured dates have a high accuracy. Meanwhile, the application of this device's patent of invention is accepted by the Patent Office. (The filing number: 200710044081.5)

Insertion tube methods and apparatus

DOEpatents

Casper, William L.; Clark, Don T.; Grover, Blair K.; Mathewson, Rodney O.; Seymour, Craig A.

2007-02-20

A drill string comprises a first drill string member having a male end; and a second drill string member having a female end configured to be joined to the male end of the first drill string member, the male end having a threaded portion including generally square threads, the male end having a non-threaded extension portion coaxial with the threaded portion, and the male end further having a bearing surface, the female end having a female threaded portion having corresponding female threads, the female end having a non-threaded extension portion coaxial with the female threaded portion, and the female end having a bearing surface. Installation methods, including methods of installing instrumented probes are also provided.

Subsurface drill string

DOEpatents

Casper, William L [Rigby, ID; Clark, Don T [Idaho Falls, ID; Grover, Blair K [Idaho Falls, ID; Mathewson, Rodney O [Idaho Falls, ID; Seymour, Craig A [Idaho Falls, ID

2008-10-07

A drill string comprises a first drill string member having a male end; and a second drill string member having a female end configured to be joined to the male end of the first drill string member, the male end having a threaded portion including generally square threads, the male end having a non-threaded extension portion coaxial with the threaded portion, and the male end further having a bearing surface, the female end having a female threaded portion having corresponding female threads, the female end having a non-threaded extension portion coaxial with the female threaded portion, and the female end having a bearing surface. Installation methods, including methods of installing instrumented probes are also provided.

CMS event processing multi-core efficiency status

NASA Astrophysics Data System (ADS)

Jones, C. D.; CMS Collaboration

2017-10-01

In 2015, CMS was the first LHC experiment to begin using a multi-threaded framework for doing event processing. This new framework utilizes Intel’s Thread Building Block library to manage concurrency via a task based processing model. During the 2015 LHC run period, CMS only ran reconstruction jobs using multiple threads because only those jobs were sufficiently thread efficient. Recent work now allows simulation and digitization to be thread efficient. In addition, during 2015 the multi-threaded framework could run events in parallel but could only use one thread per event. Work done in 2016 now allows multiple threads to be used while processing one event. In this presentation we will show how these recent changes have improved CMS’s overall threading and memory efficiency and we will discuss work to be done to further increase those efficiencies.

Morphological decomposition of 2-D binary shapes into convex polygons: a heuristic algorithm.

PubMed

Xu, J

2001-01-01

In many morphological shape decomposition algorithms, either a shape can only be decomposed into shape components of extremely simple forms or a time consuming search process is employed to determine a decomposition. In this paper, we present a morphological shape decomposition algorithm that decomposes a two-dimensional (2-D) binary shape into a collection of convex polygonal components. A single convex polygonal approximation for a given image is first identified. This first component is determined incrementally by selecting a sequence of basic shape primitives. These shape primitives are chosen based on shape information extracted from the given shape at different scale levels. Additional shape components are identified recursively from the difference image between the given image and the first component. Simple operations are used to repair certain concavities caused by the set difference operation. The resulting hierarchical structure provides descriptions for the given shape at different detail levels. The experiments show that the decomposition results produced by the algorithm seem to be in good agreement with the natural structures of the given shapes. The computational cost of the algorithm is significantly lower than that of an earlier search-based convex decomposition algorithm. Compared to nonconvex decomposition algorithms, our algorithm allows accurate approximations for the given shapes at low coding costs.

Tear glucose detection combining microfluidic thread based device, amperometric biosensor and microflow injection analysis.

PubMed

Agustini, Deonir; Bergamini, Márcio F; Marcolino-Junior, Luiz Humberto

2017-12-15

The tear glucose analysis is an important alternative for the indirect, simple and less invasive monitoring of blood glucose levels. However, the high cost and complex manufacturing process of tear glucose analyzers combined with the need to exchange the sensor after each analysis in the disposable tests prevent widespread application of the tear in glucose monitoring. Here, we present the integration of a biosensor made by the electropolymerization of poly(toluidine blue O) (PTB) and glucose oxidase (GOx) with an electroanalytical microfluidic device of easy assembly based on cotton threads, low cost materials and measurements by microflow injection analysis (µFIA) through passive pumping for performing tear glucose analyses in a simple, rapid and inexpensive way. A high stability between the analyses (RSD = 2.54%) and among the different systems (RSD = 3.13%) was obtained for the determination of glucose, in addition to a wide linear range between 0.075 and 7.5mmolL -1 and a limit of detection of 22.2µmolL -1 . The proposed method was efficiently employed in the determination of tear glucose in non-diabetic volunteers, obtaining a close correlation with their blood glucose levels, simplifying and reducing the costs of the analyses, making the tear glucose monitoring more accessible for the population. Copyright © 2017 Elsevier B.V. All rights reserved.

Multi-threading: A new dimension to massively parallel scientific computation

NASA Astrophysics Data System (ADS)

Nielsen, Ida M. B.; Janssen, Curtis L.

2000-06-01

Multi-threading is becoming widely available for Unix-like operating systems, and the application of multi-threading opens new ways for performing parallel computations with greater efficiency. We here briefly discuss the principles of multi-threading and illustrate the application of multi-threading for a massively parallel direct four-index transformation of electron repulsion integrals. Finally, other potential applications of multi-threading in scientific computing are outlined.

The DISCUS Hardware System,

DTIC Science & Technology

1982-07-01

blocks. DISCUS has no form of hardware synchronisation between the processors. The only synchronisation is at an operating system level. ;ach processor is... operations in global store so that semaphoring on global objects can be done correctly. Write Protect is used by the operating system for read-only...the appropriate operating system program. String Handling primitives . The Z8000 has a rich set of string primitives . However as we saw before if a

Influence of implantoplasty on stress distribution of exposed implants at different bone insertion levels.

PubMed

Tribst, João Paulo Mendes; Dal Piva, Amanda Maria de Oliveira; Shibli, Jamil Awad; Borges, Alexandre Luiz Souto; Tango, Rubens Nisie

2017-12-07

This study evaluated the effect of implantoplasty on different bone insertion levels of exposed implants. A model of the Bone Level Tapered implant (Straumann Institute, Waldenburg, Switzerland) was created through the Rhinoceros software (version 5.0 SR8, McNeel North America, Seattle, WA, USA). The abutment was fixed to the implant through a retention screw and a monolithic crown was modeled over a cementation line. Six models were created with increasing portions of the implant threads exposed: C1 (1 mm), C2 (2 mm), C3 (3 mm), C4 (4 mm), C5 (5 mm) and C6 (6 mm). The models were made in duplicates and one of each pair was used to simulate implantoplasty, by removing the threads (I1, I2, I3, I4, I5 and I6). The final geometry was exported in STEP format to ANSYS (ANSYS 15.0, ANSYS Inc., Houston, USA) and all materials were considered homogeneous, isotropic and linearly elastic. To assess distribution of stress forces, an axial load (300 N) was applied on the cusp. For the periodontal insert, the strains increased in the peri-implant region according to the size of the exposed portion and independent of the threads' presence. The difference between groups with and without implantoplasty was less than 10%. Critical values were found when the inserted portion was smaller than the exposed portion. In the exposed implants, the stress generated on the implant and retention screw was higher in the models that received implantoplasty. For the bone tissue, exposure of the implant's thread was a damaging factor, independent of implantoplasty. Implantoplasty treatment can be safely used to control peri-implantitis if at least half of the implant is still inserted in bone.

Assessing the Effect of Dental Implants Thread Design on Distribution of Stress in Impact Loadings Using Three Dimensional Finite Element Method

PubMed Central

I, Zarei; S, Khajehpour; A, Sabouri; AZ, Haghnegahdar; K, Jafari

2016-01-01

Statement of Problem: Impacts and accidents are considered as the main fac- tors in losing the teeth, so the analysis and design of the implants that they can be more resistant against impacts is very important. One of the important nu- merical methods having widespread application in various fields of engineering sciences is the finite element method. Among its wide applications, the study of distribution of power in complex structures can be noted. Objectives: The aim of this research was to assess the geometric effect and the type of implant thread on its performance; we also made an attempt to determine the created stress using finite element method. Materials and Methods: In this study, the three dimensional model of bone by using Cone Beam Computerized Tomography (CBCT) of the patient has been provided. The implants in this study are designed by Solid Works software. Loading is simulated in explicit dynamic, by struck of a rigid body with the speed of 1 mm/s to implant vertically and horizontally; and the maximum level of induced stress for the cortical and trabecular bone in the ANSYS Workbench software was calculated. Results: By considering the results of this study, it was identified that, among the designed samples, the maximum imposed stress in the cortical bone layer occurred in the first group (straight threads) and the maximum stress value in the trabecular bone layer and implant occurred in the second group (tapered threads). Conclusions: Due to the limitations of this study, the implants with more depth thread, because of the increased contact surface of the implant with the bone, caused more stability; also, the implant with smaller thread and shorter pitch length caused more stress to the bone. PMID:28959748

Assessing the Effect of Dental Implants Thread Design on Distribution of Stress in Impact Loadings Using Three Dimensional Finite Element Method.

PubMed

I, Zarei; S, Khajehpour; A, Sabouri; Az, Haghnegahdar; K, Jafari

2016-06-01

Impacts and accidents are considered as the main fac- tors in losing the teeth, so the analysis and design of the implants that they can be more resistant against impacts is very important. One of the important nu- merical methods having widespread application in various fields of engineering sciences is the finite element method. Among its wide applications, the study of distribution of power in complex structures can be noted. The aim of this research was to assess the geometric effect and the type of implant thread on its performance; we also made an attempt to determine the created stress using finite element method. In this study, the three dimensional model of bone by using Cone Beam Computerized Tomography (CBCT) of the patient has been provided. The implants in this study are designed by Solid Works software. Loading is simulated in explicit dynamic, by struck of a rigid body with the speed of 1 mm/s to implant vertically and horizontally; and the maximum level of induced stress for the cortical and trabecular bone in the ANSYS Workbench software was calculated. By considering the results of this study, it was identified that, among the designed samples, the maximum imposed stress in the cortical bone layer occurred in the first group (straight threads) and the maximum stress value in the trabecular bone layer and implant occurred in the second group (tapered threads). Due to the limitations of this study, the implants with more depth thread, because of the increased contact surface of the implant with the bone, caused more stability; also, the implant with smaller thread and shorter pitch length caused more stress to the bone.

Improved Screw-Thread Lock

NASA Technical Reports Server (NTRS)

Macmartin, Malcolm

1995-01-01

Improved screw-thread lock engaged after screw tightened in nut or other mating threaded part. Device does not release contaminating material during tightening of screw. Includes pellet of soft material encased in screw and retained by pin. Hammer blow on pin extrudes pellet into slot, engaging threads in threaded hole or in nut.

Method for molding threads in graphite panels

DOEpatents

Short, William W.; Spencer, Cecil

1994-01-01

A graphite panel (10) with a hole (11) having a damaged thread (12) is repaired by drilling the hole (11) to remove all of the thread and make a new hole (13) of larger diameter. A bolt (14) with a lubricated thread (17) is placed in the new hole (13) and the hole (13) is packed with graphite cement (16) to fill the hole and the thread on the bolt. The graphite cement (16) is cured, and the bolt is unscrewed therefrom to leave a thread (20) in the cement (16) which is at least as strong as that of the original thread (12).

Self-locking threaded fasteners

DOEpatents

Glovan, Ronald J.; Tierney, John C.; McLean, Leroy L.; Johnson, Lawrence L.

1996-01-01

A threaded fastener with a shape memory alloy (SMA) coatings on its threads is disclosed. The fastener has special usefulness in high temperature applications where high reliability is important. The SMA coated fastener is threaded into or onto a mating threaded part at room temperature to produce a fastened object. The SMA coating is distorted during the assembly. At elevated temperatures the coating tries to recover its original shape and thereby exerts locking forces on the threads. When the fastened object is returned to room temperature the locking forces dissipate. Consequently the threaded fasteners can be readily disassembled at room temperature but remains securely fastened at high temperatures. A spray technique is disclosed as a particularly useful method of coating of threads of a fastener with a shape memory alloy.

Improved full analytical polygon-based method using Fourier analysis of the three-dimensional affine transformation.

PubMed

Pan, Yijie; Wang, Yongtian; Liu, Juan; Li, Xin; Jia, Jia

2014-03-01

Previous research [Appl. Opt.52, A290 (2013)] has revealed that Fourier analysis of three-dimensional affine transformation theory can be used to improve the computation speed of the traditional polygon-based method. In this paper, we continue our research and propose an improved full analytical polygon-based method developed upon this theory. Vertex vectors of primitive and arbitrary triangles and the pseudo-inverse matrix were used to obtain an affine transformation matrix representing the spatial relationship between the two triangles. With this relationship and the primitive spectrum, we analytically obtained the spectrum of the arbitrary triangle. This algorithm discards low-level angular dependent computations. In order to add diffusive reflection to each arbitrary surface, we also propose a whole matrix computation approach that takes advantage of the affine transformation matrix and uses matrix multiplication to calculate shifting parameters of similar sub-polygons. The proposed method improves hologram computation speed for the conventional full analytical approach. Optical experimental results are demonstrated which prove that the proposed method can effectively reconstruct three-dimensional scenes.

Petrology of basaltic sills from ocean drilling program sites 794 and 797 in the Yamato Basin of the Japan Sea

NASA Technical Reports Server (NTRS)

Thy, P.

1992-01-01

The basaltic sills from ocean drilling program sites 794 and 797 in the Yamato Basin of the Japan Sea are characterized petrographically on the basis of a detailed study of the composition of relict phenocryst and groundmass phases. The systematic variation in the rock compositions is discussed. Results of 1-atm melting experiments on a relatively primitive basalt from site 797 are reported. The sills are found to constitute two distinct groups of suites: primitive, olivine-bearing suites with low potassium and primitive olivine-bearing to evolved, olivine-free suites with relatively high potassium. A pseudoinvariant reaction relationship between olivine and augite and magnetite is inferred. Complex magmatic and tectonic evolutions in the region, perhaps reflecting a transitional stage between subduction zone activity and back arc spreading, are suggested.

Method for Estimating Thread Strength Reduction of Damaged Parent Holes with Inserts

NASA Technical Reports Server (NTRS)

Johnson, David L.; Stratton, Troy C.

2005-01-01

During normal assembly and disassembly of bolted-joint components, thread damage and/or deformation may occur. If threads are overloaded, thread damage/deformation can also be anticipated. Typical inspection techniques (e.g. using GO-NO GO gages) may not provide adequate visibility of the extent of thread damage. More detailed inspection techniques have provided actual pitch-diameter profiles of damaged-hardware holes. A method to predict the reduction in thread shear-out capacity of damaged threaded holes has been developed. This method was based on testing and analytical modeling. Test samples were machined to simulate damaged holes in the hardware of interest. Test samples containing pristine parent-holes were also manufactured from the same bar-stock material to provide baseline results for comparison purposes. After the particular parent-hole thread profile was machined into each sample a helical insert was installed into the threaded hole. These samples were tested in a specially designed fixture to determine the maximum load required to shear out the parent threads. It was determined from the pristine-hole samples that, for the specific material tested, each individual thread could resist an average load of 3980 pounds. The shear-out loads of the holes having modified pitch diameters were compared to the ultimate loads of the specimens with pristine holes. An equivalent number of missing helical coil threads was then determined based on the ratio of shear-out loads for each thread configuration. These data were compared with the results from a finite element model (FEM). The model gave insights into the ability of the thread loads to redistribute for both pristine and simulated damage configurations. In this case, it was determined that the overall potential reduction in thread load-carrying capability in the hardware of interest was equal to having up to three fewer threads in the hole that bolt threads could engage. One- half of this potential reduction was due to local pitch-diameter variations and the other half was due to overall pitch-diameter enlargement beyond Class 2 fit. This result was important in that the thread shear capacity for this particular hardware design was the limiting structural capability. The details of the method development, including the supporting testing, data reduction and analytical model results comparison will be discussed hereafter.

Comparison of resin film infusion, resin transfer molding, and consolidation of textile preforms for primary aircraft structure

NASA Technical Reports Server (NTRS)

Suarez, J.; Dastin, S.

1992-01-01

Innovative design concepts and cost effective fabrication processes were developed for damage tolerant primary structures that can perform at a design ultimate strain level of 6000 micro inch/inch. Attention focused on the use of textile high performance fiber reinforcement concepts that provide improved damage tolerance and out-of-plane load capability, low cost resin film infusion (RFI) and resin transfer molding (RTM) processes, and thermoplastic forming concepts. The fabrication of wing 'Y' spars by four different materials and/or processes methods is described: fabricated using IM7 angle interlock 0 to 90 deg woven preforms with + or - 45 deg plies stitched with Toray high strength graphite thread and processed using RFI and 3501-6 epoxy; fabricated using G40-800 knitted/stitched preforms and processed using RFI and 3501-6 epoxy; fabricated using G40-800 knitted/stitched preforms using RTM and Tactix 123/H41 epoxy; and fabricated preforms using AS4(6K)/PEEK 150 g commingled angle interlock 0 to 90 deg woven preforms with + or - 45 deg commingled plies stitched using high strength graphite thread and processed by consolidation. Structural efficiency, processability, and acquisition cost are compared.

The research and development of the non-contact detection of the tubing internal thread with a line structured light

NASA Astrophysics Data System (ADS)

Hu, Yuanyuan; Xu, Yingying; Hao, Qun; Hu, Yao

2013-12-01

The tubing internal thread plays an irreplaceable role in the petroleum equipment. The unqualified tubing can directly lead to leakage, slippage and bring huge losses for oil industry. For the purpose of improving efficiency and precision of tubing internal thread detection, we develop a new non-contact tubing internal thread measurement system based on the laser triangulation principle. Firstly, considering that the tubing thread had a small diameter and relatively smooth surface, we built a set of optical system with a line structured light to irradiate the internal thread surface and obtain an image which contains the internal thread profile information through photoelectric sensor. Secondly, image processing techniques were used to do the edge detection of the internal thread from the obtained image. One key method was the sub-pixel technique which greatly improved the detection accuracy under the same hardware conditions. Finally, we restored the real internal thread contour information on the basis of laser triangulation method and calculated tubing thread parameters such as the pitch, taper and tooth type angle. In this system, the profile of several thread teeth can be obtained at the same time. Compared with other existing scanning methods using point light and stepper motor, this system greatly improves the detection efficiency. Experiment results indicate that this system can achieve the high precision and non-contact measurement of the tubing internal thread.

Measurement of Sound Speed in Thread

NASA Astrophysics Data System (ADS)

Saito, Shigemi; Shibata, Yasuhiro; Ichiki, Akira; Miyazaki, Akiho

2006-05-01

By employing thin wires, human hairs and threads, the measurement of sound speed in a thread whose diameter is smaller than 0.2 mm has been attempted. Preparing two cylindrical ceramic transducers with a 300 kHz resonance frequency, a perforated glass bead to be knotted by a sample thread is bonded to the center of the end surface of each transducer. After connecting these transducers with a sample thread, a receiving transducer is attached at a ceiling so as to hang another transmitting transducer with the thread. A glass bead is bonded to another end surface of the transmitting transducer so that tension, varied with a hanged plumb, can be applied to the sample thread. The time delay of the received signal relative to the transmitting pulse is measured while gradually shortening the thread. Sound speed is determined by the proportionality of time delay with thread length. Although the measured values for metallic wires are somewhat different from the values derived from the density and Young’s modulus cited in references, they are reproducible. The sound speed for human hairs of over twenty samples, which varies between 2000 and 2500 m/s, seems to depend on hair quality. Sound speed in a cotton thread is found to approach a constant value under large tension. An advanced measurement system available for uncut threads is also presented, where semi cylindrical transducers pinch the thread.

78 FR 79670 - Steel Threaded Rod From Thailand: Preliminary Determination of Sales at Less Than Fair Value and...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-31

... DEPARTMENT OF COMMERCE International Trade Administration [A-549-831] Steel Threaded Rod From... ``Department'') preliminarily determines that steel threaded rod from Thailand is being, or is likely to be... Investigation The merchandise covered by this investigation is steel threaded rod. Steel threaded rod is certain...

49 CFR 178.46 - Specification 3AL seamless aluminum cylinders.

Code of Federal Regulations, 2012 CFR

2012-10-01

... circular. (5) All openings must be threaded. Threads must comply with the following: (i) Each thread must be clean cut, even, without checks, and to gauge. (ii) Taper threads, when used, must conform to one of the following: (A) American Standard Pipe Thread (NPT) type, conforming to the requirements of NBS...

49 CFR 178.46 - Specification 3AL seamless aluminum cylinders.

Code of Federal Regulations, 2014 CFR

2014-10-01

... circular. (5) All openings must be threaded. Threads must comply with the following: (i) Each thread must be clean cut, even, without checks, and to gauge. (ii) Taper threads, when used, must conform to one of the following: (A) American Standard Pipe Thread (NPT) type, conforming to the requirements of NBS...

49 CFR 178.46 - Specification 3AL seamless aluminum cylinders.

Code of Federal Regulations, 2013 CFR

2013-10-01

... circular. (5) All openings must be threaded. Threads must comply with the following: (i) Each thread must be clean cut, even, without checks, and to gauge. (ii) Taper threads, when used, must conform to one of the following: (A) American Standard Pipe Thread (NPT) type, conforming to the requirements of NBS...

49 CFR 178.46 - Specification 3AL seamless aluminum cylinders.

Code of Federal Regulations, 2011 CFR

2011-10-01

... circular. (5) All openings must be threaded. Threads must comply with the following: (i) Each thread must be clean cut, even, without checks, and to gauge. (ii) Taper threads, when used, must conform to one of the following: (A) American Standard Pipe Thread (NPT) type, conforming to the requirements of NBS...

AN MHD AVALANCHE IN A MULTI-THREADED CORONAL LOOP

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hood, A. W.; Cargill, P. J.; Tam, K. V.

For the first time, we demonstrate how an MHD avalanche might occur in a multithreaded coronal loop. Considering 23 non-potential magnetic threads within a loop, we use 3D MHD simulations to show that only one thread needs to be unstable in order to start an avalanche even when the others are below marginal stability. This has significant implications for coronal heating in that it provides for energy dissipation with a trigger mechanism. The instability of the unstable thread follows the evolution determined in many earlier investigations. However, once one stable thread is disrupted, it coalesces with a neighboring thread andmore » this process disrupts other nearby threads. Coalescence with these disrupted threads then occurs leading to the disruption of yet more threads as the avalanche develops. Magnetic energy is released in discrete bursts as the surrounding stable threads are disrupted. The volume integrated heating, as a function of time, shows short spikes suggesting that the temporal form of the heating is more like that of nanoflares than of constant heating.« less

Self-locking threaded fasteners

DOEpatents

Glovan, R.J.; Tierney, J.C.; McLean, L.L.; Johnson, L.L.

1996-01-16

A threaded fastener with a shape memory alloy (SMA) coatings on its threads is disclosed. The fastener has special usefulness in high temperature applications where high reliability is important. The SMA coated fastener is threaded into or onto a mating threaded part at room temperature to produce a fastened object. The SMA coating is distorted during the assembly. At elevated temperatures the coating tries to recover its original shape and thereby exerts locking forces on the threads. When the fastened object is returned to room temperature the locking forces dissipate. Consequently the threaded fasteners can be readily disassembled at room temperature but remains securely fastened at high temperatures. A spray technique is disclosed as a particularly useful method of coating of threads of a fastener with a shape memory alloy. 13 figs.

Modeling self-organization of novel organic materials

NASA Astrophysics Data System (ADS)

Sayar, Mehmet

In this thesis, the structural organization of oligomeric multi-block molecules is analyzed by computational analysis of coarse-grained models. These molecules form nanostructures with different dimensionalities, and the nanostructured nature of these materials leads to novel structural properties at different length scales. Previously, a number of oligomeric triblock rodcoil molecules have been shown to self-organize into mushroom shaped noncentrosymmetric nanostructures. Interestingly, thin films of these molecules contain polar domains and a finite macroscopic polarization. However, the fully polarized state is not the equilibrium state. In the first chapter, by solving a model with dipolar and Ising-like short range interactions, we show that polar domains are stable in films composed of aggregates as opposed to isolated molecules. Unlike classical molecular systems, these nanoaggregates have large intralayer spacings (a ≈ 6 nm), leading to a reduction in the repulsive dipolar interactions that oppose polar order within layers. This enables the formation of a striped pattern with polar domains of alternating directions. The energies of the possible structures at zero temperature are computed exactly and results of Monte Carlo simulations are provided at non-zero temperatures. In the second chapter, the macroscopic polarization of such nanostructured films is analyzed in the presence of a short range surface interaction. The surface interaction leads to a periodic domain structure where the balance between the up and down domains is broken, and therefore films of finite thickness have a net macroscopic polarization. The polarization per unit volume is a function of film thickness and strength of the surface interaction. Finally, in chapter three, self-organization of organic molecules into a network of one dimensional objects is analyzed. Multi-block organic dendron rodcoil molecules were found to self-organize into supramolecular nanoribbons (threads) and form gels at very low concentrations. Here, the formation and structural properties of these networks are studied with Monte Carlo simulations. The model gelators can form intra and inter-thread bonds, and the threads have a finite stiffness. The results suggest that the high persistence length is a result of the interplay of thread stiffness and inter-thread interactions. Furthermore, this high persistence length enables the formation of networks at low concentrations.

CLOMP v1.5

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gyllenhaal, J.

CLOMP is the C version of the Livermore OpenMP benchmark developed to measure OpenMP overheads and other performance impacts due to threading. For simplicity, it does not use MPI by default but it is expected to be run on the resources a threaded MPI task would use (e.g., a portion of a shared memory compute node). Compiling with -DWITH_MPI allows packing one or more nodes with CLOMP tasks and having CLOMP report OpenMP performance for the slowest MPI task. On current systems, the strong scaling performance results for 4, 8, or 16 threads are of the most interest. Suggested weakmore » scaling inputs are provided for evaluating future systems. Since MPI is often used to place at least one MPI task per coherence or NUMA domain, it is recommended to focus OpenMP runtime measurements on a subset of node hardware where it is most possible to have low OpenMP overheads (e.g., within one coherence domain or NUMA domain).« less

Flexible horseshoe

DOEpatents

Ford, Donald F.

1985-01-01

A screw-on horseshoe formed from a plastic material is disclosed. A flex joint is provided that allows the horseshoe to expand and contract as pressure is applied to the horse's hoof, thereby reducing friction between the hoof and the shoe. The horseshoe also provides a lip portion projecting upwardly from a horseshoe base portion to protect the horse hoof wall from obstacles encountered during the movement of the horse. A novel screw having a double helix thread pattern including a high thread pattern and a low thread pattern is used to fasten the horseshoe to the horse's hoof without piercing the hoof wall. The screw includes a keyed recessed self-holding head that is complementary to, and therefore readily driven by, a power drill. A lightweight, yet wear-resistant, horseshoe that is readily attached to a horse's hoof with a minimum amount of labor and a minimum amount of damage to the hoof that can be constructed in many styles and sizes to match a large variety of horse uses is thus described.

Cribellate thread production in spiders: Complex processing of nano-fibres into a functional capture thread.

PubMed

Joel, Anna-Christin; Kappel, Peter; Adamova, Hana; Baumgartner, Werner; Scholz, Ingo

2015-11-01

Spider silk production has been studied intensively in the last years. However, capture threads of cribellate spiders employ an until now often unnoticed alternative of thread production. This thread in general is highly interesting, as it not only involves a controlled arrangement of three types of threads with one being nano-scale fibres (cribellate fibres), but also a special comb-like structure on the metatarsus of the fourth leg (calamistrum) for its production. We found the cribellate fibres organized as a mat, enclosing two parallel larger fibres (axial fibres) and forming the typical puffy structure of cribellate threads. Mat and axial fibres are punctiform connected to each other between two puffs, presumably by the action of the median spinnerets. However, this connection alone does not lead to the typical puffy shape of a cribellate thread. Removing the calamistrum, we found a functional capture thread still being produced, but the puffy shape of the thread was lost. Therefore, the calamistrum is not necessary for the extraction or combination of fibres, but for further processing of the nano-scale cribellate fibres. Using data from Uloborus plumipes we were able to develop a model of the cribellate thread production, probably universally valid for cribellate spiders. Copyright © 2015 Elsevier Ltd. All rights reserved.

Optimization of hetero-epitaxial growth for the threading dislocation density reduction of germanium epilayers

NASA Astrophysics Data System (ADS)

Chong, Haining; Wang, Zhewei; Chen, Chaonan; Xu, Zemin; Wu, Ke; Wu, Lan; Xu, Bo; Ye, Hui

2018-04-01

In order to suppress dislocation generation, we develop a "three-step growth" method to heteroepitaxy low dislocation density germanium (Ge) layers on silicon with the MBE process. The method is composed of 3 growth steps: low temperature (LT) seed layer, LT-HT intermediate layer as well as high temperature (HT) epilayer, successively. Threading dislocation density (TDD) of epitaxial Ge layers is measured as low as 1.4 × 106 cm-2 by optimizing the growth parameters. The results of Raman spectrum showed that the internal strain of heteroepitaxial Ge layers is tensile and homogeneous. During the growth of LT-HT intermediate layer, TDD reduction can be obtained by lowering the temperature ramping rate, and high rate deposition maintains smooth surface morphology in Ge epilayer. A mechanism based on thermodynamics is used to explain the TDD and surface morphological dependence on temperature ramping rate and deposition rate. Furthermore, we demonstrate that the Ge layer obtained can provide an excellent platform for III-V materials integrated on Si.

GaAsP solar cells on GaP/Si with low threading dislocation density

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yaung, Kevin Nay; Vaisman, Michelle; Lang, Jordan

2016-07-18

GaAsP on Si tandem cells represent a promising path towards achieving high efficiency while leveraging the Si solar knowledge base and low-cost infrastructure. However, dislocation densities exceeding 10{sup 8} cm{sup −2} in GaAsP cells on Si have historically hampered the efficiency of such approaches. Here, we report the achievement of low threading dislocation density values of 4.0–4.6 × 10{sup 6} cm{sup −2} in GaAsP solar cells on GaP/Si, comparable with more established metamorphic solar cells on GaAs. Our GaAsP solar cells on GaP/Si exhibit high open-circuit voltage and quantum efficiency, allowing them to significantly surpass the power conversion efficiency of previous devices. The resultsmore » in this work show a realistic path towards dual-junction GaAsP on Si cells with efficiencies exceeding 30%.« less

PICH and BLM limit histone association with anaphase centromeric DNA threads and promote their resolution

PubMed Central

Ke, Yuwen; Huh, Jae-Wan; Warrington, Ross; Li, Bing; Wu, Nan; Leng, Mei; Zhang, Junmei; Ball, Haydn L; Li, Bing; Yu, Hongtao

2011-01-01

Centromeres nucleate the formation of kinetochores and are vital for chromosome segregation during mitosis. The SNF2 family helicase PICH (Plk1-interacting checkpoint helicase) and the BLM (the Bloom's syndrome protein) helicase decorate ultrafine histone-negative DNA threads that link the segregating sister centromeres during anaphase. The functions of PICH and BLM at these threads are not understood, however. Here, we show that PICH binds to BLM and enables BLM localization to anaphase centromeric threads. PICH- or BLM-RNAi cells fail to resolve these threads in anaphase. The fragmented threads form centromeric-chromatin-containing micronuclei in daughter cells. Anaphase threads in PICH- and BLM-RNAi cells contain histones and centromere markers. Recombinant purified PICH has nucleosome remodelling activities in vitro. We propose that PICH and BLM unravel centromeric chromatin and keep anaphase DNA threads mostly free of nucleosomes, thus allowing these threads to span long distances between rapidly segregating centromeres without breakage and providing a spatiotemporal window for their resolution. PMID:21743438

Understanding thread properties for red blood cell antigen assays: weak ABO blood typing.

PubMed

Nilghaz, Azadeh; Zhang, Liyuan; Li, Miaosi; Ballerini, David R; Shen, Wei

2014-12-24

"Thread-based microfluidics" research has so far focused on utilizing and manipulating the wicking properties of threads to form controllable microfluidic channels. In this study we aim to understand the separation properties of threads, which are important to their microfluidic detection applications for blood analysis. Confocal microscopy was utilized to investigate the effect of the microscale surface morphologies of fibers on the thread's separation efficiency of red blood cells. We demonstrated the remarkably different separation properties of threads made using silk and cotton fibers. Thread separation properties dominate the clarity of blood typing assays of the ABO groups and some of their weak subgroups (Ax and A3). The microfluidic thread-based analytical devices (μTADs) designed in this work were used to accurately type different blood samples, including 89 normal ABO and 6 weak A subgroups. By selecting thread with the right surface morphology, we were able to build μTADs capable of providing rapid and accurate typing of the weak blood groups with high clarity.

Effect of Thread and Rotating Speed on Material Flow Behavior and Mechanical Properties of Friction Stir Lap Welding Joints

NASA Astrophysics Data System (ADS)

Ji, Shude; Li, Zhengwei; Zhou, Zhenlu; Wu, Baosheng

2017-10-01

This study focused on the effects of thread on hook and cold lap formation, lap shear property and impact toughness of alclad 2024-T4 friction stir lap welding (FSLW) joints. Except the traditional threaded pin tool (TR-tool), three new tools with different thread locations and orientations were designed. Results showed that thread significantly affected hook, cold lap morphologies and lap shear properties. The tool with tip-threaded pin (T-tool) fabricated joint with flat hook and cold lap, which resulted in shear fracture mode. The tools with bottom-threaded pin (B-tool) eliminated the hook. The tool with reverse-threaded pin (R-tool) widened the stir zone width. When using configuration A, the joints fabricated by the three new tools showed higher failure loads than the joint fabricated by the TR-tool. The joint using the T-tool owned the optimum impact toughness. This study demonstrated the significance of thread during FSLW and provided a reference to optimize tool geometry.

Metal and transuranic records in mussel shells, byssal threads and tissues

NASA Astrophysics Data System (ADS)

Koide, Minoru; Lee, Dong Soo; Goldberg, Edward D.

1982-12-01

Bivalve shells offer several advantages over tissues for the monitoring of heavy metal pollutants in the marine environment. They are easier to handle and to store. The problem of whether to depurate the animals before analyses is avoided. The shells appear to be more sensitive to environmental heavy metals levels over the long term than do the soft parts. Of the substances examined (Cd, Cu, Zn, Pb, Ag, Ni, 238Pu and 239 + 240Pu) only Pb and Pu displayed a strong covariance between soft tissue and shell concentrations. There were strong correlations between metals in the shell but not in the soft tissues in general. The byssal threads, because of their enrichment of transuranic elements and of their ease in handling, may be useful in monitoring these metals. A very weak discharge of 238Pu to marine waters adjacent to a nuclear reactor was detected in the byssal threads of mussels.

Experimental studies on the influence of the degree of turbulence and of a turbulence thread on the compressible subsonic flow through flat compressor cascades

NASA Technical Reports Server (NTRS)

Barsun, K.

1978-01-01

The measurements revealed that at low Reynolds numbers the profile loss is considerably reduced both by the increased degree of turbulence and by a turbulence thread, while it is somewhat increased at high Reynolds numbers, and that a profile loss reduction is connected with an increase in deflection and in pressure shift. The turbulence generator is most effective on the one hand in the middle of the operating range of the cascades, and on the other at very high Mach numbers together with a large angle of incidence.

Origin and evolution of primitive melts from the Debunscha Maar, Cameroon: Consequences for mantle source heterogeneity within the Cameroon Volcanic Line

NASA Astrophysics Data System (ADS)

Ngwa, Caroline N.; Hansteen, Thor H.; Devey, Colin W.; van der Zwan, Froukje M.; Suh, Cheo E.

2017-09-01

Debunscha Maar is a monogenetic volcano forming part of the Mt. Cameroon volcanic field, located within the Cameroon Volcanic Line (CVL). Partly glassy cauliflower bombs have primitive basanite-picrobasalt compositions and contain abundant normally and reversely zoned olivine (Fo 77-87) and clinopyroxene phenocrysts. Naturally quenched melt inclusions in the most primitive olivine phenocrysts show compositions which, when corrected for post-entrapment modification, cover a wide range from basanite to alkali basalt (MgO 6.9-11.7 wt%), and are generally more primitive than the matrix glasses (MgO 5.0-5.5 wt%) and only partly fall on a common liquid line of descent with the bulk rock samples and matrix glasses. Melt inclusion trace element compositions lie on two distinct geochemical trends: one (towards high Ba/Nb) is thought to represent the effect of various proportions of anhydrous lherzolite and amphibole-bearing peridotite in the source, while the other (for example, high La/Y) reflects variable degrees of partial melting. Comparatively low fractionation-corrected CaO in the melt inclusions with the highest La/Y suggests minor involvement of a pyroxenite source component that is only visible at low degrees of melting. Most of the samples show elevated Gd/Yb, indicating up to 8% garnet in the source. The range of major and trace elements represented by the melt inclusions covers the complete geochemical range given by basalts from different volcanoes of the Cameroon volcanic line, indicating that geochemical signatures that were previously thought to be volcano-specific in fact are probably present under all volcanoes. Clinopyroxene-melt barometry strongly indicates repeated mixing of compositionally diverse melts within the upper mantle at 830 ± 170 MPa prior to eruption. Mantle potential temperatures estimated for the primitive melt inclusions suggest that the thermal influence of a mantle plume is not required to explain the magma petrogenesis.

DistributedFBA.jl: High-level, high-performance flux balance analysis in Julia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Heirendt, Laurent; Thiele, Ines; Fleming, Ronan M. T.

Flux balance analysis and its variants are widely used methods for predicting steady-state reaction rates in biochemical reaction networks. The exploration of high dimensional networks with such methods is currently hampered by software performance limitations. DistributedFBA.jl is a high-level, high-performance, open-source implementation of flux balance analysis in Julia. It is tailored to solve multiple flux balance analyses on a subset or all the reactions of large and huge-scale networks, on any number of threads or nodes. DistributedFBA.jl is a high-level, high-performance, open-source implementation of flux balance analysis in Julia. It is tailored to solve multiple flux balance analyses on amore » subset or all the reactions of large and huge-scale networks, on any number of threads or nodes.« less

DistributedFBA.jl: High-level, high-performance flux balance analysis in Julia

DOE PAGES

Heirendt, Laurent; Thiele, Ines; Fleming, Ronan M. T.

2017-01-16

Flux balance analysis and its variants are widely used methods for predicting steady-state reaction rates in biochemical reaction networks. The exploration of high dimensional networks with such methods is currently hampered by software performance limitations. DistributedFBA.jl is a high-level, high-performance, open-source implementation of flux balance analysis in Julia. It is tailored to solve multiple flux balance analyses on a subset or all the reactions of large and huge-scale networks, on any number of threads or nodes. DistributedFBA.jl is a high-level, high-performance, open-source implementation of flux balance analysis in Julia. It is tailored to solve multiple flux balance analyses on amore » subset or all the reactions of large and huge-scale networks, on any number of threads or nodes.« less

Structural Turnbuckle Bears Compressive or Tensile Loads

NASA Technical Reports Server (NTRS)

Bateman, W. A.; Lang, C. H.

1985-01-01

Column length adjuster based on turnbuckle principle. Device consists of internally and externally threaded bushing, threaded housing and threaded rod. Housing attached to one part and threaded rod attached to other part of structure. Turning double threaded bushing contracts or extends rod in relation to housing. Once adjusted, bushing secured with jamnuts. Device used for axially loaded members requiring length adjustment during installation.

Do dual-thread orthodontic mini-implants improve bone/tissue mechanical retention?

PubMed

Lin, Yang-Sung; Chang, Yau-Zen; Yu, Jian-Hong; Lin, Chun-Li

2014-12-01

The aim of this study was to understand whether the pitch relationship between micro and macro thread designs with a parametrical relationship in a dual-thread mini-implant can improve primary stability. Three types of mini-implants consisting of single-thread (ST) (0.75 mm pitch in whole length), dual-thread A (DTA) with double-start 0.375 mm pitch, and dual-thread B (DTB) with single-start 0.2 mm pitch in upper 2-mm micro thread region for performing insertion and pull-out testing. Histomorphometric analysis was performed in these specimens in evaluating peri-implant bone defects using a non-contact vision measuring system. The maximum inserted torque (Tmax) in type DTA was found to be the smallest significantly, but corresponding values found no significant difference between ST and DTB. The largest pull-out strength (Fmax) in the DTA mini-implant was found significantly greater than that for the ST mini-implant regardless of implant insertion orientation. Mini-implant engaged the cortical bone well as observed in ST and DTA types. Dual-thread mini-implant with correct micro thread pitch (parametrical relationship with macro thread pitch) in the cortical bone region can improve primary stability and enhanced mechanical retention.

Three-dimensional optimization and sensitivity analysis of dental implant thread parameters using finite element analysis.

PubMed

Geramizadeh, Maryam; Katoozian, Hamidreza; Amid, Reza; Kadkhodazadeh, Mahdi

2018-04-01

This study aimed to optimize the thread depth and pitch of a recently designed dental implant to provide uniform stress distribution by means of a response surface optimization method available in finite element (FE) software. The sensitivity of simulation to different mechanical parameters was also evaluated. A three-dimensional model of a tapered dental implant with micro-threads in the upper area and V-shaped threads in the rest of the body was modeled and analyzed using finite element analysis (FEA). An axial load of 100 N was applied to the top of the implants. The model was optimized for thread depth and pitch to determine the optimal stress distribution. In this analysis, micro-threads had 0.25 to 0.3 mm depth and 0.27 to 0.33 mm pitch, and V-shaped threads had 0.405 to 0.495 mm depth and 0.66 to 0.8 mm pitch. The optimized depth and pitch were 0.307 and 0.286 mm for micro-threads and 0.405 and 0.808 mm for V-shaped threads, respectively. In this design, the most effective parameters on stress distribution were the depth and pitch of the micro-threads based on sensitivity analysis results. Based on the results of this study, the optimal implant design has micro-threads with 0.307 and 0.286 mm depth and pitch, respectively, in the upper area and V-shaped threads with 0.405 and 0.808 mm depth and pitch in the rest of the body. These results indicate that micro-thread parameters have a greater effect on stress and strain values.

The Study of Importance of the Balance Space Food -Storage Method -

NASA Astrophysics Data System (ADS)

Katayama, Naomi; Yamashita, Masamichi; Hashimoto, Hirofumi; Space Agriculture Task Force, J.

Providing foods to space crew is the important requirements to support long term manned space exploration. Foods fill not only physiological requirements to sustain life, but psychological needs for refreshment and joy during the long and hard mission to extraterrestrial planets. We designed joyful and healthy recipe with materials, which can be produced by the bio-regenerative agricultural system operated at limited resources available in Mars base, Moon base and spaceship. We need to think about how to use the storage food when we have the time of emergency. The pupa of the silkworm becomes the important nourishment source as protein and lipid. The silk thread uses it as clothing and cosmetics and medical supplies. However, we can use the silk thread as food as protein. The silk thread is mad of sericin and fibroin. The sericin is used for cosmetics mainly, but can make sheet food by mixing it with rice flour. We can make Japanese rolled sushi with this product. In addition, we can make spring roll and gyoza and shao-mai. As for the fibroin which is the subject of the silk thread, is to extract it high pressure heat; of the protein can powder it, and can use it as food. Even if there is the silk thread in this way after having made it clothes once, we can do it to food again. We can reuse the cotton thread as carbohydrates equally, too. We can use the wood as carbohydrates, also. Based upon the foregoing, we use the pupa of the silkworm as protein and lipid, and the silk thread as protein, and the cotton thread and wood as carbohydrates. It is recommended as healthy meal balance; Protein: Lipid: Carbohydrate ratio equal 15-20We succeeded to develop joyful and nutritious space recipe at the end. Since energy consumption for physical exercise activities under micro-or sub-gravity is less than the terrestrial case, choice of our space foods is essencial to suppress blood sugar level, and prevent the metabolic syndrome. Because of less need of agricultural resources at choosing ecological members from the lower ladder of the food chain, our space recipe could be a proposal to solve the food problem on Earth.

Cyclic Mario worlds — color-decomposition for one-loop QCD

NASA Astrophysics Data System (ADS)

Kälin, Gregor

2018-04-01

We present a new color decomposition for QCD amplitudes at one-loop level as a generalization of the Del Duca-Dixon-Maltoni and Johansson-Ochirov decomposition at tree level. Starting from a minimal basis of planar primitive amplitudes we write down a color decomposition that is free of linear dependencies among appearing primitive amplitudes or color factors. The conjectured decomposition applies to any number of quark flavors and is independent of the choice of gauge group and matter representation. The results also hold for higher-dimensional or supersymmetric extensions of QCD. We provide expressions for any number of external quark-antiquark pairs and gluons. [Figure not available: see fulltext.

SEM and fractography analysis of screw thread loosening in dental implants.

PubMed

Scarano, A; Quaranta, M; Traini, T; Piattelli, M; Piattelli, A

2007-01-01

Biological and technical failures of implants have already been reported. Mechanical factors are certainly of importance in implant failures, even if their exact nature has not yet been established. The abutment screw fracture or loosening represents a rare, but quite unpleasant failure. The aim of the present research is an analysis and structural examination of screw thread or abutment loosening compared with screw threads or abutment without loosening. The loosening of screw threads was compared to screw thread without loosening of three different implant systems; Branemark (Nobel Biocare, Gothenburg, Sweden), T.B.R. implant systems (Benax, Ancona, Italy) and Restore (Lifecore Biomedical, Chaska, Minnesota, USA). In this study broken screws were excluded. A total of 16 screw thread loosenings were observed (Group I) (4 Branemark, 4 T.B.R and 5 Restore), 10 screw threads without loosening were removed (Group II), and 6 screw threads as received by the manufacturer (unused) (Group III) were used as control (2 Branemark, 2 T.B.R and 2 Restore). The loosened abutment screws were retrieved and analyzed under SEM. Many alterations and deformations were present in concavities and convexities of screw threads in group I. No macroscopic alterations or deformations were observed in groups II and III. A statistical difference of the presence of microcracks were observed between screw threads with an abutment loosening and screw threads without an abutment loosening.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meijne, E.I.; van der Winden-van Groenewegen, R.J.; Ploemacher, R.E.

The sensitivity for x-irradiation of a series of hematopoietic stem cell populations has been determined. The most primitive cells identified, cells with marrow-repopulating ability (MRA), showed the highest degree of radioresistance. These MRA cells which generate many secondary day-twelve spleen colony-forming units (MRA(CFU-S-12)) or colony-forming units in culture (MRA(CFU-C)) in the marrow of primary recipients had Do values equal to 1.18 and 1.13 Gy, respectively. The more mature CFU-S-12 had intermediate radiosensitivity (Do = 0.94 Gy), whereas the less primitive CFU-S-7 were the most radiosensitive (Do = 0.71 Gy). The in vitro colony-forming precursor cells (CFU-C) showed low radiosensitivity. Thesemore » data clearly show that the most primitive hematopoietic stem cell measured is less sensitive to ionizing radiation than generally has been assumed on the basis of measurements on CFU-S-7 or CFU-S-12.« less

Origin of lead from green glass of Apollo 15426: a search for primitive lunar lead.

USGS Publications Warehouse

Tatsumoto, M.; Premo, W.R.; Unruh, D.M.

1987-01-01

A major obstacle in lunar U-Pb chronology is the elusiveness of the primary Pb isotopic composition and U/Pb ratio and therefore the Pb evolution for the early history of the moon. In an attempt to seek the primitive lunar Pb isotopoc composition, green glass from lunar clod 15426,49 was studied for U-Th-Pb systematics because it is extremely Mg-rich and known to be the most primitive among sampled lunar volcanic rocks. Because of the low Pb concentration and high U/Pb ratio observed for the interior, the initial Pb was poorly defined. Nevertheless, the data indicate that lunar Pb evolved in an environment with 238U/204Pb = 19-55, which is considerably lower than those for mare basalts (around 300) but higher than values for the Earth (6-8).-from Authors

A Moiré Pattern-Based Thread Counter

ERIC Educational Resources Information Center

Reich, Gary

2017-01-01

Thread count is a term used in the textile industry as a measure of how closely woven a fabric is. It is usually defined as the sum of the number of warp threads per inch (or cm) and the number of weft threads per inch. (It is sometimes confusingly described as the number of threads per square inch.) In recent years it has also become a subject of…

(Re)engineering Earth System Models to Expose Greater Concurrency for Ultrascale Computing: Practice, Experience, and Musings

NASA Astrophysics Data System (ADS)

Mills, R. T.

2014-12-01

As the high performance computing (HPC) community pushes towards the exascale horizon, the importance and prevalence of fine-grained parallelism in new computer architectures is increasing. This is perhaps most apparent in the proliferation of so-called "accelerators" such as the Intel Xeon Phi or NVIDIA GPGPUs, but the trend also holds for CPUs, where serial performance has grown slowly and effective use of hardware threads and vector units are becoming increasingly important to realizing high performance. This has significant implications for weather, climate, and Earth system modeling codes, many of which display impressive scalability across MPI ranks but take relatively little advantage of threading and vector processing. In addition to increasing parallelism, next generation codes will also need to address increasingly deep hierarchies for data movement: NUMA/cache levels, on node vs. off node, local vs. wide neighborhoods on the interconnect, and even in the I/O system. We will discuss some approaches (grounded in experiences with the Intel Xeon Phi architecture) for restructuring Earth science codes to maximize concurrency across multiple levels (vectors, threads, MPI ranks), and also discuss some novel approaches for minimizing expensive data movement/communication.

Automatic Thread-Level Parallelization in the Chombo AMR Library

DOE Office of Scientific and Technical Information (OSTI.GOV)

Christen, Matthias; Keen, Noel; Ligocki, Terry

2011-05-26

The increasing on-chip parallelism has some substantial implications for HPC applications. Currently, hybrid programming models (typically MPI+OpenMP) are employed for mapping software to the hardware in order to leverage the hardware?s architectural features. In this paper, we present an approach that automatically introduces thread level parallelism into Chombo, a parallel adaptive mesh refinement framework for finite difference type PDE solvers. In Chombo, core algorithms are specified in the ChomboFortran, a macro language extension to F77 that is part of the Chombo framework. This domain-specific language forms an already used target language for an automatic migration of the large number ofmore » existing algorithms into a hybrid MPI+OpenMP implementation. It also provides access to the auto-tuning methodology that enables tuning certain aspects of an algorithm to hardware characteristics. Performance measurements are presented for a few of the most relevant kernels with respect to a specific application benchmark using this technique as well as benchmark results for the entire application. The kernel benchmarks show that, using auto-tuning, up to a factor of 11 in performance was gained with 4 threads with respect to the serial reference implementation.« less

Characterisation of defects in p-GaN by admittance spectroscopy

NASA Astrophysics Data System (ADS)

Elsherif, O. S.; Vernon-Parry, K. D.; Evans-Freeman, J. H.; Airey, R. J.; Kappers, M.; Humphreys, C. J.

2012-08-01

Mg-doped GaN films have been grown on (0 0 0 1) sapphire using metal organic vapour phase epitaxy. Use of different buffer layer strategies caused the threading dislocation density (TDD) in the GaN to be either approximately 2×109 cm-2 or 1×1010 cm-2. Frequency-dependent capacitance and conductance measurements at temperatures up to 450 K have been used to study the electronic states associated with the Mg doping, and to determine how these are affected by the TDD. Admittance spectroscopy of the films finds a single impurity-related acceptor level with an activation energy of 160±10 meV for [Mg] of about 1×1019 cm-3, and 120±10 eV as the Mg precursor flux decreased. This level is thought to be associated with the Mg acceptor state. The TDD has no discernible effect on the trap detected by admittance spectroscopy. We compare these results with cathodoluminescence measurements reported in the literature, which reveal that most threading dislocations are non-radiative recombination centres, and discuss possible reasons why our admittance spectroscopy have not detected electrically active defects associated with threading dislocations.

Low-dislocation-density epitatial layers grown by defect filtering by self-assembled layers of spheres

DOEpatents

Wang, George T.; Li, Qiming

2013-04-23

A method for growing low-dislocation-density material atop a layer of the material with an initially higher dislocation density using a monolayer of spheroidal particles to bend and redirect or directly block vertically propagating threading dislocations, thereby enabling growth and coalescence to form a very-low-dislocation-density surface of the material, and the structures made by this method.

Trace element distributions in primitive achondrites

NASA Technical Reports Server (NTRS)

Davis, Andrew M.; Prinz, Martin; Weisberg, Michael K.

1993-01-01

The primitive achondrites have approximately chondritic bulk chemical composition but achondritic textures. Clayton et al. show that nine of these meteorites, the acapulcoites and the lodranites, have similar oxygen isotopic compositions. The acapulcoites appear to be highly metamorphosed, but undifferentiated meteorites of chondritic composition; whereas, the lodranites appear to have lost a feldspathic partial melt. In order to learn more about metamorphic processes and partial melt removal, we have measured the trace element compositions of constituent phases of a number of primitive achondrites by ion microprobe. We have analyzed two acapulcoites, Acapulco and ALH81261 (paired with ALH77081), and three londranites, Lodran, LEW88280, and MAC88177. In addition, we analyzed LEW88663, which has the bulk composition, mineral chemistry, and oxygen isotopic composition of L-chondrites, but is metal-free and has an achondrite texture; and Divnoe, a plagioclase-poor, olivine-rich primitive achondrite with an oxygen isotopic composition similar to that of the group IAB iron meteorites. These meteorites show a variety of REE patterns in their constituent phases, and there are consistent differences between acapulcoites and lodranites that are consistent with removal of a LREE- and Eu-enriched melt that is apparently responsible for the low plagioclase content of lodranites.

Ropes: Support for collective opertions among distributed threads

NASA Technical Reports Server (NTRS)

Haines, Matthew; Mehrotra, Piyush; Cronk, David

1995-01-01

Lightweight threads are becoming increasingly useful in supporting parallelism and asynchronous control structures in applications and language implementations. Recently, systems have been designed and implemented to support interprocessor communication between lightweight threads so that threads can be exploited in a distributed memory system. Their use, in this setting, has been largely restricted to supporting latency hiding techniques and functional parallelism within a single application. However, to execute data parallel codes independent of other threads in the system, collective operations and relative indexing among threads are required. This paper describes the design of ropes: a scoping mechanism for collective operations and relative indexing among threads. We present the design of ropes in the context of the Chant system, and provide performance results evaluating our initial design decisions.

Lack of ubiquitin immunoreactivities at both ends of neuropil threads. Possible bidirectional growth of neuropil threads.

PubMed

Iwatsubo, T; Hasegawa, M; Esaki, Y; Ihara, Y

1992-02-01

Immunocytochemically, neuropil threads (curly fibers) were investigated in the Alzheimer's disease brain using a confocal laser scanning fluorescence microscope by double labeling with tau/ubiquitin antibodies. Ubiquitin immunoreactivities were found to be lacking at one or both ends in more than 40% of tau-positive threads. Immunoelectron microscopy showed that bundles of paired helical filaments, which constitute neuropil threads, were positive for ubiquitin around their midportions, but often negative at their ends. Since it is reasonable to postulate that tau deposition as paired helical filaments precedes ubiquitination, the aforementioned observation suggests that the ends of the threads are newly formed portions, and thus the threads are often growing bidirectionally in small neuronal processes.

Low energy high pressure miniature screw valve

DOEpatents

Fischer, Gary J [Sandia Park, NM; Spletzer, Barry L [Albuquerque, NM

2006-12-12

A low energy high pressure screw valve having a valve body having an upper portion and a lower portion, said lower portion of said valve body defining an inlet flow passage and an outlet flow passage traversing said valve body to a valve seat, said upper portion of said valve body defining a cavity at said valve seat, a diaphragm restricting flow between said upper portion of said valve body and said lower portion, said diaphragm capable of engaging said valve seat to restrict fluid communication between said inlet passage and said outlet passage, a plunger within said cavity supporting said diaphragm, said plunger being capable of engaging said diaphragm with said valve seat at said inlet and outlet fluid passages, said plunger being in point contact with a drive screw having threads engaged with opposing threads within said upper portion of said valve body such engagement allowing motion of said drive screw within said valve body.

Gold thread implantation promotes hair growth in human and mice

PubMed Central

Kim, Jong-Hwan; Cho, Eun-Young; Kwon, Euna; Kim, Woo-Ho; Park, Jin-Sung; Lee, Yong-Soon

2017-01-01

Thread-embedding therapy has been widely applied for cosmetic purposes such as wrinkle reduction and skin tightening. Particularly, gold thread was reported to support connective tissue regeneration, but, its role in hair biology remains largely unknown due to lack of investigation. When we implanted gold thread and Happy Lift™ in human patient for facial lifting, we unexpectedly found an increase of hair regrowth in spite of no use of hair growth medications. When embedded into the depilated dorsal skin of mice, gold thread or polyglycolic acid (PGA) thread, similarly to 5% minoxidil, significantly increased the number of hair follicles on day 14 after implantation. And, hair re-growth promotion in the gold threadimplanted mice were significantly higher than that in PGA thread group on day 11 after depilation. In particular, the skin tissue of gold thread-implanted mice showed stronger PCNA staining and higher collagen density compared with control mice. These results indicate that gold thread implantation can be an effective way to promote hair re-growth although further confirmatory study is needed for more information on therapeutic mechanisms and long-term safety. PMID:29399026

Morphological Study of Insoluble Organic Matter Residues from Primitive

NASA Technical Reports Server (NTRS)

Changela, H. G.; Stroud, R. M.; Peeters, Z.; Nittler, L. R.; Alexander, C. M. O'D.; DeGregorio, B. T.; Cody, G. D.

2012-01-01

Insoluble organic matter (IOM) constitutes a major proportion, 70-99%, of the total organic carbon found in primitive chondrites [1, 2]. One characteristic morphological component of IOM is nanoglobules [3, 4]. Some nanoglobules exhibit large N-15 and D enrichments relative to solar values, indicating that they likely originated in the ISM or the outskirts of the protoplanetary disk [3]. A recent study of samples from the Tagish Lake meteorite with varying levels of hydrothermal alteration suggest that nanoglobule abundance decreases with increasing hydrothermal alteration [5]. The aim of this study is to further document the morphologies of IOM from a range of primitive chondrites in order to determine any correlation of morphology with petrographic grade and chondrite class that could constrain the formation and/or alteration mechanisms.

Understanding Single-Thread Meandering Rivers with High Sinuosity on Mars through Chemical Precipitation Experiments

NASA Astrophysics Data System (ADS)

Lim, Y.; Kim, W.

2015-12-01

Meandering rivers are extremely ubiquitous on Earth, yet it is only recently that single-thread experimental channels with low sinuosity have been created. In these recent experiments, as well as in natural rivers, vegetation plays a crucial role in maintaining a meandering pattern by adding cohesion to the bank and inhibiting erosion. The ancient, highly sinuous channels found on Mars are enigmatic because presumably vegetation did not exist on ancient Mars. Under the hypothesis that Martian meandering rivers formed by chemical precipitation on levees and flood plain deposits, we conducted carbonate flume experiments to investigate the formation and evolution of a single-thread meander pattern without vegetation. The flow recirculating in the flume is designed to accelerate chemical reactions - dissolution of limestone using CO2 gas to produce artificial spring water and precipitation of carbonates to increase cohesion- with precise control of water discharge, sediment discharge, and temperature. Preliminary experiments successfully created a single-thread meandering pattern through chemical processes. Carbonate deposits focused along the channel sides improved the bank stability and made them resistant to erosion, which led to a stream confined in a narrow path. The experimental channels showed lateral migration of the bend through cut bank and point bar deposits; intermittent floods created overbank flow and encouraged cut bank erosion, which enhanced lateral migration of the channel, while increase in sediment supply improved lateral point bar deposition, which balanced erosion and deposition rates. This mechanism may be applied to terrestrial single-thread and/or meandering rivers with little to no vegetation or before its introduction to Earth and also provide the link between meandering river records on Mars to changes in Martian surface conditions.

Scheduler for multiprocessor system switch with selective pairing

DOEpatents

Gara, Alan; Gschwind, Michael Karl; Salapura, Valentina

2015-01-06

System, method and computer program product for scheduling threads in a multiprocessing system with selective pairing of processor cores for increased processing reliability. A selective pairing facility is provided that selectively connects, i.e., pairs, multiple microprocessor or processor cores to provide one highly reliable thread (or thread group). The method configures the selective pairing facility to use checking provide one highly reliable thread for high-reliability and allocate threads to corresponding processor cores indicating need for hardware checking. The method configures the selective pairing facility to provide multiple independent cores and allocate threads to corresponding processor cores indicating inherent resilience.

Threaded biliary inside stents are a safe and effective therapeutic option in cases of malignant hilar obstruction.

PubMed

Inatomi, Osamu; Bamba, Shigeki; Shioya, Makoto; Mochizuki, Yosuke; Ban, Hiromitsu; Tsujikawa, Tomoyuki; Saito, Yasuharu; Andoh, Akira; Fujiyama, Yoshihide

2013-02-14

Although endoscopic biliary stents have been accepted as part of palliative therapy for cases of malignant hilar obstruction, the optimal endoscopic management regime remains controversial. In this study, we evaluated the safety and efficacy of placing a threaded stent above the sphincter of Oddi (threaded inside plastic stents, threaded PS) and compared the results with those of other stent types. Patients with malignant hilar obstruction, including those requiring biliary drainage for stent occlusion, were selected. Patients received either one of the following endoscopic indwelling stents: threaded PS, conventional plastic stents (conventional PS), or metallic stents (MS). Duration of stent patency and the incident of complication were compared in these patients. Forty-two patients underwent placement of endoscopic indwelling stents (threaded PS = 12, conventional PS = 17, MS = 13). The median duration of threaded PS patency was significantly longer than that of conventional PS patency (142 vs. 32 days; P = 0.04, logrank test). The median duration of threaded PS and MS patency was not significantly different (142 vs. 150 days, P = 0.83). Stent migration did not occur in any group. Among patients who underwent threaded PS placement as a salvage therapy after MS obstruction due to tumor ingrowth, the median duration of MS patency was significantly shorter than that of threaded PS patency (123 vs. 240 days). Threaded PS are safe and effective in cases of malignant hilar obstruction; moreover, it is a suitable therapeutic option not only for initial drainage but also for salvage therapy.

Combination Chemotherapy in Treating Patients With Non-Metastatic Extracranial Ewing Sarcoma

ClinicalTrials.gov

2018-02-09

Adult Supratentorial Primitive Neuroectodermal Tumor (PNET); Childhood Supratentorial Primitive Neuroectodermal Tumor; Ewing Sarcoma of Bone; Extraosseous Ewing Sarcoma; Extraosseous Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Localized Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Peripheral Primitive Neuroectodermal Tumor of the Kidney; Untreated Childhood Supratentorial Primitive Neuroectodermal Tumor

Lack of ubiquitin immunoreactivities at both ends of neuropil threads. Possible bidirectional growth of neuropil threads.

PubMed Central

Iwatsubo, T.; Hasegawa, M.; Esaki, Y.; Ihara, Y.

1992-01-01

Immunocytochemically, neuropil threads (curly fibers) were investigated in the Alzheimer's disease brain using a confocal laser scanning fluorescence microscope by double labeling with tau/ubiquitin antibodies. Ubiquitin immunoreactivities were found to be lacking at one or both ends in more than 40% of tau-positive threads. Immunoelectron microscopy showed that bundles of paired helical filaments, which constitute neuropil threads, were positive for ubiquitin around their midportions, but often negative at their ends. Since it is reasonable to postulate that tau deposition as paired helical filaments precedes ubiquitination, the aforementioned observation suggests that the ends of the threads are newly formed portions, and thus the threads are often growing bidirectionally in small neuronal processes. Images Figure 1 Figure 2 PMID:1310831

Fatigue acceptance test limit criterion for larger diameter rolled thread fasteners

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kephart, A.R.

1997-05-01

This document describes a fatigue lifetime acceptance test criterion by which studs having rolled threads, larger than 1.0 inches in diameter, can be assured to meet minimum quality attributes associated with a controlled rolling process. This criterion is derived from a stress dependent, room temperature air fatigue database for test studs having a 0.625 inch diameter threads of Alloys X-750 HTH and direct aged 625. Anticipated fatigue lives of larger threads are based on thread root elastic stress concentration factors which increase with increasing thread diameters. Over the thread size range of interest, a 30% increase in notch stress ismore » equivalent to a factor of five (5X) reduction in fatigue life. The resulting diameter dependent fatigue acceptance criterion is normalized to the aerospace rolled thread acceptance standards for a 1.0 inch diameter, 0.125 inch pitch, Unified National thread with a controlled Root radius (UNR). Testing was conducted at a stress of 50% of the minimum specified material ultimate strength, 80 Ksi, and at a stress ratio (R) of 0.10. Limited test data for fastener diameters of 1.00 to 2.25 inches are compared to the acceptance criterion. Sensitivity of fatigue life of threads to test nut geometry variables was also shown to be dependent on notch stress conditions. Bearing surface concavity of the compression nuts and thread flank contact mismatch conditions can significantly affect the fastener fatigue life. Without improved controls these conditions could potentially provide misleading acceptance data. Alternate test nut geometry features are described and implemented in the rolled thread stud specification, MIL-DTL-24789(SH), to mitigate the potential effects on fatigue acceptance data.« less

Toward a self-organizing pre-symbolic neural model representing sensorimotor primitives.

PubMed

Zhong, Junpei; Cangelosi, Angelo; Wermter, Stefan

2014-01-01

The acquisition of symbolic and linguistic representations of sensorimotor behavior is a cognitive process performed by an agent when it is executing and/or observing own and others' actions. According to Piaget's theory of cognitive development, these representations develop during the sensorimotor stage and the pre-operational stage. We propose a model that relates the conceptualization of the higher-level information from visual stimuli to the development of ventral/dorsal visual streams. This model employs neural network architecture incorporating a predictive sensory module based on an RNNPB (Recurrent Neural Network with Parametric Biases) and a horizontal product model. We exemplify this model through a robot passively observing an object to learn its features and movements. During the learning process of observing sensorimotor primitives, i.e., observing a set of trajectories of arm movements and its oriented object features, the pre-symbolic representation is self-organized in the parametric units. These representational units act as bifurcation parameters, guiding the robot to recognize and predict various learned sensorimotor primitives. The pre-symbolic representation also accounts for the learning of sensorimotor primitives in a latent learning context.

Toward a self-organizing pre-symbolic neural model representing sensorimotor primitives

PubMed Central

Zhong, Junpei; Cangelosi, Angelo; Wermter, Stefan

2014-01-01

The acquisition of symbolic and linguistic representations of sensorimotor behavior is a cognitive process performed by an agent when it is executing and/or observing own and others' actions. According to Piaget's theory of cognitive development, these representations develop during the sensorimotor stage and the pre-operational stage. We propose a model that relates the conceptualization of the higher-level information from visual stimuli to the development of ventral/dorsal visual streams. This model employs neural network architecture incorporating a predictive sensory module based on an RNNPB (Recurrent Neural Network with Parametric Biases) and a horizontal product model. We exemplify this model through a robot passively observing an object to learn its features and movements. During the learning process of observing sensorimotor primitives, i.e., observing a set of trajectories of arm movements and its oriented object features, the pre-symbolic representation is self-organized in the parametric units. These representational units act as bifurcation parameters, guiding the robot to recognize and predict various learned sensorimotor primitives. The pre-symbolic representation also accounts for the learning of sensorimotor primitives in a latent learning context. PMID:24550798

Development of an Instrument for Assessing the Effectiveness of Chemistry Classroom Teaching

NASA Astrophysics Data System (ADS)

Zheng, Changlong; Fu, Lihai; He, Peng

2014-04-01

Classroom teaching is a main frontier of the implementation of new curricular ideas in China. The study reported in this article is concerned with the effectiveness of system of classroom teaching (SCT) in chemistry lessons. According to the Systems Science theory, we took a macroscopic view on the SCT, arguing that SCT is a hierarchy of system, which includes class system, plate system, unit system, and primitive system. In this study, we focused on primitive system of classroom teaching (PrS)—the lowest level in a SCT. Using focus group interviews, this study investigated the variables related to the effectiveness of PrS. We found a total of 21 such variables. To identify the main factors underlying the effectiveness of PrS, we further used exploratory factor analysis and confirmatory factor analysis. We found five main factors: rational use of time, quality of teaching behavior chain, match degree, quality of using resource and technology, and rationality of primitive content. Based on these findings, we constructed an evaluation scale for assessing the effectiveness of primitive system of chemistry classroom teaching.

Wedges for ultrasonic inspection

DOEpatents

Gavin, Donald A.

1982-01-01

An ultrasonic transducer device is provided which is used in ultrasonic inspection of the material surrounding a threaded hole and which comprises a wedge of plastic or the like including a curved threaded surface adapted to be screwed into the threaded hole and a generally planar surface on which a conventional ultrasonic transducer is mounted. The plastic wedge can be rotated within the threaded hole to inspect for flaws in the material surrounding the threaded hole.

Apparatus for accurately preloading auger attachment means for frangible protective material

NASA Technical Reports Server (NTRS)

Wood, K. E.

1983-01-01

Apparatus for preloading a spring loaded threaded member is described. The apparatus is formed of three telescoping tubes. The innermost tube has means to prevent rotation of the threaded member. The middle tube is threadedly engaged with the threaded member and by axial movement applies a preload thereto. The outer tube engages a nut which may be rotated to retain the threaded member in axial position to maintain the preload.

Study of Thread Level Parallelism in a Video Encoding Application for Chip Multiprocessor Design

NASA Astrophysics Data System (ADS)

Debes, Eric; Kaine, Greg

2002-11-01

In media applications there is a high level of available thread level parallelism (TLP). In this paper we study the intra TLP in a video encoder. We show that a well-distributed highly optimized encoder running on a symmetric multiprocessor (SMP) system can run 3.2 faster on a 4-way SMP machine than on a single processor. The multithreaded encoder running on an SMP system is then used to understand the requirements of a chip multiprocessor (CMP) architecture, which is one possible architectural direction to better exploit TLP. In the framework of this study, we use a software approach to evaluate the dataflow between processors for the video encoder running on an SMP system. An estimation of the dataflow is done with L2 cache miss event counters using Intel® VTuneTM performance analyzer. The experimental measurements are compared to theoretical results.

Effect of thread shape on screw stress concentration by photoelastic measurements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dragoni, E.

1994-11-01

The screw stress concentration for six nut-bolt connections embodying three different thread profiles and two nut shapes is measured photoelastically. Buttress (nearly zero flank angle), trapezoidal (15-deg flank angle), and triangular (30-deg flank angle) thread forms are examined in combination with standard and lip-type nuts. The effect of the thread profile on the screw stress concentration appears to be dependent upon the kind of nut considered. If the fastening incorporates a standard nut, the buttress thread is stronger than the triangular one, which, in turn, behaves better than the trapezoidal contour. The improvement is roughly a 20% reduction in themore » stress concentration factor from the trapezoidal to the buttress thread. In the case of lip nut, conversely, this tendency is somewhat reversed, with the trapezoidal thread performing slightly (but not decidedly) better than the other two shapes. Finally, averaged over all three thread forms, the lip nut exhibits a stress concentration factor which is about 50% lower than that of the standard nut.« less

Quick connect fastener

NASA Technical Reports Server (NTRS)

Weddendorf, Bruce (Inventor)

1994-01-01

A quick connect fastener and method of use is presented wherein the quick connect fastener is suitable for replacing available bolts and screws, the quick connect fastener being capable of installation by simply pushing a threaded portion of the connector into a member receptacle hole, the inventive apparatus being comprised of an externally threaded fastener having a threaded portion slidably mounted upon a stud or bolt shaft, wherein the externally threaded fastener portion is expandable by a preloaded spring member. The fastener, upon contact with the member receptacle hole, has the capacity of presenting cylindrical threads of a reduced diameter for insertion purposes and once inserted into the receiving threads of the receptacle member hole, are expandable for engagement of the receptacle hole threads forming a quick connect of the fastener and the member to be fastened, the quick connect fastener can be further secured by rotation after insertion, even to the point of locking engagement, the quick connect fastener being disengagable only by reverse rotation of the mated thread engagement.

Form and function of cnidarian spirocysts. III. Ultrastructure of the thread and the function of spirocysts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mariscal, R.N.; McLean, R.B.; Hand, C.

1977-01-01

Unlike most nematocysts, undischarged spirocyst threads bear hollow tubules rather than spines. The undischarged tubules are interconnected in hexagonal arrays and appear to be arranged in bundles along the length of the thread. Although the wall of the thread is folded in length and width, the tubules are not. Upon discharge and contact with sea water, the tubules solubilize and adhere to various substrates and prey. Traction between such objects and the everting thread causes the tubules to spin out into a web or meshwork of fine microfibrillae. Lack of contact of the everting thread with objects results in themore » tubules forming small droplets of partially solubilized material, some of which appear to be arranged in a helical pattern around the thread. The web or meshwork formed by the solubilized tubules in contact with various substrates probably serves to increase significantly the surface area and adhesive properties of the everted spirocyst thread.« less

From Physics Model to Results: An Optimizing Framework for Cross-Architecture Code Generation

DOE PAGES

Blazewicz, Marek; Hinder, Ian; Koppelman, David M.; ...

2013-01-01

Starting from a high-level problem description in terms of partial differential equations using abstract tensor notation, the Chemora framework discretizes, optimizes, and generates complete high performance codes for a wide range of compute architectures. Chemora extends the capabilities of Cactus, facilitating the usage of large-scale CPU/GPU systems in an efficient manner for complex applications, without low-level code tuning. Chemora achieves parallelism through MPI and multi-threading, combining OpenMP and CUDA. Optimizations include high-level code transformations, efficient loop traversal strategies, dynamically selected data and instruction cache usage strategies, and JIT compilation of GPU code tailored to the problem characteristics. The discretization ismore » based on higher-order finite differences on multi-block domains. Chemora's capabilities are demonstrated by simulations of black hole collisions. This problem provides an acid test of the framework, as the Einstein equations contain hundreds of variables and thousands of terms.« less

Gregarious Data Re-structuring in a Many Core Architecture

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shrestha, Sunil; Manzano Franco, Joseph B.; Marquez, Andres

this paper, we have developed a new methodology that takes in consideration the access patterns from a single parallel actor (e.g. a thread), as well as, the access patterns of “grouped” parallel actors that share a resource (e.g. a distributed Level 3 cache). We start with a hierarchical tile code for our target machine and apply a series of transformations at the tile level to improve data residence in a given memory hierarchy level. The contribution of this paper includes (a) collaborative data restructuring for group reuse and (b) low overhead transformation technique to improve access pattern and bring closelymore » connected data elements together. Preliminary results in a many core architecture, Tilera TileGX, shows promising improvements over optimized OpenMP code (up to 31% increase in GFLOPS) and over our own previous work on fine grained runtimes (up to 16%) for selected kernels« less

Petrology and geochemistry of primitive lower oceanic crust from Pito Deep: Implications for the accretion of the lower crust at the Southern East Pacific Rise

USGS Publications Warehouse

Perk, N.W.; Coogan, L.A.; Karson, J.A.; Klein, E.M.; Hanna, H.D.

2007-01-01

A suite of samples collected from the uppermost part of the plutonic section of the oceanic crust formed at the southern East Pacific Rise and exposed at the Pito Deep has been examined. These rocks were sampled in situ by ROV and lie beneath a complete upper crustal section providing geological context. This is only the second area (after the Hess Deep) in which a substantial depth into the plutonic complex formed at the East Pacific Rise has been sampled in situ and reveals significant spatial heterogeneity in the plutonic complex. In contrast to the uppermost plutonic rocks at Hess Deep, the rocks studied here are generally primitive with olivine forsterite contents mainly between 85 and 88 and including many troctolites. The melt that the majority of the samples crystallized from was aggregated normal mid-ocean ridge basalt (MORB). Despite this high Mg# clinopyroxene is common despite model predictions that clinopyroxene should not reach the liquidus early during low-pressure crystallization of MORB. Stochastic modeling of melt crystallisation at various levels in the crust suggests that it is unlikely that a significant melt mass crystallized in the deeper crust (for example in sills) because this would lead to more evolved shallow level plutonic rocks. Similar to the upper plutonic section at Hess Deep, and in the Oman ophiolite, many samples show a steeply dipping, axis-parallel, magmatic fabric. This suggests that vertical magmatic flow is an important process in the upper part of the seismic low velocity zone beneath fast-spreading ridges. We suggest that both temporal and spatial (along-axis) variability in the magmatic and hydrothermal systems can explain the differences observed between the Hess Deep and Pito Deep plutonics. ?? Springer-Verlag 2007.

On Synchronization Primitive Systems.

DTIC Science & Technology

The report studies the question: what synchronization primitive should be used to handle inter-process communication. A formal model is presented...between these synchronization primitives. Although only four synchronization primitives are compared, the general methods can be used to compare other... synchronization primitives. Moreover, in the definitions of these synchronization primitives, conditional branches are explicitly allowed. In addition

Dust formation in a galaxy with primitive abundances.

PubMed

Sloan, G C; Matsuura, M; Zijlstra, A A; Lagadec, E; Groenewegen, M A T; Wood, P R; Szyszka, C; Bernard-Salas, J; van Loon, J Th

2009-01-16

Interstellar dust plays a crucial role in the evolution of galaxies. It governs the chemistry and physics of the interstellar medium. In the local universe, dust forms primarily in the ejecta from stars, but its composition and origin in galaxies at very early times remain controversial. We report observational evidence of dust forming around a carbon star in a nearby galaxy with a low abundance of heavy elements, 25 times lower than the solar abundance. The production of dust by a carbon star in a galaxy with such primitive abundances raises the possibility that carbon stars contributed carbonaceous dust in the early universe.

Thread bonds in molecules

NASA Astrophysics Data System (ADS)

Ivlev, B.

2017-07-01

Unusual chemical bonds are proposed. Each bond is characterized by the thread of a small radius, 10-11 cm, extended between two nuclei in a molecule. An analogue of a potential well, of the depth of MeV scale, is formed within the thread. This occurs due to the local reduction of zero point electromagnetic energy. This is similar to formation of the Casimir well. The electron-photon interaction only is not sufficient for formation of thread state. The mechanism of electron mass generation is involved in the close vicinity, 10-16 cm, of the thread. Thread bonds are stable and cannot be created or destructed in chemical or optical processes.

Flare particle acceleration in the interaction of twisted coronal flux ropes

NASA Astrophysics Data System (ADS)

Threlfall, J.; Hood, A. W.; Browning, P. K.

2018-03-01

Aim. The aim of this work is to investigate and characterise non-thermal particle behaviour in a three-dimensional (3D) magnetohydrodynamical (MHD) model of unstable multi-threaded flaring coronal loops. Methods: We have used a numerical scheme which solves the relativistic guiding centre approximation to study the motion of electrons and protons. The scheme uses snapshots from high resolution numerical MHD simulations of coronal loops containing two threads, where a single thread becomes unstable and (in one case) destabilises and merges with an additional thread. Results: The particle responses to the reconnection and fragmentation in MHD simulations of two loop threads are examined in detail. We illustrate the role played by uniform background resistivity and distinguish this from the role of anomalous resistivity using orbits in an MHD simulation where only one thread becomes unstable without destabilising further loop threads. We examine the (scalable) orbit energy gains and final positions recovered at different stages of a second MHD simulation wherein a secondary loop thread is destabilised by (and merges with) the first thread. We compare these results with other theoretical particle acceleration models in the context of observed energetic particle populations during solar flares.

Long-term effect of the insoluble thread-lifting technique.

PubMed

Fukaya, Mototsugu

2017-01-01

Although the thread-lifting technique for sagging faces has become more common and popular, medical literature evaluating its effects is scarce. Studies on its long-term prognosis are particularly uncommon. One hundred individuals who had previously undergone insoluble thread-lifting were retrospectively investigated. Photos in frontal and oblique views from the first and last visits were evaluated by six female individuals by guessing the patients' ages. The mean guessed age was defined as the apparent age, and the difference between the real and apparent ages was defined as the youth value. The difference between the youth values before and after the thread-lift was defined as the rejuvenation effect and analyzed in relation to the time since the operation, the number of threads used and the number of thread-lift operations performed. The rejuvenation effect decreased over the first year after the operation, but showed an increasing trend thereafter. The rejuvenation effect increased with the number of threads used and the number of thread-lift operations performed. The insoluble thread-lifting technique appears to be associated with both early and late effects. The rejuvenation effect appeared to decrease during the first year, but increased thereafter. A multicenter trial is necessary to confirm these findings.

The Ethylene Responsive Factor Required for Nodulation 1 (ERN1) Transcription Factor Is Required for Infection-Thread Formation in Lotus japonicus.

PubMed

Kawaharada, Yasuyuki; James, Euan K; Kelly, Simon; Sandal, Niels; Stougaard, Jens

2017-03-01

Several hundred genes are transcriptionally regulated during infection-thread formation and development of nitrogen-fixing root nodules. We have characterized a set of Lotus japonicus mutants impaired in root-nodule formation and found that the causative gene, Ern1, encodes a protein with a characteristic APETALA2/Ethylene Responsive Factor (AP2/ERF) transcription-factor domain. Phenotypic characterization of four ern1 alleles shows that infection pockets are formed but root-hair infection threads are absent. Formation of root-nodule primordia is delayed and no normal transcellular infection threads are found in the infected nodules. Corroborating the role of ERN1 (ERF Required for Nodulation1) in nodule organogenesis, spontaneous nodulation induced by an autoactive CCaMK and cytokinin-induced nodule primordia were not observed in ern1 mutants. Expression of Ern1 is induced in the susceptible zone by Nod factor treatment or rhizobial inoculation. At the cellular level, the pErn1:GUS reporter is highly expressed in root epidermal cells of the susceptible zone and in the cortical cells that form nodule primordia. The genetic regulation of this cellular expression pattern was further investigated in symbiotic mutants. Nod factor induction of Ern1 in epidermal cells was found to depend on Nfr1, Cyclops, and Nsp2 but was independent of Nin and Nf-ya1. These results suggest that ERN1 functions as a transcriptional regulator involved in the formation of infection threads and development of nodule primordia and may coordinate these two processes.

Thread Migration in the Presence of Pointers

NASA Technical Reports Server (NTRS)

Cronk, David; Haines, Matthew; Mehrotra, Piyush

1996-01-01

Dynamic migration of lightweight threads supports both data locality and load balancing. However, migrating threads that contain pointers referencing data in both the stack and heap remains an open problem. In this paper we describe a technique by which threads with pointers referencing both stack and non-shared heap data can be migrated such that the pointers remain valid after migration. As a result, threads containing pointers can now be migrated between processors in a homogeneous distributed memory environment.

Real-time inextensible surgical thread simulation.

PubMed

Xu, Lang; Liu, Qian

2018-03-27

This paper discusses a real-time simulation method of inextensible surgical thread based on the Cosserat rod theory using position-based dynamics (PBD). The method realizes stable twining and knotting of surgical thread while including inextensibility, bending, twisting and coupling effects. The Cosserat rod theory is used to model the nonlinear elastic behavior of surgical thread. The surgical thread model is solved with PBD to achieve a real-time, extremely stable simulation. Due to the one-dimensional linear structure of surgical thread, the direct solution of the distance constraint based on tridiagonal matrix algorithm is used to enhance stretching resistance in every constraint projection iteration. In addition, continuous collision detection and collision response guarantee a large time step and high performance. Furthermore, friction is integrated into the constraint projection process to stabilize the twining of multiple threads and complex contact situations. Through comparisons with existing methods, the surgical thread maintains constant length under large deformation after applying the direct distance constraint in our method. The twining and knotting of multiple threads correspond to stable solutions to contact and friction forces. A surgical suture scene is also modeled to demonstrate the practicality and simplicity of our method. Our method achieves stable and fast simulation of inextensible surgical thread. Benefiting from the unified particle framework, the rigid body, elastic rod, and soft body can be simultaneously simulated. The method is appropriate for applications in virtual surgery that require multiple dynamic bodies.

[Time and use of discussion forums in type 1 diabetes: contribution to patient education].

PubMed

Harry, Isabelle; Gagnayre, Rémi

2013-01-01

The purpose of this study was to elucidate the concept of temporality in discussions on forums used by individuals concerned by type 1 diabetes: adults and parents of children. The contents of messages were first converted into skills, and their temporality was then analysed, particularly in terms of the duration of active threads. Two types of temporality are involved in the use of forums: prescribed time governed by the therapeutic requirements related to a chronic disease and the decisions to be taken, and open-ended social time available on the Internet and the resulting reflexive processes. Our results show that topics relating to self-care and adaptation skills are often discussed and new threads on the topic are frequently introduced. Considerable diversity in the activity level associated with the various threads was observed, as most threads were only active for short periods. Following this study, our research perspectives concern: (i) the ways in which patients and their families reconcile the temporality dictated by a chronic disease (prescribed time) with the open-ended social time available on the Internet; and (ii) the ways in which this temporality is characteristic of patient learning processes via discussion forums. Future research will focus on the concept of rythmo-apprenance (rhythmic learning) in therapeutic patient education.

Parallel approach for bioinspired algorithms

NASA Astrophysics Data System (ADS)

Zaporozhets, Dmitry; Zaruba, Daria; Kulieva, Nina

2018-05-01

In the paper, a probabilistic parallel approach based on the population heuristic, such as a genetic algorithm, is suggested. The authors proposed using a multithreading approach at the micro level at which new alternative solutions are generated. On each iteration, several threads that independently used the same population to generate new solutions can be started. After the work of all threads, a selection operator combines obtained results in the new population. To confirm the effectiveness of the suggested approach, the authors have developed software on the basis of which experimental computations can be carried out. The authors have considered a classic optimization problem – finding a Hamiltonian cycle in a graph. Experiments show that due to the parallel approach at the micro level, increment of running speed can be obtained on graphs with 250 and more vertices.

Short communication: first report of nematodes parasitizing the four-eyed-fish, Anableps anableps (Pisces, Cyprinodontiformes).

PubMed

Ribeiro, Juliana Souza; de Oliveira, Francisco Carlos Rodrigues; Ederli, Nicole Brand

2017-08-01

The genus Anableps is composed of species Anableps anableps, Anableps dowi, and Anableps microlepis. These fishes are tropical and usually live on the surface of brackish water, being popularly known as four-eyed-fishes due to the presence of prominent eyes and a pupil split horizontally. A. anableps and A. microlepis are considered as sister species that live in sympatry in South America. A. dowi, however, is restricted to the Pacific Ocean (Central America) and is considered the most primitive species of this genus. The aims of this study were to investigate the presence of endoparasites in A. anableps from the Parnaíba's Delta and characterize them morphologically. During the necropsy, larvae of Contracaecum sp. in the third larval stage (L3) were collected from the pancreas of A. anableps, but no endoparasites were observed in other organs. The worms had a cuticular tooth and excretory pore located at the anterior end, a thread like body, whitish color, and without distinction of sex. The length of the ventricular appendix of the larvae was much greater than in other studies. This is the first report of endoparasitism in A. anableps and the first report of nematodes in four-eyed-fishes.

Threaded biliary inside stents are a safe and effective therapeutic option in cases of malignant hilar obstruction

PubMed Central

2013-01-01

Background Although endoscopic biliary stents have been accepted as part of palliative therapy for cases of malignant hilar obstruction, the optimal endoscopic management regime remains controversial. In this study, we evaluated the safety and efficacy of placing a threaded stent above the sphincter of Oddi (threaded inside plastic stents, threaded PS) and compared the results with those of other stent types. Methods Patients with malignant hilar obstruction, including those requiring biliary drainage for stent occlusion, were selected. Patients received either one of the following endoscopic indwelling stents: threaded PS, conventional plastic stents (conventional PS), or metallic stents (MS). Duration of stent patency and the incident of complication were compared in these patients. Results Forty-two patients underwent placement of endoscopic indwelling stents (threaded PS = 12, conventional PS = 17, MS = 13). The median duration of threaded PS patency was significantly longer than that of conventional PS patency (142 vs. 32 days; P = 0.04, logrank test). The median duration of threaded PS and MS patency was not significantly different (142 vs. 150 days, P = 0.83). Stent migration did not occur in any group. Among patients who underwent threaded PS placement as a salvage therapy after MS obstruction due to tumor ingrowth, the median duration of MS patency was significantly shorter than that of threaded PS patency (123 vs. 240 days). Conclusions Threaded PS are safe and effective in cases of malignant hilar obstruction; moreover, it is a suitable therapeutic option not only for initial drainage but also for salvage therapy. PMID:23410217

Parallel Implementation of 3-D Iterative Reconstruction With Intra-Thread Update for the jPET-D4

NASA Astrophysics Data System (ADS)

Lam, Chih Fung; Yamaya, Taiga; Obi, Takashi; Yoshida, Eiji; Inadama, Naoko; Shibuya, Kengo; Nishikido, Fumihiko; Murayama, Hideo

2009-02-01

One way to speed-up iterative image reconstruction is by parallel computing with a computer cluster. However, as the number of computing threads increases, parallel efficiency decreases due to network transfer delay. In this paper, we proposed a method to reduce data transfer between computing threads by introducing an intra-thread update. The update factor is collected from each slave thread and a global image is updated as usual in the first K sub-iteration. In the rest of the sub-iterations, the global image is only updated at an interval which is controlled by a parameter L. In between that interval, the intra-thread update is carried out whereby an image update is performed in each slave thread locally. We investigated combinations of K and L parameters based on parallel implementation of RAMLA for the jPET-D4 scanner. Our evaluation used four workstations with a total of 16 slave threads. Each slave thread calculated a different set of LORs which are divided according to ring difference numbers. We assessed image quality of the proposed method with a hotspot simulation phantom. The figure of merit was the full-width-half-maximum of hotspots and the background normalized standard deviation. At an optimum K and L setting, we did not find significant change in the output images. We also applied the proposed method to a Hoffman phantom experiment and found the difference due to intra-thread update was negligible. With the intra-thread update, computation time could be reduced by about 23%.

78 FR 12718 - Certain Steel Threaded Rod From the People's Republic of China: Affirmative Final Determination...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-25

... DEPARTMENT OF COMMERCE International Trade Administration [A-570-932] Certain Steel Threaded Rod... Preliminary Determination of the circumvention inquiry concerning the antidumping duty order on certain steel threaded rod (``steel threaded rod'') from the People's Republic of China (``PRC'').\\1\\ The period of...

Remote direct memory access over datagrams

DOEpatents

Grant, Ryan Eric; Rashti, Mohammad Javad; Balaji, Pavan; Afsahi, Ahmad

2014-12-02

A communication stack for providing remote direct memory access (RDMA) over a datagram network is disclosed. The communication stack has a user level interface configured to accept datagram related input and communicate with an RDMA enabled network interface card (NIC) via an NIC driver. The communication stack also has an RDMA protocol layer configured to supply one or more data transfer primitives for the datagram related input of the user level. The communication stack further has a direct data placement (DDP) layer configured to transfer the datagram related input from a user storage to a transport layer based on the one or more data transfer primitives by way of a lower layer protocol (LLP) over the datagram network.

Influence of multi-cycle loading on the structure and mechanics of marine mussel plaques.

PubMed

Wilhelm, Menaka H; Filippidi, Emmanouela; Waite, J Herbert; Valentine, Megan T

2017-10-18

The proteinaceous byssal plaque-thread structures created by marine mussels exhibit extraordinary load-bearing capability. Although the nanoscopic protein interactions that support interfacial adhesion are increasingly understood, major mechanistic questions about how mussel plaques maintain toughness on supramolecular scales remain unanswered. This study explores the mechanical properties of whole mussel plaques subjected to repetitive loading cycles, with varied recovery times. Mechanical measurements were complemented with scanning electron microscopy to investigate strain-induced structural changes after yield. Multicyclic loading of plaques decreases their low-strain stiffness and introduces irreversible, strain-dependent plastic damage within the plaque microstructure. However, strain history does not compromise critical strength or maximum extension compared with plaques monotonically loaded to failure. These results suggest that a multiplicity of force transfer mechanisms between the thread and plaque-substrate interface allow the plaque-thread structure to accommodate a wide range of extensions as it continues to bear load. This improved understanding of the mussel system at micron-to-millimeter lengthscales offers strategies for including similar fail-safe mechanisms in the design of soft, tough and resilient synthetic structures.

Issues Related to Cleaning Complex Geometry Surfaces with ODC-Free Solvents

NASA Technical Reports Server (NTRS)

Bradford, Blake F.; Wurth, Laura A.; Nayate, Pramod D.; McCool, Alex (Technical Monitor)

2001-01-01

Implementing ozone depleting chemicals (ODC)-free solvents into full-scale reusable solid rocket motor cleaning operations has presented problems due to the low vapor pressures of the solvents. Because of slow evaporation, solvent retention is a problem on porous substrates or on surfaces with irregular geometry, such as threaded boltholes, leak check ports, and nozzle backfill joints. The new solvents are being evaluated to replace 1,1,1-trichloroethane, which readily evaporates from these surfaces. Selection of the solvents to be evaluated on full-scale hardware was made based on results of subscale tests performed with flat surface coupons, which did not manifest the problem. Test efforts have been undertaken to address concerns with the slow-evaporating solvents. These concerns include effects on materials due to long-term exposure to solvent, potential migration from bolthole threads to seal surfaces, and effects on bolt loading due to solvent retention in threads. Tests performed to date have verified that retained solvent does not affect materials or hardware performance. Process modifications have also been developed to assist drying, and these can be implemented if additional drying becomes necessary.

Rod Has High Tensile Strength And Low Thermal Expansion

NASA Technical Reports Server (NTRS)

Smith, D. E.; Everton, R. L.; Howe, E.; O'Malley, M.

1996-01-01

Thoriated tungsten extension rod fabricated to replace stainless-steel extension rod attached to linear variable-differential transformer in gap-measuring gauge. Threads formed on end of rod by machining with special fixtures and carefully chosen combination of speeds and feeds.

Nebo: An efficient, parallel, and portable domain-specific language for numerically solving partial differential equations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Earl, Christopher; Might, Matthew; Bagusetty, Abhishek

This study presents Nebo, a declarative domain-specific language embedded in C++ for discretizing partial differential equations for transport phenomena on multiple architectures. Application programmers use Nebo to write code that appears sequential but can be run in parallel, without editing the code. Currently Nebo supports single-thread execution, multi-thread execution, and many-core (GPU-based) execution. With single-thread execution, Nebo performs on par with code written by domain experts. With multi-thread execution, Nebo can linearly scale (with roughly 90% efficiency) up to 12 cores, compared to its single-thread execution. Moreover, Nebo’s many-core execution can be over 140x faster than its single-thread execution.

Three-dimensional imaging of threading dislocations in GaN crystals using two-photon excitation photoluminescence

NASA Astrophysics Data System (ADS)

Tanikawa, Tomoyuki; Ohnishi, Kazuki; Kanoh, Masaya; Mukai, Takashi; Matsuoka, Takashi

2018-03-01

The three-dimensional imaging of threading dislocations in GaN films was demonstrated using two-photon excitation photoluminescence. The threading dislocations were shown as dark lines. The spatial resolutions near the surface were about 0.32 and 3.2 µm for the in-plane and depth directions, respectively. The threading dislocations with a density less than 108 cm-2 were resolved, although the aberration induced by the refractive index mismatch was observed. The decrease in threading dislocation density was clearly observed by increasing the GaN film thickness. This can be considered a novel method for characterizing threading dislocations in GaN films without any destructive preparations.

Nebo: An efficient, parallel, and portable domain-specific language for numerically solving partial differential equations

DOE PAGES

Earl, Christopher; Might, Matthew; Bagusetty, Abhishek; ...

2016-01-26

This study presents Nebo, a declarative domain-specific language embedded in C++ for discretizing partial differential equations for transport phenomena on multiple architectures. Application programmers use Nebo to write code that appears sequential but can be run in parallel, without editing the code. Currently Nebo supports single-thread execution, multi-thread execution, and many-core (GPU-based) execution. With single-thread execution, Nebo performs on par with code written by domain experts. With multi-thread execution, Nebo can linearly scale (with roughly 90% efficiency) up to 12 cores, compared to its single-thread execution. Moreover, Nebo’s many-core execution can be over 140x faster than its single-thread execution.

Message passing with queues and channels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dozsa, Gabor J; Heidelberger, Philip; Kumar, Sameer

In an embodiment, a reception thread receives a source node identifier, a type, and a data pointer from an application and, in response, creates a receive request. If the source node identifier specifies a source node, the reception thread adds the receive request to a fast-post queue. If a message received from a network does not match a receive request on a posted queue, a polling thread adds a receive request that represents the message to an unexpected queue. If the fast-post queue contains the receive request, the polling thread removes the receive request from the fast-post queue. If themore » receive request that was removed from the fast-post queue does not match the receive request on the unexpected queue, the polling thread adds the receive request that was removed from the fast-post queue to the posted queue. The reception thread and the polling thread execute asynchronously from each other.« less

A software bus for thread objects

NASA Technical Reports Server (NTRS)

Callahan, John R.; Li, Dehuai

1995-01-01

The authors have implemented a software bus for lightweight threads in an object-oriented programming environment that allows for rapid reconfiguration and reuse of thread objects in discrete-event simulation experiments. While previous research in object-oriented, parallel programming environments has focused on direct communication between threads, our lightweight software bus, called the MiniBus, provides a means to isolate threads from their contexts of execution by restricting communications between threads to message-passing via their local ports only. The software bus maintains a topology of connections between these ports. It routes, queues, and delivers messages according to this topology. This approach allows for rapid reconfiguration and reuse of thread objects in other systems without making changes to the specifications or source code. A layered approach that provides the needed transparency to developers is presented. Examples of using the MiniBus are given, and the value of bus architectures in building and conducting simulations of discrete-event systems is discussed.

Embroidered Electromyography: A Systematic Design Guide.

PubMed

Shafti, Ali; Ribas Manero, Roger B; Borg, Amanda M; Althoefer, Kaspar; Howard, Matthew J

2017-09-01

Muscle activity monitoring or electromyography (EMG) is a useful tool. However, EMG is typically invasive, expensive and difficult to use for untrained users. A possible solution is textile-based surface EMG (sEMG) integrated into clothing as a wearable device. This is, however, challenging due to 1) uncertainties in the electrical properties of conductive threads used for electrodes, 2) imprecise fabrication technologies (e.g., embroidery, sewing), and 3) lack of standardization in design variable selection. This paper, for the first time, provides a design guide for such sensors by performing a thorough examination of the effect of design variables on sEMG signal quality. Results show that imprecisions in digital embroidery lead to a trade-off between low electrode impedance and high manufacturing consistency. An optimum set of variables for this trade-off is identified and tested with sEMG during a variable force isometric grip exercise with n = 12 participants, compared with conventional gel-based electrodes. Results show that thread-based electrodes provide a similar level of sensitivity to force variation as gel-based electrodes with about 90% correlation to expected linear behavior. As proof of concept, jogging leggings with integrated embroidered sEMG are made and successfully tested for detection of muscle fatigue while running on different surfaces.

Presentation of a large amount of moving objects in a virtual environment

NASA Astrophysics Data System (ADS)

Ye, Huanzhuo; Gong, Jianya; Ye, Jing

2004-05-01

It needs a lot of consideration to manage the presentation of a large amount of moving objects in virtual environment. Motion state model (MSM) is used to represent the motion of objects and 2n tree is used to index the motion data stored in database or files. To minimize the necessary memory occupation for static models, cache with LRU or FIFO refreshing is introduced. DCT and wavelet work well with different playback speeds of motion presentation because they can filter low frequencies from motion data and adjust the filter according to playback speed. Since large amount of data are continuously retrieved, calculated, used for displaying, and then discarded, multithreading technology is naturally employed though single thread with carefully arranged data retrieval also works well when the number of objects is not very big. With multithreading, the level of concurrence should be placed at data retrieval, where waiting may occur, rather than at calculating or displaying, and synchronization should be carefully arranged to make sure that different threads can collaborate well. Collision detection is not needed when playing with history data and sampled current data; however, it is necessary for spatial state prediction. When the current state is presented, either predicting-adjusting method or late updating method could be used according to the users' preference.

49 CFR 178.42 - Specification 3E seamless steel cylinders.

Code of Federal Regulations, 2012 CFR

2012-10-01

... (valves, fuse plugs, etc.) for those openings. Threads conforming to the following are required on openings. (1) Threads must be clean cut, even, without checks, and to gauge. (2) Taper threads, when used, must be of length not less than as specified for American Standard taper pipe threads. (3) Straight...

49 CFR 178.42 - Specification 3E seamless steel cylinders.

Code of Federal Regulations, 2013 CFR

2013-10-01

... (valves, fuse plugs, etc.) for those openings. Threads conforming to the following are required on openings. (1) Threads must be clean cut, even, without checks, and to gauge. (2) Taper threads, when used, must be of length not less than as specified for American Standard taper pipe threads. (3) Straight...

Neuropil threads occur in dendrites of tangle-bearing nerve cells.

PubMed

Braak, H; Braak, E

1988-01-01

Transparent Golgi preparations counterstained for Alzheimer's neurofibrillary changes rendered possible the demonstration of neuropil threads in defined cellular processes. Only dendrites of tangle-bearing cortical nerve cells were found to contain neuropil threads. Processes of glial cells as well as axons present in the material were devoid of neuropil threads.

49 CFR 178.42 - Specification 3E seamless steel cylinders.

Code of Federal Regulations, 2010 CFR

2010-10-01

... (valves, fuse plugs, etc.) for those openings. Threads conforming to the following are required on openings. (1) Threads must be clean cut, even, without checks, and to gauge. (2) Taper threads, when used, must be of length not less than as specified for American Standard taper pipe threads. (3) Straight...

Threaded Cognition: An Integrated Theory of Concurrent Multitasking

ERIC Educational Resources Information Center

Salvucci, Dario D.; Taatgen, Niels A.

2008-01-01

The authors propose the idea of threaded cognition, an integrated theory of concurrent multitasking--that is, performing 2 or more tasks at once. Threaded cognition posits that streams of thought can be represented as threads of processing coordinated by a serial procedural resource and executed across other available resources (e.g., perceptual…

49 CFR 178.42 - Specification 3E seamless steel cylinders.

Code of Federal Regulations, 2011 CFR

2011-10-01

... (valves, fuse plugs, etc.) for those openings. Threads conforming to the following are required on openings. (1) Threads must be clean cut, even, without checks, and to gauge. (2) Taper threads, when used, must be of length not less than as specified for American Standard taper pipe threads. (3) Straight...

49 CFR 178.42 - Specification 3E seamless steel cylinders.

Code of Federal Regulations, 2014 CFR

2014-10-01

... (valves, fuse plugs, etc.) for those openings. Threads conforming to the following are required on openings. (1) Threads must be clean cut, even, without checks, and to gauge. (2) Taper threads, when used, must be of length not less than as specified for American Standard taper pipe threads. (3) Straight...

A Primer on the Effective Use of Threaded Discussion Forums.

ERIC Educational Resources Information Center

Kirk, James J.; Orr, Robert L.

Threaded discussion forums are asynchronous, World Wide Web-based discussions occurring under a number of different topics called threads. By allowing students to post, read, and respond to messages independently of time or place, threaded discussion forums give students an opportunity for deeper reflection and more thoughtful replies than chat…

46 CFR 164.023-7 - Performance; non-standard thread.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 6 2010-10-01 2010-10-01 false Performance; non-standard thread. 164.023-7 Section 164... Performance; non-standard thread. (a) Use Codes 1, 2, 3, 4BC, 4RB, 5 (any). Each non-standard thread which...) testing machine. (2) Single strand breaking strength (after weathering). After exposure in a sunshine...

46 CFR 164.023-7 - Performance; non-standard thread.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 6 2011-10-01 2011-10-01 false Performance; non-standard thread. 164.023-7 Section 164... Performance; non-standard thread. (a) Use Codes 1, 2, 3, 4BC, 4RB, 5 (any). Each non-standard thread which...) testing machine. (2) Single strand breaking strength (after weathering). After exposure in a sunshine...

Threaded average temperature thermocouple

NASA Technical Reports Server (NTRS)

Ward, Stanley W. (Inventor)

1990-01-01

A threaded average temperature thermocouple 11 is provided to measure the average temperature of a test situs of a test material 30. A ceramic insulator rod 15 with two parallel holes 17 and 18 through the length thereof is securely fitted in a cylinder 16, which is bored along the longitudinal axis of symmetry of threaded bolt 12. Threaded bolt 12 is composed of material having thermal properties similar to those of test material 30. Leads of a thermocouple wire 20 leading from a remotely situated temperature sensing device 35 are each fed through one of the holes 17 or 18, secured at head end 13 of ceramic insulator rod 15, and exit at tip end 14. Each lead of thermocouple wire 20 is bent into and secured in an opposite radial groove 25 in tip end 14 of threaded bolt 12. Resulting threaded average temperature thermocouple 11 is ready to be inserted into cylindrical receptacle 32. The tip end 14 of the threaded average temperature thermocouple 11 is in intimate contact with receptacle 32. A jam nut 36 secures the threaded average temperature thermocouple 11 to test material 30.

Hyperunstable matrix proteins in the byssus of Mytilus galloprovincialis.

PubMed

Sagert, Jason; Waite, J Herbert

2009-07-01

The marine mussel Mytilus galloprovincialis is tethered to rocks in the intertidal zone by a holdfast known as the byssus. Functioning as a shock absorber, the byssus is composed of threads, the primary molecular components of which are collagen-containing proteins (preCOLs) that largely dictate the higher order self-assembly and mechanical properties of byssal threads. The threads contain additional matrix components that separate and perhaps lubricate the collagenous microfibrils during deformation in tension. In this study, the thread matrix proteins (TMPs), a glycine-, tyrosine- and asparagine-rich protein family, were shown to possess unique repeated sequence motifs, significant transcriptional heterogeneity and were distributed throughout the byssal thread. Deamidation was shown to occur at a significant rate in a recombinant TMP and in the byssal thread as a function of time. Furthermore, charge heterogeneity presumably due to deamidation was observed in TMPs extracted from threads. The TMPs were localized to the preCOL-containing secretory granules in the collagen gland of the foot and are assumed to provide a viscoelastic matrix around the collagenous fibers in byssal threads.

QCAPUF: QCA-based physically unclonable function as a hardware security primitive

NASA Astrophysics Data System (ADS)

Abutaleb, M. M.

2018-04-01

Physically unclonable functions (PUFs) are increasingly used as innovative security primitives to provide the hardware authentication and identification as well as the secret key generation based on unique and random variations in identically fabricated devices. Security and low power have appeared to become two crucial necessities to modern designs. As an emerging nanoelectronic technology, a quantum-dot cellular automata (QCA) can achieve ultra-low power consumption as well as an extremely small area for implementing digital designs. However, there are various classes of permanent defects that can happen during the manufacture of QCA devices. The recent extensive research has been focused on how to eliminate errors in QCA structures resulting from fabrication variances. By a completely different vision, to turn this disadvantage into an advantage, this paper presents a novel QCA-based PUF (QCAPUF) architecture to exploit the unique physical characteristics of fabricated QCA cells in order to produce different hardware fingerprint instances. This architecture is composed of proposed logic and interconnect blocks that have critical vulnerabilities and perform unexpected logical operations. The behaviour of QCAPUF is thoroughly analysed through physical relations and simulations. Results confirm that the proposed QCAPUF has state of the art PUF characteristics in the QCA technology. This paper will serve as a basis for further research into QCA-based hardware security primitives and applications.

GaAsP/InGaP HBTs grown epitaxially on Si substrates: Effect of dislocation density on DC current gain

NASA Astrophysics Data System (ADS)

Heidelberger, Christopher; Fitzgerald, Eugene A.

2018-04-01

Heterojunction bipolar transistors (HBTs) with GaAs0.825P0.175 bases and collectors and In0.40Ga0.60P emitters were integrated monolithically onto Si substrates. The HBT structures were grown epitaxially on Si via metalorganic chemical vapor deposition, using SiGe compositionally graded buffers to accommodate the lattice mismatch while maintaining threading dislocation density at an acceptable level (˜3 × 106 cm-2). GaAs0.825P0.175 is used as an active material instead of GaAs because of its higher bandgap (increased breakdown voltage) and closer lattice constant to Si. Misfit dislocation density in the active device layers, measured by electron-beam-induced current, was reduced by making iterative changes to the epitaxial structure. This optimized process culminated in a GaAs0.825P0.175/In0.40Ga0.60P HBT grown on Si with a DC current gain of 156. By considering the various GaAsP/InGaP HBTs grown on Si substrates alongside several control devices grown on GaAs substrates, a wide range of threading dislocation densities and misfit dislocation densities in the active layers could be correlated with HBT current gain. The effect of threading dislocations on current gain was moderated by the reduction in minority carrier lifetime in the base region, in agreement with existing models for GaAs light-emitting diodes and photovoltaic cells. Current gain was shown to be extremely sensitive to misfit dislocations in the active layers of the HBT—much more sensitive than to threading dislocations. We develop a model for this relationship where increased base current is mediated by Fermi level pinning near misfit dislocations.

Differential regulation of the Epr3 receptor coordinates membrane-restricted rhizobial colonization of root nodule primordia

PubMed Central

Kawaharada, Yasuyuki; Nielsen, Mette W.; Kelly, Simon; James, Euan K.; Andersen, Kasper R.; Rasmussen, Sheena R.; Füchtbauer, Winnie; Madsen, Lene H.; Heckmann, Anne B.; Radutoiu, Simona; Stougaard, Jens

2017-01-01

In Lotus japonicus, a LysM receptor kinase, EPR3, distinguishes compatible and incompatible rhizobial exopolysaccharides at the epidermis. However, the role of this recognition system in bacterial colonization of the root interior is unknown. Here we show that EPR3 advances the intracellular infection mechanism that mediates infection thread invasion of the root cortex and nodule primordia. At the cellular level, Epr3 expression delineates progression of infection threads into nodule primordia and cortical infection thread formation is impaired in epr3 mutants. Genetic dissection of this developmental coordination showed that Epr3 is integrated into the symbiosis signal transduction pathways. Further analysis showed differential expression of Epr3 in the epidermis and cortical primordia and identified key transcription factors controlling this tissue specificity. These results suggest that exopolysaccharide recognition is reiterated during the progressing infection and that EPR3 perception of compatible exopolysaccharide promotes an intracellular cortical infection mechanism maintaining bacteria enclosed in plant membranes. PMID:28230048

Melting of the primitive martian mantle at 0.5-2.2 GPa and the origin of basalts and alkaline rocks on Mars

NASA Astrophysics Data System (ADS)

Collinet, Max; Médard, Etienne; Charlier, Bernard; Vander Auwera, Jacqueline; Grove, Timothy L.

2015-10-01

We have performed piston-cylinder experiments on a primitive martian mantle composition between 0.5 and 2.2 GPa and 1160 to 1550 °C. The composition of melts and residual minerals constrain the possible melting processes on Mars at 50 to 200 km depth under nominally anhydrous conditions. Silicate melts produced by low degrees of melting (<10 wt.%) were analyzed in layers of vitreous carbon spheres or in micro-cracks inside the graphite capsule. The total range of melt fractions investigated extends from 5 to 50 wt.%, and the liquids produced display variable SiO2 (43.7-59.0 wt.%), MgO (5.3-18.6 wt.%) and Na2O + K2O (1.0-6.5 wt.%) contents. We provide a new equation to estimate the solidus temperature of the martian mantle: T (°C) = 1033 + 168.1 P (GPa) - 14.22P2 (GPa), which places the solidus 50 °C below that of fertile terrestrial peridotites. Low- and high-degree melts are compared to martian alkaline rocks and basalts, respectively. We suggest that the parental melt of Adirondack-class basalts was produced by ∼25 wt.% melting of the primitive martian mantle at 1.5 GPa (∼135 km) and ∼1400 °C. Despite its brecciated nature, NWA 7034/7533 might be composed of material that initially crystallized from a primary melt produced by ∼10-30 wt.% melting at the same pressure. Other igneous rocks from Mars require mantle reservoirs with different CaO/Al2O3 and FeO/MgO ratios or the action of fractional crystallization. Alkaline rocks can be derived from mantle sources with alkali contents (∼0.5 wt.%) similar to the primitive mantle.

Sandboxes for Model-Based Inquiry

NASA Astrophysics Data System (ADS)

Brady, Corey; Holbert, Nathan; Soylu, Firat; Novak, Michael; Wilensky, Uri

2015-04-01

In this article, we introduce a class of constructionist learning environments that we call Emergent Systems Sandboxes ( ESSs), which have served as a centerpiece of our recent work in developing curriculum to support scalable model-based learning in classroom settings. ESSs are a carefully specified form of virtual construction environment that support students in creating, exploring, and sharing computational models of dynamic systems that exhibit emergent phenomena. They provide learners with "entity"-level construction primitives that reflect an underlying scientific model. These primitives can be directly "painted" into a sandbox space, where they can then be combined, arranged, and manipulated to construct complex systems and explore the emergent properties of those systems. We argue that ESSs offer a means of addressing some of the key barriers to adopting rich, constructionist model-based inquiry approaches in science classrooms at scale. Situating the ESS in a large-scale science modeling curriculum we are implementing across the USA, we describe how the unique "entity-level" primitive design of an ESS facilitates knowledge system refinement at both an individual and social level, we describe how it supports flexible modeling practices by providing both continuous and discrete modes of executability, and we illustrate how it offers students a variety of opportunities for validating their qualitative understandings of emergent systems as they develop.

DOE Office of Scientific and Technical Information (OSTI.GOV)

King, M. P.; Kaplar, R. J.; Dickerson, J. R.

Electrical performance and characterization of deep levels in vertical GaN P-i-N diodes grown on low threading dislocation density (~10 4 –10 6 cm –2) bulk GaN substrates are investigated. The lightly doped n drift region of these devices is observed to be highly compensated by several prominent deep levels detected using deep level optical spectroscopy at E c-2.13, 2.92, and 3.2 eV. A combination of steady-state photocapacitance and lighted capacitance-voltage profiling indicates the concentrations of these deep levels to be N t = 3 × 10 12, 2 × 10 15, and 5 × 10 14 cm –3, respectively. Themore » E c-2.92 eV level is observed to be the primary compensating defect in as-grown n-type metal-organic chemical vapor deposition GaN, indicating this level acts as a limiting factor for achieving controllably low doping. The device blocking voltage should increase if compensating defects reduce the free carrier concentration of the n drift region. Understanding the incorporation of as-grown and native defects in thick n-GaN is essential for enabling large V BD in the next-generation wide-bandgap power semiconductor devices. Furthermore, controlling the as-grown defects induced by epitaxial growth conditions is critical to achieve blocking voltage capability above 5 kV.« less

Self-cleaning threaded rod spinneret for high-efficiency needleless electrospinning

NASA Astrophysics Data System (ADS)

Zheng, Gaofeng; Jiang, Jiaxin; Wang, Xiang; Li, Wenwang; Zhong, Weizheng; Guo, Shumin

2018-07-01

High-efficiency production of nanofibers is the key to the application of electrospinning technology. This work focuses on multi-jet electrospinning, in which a threaded rod electrode is utilized as the needless spinneret to achieve high-efficiency production of nanofibers. A slipper block, which fits into and moves through the threaded rod, is designed to transfer polymer solution evenly to the surface of the rod spinneret. The relative motion between the slipper block and the threaded rod electrode promotes the instable fluctuation of the solution surface, thus the rotation of threaded rod electrode decreases the critical voltage for the initial multi-jet ejection and the diameter of nanofibers. The residual solution on the surface of threaded rod is cleaned up by the moving slipper block, showing a great self-cleaning ability, which ensures the stable multi-jet ejection and increases the productivity of nanofibers. Each thread of the threaded rod electrode serves as an independent spinneret, which enhances the electric field strength and constrains the position of the Taylor cone, resulting in high productivity of uniform nanofibers. The diameter of nanofibers decreases with the increase of threaded rod rotation speed, and the productivity increases with the solution flow rate. The rotation of electrode provides an excess force for the ejection of charged jets, which also contributes to the high-efficiency production of nanofibers. The maximum productivity of nanofibers from the threaded rod spinneret is 5-6 g/h, about 250-300 times as high as that from the single-needle spinneret. The self-cleaning threaded rod spinneret is an effective way to realize continuous multi-jet electrospinning, which promotes industrial applications of uniform nanofibrous membrane.

Petrogenesis of the Late Triassic diorites in the Hoh Xil area, northern Tibet: Insights into the origin of the high-Mg# andesitic signature of continental crust

NASA Astrophysics Data System (ADS)

Wang, Jun; Gou, Guo-Ning; Wang, Qiang; Zhang, Chunfu; Dan, Wei; Wyman, Derek A.; Zhang, Xiu-Zheng

2018-02-01

An integrated petrologic, geochronologic, major and trace element geochemical, and Sr-Nd-Hf isotopic study of Late Triassic ( 215 Ma) diorites from the Hoh Xil area, northern Tibet, provides new constraints on the genesis of intermediate magmas and insights into the origin of the high-Mg# andesitic signature of continental crust. These dioritic rocks are characterized by high MgO contents (3.3-5.0 wt%) and Mg# values (50-57) comparable to the estimates for the bulk continental crust at the same level of SiO2 contents (61.1-64.5 wt%). They also display continental crust-like trace element distribution patterns and uniformly enriched isotope compositions ([87Sr/86Sr]i = 0.7081 to 0.7094, ɛNd[t] = - 8.0 to - 6.9, and ɛHf[t]zircon = - 10.1 to - 5.0). Combining our results with published data from crystallization experiments, we propose that they were probably produced by fractional crystallization from a primitive andesite parent, rather than a primitive basalt parent. This parental magma may be geochemically similar to the roughly contemporaneous primitive andesites in the adjacent Malanshan area of northern Tibet. Our compilation of modern arc lavas shows that progressive fractional crystallization of primitive andesites is also required to reproduce the Mg# versus SiO2 array for natural arc magmas, in addition to differentiation of mantle-derived primitive basaltic magmas and/or mixing of basaltic with felsic magmas. Therefore, we emphasize that fractional crystallization of primitive andesitic magmas is potentially a frequent occurrence in arc crust and hence may play an important role in producing the high-Mg# signature of intermediate magmas comprising the continental crust.

Microfluidic assay of the deformability of primitive erythroblasts.

PubMed

Zhou, Sitong; Huang, Yu-Shan; Kingsley, Paul D; Cyr, Kathryn H; Palis, James; Wan, Jiandi

2017-09-01

Primitive erythroblasts (precursors of red blood cells) enter vascular circulation during the embryonic period and mature while circulating. As a result, primitive erythroblasts constantly experience significant hemodynamic shear stress. Shear-induced deformation of primitive erythroblasts however, is poorly studied. In this work, we examined the deformability of primitive erythroblasts at physiologically relevant flow conditions in microfluidic channels and identified the regulatory roles of the maturation stage of primitive erythroblasts and cytoskeletal protein 4.1 R in shear-induced cell deformation. The results showed that the maturation stage affected the deformability of primitive erythroblasts significantly and that primitive erythroblasts at later maturational stages exhibited a better deformability due to a matured cytoskeletal structure in the cell membrane.

Programming distributed memory architectures using Kali

NASA Technical Reports Server (NTRS)

Mehrotra, Piyush; Vanrosendale, John

1990-01-01

Programming nonshared memory systems is more difficult than programming shared memory systems, in part because of the relatively low level of current programming environments for such machines. A new programming environment is presented, Kali, which provides a global name space and allows direct access to remote data values. In order to retain efficiency, Kali provides a system on annotations, allowing the user to control those aspects of the program critical to performance, such as data distribution and load balancing. The primitives and constructs provided by the language is described, and some of the issues raised in translating a Kali program for execution on distributed memory systems are also discussed.

Etude comparative sur la propagation de l'endommagement apres impact des composites carbone/epoxy renforces par piquage au fil Kevlar et titane-nickel

NASA Astrophysics Data System (ADS)

Vachon, Pierre-Luc

Composite laminates have strong in-plane mechanical properties, but they are generally weaker through their thickness. This specificity makes the laminates prone to delamination, particularly under low-velocity impact loads. Consequently numerous research efforts have been dedicated to developing interlaminar reinforcing methods, such as transverse stitching. The present project proposes the use of the stitching technique combined with a special stitching thread made of superelastic TiNi alloy. This technology is intended to improve the delamination toughness in composite laminates loaded in bending. In the first part of this study a numerical model was developed for analyzing composite structures. The 3-D finite element model was built with the ANSYS commercial software using 20-node solid and 8-node shell elements. The progressive damage modeling technique was used, allowing the prediction of delamination propagation in a laminate submitted to various loading modes. The model was validated for a plate under quasi-static traction load, and it was then used to simulate three-point bending tests. Secondly, carbon/epoxy composite panels were fabricated, with each panel containing unstitched and stitched specimens. Two different materials were used for the stitching thread: superelastic TiNi wires and Kevlar threads as a reference. Some stitched specimens were cut in slices in order to make some observations of the internal stitch using an optical microscope. Standardized low-velocity impact tests and compression after impact tests were carried out on stitched and unstitched specimens (ASTM D7136 and D7137). The Kevlar reinforcements have shown great performance in reducing the delaminated zone after impact, as well as in improving the residual compression strength. The TiNi reinforcements provided encouraging results during the impact tests, though being less effective than the Kevlar threads. During the compression after impact tests, only a slight difference could be measured between the TiNi-stitched and the unstitched specimens. Then the bending performance of the specimens was quantified experimentally by calculating the energy required to create a unit volume of damaged material (Gv, J/mm3). This metric is similar to the Strain Energy Release Rate (SERR) commonly used in studies on delamination. According to the experimental results, the damage resistance in three-point bending was not improved by the Kevlar reinforcements, despite the reduced damaged zone after the impact test. Indeed, when the strain energy in bending is relativized to the induced damaged volume during propagation, it turns out that the TiNi reinforcements are more effective than the Kevlar's for improving the damage resistance. Finally, the numerical study on the behavior of both types of stitched reinforcements allowed identifying subtle differences between those. Indeed, both stitching threads (TiNi and Kevlar) promoted the interlaminar propagation of the delamination during simulation of the bending test, with this behavior being less pronounced for the TiNi-stitched plate. However the Kevlar threads seemed more effective for stopping this propagation in the zones between the stitches. Keywords: composite materials, stitching, numerical model, shape memory alloy, three-point bending, low-velocity impact, ultrasound imaging.

Exploring Elephant Seals in New Jersey: Preschoolers Use Collaborative Multimedia Albums

ERIC Educational Resources Information Center

Fantozzi, Victoria B.

2012-01-01

VoiceThread is a website that allows users to create multimedia slideshows, or "threads," and then open these threads to other users for commentary or collaboration. This article shares the experiences of one multiage (3- to 5-year-olds) preschool classroom's use of VoiceThread. The purpose of the article is to introduce early childhood educators…

A C++ Thread Package for Concurrent and Parallel Programming

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jie Chen; William Watson

1999-11-01

Recently thread libraries have become a common entity on various operating systems such as Unix, Windows NT and VxWorks. Those thread libraries offer significant performance enhancement by allowing applications to use multiple threads running either concurrently or in parallel on multiprocessors. However, the incompatibilities between native libraries introduces challenges for those who wish to develop portable applications.

A multi-threaded version of MCFM

DOE Office of Scientific and Technical Information (OSTI.GOV)

Campbell, John M.; Ellis, R. Keith; Giele, Walter T.

We report on our findings modifying MCFM using OpenMP to implement multi-threading. By using OpenMP, the modified MCFM will execute on any processor, automatically adjusting to the number of available threads. We then modified the integration routine VEGAS to distribute the event evaluation over the threads, while combining all events at the end of every iteration to optimize the numerical integration. Furthermore, we took special care so that the results of the Monte Carlo integration were independent of the number of threads used, to facilitate the validation of the OpenMP version of MCFM.

Olivine-hosted melt inclusions record efficient mixing of mantle melts in continental flood basalt provinces

NASA Astrophysics Data System (ADS)

Jennings, E. S.; Gibson, S. A.; Maclennan, J.; Heinonen, J. S.

2017-12-01

Primitive melt inclusions trapped in various minerals found in global ridge settings have been shown to record highly variable magmatic compositions. Mantle melting is expected to be near-fractional, producing a wide range of melt compositions that must accumulate and mix in crustal magma chambers. In primitive rocks, the melt inclusion variability observed in major, trace and isotope geochemistry is consistent to the first order with partial melting of variably depleted mantle, and indicate that the host phases began to crystallise prior to the completion of melt aggregation and mixing. We present new major and trace element data from a large number of rehomogenised olivine-hosted melt inclusions from the Cretaceous Paraná-Etendeka and Jurassic Karoo continental flood basalt (CFB) provinces [1]. We show that the major element chemistry of the melt inclusions can be severely disrupted by the rehomogenisation process and, as a consequence, their initial compositions cannot easily be back-calculated. However, despite the age of the samples, the trace element geochemistry of the melt inclusions is well-preserved. Despite coming from near-liquidus olivines from primitive picrites and ferropicrites, the inclusions are remarkably homogeneous; none of the anticipated variability in incompatible trace element compositions is observed. When considered alongside literature data, it appears that variability in primitive melts - as recorded by melt inclusions - is low in CFBs and OIBs relative to ridge settings, e.g. Iceland. We suggest that the tectonic setting imposes a control on the mixing of mantle melts: hot, plume-derived melts generated beneath relatively thick lithosphere may be prone to efficient mixing, perhaps due to their low viscosity, long transport pathways, and/or a superliquidus emplacement temperature [1]. This interpretation is supported by the almost non-existent variability of olivine-hosted inclusions from ferropicrite samples: these magmas represents the deepest, hottest and lowest viscosity magma of all the samples considered. [1] Jennings E. S., Gibson S. A., Maclennan J. and Heinonen J. S. (2017) Deep mixing of mantle melts beneath continental flood basalt provinces: Constraints from olivine-hosted melt inclusions in primitive magmas. Geochimica et Cosmochimica Acta 196, 36-57.

Assimilation of Sea Surface Temperature in a doubly, two-way nested primitive equation model of the Ligurian Sea

NASA Astrophysics Data System (ADS)

Barth, A.; Alvera-Azcarate, A.; Rixen, M.; Beckers, J.-M.; Testut, C.-E.; Brankart, J.-M.; Brasseur, P.

2003-04-01

The GHER 3D primitive equation model is implemented with three different resolutions: a low resolution model (1/4^o) covering the whole Mediterranean Sea, an intermediate resolution model (1/20^o) of the Liguro-Provençal basin and a high resolution model (1/60^o) simulating the fine mesoscale structures in the Ligurian Sea. Boundary conditions and the averaged fields (feedback) are exchanged between two successive nesting levels. The model of the Ligurian Sea is also coupled with the assimilation package SESAM. It allows to assimilate satellite data and in situ observations using the local adaptative SEEK (Singular Evolutive Extended Kalman) filter. Instead of evolving the error space by the numerically expensive Lyapunov equation, a simplified algebraic equation depending on the misfit between observation and model forecast is used. Starting from the 1st January 1998 the low and intermediate resolution models are spun up for 18 months. The initial conditions for the Ligurian Sea are interpolated from the intermediate resolution model. The three models are then integrated until August 1999. During this period AVHRR Sea Surface Temperature of the Ligurian Sea is assimilated. The results are validated by using CTD and XBT profiles of the SIRENA cruise from the SACLANT Center. The overall objective of this study is pre-operational. It should help to identify limitations and weaknesses of forecasting methods and to suggest improvements of existing operational models.

Fixed Full Arches Supported by Tapered Implants with Knife-Edge Thread Design and Nanostructured, Calcium-Incorporated Surface: A Short-Term Prospective Clinical Study

PubMed Central

Bechara, Soheil; Lukosiunas, Algirdas; Kubilius, Ricardas

2017-01-01

Purpose. To evaluate implant survival, peri-implant bone loss, and complications affecting fixed full-arch (FFA) restorations supported by implants with a knife-edge thread design and nanostructured, calcium-incorporated surface. Methods. Between January 2013 and December 2015, all patients referred for implant-supported FFA restorations were considered for enrollment in this study. All patients received implants with a knife-edge thread design and nanostructured calcium-incorporated surface (Anyridge®, Megagen, South Korea) were restored with FFA restorations and enrolled in a recall program. The final outcomes were implant survival, peri-implant bone loss, biologic/prosthetic complications, and “complication-free” survival of restorations. Results. Twenty-four patients were selected. Overall, 215 implants were inserted (130 maxilla, 85 mandible), 144 in extraction sockets and 71 in healed ridges. Thirty-six FFAs were delivered (21 maxilla, 15 mandible): 27 were immediately loaded and 9 were conventionally loaded. The follow-up ranged from 1 to 3 years. Two fixtures failed, yielding an implant survival rate of 95.9% (patient-based). A few complications were registered, for a “complication-free” survival of restorations of 88.9%. Conclusions. FFA restorations supported by implants with a knife-edge thread design and nanostructured, calcium-incorporated surface are successful in the short term, with high survival and low complication rates; long-term studies are needed to confirm these outcomes. PMID:28246595

Thread-Like CMOS Logic Circuits Enabled by Reel-Processed Single-Walled Carbon Nanotube Transistors via Selective Doping.

PubMed

Heo, Jae Sang; Kim, Taehoon; Ban, Seok-Gyu; Kim, Daesik; Lee, Jun Ho; Jur, Jesse S; Kim, Myung-Gil; Kim, Yong-Hoon; Hong, Yongtaek; Park, Sung Kyu

2017-08-01

The realization of large-area electronics with full integration of 1D thread-like devices may open up a new era for ultraflexible and human adaptable electronic systems because of their potential advantages in demonstrating scalable complex circuitry by a simply integrated weaving technology. More importantly, the thread-like fiber electronic devices can be achieved using a simple reel-to-reel process, which is strongly required for low-cost and scalable manufacturing technology. Here, high-performance reel-processed complementary metal-oxide-semiconductor (CMOS) integrated circuits are reported on 1D fiber substrates by using selectively chemical-doped single-walled carbon nanotube (SWCNT) transistors. With the introduction of selective n-type doping and a nonrelief photochemical patterning process, p- and n-type SWCNT transistors are successfully implemented on cylindrical fiber substrates under air ambient, enabling high-performance and reliable thread-like CMOS inverter circuits. In addition, it is noteworthy that the optimized reel-coating process can facilitate improvement in the arrangement of SWCNTs, building uniformly well-aligned SWCNT channels, and enhancement of the electrical performance of the devices. The p- and n-type SWCNT transistors exhibit field-effect mobility of 4.03 and 2.15 cm 2 V -1 s -1 , respectively, with relatively narrow distribution. Moreover, the SWCNT CMOS inverter circuits demonstrate a gain of 6.76 and relatively good dynamic operation at a supply voltage of 5.0 V. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Requirements for implementing real-time control functional modules on a hierarchical parallel pipelined system

NASA Technical Reports Server (NTRS)

Wheatley, Thomas E.; Michaloski, John L.; Lumia, Ronald

1989-01-01

Analysis of a robot control system leads to a broad range of processing requirements. One fundamental requirement of a robot control system is the necessity of a microcomputer system in order to provide sufficient processing capability.The use of multiple processors in a parallel architecture is beneficial for a number of reasons, including better cost performance, modular growth, increased reliability through replication, and flexibility for testing alternate control strategies via different partitioning. A survey of the progression from low level control synchronizing primitives to higher level communication tools is presented. The system communication and control mechanisms of existing robot control systems are compared to the hierarchical control model. The impact of this design methodology on the current robot control systems is explored.

Genotype Specification Language.

PubMed

Wilson, Erin H; Sagawa, Shiori; Weis, James W; Schubert, Max G; Bissell, Michael; Hawthorne, Brian; Reeves, Christopher D; Dean, Jed; Platt, Darren

2016-06-17

We describe here the Genotype Specification Language (GSL), a language that facilitates the rapid design of large and complex DNA constructs used to engineer genomes. The GSL compiler implements a high-level language based on traditional genetic notation, as well as a set of low-level DNA manipulation primitives. The language allows facile incorporation of parts from a library of cloned DNA constructs and from the "natural" library of parts in fully sequenced and annotated genomes. GSL was designed to engage genetic engineers in their native language while providing a framework for higher level abstract tooling. To this end we define four language levels, Level 0 (literal DNA sequence) through Level 3, with increasing abstraction of part selection and construction paths. GSL targets an intermediate language based on DNA slices that translates efficiently into a wide range of final output formats, such as FASTA and GenBank, and includes formats that specify instructions and materials such as oligonucleotide primers to allow the physical construction of the GSL designs by individual strain engineers or an automated DNA assembly core facility.

Dual-Arm Generalized Compliant Motion With Shared Control

NASA Technical Reports Server (NTRS)

Backes, Paul G.

1994-01-01

Dual-Arm Generalized Compliant Motion (DAGCM) primitive computer program implementing improved unified control scheme for two manipulator arms cooperating in task in which both grasp same object. Provides capabilities for autonomous, teleoperation, and shared control of two robot arms. Unifies cooperative dual-arm control with multi-sensor-based task control and makes complete task-control capability available to higher-level task-planning computer system via large set of input parameters used to describe desired force and position trajectories followed by manipulator arms. Some concepts discussed in "A Generalized-Compliant-Motion Primitive" (NPO-18134).

Geographical distribution and risk assessment of persistent organic pollutants in golden threads (Nemipterus virgatus) from the northern South China Sea.

PubMed

Hao, Qing; Sun, Yu-Xin; Xu, Xiang-Rong; Yao, Zi-Wei; Wang, You-Shao; Zhang, Zai-Wang; Luo, Xiao-Jun; Mai, Bi-Xian

2015-10-01

Fish are often used as good bioindicators to monitor the occurrence of persistent organic pollutants (POPs) on different scales in recent years. Forty-five golden threads (Nemipterus virgatus) were collected from six sampling sites in the northern South China Sea (SCS) to investigate the geographical distribution of polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane and its metabolites (DDTs). Concentrations of PBDEs, PCBs, and DDTs ranged from 1.3-36.0, 2.3-76.5, 8.3-228 ng/g lipid weight, respectively. The highest PBDEs and DDTs concentrations were found in golden threads from Shantou, owing to the intensive electronic waste recycling activities and rapid development of agriculture. Samples from Haikou had the highest levels of PCBs, probably due to the existence of many shipbuilding yards in the past years. The concentrations of PBDEs and PCBs were found in a decreasing trend from east to west and from north to south, while DDTs concentrations had no obvious trend in the distribution. PCBs were the most prevalent contaminants in Xiamen and Yangjiang, while DDTs were the dominant compounds at the other four sampling sites. Different profiles of POPs at each sampling site may attribute to different pollution sources in the northern SCS. Ratios of (DDD + DDE)/DDTs in golden threads suggested the probability of fresh input of DDT in the northern SCS. The estimated daily intakes of PBDEs, PCBs and DDTs were 0.030-0.069, 0.167-0.258 and 0.105-1.88 ng/kg/day, respectively, which were significantly lower than the acceptable daily intake, suggesting that consumption of golden threads from the northern SCS would not subject the residents in the coastal areas of SCS to significant health risk.

Nutrient Deprivation Induces Property Variations in Spider Gluey Silk

PubMed Central

Blamires, Sean J.; Sahni, Vasav; Dhinojwala, Ali; Blackledge, Todd A.; Tso, I-Min

2014-01-01

Understanding the mechanisms facilitating property variability in biological adhesives may promote biomimetic innovations. Spider gluey silks such as the spiral threads in orb webs and the gumfoot threads in cobwebs, both of which comprise of an axial thread coated by glue, are biological adhesives that have variable physical and chemical properties. Studies show that the physical and chemical properties of orb web gluey threads change when spiders are deprived of food. It is, however, unknown whether gumfoot threads undergo similar property variations when under nutritional stress. Here we tested whether protein deprivation induces similar variations in spiral and gumfoot thread morphology and stickiness. We manipulated protein intake for the orb web spider Nephila clavipes and the cobweb spider Latrodectus hesperus and measured the diameter, glue droplet volume, number of droplets per mm, axial thread width, thread stickiness and adhesive energy of their gluey silks. We found that the gluey silks of both species were stickier when the spiders were deprived of protein than when the spiders were fed protein. In N. clavipes a concomitant increase in glue droplet volume was found. Load-extension curves showed that protein deprivation induced glue property variations independent of the axial thread extensions in both species. We predicted that changes in salt composition of the glues were primarily responsible for the changes in stickiness of the silks, although changes in axial thread properties might also contribute. We, additionally, showed that N. clavipes' glue changes color under protein deprivation, probably as a consequence of changes to its biochemical composition. PMID:24523902

[Mechanical behaviour of three types of surgical knots using 4/0 monofilament].

PubMed

Gil Santos, Luis; Más-Estellés, Jorge; Salmerón Sánchez, Manuel; Barrios, Carlos

2012-01-01

To experimentally study the behaviour of 4 types of monofilament with 3 knotting techniques, very often used in surgery, employing mechanical tests. Four 4/0 monofilaments were chosen, two of nylon, and the other two of polypropylene. Three types of knot designs were made with each thread. The first design (D-S-S) consisted of a double half-knot (D) followed by one single (S) in the opposite direction, a third S in turn in the opposite direction. The configuration of the second design was D-S-D, and the third, S-S-D. A mechanical fracture test was performed by stretching the thread at a rate of 4N/s, the force and deformation being recorded at intervals of 100 ms. There was a decrease in the force and deformation in the tests on threads with knots compared to threads without knots. In all cases the rupture of the thread occurred in the knot area, presumably due to damage caused to the thread during the knotting process. The D-S-D knot had the greatest resistance with polypropylene threads, and S-S-D provided the greatest resistance with nylon threads Polypropylene threads, with D-S-D knots, should be more indicated to suture tissues that have to support great forces and with little deformation of the suture (e.g., tendons). Nylon threads, with S-S-D knots, would be better indicated for tissues that have to support smaller forces and that require greater elasticity (e.g., skin). Copyright © 2011 AEC. Published by Elsevier Espana. All rights reserved.

Reshaping the Energy Landscape Transforms the Mechanism and Binding Kinetics of DNA Threading Intercalation.

PubMed

Clark, Andrew G; Naufer, M Nabuan; Westerlund, Fredrik; Lincoln, Per; Rouzina, Ioulia; Paramanathan, Thayaparan; Williams, Mark C

2018-02-06

Molecules that bind DNA via threading intercalation show high binding affinity as well as slow dissociation kinetics, properties ideal for the development of anticancer drugs. To this end, it is critical to identify the specific molecular characteristics of threading intercalators that result in optimal DNA interactions. Using single-molecule techniques, we quantify the binding of a small metal-organic ruthenium threading intercalator (Δ,Δ-B) and compare its binding characteristics to a similar molecule with significantly larger threading moieties (Δ,Δ-P). The binding affinities of the two molecules are the same, while comparison of the binding kinetics reveals significantly faster kinetics for Δ,Δ-B. However, the kinetics is still much slower than that observed for conventional intercalators. Comparison of the two threading intercalators shows that the binding affinity is modulated independently by the intercalating section and the binding kinetics is modulated by the threading moiety. In order to thread DNA, Δ,Δ-P requires a "lock mechanism", in which a large length increase of the DNA duplex is required for both association and dissociation. In contrast, measurements of the force-dependent binding kinetics show that Δ,Δ-B requires a large DNA length increase for association but no length increase for dissociation from DNA. This contrasts strongly with conventional intercalators, for which almost no DNA length change is required for association but a large DNA length change must occur for dissociation. This result illustrates the fundamentally different mechanism of threading intercalation compared with conventional intercalation and will pave the way for the rational design of therapeutic drugs based on DNA threading intercalation.

Metagenre on the WPA-L: Transitional Threads as Nexus for Micro/Macro-Level Discourse on the Dissertation

ERIC Educational Resources Information Center

Pantelides, Kate

2015-01-01

In Carolyn Miller's "Rhetorical Community: The Cultural Basis of Genre," she revisits her assertion that genres are cultural artifacts and questions the nature of the relationship between micro-level, individual speech acts, and macro-level genres and systems. To demonstrate this relationship, I analyze "meta-genre" accounts of…

Influence of Micro Threads Alteration on Osseointegration and Primary Stability of Implants: An FEA and In Vivo Analysis in Rabbits.

PubMed

Chowdhary, Ramesh; Halldin, Anders; Jimbo, Ryo; Wennerberg, Ann

2015-06-01

To describe the early bone tissue response to implants with and without micro threads designed to the full length of an oxidized titanium implant. A pair of two-dimensional finite element models was designed using a computer aided three-dimensional interactive application files of an implant model with micro threads in between macro threads and one without micro threads. Oxidized titanium implants with (test implants n=20) and without (control implants n=20) micro thread were prepared. A total of 12 rabbits were used and each received four implants. Insertion torque while implant placement and removal torque analysis after 4 weeks was performed in nine rabbits, and histomorphometric analysis in three rabbits, respectively. Finite element analysis showed less stress accumulation in test implant models with 31Mpa when compared with 62.2 Mpa in control implant model. Insertion and removal torque analysis did not show any statistical significance between the two implant designs. At 4 weeks, there was a significant difference between the two groups in the percentage of new bone volume and bone-to-implant contact in the femur (p< .05); however, not in the tibia. The effect of micro threads was prominent in the femur suggesting that micro threads promote bone formation. The stress distribution supported by the micro threads was especially effective in the cancellous bone. © 2013 Wiley Periodicals, Inc.

Unified structure theory of icosahedral quasicrystals: Evidence from neutron powder diffraction patterns that AlCrFeMnSi, AlCuLiMg, and TiNiFeSi icosahedral quasicrystals are twins of cubic crystals containing about 820 or 1012 atoms in a primitive unit cube

PubMed Central

Pauling, Linus

1988-01-01

A unified structure theory of icosahedral quasicrystals, combining the twinned-cubic-crystal theory and the Penrose-tiling-six-dimensional-projection theory, is described. Values of the primitive-cubic lattice constant for several quasicrystals are evaluated from x-ray and neutron diffraction data. The fact that the low-angle diffraction maxima can be indexed with cubic unit cells provides additional support for the twinned-cubic-crystal theory of icosahedral quasicrystals. PMID:16593990

Performance Analysis of Multilevel Parallel Applications on Shared Memory Architectures

NASA Technical Reports Server (NTRS)

Biegel, Bryan A. (Technical Monitor); Jost, G.; Jin, H.; Labarta J.; Gimenez, J.; Caubet, J.

2003-01-01

Parallel programming paradigms include process level parallelism, thread level parallelization, and multilevel parallelism. This viewgraph presentation describes a detailed performance analysis of these paradigms for Shared Memory Architecture (SMA). This analysis uses the Paraver Performance Analysis System. The presentation includes diagrams of a flow of useful computations.

Band warping, band non-parabolicity, and Dirac points in electronic and lattice structures

NASA Astrophysics Data System (ADS)

Resca, Lorenzo; Mecholsky, Nicholas A.; Pegg, Ian L.

2017-10-01

We illustrate at a fundamental level the physical and mathematical origins of band warping and band non-parabolicity in electronic and vibrational structures. We point out a robust presence of pairs of topologically induced Dirac points in a primitive-rectangular lattice using a p-type tight-binding approximation. We analyze two-dimensional primitive-rectangular and square Bravais lattices with implications that are expected to generalize to more complex structures. Band warping is shown to arise at the onset of a singular transition to a crystal lattice with a larger symmetry group, which allows the possibility of irreducible representations of higher dimensions, hence band degeneracy, at special symmetry points in reciprocal space. Band warping is incompatible with a multi-dimensional Taylor series expansion, whereas band non-parabolicities are associated with multi-dimensional Taylor series expansions to all orders. Still band non-parabolicities may merge into band warping at the onset of a larger symmetry group. Remarkably, while still maintaining a clear connection with that merging, band non-parabolicities may produce pairs of conical intersections at relatively low-symmetry points. Apparently, such conical intersections are robustly maintained by global topology requirements, rather than any local symmetry protection. For two p-type tight-binding bands, we find such pairs of conical intersections drifting along the edges of restricted Brillouin zones of primitive-rectangular Bravais lattices as lattice constants vary relatively to each other, until these conical intersections merge into degenerate warped bands at high-symmetry points at the onset of a square lattice. The conical intersections that we found appear to have similar topological characteristics as Dirac points extensively studied in graphene and other topological insulators, even though our conical intersections have none of the symmetry complexity and protection afforded by the latter more complex structures.

Thread scheduling for GPU-based OPC simulation on multi-thread

NASA Astrophysics Data System (ADS)

Lee, Heejun; Kim, Sangwook; Hong, Jisuk; Lee, Sooryong; Han, Hwansoo

2018-03-01

As semiconductor product development based on shrinkage continues, the accuracy and difficulty required for the model based optical proximity correction (MBOPC) is increasing. OPC simulation time, which is the most timeconsuming part of MBOPC, is rapidly increasing due to high pattern density in a layout and complex OPC model. To reduce OPC simulation time, we attempt to apply graphic processing unit (GPU) to MBOPC because OPC process is good to be programmed in parallel. We address some issues that may typically happen during GPU-based OPC simulation in multi thread system, such as "out of memory" and "GPU idle time". To overcome these problems, we propose a thread scheduling method, which manages OPC jobs in multiple threads in such a way that simulations jobs from multiple threads are alternatively executed on GPU while correction jobs are executed at the same time in each CPU cores. It was observed that the amount of GPU peak memory usage decreases by up to 35%, and MBOPC runtime also decreases by 4%. In cases where out of memory issues occur in a multi-threaded environment, the thread scheduler was used to improve MBOPC runtime up to 23%.

Final report on EURAMET.L-S21: `Supplementary comparison of parallel thread gauges'

NASA Astrophysics Data System (ADS)

Mudronja, Vedran; Šimunovic, Vedran; Acko, Bojan; Matus, Michael; Bánréti, Edit; István, Dicso; Thalmann, Rudolf; Lassila, Antti; Lillepea, Lauri; Bartolo Picotto, Gian; Bellotti, Roberto; Pometto, Marco; Ganioglu, Okhan; Meral, Ilker; Salgado, José Antonio; Georges, Vailleau

2015-01-01

The results of the comparison of parallel thread gauges between ten European countries are presented. Three thread plugs and three thread rings were calibrated in one loop. Croatian National Laboratory for Length (HMI/FSB-LPMD) acted as the coordinator and pilot laboratory of the comparison. Thread angle, thread pitch, simple pitch diameter and pitch diameter were measured. Pitch diameters were calibrated within 1a, 2a, 1b and 2b calibration categories in accordance with the EURAMET cg-10 calibration guide. A good agreement between the measurement results and differences due to different calibration categories are analysed in this paper. This comparison was a first EURAMET comparison of parallel thread gauges based on the EURAMET ctg-10 calibration guide, and has made a step towards the harmonization of future comparisons with the registration of CMC values for thread gauges. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCL, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Model for threading dislocations in metamorphic tandem solar cells on GaAs (001) substrates

NASA Astrophysics Data System (ADS)

Song, Yifei; Kujofsa, Tedi; Ayers, John E.

2018-02-01

We present an approximate model for the threading dislocations in III-V heterostructures and have applied this model to study the defect behavior in metamorphic triple-junction solar cells. This model represents a new approach in which the coefficient for second-order threading dislocation annihilation and coalescence reactions is considered to be determined by the length of misfit dislocations, LMD, in the structure, and we therefore refer to it as the LMD model. On the basis of this model we have compared the average threading dislocation densities in the active layers of triple junction solar cells using linearly-graded buffers of varying thicknesses as well as S-graded (complementary error function) buffers with varying thicknesses and standard deviation parameters. We have shown that the threading dislocation densities in the active regions of metamorphic tandem solar cells depend not only on the thicknesses of the buffer layers but on their compositional grading profiles. The use of S-graded buffer layers instead of linear buffers resulted in lower threading dislocation densities. Moreover, the threading dislocation densities depended strongly on the standard deviation parameters used in the S-graded buffers, with smaller values providing lower threading dislocation densities.

Effect of insertion torque on bone screw pullout strength.

PubMed

Lawson, K J; Brems, J

2001-05-01

The effect of insertion torque on the holding strength of 4.5-mm ASIF/AO cortical bone screws was studied in vitro. Screw holding strength was determined using an Instron materials testing machine (Bristol, United Kingdom) on 55 lamb femora and 30 human tibiocortical bone sections. Holding strength was defined as tensile stress at pullout with rapid loading to construct failure. Different insertion torques were tested, normalizing to the thickness of cortical bone specimen engaged. These represented low, intermediate, high, and thread-damaging insertion torque. All screws inserted with thread-damaging torque and single cortex engaging screws inserted to high torque tightening moments showed diminished holding strength. This loss of strength amounted to 40%-50% less than screws inserted with less torque.

Press-fit versus threaded acetabular cups in total hip arthroplasty: Functional and radiological results after five years.

PubMed

Ellenrieder, Martin; Bader, Rainer; Bergschmidt, Philipp; Mittelmeier, Wolfram

2016-03-01

Prospectively the outcome after total hip replacement with a new threaded acetabular cup design was compared to an established press-fit cup. After 1, 2 and 5 years, the 36-item Short Form Health Survey, Western Ontario and McMaster University Osteoarthritis Index and Harris Hip Score revealed no significant differences between the two groups (each group: n=42 patients), except for a higher Harris Hip Score in the threaded cup group after five years (p=0.02). After five years, one threaded cup had a mild radiolucent line without further signs of loosening. All other cups of both groups (98.6%) showed a full osseous integration. The cup inclination angle ranged from 41-58° (threaded cups) to 39-77° (press-fit cups). The new threaded cup provides equivalent clinical outcomes and osseous integration but more precise implant positioning compared to the press-fit design. No complications typically ascribed to threaded cups (acetabular fractures, bone resorption, nerve impairment) occurred.

Multithreading with separate data to improve the performance of Backpropagation method

NASA Astrophysics Data System (ADS)

Dhamma, Mulia; Zarlis, Muhammad; Budhiarti Nababan, Erna

2017-12-01

Backpropagation is one method of artificial neural network that can make a prediction for a new data with learning by supervised of the past data. The learning process of backpropagation method will become slow if we give too much data for backpropagation method to learn the data. Multithreading with a separate data inside of each thread are being used in order to improve the performance of backpropagtion method . Base on the research for 39 data and also 5 times experiment with separate data into 2 thread, the result showed that the average epoch become 6490 when using 2 thread and 453049 epoch when using only 1 thread. The most lowest epoch for 2 thread is 1295 and 1 thread is 356116. The process of improvement is caused by the minimum error from 2 thread that has been compared to take the weight and bias value. This process will be repeat as long as the backpropagation do learning.

Sensory processing and world modeling for an active ranging device

NASA Technical Reports Server (NTRS)

Hong, Tsai-Hong; Wu, Angela Y.

1991-01-01

In this project, we studied world modeling and sensory processing for laser range data. World Model data representation and operation were defined. Sensory processing algorithms for point processing and linear feature detection were designed and implemented. The interface between world modeling and sensory processing in the Servo and Primitive levels was investigated and implemented. In the primitive level, linear features detectors for edges were also implemented, analyzed and compared. The existing world model representations is surveyed. Also presented is the design and implementation of the Y-frame model, a hierarchical world model. The interfaces between the world model module and the sensory processing module are discussed as well as the linear feature detectors that were designed and implemented.

Effects of thread interruptions on tool pins in friction stir welding of AA6061

DOE PAGES

Reza-E-Rabby, Md.; Tang, Wei; Reynolds, Anthony P.

2017-06-21

In this paper, effects of pin thread and thread interruptions (flats) on weld quality and process response parameters during friction stir welding (FSW) of 6061 aluminium alloy were quantified. Otherwise, identical smooth and threaded pins with zero to four flats were adopted for FSW. Weldability and process response variables were examined. Results showed that threads with flats significantly improved weld quality and reduced in-plane forces. A three-flat threaded pin led to production of defect-free welds under all examined welding conditions. Spectral analyses of in-plane forces and weld cross-sectional analysis were performed to establish correlation among pin flats, force dynamics andmore » defect formation. Finally, the lowest in-plane force spectra amplitudes were consistently observed for defect-free welds.« less

Effects of thread interruptions on tool pins in friction stir welding of AA6061

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reza-E-Rabby, Md.; Tang, Wei; Reynolds, Anthony P.

In this paper, effects of pin thread and thread interruptions (flats) on weld quality and process response parameters during friction stir welding (FSW) of 6061 aluminium alloy were quantified. Otherwise, identical smooth and threaded pins with zero to four flats were adopted for FSW. Weldability and process response variables were examined. Results showed that threads with flats significantly improved weld quality and reduced in-plane forces. A three-flat threaded pin led to production of defect-free welds under all examined welding conditions. Spectral analyses of in-plane forces and weld cross-sectional analysis were performed to establish correlation among pin flats, force dynamics andmore » defect formation. Finally, the lowest in-plane force spectra amplitudes were consistently observed for defect-free welds.« less

Servicing a globally broadcast interrupt signal in a multi-threaded computer

DOEpatents

Attinella, John E.; Davis, Kristan D.; Musselman, Roy G.; Satterfield, David L.

2015-12-29

Methods, apparatuses, and computer program products for servicing a globally broadcast interrupt signal in a multi-threaded computer comprising a plurality of processor threads. Embodiments include an interrupt controller indicating in a plurality of local interrupt status locations that a globally broadcast interrupt signal has been received by the interrupt controller. Embodiments also include a thread determining that a local interrupt status location corresponding to the thread indicates that the globally broadcast interrupt signal has been received by the interrupt controller. Embodiments also include the thread processing one or more entries in a global interrupt status bit queue based on whether global interrupt status bits associated with the globally broadcast interrupt signal are locked. Each entry in the global interrupt status bit queue corresponds to a queued global interrupt.

Whole-Body Radiation Therapy, Systemic Chemotherapy, and High-Dose Chemotherapy Followed By Stem Cell Rescue in Treating Patients With Poor-Risk Ewing Sarcoma

ClinicalTrials.gov

2015-01-07

Adult Supratentorial Primitive Neuroectodermal Tumor (PNET); Ewing Sarcoma of Bone; Extraosseous Ewing Sarcoma; Metastatic Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Recurrent Childhood Supratentorial Primitive Neuroectodermal Tumor; Recurrent Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Untreated Childhood Supratentorial Primitive Neuroectodermal Tumor

VoiceThread as a Peer Review and Dissemination Tool for Undergraduate Research

NASA Astrophysics Data System (ADS)

Guertin, L. A.

2012-12-01

VoiceThread has been utilized in an undergraduate research methods course for peer review and final research project dissemination. VoiceThread (http://www.voicethread.com) can be considered a social media tool, as it is a web-based technology with the capacity to enable interactive dialogue. VoiceThread is an application that allows a user to place a media collection online containing images, audio, videos, documents, and/or presentations in an interface that facilitates asynchronous communication. Participants in a VoiceThread can be passive viewers of the online content or engaged commenters via text, audio, video, with slide annotations via a doodle tool. The VoiceThread, which runs across browsers and operating systems, can be public or private for viewing and commenting and can be embedded into any website. Although few university students are aware of the VoiceThread platform (only 10% of the students surveyed by Ng (2012)), the 2009 K-12 edition of The Horizon Report (Johnson et al., 2009) lists VoiceThread as a tool to watch because of the opportunities it provides as a collaborative learning environment. In Fall 2011, eleven students enrolled in an undergraduate research methods course at Penn State Brandywine each conducted their own small-scale research project. Upon conclusion of the projects, students were required to create a poster summarizing their work for peer review. To facilitate the peer review process outside of class, each student-created PowerPoint file was placed in a VoiceThread with private access to only the class members and instructor. Each student was assigned to peer review five different student posters (i.e., VoiceThread images) with the audio and doodle tools to comment on formatting, clarity of content, etc. After the peer reviews were complete, the students were allowed to edit their PowerPoint poster files for a new VoiceThread. In the new VoiceThread, students were required to video record themselves describing their research and taking the viewer through their poster in the VoiceThread. This new VoiceThread with their final presentations was open for public viewing but not public commenting. A formal assessment was not conducted on the student impact of using VoiceThread for peer review and final research presentations. From an instructional standpoint, requiring students to use audio for the peer review commenting seemed to result in lengthier and more detailed reviews, connected with specific poster features when the doodle tool was utilized. By recording themselves as a "talking head" for the final product, students were required to be comfortable and confident with presenting their research, similar to what would be expected at a conference presentation. VoiceThread is currently being tested in general education Earth science courses at Penn State Brandywine as a dissemination tool for classroom-based inquiry projects and recruitment tool for Earth & Mineral Science majors.

Discovering motion primitives for unsupervised grouping and one-shot learning of human actions, gestures, and expressions.

PubMed

Yang, Yang; Saleemi, Imran; Shah, Mubarak

2013-07-01

This paper proposes a novel representation of articulated human actions and gestures and facial expressions. The main goals of the proposed approach are: 1) to enable recognition using very few examples, i.e., one or k-shot learning, and 2) meaningful organization of unlabeled datasets by unsupervised clustering. Our proposed representation is obtained by automatically discovering high-level subactions or motion primitives, by hierarchical clustering of observed optical flow in four-dimensional, spatial, and motion flow space. The completely unsupervised proposed method, in contrast to state-of-the-art representations like bag of video words, provides a meaningful representation conducive to visual interpretation and textual labeling. Each primitive action depicts an atomic subaction, like directional motion of limb or torso, and is represented by a mixture of four-dimensional Gaussian distributions. For one--shot and k-shot learning, the sequence of primitive labels discovered in a test video are labeled using KL divergence, and can then be represented as a string and matched against similar strings of training videos. The same sequence can also be collapsed into a histogram of primitives or be used to learn a Hidden Markov model to represent classes. We have performed extensive experiments on recognition by one and k-shot learning as well as unsupervised action clustering on six human actions and gesture datasets, a composite dataset, and a database of facial expressions. These experiments confirm the validity and discriminative nature of the proposed representation.

Toward automated interpretation of integrated information: Managing "big data" for NDE

NASA Astrophysics Data System (ADS)

Gregory, Elizabeth; Lesthaeghe, Tyler; Holland, Stephen

2015-03-01

Large scale automation of NDE processes is rapidly maturing, thanks to recent improvements in robotics and the rapid growth of computer power over the last twenty years. It is fairly straightforward to automate NDE data collection itself, but the process of NDE remains largely manual. We will discuss three threads of technological needs that must be addressed before we are able to perform automated NDE. Spatial context, the first thread, means that each NDE measurement taken is accompanied by metadata that locates the measurement with respect to the 3D physical geometry of the specimen. In this way, the geometry of the specimen acts as a database key. Data context, the second thread, means that we record why the data was taken and how it was measured in addition to the NDE data itself. We will present our software tool that helps users interact with data in context, Databrowse. Condition estimation, the third thread, is maintaining the best possible knowledge of the condition (serviceability, degradation, etc.) of an object or part. In the NDE context, we can prospectively use Bayes' Theorem to integrate the data from each new NDE measurement with prior knowledge. These tools, combined with robotic measurements and automated defect analysis, will provide the information needed to make high-level life predictions and focus NDE measurements where they are needed most.

Properties of Massive Stars in Primitive Galaxies

NASA Technical Reports Server (NTRS)

Heap, Sara

2012-01-01

According to R. Dave, the phases of galaxy formation are distinguished by their halo mass and governing feedback mechanism. Galaxies in the birth phase (our "primitive galaxies") have a low halo mass (M<10(exp 9) Msun); and star formation is affected by photoionizing radiation of massive stars. In contrast, galaxies in the growth phase (e.g. Lyman Break galaxies) are more massive (M=10(exp 9)-10(exp 12) Msun); star formation is fueled by cold accretion but modulated by strong outflows from massive stars. I Zw 18 is a local blue, compact dwarf galaxy that meets the requirements for a birth-phase galaxy: halo mass <10(exp 9) Msun, strong photo ionizing radiation, no galactic outflow, and very low metallicity, log(O/H)=7.2. We will describe the properties of massive stars in I Zw 18 based on analysis of ultraviolet spectra obtained with HST.

Biomechanical investigation of thread designs and interface conditions of zirconia and titanium dental implants with bone: three-dimensional numeric analysis.

PubMed

Fuh, Lih-Jyh; Hsu, Jui-Ting; Huang, Heng-Li; Chen, Michael Y C; Shen, Yen-Wen

2013-01-01

Bone stress and interfacial sliding at the bone-implant interface (BII) were analyzed in zirconia and titanium implants with various thread designs and interface conditions (bonded BII and contact BIIs with different frictional coefficients) for both conventional and immediately loaded treatments. A total of 18 finite element models comprising two implant materials (zirconia and titanium), three thread designs (different shapes and pitches), and three interface conditions (bonded and contact BIIs) were analyzed to assess the effects on bone stresses and on sliding at the BII. The material properties of the bone model were anisotropic, and a lateral force of 130 N was applied as the loading condition. In the immediately loaded implant, the stress was highly concentrated at one site of the peri-implant bone. The peak bone stress was more than 20% lower in zirconia implants than in titanium implants for a bonded BII and 14% to 20% lower for a contact BII. The bone stresses did not differ significantly between implants with V-shaped threads and square threads. However, sliding at the BII was more than 25% lower with square-thread implants than with V-shaped-thread implants for titanium implants and 36% lower for zirconia implants. Reducing the thread size and pitch in cortical bone (via two V-shaped threads with different pitches) decreased the bone stress by 13%. Increasing the frictional coefficient reduced sliding at the BII in both zirconia and titanium implants. As an implant material, zirconia can reduce the bone stress in the crestal cortical region. Bone stress and sliding at the BII are heavily dependent on the thread design and the frictional coefficient at the BII of immediately loaded implants.

TENOGENIC DIFFERENTIATION OF HUMAN MSCs INDUCED BY THE TOPOGRAPHY OF ELECTROCHEMICALLY ALIGNED COLLAGEN THREADS

PubMed Central

Kishore, Vipuil; Bullock, Whitney; Sun, Xuanhao; Van Dyke, William Scott; Akkus, Ozan

2011-01-01

Topographical cues from the extracellular microenvironment can influence cellular activity including proliferation and differentiation. Information on the effects of material topography on tenogenic differentiation of human mesenchymal stem cells (human MSCs) is limited. A methodology using the principles of isoelectric focusing has previously been developed in our laboratory to synthesize electrochemically aligned collagen (ELAC) threads that mimics the packing density, alignment and strength of collagen dense connective tissues. In the current study, human MSCs were cultured on ELAC and randomly-oriented collagen threads and the effect of collagen orientation on cell morphology, proliferation and tenogenic differentiation was investigated. The results indicate that higher rates of proliferation were observed on randomly oriented collagen threads compared to ELAC threads. On the other hand, tendon specific markers such as scleraxis, tenomodulin, tenascin-C and collagen-III were significantly increased on ELAC threads compared to randomly oriented collagen threads. Additionally, osteocalcin, a specific marker of bone differentiation was suppressed on ELAC threads. Previous studies have reported that BMP-12 is a key growth factor to induce tenogenic differentiation of human MSCs. To evaluate the synergistic effect of BMP-12 and collagen orientation, human MSCs were cultured on ELAC threads in culture medium supplemented with and without BMP-12. The results revealed that BMP-12 did not have an additional effect on the tenogenic differentiation of human MSCs on ELAC threads. Together, these results suggest that ELAC induces tenogenic differentiation of human MSCs by presenting an aligned and dense collagen substrate, akin to the tendon itself. In conclusion, ELAC has a significant potential to be used as a tendon replacement and in the development of an osteotendinous construct towards the regeneration of bone-tendon interfaces. PMID:22177622

Bioglass incorporation improves mechanical properties and enhances cell-mediated mineralization on electrochemically aligned collagen threads.

PubMed

Nijsure, Madhura P; Pastakia, Meet; Spano, Joseph; Fenn, Michael B; Kishore, Vipuil

2017-09-01

Bone tissue engineering mandates the development of a functional scaffold that mimics the physicochemical properties of native bone. Bioglass 45S5 (BG) is a highly bioactive material known to augment bone formation and restoration. Hybrid scaffolds fabricated using collagen type I and BG resemble the organic and inorganic composition of the bone extracellular matrix and hence have been extensively investigated for bone tissue engineering applications. However, collagen-BG scaffolds developed thus far do not recapitulate the aligned structure of collagen found in native bone. In this study, an electrochemical fabrication method was employed to synthesize BG-incorporated electrochemically aligned collagen (BG-ELAC) threads that are compositionally similar to native bone. Further, aligned collagen fibrils within BG-ELAC threads mimic the anisotropic arrangement of collagen fibrils in native bone. The effect of BG incorporation on the mechanical properties and cell-mediated mineralization on ELAC threads was investigated. The results indicated that BG can be successfully incorporated within ELAC threads, without disturbing collagen fibril alignment. Further, BG incorporation significantly increased the ultimate tensile stress (UTS) and modulus of ELAC threads (p < 0.05). SBF conditioning showed extensive mineralization on BG-ELAC threads that increased over time demonstrating the bone bioactivity of BG-ELAC threads. Additionally, BG incorporation into ELAC threads resulted in increased cell proliferation (p < 0.05) and deposition of a highly dense and continuous mineralized matrix. In conclusion, incorporation of BG into ELAC threads is a viable strategy for the development of an osteoconductive material for bone tissue engineering applications. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2429-2440, 2017. © 2017 Wiley Periodicals, Inc.

Using all of your CPU's in HIPE

NASA Astrophysics Data System (ADS)

Jacobson, J. D.; Fadda, D.

2012-09-01

Modern computer architectures increasingly feature multi-core CPU's. For example, the MacbookPro features the Intel quad-core i7 processors. Through the use of hyper-threading, where each core can execute two threads simultaneously, the quad-core i7 can support eight simultaneous processing threads. All this on your laptop! This CPU power can now be put into service by scientists to perform data reduction tasks, but only if the software has been designed to take advantage of the multiple processor architectures. Up to now, software written for Herschel data reduction (HIPE), written in Jython and JAVA, is single-threaded and can only utilize a single processor. Users of HIPE do not get any advantage from the additional processors. Why not put all of the CPU resources to work reducing your data? We present a multi-threaded software application that corrects long-term transients in the signal from the PACS unchopped spectroscopy line scan mode. In this poster, we present a multi-threaded software framework to achieve performance improvements from parallel execution. We will show how a task to correct transients in the PACS Spectroscopy Pipeline for the un-chopped line scan mode, has been threaded. This computation-intensive task uses either a one-parameter or a three parameter exponential function, to characterize the transient. The task uses a JAVA implementation of Minpack, translated from the C (Moshier) and IDL (Markwardt) by the authors, to optimize the correction parameters. We also explain how to determine if a task can benefit from threading (Amdahl's Law), and if it is safe to thread. The design and implementation, using the JAVA concurrency package completions service is described. Pitfalls, timing bugs, thread safety, resource control, testing and performance improvements are described and plotted.

Using a source-to-source transformation to introduce multi-threading into the AliRoot framework for a parallel event reconstruction

NASA Astrophysics Data System (ADS)

Lohn, Stefan B.; Dong, Xin; Carminati, Federico

2012-12-01

Chip-Multiprocessors are going to support massive parallelism by many additional physical and logical cores. Improving performance can no longer be obtained by increasing clock-frequency because the technical limits are almost reached. Instead, parallel execution must be used to gain performance. Resources like main memory, the cache hierarchy, bandwidth of the memory bus or links between cores and sockets are not going to be improved as fast. Hence, parallelism can only result into performance gains if the memory usage is optimized and the communication between threads is minimized. Besides concurrent programming has become a domain for experts. Implementing multi-threading is error prone and labor-intensive. A full reimplementation of the whole AliRoot source-code is unaffordable. This paper describes the effort to evaluate the adaption of AliRoot to the needs of multi-threading and to provide the capability of parallel processing by using a semi-automatic source-to-source transformation to address the problems as described before and to provide a straight-forward way of parallelization with almost no interference between threads. This makes the approach simple and reduces the required manual changes in the code. In a first step, unconditional thread-safety will be introduced to bring the original sequential and thread unaware source-code into the position of utilizing multi-threading. Afterwards further investigations have to be performed to point out candidates of classes that are useful to share amongst threads. Then in a second step, the transformation has to change the code to share these classes and finally to verify if there are anymore invalid interferences between threads.

Shared prefetching to reduce execution skew in multi-threaded systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eichenberger, Alexandre E; Gunnels, John A

Mechanisms are provided for optimizing code to perform prefetching of data into a shared memory of a computing device that is shared by a plurality of threads that execute on the computing device. A memory stream of a portion of code that is shared by the plurality of threads is identified. A set of prefetch instructions is distributed across the plurality of threads. Prefetch instructions are inserted into the instruction sequences of the plurality of threads such that each instruction sequence has a separate sub-portion of the set of prefetch instructions, thereby generating optimized code. Executable code is generated basedmore » on the optimized code and stored in a storage device. The executable code, when executed, performs the prefetches associated with the distributed set of prefetch instructions in a shared manner across the plurality of threads.« less

Role of Superintendent in District Turnaround

ERIC Educational Resources Information Center

Evans, James, Jr.

2014-01-01

The purpose of this research study was to evaluate the role of the superintendent in the turnaround process in persistently low achieving school districts. This research identified common threads, principles, and suggestions on turnaround processes and the role of the superintendent through examination of research on leadership and school…

Tissue reactions to modern suturing material in colorectal surgery.

PubMed

Molokova, O A; Kecherukov, A I; Aliev, F Sh; Chernov, I A; Bychkov, V G; Kononov, V P

2007-06-01

Morphological changes in the wall of the large intestine were studied after its manual suturing by a double-row interrupted suture with modern suture threads. Light and scanning electron microscopy showed "fuse properties" and "sawing effect" of polyfilament twisted threads (e.g. vicryl). Monofilament threads were free from these drawbacks and therefore were preferable. Metal elastic threads on the basis of titanium-nickelide alloys caused no inflammatory changes in tissues.

FR/HR Sewing Thread

DTIC Science & Technology

2015-09-01

position unless so designated by other authorized documents. Citation of trade names in this report does not constitute an official endorsement or...project to design and develop a Fire Resistant (FR) and Heat Resistant (HR) sewing thread. The main goal of the project is to produce sewing threads made...addresses the design , development and testing of various Fire Resistant (FR)/Heat Resistant (HR) sewing threads for US Army applications. Such a sewing

Advanced Numerical Techniques of Performance Evaluation. Volume 1

DTIC Science & Technology

1990-06-01

system scheduling3thread. The scheduling thread then runs any other ready thread that can be found. A thread can only sleep or switch out on itself...Polychronopoulos and D.J. Kuck. Guided Self- Scheduling : A Practical Scheduling Scheme for Parallel Supercomputers. IEEE Transactions on Computers C...Kuck 1987] C.D. Polychronopoulos and D.J. Kuck. Guided Self- Scheduling : A Practical Scheduling Scheme for Parallel Supercomputers. IEEE Trans. on Comp

Mechanical properties of silk of the Australian golden orb weavers Nephila pilipes and Nephilaplumipes.

PubMed

Kerr, Genevieve G; Nahrung, Helen F; Wiegand, Aaron; Kristoffersen, Joanna; Killen, Peter; Brown, Cameron; Macdonald, Joanne

2018-02-22

Silks from orb-weaving spiders are exceptionally tough, producing a model polymer for biomimetic fibre development. The mechanical properties of naturally spun silk threads from two species of Australian orb-weavers, Nephila pilipes and Nephila plumipes , were examined here in relation to overall thread diameter, the size and number of fibres within threads, and spider size. N. pilipes , the larger of the two species, had significantly tougher silk with higher strain capacity than its smaller congener, producing threads with average toughness of 150 MJ m -3 , despite thread diameter, mean fibre diameter and number of fibres per thread not differing significantly between the two species. Within N. pilipes , smaller silk fibres were produced by larger spiders, yielding tougher threads. In contrast, while spider size was correlated with thread diameter in N. plumipes , there were no clear patterns relating to silk toughness, which suggests that the differences in properties between the silk of the two species arise through differing molecular structure. Our results support previous studies that found that the mechanical properties of silk differ between distantly related spider species, and extends on that work to show that the mechanical and physical properties of silk from more closely related species can also differ remarkably. © 2018. Published by The Company of Biologists Ltd.

Plasma treatments of wool fiber surface for microfluidic applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jeon, So-Hyoun; Hwang, Ki-Hwan; Lee, Jin Su

Highlights: • We used atmospheric plasma for tuning the wettability of wool fibers. • The wicking rates of the wool fibers increased with increasing treatment time. • The increasing of wettability results in removement of fatty acid on the wool surface. - Abstract: Recent progress in health diagnostics has led to the development of simple and inexpensive systems. Thread-based microfluidic devices allow for portable and inexpensive field-based technologies enabling medical diagnostics, environmental monitoring, and food safety analysis. However, controlling the flow rate of wool thread, which is a very important part of thread-based microfluidic devices, is quite difficult. For thismore » reason, we focused on thread-based microfluidics in the study. We developed a method of changing the wettability of hydrophobic thread, including wool thread. Thus, using natural wool thread as a channel, we demonstrate herein that the manipulation of the liquid flow, such as micro selecting and micro mixing, can be achieved by applying plasma treatment to wool thread. In addition to enabling the flow control of the treated wool channels consisting of all natural substances, this procedure will also be beneficial for biological sensing devices. We found that wools treated with various gases have different flow rates. We used an atmospheric plasma with O{sub 2}, N{sub 2} and Ar gases.« less

Identification of the primary compensating defect level responsible for determining blocking voltage of vertical GaN power diodes

DOE PAGES

King, M. P.; Kaplar, R. J.; Dickerson, J. R.; ...

2016-10-31

Electrical performance and characterization of deep levels in vertical GaN P-i-N diodes grown on low threading dislocation density (~10 4 –10 6 cm –2) bulk GaN substrates are investigated. The lightly doped n drift region of these devices is observed to be highly compensated by several prominent deep levels detected using deep level optical spectroscopy at E c-2.13, 2.92, and 3.2 eV. A combination of steady-state photocapacitance and lighted capacitance-voltage profiling indicates the concentrations of these deep levels to be N t = 3 × 10 12, 2 × 10 15, and 5 × 10 14 cm –3, respectively. Themore » E c-2.92 eV level is observed to be the primary compensating defect in as-grown n-type metal-organic chemical vapor deposition GaN, indicating this level acts as a limiting factor for achieving controllably low doping. The device blocking voltage should increase if compensating defects reduce the free carrier concentration of the n drift region. Understanding the incorporation of as-grown and native defects in thick n-GaN is essential for enabling large V BD in the next-generation wide-bandgap power semiconductor devices. Furthermore, controlling the as-grown defects induced by epitaxial growth conditions is critical to achieve blocking voltage capability above 5 kV.« less

Urban Forestry Laboratory Exercises for Elementary, Middle and High School Students.

ERIC Educational Resources Information Center

Kupkowski, Gary; And Others

The curriculum in this program has been developed for the elementary, middle, and high school levels. Each level builds on the other, and forms a "thread of skills" that are upgraded at each level. The program is divided into two components. The first component is for the development of a school arboretum, tree walk, and herbarium. The second…

Solar Filament Longitudinal Oscillations along a Magnetic Field Tube with Two Dips

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhou Yu-Hao; Zhang Li-Yue; Ouyang, Y.

Large-amplitude longitudinal oscillations of solar filaments have been observed and explored for more than ten years. Previous studies are mainly based on the one-dimensional rigid flux tube model with a single magnetic dip. However, it has been noted that there might be two magnetic dips, and hence two threads, along one magnetic field line. Following previous work, we intend to investigate the kinematics of the filament longitudinal oscillations when two threads are magnetically connected, which is done by solving one-dimensional radiative hydrodynamic equations with the numerical code MPI-AMRVAC. Two different types of perturbations are considered, and the difference from previousmore » works resulting from the interaction of the two filament threads is investigated. We find that even with the inclusion of the thread–thread interaction, the oscillation period is modified weakly, by at most 20% compared to the traditional pendulum model with one thread. However, the damping timescale is significantly affected by the thread–thread interaction. Hence, we should take it into account when applying the consistent seismology to the filaments where two threads are magnetically connected.« less

[A novel method based on Y-shaped cotton-polyester thread microfluidic channel].

PubMed

Wang, Lu; Shi, Yan-ru; Yan, Hong-tao

2014-08-01

A novel method based on Y-shaped microfluidic channel was firstly proposed in this study. The microfluidic channel was made of two cotton-polyester threads based on the capillary effect of cotton-polyester threads for the determination solutions. A special device was developed to fix the Y-shaped microfluidic channel by ourselves, through which the length and the tilt angle of the channel can be adjusted as requested. The spectrophotometry was compared with Scan-Adobe Photoshop software processing method. The former had a lower detection limit while the latter showed advantages in both convenience and fast operations and lower amount of samples. The proposed method was applied to the determination of nitrite. The linear ranges and detection limits are 1.0-70 micromol x L(-1), 0.66 micromol x L(-1) (spectrophotometry) and 50-450 micromol x L(-1), 45.10 micromol x L(-1) (Scan-Adobe Photoshop software processing method) respectively. This method has been successfully used to the determination of nitrite in soil samples and moat water with recoveries between 96.7% and 104%. It was proved that the proposed method was a low-cost, rapid and convenient analytical method with extensive application prospect.

Exploring the Effect of Scripted Roles on Cognitive Presence in Asynchronous Online Discussions

ERIC Educational Resources Information Center

Olesova, Larisa; Slavin, Margaret; Lim, Jieun

2016-01-01

The purpose of this study was to identify the effect of scripted roles on students' level of cognitive presence in asynchronous online threaded discussions. A quantitative content analysis was used to investigate: (1) what level of cognitive presence is achieved by students' assigned roles in asynchronous online discussions; (2) differences…

View from second level looking down on embedded weld strips ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

View from second level looking down on embedded weld strips and plugged, threaded anchors in the foundation slab. These were put in place to assist in adapting to future configurations of the test stand. - Marshall Space Flight Center, Saturn V Dynamic Test Facility, East Test Area, Huntsville, Madison County, AL

Roofline model toolkit: A practical tool for architectural and program analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lo, Yu Jung; Williams, Samuel; Van Straalen, Brian

We present preliminary results of the Roofline Toolkit for multicore, many core, and accelerated architectures. This paper focuses on the processor architecture characterization engine, a collection of portable instrumented micro benchmarks implemented with Message Passing Interface (MPI), and OpenMP used to express thread-level parallelism. These benchmarks are specialized to quantify the behavior of different architectural features. Compared to previous work on performance characterization, these microbenchmarks focus on capturing the performance of each level of the memory hierarchy, along with thread-level parallelism, instruction-level parallelism and explicit SIMD parallelism, measured in the context of the compilers and run-time environments. We also measuremore » sustained PCIe throughput with four GPU memory managed mechanisms. By combining results from the architecture characterization with the Roofline model based solely on architectural specifications, this work offers insights for performance prediction of current and future architectures and their software systems. To that end, we instrument three applications and plot their resultant performance on the corresponding Roofline model when run on a Blue Gene/Q architecture.« less

Innovative Technique for the Placement of the Drainage Tube for Microendoscopic Spinal Decompression.

PubMed

Mizuno, Kentaro; Mikami, Yasuo; Hase, Hitoshi; Ikeda, Takumi; Nagae, Masateru; Tonomura, Hitoshi; Shirai, Toshiharu; Fujiwara, Hiroyoshi; Kubo, Toshikazu

2017-02-01

A technical note and retrospective study. The objectives were to describe a new method of drainage tube placement during microendoscopic spinal decompression, and compare the positioning and fluid discharge obtained with this method and the conventional method. To prevent postoperative epidural hematoma after microendoscopic decompression, a drainage tube must be placed in a suitable location. However, the narrow operative field makes precise control of the position of the tube technically difficult. We developed a method to reliably place the tube in the desired location. We use a Deschamps aneurysm needle with a slightly curved tip, which we call a drain passer. With the microendoscope in position, the drain passer, with a silk thread passed through the eye at the needle tip, is inserted percutaneously into the endoscopic field of view. The drainage tube is passed through the loop of silk thread protruding from the inside of the tubular retractor, and the thread is pulled to the outside, guiding the end of the drainage tube into the wound. This method was used in 23 cases at 44 intervertebral levels (drain passer group), and the conventional method in 20 cases at 32 intervertebral levels (conventional group). Postoperative plain radiographs were taken, and the amount of fluid discharge at postoperative hour 24 was measured. Drainage tube positioning was favorable at 43 intervertebral levels (97.7%) in the drain passer group and 26 intervertebral levels (81.3%) in the conventional group. Mean fluid discharge was 58.4±32.2 g in the drain passer group and 38.4±23.0 g in the conventional group. Positioning was significantly better and fluid discharge was significantly greater in the drain passer group. The results indicate that this method is a useful drainage tube placement technique for preventing postoperative epidural hematoma.

Multicore Challenges and Benefits for High Performance Scientific Computing

DOE PAGES

Nielsen, Ida M. B.; Janssen, Curtis L.

2008-01-01

Until recently, performance gains in processors were achieved largely by improvements in clock speeds and instruction level parallelism. Thus, applications could obtain performance increases with relatively minor changes by upgrading to the latest generation of computing hardware. Currently, however, processor performance improvements are realized by using multicore technology and hardware support for multiple threads within each core, and taking full advantage of this technology to improve the performance of applications requires exposure of extreme levels of software parallelism. We will here discuss the architecture of parallel computers constructed from many multicore chips as well as techniques for managing the complexitymore » of programming such computers, including the hybrid message-passing/multi-threading programming model. We will illustrate these ideas with a hybrid distributed memory matrix multiply and a quantum chemistry algorithm for energy computation using Møller–Plesset perturbation theory.« less

High-Level Data Races

NASA Technical Reports Server (NTRS)

Artho, Cyrille; Havelund, Klaus; Biere, Armin; Koga, Dennis (Technical Monitor)

2003-01-01

Data races are a common problem in concurrent and multi-threaded programming. They are hard to detect without proper tool support. Despite the successful application of these tools, experience shows that the notion of data race is not powerful enough to capture certain types of inconsistencies occurring in practice. In this paper we investigate data races on a higher abstraction layer. This enables us to detect inconsistent uses of shared variables, even if no classical race condition occurs. For example, a data structure representing a coordinate pair may have to be treated atomically. By lifting the meaning of a data race to a higher level, such problems can now be covered. The paper defines the concepts view and view consistency to give a notation for this novel kind of property. It describes what kinds of errors can be detected with this new definition, and where its limitations are. It also gives a formal guideline for using data structures in a multi-threading environment.

The interaction between vegetation and channel dynamics based on experimental findings

NASA Astrophysics Data System (ADS)

Teske, R.; Van Dijk, W. M.; Van De Lageweg, W.; Kleinhans, M. G.

2012-12-01

Strong feedbacks exist between river channel dynamics, floodplain development and riparian vegetation. Several experimental studies showed how uniformly sown vegetation causes a shift from a braided river to a single-thread and sometimes meandering river. The objective of this study is to test what the effect of fluvially distributed seeds and vegetation settling is on channel pattern change and channel dynamics. The experiments were carried out in a flume of 3 m wide and 10 m long. We tested where the vegetation deposited in a braided and meandering river and how the morphology changed. We used a simple hydrograph of 0.25 hour high flow and 3.75 hour low flow, where alfalfa seeds were added during high flow. The bed sediment consisted of a poorly sorted sediment mixture ranging from fine sand to fine gravel. The evolution was recorded by a high-resolution laser-line scanner and a Digital Single Lens Reflex (DSLR) camera used for channel floodplain segmentation, water depth approximation and vegetation distribution. In an initially braided river, vegetation settled on the higher banks and stabilized the banks. In an initially meandering river, vegetation settled in the inner scrolls, and also on the outer banks when water level exceeded bankfull conditions. In agreement with earlier work, the outer bank was stabilized; erosion rate decreased and bends became sharper. The inner bend vegetation stabilized a part of the point bar and hydraulic resistance of the vegetation steered water in the channel and to the non-vegetated part of the inner bend. As result the meander bend became braided as water flows along the vegetation. Vegetation formed patches that grew over time and reduced channel dynamics. We conclude that self-settling vegetation decreased local bank erosion and that vegetated islands leads to a multi-thread system instead of single-threaded.

Screw-Thread Inserts As Temporary Flow Restrictors

NASA Technical Reports Server (NTRS)

Trimarchi, Paul

1992-01-01

Coil-spring screw-thread inserts found useful as temporary flow restrictors. Inserts placed in holes through which flow restricted, effectively reducing cross sections available for flow. Friction alone holds inserts against moderate upstream pressures. Use of coil-spring thread inserts as flow restrictors conceived as inexpensive solution to problem of adjusting flow of oxygen through orifices in faceplate into hydrogen/oxygen combustion chamber. Installation and removal of threaded inserts gentle enough not to deform orifice tubes.

Asymptotic investigations into the `fluid mechanical sewing machine'

NASA Astrophysics Data System (ADS)

Blount, Maurice; Lister, John

2008-11-01

The fall of a slender viscous thread from a nozzle onto a moving horizontal belt exhibits a wide range of behaviour. Steady motion is observed above a critical belt speed. Below this speed the thread undergoes a buckling instability, and lays down on the belt a variety of stable, periodic patterns referred to as a `fluid mechanical sewing machine'. We expand on previous theoretical progress [1] by including the effects arising from the resistance of the thread to bending. While the bending resistance of a slender viscous thread is small, under certain circumstances it has a dominant effect. We work in the asymtotic limit of a slender thread, and investigate the full range of steady solutions. An asymptotic refinement to the estimate derived in [1] for the onset of buckling instability is presented, and the behaviour of the thread near onset is discussed. [1] S. Chiu-Webster & J.R. Lister, J. Fluid Mech. 569, 89-111.

Cpu/gpu Computing for AN Implicit Multi-Block Compressible Navier-Stokes Solver on Heterogeneous Platform

NASA Astrophysics Data System (ADS)

Deng, Liang; Bai, Hanli; Wang, Fang; Xu, Qingxin

2016-06-01

CPU/GPU computing allows scientists to tremendously accelerate their numerical codes. In this paper, we port and optimize a double precision alternating direction implicit (ADI) solver for three-dimensional compressible Navier-Stokes equations from our in-house Computational Fluid Dynamics (CFD) software on heterogeneous platform. First, we implement a full GPU version of the ADI solver to remove a lot of redundant data transfers between CPU and GPU, and then design two fine-grain schemes, namely “one-thread-one-point” and “one-thread-one-line”, to maximize the performance. Second, we present a dual-level parallelization scheme using the CPU/GPU collaborative model to exploit the computational resources of both multi-core CPUs and many-core GPUs within the heterogeneous platform. Finally, considering the fact that memory on a single node becomes inadequate when the simulation size grows, we present a tri-level hybrid programming pattern MPI-OpenMP-CUDA that merges fine-grain parallelism using OpenMP and CUDA threads with coarse-grain parallelism using MPI for inter-node communication. We also propose a strategy to overlap the computation with communication using the advanced features of CUDA and MPI programming. We obtain speedups of 6.0 for the ADI solver on one Tesla M2050 GPU in contrast to two Xeon X5670 CPUs. Scalability tests show that our implementation can offer significant performance improvement on heterogeneous platform.

Expressing Parallelism with ROOT

NASA Astrophysics Data System (ADS)

Piparo, D.; Tejedor, E.; Guiraud, E.; Ganis, G.; Mato, P.; Moneta, L.; Valls Pla, X.; Canal, P.

2017-10-01

The need for processing the ever-increasing amount of data generated by the LHC experiments in a more efficient way has motivated ROOT to further develop its support for parallelism. Such support is being tackled both for shared-memory and distributed-memory environments. The incarnations of the aforementioned parallelism are multi-threading, multi-processing and cluster-wide executions. In the area of multi-threading, we discuss the new implicit parallelism and related interfaces, as well as the new building blocks to safely operate with ROOT objects in a multi-threaded environment. Regarding multi-processing, we review the new MultiProc framework, comparing it with similar tools (e.g. multiprocessing module in Python). Finally, as an alternative to PROOF for cluster-wide executions, we introduce the efforts on integrating ROOT with state-of-the-art distributed data processing technologies like Spark, both in terms of programming model and runtime design (with EOS as one of the main components). For all the levels of parallelism, we discuss, based on real-life examples and measurements, how our proposals can increase the productivity of scientists.

Expressing Parallelism with ROOT

DOE Office of Scientific and Technical Information (OSTI.GOV)

Piparo, D.; Tejedor, E.; Guiraud, E.

The need for processing the ever-increasing amount of data generated by the LHC experiments in a more efficient way has motivated ROOT to further develop its support for parallelism. Such support is being tackled both for shared-memory and distributed-memory environments. The incarnations of the aforementioned parallelism are multi-threading, multi-processing and cluster-wide executions. In the area of multi-threading, we discuss the new implicit parallelism and related interfaces, as well as the new building blocks to safely operate with ROOT objects in a multi-threaded environment. Regarding multi-processing, we review the new MultiProc framework, comparing it with similar tools (e.g. multiprocessing module inmore » Python). Finally, as an alternative to PROOF for cluster-wide executions, we introduce the efforts on integrating ROOT with state-of-the-art distributed data processing technologies like Spark, both in terms of programming model and runtime design (with EOS as one of the main components). For all the levels of parallelism, we discuss, based on real-life examples and measurements, how our proposals can increase the productivity of scientists.« less

Dynamic Primitives of Motor Behavior

PubMed Central

Hogan, Neville; Sternad, Dagmar

2013-01-01

We present in outline a theory of sensorimotor control based on dynamic primitives, which we define as attractors. To account for the broad class of human interactive behaviors—especially tool use—we propose three distinct primitives: submovements, oscillations and mechanical impedances, the latter necessary for interaction with objects. Due to fundamental features of the neuromuscular system, most notably its slow response, we argue that encoding in terms of parameterized primitives may be an essential simplification required for learning, performance, and retention of complex skills. Primitives may simultaneously and sequentially be combined to produce observable forces and motions. This may be achieved by defining a virtual trajectory composed of submovements and/or oscillations interacting with impedances. Identifying primitives requires care: in principle, overlapping submovements would be sufficient to compose all observed movements but biological evidence shows that oscillations are a distinct primitive. Conversely, we suggest that kinematic synergies, frequently discussed as primitives of complex actions, may be an emergent consequence of neuromuscular impedance. To illustrate how these dynamic primitives may account for complex actions, we briefly review three types of interactive behaviors: constrained motion, impact tasks, and manipulation of dynamic objects. PMID:23124919

Mineral resource of the month: Pumice and pumicite

USGS Publications Warehouse

Crangle, Robert

2015-01-01

Pumice is an extrusive igneous volcanic rock formed through the rapid cooling of air-pocketed lava, which results in a low-density, high-porosity rock. Fine-grained pumice, or pumicite, is defined as minute grains, flakes, threads or shards of volcanic glass, with a size finer than 4 millimeters. 

Volatile and light lithophile elements in high-anorthite plagioclase-hosted melt inclusions from Iceland

NASA Astrophysics Data System (ADS)

Neave, David A.; Hartley, Margaret E.; Maclennan, John; Edmonds, Marie; Thordarson, Thorvaldur

2017-05-01

Melt inclusions formed during the early stages of magmatic evolution trap primitive melt compositions and enable the volatile contents of primary melts and the mantle to be estimated. However, the syn- and post-entrapment behaviour of volatiles in primitive high-anorthite plagioclase-hosted melt inclusions from oceanic basalts remains poorly constrained. To address this deficit, we present volatile and light lithophile element analyses from a well-characterised suite of nine matrix glasses and 102 melt inclusions from the 10 ka Grímsvötn tephra series (i.e., Saksunarvatn ash) of Iceland's Eastern Volcanic Zone (EVZ). High matrix glass H2O and S contents indicate that eruption-related exsolution was arrested by quenching in a phreatomagmatic setting; Li, B, F and Cl did not exsolve during eruption. The almost uniformly low CO2 content of plagioclase-hosted melt inclusions cannot be explained by either shallow entrapment or the sequestration of CO2 into shrinkage bubbles, suggesting that inclusion CO2 contents were controlled by decrepitation instead. High H2O/Ce values in primitive plagioclase-hosted inclusions (182-823) generally exceed values expected for EVZ primary melts (∼ 180), and can be accounted for by diffusive H2O gain following the entrainment of primitive macrocrysts into evolved and H2O-rich melts a few days before eruption. A strong positive correlation between H2O and Li in plagioclase-hosted inclusions suggests that diffusive Li gain may also have occurred. Extreme F enrichments in primitive plagioclase-hosted inclusions (F/Nd = 51-216 versus ∼15 in matrix glasses) possibly reflect the entrapment of inclusions from high-Al/(Al + Si) melt pools formed by dissolution-crystallisation processes (as indicated by HFSE depletions in some inclusions), and into which F was concentrated by uphill diffusion since F is highly soluble in Al-rich melts. The high S/Dy of primitive inclusions (∼300) indicates that primary melts were S-rich in comparison with most oceanic basalts. Cl and B are unfractionated from similarly compatible trace elements, and preserve records of primary melt heterogeneity. Although primitive plagioclase-hosted melt inclusions from the 10 ka Grímsvötn tephra series record few primary signals in their volatile contents, they nevertheless record information about crustal magma processing that is not captured in olivine-hosted melt inclusions suites.

Inchworm movement of two rings switching onto a thread by biased Brownian diffusion represent a three-body problem.

PubMed

Benson, Christopher R; Maffeo, Christopher; Fatila, Elisabeth M; Liu, Yun; Sheetz, Edward G; Aksimentiev, Aleksei; Singharoy, Abhishek; Flood, Amar H

2018-05-07

The coordinated motion of many individual components underpins the operation of all machines. However, despite generations of experience in engineering, understanding the motion of three or more coupled components remains a challenge, known since the time of Newton as the "three-body problem." Here, we describe, quantify, and simulate a molecular three-body problem of threading two molecular rings onto a linear molecular thread. Specifically, we use voltage-triggered reduction of a tetrazine-based thread to capture two cyanostar macrocycles and form a [3]pseudorotaxane product. As a consequence of the noncovalent coupling between the cyanostar rings, we find the threading occurs by an unexpected and rare inchworm-like motion where one ring follows the other. The mechanism was derived from controls, analysis of cyclic voltammetry (CV) traces, and Brownian dynamics simulations. CVs from two noncovalently interacting rings match that of two covalently linked rings designed to thread via the inchworm pathway, and they deviate considerably from the CV of a macrocycle designed to thread via a stepwise pathway. Time-dependent electrochemistry provides estimates of rate constants for threading. Experimentally derived parameters (energy wells, barriers, diffusion coefficients) helped determine likely pathways of motion with rate-kinetics and Brownian dynamics simulations. Simulations verified intercomponent coupling could be separated into ring-thread interactions for kinetics, and ring-ring interactions for thermodynamics to reduce the three-body problem to a two-body one. Our findings provide a basis for high-throughput design of molecular machinery with multiple components undergoing coupled motion.

Effect of threading defects on InGaN /GaN multiple quantum well light emitting diodes

NASA Astrophysics Data System (ADS)

Ferdous, M. S.; Wang, X.; Fairchild, M. N.; Hersee, S. D.

2007-12-01

Photoelectrochemical etching was used to measure the threading defect (TD) density in InGaN multiple quantum well light-emitting diodes (LEDs) fabricated from commercial quality epitaxial wafers. The TD density was measured in the LED active region and then correlated with the previously measured characteristics of these LEDs. It was found that the reverse leakage current increased exponentially with TD density. The temperature dependence of this dislocation-related leakage current was consistent with a hopping mechanism at low reverse-bias voltage and Poole-Frenkel emission at higher reverse-bias voltage. The peak intensity and spectral width of the LED electroluminescence were found to be only weakly dependent on TD density for the measured TD range of 1×107-2×108cm-2.

Red Thread Found on Bermuda Grass

Treesearch

T. H. Filer

1966-01-01

Red thread fungus (Corticium fuciforme (Berk.) Wakef.) was observed in 1965 and 1966 on Bermuda grass (Cynodon dactylon) on lawns in Leland, Mississippi. Red thread is a serious disease on fescues but has not previously been reported on Bermuda grass.

Turbulent dispersion of slightly buoyant oil droplets and turbulent breakup of crude oil droplets mixed with dispersants

NASA Astrophysics Data System (ADS)

Gopalan, Balaji

In part I, high speed in-line digital holographic cinematography is used for studying turbulent diffusion of slightly buoyant 0.5-1.2 mm diameter diesel droplets (specific gravity of 0.85) and 50 mum diameter neutral density particles. Experiments are performed in a 50x50x70 mm3 sample volume in a controlled, nearly isotropic turbulence facility, which is characterized by 2-D PIV. An automated tracking program has been used for measuring velocity time history of more than 17000 droplets and 15000 particles. The PDF's of droplet velocity fluctuations are close to Gaussian for all turbulent intensities ( u'i ). The mean rise velocity of droplets is enhanced or suppressed, compared to quiescent rise velocity (Uq), depending on Stokes number at lower turbulence levels, but becomes unconditionally enhanced at higher turbulence levels. The horizontal droplet velocity rms exceeds the fluid velocity rms for most of the data, while the vertical ones are higher than the fluid only at the highest turbulence level. The scaled droplet horizontal diffusion coefficient is higher than the vertical one, for 1 < u'i /Uq < 5, consistent with trends of the droplet velocity fluctuations. Conversely, the scaled droplet horizontal diffusion timescale is smaller than the vertical one due to crossing trajectories effect. The droplet diffusion coefficients scaled by the product of turbulence intensity and an integral length scale is a monotonically increasing function of u'i /Uq. Part II of this work explains the formation of micron sized droplets in turbulent flows from crude oil droplets pre-mixed with dispersants. Experimental visualization shows that this breakup starts with the formation of very long and quite stable, single or multiple micro threads that trail behind millimeter sized droplets. These threads form in regions with localized increase in concentration of surfactant, which in turn depends on the flow around the droplet. The resulting reduction of local surface tension, aided by high oil viscosity and stretching by the flow, suppresses capillary breakup and explains the stability of these threads. Due to increasing surface area and diffusion of dispersants into the continuous phase, the threads eventually breakup into ˜3 mum droplets.

Impact of oral vitamin D supplementation on the ocular surface in people with dry eye and/or low serum vitamin D.

PubMed

Yang, Chih-Huang; Albietz, Julie; Harkin, Damien G; Kimlin, Michael G; Schmid, Katrina L

2018-02-01

To determine the possible association between serum vitamin D levels and dry eye symptoms, and the impact of an oral vitamin D supplement. Three linked studies were performed. (i) 29 older adult participants, (ii) 29 dry eyed participants, and (iii) 2-month vitamin D supplementation for 32 dry eyed/low serum vitamin D levelled participants. All participants were assessed by the Ocular Surface Diseases Index (OSDI) to determine dry eye symptoms, and the phenol red thread test (PRT) and/or Schirmer's tear test, tear meniscus height, non-invasive tear break up time, grading ocular surface redness and fluorescein staining of the cornea to detect the tear quality and ocular surface conditions. Blood samples were collected for serum vitamin D analysis and interleukin-6 (IL-6) levels. Among older adult participants, vitamin D levels were negatively correlated with dry eye symptoms, the severity of dry eye, and associated with tired eye symptom. Vitamin D levels of people with dry eye diagnosis were not correlated with OSDI scores and IL-6 levels; while IL-6 levels showed correlation with tear production. In supplement study, vitamin D levels increased by 29mol/l, while dry eye symptoms and grading of corneal staining appeared significant reductions. No significant changes in IL-6 levels. Low vitamin D levels (<50nmol/l) were associated with dry eye symptoms in older individuals but not those diagnosed with dry eye. Vitamin D supplement increased the vitamin D levels, and improved dry eye symptoms, the tear quality and ocular surface conditions. Copyright © 2017 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

Supporting shared data structures on distributed memory architectures

NASA Technical Reports Server (NTRS)

Koelbel, Charles; Mehrotra, Piyush; Vanrosendale, John

1990-01-01

Programming nonshared memory systems is more difficult than programming shared memory systems, since there is no support for shared data structures. Current programming languages for distributed memory architectures force the user to decompose all data structures into separate pieces, with each piece owned by one of the processors in the machine, and with all communication explicitly specified by low-level message-passing primitives. A new programming environment is presented for distributed memory architectures, providing a global name space and allowing direct access to remote parts of data values. The analysis and program transformations required to implement this environment are described, and the efficiency of the resulting code on the NCUBE/7 and IPSC/2 hypercubes are described.

Using the CMS threaded framework in a production environment

DOE PAGES

Jones, C. D.; Contreras, L.; Gartung, P.; ...

2015-12-23

During 2014, the CMS Offline and Computing Organization completed the necessary changes to use the CMS threaded framework in the full production environment. We will briefly discuss the design of the CMS Threaded Framework, in particular how the design affects scaling performance. We will then cover the effort involved in getting both the CMSSW application software and the workflow management system ready for using multiple threads for production. Finally, we will present metrics on the performance of the application and workflow system as well as the difficulties which were uncovered. As a result, we will end with CMS' plans formore » using the threaded framework to do production for LHC Run 2.« less

Conceptual Design Study on Bolts for Self-Loosing Preventable Threaded Fasteners

NASA Astrophysics Data System (ADS)

Noma, Atsushi; He, Jianmei

2017-11-01

Threaded fasteners using bolts is widely applied in industrial field as well as various fields. However, threaded fasteners using bolts have loosing problems and cause many accidents. In this study, the purpose is to obtain self-loosing preventable threaded fasteners by applying spring characteristic effects on bolt structures. Helical-cutting applied bolt structures is introduced through three dimensional (3D) CAD modeling tools. Analytical approaches for evaluations on the spring characteristic effects helical-cutting applied bolt structures and self-loosing preventable performance of threaded fasteners were performed using finite element method and results are reported. Comparing slackness test results with analytical results and more details on evaluating mechanical properties will be executed in future study.

Incremental Drag due to Grooves and Threads for KE (Kinetic Energy) Projectiles

DTIC Science & Technology

1989-03-01

RFI • CTsB TF * - MF (3a) q L where TF1 is the Thread Factor defined as: TF 0.84 + 0.117 P - o (3b) where p is the groove pitch in inches, MF1 is...g2) MF RF CD (4) where TF11 and TF1 2 are the thread factors for the threads of pitch p, and P2, respectively. 5 One can notice the large

Evaluating the use of laser radiation in cleaning of copper embroidery threads on archaeological Egyptian textiles

NASA Astrophysics Data System (ADS)

Abdel-Kareem, Omar; Harith, M. A.

2008-07-01

Cleaning of copper embroidery threads on archaeological textiles is still a complicated conservation process, as most textile conservators believe that the advantages of using traditional cleaning techniques are less than their disadvantages. In this study, the uses of laser cleaning method and two modified recipes of wet cleaning methods were evaluated for cleaning of the corroded archaeological Egyptian copper embroidery threads on an archaeological Egyptian textile fabric. Some corroded copper thread samples were cleaned using modified recipes of wet cleaning method; other corroded copper thread samples were cleaned with Q-switched Nd:YAG laser radiation of wavelength 532 nm. All tested metal thread samples before and after cleaning were investigated using a light microscope and a scanning electron microscope with an energy dispersive X-ray analysis unit. Also the laser-induced breakdown spectroscopy (LIBS) technique was used for the elemental analysis of laser-cleaned samples to follow up the laser cleaning procedure. The results show that laser cleaning is the most effective method among all tested methods in the cleaning of corroded copper threads. It can be used safely in removing the corrosion products without any damage to both metal strips and fibrous core. The tested laser cleaning technique has solved the problems caused by other traditional cleaning techniques that are commonly used in the cleaning of metal threads on museum textiles.

Application Of Laser Induced Breakdown Spectroscopy (LIBS) Technique In Investigation Of Historical Metal Threads

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abdel-Kareem, O.; Khedr, A.; Abdelhamid, M.

Analysis of the composition of an object is a necessary step in the documentation of the properties of this object for estimating its condition. Also this is an important task for establishing an appropriate conservation treatment of an object or to follow up the result of the application of the suggested treatments. There has been an important evolution in the methods used for analysis of metal threads since the second half of the twentieth century. Today, the main considerations of selecting a method are based on the diagnostic power, representative sampling, reproducibility, destructive nature/invasiveness of analysis and accessibility to themore » appropriate instrument. This study aims at evaluating the usefulness of the use of Laser Induced Breakdown Spectroscopy (LIBS) Technique for analysis of historical metal threads. In this study various historical metal threads collected from different museums were investigated using (LIBS) technique. For evaluating usefulness of the suggested analytical protocol of this technique, the same investigated metal thread samples were investigated with Scanning Electron Microscope (SEM) with energy-dispersive x-ray analyzer (EDX) which is reported in conservation field as the best method, to determine the chemical composition, and corrosion of investigated metal threads. The results show that all investigated metal threads in the present study are too dirty, strongly damaged and corroded with different types of corrosion products. Laser Induced Breakdown Spectroscopy (LIBS) Technique is considered very useful technique that can be used safely for investigating historical metal threads. It is, in fact, very useful tool as a noninvasive method for analysis of historical metal threads. The first few laser shots are very useful for the investigation of the corrosion and dirt layer, while the following shots are very useful and effective for investigating the coating layer. Higher number of laser shots are very useful for the main composition of the metal thread. There is a necessity to carry out further research to investigate and determine the most appropriate and effective approaches and methods for conservation of these metal threads.« less

Histomorphometric Evaluation of the Effects of Various Diode Lasers and Force Levels on Orthodontic Mini Screw Stability

PubMed Central

Isman, Eren; Taner, Lale; Kurkcu, Mehmet

2015-01-01

Abstract Objective The purpose of this study was to evaluate the effects of different laser dose and force levels on the stability of orthodontic mini screws used for anchorage, by histomorphometric analyses. Background data Low-level laser therapy speeds up blood flow, improves the mechanism of the revitalization processes, reduces the risk of infection, boosts metabolic activities, and accelerates the healing of the damaged tissue. Although there are many research studies about low-level laser therapy applications in a variety of areas, no investigations were found concerning mini screw stability using various laser dose levels with different force level applications. Methods Seventeen New Zealand white rabbits were used. A total of 68 cylindrical, self-drilling orthodontic mini screws were threaded at the fibula. Experimental subjects were divided into six groups; force application was not performed in the first three groups, whereas 150g of force was applied via nickel-titanium closed-coil springs placed between two mini screws in the other three groups. Measurements of the initial torque values (10 Ncm) were manipulated by a digital portable torque gauge. Various low-level laser doses were applied to the groups during the postoperative 10 days. After 4 weeks, bone-to-implant contact and cortical bone thickness were histomorphometrically analyzed. Results In the 150g force plus 20 J/cm2 dosage group, the highest bone-to-implant contact values were observed. (p<0.05) There were no statistically significant correlations between cortical bone thickness and bone-to-implant contact values; on the other hand, no significant difference was found among the same groups in terms of cortical bone thickness values (p>0.05). Conclusions Low-level laser therapy was noticed to induce the mini screw–bone contact area. Low-level laser therapy may be a supplementary treatment method to increase the stability of the orthodontic mini screw. PMID:25594769

Comparison of resin film infusion, resin transfer molding, and consolidation of textile preforms for primary aircraft structure

NASA Technical Reports Server (NTRS)

Suarez, J.; Dastin, S.

1992-01-01

Under NASA's Novel Composites for Wing and Fuselage Applications (NCWFA) Program, Grumman is developing innovative design concepts and cost-effective fabrication processes for damage-tolerant primary structures that can perform at a design ultimate strain level of 6000 micro-inch/inch. Attention has focused on the use of textile high-performance fiber-reinforcement concepts that provide improved damage tolerance and out-of-plane load capability, low-cost resin film infusion (RFI) and resin transfer molding (RTM) processes, and thermoplastic forming concepts. The fabrication of wing 'Y' spars by four different materials/processes methods is described: 'Y' spars fabricated using IM7 angle interlock 0/90 deg woven preforms with +/- 45 deg plies stitched with Toray high-strength graphite thread and processed using RFI and 3501-6 epoxy; 'Y' spars fabricated using G40-800 knitted/stitched preforms and processed using RFI and 3501-6 epoxy; 'Y' spars fabricated using G40-800 knitted/stitched preforms and processed using RTM and Tactix 123/H41 epoxy; and 'Y' spars fabricated using AS4(6k)/PEEK 150-g commingled angle interlock 0/90 deg woven preforms with +/- 45 deg commingled plies stitched using high-strength graphite thread and processed by consolidation. A comparison of the structural efficiency, processability, and projected acquisition cost of these representative spars is presented.

Real-time SHVC software decoding with multi-threaded parallel processing

NASA Astrophysics Data System (ADS)

Gudumasu, Srinivas; He, Yuwen; Ye, Yan; He, Yong; Ryu, Eun-Seok; Dong, Jie; Xiu, Xiaoyu

2014-09-01

This paper proposes a parallel decoding framework for scalable HEVC (SHVC). Various optimization technologies are implemented on the basis of SHVC reference software SHM-2.0 to achieve real-time decoding speed for the two layer spatial scalability configuration. SHVC decoder complexity is analyzed with profiling information. The decoding process at each layer and the up-sampling process are designed in parallel and scheduled by a high level application task manager. Within each layer, multi-threaded decoding is applied to accelerate the layer decoding speed. Entropy decoding, reconstruction, and in-loop processing are pipeline designed with multiple threads based on groups of coding tree units (CTU). A group of CTUs is treated as a processing unit in each pipeline stage to achieve a better trade-off between parallelism and synchronization. Motion compensation, inverse quantization, and inverse transform modules are further optimized with SSE4 SIMD instructions. Simulations on a desktop with an Intel i7 processor 2600 running at 3.4 GHz show that the parallel SHVC software decoder is able to decode 1080p spatial 2x at up to 60 fps (frames per second) and 1080p spatial 1.5x at up to 50 fps for those bitstreams generated with SHVC common test conditions in the JCT-VC standardization group. The decoding performance at various bitrates with different optimization technologies and different numbers of threads are compared in terms of decoding speed and resource usage, including processor and memory.

Adhesion enhancement of cribellate capture threads by epicuticular waxes of the insect prey sheds new light on spider web evolution

PubMed Central

Bott, Raya A.; Bräunig, Peter

2017-01-01

To survive, web-building spiders rely on their capture threads to restrain prey. Many species use special adhesives for this task, and again the majority of those species cover their threads with viscoelastic glue droplets. Cribellate spiders, by contrast, use a wool of nanofibres as adhesive. Previous studies hypothesized that prey is restrained by van der Waals' forces and entrapment in the nanofibres. A large discrepancy when comparing the adhesive force on artificial surfaces versus prey implied that the real mechanism was still elusive. We observed that insect prey's epicuticular waxes infiltrate the wool of nanofibres, probably induced by capillary forces. The fibre-reinforced composite thus formed led to an adhesion between prey and thread eight times stronger than that between thread and wax-free surfaces. Thus, cribellate spiders employ the originally protective coating of their insect prey as a fatal component of their adhesive and the insect promotes its own capture. We suggest an evolutionary arms race with prey changing the properties of their cuticular waxes to escape the cribellate capture threads that eventually favoured spider threads with viscous glue. PMID:28566485

Attenuation of the tip vortex flow using a flexible thread

NASA Astrophysics Data System (ADS)

Lee, Seung-Jae; Shin, Jin-Woo; Arndt, Roger E. A.; Suh, Jung-Chun

2018-01-01

Tip vortex cavitation (TVC) is important in a number of practical engineering applications. The onset of TVC is a critical concern for navy surface ships and submarines that aim to increase their capability to evade detection. A flexible thread attachment at blade tips was recently suggested as a new method to delay the onset of TVC. Although the occurrence of TVC can be reduced using a flexible thread, no scientific investigation focusing on its mechanisms has been undertaken. Thus, herein, we experimentally investigated the use of the flexible thread to suppress TVC from an elliptical wing. These investigations were performed in a cavitation tunnel and involved an observation of TVC using high-speed cameras, motion tracking of the thread using image-processing techniques, and near-field flow measurements performed using stereoscopic particle image velocimetry. The experimental data suggested that the flexible thread affects the axial velocity field more than the circumferential velocity field around the TVC axis. Furthermore, we observed no clear dependence of the vortex core size, circulation, and flow unsteadiness on TVC suppression. However, the presence of the thread at the wing tip led to a notable reduction in the streamwise velocity field, thereby alleviating TVC.

Collagen insulated from tensile damage by domains that unfold reversibly: in situ X-ray investigation of mechanical yield and damage repair in the mussel byssus

PubMed Central

Harrington, Matthew J.; Gupta, Himadri S.; Fratzl, Peter; Waite, J. Herbert

2009-01-01

The byssal threads of the California mussel, Mytilus californianus, are highly hysteretic, elastomeric fibers that collectively perform a holdfast function in wave-swept rocky seashore habitats. Following cyclic loading past the mechanical yield point, threads exhibit a damage-dependent reduction in mechanical performance. However, the distal portion of the byssal thread is capable of recovering initial material properties through a time-dependent healing process in the absence of active cellular metabolism. Byssal threads are composed almost exclusively of multi-domain hybrid collagens known as preCols, which largely determine the mechanical properties of the thread. Here, the structure-property relationships that govern thread mechanical performance are further probed. The molecular rearrangements that occur during yield and damage repair were investigated using time-resolved in situ wide angle X-ray diffraction (WAXD) coupled with cyclic tensile loading of threads and through thermally enhanced damage-repair studies. Results indicate that the collagen domains in byssal preCols are mechanically protected by the unfolding of sacrificial non-collagenous domains that refold on a slower time-scale. Time-dependent healing is primarily attributed to stochastic recoupling of broken histidine-metal coordination complexes. PMID:19275941

Thread concept for automatic task parallelization in image analysis

NASA Astrophysics Data System (ADS)

Lueckenhaus, Maximilian; Eckstein, Wolfgang

1998-09-01

Parallel processing of image analysis tasks is an essential method to speed up image processing and helps to exploit the full capacity of distributed systems. However, writing parallel code is a difficult and time-consuming process and often leads to an architecture-dependent program that has to be re-implemented when changing the hardware. Therefore it is highly desirable to do the parallelization automatically. For this we have developed a special kind of thread concept for image analysis tasks. Threads derivated from one subtask may share objects and run in the same context but may process different threads of execution and work on different data in parallel. In this paper we describe the basics of our thread concept and show how it can be used as basis of an automatic task parallelization to speed up image processing. We further illustrate the design and implementation of an agent-based system that uses image analysis threads for generating and processing parallel programs by taking into account the available hardware. The tests made with our system prototype show that the thread concept combined with the agent paradigm is suitable to speed up image processing by an automatic parallelization of image analysis tasks.

29 CFR 1910.103 - Hydrogen.

Code of Federal Regulations, 2013 CFR

2013-07-01

..., threaded, socket, or compression fittings. Gaskets and thread sealants shall be suitable for hydrogen... closures. (v) Piping, tubing, and fittings. (a) Piping, tubing, and fittings and gasket and thread sealants... including process or analytical equipment. (c) Be located 25 feet from concentrations of people. (d) Be...

Automated quality control for stitching of textile articles

NASA Technical Reports Server (NTRS)

Miller, Jeffrey L. (Inventor); Markus, Alan (Inventor)

1999-01-01

Quality control for stitching of a textile article is performed by measuring thread tension in the stitches as the stitches are being made, determining locations of the stitches, and generating a map including the locations and stitching data derived from the measured thread tensions. The stitching data can be analyzed, off-line or in real time, to identify defective stitches. Defective stitches can then be repaired. Real time analysis of the thread tensions allows problems such as broken needle threads to be corrected immediately.

THE THERMAL INSTABILITY OF SOLAR PROMINENCE THREADS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Soler, R.; Goossens, M.; Ballester, J. L., E-mail: roberto.soler@wis.kuleuven.be

The fine structure of solar prominences and filaments appears as thin and long threads in high-resolution images. In H{alpha} observations of filaments, some threads can be observed for only 5-20 minutes before they seem to fade and eventually disappear, suggesting that these threads may have very short lifetimes. The presence of an instability might be the cause of this quick disappearance. Here, we study the thermal instability of prominence threads as an explanation of their sudden disappearance from H{alpha} observations. We model a prominence thread as a magnetic tube with prominence conditions embedded in a coronal environment. We assume amore » variation of the physical properties in the transverse direction so that the temperature and density continuously change from internal to external values in an inhomogeneous transitional layer representing the particular prominence-corona transition region (PCTR) of the thread. We use the nonadiabatic and resistive magnetohydrodynamic equations, which include terms due to thermal conduction parallel and perpendicular to the magnetic field, radiative losses, heating, and magnetic diffusion. We combine both analytical and numerical methods to study linear perturbations from the equilibrium state, focusing on unstable thermal solutions. We find that thermal modes are unstable in the PCTR for temperatures higher than 80,000 K, approximately. These modes are related to temperature disturbances that can lead to changes in the equilibrium due to rapid plasma heating or cooling. For typical prominence parameters, the instability timescale is of the order of a few minutes and is independent of the form of the temperature profile within the PCTR of the thread. This result indicates that thermal instability may play an important role for the short lifetimes of threads in the observations.« less

Genetic algorithms for protein threading.

PubMed

Yadgari, J; Amir, A; Unger, R

1998-01-01

Despite many years of efforts, a direct prediction of protein structure from sequence is still not possible. As a result, in the last few years researchers have started to address the "inverse folding problem": Identifying and aligning a sequence to the fold with which it is most compatible, a process known as "threading". In two meetings in which protein folding predictions were objectively evaluated, it became clear that threading as a concept promises a real breakthrough, but that much improvement is still needed in the technique itself. Threading is a NP-hard problem, and thus no general polynomial solution can be expected. Still a practical approach with demonstrated ability to find optimal solutions in many cases, and acceptable solutions in other cases, is needed. We applied the technique of Genetic Algorithms in order to significantly improve the ability of threading algorithms to find the optimal alignment of a sequence to a structure, i.e. the alignment with the minimum free energy. A major progress reported here is the design of a representation of the threading alignment as a string of fixed length. With this representation validation of alignments and genetic operators are effectively implemented. Appropriate data structure and parameters have been selected. It is shown that Genetic Algorithm threading is effective and is able to find the optimal alignment in a few test cases. Furthermore, the described algorithm is shown to perform well even without pre-definition of core elements. Existing threading methods are dependent on such constraints to make their calculations feasible. But the concept of core elements is inherently arbitrary and should be avoided if possible. While a rigorous proof is hard to submit yet an, we present indications that indeed Genetic Algorithm threading is capable of finding consistently good solutions of full alignments in search spaces of size up to 10(70).

DOE Office of Scientific and Technical Information (OSTI.GOV)

Attinella, John E.; Davis, Kristan D.; Musselman, Roy G.

Methods, apparatuses, and computer program products for servicing a globally broadcast interrupt signal in a multi-threaded computer comprising a plurality of processor threads. Embodiments include an interrupt controller indicating in a plurality of local interrupt status locations that a globally broadcast interrupt signal has been received by the interrupt controller. Embodiments also include a thread determining that a local interrupt status location corresponding to the thread indicates that the globally broadcast interrupt signal has been received by the interrupt controller. Embodiments also include the thread processing one or more entries in a global interrupt status bit queue based on whethermore » global interrupt status bits associated with the globally broadcast interrupt signal are locked. Each entry in the global interrupt status bit queue corresponds to a queued global interrupt.« less

A musculoskeletal model of human locomotion driven by a low dimensional set of impulsive excitation primitives

PubMed Central

Sartori, Massimo; Gizzi, Leonardo; Lloyd, David G.; Farina, Dario

2013-01-01

Human locomotion has been described as being generated by an impulsive (burst-like) excitation of groups of musculotendon units, with timing dependent on the biomechanical goal of the task. Despite this view being supported by many experimental observations on specific locomotion tasks, it is still unknown if the same impulsive controller (i.e., a low-dimensional set of time-delayed excitastion primitives) can be used as input drive for large musculoskeletal models across different human locomotion tasks. For this purpose, we extracted, with non-negative matrix factorization, five non-negative factors from a large sample of muscle electromyograms in two healthy subjects during four motor tasks. These included walking, running, sidestepping, and crossover cutting maneuvers. The extracted non-negative factors were then averaged and parameterized to obtain task-generic Gaussian-shaped impulsive excitation curves or primitives. These were used to drive a subject-specific musculoskeletal model of the human lower extremity. Results showed that the same set of five impulsive excitation primitives could be used to predict the dynamics of 34 musculotendon units and the resulting hip, knee and ankle joint moments (i.e., NRMSE = 0.18 ± 0.08, and R2 = 0.73 ± 0.22 across all tasks and subjects) without substantial loss of accuracy with respect to using experimental electromyograms (i.e., NRMSE = 0.16 ± 0.07, and R2 = 0.78 ± 0.18 across all tasks and subjects). Results support the hypothesis that biomechanically different motor tasks might share similar neuromuscular control strategies. This might have implications in neurorehabilitation technologies such as human-machine interfaces for the torque-driven, proportional control of powered prostheses and orthoses. In this, device control commands (i.e., predicted joint torque) could be derived without direct experimental data but relying on simple parameterized Gaussian-shaped curves, thus decreasing the input drive complexity and the number of needed sensors. PMID:23805099

A musculoskeletal model of human locomotion driven by a low dimensional set of impulsive excitation primitives.

PubMed

Sartori, Massimo; Gizzi, Leonardo; Lloyd, David G; Farina, Dario

2013-01-01

Human locomotion has been described as being generated by an impulsive (burst-like) excitation of groups of musculotendon units, with timing dependent on the biomechanical goal of the task. Despite this view being supported by many experimental observations on specific locomotion tasks, it is still unknown if the same impulsive controller (i.e., a low-dimensional set of time-delayed excitastion primitives) can be used as input drive for large musculoskeletal models across different human locomotion tasks. For this purpose, we extracted, with non-negative matrix factorization, five non-negative factors from a large sample of muscle electromyograms in two healthy subjects during four motor tasks. These included walking, running, sidestepping, and crossover cutting maneuvers. The extracted non-negative factors were then averaged and parameterized to obtain task-generic Gaussian-shaped impulsive excitation curves or primitives. These were used to drive a subject-specific musculoskeletal model of the human lower extremity. Results showed that the same set of five impulsive excitation primitives could be used to predict the dynamics of 34 musculotendon units and the resulting hip, knee and ankle joint moments (i.e., NRMSE = 0.18 ± 0.08, and R (2) = 0.73 ± 0.22 across all tasks and subjects) without substantial loss of accuracy with respect to using experimental electromyograms (i.e., NRMSE = 0.16 ± 0.07, and R (2) = 0.78 ± 0.18 across all tasks and subjects). Results support the hypothesis that biomechanically different motor tasks might share similar neuromuscular control strategies. This might have implications in neurorehabilitation technologies such as human-machine interfaces for the torque-driven, proportional control of powered prostheses and orthoses. In this, device control commands (i.e., predicted joint torque) could be derived without direct experimental data but relying on simple parameterized Gaussian-shaped curves, thus decreasing the input drive complexity and the number of needed sensors.

Speech perception at the interface of neurobiology and linguistics.

PubMed

Poeppel, David; Idsardi, William J; van Wassenhove, Virginie

2008-03-12

Speech perception consists of a set of computations that take continuously varying acoustic waveforms as input and generate discrete representations that make contact with the lexical representations stored in long-term memory as output. Because the perceptual objects that are recognized by the speech perception enter into subsequent linguistic computation, the format that is used for lexical representation and processing fundamentally constrains the speech perceptual processes. Consequently, theories of speech perception must, at some level, be tightly linked to theories of lexical representation. Minimally, speech perception must yield representations that smoothly and rapidly interface with stored lexical items. Adopting the perspective of Marr, we argue and provide neurobiological and psychophysical evidence for the following research programme. First, at the implementational level, speech perception is a multi-time resolution process, with perceptual analyses occurring concurrently on at least two time scales (approx. 20-80 ms, approx. 150-300 ms), commensurate with (sub)segmental and syllabic analyses, respectively. Second, at the algorithmic level, we suggest that perception proceeds on the basis of internal forward models, or uses an 'analysis-by-synthesis' approach. Third, at the computational level (in the sense of Marr), the theory of lexical representation that we adopt is principally informed by phonological research and assumes that words are represented in the mental lexicon in terms of sequences of discrete segments composed of distinctive features. One important goal of the research programme is to develop linking hypotheses between putative neurobiological primitives (e.g. temporal primitives) and those primitives derived from linguistic inquiry, to arrive ultimately at a biologically sensible and theoretically satisfying model of representation and computation in speech.

Navigation Strategies for Primitive Solar System Body Rendezvous and Proximity Operations

NASA Technical Reports Server (NTRS)

Getzandanner, Kenneth M.

2011-01-01

A wealth of scientific knowledge regarding the composition and evolution of the solar system can be gained through reconnaissance missions to primitive solar system bodies. This paper presents analysis of a baseline navigation strategy designed to address the unique challenges of primitive body navigation. Linear covariance and Monte Carlo error analysis was performed on a baseline navigation strategy using simulated data from a· design reference mission (DRM). The objective of the DRM is to approach, rendezvous, and maintain a stable orbit about the near-Earth asteroid 4660 Nereus. The outlined navigation strategy and resulting analyses, however, are not necessarily limited to this specific target asteroid as they may he applicable to a diverse range of mission scenarios. The baseline navigation strategy included simulated data from Deep Space Network (DSN) radiometric tracking and optical image processing (OpNav). Results from the linear covariance and Monte Carlo analyses suggest the DRM navigation strategy is sufficient to approach and perform proximity operations in the vicinity of the target asteroid with meter-level accuracy.

Hierarchical HMM based learning of navigation primitives for cooperative robotic endovascular catheterization.

PubMed

Rafii-Tari, Hedyeh; Liu, Jindong; Payne, Christopher J; Bicknell, Colin; Yang, Guang-Zhong

2014-01-01

Despite increased use of remote-controlled steerable catheter navigation systems for endovascular intervention, most current designs are based on master configurations which tend to alter natural operator tool interactions. This introduces problems to both ergonomics and shared human-robot control. This paper proposes a novel cooperative robotic catheterization system based on learning-from-demonstration. By encoding the higher-level structure of a catheterization task as a sequence of primitive motions, we demonstrate how to achieve prospective learning for complex tasks whilst incorporating subject-specific variations. A hierarchical Hidden Markov Model is used to model each movement primitive as well as their sequential relationship. This model is applied to generation of motion sequences, recognition of operator input, and prediction of future movements for the robot. The framework is validated by comparing catheter tip motions against the manual approach, showing significant improvements in the quality of catheterization. The results motivate the design of collaborative robotic systems that are intuitive to use, while reducing the cognitive workload of the operator.

The mevalonate pathway regulates primitive streak formation via protein farnesylation

PubMed Central

Okamoto-Uchida, Yoshimi; Yu, Ruoxing; Miyamura, Norio; Arima, Norie; Ishigami-Yuasa, Mari; Kagechika, Hiroyuki; Yoshida, Suguru; Hosoya, Takamitsu; Nawa, Makiko; Kasama, Takeshi; Asaoka, Yoichi; Alois, Reiner Wimmer; Elling, Ulrich; Penninger, Josef M.; Nishina, Sachiko; Azuma, Noriyuki; Nishina, Hiroshi

2016-01-01

The primitive streak in peri-implantation embryos forms the mesoderm and endoderm and controls cell differentiation. The metabolic cues regulating primitive streak formation remain largely unknown. Here we utilised a mouse embryonic stem (ES) cell differentiation system and a library of well-characterised drugs to identify these metabolic factors. We found that statins, which inhibit the mevalonate metabolic pathway, suppressed primitive streak formation in vitro and in vivo. Using metabolomics and pharmacologic approaches we identified the downstream signalling pathway of mevalonate and revealed that primitive streak formation requires protein farnesylation but not cholesterol synthesis. A tagging-via-substrate approach revealed that nuclear lamin B1 and small G proteins were farnesylated in embryoid bodies and important for primitive streak gene expression. In conclusion, protein farnesylation driven by the mevalonate pathway is a metabolic cue essential for primitive streak formation. PMID:27883036

Threaded Discussion Instructional Strategies and Student Performance

ERIC Educational Resources Information Center

Krull, Rodger Pratt

2013-01-01

Educators need insight into what instructional strategies are effective in the online environment, but few researchers have contrasted threaded discussion strategies and measures of student performance using a quantitative approach. Also, the effectiveness of threaded discussion strategies across all student generation groups or between genders is…

Tensile Shear Properties of the Friction Stir Lap Welded Joints and Material Flow Mechanism Under Pulsatile Revolutions

NASA Astrophysics Data System (ADS)

Hu, Yanying; Liu, Huijie; Du, Shuaishuai

2018-06-01

The aim of the present article is to offer insight into the effects of pin profiles on interface defects, tensile shear properties, microstructures, and the material flow of friction stir lap welded joints. The results indicate that, compared to the lap joints welded by the single threaded plane pin, the three-plane threaded pin, and the triangle threaded pin, the lap joint obtained by the conventional conical threaded pin is characterized by the minimum interface defect. The alternate threads and planes on the pin provide periodical stress, leading to pulsatile material flow patterns. Under the effect of pulsatile revolutions, an asymmetrical flow field is formed around the tool. The threads on the pin force the surrounding material to flow downward. The planes cannot only promote the horizontal flow of the material by scraping, but also provide extra space for the material vertical flow. A heuristic model is established to describe the material flow mechanism during friction stir lap welding under the effect of pulsatile revolutions.

Mechanical Strength Improvements of Carbon Nanotube Threads through Epoxy Cross-Linking

PubMed Central

Yu, Qingyue; Alvarez, Noe T.; Miller, Peter; Malik, Rachit; Haase, Mark R.; Schulz, Mark; Shanov, Vesselin; Zhu, Xinbao

2016-01-01

Individual Carbon Nanotubes (CNTs) have a great mechanical strength that needs to be transferred into macroscopic fiber assemblies. One approach to improve the mechanical strength of the CNT assemblies is by creating covalent bonding among their individual CNT building blocks. Chemical cross-linking of multiwall CNTs (MWCNTs) within the fiber has significantly improved the strength of MWCNT thread. Results reported in this work show that the cross-linked thread had a tensile strength six times greater than the strength of its control counterpart, a pristine MWCNT thread (1192 MPa and 194 MPa, respectively). Additionally, electrical conductivity changes were observed, revealing 2123.40 S·cm−1 for cross-linked thread, and 3984.26 S·cm−1 for pristine CNT thread. Characterization suggests that the obtained high tensile strength is due to the cross-linking reaction of amine groups from ethylenediamine plasma-functionalized CNT with the epoxy groups of the cross-linking agent, 4,4-methylenebis(N,N-diglycidylaniline). PMID:28787868

Correlation between the sub-structure parameters and the manufacturing technologies of metal threads in historical textiles using X-ray line profile analysis

NASA Astrophysics Data System (ADS)

Csiszár, Gábor; Ungár, Tamás; Járó, Márta

2013-06-01

Micro-structure can talk when documentation is missing. In ancient Roman or medieval periods, kings, queens, or just rich people decorated their clothes or even their horse covers richly with miniature jewels or metal threads. The origin or the fabrication techniques of these ancient threads is often unknown. Thirteen thread samples made of gold or gilt silver manufactured during the last sixteen hundred years are investigated for the micro-structure in terms of dislocation density, crystallite size, and planar defects. In a few cases, these features are compared with sub-structure of similar metallic threads prepared in modern, twentieth century workshops. The sub-structure is determined by X-ray line profile analysis, using high resolution diffractograms with negligible instrumental broadening. On the basis of the sub-structure parameters, we attempt to assess the metal-threads manufacturing procedures on samples stemming from the fourth century A.D. until now.

Platform-Independence and Scheduling In a Multi-Threaded Real-Time Simulation

NASA Technical Reports Server (NTRS)

Sugden, Paul P.; Rau, Melissa A.; Kenney, P. Sean

2001-01-01

Aviation research often relies on real-time, pilot-in-the-loop flight simulation as a means to develop new flight software, flight hardware, or pilot procedures. Often these simulations become so complex that a single processor is incapable of performing the necessary computations within a fixed time-step. Threads are an elegant means to distribute the computational work-load when running on a symmetric multi-processor machine. However, programming with threads often requires operating system specific calls that reduce code portability and maintainability. While a multi-threaded simulation allows a significant increase in the simulation complexity, it also increases the workload of a simulation operator by requiring that the operator determine which models run on which thread. To address these concerns an object-oriented design was implemented in the NASA Langley Standard Real-Time Simulation in C++ (LaSRS++) application framework. The design provides a portable and maintainable means to use threads and also provides a mechanism to automatically load balance the simulation models.

Along-strike variability of primitive magmas (major and volatile elements) inferred from olivine-hosted melt inclusions, southernmost Andean Southern Volcanic Zone, Chile

NASA Astrophysics Data System (ADS)

Weller, D. J.; Stern, C. R.

2018-01-01

Glass compositions of melt inclusions in olivine phenocrysts found in tephras derived from explosive eruptions of the four volcanoes along the volcanic front of the southernmost Andean Southern Volcanic Zone (SSVZ) are used to constrain primitive magma compositions and melt generation parameters. Primitive magmas from Hudson, Macá, and Melimoyu have similar compositions and are formed by low degrees (8-18%) of partial melting. Compared to these other three centers, primitive magmas from Mentolat have higher Al2O3 and lower MgO, TiO2 and other incompatible minor elements, and are generated by somewhat higher degrees (12-20%) of partial melting. The differences in the estimated primitive parental magma compositions between Mentolat and the other three volcanic centers are consistent with difference in the more evolved magmas erupted from these centers, Mentolat magmas having higher Al2O3 and lower MgO, TiO2 and other incompatible minor element contents, suggesting that these differences are controlled by melting processes in the mantle source region above the subducted oceanic plate. Parental magma S = 1430-594 and Cl = 777-125 (μg/g) contents of Hudson, Macá, and Melimoyu are similar to other volcanoes further north in the SVZ. However, Mentolat primitive magmas have notably higher concentrations of S = 2656-1227 and Cl = 1078-704 (μg/g). The observed along-arc changes in parental magma chemistry may be due to the close proximity below Mentolat of the subducted Guamblin Fracture Zone that could efficiently transport hydrous mineral phases, seawater, and sediment into the mantle, driving enhanced volatile fluxed melting beneath this center compared to the others. Table S2. Olivine-hosted melt inclusion compositions, host-olivine compositions, and the post-entrapment crystallization corrected melt inclusion compositions. Table S3. Olivine-hosted melt inclusion modeling information. Table S4. Major element compositions of the fractionation corrected melt inclusion in equilibrium with mantle olivine. Table S5. Melting parameters Fm and CoH2O. Table S6. Major element compositions of phenocrysts and glasses occurring with the olivine-hosted melt inclusions.

On Ceramics.

ERIC Educational Resources Information Center

School Arts, 1982

1982-01-01

Presents four ceramics activities for secondary-level art classes. Included are directions for primitive kiln construction and glaze making. Two ceramics design activities are described in which students make bizarrely-shaped lidded jars, feet, and footwear. (AM)

Segmented instrumentation tube including a locking sleeve for interlocking the segments of the instrumentation tube

DOEpatents

Obermeyer, F.D.

1993-11-16

Segmented instrumentation tube including a locking sleeve for interlocking the segments of the instrumentation tube, so that the threaded ends of the instrumentation tube do not unthread when subjected to vibration, such an instrumentation tube being suitable for use in a nuclear reactor pressure vessel. The instrumentation tube has a first member having a threaded end portion that has a plurality of first holes circumferentially around the outside surface thereof. The instrumentation tube also has a second member having a threaded end portion that has a plurality of second holes circumferentially around the outside surface thereof. The threads of the second member are caused to threadably engage the threads of the first member for defining a threaded joint there between. A sleeve having an inside surface surrounds the end portion of the first member and the end portion of the second member and thus surrounds the threaded joint. The sleeve includes a plurality of first projections and second projections that outwardly extend from the inside surface to engage the first holes and the second holes, respectively. The outside surface of the sleeve is crimped or swaged at the locations of the first projections and second projections such that the first projections and the second projections engage their respective holes. In this manner, independent rotation of the first member with respect to the second member is prevented, so that the instrumentation tube will not unthread at its threaded joint. 10 figures.

Segmented instrumentation tube including a locking sleeve for interlocking the segments of the instrumentation tube

DOEpatents

Obermeyer, Franklin D.

1993-01-01

Segmented instrumentation tube including a locking sleeve for interlocking the segments of the instrumentation tube, so that the threaded ends of the instrumentation tube do not unthread when subjected to vibration, such an instrumentation tube being suitable for use in a nuclear reactor pressure vessel. The instrumentation tube has a first member having a threaded end portion that has a plurality of first holes circumferentially around the outside surface thereof. The instrumentation tube also has a second member having a threaded end portion that has a plurality of second holes circumferentially around the outside surface thereof. The threads of the second member are caused to threadably engage the threads of the first member for defining a threaded joint therebetween. A sleeve having an inside surface surrounds the end portion of the first member and the end portion of the second member and thus surrounds the threaded joint. The sleeve includes a plurality of first projections and second projections that outwardly extend from the inside surface to engage the first holes and the second holes, respectively. The outside surface of the sleeve is crimped or swaged at the locations of the first projections and second projections such that the first projections and the second projections engage their respective holes. In this manner, independent rotation of the first member with respect to the second member is prevented, so that the instrumentation tube will not unthread at its threaded joint.

[Demographic transition or revolution? The weaknesses and implications of the demographic transition theory. Part 1: the origins].

PubMed

Bourcier De Carbon, P

1998-01-01

The work of Adolphe Landry is reviewed in relation to development of demographic transition theory. Landry was appointed administrator in 1912 of the National Alliance Against Depopulation and remained active in it his whole life. He also helped create family allowance programs in France. As early as 1909, Landry described three different population regimes. In the "primitive" regime, which characterized all nonhuman life and human life during most of history, the population was adjusted to available subsistence by mortality. In the "intermediate" phase, restrictions on marriage and control of reproduction outside marriage maintained the population at a level below the maximum supportable. In the "contemporary" regime, the universal practice of contraception and abortion could lead to very low levels of fertility. The spread of contraception and low fertility appeared to Landry a true demographic revolution. He attributed the acceptance of contraception to a change in the common aspirations of human beings regarding their conditions, a desire for improved material well-being and social advancement, and an increased spirit of rationality and even calculation in their behavior. Landry believed that the contemporary regime, unlike the preceding two, had no mechanism implying equilibrium. The demographic revolution freed fertility from social determinants and linked it more closely to individual interests. Landry expected the contemporary regime to spread throughout the entire world, with many areas still in the primitive phase passing directly to the contemporary. He was concerned with the effects of demographic aging, and he deplored birth control propaganda that claimed it as a cure for unemployment and for overpopulation in the poor Asian countries. The birth control movements in England and the US were successful in bringing the two countries into the contemporary regime. A number of organizations such as the Population Association of America and the Office of Population Research at Princeton were favorable toward the spread of birth control through the rest of the world.

78 FR 44532 - Steel Threaded Rod From India: Initiation of Countervailing Duty Investigation

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-24

... DEPARTMENT OF COMMERCE International Trade Administration [C-533-856] Steel Threaded Rod From... Commerce (``Department'') received a countervailing duty (``CVD'') petition concerning imports of steel...\\ Petitioners are domestic producers of steel threaded rod. On July 2, and July 3, 2013, the Department...

Using online pedagogy to explore student experiences of Science-Technology-Society-Environment (STSE) issues in a secondary science classroom

NASA Astrophysics Data System (ADS)

Ayyavoo, Gabriel Roman

With the proliferation of 21st century educational technologies, science teaching and learning with digitally acclimatized learners in secondary science education can be realized through an online Science-Technology-Society-Environment (STSE)-based issues approach. STSE-based programs can be interpreted as the exploration of socially-embedded initiatives in science (e.g., use of genetically modified foods) to promote the development of critical cognitive processes and to empower learners with responsible decision-making skills. This dissertation presents a case study examining the online environment of a grade 11 physics class in an all-girls' school, and the outcomes from those online discursive opportunities with STSE materials. The limited in-class discussion opportunities are often perceived as low-quality discussions in traditional classrooms because they originate from an inadequate introduction and facilitation of socially relevant issues in science programs. Hence, this research suggests that the science curriculum should be inclusive of STSE-based issue discussions. This study also examines the nature of students' online discourse and, their perceived benefits and challenges of learning about STSE-based issues through an online environment. Analysis of interviews, offline classroom events and online threaded discussion transcripts draws from the theoretical foundations of critical reflective thinking delineated in the Practical Inquiry (P.I.) Model. The PI model of Cognitive Presence is situated within the Community of Inquiry framework, encompassing two other core elements, Teacher Presence and Social Presence. In studying Cognitive Presence, the online STSE-based discourses were examined according to the four phases of the P.I. Model. The online discussions were measured at macro-levels to reveal patterns in student STSE-based discussions and content analysis of threaded discussions. These analyses indicated that 87% of the students participated in higher quality STSE-based discussions via an online forum as compared to in-class. The micro-level analysis revealed students to attain higher cognitive interactions with STSE issues. Sixteen percent of the students' threaded postings were identified in the Resolution Phase 4 when the teacher intervened with a focused teaching strategy. This research provides a significant theoretical and pedagogical contribution to blended approach to STSE-based secondary science education. It presents a framework for teachers to facilitate students' online discussions and to support learners in exploring STSE-based topics.

Archer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Atzeni, Simone; Ahn, Dong; Gopalakrishnan, Ganesh

2017-01-12

Archer is built on top of the LLVM/Clang compilers that support OpenMP. It applies static and dynamic analysis techniques to detect data races in OpenMP programs generating a very low runtime and memory overhead. Static analyses identify data race free OpenMP regions and exclude them from runtime analysis, which is performed by ThreadSanitizer included in LLVM/Clang.

46 CFR 182.730 - Nonferrous metallic piping materials.

Code of Federal Regulations, 2011 CFR

2011-10-01

... protect piping systems using aluminum alloys in high risk fire areas due to the low melting point of aluminum alloys; (2) Provisions must be made to prevent or mitigate the effect of galvanic corrosion due to... compound must be used in making up threaded joints in aluminum pipe to prevent seizing. Pipe in the...

18F-FLT Positron Emission Tomography and Diffusion-Weighted Magnetic Resonance Imaging in Planning Surgery and Radiation Therapy and Measuring Response in Patients With Newly Diagnosed Ewing Sarcoma

ClinicalTrials.gov

2017-11-16

Adult Supratentorial Primitive Neuroectodermal Tumor (PNET); Ewing Sarcoma of Bone; Extraosseous Ewing Sarcoma; Localized Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Metastatic Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Untreated Childhood Supratentorial Primitive Neuroectodermal Tumor

19 CFR 10.16 - Assembly abroad.

Code of Federal Regulations, 2013 CFR

2013-04-01

... steps or steps incidental to assembly. Example 3. The manufacture abroad of cloth on a loom using thread... weaving operation, and the thread or yarn does not qualify for the exemption. However, American-made thread used to sew buttons or garment components is qualified for the exemption because it is used in an...

19 CFR 10.16 - Assembly abroad.

Code of Federal Regulations, 2010 CFR

2010-04-01

... steps or steps incidental to assembly. Example 3. The manufacture abroad of cloth on a loom using thread... weaving operation, and the thread or yarn does not qualify for the exemption. However, American-made thread used to sew buttons or garment components is qualified for the exemption because it is used in an...

19 CFR 10.16 - Assembly abroad.

Code of Federal Regulations, 2011 CFR

2011-04-01

... steps or steps incidental to assembly. Example 3. The manufacture abroad of cloth on a loom using thread... weaving operation, and the thread or yarn does not qualify for the exemption. However, American-made thread used to sew buttons or garment components is qualified for the exemption because it is used in an...

49 CFR 178.38 - Specification 3B seamless steel cylinders.

Code of Federal Regulations, 2012 CFR

2012-10-01

... the heat number. (d) Manufacture. Cylinders must be manufactured using equipment and processes... plugs, etc.) for those openings. Threads, conforming to the following, are required on all openings: (1) Threads must be clean cut, even, without checks, and to gauge. (2) Taper threads when used, must be of a...

49 CFR 178.38 - Specification 3B seamless steel cylinders.

Code of Federal Regulations, 2010 CFR

2010-10-01

... the heat number. (d) Manufacture. Cylinders must be manufactured using equipment and processes... plugs, etc.) for those openings. Threads, conforming to the following, are required on all openings: (1) Threads must be clean cut, even, without checks, and to gauge. (2) Taper threads when used, must be of a...

19 CFR 10.16 - Assembly abroad.

Code of Federal Regulations, 2012 CFR

2012-04-01

... steps or steps incidental to assembly. Example 3. The manufacture abroad of cloth on a loom using thread... weaving operation, and the thread or yarn does not qualify for the exemption. However, American-made thread used to sew buttons or garment components is qualified for the exemption because it is used in an...

78 FR 17642 - Determination Under the Textile and Apparel Commercial Availability Provision of the Dominican...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-22

... Agreements (``CITA'') has determined that certain piece dyed three-thread fleece fabric, as specified below... behalf of Garan Manufacturing, Inc. for certain piece dyed three-thread fleece fabric, as specified below... Commercial Availability proceedings. SPECIFICATIONS: Certain Piece Dyed Three-thread Fleece Fabric HTS: 6001...

49 CFR 178.38 - Specification 3B seamless steel cylinders.

Code of Federal Regulations, 2013 CFR

2013-10-01

... the heat number. (d) Manufacture. Cylinders must be manufactured using equipment and processes... plugs, etc.) for those openings. Threads, conforming to the following, are required on all openings: (1) Threads must be clean cut, even, without checks, and to gauge. (2) Taper threads when used, must be of a...

78 FR 17923 - Determination Under the Textile and Apparel Commercial Availability Provision of the Dominican...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-25

... Agreements (``CITA'') has determined that certain three-thread fleece fabric with soft hand pigment, as... behalf of Garan Manufacturing, Inc. for certain three-thread fleece fabric with soft hand pigment, as... dedicated Web site for CAFTA-DR Commercial Availability proceedings. Specifications: Certain Three-Thread...

49 CFR 178.38 - Specification 3B seamless steel cylinders.

Code of Federal Regulations, 2014 CFR

2014-10-01

... the heat number. (d) Manufacture. Cylinders must be manufactured using equipment and processes... plugs, etc.) for those openings. Threads, conforming to the following, are required on all openings: (1) Threads must be clean cut, even, without checks, and to gauge. (2) Taper threads when used, must be of a...

19 CFR 10.16 - Assembly abroad.

Code of Federal Regulations, 2014 CFR

2014-04-01

... steps or steps incidental to assembly. Example 3. The manufacture abroad of cloth on a loom using thread... weaving operation, and the thread or yarn does not qualify for the exemption. However, American-made thread used to sew buttons or garment components is qualified for the exemption because it is used in an...

78 FR 71565 - Steel Threaded Rod from India: Postponement of Preliminary Determination of Antidumping Duty...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-29

... India: Postponement of Preliminary Determination of Antidumping Duty Investigation AGENCY: Enforcement... antidumping duty investigation of steel threaded rod from India.\\1\\ The notice of initiation stated that the... Steel Threaded Rod From India and Thailand: Initiation of Antidumping Duty Investigations, 78 FR 44526...

78 FR 7414 - Determination Under the Textile and Apparel Commercial Availability Provision of the Dominican...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-01

... Agreements (``CITA'') has determined that certain cotton/polyester three-thread circular knit fleece fabric... behalf of Intradeco Apparel, Inc. for certain cotton/polyester three-thread circular knit fleece fabric.... Specifications: Certain Cotton/Polyester Three-Thread Circular Knit Fleece Fabric HTS: 6001.21 Fiber content...

An MPI-1 Compliant Thread-Based Implementation

NASA Astrophysics Data System (ADS)

Díaz Martín, J. C.; Rico Gallego, J. A.; Álvarez Llorente, J. M.; Perogil Duque, J. F.

This work presents AzequiaMPI, the first full compliant implementation of the MPI-1 standard where the MPI node is a thread. Performance comparisons with MPICH2-Nemesis show that thread-based implementations exploit adequately the multicore architectures under oversubscription, what could make MPI competitive with OpenMP-like solutions.

Debugging a high performance computing program

DOEpatents

Gooding, Thomas M.

2014-08-19

Methods, apparatus, and computer program products are disclosed for debugging a high performance computing program by gathering lists of addresses of calling instructions for a plurality of threads of execution of the program, assigning the threads to groups in dependence upon the addresses, and displaying the groups to identify defective threads.

Debugging a high performance computing program

DOEpatents

Gooding, Thomas M.

2013-08-20

Methods, apparatus, and computer program products are disclosed for debugging a high performance computing program by gathering lists of addresses of calling instructions for a plurality of threads of execution of the program, assigning the threads to groups in dependence upon the addresses, and displaying the groups to identify defective threads.

Exploiting Thread Parallelism for Ocean Modeling on Cray XC Supercomputers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sarje, Abhinav; Jacobsen, Douglas W.; Williams, Samuel W.

The incorporation of increasing core counts in modern processors used to build state-of-the-art supercomputers is driving application development towards exploitation of thread parallelism, in addition to distributed memory parallelism, with the goal of delivering efficient high-performance codes. In this work we describe the exploitation of threading and our experiences with it with respect to a real-world ocean modeling application code, MPAS-Ocean. We present detailed performance analysis and comparisons of various approaches and configurations for threading on the Cray XC series supercomputers.

Multithreading in vector processors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Evangelinos, Constantinos; Kim, Changhoan; Nair, Ravi

In one embodiment, a system includes a processor having a vector processing mode and a multithreading mode. The processor is configured to operate on one thread per cycle in the multithreading mode. The processor includes a program counter register having a plurality of program counters, and the program counter register is vectorized. Each program counter in the program counter register represents a distinct corresponding thread of a plurality of threads. The processor is configured to execute the plurality of threads by activating the plurality of program counters in a round robin cycle.

Parallel Lattice Basis Reduction Using a Multi-threaded Schnorr-Euchner LLL Algorithm

NASA Astrophysics Data System (ADS)

Backes, Werner; Wetzel, Susanne

In this paper, we introduce a new parallel variant of the LLL lattice basis reduction algorithm. Our new, multi-threaded algorithm is the first to provide an efficient, parallel implementation of the Schorr-Euchner algorithm for today’s multi-processor, multi-core computer architectures. Experiments with sparse and dense lattice bases show a speed-up factor of about 1.8 for the 2-thread and about factor 3.2 for the 4-thread version of our new parallel lattice basis reduction algorithm in comparison to the traditional non-parallel algorithm.

SWAYING THREADS OF A SOLAR FILAMENT

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lin, Y.; Engvold, O.; Langangen, Oe.

From recent high-resolution observations obtained with the Swedish 1 m Solar Telescope in La Palma, we detect swaying motions of individual filament threads in the plane of the sky. The oscillatory characters of these motions are comparable with oscillatory Doppler signals obtained from corresponding filament threads. Simultaneous recordings of motions in the line of sight and in the plane of the sky give information about the orientation of the oscillatory plane. These oscillations are interpreted in the context of the magnetohydrodynamic (MHD) theory. Kink MHD waves supported by the thread body are proposed as an explanation of the observed threadmore » oscillations. On the basis of this interpretation and by means of seismological arguments, we give an estimation of the thread Alfven speed and magnetic field strength by means of seismological arguments.« less

Mobile Thread Task Manager

NASA Technical Reports Server (NTRS)

Clement, Bradley J.; Estlin, Tara A.; Bornstein, Benjamin J.

2013-01-01

The Mobile Thread Task Manager (MTTM) is being applied to parallelizing existing flight software to understand the benefits and to develop new techniques and architectural concepts for adapting software to multicore architectures. It allocates and load-balances tasks for a group of threads that migrate across processors to improve cache performance. In order to balance-load across threads, the MTTM augments a basic map-reduce strategy to draw jobs from a global queue. In a multicore processor, memory may be "homed" to the cache of a specific processor and must be accessed from that processor. The MTTB architecture wraps access to data with thread management to move threads to the home processor for that data so that the computation follows the data in an attempt to avoid L2 cache misses. Cache homing is also handled by a memory manager that translates identifiers to processor IDs where the data will be homed (according to rules defined by the user). The user can also specify the number of threads and processors separately, which is important for tuning performance for different patterns of computation and memory access. MTTM efficiently processes tasks in parallel on a multiprocessor computer. It also provides an interface to make it easier to adapt existing software to a multiprocessor environment.

Manyscale Computing for Sensor Processing in Support of Space Situational Awareness

NASA Astrophysics Data System (ADS)

Schmalz, M.; Chapman, W.; Hayden, E.; Sahni, S.; Ranka, S.

2014-09-01

Increasing image and signal data burden associated with sensor data processing in support of space situational awareness implies continuing computational throughput growth beyond the petascale regime. In addition to growing applications data burden and diversity, the breadth, diversity and scalability of high performance computing architectures and their various organizations challenge the development of a single, unifying, practicable model of parallel computation. Therefore, models for scalable parallel processing have exploited architectural and structural idiosyncrasies, yielding potential misapplications when legacy programs are ported among such architectures. In response to this challenge, we have developed a concise, efficient computational paradigm and software called Manyscale Computing to facilitate efficient mapping of annotated application codes to heterogeneous parallel architectures. Our theory, algorithms, software, and experimental results support partitioning and scheduling of application codes for envisioned parallel architectures, in terms of work atoms that are mapped (for example) to threads or thread blocks on computational hardware. Because of the rigor, completeness, conciseness, and layered design of our manyscale approach, application-to-architecture mapping is feasible and scalable for architectures at petascales, exascales, and above. Further, our methodology is simple, relying primarily on a small set of primitive mapping operations and support routines that are readily implemented on modern parallel processors such as graphics processing units (GPUs) and hybrid multi-processors (HMPs). In this paper, we overview the opportunities and challenges of manyscale computing for image and signal processing in support of space situational awareness applications. We discuss applications in terms of a layered hardware architecture (laboratory > supercomputer > rack > processor > component hierarchy). Demonstration applications include performance analysis and results in terms of execution time as well as storage, power, and energy consumption for bus-connected and/or networked architectures. The feasibility of the manyscale paradigm is demonstrated by addressing four principal challenges: (1) architectural/structural diversity, parallelism, and locality, (2) masking of I/O and memory latencies, (3) scalability of design as well as implementation, and (4) efficient representation/expression of parallel applications. Examples will demonstrate how manyscale computing helps solve these challenges efficiently on real-world computing systems.

Organic matter on asteroid 130 Elektra

NASA Technical Reports Server (NTRS)

Cruikshank, D. P.; Brown, R. H.

1987-01-01

Infrared absorption spectra of a low-albedo water-rich asteroid appear to show a weak 3.4-micrometer carbon-hydrogen stretching mode band, which suggests the presence of hydrocarbons on asteroid 130 Elektra. The organic extract from the primitive carbonaceous chondritic Murchison meteorite shows similar spectral bands.

Probabilistic evaluation of fuselage-type composite structures

NASA Technical Reports Server (NTRS)

Shiao, Michael C.; Chamis, Christos C.

1992-01-01

A methodology is developed to computationally simulate the uncertain behavior of composite structures. The uncertain behavior includes buckling loads, natural frequencies, displacements, stress/strain etc., which are the consequences of the random variation (scatter) of the primitive (independent random) variables in the constituent, ply, laminate and structural levels. This methodology is implemented in the IPACS (Integrated Probabilistic Assessment of Composite Structures) computer code. A fuselage-type composite structure is analyzed to demonstrate the code's capability. The probability distribution functions of the buckling loads, natural frequency, displacement, strain and stress are computed. The sensitivity of each primitive (independent random) variable to a given structural response is also identified from the analyses.

Optimisation of an idealised primitive equation ocean model using stochastic parameterization

NASA Astrophysics Data System (ADS)

Cooper, Fenwick C.

2017-05-01

Using a simple parameterization, an idealised low resolution (biharmonic viscosity coefficient of 5 × 1012 m4s-1 , 128 × 128 grid) primitive equation baroclinic ocean gyre model is optimised to have a much more accurate climatological mean, variance and response to forcing, in all model variables, with respect to a high resolution (biharmonic viscosity coefficient of 8 × 1010 m4s-1 , 512 × 512 grid) equivalent. For example, the change in the climatological mean due to a small change in the boundary conditions is more accurate in the model with parameterization. Both the low resolution and high resolution models are strongly chaotic. We also find that long timescales in the model temperature auto-correlation at depth are controlled by the vertical temperature diffusion parameter and time mean vertical advection and are caused by short timescale random forcing near the surface. This paper extends earlier work that considered a shallow water barotropic gyre. Here the analysis is extended to a more turbulent multi-layer primitive equation model that includes temperature as a prognostic variable. The parameterization consists of a constant forcing, applied to the velocity and temperature equations at each grid point, which is optimised to obtain a model with an accurate climatological mean, and a linear stochastic forcing, that is optimised to also obtain an accurate climatological variance and 5 day lag auto-covariance. A linear relaxation (nudging) is not used. Conservation of energy and momentum is discussed in an appendix.

Thermal Preload Relaxation of Bolted CFRP Structures for Flexible Life Time Design Methodology

NASA Astrophysics Data System (ADS)

Hubbertz, Hendrik; Friedrich, Christoph

2014-06-01

Taking into account the assembly, maintenance and repair of component systems, it becomes clear that mechanical fastening is necessary also for CFRP structures besides adhesive bonding. Threaded fasteners usually prestress CFRP materials perpendicular to the fibres. In this direction the high strength-increase by the carbon fibres is subordinated and the material properties are dominated by the relatively low strength plastic matrix. The following chapters explain the basics of preload loss at threaded fasteners and show the results of experiments with different influences on preload relaxation with CFRP materials. As the presented studies were carried out under the influence of temperature, thermal load plastification will be regarded as priority. The structural changes in the material are also documented with microscope images as well as an outlook for further research is given.

Submarine alkalic through tholeiitic shield-stage development of Kīlauea volcano, Hawai'i

NASA Astrophysics Data System (ADS)

Sisson, Thomas W.; Lipman, Peter W.; Naka, Jiro

The submarine Hilina region exposes a succession of magma compositions spanning the juvenile "Lō'ihi" through tholeiitic shield stages of Kīlauea volcano. Early products, preserved as glass grains and clasts in volcaniclastic rocks of the 3000 m deep Hilina bench, include nephelinite, basanite, phonotephrite, hawaiite, alkali basalt, transitional basalt, and rare alkali-poor Mauna Loa-like tholeiite. Transitional basalt pillow lavas overlie the volcaniclastic section and record an early phase of subsequent subalkaline magmatism. Rare degassed tholeiitic pillow lava and talus above the volcaniclastic section are products of subaerial shield volcanism. Major and trace element variations of clasts and pillow lavas point to a factor of 2-2.5 increase in degree of melting from juvenile alkalic to modern tholeiitic Kīlauea. Progressive changes in element ratios that distinguish Hawaiian shield volcanoes, without commensurate changes in elements fractionated by partial melting, also signal increased contributions from Mauna Loa-type source regions as Kīlauea matured from its juvenile alkalic to its tholeiitic shield stage. Ancestral Kīlauea basanites and nephelinites were not primitive magmas but might have evolved from plume-derived alkali picritic parents by lithospheric-level crystallization differentiation, or solidification and remelting, involving pyroxene and garnet, similar to the subcrustal differentiation origin of hawaiites [Frey et al., 1990]. Low magmatic productivity early in Kīlauea's history sustained a poorly integrated trans-lithospheric conduit system in which magmas stalled and differentiated, producing evolved hawaiites, nephelinites, and basanites. This contrasts with shield-stage Kīlauea where high magmatic productivity flushes the conduit system and delivers primitive magmas to shallow levels.

Clean home-delivery in rural Southern Tanzania: barriers, influencers, and facilitators.

PubMed

Shamba, Donat D; Schellenberg, Joanna; Penfold, Suzanne C; Mashasi, Irene; Mrisho, Mwifadhi; Manzi, Fatuma; Marchant, Tanya; Tanner, Marcel; Mshinda, Hassan; Schellenberg, David; Hill, Zelee

2013-03-01

The study explored the childbirth-related hygiene and newborn care practices in home-deliveries in Southern Tanzania and barriers to and facilitators of behaviour change. Eleven home-birth narratives and six focus group discussions were conducted with recently-delivering women; two focus group discussions were conducted with birth attendants. The use of clean cloth for delivery was reported as common in the birth narratives; however, respondents did not link its use to newborn's health. Handwashing and wearing of gloves by birth attendants varied and were not discussed in terms of being important for newborn's health, with few women giving reasons for this behaviour. The lack of handwashing and wearing of gloves was most commonly linked to the lack of water, gloves, and awareness. A common practice was the insertion of any family member's hands into the vagina of delivering woman to check labour progress before calling the birth attendant. The use of a new razor blade to cut the cord was near-universal; however, the cord was usually tied with a used thread due to the lack of knowledge and the low availability of clean thread. Applying something to the cord was near-universal and was considered essential for newborn's health. Three hygiene practices were identified as needing improvement: family members inserting a hand into the vagina of delivering woman before calling the birth attendant, the use of unclean thread, and putting substances on the cord. Little is known about families conducting internal checks of women in labour, and more research is needed before this behaviour is targeted in interventions. The use of clean thread as cord-tie appears acceptable and can be addressed, using the same channels and methods that were used for successfully encouraging the use of new razor blade.

XMOS XC-2 Development Board for Mechanical Control and Data Collection

NASA Technical Reports Server (NTRS)

Jarnot, Robert F.; Bowden, William J.

2011-01-01

The scanning microwave limb sounder (SMLS) will use technological improvements in low-noise mixers to provide precise data on the Earth s atmospheric composition with high spatial resolution. This project focuses on the design and implementation of a realtime control system needed for airborne engineering tests of the SMLS. The system must coordinate the actuation of optical components using four motors with encoder readback, while collecting synchronized telemetric data from a GPS receiver and 3-axis gyrometric system. A graphical user interface for testing the control system was also designed using Python. Although the system could have been implemented with an FPGA(fieldprogrammable gate array)-based setup, a processor development kit manufactured by XMOS was chosen. The XMOS architecture allows parallel execution of multiple tasks on separate threads, making it ideal for this application. It is easily programmed using XC (a subset of C). The necessary communication interfaces were implemented in software, including Ethernet, with significant cost and time reduction compared to an FPGA-based approach. A simple approach to control the chopper, calibration mirror, and gimbal for the airborne SMLS was needed. The XMOS board allows for multiple threads and real-time data acquisition. The XC-2 development kit is an attractive choice for synchronized, real-time, event-driven applications. The XMOS is based on the transputer microprocessor architecture developed for parallel computing, which is being revamped in this new platform. The XMOS device has multiple cores capable of running parallel applications on separate threads. The threads communicate with each other via user-defined channels capable of transmitting data within the device. XMOS provides a C-based development environment using XC, which eliminates the need for custom tool kits associated with FPGA programming. The XC-2 has four cores and necessary hardware for Ethernet I/O.

Human stem cell decorated nanocellulose threads for biomedical applications.

PubMed

Mertaniemi, Henrikki; Escobedo-Lucea, Carmen; Sanz-Garcia, Andres; Gandía, Carolina; Mäkitie, Antti; Partanen, Jouni; Ikkala, Olli; Yliperttula, Marjo

2016-03-01

Upon surgery, local inflammatory reactions and postoperative infections cause complications, morbidity, and mortality. Delivery of human adipose mesenchymal stem cells (hASC) into the wounds is an efficient and safe means to reduce inflammation and promote wound healing. However, administration of stem cells by injection often results in low cell retention, and the cells deposit in other organs, reducing the efficiency of the therapy. Thus, it is essential to improve cell delivery to the target area using carriers to which the cells have a high affinity. Moreover, the application of hASC in surgery has typically relied on animal-origin components, which may induce immune reactions or even transmit infections due to pathogens. To solve these issues, we first show that native cellulose nanofibers (nanofibrillated cellulose, NFC) extracted from plants allow preparation of glutaraldehyde cross-linked threads (NFC-X) with high mechanical strength even under the wet cell culture or surgery conditions, characteristically challenging for cellulosic materials. Secondly, using a xenogeneic free protocol for isolation and maintenance of hASC, we demonstrate that cells adhere, migrate and proliferate on the NFC-X, even without surface modifiers. Cross-linked threads were not found to induce toxicity on the cells and, importantly, hASC attached on NFC-X maintained their undifferentiated state and preserved their bioactivity. After intradermal suturing with the hASC decorated NFC-X threads in an ex vivo experiment, cells remained attached to the multifilament sutures without displaying morphological changes or reducing their metabolic activity. Finally, as NFC-X optionally allows facile surface tailoring if needed, we anticipate that stem-cell-decorated NFC-X opens a versatile generic platform as a surgical bionanomaterial for fighting postoperative inflammation and chronic wound healing problems. Copyright © 2015 Elsevier Ltd. All rights reserved.

Acoustic reverse-time migration using GPU card and POSIX thread based on the adaptive optimal finite-difference scheme and the hybrid absorbing boundary condition

NASA Astrophysics Data System (ADS)

Cai, Xiaohui; Liu, Yang; Ren, Zhiming

2018-06-01

Reverse-time migration (RTM) is a powerful tool for imaging geologically complex structures such as steep-dip and subsalt. However, its implementation is quite computationally expensive. Recently, as a low-cost solution, the graphic processing unit (GPU) was introduced to improve the efficiency of RTM. In the paper, we develop three ameliorative strategies to implement RTM on GPU card. First, given the high accuracy and efficiency of the adaptive optimal finite-difference (FD) method based on least squares (LS) on central processing unit (CPU), we study the optimal LS-based FD method on GPU. Second, we develop the CPU-based hybrid absorbing boundary condition (ABC) to the GPU-based one by addressing two issues of the former when introduced to GPU card: time-consuming and chaotic threads. Third, for large-scale data, the combinatorial strategy for optimal checkpointing and efficient boundary storage is introduced for the trade-off between memory and recomputation. To save the time of communication between host and disk, the portable operating system interface (POSIX) thread is utilized to create the other CPU core at the checkpoints. Applications of the three strategies on GPU with the compute unified device architecture (CUDA) programming language in RTM demonstrate their efficiency and validity.

The Formation of a Small-Scale Filament After Flux Emergence on the Quiet Sun

NASA Astrophysics Data System (ADS)

Chen, Hechao; Yang, Jiayan; Yang, Bo; Ji, Kaifan; Bi, Yi

2018-06-01

We present observations of the formation process of a small-scale filament on the quiet Sun during 5 - 6 February 2016 and investigate its formation cause. Initially, a small dipole emerged, and its associated arch filament system was found to reconnect with overlying coronal fields accompanied by numerous extreme ultraviolet bright points. When the bright points faded, many elongated dark threads formed and bridged the positive magnetic element of the dipole and the external negative network fields. Interestingly, an anticlockwise photospheric rotational motion (PRM) set in within the positive endpoint region of the newborn dark threads following the flux emergence and lasted for more than 10 hours. Under the drive of the PRM, these dispersive dark threads gradually aligned along the north-south direction and finally coalesced into an inverse S-shaped filament. Consistent with the dextral chirality of the filament, magnetic helicity calculations show that an amount of negative helicity was persistently injected from the rotational positive magnetic element and accumulated during the formation of the filament. These observations suggest that twisted emerging fields may lead to the formation of the filament via reconnection with pre-existing fields and release of its inner magnetic twist. The persistent PRM might trace a covert twist relaxation from below the photosphere to the low corona.

Damping of prominence longitudinal oscillations due to mass accretion

NASA Astrophysics Data System (ADS)

Ruderman, Michael S.; Luna, Manuel

2016-06-01

We study the damping of longitudinal oscillations of a prominence thread caused by the mass accretion. We suggested a simple model describing this phenomenon. In this model we considered a thin curved magnetic tube filled with the plasma. The prominence thread is in the central part of the tube and it consists of dense cold plasma. The parts of the tube at the two sides of the thread are filled with hot rarefied plasma. We assume that there are flows of rarefied plasma toward the thread caused by the plasma evaporation at the magnetic tube footpoints. Our main assumption is that the hot plasma is instantaneously accommodated by the thread when it arrives at the thread, and its temperature and density become equal to those of the thread. Then we derive the system of ordinary differential equations describing the thread dynamics. We solve this system of ordinary differential equations in two particular cases. In the first case we assume that the magnetic tube is composed of an arc of a circle with two straight lines attached to its ends such that the whole curve is smooth. A very important property of this model is that the equations describing the thread oscillations are linear for any oscillation amplitude. We obtain the analytical solution of the governing equations. Then we obtain the analytical expressions for the oscillation damping time and periods. We find that the damping time is inversely proportional to the accretion rate. The oscillation periods increase with time. We conclude that the oscillations can damp in a few periods if the inclination angle is sufficiently small, not larger that 10°, and the flow speed is sufficiently large, not less that 30 km s-1. In the second model we consider the tube with the shape of an arc of a circle. The thread oscillates with the pendulum frequency dependent exclusively on the radius of curvature of the arc. The damping depends on the mass accretion rate and the initial mass of the threads, that is the mass of the thread at the moment when it is perturbed. First we consider small amplitude oscillations and use the linear description. Then we consider nonlinear oscillations and assume that the damping is slow, meaning that the damping time is much larger that the characteristic oscillation time. The thread oscillations are described by the solution of the nonlinear pendulum problem with slowly varying amplitude. The nonlinearity reduces the damping time, however this reduction is small. Again the damping time is inversely proportional to the accretion rate. We also obtain that the oscillation periods decrease with time. However even for the largest initial oscillation amplitude considered in our article the period reduction does not exceed 20%. We conclude that the mass accretion can damp the motion of the threads rapidly. Thus, this mechanism can explain the observed strong damping of large-amplitude longitudinal oscillations. In addition, the damping time can be used to determine the mass accretion rate and indirectly the coronal heating.

Diagnostic Study of Tumor Characteristics in Patients With Ewing's Sarcoma

ClinicalTrials.gov

2013-06-20

Localized Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Metastatic Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Recurrent Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor

Modern multicore and manycore architectures: Modelling, optimisation and benchmarking a multiblock CFD code

NASA Astrophysics Data System (ADS)

Hadade, Ioan; di Mare, Luca

2016-08-01

Modern multicore and manycore processors exhibit multiple levels of parallelism through a wide range of architectural features such as SIMD for data parallel execution or threads for core parallelism. The exploitation of multi-level parallelism is therefore crucial for achieving superior performance on current and future processors. This paper presents the performance tuning of a multiblock CFD solver on Intel SandyBridge and Haswell multicore CPUs and the Intel Xeon Phi Knights Corner coprocessor. Code optimisations have been applied on two computational kernels exhibiting different computational patterns: the update of flow variables and the evaluation of the Roe numerical fluxes. We discuss at great length the code transformations required for achieving efficient SIMD computations for both kernels across the selected devices including SIMD shuffles and transpositions for flux stencil computations and global memory transformations. Core parallelism is expressed through threading based on a number of domain decomposition techniques together with optimisations pertaining to alleviating NUMA effects found in multi-socket compute nodes. Results are correlated with the Roofline performance model in order to assert their efficiency for each distinct architecture. We report significant speedups for single thread execution across both kernels: 2-5X on the multicore CPUs and 14-23X on the Xeon Phi coprocessor. Computations at full node and chip concurrency deliver a factor of three speedup on the multicore processors and up to 24X on the Xeon Phi manycore coprocessor.

Silk-Quality, Spinnability and Low Temperature Behavior

DTIC Science & Technology

2015-12-02

dry  silk  radial  and   web  frame  threads.    In   this  study  we  experimentally  demonstrated...green  dashed  line),   nylon  (orange),  Nephila  major  ampullate  spider  silk  ( dry :  black,  wet:  cyan).  Asterisk...gives  low  tension,   dry   Aciniform  spider  silk.  [  33  ]  For  the  major

Memory Benchmarks for SMP-Based High Performance Parallel Computers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yoo, A B; de Supinski, B; Mueller, F

2001-11-20

As the speed gap between CPU and main memory continues to grow, memory accesses increasingly dominates the performance of many applications. The problem is particularly acute for symmetric multiprocessor (SMP) systems, where the shared memory may be accessed concurrently by a group of threads running on separate CPUs. Unfortunately, several key issues governing memory system performance in current systems are not well understood. Complex interactions between the levels of the memory hierarchy, buses or switches, DRAM back-ends, system software, and application access patterns can make it difficult to pinpoint bottlenecks and determine appropriate optimizations, and the situation is even moremore » complex for SMP systems. To partially address this problem, we formulated a set of multi-threaded microbenchmarks for characterizing and measuring the performance of the underlying memory system in SMP-based high-performance computers. We report our use of these microbenchmarks on two important SMP-based machines. This paper has four primary contributions. First, we introduce a microbenchmark suite to systematically assess and compare the performance of different levels in SMP memory hierarchies. Second, we present a new tool based on hardware performance monitors to determine a wide array of memory system characteristics, such as cache sizes, quickly and easily; by using this tool, memory performance studies can be targeted to the full spectrum of performance regimes with many fewer data points than is otherwise required. Third, we present experimental results indicating that the performance of applications with large memory footprints remains largely constrained by memory. Fourth, we demonstrate that thread-level parallelism further degrades memory performance, even for the latest SMPs with hardware prefetching and switch-based memory interconnects.« less

Temperature mediates the effect of humidity on the viscoelasticity of glycoprotein glue within the droplets of an orb-weaving spider's prey capture threads.

PubMed

Stellwagen, Sarah D; Opell, Brent D; Short, Kelly G

2014-05-01

Sticky viscous prey capture threads retain insects that strike araneoid orb-webs. The threads' two axial fibers support a series of glue droplets, each featuring a core of adhesive viscoelastic glycoprotein covered by an aqueous solution. After sticking, the glue extends, summing the adhesion of multiple droplets, and dissipates some of the energy of a struggling prey. As a day progresses, threads experience a drop in humidity and an increase in temperature, environmental variables that have the potential to alter thread and web function. We hypothesize that thread droplets respond to these opposing environmental changes in a manner that stabilizes their performance, and test this by examining threads spun by Argiope aurantia, a species that occupies exposed, weedy habitats. We confirmed that decreased humidity increases glycoprotein viscosity and found that increased temperature had the opposite effect. To evaluate the combined effect of temperature and humidity on a droplet's ability to transfer adhesive force and dissipate energy, we extended a droplet and measured both the deflection of the axial line supporting the droplet and the duration of its tensive load. The cumulative product of these two indices, which reflects the energy required to extend a droplet, was greatest under afternoon (hot and dry) conditions, less under morning (cool and humid) conditions, and least under hot and humid afternoon conditions. Although the opposing effects of temperature and humidity tend to stabilize glycoprotein performance, A. aurantia thread droplets appear to function optimally during the afternoon, equipping this species to capture large orthopterans, which are most active at this time.

FNCS: A Framework for Power System and Communication Networks Co-Simulation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ciraci, Selim; Daily, Jeffrey A.; Fuller, Jason C.

2014-04-13

This paper describes the Fenix framework that uses a federated approach for integrating power grid and communication network simulators. Compared existing approaches, Fenix al- lows co-simulation of both transmission and distribution level power grid simulators with the communication network sim- ulator. To reduce the performance overhead of time synchro- nization, Fenix utilizes optimistic synchronization strategies that make speculative decisions about when the simulators are going to exchange messages. GridLAB-D (a distribution simulator), PowerFlow (a transmission simulator), and ns-3 (a telecommunication simulator) are integrated with the frame- work and are used to illustrate the enhanced performance pro- vided by speculative multi-threadingmore » on a smart grid applica- tion. Our speculative multi-threading approach achieved on average 20% improvement over the existing synchronization methods« less

Nano-enabled sensors, electronics and energy source on polymer, paper and thread substrates

NASA Astrophysics Data System (ADS)

Mostafalu, Pooria

Over the past decades, design and development of portable devices for monitoring of biomarkers especially for at risk patients is receiving considerable attention. These devices are either single use diagnostic platforms, wearable on body or on fabric, or they are implanted close to the tissue and organ that it monitors and cures. Sensors, energy sources, and data acquisition devices are the main components of a such monitoring platform. Sensors collect the information using bio-recognition tools such as enzymes and antibodies. Then, the transducers (electrodes, fluorophore, etc) convert it to the appropriate format, for instance electrical and optical signals. After that, data acquisition system amplifies and digitizes the signal and transfers the data to the recording instruments for further processing. Moreover, energy sources are necessary for powering the sensors and electronics. In wearable and implantable applications, these devices need to be flexible, light weight and biocompatible, and their performance should be similar to their rigid counterparts. In this dissertation we address these requirement for wearable and implantable devices. We showed integrated sensors, electronics, and energy sources on flexible polymers, paper, and thread. These devices provide many advantages for monitoring of the physiological condition of a patient and treatment accordingly. Real-time capability of the platform was enabled using wireless telemetry. One of the major innovations of this dissertation is the use of thread as a substrate for making medical diagnostic devices. While conventional substrates (glass, silicon, polyimide, PDMS etc) hold great promise for making wearable and implantable devices, their overall structure and form has remained essentially two dimensional, limiting their function to tissue surfaces such as skin. However, the ability to integrate functional components such as sensors, actuators, and electronics in a way that they penetrate multiple layers of tissues in a 3D topology would be a significant surgical advance. We have devised an integrated thread-based diagnostic (TDD) system with the ability to measure physical (strain and temperature) and chemical (pH and glucose) markers in the body in vivo. Such device was made from threads, which have been widely used in the apparel industry and is readily available as a low-cost biocompatible material.

Object-based warping: an illusory distortion of space within objects.

PubMed

Vickery, Timothy J; Chun, Marvin M

2010-12-01

Visual objects are high-level primitives that are fundamental to numerous perceptual functions, such as guidance of attention. We report that objects warp visual perception of space in such a way that spatial distances within objects appear to be larger than spatial distances in ground regions. When two dots were placed inside a rectangular object, they appeared farther apart from one another than two dots with identical spacing outside of the object. To investigate whether this effect was object based, we measured the distortion while manipulating the structure surrounding the dots. Object displays were constructed with a single object, multiple objects, a partially occluded object, and an illusory object. Nonobject displays were constructed to be comparable to object displays in low-level visual attributes. In all cases, the object displays resulted in a more powerful distortion of spatial perception than comparable non-object-based displays. These results suggest that perception of space within objects is warped.

Collecting and Storing Biological Samples From Patients With Ewing Sarcoma

ClinicalTrials.gov

2017-12-11

Askin Tumor; Localized Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Metastatic Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Recurrent Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor

78 FR 40170 - Certain Steel Threaded Rod From India and Thailand; Institution of Antidumping and Countervailing...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-03

... INTERNATIONAL TRADE COMMISSION [Investigation Nos. 701-TA-498 and 731-TA-1213-1214 (Preliminary)] Certain Steel Threaded Rod From India and Thailand; Institution of Antidumping and Countervailing Duty... Thailand of certain steel threaded rod, provided for primarily in subheading 7318.15.50 of the Harmonized...

21 CFR 888.3040 - Smooth or threaded metallic bone fixation fastener.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Smooth or threaded metallic bone fixation fastener... metallic bone fixation fastener. (a) Identification. A smooth or threaded metallic bone fixation fastener..., slotted head on the end. It may be used for fixation of bone fractures, for bone reconstructions, as a...

21 CFR 888.3040 - Smooth or threaded metallic bone fixation fastener.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Smooth or threaded metallic bone fixation fastener... metallic bone fixation fastener. (a) Identification. A smooth or threaded metallic bone fixation fastener..., slotted head on the end. It may be used for fixation of bone fractures, for bone reconstructions, as a...

21 CFR 888.3040 - Smooth or threaded metallic bone fixation fastener.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Smooth or threaded metallic bone fixation fastener... metallic bone fixation fastener. (a) Identification. A smooth or threaded metallic bone fixation fastener..., slotted head on the end. It may be used for fixation of bone fractures, for bone reconstructions, as a...

21 CFR 888.3040 - Smooth or threaded metallic bone fixation fastener.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Smooth or threaded metallic bone fixation fastener... metallic bone fixation fastener. (a) Identification. A smooth or threaded metallic bone fixation fastener..., slotted head on the end. It may be used for fixation of bone fractures, for bone reconstructions, as a...

21 CFR 888.3040 - Smooth or threaded metallic bone fixation fastener.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Smooth or threaded metallic bone fixation fastener... metallic bone fixation fastener. (a) Identification. A smooth or threaded metallic bone fixation fastener..., slotted head on the end. It may be used for fixation of bone fractures, for bone reconstructions, as a...

76 FR 77369 - Airworthiness Directives; Piaggio Aero Industries S.p.A. Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-13

... installed on the door handle for proper tightness and correct as necessary after applying a thread locker... thread locker following Part D of the Accomplishment Instructions in Piaggio Aero Industries S.p.A... necessary after applying a thread locker following Part D of the Accomplishment Instructions in Piaggio Aero...

49 CFR 178.36 - Specification 3A and 3AX seamless steel cylinders.

Code of Federal Regulations, 2012 CFR

2012-10-01

.... Cylinders must be manufactured using equipment and processes adequate to ensure that each cylinder produced... openings. Threads are required on openings. (1) Threads must be clean cut, even, without checks, and to gauge. (2) Taper threads, when used, must be of length not less than as specified for American Standard...

49 CFR 178.45 - Specification 3T seamless steel cylinder.

Code of Federal Regulations, 2012 CFR

2012-10-01

..., or electric furnace process steel of uniform quality is authorized. The steel analysis must conform... inches in diameter. (4) All openings must be circular. (5) All openings must be threaded. Threads must be in compliance with the following: (i) Each thread must be clean cut, even, without any checks, and to...

16 CFR 1632.4 - Mattress test procedure.

Code of Federal Regulations, 2014 CFR

2014-01-01

... directly over the thread or in the depression created by the quilting process on the half of the test... characteristic such as permanent press or flame resistance. It shall have 120-210 threads per square inch and... their full lengths over the thread or depression, then the cigarettes shall be positioned in a manner...

49 CFR 178.56 - Specification 4AA480 welded steel cylinders.

Code of Federal Regulations, 2014 CFR

2014-10-01

... by spinning process not permitted. (b) Steel. The limiting chemical composition of steel authorized... equipment and processes adequate to ensure that each cylinder produced conforms to the requirements of this... welding or by threads. If threads are used they must comply with the following: (i) Threads must be clean...

49 CFR 178.45 - Specification 3T seamless steel cylinder.

Code of Federal Regulations, 2014 CFR

2014-10-01

..., or electric furnace process steel of uniform quality is authorized. The steel analysis must conform... inches in diameter. (4) All openings must be circular. (5) All openings must be threaded. Threads must be in compliance with the following: (i) Each thread must be clean cut, even, without any checks, and to...

49 CFR 178.56 - Specification 4AA480 welded steel cylinders.

Code of Federal Regulations, 2010 CFR

2010-10-01

... by spinning process not permitted. (b) Steel. The limiting chemical composition of steel authorized... equipment and processes adequate to ensure that each cylinder produced conforms to the requirements of this... welding or by threads. If threads are used they must comply with the following: (i) Threads must be clean...

49 CFR 178.45 - Specification 3T seamless steel cylinder.

Code of Federal Regulations, 2013 CFR

2013-10-01

..., or electric furnace process steel of uniform quality is authorized. The steel analysis must conform... inches in diameter. (4) All openings must be circular. (5) All openings must be threaded. Threads must be in compliance with the following: (i) Each thread must be clean cut, even, without any checks, and to...

16 CFR 1512.4 - Mechanical requirements.

Code of Federal Regulations, 2012 CFR

2012-01-01

... of edges, or any burrs or spurs caused during the shearing process. (c) Integrity. There shall be no.... Recommended quality thread form is specified in Handbook H28, “Screw Thread Standards for Federal Service,” 1..., 262, and 263, “General Purpose Screw Threads.” 2 1 Copies may be obtained from: Superintendent of...

16 CFR 1632.4 - Mattress test procedure.

Code of Federal Regulations, 2011 CFR

2011-01-01

... directly over the thread or in the depression created by the quilting process on the half of the test... as permanent press or flame resistance. It shall have 120-210 threads per square inch and fabric... their full lengths over the thread or depression, then the cigarettes shall be positioned in a manner...

49 CFR 178.56 - Specification 4AA480 welded steel cylinders.

Code of Federal Regulations, 2013 CFR

2013-10-01

... by spinning process not permitted. (b) Steel. The limiting chemical composition of steel authorized... equipment and processes adequate to ensure that each cylinder produced conforms to the requirements of this... welding or by threads. If threads are used they must comply with the following: (i) Threads must be clean...

49 CFR 178.36 - Specification 3A and 3AX seamless steel cylinders.

Code of Federal Regulations, 2013 CFR

2013-10-01

.... Cylinders must be manufactured using equipment and processes adequate to ensure that each cylinder produced... openings. Threads are required on openings. (1) Threads must be clean cut, even, without checks, and to gauge. (2) Taper threads, when used, must be of length not less than as specified for American Standard...

16 CFR 1512.4 - Mechanical requirements.

Code of Federal Regulations, 2011 CFR

2011-01-01

... burrs of spurs caused during the shearing process. (c) Integrity. There shall be no visible fracture of... quality thread form is specified in Handbook H28, “Screw Thread Standards for Federal Service,” 1 issued..., 262, and 263, “General Purpose Screw Threads.” 2 1 Copies may be obtained from: Superintendent of...

16 CFR 1512.4 - Mechanical requirements.

Code of Federal Regulations, 2014 CFR

2014-01-01

... of edges, or any burrs or spurs caused during the shearing process. (c) Integrity. There shall be no.... Recommended quality thread form is specified in Handbook H28, “Screw Thread Standards for Federal Service,” 1..., 262, and 263, “General Purpose Screw Threads.” 2 1 Copies may be obtained from: Superintendent of...

75 FR 7244 - Narrow Woven Ribbons with Woven Selvedge from the People's Republic of China: Preliminary...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-18

.... (``Guangzhou Complacent''); Ningbo Huarui Import & Export Co., Ltd.; Ningbo Jinfeng Thread & Ribbon Co. Ltd... limited to nylon, polyester, rayon, polypropylene, and polyethylene teraphthalate), metal threads and/or... 13) or rubber thread; (4) narrow woven ribbons of a kind used for the manufacture of typewriter or...

49 CFR 178.36 - Specification 3A and 3AX seamless steel cylinders.

Code of Federal Regulations, 2014 CFR

2014-10-01

.... Cylinders must be manufactured using equipment and processes adequate to ensure that each cylinder produced... openings. Threads are required on openings. (1) Threads must be clean cut, even, without checks, and to gauge. (2) Taper threads, when used, must be of length not less than as specified for American Standard...