Comparison between ray-tracing and physical optics for the computation of light absorption in capillaries--the influence of diffraction and interference.

PubMed

Qin, Yuan; Michalowski, Andreas; Weber, Rudolf; Yang, Sen; Graf, Thomas; Ni, Xiaowu

2012-11-19

Ray-tracing is the commonly used technique to calculate the absorption of light in laser deep-penetration welding or drilling. Since new lasers with high brilliance enable small capillaries with high aspect ratios, diffraction might become important. To examine the applicability of the ray-tracing method, we studied the total absorptance and the absorbed intensity of polarized beams in several capillary geometries. The ray-tracing results are compared with more sophisticated simulations based on physical optics. The comparison shows that the simple ray-tracing is applicable to calculate the total absorptance in triangular grooves and in conical capillaries but not in rectangular grooves. To calculate the distribution of the absorbed intensity ray-tracing fails due to the neglected interference, diffraction, and the effects of beam propagation in the capillaries with sub-wavelength diameter. If diffraction is avoided e.g. with beams smaller than the entrance pupil of the capillary or with very shallow capillaries, the distribution of the absorbed intensity calculated by ray-tracing corresponds to the local average of the interference pattern found by physical optics.

Triangular-shaped landforms reveal subglacial drainage routes in SW Finland

NASA Astrophysics Data System (ADS)

Mäkinen, J.; Kajuutti, K.; Palmu, J.-P.; Ojala, A.; Ahokangas, E.

2017-05-01

The aim of this study is to present the first evidence of triangular-shaped till landforms and related erosional features indicative of subglacial drainage within the ice stream bed of the Scandinavian ice sheet in Finland. Previously unidentified grouped patterns of Quaternary deposits with triangular landforms can be recognized from LiDAR-based DEMs. The triangular landforms occur as segments within geomorphologically distinguishable routes that are associated with eskers. The morphological and sedimentological characteristics as well as the distribution of the triangular landforms are interpreted to involve the creep of saturated deforming till, flow and pressure fluctuations of subglacial meltwater associated with meltwater erosion. There are no existing models for the formation of this kind of large-scale drainage systems, but we claim that they represent an efficient drainage system for subglacial meltwater transfer under high pressure conditions. Our hypothesis is that the routed, large-scale subglacial drainage systems described herein form a continuum between channelized (eskers) and more widely spread small-scale distributed subglacial drainage. Moreover, the transition from the conduit dominated drainage to triangular-shaped subglacial landforms takes place about 50-60 km from the ice margin. We provide an important contribution towards a more realistic representation of ice sheet hydrological drainage systems that could be used to improve paleoglaciological models and to simulate likely responses of ice sheets to increased meltwater production.

Evolution of triangular topographic facets along active normal faults

NASA Astrophysics Data System (ADS)

Balogun, A.; Dawers, N. H.; Gasparini, N. M.; Giachetta, E.

2011-12-01

Triangular shaped facets, which are generally formed by the erosion of fault - bounded mountain ranges, are arguably one of the most prominent geomorphic features on active normal fault scarps. Some previous studies of triangular facet development have suggested that facet size and slope exhibit a strong linear dependency on fault slip rate, thus linking their growth directly to the kinematics of fault initiation and linkage. Other studies, however, generally conclude that there is no variation in triangular facet geometry (height and slope) with fault slip rate. The landscape of the northeastern Basin and Range Province of the western United States provides an opportunity for addressing this problem. This is due to the presence of well developed triangular facets along active normal faults, as well as spatial variations in fault scale and slip rate. In addition, the Holocene climatic record for this region suggests a dominant tectonic regime, as the faulted landscape shows little evidence of precipitation gradients associated with tectonic uplift. Using GIS-based analyses of USGS 30 m digital elevation data (DEMs) for east - central Idaho and southwestern Montana, we analyze triangular facet geometries along fault systems of varying number of constituent segments. This approach allows us to link these geometries with established patterns of along - strike slip rate variation. For this study, we consider major watersheds to include only catchments with upstream and downstream boundaries extending from the drainage divide to the mapped fault trace, respectively. In order to maintain consistency in the selection criteria for the analyzed triangular facets, only facets bounded on opposite sides by major watersheds were considered. Our preliminary observations reflect a general along - strike increase in the surface area, average slope, and relief of triangular facets from the tips of the fault towards the center. We attribute anomalies in the along - strike geometric measurements of the triangular facets to represent possible locations of fault segment linkage associated with normal fault evolution.

Seasonal control skylight glazing panel with passive solar energy switching

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

Miller, J.V.

1983-10-25

A substantially transparent one-piece glazing panel is provided for generally horizontal mounting in a skylight. The panel is comprised of an repeated pattern of two alternating and contiguous linear optical elements; a first optical element being an upstanding generally right-triangular linear prism, and the second optical element being an upward-facing plano-cylindrical lens in which the planar surface is reflectively opaque and is generally in the same plane as the base of the triangular prism.

Experiments with Patterns

ERIC Educational Resources Information Center

de Mestre, Neville

2008-01-01

This article presents a hands-on experiment that covers many areas of high school mathematics. Included are the notions of patterns, proof, triangular numbers and various aspects of problem solving. The problem involves the arrangements of a school of fish using split peas or buttons to represent the fish. (Contains 4 figures.)

Cooperative Security in the Pacific Basin. The 1988 Pacific Symposium,

DTIC Science & Technology

1990-01-01

show the same pattern which Taiwan established and Singapore is following closely. Among the four Asian NICs Hong Kong led the pattern early, followed...government, have become a driving force for the tri- angular trade pattern among the United States, Japan, and the East Asian countries. JAPANESE DIRECT...Division of roles between the United States and Japan in East Asia has unintentionally effected a triangular trade pattern among the United States, Japan

Designing Tripodal and Triangular Gadolinium Oxide Nanoplates and Self-Assembled Nanofibrils as Potential Multimodal Bioimaging Probes

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

Paik, T; Gordon, TR; Prantner, AM

2013-03-01

Here, we report the shape-controlled synthesis of tripodal and triangular gadolinium oxide (Gd2O3) nanoplates. In the presence of lithium ions, the shape of the nanocrystals is readily controlled by tailoring reaction parameters such as temperature and time. We observe that the morphology transforms from an initial tripodal shape to a triangular shape with increasing reaction time or elevated temperatures. Highly uniform Gd2O3 nanoplates are self-assembled into nanofibril-like liquid-crystalline superlattices with long-range orientational and positional order. In addition, shape-directed self-assemblies are investigated by tailoring the aspect ratio of the arms of the Gd2O3 nanoplates. Due to a strong paramagnetic response, Gd2O3more » nanocrystals are excellent candidates for MRI contrast agents and also can be doped with rare-earth ions to form nanophosphors, pointing to their potential in multimodal imaging. In this work, we investigate the MR relaxometry at high magnetic fields (9,4 and 14.1 T) and the optical properties including near-IR to visible upconversion luminescence and X-ray excited optical luminescence of doped Gd2O3 nanoplates. The complex shape of Gd2O3 nanoplates, coupled with their magnetic properties and their ability to phosphoresce under NIR or X-ray excitation which penetrate deep into tissue, makes these nanoplates a promising platform for multimodal imaging in biomedical applications.« less

Laterally Placed CDRA with Triangular Notches for Ultra Wideband Applications

NASA Astrophysics Data System (ADS)

Sankaranarayanan, Dileep; Venkata Kiran, Duggirala; Mukherjee, Biswajeet

2017-12-01

In this paper, a Coaxial probe-fed Laterally placed Cylindrical Dielectric Resonator Antenna (LCDRA) with symmetrical triangular notches is presented. The lateral surface of the Cylindrical Dielectric Resonator Antenna (CDRA) is kept on the ground plane with its longitudinal axis parallel to the ground plane. LCDRA has a lower resonant frequency than the CDRA and it offers considerably wider impedance bandwidth than CDRA. Finally, two symmetrical triangular notches are introduced on the two edges of LCDRA which is perpendicular to the axis to further improve the impedance bandwidth. The proposed antenna offers a wide impedance bandwidth (S_{11} <-10 dB) of 76.7 % (4.5-10.1 GHz). The radiation pattern of the proposed antenna is stable and broadside throughout the impedance bandwidth of operation. The prototype of the proposed antenna is fabricated and measured results are found to be in good agreement with the simulated one.

Flipping Triangles!

ERIC Educational Resources Information Center

Zucker, Marc

2009-01-01

We introduce a simple game made up of a board of coins on a triangular lattice. We then study the possibility of turning the board from one pattern of heads and tails to some other pattern. Given that a solution exists we find a precise answer to the number of solutions possible. We then generalize this to more complex boards with coins of many…

Four-Element Composite Triangular Dielectric Resonator Antenna Using Li2O-1.94MgO-0.02Al2O3-P2O5 Ceramic for Wideband Applications

NASA Astrophysics Data System (ADS)

Kumari, Preeti; Tripathi, Pankaj; Sahu, B.; Singh, S. P.; Kumar, Devendra

2018-05-01

A simulation and fabrication study of a coaxial probe-fed four-element composite triangular dielectric resonator antenna (TDRA) using low loss Li2O-1.94MgO-0.02Al2O3-P2O5 (LMAP) ceramic and Teflon. LMAP ceramic was carried out and the ceramic was synthesized using a solid-state sintering route. The phase, microstructure and microwave dielectric properties of LMAP were investigated using x-ray diffraction pattern, scanning electron microscopy and a network analyzer. A coaxial probe-fed four-element composite TDRA was designed and fabricated using LMAP as one section of each composite element of the proposed antenna. Each triangular element of the proposed dielectric resonator antenna (DRA) consists of two sections of different dielectric constant materials. The inner triangular section touching the coaxial probe at one of its corners is made of the LMAP ceramic (ɛ r = 6.2) while othe uter section is made of Teflon (ɛ r = 2.1). Four triangular DRA elements are excited bya centrally located 50-Ω coaxial probe. The parametric study of the proposed antenna was performed through simulation using Ansys High Frequency Structure Simulator software by varying the dimensions and dielectric constants of both sections of each triangular element of the TDRA to optimize the results for obtaining a wideband antenna. The simulated resonant frequency of 9.30 GHz with a percentage bandwidth of 61.65% for the proposed antenna is obtained within its operating frequency range of 7.82-14.8 GHz. Monopole-like radiation patterns with low cross-polarization levels and a peak gain of 5.63 dB are obtained for the proposed antenna through simulation. The antenna prototype having optimized dimensions has also been fabricated. The experimental resonant frequency of 9.10 GHz with a percentage bandwidth of 66.09% is obtained within its operating frequency range of 7.70-15.30 GHz. It is found that the simulation results for the proposed antenna are in close agreement with the measured data. The proposed antenna can potentially be used in broadcast base stations, radar and satellite communications.

Batchwise growth of silica cone patterns via self-assembly of aligned nanowires.

PubMed

Luo, Shudong; Zhou, Weiya; Chu, Weiguo; Shen, Jun; Zhang, Zengxing; Liu, Lifeng; Liu, Dongfang; Xiang, Yanjuan; Ma, Wenjun; Xie, Sishen

2007-03-01

Silica-cone patterns self-assembled from well-aligned nanowires are synthesized using gallium droplets as the catalyst and silicon wafers as the silicon source. The cones form a triangular pattern array radially on almost the whole surface of the molten Ga ball. Detailed field-emission scanning electron microscopy (SEM) analysis shows that the cone-pattern pieces frequently slide off and are detached from the molten Ga ball surface, which leads to the exposure of the catalyst surface and the growth of a new batch of silicon oxide nanowires as well as the cone patterns. The processes of growth and detachment alternate, giving rise to the formation of a volcano-like or a flower-like structure with bulk-quantity pieces of cone patterns piled up around the Ga ball. Consequently, the cone-patterned layer grows batch by batch until the reaction is terminated. Different to the conventional metal-catalyzed growth model, the batch-by-batch growth of the triangular cone patterns proceeds on the molten Ga balls via alternate growth on and detachment from the catalyst surface of the patterns; the Ga droplet can be used continuously and circularly as an effective catalyst for the growth of amorphous SiO(x) nanowires during the whole growth period. The intriguing batchwise growth phenomena may enrich our understanding of the vapour-liquid-solid (VLS) growth mechanism for the catalyst growth of nanowires or other nanostructures and may offer a different way of self-assembling novel silica nanostructures.

Current density distributions and sputter marks in electron cyclotron resonance ion sources

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

Panitzsch, Lauri; Peleikis, Thies; Boettcher, Stephan

2013-01-15

Most electron cyclotron resonance ion sources use hexapolar magnetic fields for the radial confinement of the plasma. The geometry of this magnetic structure is then-induced by charged particles-mapped onto the inner side of the plasma electrode via sputtering and deposition. The resulting structures usually show two different patterns: a sharp triangular one in the central region which in some cases is even sputtered deep into the material (referred to as thin groove or sharp structure), and a blurred but still triangular-like one in the surroundings (referred to as broad halo). Therefore, both patterns seem to have different sources. To investigatemore » their origins we replaced the standard plasma electrode by a custom-built plasma electrode acting as a planar, multi-segment current-detector. For different biased disc voltages, detector positions, and source biases (referred to the detector) we measured the electrical current density distributions in the plane of the plasma electrode. The results show a strong and sharply confined electron population with triangular shape surrounded by less intense and spatially less confined ions. Observed sputter- and deposition marks are related to the analysis of the results. Our measurements suggest that the two different patterns (thin and broad) indeed originate from different particle populations. The thin structures seem to be caused by the hot electron population while the broad marks seem to stem from the medium to highly charged ions. In this paper we present our measurements together with theoretical considerations and substantiate the conclusions drawn above. The validity of these results is also discussed.« less

Linear beam raster magnet driver based on H-bridge technique

DOEpatents

Sinkine, Nikolai I.; Yan, Chen; Apeldoorn, Cornelis; Dail, Jeffrey Glenn; Wojcik, Randolph Frank; Gunning, William

2006-06-06

An improved raster magnet driver for a linear particle beam is based on an H-bridge technique. Four branches of power HEXFETs form a two-by-two switch. Switching the HEXFETs in a predetermined order and at the right frequency produces a triangular current waveform. An H-bridge controller controls switching sequence and timing. The magnetic field of the coil follows the shape of the waveform and thus steers the beam using a triangular rather than a sinusoidal waveform. The system produces a raster pattern having a highly uniform raster density distribution, eliminates target heating from non-uniform raster density distributions, and produces higher levels of beam current.

Prediction of penetration rate of rotary-percussive drilling using artificial neural networks - a case study / Prognozowanie postępu wiercenia przy użyciu wiertła udarowo-obrotowego przy wykorzystaniu sztucznych sieci neuronowych - studium przypadku

NASA Astrophysics Data System (ADS)

Aalizad, Seyed Ali; Rashidinejad, Farshad

2012-12-01

Penetration rate in rocks is one of the most important parameters of determination of drilling economics. Total drilling costs can be determined by predicting the penetration rate and utilized for mine planning. The factors which affect penetration rate are exceedingly numerous and certainly are not completely understood. For the prediction of penetration rate in rotary-percussive drilling, four types of rocks in Sangan mine have been chosen. Sangan is situated in Khorasan-Razavi province in Northeastern Iran. The selected parameters affect penetration rate is divided in three categories: rock properties, drilling condition and drilling pattern. The rock properties are: density, rock quality designation (RQD), uni-axial compressive strength, Brazilian tensile strength, porosity, Mohs hardness, Young modulus, P-wave velocity. Drilling condition parameters are: percussion, rotation, feed (thrust load) and flushing pressure; and parameters for drilling pattern are: blasthole diameter and length. Rock properties were determined in the laboratory, and drilling condition and drilling pattern were determined in the field. For create a correlation between penetration rate and rock properties, drilling condition and drilling pattern, artificial neural networks (ANN) were used. For this purpose, 102 blastholes were observed and drilling condition, drilling pattern and time of drilling in each blasthole were recorded. To obtain a correlation between this data and prediction of penetration rate, MATLAB software was used. To train the pattern of ANN, 77 data has been used and 25 of them found for testing the pattern. Performance of ANN models was assessed through the root mean square error (RMSE) and correlation coefficient (R2). For optimized model (14-14-10-1) RMSE and R2 is 0.1865 and 86%, respectively, and its sensitivity analysis showed that there is a strong correlation between penetration rate and RQD, rotation and blasthole diameter. High correlation coefficient and low root mean square error of these models showed that the ANN is a suitable tool for penetration rate prediction.

3D animation of facial plastic surgery based on computer graphics

NASA Astrophysics Data System (ADS)

Zhang, Zonghua; Zhao, Yan

2013-12-01

More and more people, especial women, are getting desired to be more beautiful than ever. To some extent, it becomes true because the plastic surgery of face was capable in the early 20th and even earlier as doctors just dealing with war injures of face. However, the effect of post-operation is not always satisfying since no animation could be seen by the patients beforehand. In this paper, by combining plastic surgery of face and computer graphics, a novel method of simulated appearance of post-operation will be given to demonstrate the modified face from different viewpoints. The 3D human face data are obtained by using 3D fringe pattern imaging systems and CT imaging systems and then converted into STL (STereo Lithography) file format. STL file is made up of small 3D triangular primitives. The triangular mesh can be reconstructed by using hash function. Top triangular meshes in depth out of numbers of triangles must be picked up by ray-casting technique. Mesh deformation is based on the front triangular mesh in the process of simulation, which deforms interest area instead of control points. Experiments on face model show that the proposed 3D animation facial plastic surgery can effectively demonstrate the simulated appearance of post-operation.

Linking species abundance distributions in numerical abundance and biomass through simple assumptions about community structure.

PubMed

Henderson, Peter A; Magurran, Anne E

2010-05-22

Species abundance distributions (SADs) are widely used as a tool for summarizing ecological communities but may have different shapes, depending on the currency used to measure species importance. We develop a simple plotting method that links SADs in the alternative currencies of numerical abundance and biomass and is underpinned by testable predictions about how organisms occupy physical space. When log numerical abundance is plotted against log biomass, the species lie within an approximately triangular region. Simple energetic and sampling constraints explain the triangular form. The dispersion of species within this triangle is the key to understanding why SADs of numerical abundance and biomass can differ. Given regular or random species dispersion, we can predict the shape of the SAD for both currencies under a variety of sampling regimes. We argue that this dispersion pattern will lie between regular and random for the following reasons. First, regular dispersion patterns will result if communities are comprised groups of organisms that use different components of the physical space (e.g. open water, the sea bed surface or rock crevices in a marine fish assemblage), and if the abundance of species in each of these spatial guilds is linked to the way individuals of varying size use the habitat. Second, temporal variation in abundance and sampling error will tend to randomize this regular pattern. Data from two intensively studied marine ecosystems offer empirical support for these predictions. Our approach also has application in environmental monitoring and the recognition of anthropogenic disturbance, which may change the shape of the triangular region by, for example, the loss of large body size top predators that occur at low abundance.

The distribution patterns of COMP and matrilin-3 in septal, alar and triangular cartilages of the human nose.

PubMed

Wiggenhauser, Paul Severin; Schwarz, Silke; Rotter, Nicole

2018-05-02

The biomechanical characteristics of septal cartilage depend strongly on the distinct extracellular matrix of cartilage tissue; therefore, it is essential that the components of this matrix are identified and understood. Cartilage oligomeric matrix protein (COMP) and matrilin-3 are localised in articular cartilage. This study was the first to examine all subtypes of mature human nasal cartilages (alar, triangular and septal) with specific attention to the distribution of COMP and matrilin-3. Three whole fresh-frozen noses from human donors were dissected, and exemplary biopsies were examined using histochemical staining (haematoxylin and eosin and Alcian blue) and immunohistochemistry (collagen II, COMP and matrilin-3). The following three zones within the nasal cartilage were identified: superficial, intermediate and central. COMP was detected as highest in the intermediate zones in all three subtypes of nasal cartilage, whereas matrilin-3 was detected with pericellular deposition mainly within septal cartilage predominantly in the superficial zones. The distinct staining patterns of COMP and matrilin-3 underscore the different functional roles of both proteins in nasal cartilage. According to the literature, COMP might be involved with collagen II in the formation of networks, whereas matrilin-3 is reported to prevent ossification or regulate mechanosensitivity. The predominant staining observed in septal cartilage suggests matrilin-3's modulatory role because of its presence in the osteochondral junctional zone and given that the biomechanical load in septal cartilage is different from that in alar or triangular cartilage. In conclusion, COMP and matrilin-3 were detected in mature human nasal cartilage but displayed different staining patterns that might be explained by the functional roles of the respective matrix protein; however, further research is necessary to identify and define the functional aspects of this morphological difference.

Linking species abundance distributions in numerical abundance and biomass through simple assumptions about community structure

PubMed Central

Henderson, Peter A.; Magurran, Anne E.

2010-01-01

Species abundance distributions (SADs) are widely used as a tool for summarizing ecological communities but may have different shapes, depending on the currency used to measure species importance. We develop a simple plotting method that links SADs in the alternative currencies of numerical abundance and biomass and is underpinned by testable predictions about how organisms occupy physical space. When log numerical abundance is plotted against log biomass, the species lie within an approximately triangular region. Simple energetic and sampling constraints explain the triangular form. The dispersion of species within this triangle is the key to understanding why SADs of numerical abundance and biomass can differ. Given regular or random species dispersion, we can predict the shape of the SAD for both currencies under a variety of sampling regimes. We argue that this dispersion pattern will lie between regular and random for the following reasons. First, regular dispersion patterns will result if communities are comprised groups of organisms that use different components of the physical space (e.g. open water, the sea bed surface or rock crevices in a marine fish assemblage), and if the abundance of species in each of these spatial guilds is linked to the way individuals of varying size use the habitat. Second, temporal variation in abundance and sampling error will tend to randomize this regular pattern. Data from two intensively studied marine ecosystems offer empirical support for these predictions. Our approach also has application in environmental monitoring and the recognition of anthropogenic disturbance, which may change the shape of the triangular region by, for example, the loss of large body size top predators that occur at low abundance. PMID:20071388

Algorithms for solving large sparse systems of simultaneous linear equations on vector processors

NASA Technical Reports Server (NTRS)

David, R. E.

1984-01-01

Very efficient algorithms for solving large sparse systems of simultaneous linear equations have been developed for serial processing computers. These involve a reordering of matrix rows and columns in order to obtain a near triangular pattern of nonzero elements. Then an LU factorization is developed to represent the matrix inverse in terms of a sequence of elementary Gaussian eliminations, or pivots. In this paper it is shown how these algorithms are adapted for efficient implementation on vector processors. Results obtained on the CYBER 200 Model 205 are presented for a series of large test problems which show the comparative advantages of the triangularization and vector processing algorithms.

Emittance Measurements for a Thin Liquid Sheet Flow

NASA Technical Reports Server (NTRS)

Englehart, Amy N.; McConley, Marc W.; Chubb, Donald L.

1996-01-01

The Liquid Sheet Radiator (LSR) is an external flow radiator that uses a triangular-shaped flowing liquid sheet as the radiating surface. It has potentially much lower mass than solid wall radiators such as pumped loop and heat pipe radiators, along with being nearly immune to micrometeoroid penetration. The LSR has an added advantage of simplicity. Surface tension causes a thin (100-300 microns) liquid sheet to coalesce to a point, causing the sheet flow to have a triangular shape. Such a triangular sheet is desirable since it allows for simple collection of the flow at a single point. A major problem for all external flow radiators is the requirement that the working fluid be of very low (approx. 10(sup -8) torr) vapor pressure to keep evaporative losses low. As a result, working fluids are limited to certain oils (such as used in diffusion pumps) for low temperatures (300-400 K) and liquid metals for higher temperatures. Previous research on the LSR has been directed at understanding the fluid mechanics of thin sheet flows and assessing the stability of such flows, especially with regard to the formation of holes in the sheet. Taylor studied extensively the stability of thin liquid sheets both theoretically and experimentally. He showed that thin sheets in a vacuum are stable. The latest research has been directed at determining the emittance of thin sheet flows. The emittance was calculated from spectral transmittance data for the Dow Corning 705 silicone oil. By experimentally setting up a sheet flow, the emittance was also determined as a function of measurable quantities, most importantly, the temperature drop between the top of the sheet and the temperature at the coalescence point of the sheet. Temperature fluctuations upstream of the liquid sheet were a potential problem in the analysis and were investigated.

Patterns of triangular fibrocartilage complex (TFCC) injury associated with severely dorsally displaced extra-articular distal radius fractures.

PubMed

Scheer, Johan H; Adolfsson, Lars E

2012-06-01

The aim of the study was to examine triangular fibrocartilage (TFCC) injury patterns associated with unstable, extra-articular dorsally displaced distal radius fractures. Twenty adult patients with an Arbeitsgemeinschaft für Osteosynthesefragen (AO), type A2 or A3, distal radius fracture with an initial dorsal angulation greater than 20° were included. Nine had a tip fracture (distal to the base) of the ulnar styloid and 11 had no such fracture. They were all openly explored from an ulnopalmar approach and TFCC injuries were documented. Eleven patients also underwent arthroscopy and intra-articular pathology was recorded. All patients had TFCC lesions of varying severity, having an extensor carpi ulnaris subsheath avulsion in common. Eighteen out of 20 also displayed deep foveal radioulnar ligament lesions, with decreasingly dorsal fibres remaining. The extent of this foveal injury could not be appreciated by radiocarpal arthroscopy. Severe displacement of an extra-articular radius fracture suggests an ulnar-sided ligament injury to the TFCC. The observed lesions concur with findings in a previous cadaver study. The lesions follow a distinct pattern affecting both radioulnar as well as ulnocarpal stabilisers. Copyright © 2012 Elsevier Ltd. All rights reserved.

Limitation of optical properties through porous silicon photonic crystals influenced by porosity and lattice dynamic

NASA Astrophysics Data System (ADS)

Amedome Min-Dianey, Kossi Aniya; Zhang, Hao-Chun; M'Bouana, Noé Landry Privace; Kougblenou, Komi; Xia, Xinlin

2018-01-01

Finite differential time domain (FDTD) tools were applied to simulate the optical properties characteristics' through square and triangular lattices of porous silicon (pSi) photonic crystals (PhCs); which consisted of periodical patterns of circular air holes built into the pSi material. This was used to investigate the influence of porosity and lattice dynamic on the reflection, transmission and absorption characteristics through unit cell pSi PhC in the visible wavelength domain (400 nm - 700 nm). The numerical simulation was achieved using FDTD Lumerical solutions with periodic boundary conditions (PBC) and perfectly matched layers (PML) as the appropriate boundary conditions. The results revealed that the limitation of optical properties is dependent on porosity and the lattice dynamic in pSi PhC. This was presented by the trend; the higher the reflection the higher the porosity and a decrease in porosity led to an increase in absorption in both lattice considerations. It was discovered that attaining optimum properties for triangular lattice will entail considering porosities less than 50% and hole radius r to the lattice constant a ratio (r / a) above 0.3 for the absorption characteristic and below 0.3 for the transmission characteristic. Triangular lattice can be adapted to improve the optical pattern through the PhC. In addition, the optimisation of these properties through pSi PhCs was achieved by controlling porosity and the ratio r / a .

Three‐dimensional myocardial scarring along myofibers after coronary ischemia–reperfusion revealed by computerized images of histological assays

PubMed Central

Katz, Monica Y.; Kusakari, Yoichiro; Aoyagi, Hiroko; Higa, Jason K.; Xiao, Chun‐Yang; Abdelkarim, Ahmed Z.; Marh, Karra; Aoyagi, Toshinori; Rosenzweig, Anthony; Lozanoff, Scott; Matsui, Takashi

2014-01-01

Abstract Adverse left ventricular (LV) remodeling after acute myocardial infarction is characterized by LV dilatation and development of a fibrotic scar, and is a critical factor for the prognosis of subsequent development of heart failure. Although myofiber organization is recognized as being important for preserving physiological cardiac function and structure, the anatomical features of injured myofibers during LV remodeling have not been fully defined. In a mouse model of ischemia–reperfusion (I/R) injury induced by left anterior descending coronary artery ligation, our previous histological assays demonstrated that broad fibrotic scarring extended from the initial infarct zone to the remote zone, and was clearly demarcated along midcircumferential myofibers. Additionally, no fibrosis was observed in longitudinal myofibers in the subendocardium and subepicardium. However, a histological analysis of tissue sections does not adequately indicate myofiber injury distribution throughout the entire heart. To address this, we investigated patterns of scar formation along myofibers using three‐dimensional (3D) images obtained from multiple tissue sections from mouse hearts subjected to I/R injury. The fibrotic scar area observed in the 3D images was consistent with the distribution of the midcircumferential myofibers. At the apex, the scar formation tracked along the myofibers in an incomplete C‐shaped ring that converged to a triangular shape toward the end. Our findings suggest that myocyte injury after transient coronary ligation extends along myofibers, rather than following the path of coronary arteries penetrating the myocardium. The injury pattern observed along myofibers after I/R injury could be used to predict prognoses for patients with myocardial infarction. PMID:25347856

(e, 2e) simple ionization of {{\\rm{H}}}_{3}^{+} by fast electron impact: use of triangular three-center continuum and bound state wave functions

NASA Astrophysics Data System (ADS)

Obeid, S.; Chuluunbaatar, O.; Joulakian, B. B.

2017-07-01

The variation of the multiply differential cross section of the (e, 2e) simple ionization of {{{H}}}3+, with the incident and ejection energy values, as well as the directions of the ejected and scattered electrons, is studied. The calculations have been performed in the frame of the perturbative first Born procedure, which has required the development of equilateral triangular three center bound and continuum state wave functions. The results explore the optimal conditions and the particularities of the triangular targets, such as the appearance of interference patterns in the variation of the four fold differential cross section (FDCS) with the scattering angle for a fixed orientation of the molecule. The comparison between the results obtained by two H3 + ground wave functions, with and without a correlation term r 12, shows that the effect of correlation on the magnitude of the triple differential cross section is not large, but it produces some modification in the structure of the FDCS.

Large area multi-channel plasmonic absorber based on the touching triangular dimers fabricated by angle controlled colloidal nanolithography

NASA Astrophysics Data System (ADS)

Hamidi, S. M.; Behjati, S.

2018-02-01

Here we introduce large area plasmonic touching triangular dimers by angle controlled colloidal nanolithography to use them as an efficient multi channel absorber and also high figure of merit sensors. For this purpose, we coated gold thin films onto nanometric and also micrometric polystyrene hexagonal closed packed masks in different deposition angles and also diverse substrate polar angles. Our prepared samples, after remove masks, show large area touching triangular pattern with different inter particle distances in greater polar angles. To get more sense about optical response of the samples such as transmittance and also electric field distribution, we use finite difference time domain method in simulation part. The transmittance plot shows one narrow or multi-channel adjustable deep depend on inter-particle distances which can be controlled by azimuthally angle in nano lithography process. Also, due to the isoelliptical points in the transmittance spectra; we can see the bright and dark plasmon modes coupling and thus the Fano like resonance takes place in the optical spectral region which is very useful for refractive index measurement.

Radiography of gynecomastia and other disorders of the male breast.

PubMed

Michels, L G; Gold, R H; Arndt, R D

1977-01-01

Mammographic features of 22 pathologically proved cases reflecting disorders of the male breast are described. Two patterns of gynecomastia were observed: a dendritic pattern seen in association with breast enlargement for 6 months or more, and a more florid triangular pattern, seen in association with breast enlargement of recent onset. Male breast carcinoma may be distinguished from gynecomastia by its eccentric location, spiculation, and, in some cases, calcification or involvement of the skin and nipple. Benign conditions simulating carcinoma included a case of drug-induced gynecomastia and a case of inflamed inclusion cyst.

Triangular Graphene Grain Growth on Cube-Textured Cu Substrates

DTIC Science & Technology

2011-01-01

rate of CuOx decreases with decreasing H 2 partial pressure. [ 32 ] According to the Cu-O phase diagram, [ 33 ] the eutectic temperature of Cu-CuO and...accelerating voltage of 2 KeV. The electron backscatter diffraction patterns (EBSP) were used to examine recrystallization and grain orientation of

Copper drift in high-dielectric-constant tantalum oxide thin films under bias temperature stress

NASA Astrophysics Data System (ADS)

Jain, Pushkar; Juneja, Jasbir S.; Mallikarjunan, A.; Rymaszewski, E. J.; Lu, T.-M.

2006-04-01

The use of high-dielectric-constant (high-κ) materials for embedded capacitors is becoming increasingly important. Tantalum oxide (Ta2O5) is a prominent candidate as a high-κ material for embedded capacitor use. Metal drift in Ta2O5 (κ˜25) was investigated by bias temperature stress and triangular voltage sweep testing techniques on metal/Ta2O5/SiO2/Si structures. At a temperature of 300°C and 0.75MV/cm bias conditions, Al, Ta, and Ti do not diffuse in Ta2O5, but Cu clearly showed a drift. The Cu drift is attributed to the lack of a stable Cu oxide which can limit Cu ion generation and penetration.

Polyethylene wear in Oxford unicompartmental knee replacement: a retrieval study of 47 bearings.

PubMed

Kendrick, B J L; Longino, D; Pandit, H; Svard, U; Gill, H S; Dodd, C A F; Murray, D W; Price, A J

2010-03-01

The Oxford Unicompartmental Knee replacement (UKR) was introduced as a design to reduce polyethylene wear. There has been one previous retrieval study involving this implant, which reported very low rates of wear in some specimens but abnormal patterns of wear in others. There has been no further investigation of these abnormal patterns. The bearings were retrieved from 47 patients who had received a medial Oxford UKR for anteromedial osteoarthritis of the knee. None had been studied previously. The mean time to revision was 8.4 years (sd 4.1), with 20 having been implanted for over ten years. The macroscopic pattern of polyethylene wear and the linear penetration were recorded for each bearing. The mean rate of linear penetration was 0.07 mm/year. The patterns of wear fell into three categories, each with a different rate of linear penetration; 1) no abnormal macroscopic wear and a normal articular surface, n = 16 (linear penetration rate = 0.01 mm/year); 2) abnormal macroscopic wear and normal articular surfaces with extra-articular impingement, n = 16 (linear penetration rate = 0.05 mm/year); 3) abnormal macroscopic wear and abnormal articular surfaces with intra-articular impingement +/- signs of non-congruous articulation, n = 15 (linear penetration rate = 0.12 mm/year). The differences in linear penetration rate were statistically significant (p < 0.001). These results show that very low rates of polyethylene wear are possible if the device functions normally. However, if the bearing displays suboptimal function (extra-articular, intra-articular impingement or incongruous articulation) the rates of wear increase significantly.

Numerical investigation of the interaction between a planar shock wave with square and triangular bubbles containing different gases

NASA Astrophysics Data System (ADS)

Igra, Dan; Igra, Ozer

2018-05-01

The interaction between a planar shock wave and square and triangular bubbles containing either SF6, He, Ar, or CO2 is studied numerically. It is shown that, due to the existing large differences in the molecular weight, the specific heat ratio, and the acoustic impedance between these gases, different wave patterns and pressure distribution inside the bubbles are developed during the interaction process. In the case of heavy gases, the velocity of the shock wave propagating along the bubble inner surface is always less than that of the incident shock wave and higher than that of the transmitted shock wave. However, in the case of the light gas (He), the fastest one is the transmitted shock wave and the slowest one is the incident shock wave. The largest pressure jump is witnessed in the SF6 case, while the smallest pressure jump is seen in the helium case. There are also pronounced differences in the deformation of the investigated bubbles; while triangular bubbles filled with either Ar, CO2, or SF6 were deformed to a crescent shape, the helium bubble is deformed to a trapezoidal shape with three pairs of vortices emanating from its surface.

Revisiting the fear of snakes in children: the role of aposematic signalling.

PubMed

Souchet, Jérémie; Aubret, Fabien

2016-11-25

Why humans fear snakes is an old, yet unresolved debate. Its innate origin from evolutionary causes is debated against the powerful influence early experience, culture, media and religion may have on people's aversion to snakes. Here we show that the aversion to snakes in human beings may have been mistaken for an aversion to aposematic signals that are commonly displayed by snakes. A total of 635 children were asked to rate single item images as "nice" or "mean". Snakes, pets and smiley emoticon items were not rated as "mean" unless they displayed subtle aposematic signals in the form of triangular (rather than round) shapes. Another 722 children were shown images featuring two items and asked which item was "nice" and which item was "mean". This context dependent comparison triggered even sharper responses to aposematic signals. We hypothesise that early primates evolved an aversion for aposematic signals in the form of potentially harmful triangular shapes such as teeth, claws or spikes, not for snakes per se. Further, we hypothesise that this adaptation was in turn exploited by snakes in their anti-predatory threat display as a triangular head or dorsal zig-zag pattern, and is currently the basis for efficient international road-danger signalling.

Using Chebyshev polynomials and approximate inverse triangular factorizations for preconditioning the conjugate gradient method

NASA Astrophysics Data System (ADS)

Kaporin, I. E.

2012-02-01

In order to precondition a sparse symmetric positive definite matrix, its approximate inverse is examined, which is represented as the product of two sparse mutually adjoint triangular matrices. In this way, the solution of the corresponding system of linear algebraic equations (SLAE) by applying the preconditioned conjugate gradient method (CGM) is reduced to performing only elementary vector operations and calculating sparse matrix-vector products. A method for constructing the above preconditioner is described and analyzed. The triangular factor has a fixed sparsity pattern and is optimal in the sense that the preconditioned matrix has a minimum K-condition number. The use of polynomial preconditioning based on Chebyshev polynomials makes it possible to considerably reduce the amount of scalar product operations (at the cost of an insignificant increase in the total number of arithmetic operations). The possibility of an efficient massively parallel implementation of the resulting method for solving SLAEs is discussed. For a sequential version of this method, the results obtained by solving 56 test problems from the Florida sparse matrix collection (which are large-scale and ill-conditioned) are presented. These results show that the method is highly reliable and has low computational costs.

Tracking Characteristics of a Triangular-Aperture Mounted Optical Head Slider to Which a Polarized Violet Laser Source Is Applied

NASA Astrophysics Data System (ADS)

Ohkubo, Toshifumi; Park, Majung; Hirata, Masakazu; Oumi, Manabu; Nakajima, Kunio

In near-field optical recording, the combination of a triangular aperture and a polarized illuminating light is thought to be one of the most promising breakthroughs for improving both spatial resolution and signal-to-noise ratio. In light of this, we have already fabricated a triangular-aperture mounted optical head slider and demonstrated its superior performance while clarifying the influence of the polarization direction on the spatial resolution in the circumferential direction. When the polarization direction was perpendicular to the bottom side (which is parallel to the slider trailing edge) of the aperture, the highest spatial resolution and signal contrast were obtained, in spite of the usage of a fairly large aperture, indicating the presence of clear readout signal waveforms corresponding down to 100 nm line-and-space (L/S) patterns. In this study, we tried to experimentally clarify the influence of the polarization direction of the illuminating light on an aperture's field spread in the radial direction. In order to concretely evaluate the field spread, we prepared 1-mm-long linearly arranged (in the circumferential direction) L/S patterns on a metal-layered medium, and a piezo-electric actuator combined positioner. Intersecting the aperture at two portions of the tracks, directly acquired signal waveforms could be successfully transformed into the waveforms that would be obtained if the aperture had crossed the track at right angles. The field spreads in the radial direction were estimated to be approximately 250 nm when the polarization direction was perpendicular to the bottom side. In contrast, when the polarization direction was 45 degrees, the stationary field spread in the radial direction was estimated to be approximately 350 - 370 nm. It could be confirmed experimentally that both the highest spatial resolution in the circumferential direction and the smallest field spread in the radial direction were realized with the combination of the triangular aperture and the illuminating polarized light whose direction was perpendicular to the bottom side. Based on these results, the signal-to-noise ratio will be evaluated and discussed in the future with respect to the above-mentioned optimum aperture structure and conditions.

Pattern drilling exploration: Optimum pattern types and hole spacings when searching for elliptical shaped targets

USGS Publications Warehouse

Drew, L.J.

1979-01-01

In this study the selection of the optimum type of drilling pattern to be used when exploring for elliptical shaped targets is examined. The rhombic pattern is optimal when the targets are known to have a preferred orientation. Situations can also be found where a rectangular pattern is as efficient as the rhombic pattern. A triangular or square drilling pattern should be used when the orientations of the targets are unknown. The way in which the optimum hole spacing varies as a function of (1) the cost of drilling, (2) the value of the targets, (3) the shape of the targets, (4) the target occurrence probabilities was determined for several examples. Bayes' rule was used to show how target occurrence probabilities can be revised within a multistage pattern drilling scheme. ?? 1979 Plenum Publishing Corporation.

New similarity of triangular fuzzy number and its application.

PubMed

Zhang, Xixiang; Ma, Weimin; Chen, Liping

2014-01-01

The similarity of triangular fuzzy numbers is an important metric for application of it. There exist several approaches to measure similarity of triangular fuzzy numbers. However, some of them are opt to be large. To make the similarity well distributed, a new method SIAM (Shape's Indifferent Area and Midpoint) to measure triangular fuzzy number is put forward, which takes the shape's indifferent area and midpoint of two triangular fuzzy numbers into consideration. Comparison with other similarity measurements shows the effectiveness of the proposed method. Then, it is applied to collaborative filtering recommendation to measure users' similarity. A collaborative filtering case is used to illustrate users' similarity based on cloud model and triangular fuzzy number; the result indicates that users' similarity based on triangular fuzzy number can obtain better discrimination. Finally, a simulated collaborative filtering recommendation system is developed which uses cloud model and triangular fuzzy number to express users' comprehensive evaluation on items, and result shows that the accuracy of collaborative filtering recommendation based on triangular fuzzy number is higher.

Entanglement and magnetism in high-spin graphene nanodisks

NASA Astrophysics Data System (ADS)

Hagymási, I.; Legeza, Ö.

2018-01-01

We investigate the ground-state properties of triangular graphene nanoflakes with zigzag edge configurations. The description of zero-dimensional nanostructures requires accurate many-body techniques since the widely used density-functional theory with local density approximation or Hartree-Fock methods cannot handle the strong quantum fluctuations. Applying the unbiased density-matrix renormalization group algorithm we calculate the magnetization and entanglement patterns with high accuracy for different interaction strengths and compare them to the mean-field results. With the help of quantum information analysis and subsystem density matrices we reveal that the edges are strongly entangled with each other. We also address the effect of electron and hole doping and demonstrate that the magnetic properties of triangular nanoflakes can be controlled by an electric field, which reveals features of flat-band ferromagnetism. This may open up new avenues in graphene based spintronics.

CONTROL ROD

DOEpatents

Zinn, W.H.; Ross, H.V.

1958-11-18

A control rod is described for a nuclear reactor. In certaln reactor designs it becomes desirable to use a control rod having great width but relatively llttle thickness. This patent is addressed to such a need. The neutron absorbing material is inserted in a triangular tube, leaving volds between the circular insert and the corners of the triangular tube. The material is positioned within the tube by the use of dummy spacers to achleve the desired absorption pattern, then the ends of the tubes are sealed with suitable plugs. The tubes may be welded or soldered together to form two flat surfaces of any desired width, and covered with sheetmetal to protect the tubes from damage. This design provides a control member that will not distort under the action of outside forces or be ruptured by gases generated within the jacketed control member.

An algorithm for propagating the square-root covariance matrix in triangular form

NASA Technical Reports Server (NTRS)

Tapley, B. D.; Choe, C. Y.

1976-01-01

A method for propagating the square root of the state error covariance matrix in lower triangular form is described. The algorithm can be combined with any triangular square-root measurement update algorithm to obtain a triangular square-root sequential estimation algorithm. The triangular square-root algorithm compares favorably with the conventional sequential estimation algorithm with regard to computation time.

Nanoselective area growth of GaN by metalorganic vapor phase epitaxy on 4H-SiC using epitaxial graphene as a mask

NASA Astrophysics Data System (ADS)

Puybaret, Renaud; Patriarche, Gilles; Jordan, Matthew B.; Sundaram, Suresh; El Gmili, Youssef; Salvestrini, Jean-Paul; Voss, Paul L.; de Heer, Walt A.; Berger, Claire; Ougazzaden, Abdallah

2016-03-01

We report the growth of high-quality triangular GaN nanomesas, 30-nm thick, on the C-face of 4H-SiC using nanoselective area growth (NSAG) with patterned epitaxial graphene grown on SiC as an embedded mask. NSAG alleviates the problems of defects in heteroepitaxy, and the high mobility graphene film could readily provide the back low-dissipative electrode in GaN-based optoelectronic devices. A 5-8 graphene-layer film is first grown on the C-face of 4H-SiC by confinement-controlled sublimation of silicon carbide. Graphene is then patterned and arrays of 75-nm-wide openings are etched in graphene revealing the SiC substrate. A 30-nm-thick GaN is subsequently grown by metal organic vapor phase epitaxy. GaN nanomesas grow epitaxially with perfect selectivity on SiC, in the openings patterned through graphene. The up-or-down orientation of the mesas on SiC, their triangular faceting, and cross-sectional scanning transmission electron microscopy show that they are biphasic. The core is a zinc blende monocrystal surrounded with single-crystal wurtzite. The GaN crystalline nanomesas have no threading dislocations or V-pits. This NSAG process potentially leads to integration of high-quality III-nitrides on the wafer scalable epitaxial graphene/silicon carbide platform.

Nanoselective area growth of GaN by metalorganic vapor phase epitaxy on 4H-SiC using epitaxial graphene as a mask

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

Puybaret, Renaud; Jordan, Matthew B.; Voss, Paul L.

We report the growth of high-quality triangular GaN nanomesas, 30-nm thick, on the C-face of 4H-SiC using nanoselective area growth (NSAG) with patterned epitaxial graphene grown on SiC as an embedded mask. NSAG alleviates the problems of defects in heteroepitaxy, and the high mobility graphene film could readily provide the back low-dissipative electrode in GaN-based optoelectronic devices. A 5–8 graphene-layer film is first grown on the C-face of 4H-SiC by confinement-controlled sublimation of silicon carbide. Graphene is then patterned and arrays of 75-nm-wide openings are etched in graphene revealing the SiC substrate. A 30-nm-thick GaN is subsequently grown by metalmore » organic vapor phase epitaxy. GaN nanomesas grow epitaxially with perfect selectivity on SiC, in the openings patterned through graphene. The up-or-down orientation of the mesas on SiC, their triangular faceting, and cross-sectional scanning transmission electron microscopy show that they are biphasic. The core is a zinc blende monocrystal surrounded with single-crystal wurtzite. The GaN crystalline nanomesas have no threading dislocations or V-pits. This NSAG process potentially leads to integration of high-quality III-nitrides on the wafer scalable epitaxial graphene/silicon carbide platform.« less

Triangular arbitrage in the foreign exchange market

NASA Astrophysics Data System (ADS)

Aiba, Yukihiro; Hatano, Naomichi

2004-12-01

We first review our previous work, showing what is the triangular arbitrage transaction and how to quantify the triangular arbitrage opportunity. Next we explain that the correlation of the foreign exchange rates can appear without actual triangular arbitrage transaction.

The sail wing windmill and its adaptation for use in rural India

NASA Technical Reports Server (NTRS)

Sherman, M. M.

1973-01-01

An 8 meter-diameter prototype sail wing windmill is reported that uses a one meter-diameter bullock cartwheel to which three bamboo poles are latched in a triangular pattern with overlapping ends, to form the airframe for cloth sails. This device lifts 300 pounds to a height of 20 feet in one minute in a 10 mph wind.

Spin Bose-metal phase in a spin- (1)/(2) model with ring exchange on a two-leg triangular strip

NASA Astrophysics Data System (ADS)

Sheng, D. N.; Motrunich, Olexei I.; Fisher, Matthew P. A.

2009-05-01

Recent experiments on triangular lattice organic Mott insulators have found evidence for a two-dimensional (2D) spin liquid in close proximity to the metal-insulator transition. A Gutzwiller wave function study of the triangular lattice Heisenberg model with a four-spin ring exchange term appropriate in this regime has found that the projected spinon Fermi sea state has a low variational energy. This wave function, together with a slave particle-gauge theory analysis, suggests that this putative spin liquid possesses spin correlations that are singular along surfaces in momentum space, i.e., “Bose surfaces.” Signatures of this state, which we will refer to as a “spin Bose metal” (SBM), are expected to manifest in quasi-one-dimensional (quasi-1D) ladder systems: the discrete transverse momenta cut through the 2D Bose surface leading to a distinct pattern of 1D gapless modes. Here, we search for a quasi-1D descendant of the triangular lattice SBM state by exploring the Heisenberg plus ring model on a two-leg triangular strip (zigzag chain). Using density matrix renormalization group (DMRG) supplemented by variational wave functions and a bosonization analysis, we map out the full phase diagram. In the absence of ring exchange the model is equivalent to the J1-J2 Heisenberg chain, and we find the expected Bethe-chain and dimerized phases. Remarkably, moderate ring exchange reveals a new gapless phase over a large swath of the phase diagram. Spin and dimer correlations possess singular wave vectors at particular “Bose points” (remnants of the 2D Bose surface) and allow us to identify this phase as the hoped for quasi-1D descendant of the triangular lattice SBM state. We use bosonization to derive a low-energy effective theory for the zigzag spin Bose metal and find three gapless modes and one Luttinger parameter controlling all power law correlations. Potential instabilities out of the zigzag SBM give rise to other interesting phases such as a period-3 valence bond solid or a period-4 chirality order, which we discover in the DMRG. Another interesting instability is into a spin Bose-metal phase with partial ferromagnetism (spin polarization of one spinon band), which we also find numerically using the DMRG.

Penetration Characteristics of Air, Carbon Dioxide and Helium Transverse Sonic Jets in Mach 5 Cross Flow.

PubMed

Erdem, Erinc; Kontis, Konstantinos; Saravanan, Selvaraj

2014-12-08

An experimental investigation of sonic air, CO 2 and Helium transverse jets in Mach 5 cross flow was carried out over a flat plate. The jet to freestream momentum flux ratio, J, was kept the same for all gases. The unsteady flow topology was examined using high speed schlieren visualisation and PIV. Schlieren visualisation provided information regarding oscillating jet shear layer structures and bow shock, Mach disc and barrel shocks. Two-component PIV measurements at the centreline, provided information regarding jet penetration trajectories. Barrel shocks and Mach disc forming the jet boundary were visualised/quantified also jet penetration boundaries were determined. Even though J is kept the same for all gases, the penetration patterns were found to be remarkably different both at the nearfield and the farfield. Air and CO 2 jet resulted similar nearfield and farfield penetration pattern whereas Helium jet spread minimal in the nearfield.

Penetration Characteristics of Air, Carbon Dioxide and Helium Transverse Sonic Jets in Mach 5 Cross Flow

PubMed Central

Erdem, Erinc; Kontis, Konstantinos; Saravanan, Selvaraj

2014-01-01

An experimental investigation of sonic air, CO2 and Helium transverse jets in Mach 5 cross flow was carried out over a flat plate. The jet to freestream momentum flux ratio, J, was kept the same for all gases. The unsteady flow topology was examined using high speed schlieren visualisation and PIV. Schlieren visualisation provided information regarding oscillating jet shear layer structures and bow shock, Mach disc and barrel shocks. Two-component PIV measurements at the centreline, provided information regarding jet penetration trajectories. Barrel shocks and Mach disc forming the jet boundary were visualised/quantified also jet penetration boundaries were determined. Even though J is kept the same for all gases, the penetration patterns were found to be remarkably different both at the nearfield and the farfield. Air and CO2 jet resulted similar nearfield and farfield penetration pattern whereas Helium jet spread minimal in the nearfield. PMID:25494348

On some labelings of triangular snake and central graph of triangular snake graph

NASA Astrophysics Data System (ADS)

Agasthi, P.; Parvathi, N.

2018-04-01

A Triangular snake Tn is obtained from a path u 1 u 2 … u n by joining ui and u i+1 to a new vertex wi for 1≤i≤n‑1. A Central graph of Triangular snake C(T n ) is obtained by subdividing each edge of Tn exactly once and joining all the non adjacent vertices of Tn . In this paper the ways to construct square sum, square difference, Root Mean square, strongly Multiplicative, Even Mean and Odd Mean labeling for Triangular Snake and Central graph of Triangular Snake graphs are reported.

Miniaturized dual band multislotted patch antenna on polytetrafluoroethylene glass microfiber reinforced for C/X band applications.

PubMed

Islam, M T; Samsuzzaman, M

2014-01-01

This paper introduces a new configuration of compact, triangular- and diamond-slotted, microstrip-fed, low-profile antenna for C/X band applications on polytetrafluoroethylene glass microfiber reinforced material substrate. The antenna is composed of a rectangular-shaped patch containing eight triangles and two diamond-shaped slots and an elliptical-slotted ground plane. The rectangular-shaped patch is obtained by cutting two diamond slots in the middle of the rectangular patch, six triangular slots on the left and right side of the patch, and two triangular slots on the up and down side of the patch. The slotted radiating patch, the elliptical-slotted ground plane, and the microstrip feed enable the matching bandwidth to be widened. A prototype of the optimized antenna was fabricated on polytetrafluoroethylene glass microfiber reinforced material substrate using LPKF prototyping machine and investigated to validate the proposed design. The simulated results are compared with the measured data, and good agreement is achieved. The proposed antenna offers fractional bandwidths of 13.69% (7.78-8.91 GHz) and 10.35% (9.16-10.19 GHz) where S11 < -10 dB at center frequencies of 8.25 GHz and 9.95 GHz, respectively, and relatively stable gain, good radiation efficiency, and omnidirectional radiation patterns in the matching band.

Modelling the effects of penetrance and family size on rates of sporadic and familial disease.

PubMed

Al-Chalabi, Ammar; Lewis, Cathryn M

2011-01-01

Many complex diseases show a diversity of inheritance patterns ranging from familial disease, manifesting with autosomal dominant inheritance, through to simplex families in which only one person is affected, manifesting as apparently sporadic disease. The role of ascertainment bias in generating apparent patterns of inheritance is often overlooked. We therefore explored the role of two key parameters that influence ascertainment, penetrance and family size, in rates of observed familiality. We develop a mathematical model of familiality of disease, with parameters for penetrance, mutation frequency and family size, and test this in a complex disease: amyotrophic lateral sclerosis. Monogenic, high-penetrance variants can explain patterns of inheritance in complex diseases and account for a large proportion of those with no apparent family history. With current demographic trends, rates of familiality will drop further. For example, a variant with penetrance 0.5 will cause apparently sporadic disease in 12% of families of size 10, but 80% of families of size 1. A variant with penetrance 0.9 has only an 11% chance of appearing sporadic in families of a size similar to those of Ireland in the past, compared with 57% in one-child families like many in China. These findings have implications for genetic counselling, disease classification and the design of gene-hunting studies. The distinction between familial and apparently sporadic disease should be considered artificial. Copyright © 2011 S. Karger AG, Basel.

Geometric Triangular Chiral Hexagon Crystal-Like Complexes Organization in Pathological Tissues Biological Collision Order

PubMed Central

Díaz, Jairo A.; Jaramillo, Natalia A.; Murillo, Mauricio F.

2007-01-01

The present study describes and documents self-assembly of geometric triangular chiral hexagon crystal like complex organizations (GTCHC) in human pathological tissues.The authors have found this architectural geometric expression at macroscopic and microscopic levels mainly in cancer processes. This study is based essentially on macroscopic and histopathologic analyses of 3000 surgical specimens: 2600 inflammatory lesions and 400 malignant tumours. Geometric complexes identified photographically at macroscopic level were located in the gross surgical specimen, and these areas were carefully dissected. Samples were taken to carry out histologic analysis. Based on the hypothesis of a collision genesis mechanism and because it is difficult to carry out an appropriate methodological observation in biological systems, the authors designed a model base on other dynamic systems to obtain indirect information in which a strong white flash wave light discharge, generated by an electronic device, hits over the lines of electrical conductance structured in helicoidal pattern. In their experimental model, the authors were able to reproduce and to predict polarity, chirality, helicoid geometry, triangular and hexagonal clusters through electromagnetic sequential collisions. They determined that similar events among constituents of extracelular matrix which drive and produce piezoelectric activity are responsible for the genesis of GTCHC complexes in pathological tissues. This research suggests that molecular crystals represented by triangular chiral hexagons derived from a collision-attraction event against collagen type I fibrils emerge at microscopic and macroscopic scales presenting a lateral assembly of each side of hypertrophy helicoid fibers, that represent energy flow in cooperative hierarchically chiral electromagnetic interaction in pathological tissues and arises as a geometry of the equilibrium in perturbed biological systems. Further interdisciplinary studies must be carried out to reproduce, manipulate and amplify their activity and probably use them as a base to develop new therapeutic strategies in cancer. PMID:18074008

Penetration pattern of rhodamine dyes into enamel and dentin: confocal laser microscopy observation.

PubMed

Kwon, S R; Wertz, P W; Li, Y; Chan, D C N

2012-02-01

Enamel and dentin are susceptible to extrinsic and intrinsic stains. The purposes of this study were to determine the penetration pattern of Rhodamine B and dextran-conjugated Rhodamine B into the enamel and dentin as observed by confocal laser microscopy and to relate it to the penetration pattern of hydrogen peroxide commonly used as an active ingredient in tooth-whitening agents and high-molecular-weight staining molecules. Eighteen recently extracted human maxillary anterior teeth were used. Teeth were cleaned and painted with nail varnish except for the crown area above the cemento-enamel junction (CEJ). The painted teeth were then immersed in Rhodamine B and dextran-conjugated Rhodamine B (70 000 MW) for 4, 7, 10 and 15 days. Teeth were sliced to 3 mm thickness in transverse plane and mounted on a glass slide just prior to observation with confocal laser microscopy. Rhodamine B and dextran-conjugated Rhodamine B readily penetrated into the enamel and dentin when exposed for 4 and 7 days, respectively. Rhodamine B penetrated along the interprismatic spaces of the enamel into the dentin. The penetration was accentuated in sections with existing crack lines in the enamel. Rhodamine B was readily absorbed into the dentinal tubules at the dentino-enamel junction and continued to penetrate through the dentin via the dentinal tubules into the pre-dentin. Within the limitations of this study, it is concluded that Rhodamine B and dextran-conjugated Rhodamine B when applied to the external surface of the tooth readily penetrate into the enamel and dentin via the interprismatic spaces in the enamel and dentinal tubules in the dentin, suggesting that stain molecules and bleaching agents possibly exhibit similar penetration pathways. © 2011 The Authors. ICS © 2011 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

Tests of Si(111)-7 × 7 structural models by comparison with transmission electron diffraction patterns

NASA Astrophysics Data System (ADS)

McRae, E. G.; Petroff, P. M.

1984-11-01

Several structural models of the Si(111)-7 × 7 surface are tested by comparing calculated and observed transmission electron diffraction (TED) patterns. The models comprise "adatom" models where the unit mesh contains 12 adatoms or atom clusters in a locally (2 × 2) arrangement, and "triangle-dimer" models where the unit mesh contains 9 dimers or pairs of dimers bordering a triangular subunit of the unit mesh. The distribution of diffraction intensity among fractional-order spots is calculated kinematically and compared with TED patterns observed by Petroff and Wilson and others. No agreement is found for adatom models. Good but not perfect agreement is found for one triangle-dimer model.

Hierarchically triangular prism structured Co3O4: Self-supported fabrication and photocatalytic property

EPA Science Inventory

The formation of ammonium cobalt (II) phosphate was utilized to synthesize unprecedented 3D structures of Co3O4, triangular prisms and trunk-like structures, via a self-supported and organics-free method. The length of a triangular side of the prepared 3D triangular prisms is ~1...

Polyvinylpyrrolidone adsorption effects on the morphologies of synthesized platinum particles and its catalytic activity

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

Ooi, Mahayatun Dayana Johan; Aziz, Azlan Abdul; Nanobiotechnology Research and Innovation

Flower-like Platinum micro-structures were synthesized from different concentration of the PVP using solvothermal method. At 5.0×10{sup −3} mmol of PVP, well-defined flower-like pattern consists of triangular petals radiating from the centre were produced whereas larger flower network developed at higher PVP concentration. High degree of crystallinity was obtained upon each increment of PVP. The well defined flower like pattern synthesized using 5.0×10{sup −3} mmol PVP exhibit the highest catalytic activity and stability towards electro-oxidation of formic acid.

Role-separating ordering in social dilemmas controlled by topological frustration

NASA Astrophysics Data System (ADS)

Amaral, Marco A.; Perc, Matjaž; Wardil, Lucas; Szolnoki, Attila; da Silva Júnior, Elton J.; da Silva, Jafferson K. L.

2017-03-01

``Three is a crowd" is an old proverb that applies as much to social interactions as it does to frustrated configurations in statistical physics models. Accordingly, social relations within a triangle deserve special attention. With this motivation, we explore the impact of topological frustration on the evolutionary dynamics of the snowdrift game on a triangular lattice. This topology provides an irreconcilable frustration, which prevents anticoordination of competing strategies that would be needed for an optimal outcome of the game. By using different strategy updating protocols, we observe complex spatial patterns in dependence on payoff values that are reminiscent to a honeycomb-like organization, which helps to minimize the negative consequence of the topological frustration. We relate the emergence of these patterns to the microscopic dynamics of the evolutionary process, both by means of mean-field approximations and Monte Carlo simulations. For comparison, we also consider the same evolutionary dynamics on the square lattice, where of course the topological frustration is absent. However, with the deletion of diagonal links of the triangular lattice, we can gradually bridge the gap to the square lattice. Interestingly, in this case the level of cooperation in the system is a direct indicator of the level of topological frustration, thus providing a method to determine frustration levels in an arbitrary interaction network.

Role-separating ordering in social dilemmas controlled by topological frustration.

PubMed

Amaral, Marco A; Perc, Matjaž; Wardil, Lucas; Szolnoki, Attila; da Silva Júnior, Elton J; da Silva, Jafferson K L

2017-03-01

''Three is a crowd" is an old proverb that applies as much to social interactions as it does to frustrated configurations in statistical physics models. Accordingly, social relations within a triangle deserve special attention. With this motivation, we explore the impact of topological frustration on the evolutionary dynamics of the snowdrift game on a triangular lattice. This topology provides an irreconcilable frustration, which prevents anticoordination of competing strategies that would be needed for an optimal outcome of the game. By using different strategy updating protocols, we observe complex spatial patterns in dependence on payoff values that are reminiscent to a honeycomb-like organization, which helps to minimize the negative consequence of the topological frustration. We relate the emergence of these patterns to the microscopic dynamics of the evolutionary process, both by means of mean-field approximations and Monte Carlo simulations. For comparison, we also consider the same evolutionary dynamics on the square lattice, where of course the topological frustration is absent. However, with the deletion of diagonal links of the triangular lattice, we can gradually bridge the gap to the square lattice. Interestingly, in this case the level of cooperation in the system is a direct indicator of the level of topological frustration, thus providing a method to determine frustration levels in an arbitrary interaction network.

Bio-synthesis of triangular and hexagonal gold nanoparticles using palm oil fronds’ extracts at room temperature

NASA Astrophysics Data System (ADS)

Usman, Adamu Ibrahim; Aziz, Azlan Abdul; Abu Noqta, Osama

2018-01-01

Development of bio-reduction techniques for nanoparticles (NPs) synthesis in medical application remains a challenge to numerous researchers. This work reports a novel technique for the synthesis of triangular and hexagonal gold nanoparticles (AuNP) using palm oil fronds’ (POFs) extracts. The functional groups in the POFs’ extracts operate as a persuasive capping and reducing agent to growth AuNPs. The prepared AuNPs were characterized using UV-vis spectrophotometry, Fourier-transform infrared (FTIR) spectroscopy, dynamic light scattering, energy filtered transmission electron microscopy (EFTEM), and x-ray diffraction (XRD). The analysis of FTIR validates the coating of alkynes and phenolic composites on the AuNPs. This shows a feasible function of biomolecules for efficient stabilization of the AuNPs. EFTEM clearly show the triangular and hexagonal shapes of the prepared AuNPs. The XRD patterns display the peaks of fcc crystal structures at (111), (200), (220), (311) and (222), with average particle sizes of 66.7 and 79.02 nm for 1% and 5% POFs extracts concentrations respectively at room temperature. While at 120 °C the average particles size recorded for 1% and 5% of POFs extract concentrations were 32.17 nm and 45.66 nm respectively, and the reaction completed in less than 2 min. The prepared NPs could be potentially applied in biomedical application, due to their excellent stability and refine morphology without agglomeration.

Miniaturized Dual Band Multislotted Patch Antenna on Polytetrafluoroethylene Glass Microfiber Reinforced for C/X Band Applications

PubMed Central

Islam, M. T.; Samsuzzaman, M.

2014-01-01

This paper introduces a new configuration of compact, triangular- and diamond-slotted, microstrip-fed, low-profile antenna for C/X band applications on polytetrafluoroethylene glass microfiber reinforced material substrate. The antenna is composed of a rectangular-shaped patch containing eight triangles and two diamond-shaped slots and an elliptical-slotted ground plane. The rectangular-shaped patch is obtained by cutting two diamond slots in the middle of the rectangular patch, six triangular slots on the left and right side of the patch, and two triangular slots on the up and down side of the patch. The slotted radiating patch, the elliptical-slotted ground plane, and the microstrip feed enable the matching bandwidth to be widened. A prototype of the optimized antenna was fabricated on polytetrafluoroethylene glass microfiber reinforced material substrate using LPKF prototyping machine and investigated to validate the proposed design. The simulated results are compared with the measured data, and good agreement is achieved. The proposed antenna offers fractional bandwidths of 13.69% (7.78–8.91 GHz) and 10.35% (9.16–10.19 GHz) where S11 < −10 dB at center frequencies of 8.25 GHz and 9.95 GHz, respectively, and relatively stable gain, good radiation efficiency, and omnidirectional radiation patterns in the matching band. PMID:24987742

The correlation of initial radiographic characteristics of distal radius fractures and injuries of the triangular fibrocartilage complex.

PubMed

Kasapinova, K; Kamiloski, V

2016-06-01

Our purpose was to determine the correlation of initial radiographic parameters of a distal radius fracture with an injury of the triangular fibrocartilage complex. In a prospective study, 85 patients with surgically treated distal radius fractures were included. Wrist arthroscopy was used to identify and classify triangular fibrocartilage complex lesions. The initial radial length and angulation, dorsal angulation, ulnar variance and distal radioulnar distance were measured. Wrist arthroscopy identified a triangular fibrocartilage complex lesion in 45 patients. Statistical analysis did not identify a correlation with any single radiographic parameter of the distal radius fractures with the associated triangular fibrocartilage complex injuries. The initial radiograph of a distal radius fracture does not predict a triangular fibrocartilage complex injury. III. © The Author(s) 2016.

Hesitant triangular fuzzy information aggregation operators based on Bonferroni means and their application to multiple attribute decision making.

PubMed

Wang, Chunyong; Li, Qingguo; Zhou, Xiaoqiang; Yang, Tian

2014-01-01

We investigate the multiple attribute decision-making (MADM) problems with hesitant triangular fuzzy information. Firstly, definition and some operational laws of hesitant triangular fuzzy elements are introduced. Then, we develop some hesitant triangular fuzzy aggregation operators based on Bonferroni means and discuss their basic properties. Some existing operators can be viewed as their special cases. Next, we apply the proposed operators to deal with multiple attribute decision-making problems under hesitant triangular fuzzy environment. Finally, an illustrative example is given to show the developed method and demonstrate its practicality and effectiveness.

Hesitant Triangular Fuzzy Information Aggregation Operators Based on Bonferroni Means and Their Application to Multiple Attribute Decision Making

PubMed Central

Zhou, Xiaoqiang; Yang, Tian

2014-01-01

We investigate the multiple attribute decision-making (MADM) problems with hesitant triangular fuzzy information. Firstly, definition and some operational laws of hesitant triangular fuzzy elements are introduced. Then, we develop some hesitant triangular fuzzy aggregation operators based on Bonferroni means and discuss their basic properties. Some existing operators can be viewed as their special cases. Next, we apply the proposed operators to deal with multiple attribute decision-making problems under hesitant triangular fuzzy environment. Finally, an illustrative example is given to show the developed method and demonstrate its practicality and effectiveness. PMID:25140338

Series of Reciprocal Triangular Numbers

ERIC Educational Resources Information Center

Bruckman, Paul; Dence, Joseph B.; Dence, Thomas P.; Young, Justin

2013-01-01

Reciprocal triangular numbers have appeared in series since the very first infinite series were summed. Here we attack a number of subseries of the reciprocal triangular numbers by methodically expressing them as integrals.

A Generalization of the Formula for the Triangular Number of the Sum and Product of Natural Numbers

ERIC Educational Resources Information Center

Asiru, M. A.

2008-01-01

This note generalizes the formula for the triangular number of the sum and product of two natural numbers to similar results for the triangular number of the sum and product of "r" natural numbers. The formula is applied to derive formula for the sum of an odd and an even number of consecutive triangular numbers.

Breathing simulator of workers for respirator performance test.

PubMed

Yuasa, Hisashi; Kumita, Mikio; Honda, Takeshi; Kimura, Kazushi; Nozaki, Kosuke; Emi, Hitoshi; Otani, Yoshio

2015-01-01

Breathing machines are widely used to evaluate respirator performance but they are capable of generating only limited air flow patterns, such as, sine, triangular and square waves. In order to evaluate the respirator performance in practical use, it is desirable to test the respirator using the actual breathing patterns of wearers. However, it has been a difficult task for a breathing machine to generate such complicated flow patterns, since the human respiratory volume changes depending on the human activities and workload. In this study, we have developed an electromechanical breathing simulator and a respiration sampling device to record and reproduce worker's respiration. It is capable of generating various flow patterns by inputting breathing pattern signals recorded by a computer, as well as the fixed air flow patterns. The device is equipped with a self-control program to compensate the difference in inhalation and exhalation volume and the measurement errors on the breathing flow rate. The system was successfully applied to record the breathing patterns of workers engaging in welding and reproduced the breathing patterns.

Micrometeoroid and Orbital Debris Threat Assessment: Mars Sample Return Earth Entry Vehicle

NASA Technical Reports Server (NTRS)

Christiansen, Eric L.; Hyde, James L.; Bjorkman, Michael D.; Hoffman, Kevin D.; Lear, Dana M.; Prior, Thomas G.

2011-01-01

This report provides results of a Micrometeoroid and Orbital Debris (MMOD) risk assessment of the Mars Sample Return Earth Entry Vehicle (MSR EEV). The assessment was performed using standard risk assessment methodology illustrated in Figure 1-1. Central to the process is the Bumper risk assessment code (Figure 1-2), which calculates the critical penetration risk based on geometry, shielding configurations and flight parameters. The assessment process begins by building a finite element model (FEM) of the spacecraft, which defines the size and shape of the spacecraft as well as the locations of the various shielding configurations. This model is built using the NX I-deas software package from Siemens PLM Software. The FEM is constructed using triangular and quadrilateral elements that define the outer shell of the spacecraft. Bumper-II uses the model file to determine the geometry of the spacecraft for the analysis. The next step of the process is to identify the ballistic limit characteristics for the various shield types. These ballistic limits define the critical size particle that will penetrate a shield at a given impact angle and impact velocity. When the finite element model is built, each individual element is assigned a property identifier (PID) to act as an index for its shielding properties. Using the ballistic limit equations (BLEs) built into the Bumper-II code, the shield characteristics are defined for each and every PID in the model. The final stage of the analysis is to determine the probability of no penetration (PNP) on the spacecraft. This is done using the micrometeoroid and orbital debris environment definitions that are built into the Bumper-II code. These engineering models take into account orbit inclination, altitude, attitude and analysis date in order to predict an impacting particle flux on the spacecraft. Using the geometry and shielding characteristics previously defined for the spacecraft and combining that information with the environment model calculations, the Bumper-II code calculates a probability of no penetration for the spacecraft.

Seismic imaging of a fractured gas hydrate system in the Krishna-Godavari Basin offshore India

USGS Publications Warehouse

Riedel, M.; Collett, T.S.; Kumar, P.; Sathe, A.V.; Cook, A.

2010-01-01

Gas hydrate was discovered in the Krishna-Godavari (KG) Basin during the India National Gas Hydrate Program (NGHP) Expedition 1 at Site NGHP-01-10 within a fractured clay-dominated sedimentary system. Logging-while-drilling (LWD), coring, and wire-line logging confirmed gas hydrate dominantly in fractures at four borehole sites spanning a 500m transect. Three-dimensional (3D) seismic data were subsequently used to image the fractured system and explain the occurrence of gas hydrate associated with the fractures. A system of two fault-sets was identified, part of a typical passive margin tectonic setting. The LWD-derived fracture network at Hole NGHP-01-10A is to some extent seen in the seismic data and was mapped using seismic coherency attributes. The fractured system around Site NGHP-01-10 extends over a triangular-shaped area of ~2.5 km2 defined using seismic attributes of the seafloor reflection, as well as " seismic sweetness" at the base of the gas hydrate occurrence zone. The triangular shaped area is also showing a polygonal (nearly hexagonal) fault pattern, distinct from other more rectangular fault patterns observed in the study area. The occurrence of gas hydrate at Site NGHP-01-10 is the result of a specific combination of tectonic fault orientations and the abundance of free gas migration from a deeper gas source. The triangular-shaped area of enriched gas hydrate occurrence is bound by two faults acting as migration conduits. Additionally, the fault-associated sediment deformation provides a possible migration pathway for the free gas from the deeper gas source into the gas hydrate stability zone. It is proposed that there are additional locations in the KG Basin with possible gas hydrate accumulation of similar tectonic conditions, and one such location was identified from the 3D seismic data ~6 km NW of Site NGHP-01-10. ?? 2010.

Mathematical model of parking space unit for triangular parking area

NASA Astrophysics Data System (ADS)

Syahrini, Intan; Sundari, Teti; Iskandar, Taufiq; Halfiani, Vera; Munzir, Said; Ramli, Marwan

2018-01-01

Parking space unit (PSU) is an effective measure for the area size of a vehicle, including the free space and the width of the door opening of the vehicle (car). This article discusses a mathematical model for parking space of vehicles in triangular shape area. An optimization model for triangular parking lot is developed. Integer Linear Programming (ILP) method is used to determine the maximum number of the PSU. The triangular parking lot is in isosceles and equilateral triangles shape and implements four possible rows and five possible angles for each field. The vehicles which are considered are cars and motorcycles. The results show that the isosceles triangular parking area has 218 units of optimal PSU, which are 84 units of PSU for cars and 134 units of PSU for motorcycles. Equilateral triangular parking area has 688 units of optimal PSU, which are 175 units of PSU for cars and 513 units of PSU for motorcycles.

Magnetic order in a frustrated two-dimensional atom lattice at a semiconductor surface.

PubMed

Li, Gang; Höpfner, Philipp; Schäfer, Jörg; Blumenstein, Christian; Meyer, Sebastian; Bostwick, Aaron; Rotenberg, Eli; Claessen, Ralph; Hanke, Werner

2013-01-01

Two-dimensional electron systems, as exploited for device applications, can lose their conducting properties because of local Coulomb repulsion, leading to a Mott-insulating state. In triangular geometries, any concomitant antiferromagnetic spin ordering can be prevented by geometric frustration, spurring speculations about 'melted' phases, known as spin liquid. Here we show that for a realization of a triangular electron system by epitaxial atom adsorption on a semiconductor, such spin disorder, however, does not appear. Our study compares the electron excitation spectra obtained from theoretical simulations of the correlated electron lattice with data from high-resolution photoemission. We find that an unusual row-wise antiferromagnetic spin alignment occurs that is reflected in the photoemission spectra as characteristic 'shadow bands' induced by the spin pattern. The magnetic order in a frustrated lattice of otherwise non-magnetic components emerges from longer-range electron hopping between the atoms. This finding can offer new ways of controlling magnetism on surfaces.

Fall Down Detection Under Smart Home System.

PubMed

Juang, Li-Hong; Wu, Ming-Ni

2015-10-01

Medical technology makes an inevitable trend for the elderly population, therefore the intelligent home care is an important direction for science and technology development, in particular, elderly in-home safety management issues become more and more important. In this research, a low of operation algorithm and using the triangular pattern rule are proposed, then can quickly detect fall-down movements of humanoid by the installation of a robot with camera vision at home that will be able to judge the fall-down movements of in-home elderly people in real time. In this paper, it will present a preliminary design and experimental results of fall-down movements from body posture that utilizes image pre-processing and three triangular-mass-central points to extract the characteristics. The result shows that the proposed method would adopt some characteristic value and the accuracy can reach up to 90 % for a single character posture. Furthermore the accuracy can be up to 100 % when a continuous-time sampling criterion and support vector machine (SVM) classifier are used.

Molecular Mechanism Responsible for Reentrance to Ia3d Gyroid Phase in Cubic Mesogen BABH(n)

NASA Astrophysics Data System (ADS)

Nakazawa, Yuri; Yamamura, Yasuhisa; Kutsumizu, Shoichi; Saito, Kazuya

2012-09-01

Maximum entropy analyses of small-angle X-ray diffraction patterns of a series of title compounds [1,2-bis(4'-n-alkyloxybenzoyl)hydrazine, n: number of carbon atoms in an alkyl group] yield a new description of the so-called gyroid phase. The structure is described as two sets of connected triangles, instead of jungle gyms consisting of rods, embedded in two spaces separated by a mathematical gyroid. The reconstructed electron density provides new evidence of molecular packing: While molecules having short alkyl chains laterally aggregate to form single layers of triangular shape with nearly vertical alignments, those with long chains split into two groups on both sides of the triangular planes. The formation of double layers of the molecular cores is tolerable with the possible formation of hydrogen bonds between shifted molecules, and adjusts the volume fraction of the core part to attain the stability of the reentrant gyroid phase upon chain elongation.

Photonic confinement in laterally structured metal-organic microcavities

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

Mischok, Andreas, E-mail: andreas.mischok@iapp.de; Brückner, Robert; Sudzius, Markas

2014-08-04

We investigate the formation of optical modes in organic microcavities with an incorporated perforated silver layer. The metal leads to a formation of Tamm-plasmon-polaritons and thus separates the sample into metal-free or metal-containing areas, supporting different resonances. This mode splitting is exploited to confine photons in elliptic holes and triangular cuts, forming distinctive standing wave patterns showing the strong lateral confinement. A comparison with a Maxwell-Bloch based rate equation model clearly shows the nonlinear transition into the lasing regime. The concentration of the electric field density and inhibition of lateral loss channels in turn decreases the lasing threshold by upmore » to one order of magnitude, to 0.1 nJ. By spectroscopic investigation of such a triangular wedge, we observe the transition from the unperturbed cavity state to a strongly confined complex transversal mode. Such a structured silver layer can be utilized in future for charge carrier injection in an electrically driven organic solid state laser.« less

California coast nearshore processes study

NASA Technical Reports Server (NTRS)

Pirie, D. M. (Principal Investigator)

1972-01-01

The author has identified the following significant results. In the Santa Barbara Channel the effect of the California and the Anacapa Currents are clearly seen in image 1109-18073M. The large triangular shaped lobe of suspended particulate matter that stretches almost to Anacapa Island from the Ventura River area is disrupted approximately midchannel by the east-moving Anacapa Current. In the Point Conception area a lobe of suspended material approximately 20 miles long can be seen moving eastward as a result of the California Current. In the San Francisco Bay area the major results include the detection and delineation of the San Francisco Bay, the location and vector of suspended sediment in the San Francisco Bay, and the ability to differentiate morphologic units within the San Francisco Bay tidelands. Several densitometer line traces seaward of the Golden Gate Bridge on image 1075-18173-4 outline the San Francisco Bay and give evidence of good water penetration.

The triangular kagomé lattices revisited

NASA Astrophysics Data System (ADS)

Liu, Xiaoyun; Yan, Weigen

2013-11-01

The dimer problem, Ising spins and bond percolation on the triangular kagomé lattice have been studied extensively by physicists. In this paper, based on the fact the triangular kagomé lattice with toroidal boundary condition can be regarded as the line graph of 3.12.12 lattice with toroidal boundary condition, we derive the formulae of the number of spanning trees, the energy, and the Kirchhoff index of the triangular kagomé lattice with toroidal boundary condition.

Classification of ulnar triangular fibrocartilage complex tears. A treatment algorithm for Palmer type IB tears.

PubMed

Atzei, A; Luchetti, R; Garagnani, L

2017-05-01

The classical definition of 'Palmer Type IB' triangular fibrocartilage complex tear, includes a spectrum of clinical conditions. This review highlights the clinical and arthroscopic criteria that enable us to categorize five classes on a treatment-oriented classification system of triangular fibrocartilage complex peripheral tears. Class 1 lesions represent isolated tears of the distal triangular fibrocartilage complex without distal radio-ulnar joint instability and are amenable to arthroscopic suture. Class 2 tears include rupture of both the distal triangular fibrocartilage complex and proximal attachments of the triangular fibrocartilage complex to the fovea. Class 3 tears constitute isolated ruptures of the proximal attachment of the triangular fibrocartilage complex to the fovea; they are not visible at radio-carpal arthroscopy. Both Class 2 and Class 3 tears are diagnosed with a positive hook test and are typically associated with distal radio-ulnar joint instability. If required, treatment is through reattachment of the distal radio-ulnar ligament insertions to the fovea. Class 4 lesions are irreparable tears due to the size of the defect or to poor tissue quality and, if required, treatment is through distal radio-ulnar ligament reconstruction with tendon graft. Class 5 tears are associated with distal radio-ulnar joint arthritis and can only be treated with salvage procedures. This subdivision of type IB triangular fibrocartilage complex tear provides more insights in the pathomechanics and treatment strategies. II.

Characterization of Martian Rock Shape for MER Airbag Drop Tests

NASA Astrophysics Data System (ADS)

Dimaggio, E. N.; Schroeder, R.; Castle, N.; Golombek, M.

2002-12-01

Rock distributions for the final platforms used in airbag drop tests are currently being designed for the Mars Exploration Rovers (MER) scheduled to launch in 2003. Like Mars Pathfinder (MPF), launched in 1996, MER will use a series of airbags to cushion its landing on the surface of Mars. Previous MER airbag drop tests have shown that sharp, angular (triangular) rocks >20 cm high may be hazardous. To aid in defining the rock distributions for the final airbag tests, images from the Viking Landers 1 and 2 and MPF were used to identify rocks that are >20 cm high, and characterize them as triangular, square or round. Approximately 33% of all rocks analyzed are triangular. Of the rocks analyzed that are ~20-60 cm high, ~14% are triangular. Most of these triangular rocks are small, ~20-30 cm high. Rock distributions of previous airbag platforms were similarly classified and show a greater percentage of triangular and square rocks that are ~20-60 cm high than at the landing sites. The burial of a rock (perched, partially buried or buried) was also considered because perched rocks may pose less of a threat to the airbags than those buried because perched rocks can be dislodged and roll during impact. Approximately 19% of all rocks analyzed, and ~19% of rocks that are ~20-60 cm high, are triangular and partially buried or buried. These data suggest that the platform rock distributions appropriately represented the risks to the airbags associated with triangular rocks. A similar percentage of >20 cm high triangular rocks will be added to the drop test platforms to represent landing site rock distributions.

Analytical review of 664 cases of penetrating buttock trauma

PubMed Central

2011-01-01

A comprehensive review of data has not yet been provided as penetrating injury to the buttock is not a common condition accounting for 2-3% of all penetrating injuries. The aim of the study is to provide the as yet lacking analytical review of the literature on penetrating trauma to the buttock, with appraisal of characteristics, features, outcomes, and patterns of major injuries. Based on these results we will provide an algorithm. Using a set of terms we searched the databases Pub Med, EMBASE, Cochran, and CINAHL for articles published in English between 1970 and 2010. We analysed cumulative data from prospective and retrospective studies, and case reports. The literature search revealed 36 relevant articles containing data on 664 patients. There was no grade A evidence found. The injury population mostly consists of young males (95.4%) with a high proportion missile injury (75.9%). Bleeding was found to be the key problem which mostly occurs from internal injury and results in shock in 10%. Overall mortality is 2.9% with significant adverse impact of visceral or vascular injury and shock (P < 0.001). The major injury pattern significantly varies between shot and stab injury with small bowel, colon, or rectum injuries leading in shot wounds, whilst vascular injury leads in stab wounds (P < 0.01). Laparotomy was required in 26.9% of patients. Wound infection, sepsis or multiorgan failure, small bowel fistula, ileus, rebleeding, focal neurologic deficit, and urinary tract infection were the most common complications. Sharp differences in injury pattern endorse an algorithm for differential therapy of penetrating buttock trauma. In conclusion, penetrating buttock trauma should be regarded as a life-threatening injury with impact beyond the pelvis until proven otherwise. PMID:21995834

Submicron patterns obtained by thermal-induced reconstruction of self-assembled monolayer of Ag nanoparticles and their application in SERS

NASA Astrophysics Data System (ADS)

Ruan, Weidong; Zhou, Tieli; Cui, Yinqiu; Dong, Yujie; Liu, Zhuo; Dong, Fengxia; Wang, Haiyang; Luan, Xintong; Wang, Xu; Song, Wei; Zhao, Bing

2014-08-01

The layer-by-layer (LbL) self-assembly technique was employed for the deposition of poly(diallyldimethylammonium chloride) (PDDA) and triangular Ag nanoplates on glass substrates. A thermal-induced reconstruction of these polyelectrolyte-linked nanoparticle (NP) films was presented. Before the reconstruction, triangular Ag nanoplates were distributed uniformly on the surface with an average interval of 50 ± 15 nm. After the reconstruction, the triangular Ag nanoplates accumulated into discrete stacks with an average interval of 90 ± 25 nm. The temperature-dependent experiments were done and the optimal temperature for the formation of the reconstructed patterns was 120 °C. The possible mechanism of the NP movement and stacking was analyzed. Under the experimental conditions, a hydrophobic environment was formed because of the vacuum and heating. As a result the polyelectrolyte-linked Ag NPs preferred to congregate due to the lowered surface energy. Finally the submicron patterns were formed. The ultraviolet-visible (UV-vis) absorption and surface-enhanced Raman scattering (SERS) properties of the films before and after the reconstruction was investigated. The reconstructed films with submicron patterns had better SERS enhancement ability, which was 1300 times to the original films. The reconstruction method of the monolayer films showed great potential in the surface design and related applications. AFM images were obtained to clarify the three dimensional structures of the reconstructed films obtained at 120 °C. As shown in Fig. 2, the Ag NP stacks had an average diameter of 1.0 ± 0.2 μm and an average height of 170 ± 30 nm. The diameter and height of the stacks were shaped by the aggregates of tens of triangular Ag nanoplates. The AFM cross-sectional contour showed the clear intervals of the stacks, which was corresponding to the SEM characterization.XRD patterns of the polyelectrolyte-linked NP films before and after thermal post-treatment are showed in Fig. 3. The peak at 38.1° was corresponding to the diffraction of the {1 1 1} plane of Ag NPs. No other diffraction peaks was observable because the Ag NPs grew at the {1 1 1} plane preferred in our synthesis method. The intensity of the peaks changed slightly, which is attributed to the change of the orientation of NPs.The possible mechanism for the reconstruction was discussed. In our experiments, the as-prepared polyelectrolyte-linked NP films were located in a very hydrophobic environment in the post-treatment process. To minimize interfacial free energy, both the polar groups of PDDA and the Ag NPs preferred to accumulate to lower the surface area, viz. surface tension [22,23]. As a result, the uniform films converted to the discrete islands on glass substrates. The mechanism is illustrated in Fig. 4.It should note that the NPs did not undergo an obvious phase change in our experimental conditions. From the SEM in Fig. 1(b) it can be seen that the shape of triangular silver nanoplates did not change perceptibly. Moreover, the XRD patterns in Fig. 3 also did not show big changes in the peak intensities. The slight intensity change of the diffraction peaks at 38.1° is assigned to the change of the orientation of NPs, which happens usually in any reconstruction of NP films.The reconstruction of the NP films provides an opportunity to produce surface modifications which have applications in optical properties. The SPR and enhanced spectroscopy properties were investigated by UV-vis absorption and SERS, respectively. Fig. 5(a) shows the UV-vis absorption spectra of the Ag colloid, Ag NP films before and after the post-treatment at 120 °C. In the visible region the triangular Ag nanoplates have two adsorption bands centered at 675 and 490 nm. These absorption bands are assigned to be the in-plane dipole and the in-plane quadruple plasmon resonances, separately [24]. After the deposition of the triangular Ag NPs on glass slides, the UV-vis absorption bands appeared to be 627 and 454 nm, which are similar to the reported results [24]. When the Ag NP films underwent the thermal post-treatment at 120 °C, an absorption band at 410 nm was generated, which is generally assigned to be the strong coupling SPR of Ag NP aggregates. The relative stronger absorption near 514.5 nm comparing with the Ag NP films before the reconstruction could contribute more enhancement with the excitation line of 514.5 nm when the films were used as SERS substrates.Fig. 5(b) shows the SERS spectra of 4-ATP adsorbed on the Ag NP films before and after the reconstruction. The SERS measurements were prepared by drop coating of 10 μL of 4-ATP (10-5 mol/L) ethanol solution onto the reconstructed films and 10 μL of 4-ATP (10-3 mol/L) ethanol solution onto the original films, separately. Then they were dried naturally. 10 (±0.5) mm diameter circular blots were formed on the substrates. The peak at 1077 cm-1 was chosen for quantitative comparison of the enhancement ability of these films. Because the enhancement is proportional to the concentration of the 4-ATP molecule and the intensity of the SERS signal in our experiments, it is easy to obtain the quantitative comparison for the NP films. As results, the enhancement of the reconstructed films is 1300 times to the original films. The reconstruction of the NP films created more “hot spots” by the aggregation of Ag NPs, which has great contribution to the enhancement according to the electromagnetic mechanism of SERS. Other delicate works also showed the importance for the engineering fabrication of nanogaps with plasmonic materials [25-27]. Our method shows potential application to the fabrication of high-active SERS substrates via a convenient and inexpensive way.

Magnetoresistance measurement of permalloy thin film rings with triangular fins

NASA Astrophysics Data System (ADS)

Lai, Mei-Feng; Hsu, Chia-Jung; Liao, Chun-Neng; Chen, Ying-Jiun; Wei, Zung-Hang

2010-01-01

Magnetization reversals in permalloy rings controlled by nucleation sites using triangular fins at the same side and diagonal with respect to the field direction are demonstrated by magnetoresistance measurement and micromagnetic simulation. In the ring with triangular fins at the same side, there exists two-step reversal from onion to flux-closure state (or vortex state) and then from flux-closure (or vortex state) to reverse onion state; in the ring with diagonal triangular fins, one-step reversal occurs directly from onion to reverse onion state. The reversal processes are repeatable and controllable in contrast to an ideal ring without triangular fins where one-step and two-step reversals occur randomly in sweep-up and sweep-down processes.

Benchmarks of simple, generic, shaped plates for validation of low-frequency electromagnetic computational codes

NASA Technical Reports Server (NTRS)

Deshpande, M. D.; Cockrell, C. R.; Beck, F. B.; Nguyen, T. X.

1993-01-01

The validation of low-frequency measurements and electromagnetic (EM) scattering computations for several simple, generic shapes, such as an equilateral-triangular plate, an equilateral-triangular plate with a concentric equilateral-triangular hole, and diamond- and hexagonal-shaped plates, is discussed. The plates were constructed from a thin aluminum sheet with a thickness of 0.08 cm. EM scattering by the planar plates was measured in the experimental test range (ETR) facility of NASA Langley Research Center. The dimensions of the plates were selected such that, over the frequency range of interest, the dimensions were in the range of lambda0 to 3(lambda0). In addition, the triangular plate with a triangular hole was selected to study internal-hole resonances.

A comparative evaluation of the in vitro penetration performance of the improved Crest complete toothbrush versus the Current Crest complete toothbrush, the Colgate Precision toothbrush and the Oral-B P40 toothbrush.

PubMed

Volpenhein, D W; Handel, S E; Hughes, T J; Wild, J

1996-01-01

Removal of plaque and debris from interproximal surfaces during toothbrushing has generally been difficult to achieve, in large part because traditional flat-bristled toothbrushes do not offer good interproximal penetration. As a result, a number of varying bristle designs have been developed, with the rippled-design brush shown to be particularly effective at removing interproximal plaque. Recently, an existing brush, the original Crest Complete, was modified to offer a more deeply rippled version. This study evaluated the interproximal penetration of four bristle designs: rippled pattern (original Crest Complete), deeper rippled pattern (improved Crest Complete), multi-level (Colgate Precision), and flat-tufted (Oral-B P40). The study used a previously reported in vitro model for determining interproximal penetration of manual toothbrushes (J Clin Dent 5:27-33, 1994). In order to effectively mimic the in-use characteristics of toothbrushing, this model is based on analysis of videotaped consumer brushing habits, tooth morphology, and in vivo plaque tenacity characteristics and uses the three most predominantly used brushing techniques (circular, up-and-down, and back-and-forth, with the brush held at both 45 and 90 degrees to the tooth surface). In addition, the model's brush stroke length, brush force, and brush speed are likewise based on analysis of consumer brushing patterns. The results of the study indicate that the new Crest Complete with deeper rippled bristles provided significantly superior (p < or = 0.05) interproximal penetration than the Colgate Precision and Oral-B brushes overall and for three of the four brush strokes tested. In addition, the new Crest Complete was found to provide significantly superior interproximal penetration to the original Crest Complete overall and in circular and up-and-down strokes, and the original Crest Complete provided superior overall interproximal penetration to the Colgate and Oral-B brushes.

Cultural Resources Inventory of Lands Adjacent to Big Sandy Lake. Volume 1,

DTIC Science & Technology

1979-01-18

population density. Late Prehistoric: 300 - 1640 A.D. Intensive wild rice -bison economic systems; St. Croix, Kathio, Clam River, Balckduck and Sandy...type are located on W- streams and near lake outlets that tend to be good wild rice harvesting .1. areas. Projectile points are either ososceles...triangular br side-notched points. The subsistence pattern of these people is that of hunting deer and smaller mammals and wild rice gathering. The time

7 CFR 810.1002 - Definition of other terms.

Code of Federal Regulations, 2014 CFR

2014-01-01

... seeds. All matter that passes through a 5/64 triangular-hole sieve after sieving according to procedures..., rye, safflower, sorghum, soybeans, spelt, sunflower seed, sweet corn, triticale, and wheat. (e) Sieves—(1) 5/64 triangular-hole sieve. A metal sieve 0.032 inch thick with equilateral triangular...

7 CFR 810.1002 - Definition of other terms.

Code of Federal Regulations, 2012 CFR

2012-01-01

... seeds. All matter that passes through a 5/64 triangular-hole sieve after sieving according to procedures..., rye, safflower, sorghum, soybeans, spelt, sunflower seed, sweet corn, triticale, and wheat. (e) Sieves—(1) 5/64 triangular-hole sieve. A metal sieve 0.032 inch thick with equilateral triangular...

7 CFR 810.1002 - Definition of other terms.

Code of Federal Regulations, 2013 CFR

2013-01-01

... seeds. All matter that passes through a 5/64 triangular-hole sieve after sieving according to procedures..., rye, safflower, sorghum, soybeans, spelt, sunflower seed, sweet corn, triticale, and wheat. (e) Sieves—(1) 5/64 triangular-hole sieve. A metal sieve 0.032 inch thick with equilateral triangular...

Triangular Diagrams Teach Steady and Dynamic Behaviour of Catalytic Reactions.

ERIC Educational Resources Information Center

Klusacek, K.; And Others

1989-01-01

Illustrates how triangular diagrams can aid in presenting some of the rather complex transient interactions that occur among gas and surface species during heterogeneous catalytic reactions. The basic equations and numerical examples are described. Classroom use of the triangular diagram is discussed. Several diagrams and graphs are provided. (YP)

On Certain Topological Indices of Boron Triangular Nanotubes

NASA Astrophysics Data System (ADS)

Aslam, Adnan; Ahmad, Safyan; Gao, Wei

2017-08-01

The topological index gives information about the whole structure of a chemical graph, especially degree-based topological indices that are very useful. Boron triangular nanotubes are now replacing usual carbon nanotubes due to their excellent properties. We have computed general Randić (Rα), first Zagreb (M1) and second Zagreb (M2), atom-bond connectivity (ABC), and geometric-arithmetic (GA) indices of boron triangular nanotubes. Also, we have computed the fourth version of atom-bond connectivity (ABC4) and the fifth version of geometric-arithmetic (GA5) indices of boron triangular nanotubes.

Adaptive non-predictor control of lower triangular uncertain nonlinear systems with an unknown time-varying delay in the input

NASA Astrophysics Data System (ADS)

Koo, Min-Sung; Choi, Ho-Lim

2018-01-01

In this paper, we consider a control problem for a class of uncertain nonlinear systems in which there exists an unknown time-varying delay in the input and lower triangular nonlinearities. Usually, in the existing results, input delays have been coupled with feedforward (or upper triangular) nonlinearities; in other words, the combination of lower triangular nonlinearities and input delay has been rare. Motivated by the existing controller for input-delayed chain of integrators with nonlinearity, we show that the control of input-delayed nonlinear systems with two particular types of lower triangular nonlinearities can be done. As a control solution, we propose a newly designed feedback controller whose main features are its dynamic gain and non-predictor approach. Three examples are given for illustration.

Breathing simulator of workers for respirator performance test

PubMed Central

YUASA, Hisashi; KUMITA, Mikio; HONDA, Takeshi; KIMURA, Kazushi; NOZAKI, Kosuke; EMI, Hitoshi; OTANI, Yoshio

2014-01-01

Breathing machines are widely used to evaluate respirator performance but they are capable of generating only limited air flow patterns, such as, sine, triangular and square waves. In order to evaluate the respirator performance in practical use, it is desirable to test the respirator using the actual breathing patterns of wearers. However, it has been a difficult task for a breathing machine to generate such complicated flow patterns, since the human respiratory volume changes depending on the human activities and workload. In this study, we have developed an electromechanical breathing simulator and a respiration sampling device to record and reproduce worker’s respiration. It is capable of generating various flow patterns by inputting breathing pattern signals recorded by a computer, as well as the fixed air flow patterns. The device is equipped with a self-control program to compensate the difference in inhalation and exhalation volume and the measurement errors on the breathing flow rate. The system was successfully applied to record the breathing patterns of workers engaging in welding and reproduced the breathing patterns. PMID:25382381

Intra-abdominal primary monophasic synovial sarcoma with hemangiopericytoma-like areas.

PubMed

Rao, Lakshmi; Jaiprakash, Padmapriya; Palankar, Nagaraj; Gowda, Vinay

2013-01-01

We report a case of retroperitoneal intra-abdominal primary monophasic synovial sarcoma (SS) with hemangiopericytomatous (HPC) pattern in a 25-year-old male arising from the triangular ligament on the superior surface of liver encasing the inferior vena cava (IVC) and masquerading as a hepatic tumor. A large heterogeneously enhancing, well defined, lobulated, exophytic lesion was seen involving segment VIII of the liver with foci of calcification in the periphery. A biopsy, followed by total resection of the tumor, showed a spindle cell sarcoma with HPC pattern, which was consistent with monophasic SS on histology and immunohistochemistry. The unusual clinical presentation, radiology, pathology, and differential diagnosis will be discussed in detail.

Host Penetration and Emergence Patterns of the Mosquito-Parasitic Mermithids Romanomermis iyengari and Strelkovimermis spiculatus (Nematoda: Mermithidae)

PubMed Central

Sanad, Manar M.; Shamseldean, Muhammad S. M.; Elgindi, Abd-Elmoneim Y.; Gaugler, Randy

2013-01-01

Romanomermis iyengari and Strelkovimermis spiculatus are mermithid nematodes that parasitize mosquito larvae. We describe host penetration and emergence patterns of Romanomermis iyengari and Strelkovimermis spiculatus in laboratory exposures against Culex pipiens pipiens larvae. The mermithid species differed in host penetration behavior, with R. iyengari juveniles attaching to the host integument before assuming a rigid penetration posture at the lateral thorax (66.7%) or abdominal segments V to VIII (33.3%). Strelkovimermis spiculatus attached first to a host hair in a coiled posture that provided a stable base for penetration, usually through the lateral thorax (83.3%). Superparasitism was reduced by discriminating against previously infected hosts, but R. iyengari’s ability to avoid superparasitism declined at a higher inoculum rate. Host emergence was signaled by robust nematode movements that induced aberrant host swimming. Postparasites of R. iyengari usually emerged from the lateral prothorax (93.2%), whereas S. spiculatus emergence was peri-anal. In superparasitized hosts, emergence was initiated by males in R. iyengari and females in S. spiculatus; emergence was otherwise nearly synchronous. Protandry was observed in R. iyengari. The ability of S. spiculatus to sustain an optimal sex ratio suggested superior self-regulation. Mermithid penetration and emergence behaviors and sites may be supplementary clues for identification. Species differences could be useful in developing production and release strategies. PMID:23589657

7 CFR 810.802 - Definition of other terms.

Code of Federal Regulations, 2012 CFR

2012-01-01

... and fines. All matter other than whole flaxseed that passes through a 5/64 triangular-hole sieve, and... established under the Act, that are materially discolored and damaged by heat. (e) Sieve— 5/64 triangular-hole sieve. A metal sieve 0.032 inch thick with equilateral triangular perforations the inscribed circles of...

7 CFR 810.802 - Definition of other terms.

Code of Federal Regulations, 2013 CFR

2013-01-01

... and fines. All matter other than whole flaxseed that passes through a 5/64 triangular-hole sieve, and... established under the Act, that are materially discolored and damaged by heat. (e) Sieve— 5/64 triangular-hole sieve. A metal sieve 0.032 inch thick with equilateral triangular perforations the inscribed circles of...

7 CFR 810.802 - Definition of other terms.

Code of Federal Regulations, 2011 CFR

2011-01-01

... and fines. All matter other than whole flaxseed that passes through a 5/64 triangular-hole sieve, and... established under the Act, that are materially discolored and damaged by heat. (e) Sieve— 5/64 triangular-hole sieve. A metal sieve 0.032 inch thick with equilateral triangular perforations the inscribed circles of...

7 CFR 810.802 - Definition of other terms.

Code of Federal Regulations, 2014 CFR

2014-01-01

... and fines. All matter other than whole flaxseed that passes through a 5/64 triangular-hole sieve, and... established under the Act, that are materially discolored and damaged by heat. (e) Sieve— 5/64 triangular-hole sieve. A metal sieve 0.032 inch thick with equilateral triangular perforations the inscribed circles of...

Sorption of Triangular Silver Nanoplates on Polyurethane Foam

NASA Astrophysics Data System (ADS)

Furletov, A. A.; Apyari, V. V.; Garshev, A. V.; Volkov, P. A.; Tolmacheva, V. V.; Dmitrienko, S. G.

2018-02-01

The sorption of triangular silver nanoplates on polyurethane foam is investigated as a procedure for creating a nanocomposite sensing material for subsequent use in optical means of chemical analysis. Triangular silver nanoplates are synthesized and characterized, and a simple sorption technique for the formation of a composite material based on these nanoplates is proposed.

Properties of plane discrete Poisson-Voronoi tessellations on triangular tiling formed by the Kolmogorov-Johnson-Mehl-Avrami growth of triangular islands

NASA Astrophysics Data System (ADS)

Korobov, A.

2011-08-01

Discrete uniform Poisson-Voronoi tessellations of two-dimensional triangular tilings resulting from the Kolmogorov-Johnson-Mehl-Avrami (KJMA) growth of triangular islands have been studied. This shape of tiles and islands, rarely considered in the field of random tessellations, is prompted by the birth-growth process of Ir(210) faceting. The growth mode determines a triangular metric different from the Euclidean metric. Kinetic characteristics of tessellations appear to be metric sensitive, in contrast to area distributions. The latter have been studied for the variant of nuclei growth to the first impingement in addition to the conventional case of complete growth. Kiang conjecture works in both cases. The averaged number of neighbors is six for all studied densities of random tessellations, but neighbors appear to be mainly different in triangular and Euclidean metrics. Also, the applicability of the obtained results for simulating birth-growth processes when the 2D nucleation and impingements are combined with the 3D growth in the particular case of similar shape and the same orientation of growing nuclei is briefly discussed.

Properties of plane discrete Poisson-Voronoi tessellations on triangular tiling formed by the Kolmogorov-Johnson-Mehl-Avrami growth of triangular islands.

PubMed

Korobov, A

2011-08-01

Discrete uniform Poisson-Voronoi tessellations of two-dimensional triangular tilings resulting from the Kolmogorov-Johnson-Mehl-Avrami (KJMA) growth of triangular islands have been studied. This shape of tiles and islands, rarely considered in the field of random tessellations, is prompted by the birth-growth process of Ir(210) faceting. The growth mode determines a triangular metric different from the Euclidean metric. Kinetic characteristics of tessellations appear to be metric sensitive, in contrast to area distributions. The latter have been studied for the variant of nuclei growth to the first impingement in addition to the conventional case of complete growth. Kiang conjecture works in both cases. The averaged number of neighbors is six for all studied densities of random tessellations, but neighbors appear to be mainly different in triangular and Euclidean metrics. Also, the applicability of the obtained results for simulating birth-growth processes when the 2D nucleation and impingements are combined with the 3D growth in the particular case of similar shape and the same orientation of growing nuclei is briefly discussed.

Tuning quadratic nonlinear photonic crystal fibers for zero group-velocity mismatch.

PubMed

Bache, Morten; Nielsen, Hanne; Laegsgaard, Jesper; Bang, Ole

2006-06-01

We consider an index-guiding silica photonic crystal fiber with a triangular hole pattern and a periodically poled quadratic nonlinearity. By tuning the pitch and the relative hole size, second-harmonic generation with zero group-velocity mismatch is found for any fundamental wavelength above 780 nm. The nonlinear strength is optimized when the fundamental has maximum confinement in the core. The conversion bandwidth allows for femtosecond-pulse conversion, and 4%-180%W(-1)cm(-2) relative efficiencies were found.

Epitaxially Grown Colloidal Crystals of Silica Microspheres on Patterned Substrate of Triangular Arrays

DTIC Science & Technology

2008-07-16

min after addition of binary mixture. Other images are taken (d) after supernatant removal, (e) after ammonia exposure, ( f ) after air-drying and dye...12] J.P. Hoogenboom , D. Derks, P. Vergeer, A. van Blaaderen, J. Chem. Phys. 117 (2002) 11320. [13] A. van Blaaderen, R. Ruel, P. Wiltzius, Nature...Axe, Y. Fujii, Phys. Rev. Lett. 62 (1989) 1524. [19] F . El Azhar, M. Baus, J.P. Ryekaert, E.J. Meijer, J. Chem. Phys. 112 (2000) 5121. [20] M.S

A Ranking Analysis/An Interlinking Approach of New Triangular Fuzzy Cognitive Maps and Combined Effective Time Dependent Matrix

NASA Astrophysics Data System (ADS)

Adiga, Shreemathi; Saraswathi, A.; Praveen Prakash, A.

2018-04-01

This paper aims an interlinking approach of new Triangular Fuzzy Cognitive Maps (TrFCM) and Combined Effective Time Dependent (CETD) matrix to find the ranking of the problems of Transgenders. Section one begins with an introduction that briefly describes the scope of Triangular Fuzzy Cognitive Maps (TrFCM) and CETD Matrix. Section two provides the process of causes of problems faced by Transgenders using Fuzzy Triangular Fuzzy Cognitive Maps (TrFCM) method and performs the calculations using the collected data among the Transgender. In Section 3, the reasons for the main causes for the problems of the Transgenders. Section 4 describes the Charles Spearmans coefficients of rank correlation method by interlinking of Triangular Fuzzy Cognitive Maps (TrFCM) Method and CETD Matrix. Section 5 shows the results based on our study.

The frequency and spectrum of thymus 2-[fluorine-18] fluoro-2-deoxy-D-glucose uptake patterns in hyperthyroidism patients.

PubMed

Chen, Yen-Kung; Yeh, Chia-Lu; Chen, Yen-Ling; Wang, Su-Chen; Cheng, Ru-Hwa; Kao, Pan-Fu

2011-10-01

Thymic hyperplasia is associated with hyperthyroidism. Increased thymus 2-[fluorine-18]fluoro-2-deoxy-D-glucose (FDG) uptake in hyperthyroidism patients has been reported. The aim of this study was to analyze the FDG positron emission tomography (PET) thymus uptake spectrum in patients with active hyperthyroidism with correlation with serum hormones. The prospective study included FDG PET scans from 65 hyperthyroidism patients and 30 subjects with euthyroid status as control group. The intensity of FDG uptake in thyroid and thymus regions was graded subjectively on a five-point scale and semi-quantitatively by measuring standard uptake value (SUV). Correlation coefficient between thymus SUV and serum thyroxine, triiodothyronine, thyrotropin, thyroid peroxidase antibodies (TPO Ab), thyrotropin receptor autoantibody (TR Ab), and thymulin were analyzed. Among 65 hyperthyroidism patients, 30 (46.2%) and 39 (60%) patients showed thyroid and thymus FDG uptake, respectively. The frequency of thymus uptake FDG was high in patients younger than age 40 (28/31, 90.3%). The patterns of the thymic FDG uptake include inverted V or triangular, separated triangular, united nontriangular, unilateral right or left extension, and focal midline. Focal midline FDG uptake was the most common pattern (15/39, 38.5%). None of the control group showed thymus FDG uptake. The correlation coefficient between the FDG uptake SUV levels in thymus and serum hormones, thyrotropin, TPO Ab, TR Ab, and thymulin levels were all low (P > .05). In FDG PET scan, thymus activity was common in hyperthyroidism patients; this should not be misdiagnosed as a malignancy in patients exhibiting weight loss. Copyright © 2011 AUR. Published by Elsevier Inc. All rights reserved.

Penetration experiments in aluminum 1100 targets using soda-lime glass projectiles

NASA Technical Reports Server (NTRS)

Horz, Friedrich; Cintala, Mark J.; Bernhard, Ronald P.; Cardenas, Frank; Davidson, William E.; Haynes, Gerald; See, Thomas H.; Winkler, Jerry L.

1995-01-01

The cratering and penetration behavior of annealed aluminum 1100 targets, with thickness varied from several centimeters to ultra-thin foils less than 1 micrometer thick, were experimentally investigated using 3.2 mm diameter spherical soda-lime glass projectiles at velocities from 1 to 7 km/s. The objective was to establish quantitative, dimensional relationships between initial impact conditions (impact velocity, projectile diameter, and target thickness) and the diameter of the resulting crater or penetration hole. Such dimensional relationships and calibration experiments are needed to extract the diameters and fluxes of hypervelocity particles from space-exposed surfaces and to predict the performance of certain collisional shields. The cratering behavior of aluminum 1100 is fairly well predicted. However, crater depth is modestly deeper for our silicate impactors than the canonical value based on aluminum projectiles and aluminum 6061-T6 targets. The ballistic-limit thickness was also different. These differences attest to the great sensitivity of detailed crater geometry and penetration behavior on the physical properties of both the target and impactor. Each penetration experiment was equipped with a witness plate to monitor the nature of the debris plume emanating from the rear of the target. This plume consists of both projectile fragments and target debris. Both penetration hole and witness-plate spray patterns systematically evolve in response to projectile diameter/target thickness. The relative dimensions of the projectile and target totally dominate the experimental products documented in this report; impact velocity is an important contributor as well to the evolution of penetration holes, but is of subordinate significance for the witness-plate spray patterns.

From Cylindrical to Stretching Ridges and Wrinkles in Twisted Ribbons

NASA Astrophysics Data System (ADS)

Pham Dinh, Huy; Démery, Vincent; Davidovitch, Benny; Brau, Fabian; Damman, Pascal

2016-09-01

Twisted ribbons under tension exhibit a remarkably rich morphology, from smooth and wrinkled helicoids, to cylindrical or faceted patterns. This complexity emanates from the instability of the natural, helicoidal symmetry of the system, which generates both longitudinal and transverse stresses, thereby leading to buckling of the ribbon. Here, we focus on the tessellation patterns made of triangular facets. Our experimental observations are described within an "asymptotic isometry" approach that brings together geometry and elasticity. The geometry consists of parametrized families of surfaces, isometric to the undeformed ribbon in the singular limit of vanishing thickness and tensile load. The energy, whose minimization selects the favored structure among those families, is governed by the tensile work and bending cost of the pattern. This framework describes the coexistence lines in a morphological phase diagram, and determines the domain of existence of faceted structures.

Triangular Arbitrage as an Interaction in Foreign Exchange Markets

NASA Astrophysics Data System (ADS)

Aiba, Yukihiro; Hatano, Naomichi

Analyzing correlation in financial time series is a topic of considerable interest [1]-[17]. In the foreign exchange market, a correlation among the exchange rates can be generated by a triangular arbitrage transaction. The purpose of this article is to review our recent study [18]-[23] on modeling the interaction generated by the triangular arbitrage.

High-resolution 3-T MRI of the triangular fibrocartilage complex in the wrist: injury pattern and MR features.

PubMed

Zhan, Huili; Zhang, Huibo; Bai, Rongjie; Qian, Zhanhua; Liu, Yue; Zhang, Heng; Yin, Yuming

2017-12-01

To investigate if using high-resolution 3-T MRI can identify additional injuries of the triangular fibrocartilage complex (TFCC) beyond the Palmer classification. Eighty-six patients with surgically proven TFCC injury were included in this study. All patients underwent high-resolution 3-T MRI of the injured wrist. The MR imaging features of TFCC were analyzed according to the Palmer classification. According to the Palmer classification, 69 patients could be classified as having Palmer injuries (52 had traumatic tears and 17 had degenerative tears). There were 17 patients whose injuries could not be classified according to the Palmer classification: 13 had volar or dorsal capsular TFC detachment and 4 had a horizontal tear of the articular disk. Using high-resolution 3-T MRI, we have not only found all the TFCC injuries described in the Palmer classification, additional injury types were found in this study, including horizontal tear of the TFC and capsular TFC detachment. We propose the modified Palmer classification and add the injury types that were not included in the original Palmer classification.

Variation in shape of the lingula in the adult human mandible

PubMed Central

TULI, A.; CHOUDHRY, R.; CHOUDHRY, S.; RAHEJA, S.; AGARWAL, S.

2000-01-01

The lingulae of both sides of 165 dry adult human mandibles, 131 males and 34 females of Indian origin, were classified by their shape into 4 types: 1, triangular; 2, truncated; 3, nodular; and 4, assimilated. Triangular lingulae were found in 226 (68.5%) sides, truncated in 52 (15.8%), nodular in 36 (10.9%) and assimilated in 16 (4.8%) sides. Triangular lingulae were found bilaterally in 110, truncated in 23, nodular in 17 and assimilated in 7 mandibles. Of the remaining 8 mandibles with different appearances on the 2 sides, 6 had a combination of triangular and truncated and 2 had nodular and assimilated. The incidence of triangular and assimilated types in the male and female mandibles are almost equal. In the truncated type it was double in the male mandibles while the nodular type was a little less than double in the female mandibles. PMID:11005723

Facile synthesis of microporous SiO2/triangular Ag composite nanostructures for photocatalysis

NASA Astrophysics Data System (ADS)

Sirohi, Sidhharth; Singh, Anandpreet; Dagar, Chakit; Saini, Gajender; Pani, Balaram; Nain, Ratyakshi

2017-11-01

In this article, we present a novel fabrication of microporous SiO2/triangular Ag nanoparticles for dye (methylene blue) adsorption and plasmon-mediated degradation. Microporous SiO2 nanoparticles with pore size <2 nm were synthesized using cetyltrimethylammonium bromide as a structure-directing agent and functionalized with APTMS ((3-aminopropyl) trimethoxysilane) to introduce amine groups. Amine-functionalized microporous silica was used for adsorption of triangular silver (Ag) nanoparticles. The synthesized microporous SiO2 nanostructures were investigated for adsorption of different dyes including methylene blue, congo red, direct green 26 and curcumin crystalline. Amine-functionalized microporous SiO2/triangular Ag nanostructures were used for plasmon-mediated photocatalysis of methylene blue. The experimental results revealed that the large surface area of microporous silica facilitated adsorption of dye. Triangular Ag nanoparticles, due to their better charge carrier generation and enhanced surface plasmon resonance, further enhanced the photocatalysis performance.

Study on Dynamic Development of Three-dimensional Weld Pool Surface in Stationary GTAW

NASA Astrophysics Data System (ADS)

Huang, Jiankang; He, Jing; He, Xiaoying; Shi, Yu; Fan, Ding

2018-04-01

The weld pool contains abundant information about the welding process. In particular, the type of the weld pool surface shape, i. e., convex or concave, is determined by the weld penetration. To detect it, an innovative laser-vision-based sensing method is employed to observe the weld pool surface of the gas tungsten arc welding (GTAW). A low-power laser dots pattern is projected onto the entire weld pool surface. Its reflection is intercepted by a screen and captured by a camera. Then the dynamic development process of the weld pool surface can be detected. By observing and analyzing, the change of the reflected laser dots reflection pattern, for shape of the weld pool surface shape, was found to closely correlate to the penetration of weld pool in the welding process. A mathematical model was proposed to correlate the incident ray, reflected ray, screen and surface of weld pool based on structured laser specular reflection. The dynamic variation of the weld pool surface and its corresponding dots laser pattern were simulated and analyzed. By combining the experimental data and the mathematical analysis, the results show that the pattern of the reflected laser dots pattern is closely correlated to the development of weld pool, such as the weld penetration. The concavity of the pool surface was found to increase rapidly after the surface shape was changed from convex to concave during the stationary GTAW process.

Indications, techniques, and outcomes of arthroscopic repair of scapholunate ligament and triangular fibrocartilage complex.

PubMed

Mathoulin, C L

2017-07-01

This review includes updated understanding of the roles of intrinsic and extrinsic carpal ligaments in scapholunate instability and details the author's experience of indications, arthroscopic repair methods, and outcomes of treating the instability. A classification on triangular fibrocartilage complex injuries is reviewed, followed by author's indications, methods, and outcomes of arthroscopic repair of triangular fibrocartilage complex injuries.

26 CFR 1.367(b)-14T - Acquisition of parent stock for property in triangular reorganizations (temporary).

Code of Federal Regulations, 2010 CFR

2010-04-01

... 26 Internal Revenue 4 2010-04-01 2010-04-01 false Acquisition of parent stock for property in triangular reorganizations (temporary). 1.367(b)-14T Section 1.367(b)-14T Internal Revenue INTERNAL REVENUE... § 1.367(b)-14T Acquisition of parent stock for property in triangular reorganizations (temporary). (a...

Comparative analysis of film cooling efficiency at coolant supply into a single array of triangular dimples

NASA Astrophysics Data System (ADS)

Khalatov, A. A.; Petliak, O. O.; Severin, S. D.; Panchenko, N. A.

2018-03-01

The purpose of this work is a comparative study of the physical structure and film cooling efficiency of the single array of inclined holes, placed in triangular dimples and in a trench. The software package ANSYS CFX 17.0 was used along with RANS SST turbulence model. Calculations were made in a wide range of the blowing ratio ranging from 0.5 to 2.0. Results of modeling have shown high efficiency of triangular film cooling configuration. At m ≥ 1.5, the triangular configuration is comparable with the trench configuration in terms of the film cooling efficiency.

Nonzero θ13 from the Triangular Ansatz and Leptogenesis

NASA Astrophysics Data System (ADS)

Benaoum, H. B.

2012-08-01

Recent experiments indicate a departure from the exact tri-bimaximal mixing by measure ring definitive nonzero value of θ13. Within the framework of type I seesaw mechanism, we reconstruct the triangular Dirac neutrino mass matrix from the μ - τ symmetric mass matrix. The deviation from μ - τ symmetry is then parametrized by adding dimensionless parameters yi in the triangular mass matrix. In this parametrization of the neutrino mass matrix, the nonzero value θ13 is controlled by Δy = y4 - y6. We also calculate the resulting leptogenesis and show that the triangular texture can generate the observed baryon asymmetry in the universe via leptogenesis scenario.

Influence of two different flap designs on the sequelae of mandibular third molar surgery.

PubMed

Erdogan, Ozgür; Tatlı, Ufuk; Ustün, Yakup; Damlar, Ibrahim

2011-09-01

The aim of this study was to compare the influence of triangular and envelope flaps on trismus, pain, and facial swelling after mandibular third molar surgery. Twenty healthy patients with bilateral, symmetrically impacted mandibular third molars were included in this double-blinded, prospective, cross-over, randomized study. The patients were operated with envelope flap on one side and triangular flap on the other side. Trismus was determined by measuring maximum interincisal opening, and facial swelling was evaluated using a tape measuring method. Pain was determined using visual analog scale (VAS) and recording the number of pain pills taken. The facial swelling measurements and VAS scores were lower in the envelope flap group compared to the triangular flap group. There was no significant difference between the two flap designs in operation time, maximum interincisal opening, and the number of analgesics taken. Envelope flap yields to less facial swelling and reduced VAS scores in comparison to triangular flap. There is no clinical difference in trismus between the two flap designs. Despite the higher VAS scores with triangular flap, no additional doses of analgesics were required in triangular flap.

Balance of the stored energies sustained by the internal and edge transport barriers and effects of ELMs and L-H transitions in JT-60U

NASA Astrophysics Data System (ADS)

Kamada, Y.; Yoshida, M.; Sakamoto, Y.; Koide, Y.; Oyama, N.; Urano, H.; Kamiya, K.; Suzuki, T.; Isayama, A.; JT-60 Team

2009-09-01

To understand key physics processes determining radial profiles of the kinetic plasma parameters in the advanced tokamak operation scenarios, correlations between the edge transport barrier (ETB) and the internal transport barrier (ITB) have been studied in the JT-60U tokamak device. It has been found that the edge pedestal poloidal beta, βp-ped, increases almost linearly with the total poloidal beta, βp-tot, over a wide range of the plasma current for type I ELMing H-mode plasmas, and this dependence becomes stronger with increasing triangularity. This dependence is not due to the profile stiffness, since the dependence is the same regardless of the existence of ITB. As the stored energy inside the ITB-foot radius (WITB) increases, the total thermal stored energy (Wth) increases and then the pedestal stored energy (Wped) increases. On the other hand, as Wped increases, the ELM penetration expands more inwards and finally reaches the ITB-foot radius. At this situation, the ITB-foot radius cannot move outwards because of the erosion by ELMs. Then the fractions of WITB/Wth and Wped/Wth become almost constant. It has also been found that the type I ELM expels/decreases the edge toroidal momentum larger than the edge ion thermal energy. The ELM penetration for the toroidal rotation tends to be deeper than that for the ion temperature and can exceed the ITB-foot radius. The ELM penetration is deeper for CO-rotating plasmas than CTR rotating plasmas. In both cases, the ELM penetration is deeper in the order of the toroidal rotation (Vt), the ion temperature (Ti) and then the electron temperature (Te). The L-H transition also changes the Vt profile more significantly than the Ti profile. At the L-H transition, the pedestal Vt shifts into the CTR-direction deeply and suddenly without a change in Ti, and then the pedestal Vt grows further together with a growth of the pedestal Ti in a slower timescale. Such changes in Vt by ELMs and L-H transitions may affect degradation/evolution of ITBs.

Macroscopically detected female genital injury after consensual and non-consensual vaginal penetration: a prospective comparison study.

PubMed

Lincoln, Catherine; Perera, Rafael; Jacobs, Ian; Ward, Alison

2013-10-01

The aim of this study was to compare the prevalence, type and pattern of macroscopically detected female genital injury after consensual and non-consensual vaginal penetration to further an understanding of the forensic significance of genital injury in women reporting sexual assault. A secondary aim was to identify any effect of a range of possible variables upon the likelihood of genital injury resulting from vaginal penetrative sexual intercourse. Two groups of reproductive age women (aged 18-45 years) were prospectively recruited within 72 h of a single episode of vaginal penetrative sex, and macroscopically examined for the presence of bruises, abrasions and lacerations at twelve external and internal genital sites. Forty one women who presented for forensic examination after reporting a sexual assault to police were recruited to the non-consensual group and 81 women who presented for routine cervical screening or with sexual health concerns to a primary health care service to the consensual group. Each group was examined by a different group of doctors, all of whom were experienced in both forensic genital examination and gynaecological examination of healthy and diseased sexually active women. Data collection and examination protocols were the same for both groups. The key finding was a statistically significant difference in genital injury prevalence between women who were vaginally penetrated non-consensually and consensually; 53.7% of the non-consensual group (22/41) and 9.9% of the consensual group (8/81) were found to have at least one genital injury [OR 10.57, CI (4.07, 27.42), p < 0.00001]. Penetration with finger/s and possible pre-existing genital 'infection' were found to be significantly associated with the presence of injury in the univariate analysis after adjusting for consent. Logistic regression demonstrated that women penetrated without consent were 19.5 times more likely to sustain at least one genital injury, than those penetrated consensually [OR 19.53, CI (6.03, 63.24)] and that a penetration scenario that included finger/s was 4.2 times more likely to result in at least one genital injury than penetration without finger involvement [OR 4.25, CI (1.42, 12.78)], when controlling for other variables in the model. Whilst a comparatively low injury prevalence in the consensual group limited interpretation, results revealed possible differences in genital injury typology and pattern resulting from non-consensual and consensual vaginal penetration. Lacerations were seen after both consensual and non-consensual vaginal penetration, while abrasions and bruises were seen exclusively in the non-consensual group. This study demonstrated a significant consent group difference in genital injury prevalence and the highest macroscopically detected genital injury prevalence rate resulting from non-consensual vaginal penetration identified to date. Results also indicate that vaginal penetration with finger/s increases the likelihood of sex-related injury. The difference in type of injury sustained as a result of non-consensual and consensual vaginal penetration was an unexpected finding, and warrants further investigation. These results highlight the importance of a standardised means of detecting genital injury based on consistent injury definitions, examination protocols, and examiner experience and suggest that macroscopic genital examination may be uniquely placed to detect consent group differences in injury typology and pattern if they exist. Copyright © 2013 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

Laser Printing of Superhydrophobic Patterns from Mixtures of Hydrophobic Silica Nanoparticles and Toner Powder.

PubMed

Ngo, Chi-Vinh; Chun, Doo-Man

2016-11-08

In this work, a new and facile dry printing method was developed for the direct fabrication of superhydrophobic patterns based on silica nanoparticles. Mixtures of hydrophobic fumed silica nanoparticles and toner powder were printed on paper and polymer sheets using a commercial laser printer to produce the superhydrophobic patterns. The mixing ratio of the toner powder (for the laser printer) to hydrophobic silica was also investigated to optimize both the printing quality and the superhydrophobicity of the printed areas. The proper mixing ratio was then used to print various superhydrophobic patterns, including triangular, square, circular, and complex arrangements, to demonstrate that superhydrophobic surfaces with different patterns can be fabricated in a few seconds without any post-processing. The superhydrophobicity of each sample was evaluated by contact angle measurements, and all printed areas showed contact angles greater than 150°. The research described here opens the possibility of rapid production of superhydrophobic surfaces with various patterns. Ultimately, the obtained findings may have a significant impact on applications related to self-cleaning, control of water geometry and position, fluid mixing and fluid transport.

Laser Printing of Superhydrophobic Patterns from Mixtures of Hydrophobic Silica Nanoparticles and Toner Powder

PubMed Central

Ngo, Chi-Vinh; Chun, Doo-Man

2016-01-01

In this work, a new and facile dry printing method was developed for the direct fabrication of superhydrophobic patterns based on silica nanoparticles. Mixtures of hydrophobic fumed silica nanoparticles and toner powder were printed on paper and polymer sheets using a commercial laser printer to produce the superhydrophobic patterns. The mixing ratio of the toner powder (for the laser printer) to hydrophobic silica was also investigated to optimize both the printing quality and the superhydrophobicity of the printed areas. The proper mixing ratio was then used to print various superhydrophobic patterns, including triangular, square, circular, and complex arrangements, to demonstrate that superhydrophobic surfaces with different patterns can be fabricated in a few seconds without any post-processing. The superhydrophobicity of each sample was evaluated by contact angle measurements, and all printed areas showed contact angles greater than 150°. The research described here opens the possibility of rapid production of superhydrophobic surfaces with various patterns. Ultimately, the obtained findings may have a significant impact on applications related to self-cleaning, control of water geometry and position, fluid mixing and fluid transport. PMID:27824132

A comparative evaluation of the in vitro penetration performance of the improved Crest Complete toothbrush versus the Colgate Total toothbrush and the Oral-B Advantage toothbrush.

PubMed

Volpenhein, D W; Hartman, W L

1996-01-01

Removal of plaque and debris from interproximal surfaces during toothbrushing has generally been difficult to achieve, in large part because traditional flat-bristled toothbrushes do not offer good interproximal penetration. As a result, a number of varying bristle designs have been developed, with the rippled-design brush shown to be particularly effective at removing interproximal plaque. Recently, an existing rippled brush, the original Crest Complete, was modified to offer longer rippled outer tufts to clean along the gumline more effectively. Therefore, this study evaluated the overall and gumline interproximal penetration of three bristle designs: rippled, raised pattern (Improved Crest Complete); and two multi-level patterns (Colgate Total and Oral-B Advantage). The study used a previously reported in vitro model for determining interproximal penetration of manual toothbrushes (J Clin Dent 5:27-33, 1994). In order to effectively mimic the in-use characteristics of toothbrushing, this model is based on analysis of videotaped consumer brushing habits, tooth morphology, and in vivo plaque tenacity characteristics, and uses the three most predominantly used brushing techniques (circular, up-and-down, and back-and-forth with the brush held at both 45 degrees and 90 degrees to the tooth surface). In addition, the model's brush stroke length, brush force, and brush speed are likewise based on an analysis of consumer brushing patterns. The results of this study indicate that the Improved Crest Complete with longer rippled outer bristles provided significantly superior (p < 0.05) interproximal penetration overall and at the gumline than the Colgate Total and Oral-B Advantage brushes.

Incidence, Patterns, and Factors Predicting Mortality of Abdominal Injuries in Trauma Patients

PubMed Central

Gad, Mohammad A; Saber, Aly; Farrag, Shereif; Shams, Mohamed E; Ellabban, Goda M

2012-01-01

Background: Abdominal trauma is a major public health problem for all nations and all socioeconomic strata. Aim: This study was designed to determine the incidence and patterns of abdominal injuries in trauma patients. Materials and Methods: We classified and identified the incidence and subtype of abdominal injuries and associated trauma, and identified variables related to morbidity and mortality. Results: Abdominal trauma was present in 248 of 300 cases; 172 patients with blunt abdominal trauma and 76 with penetrating. The most frequent type of abdominal trauma was blunt trauma; its most common cause was motor vehicle accident. Among patients with penetrating abdominal trauma, the most common cause was stabbing. Most abdominal trauma patients presented with other injuries, especially patients with blunt abdominal trauma. Mortality was higher among penetrating abdominal trauma patients. Conclusions: Type of abdominal trauma, associated injuries, and Revised Trauma Score are independent risk factors for mortality in abdominal trauma patients. PMID:22454826

PPF Dependent Fixed Point Results for Triangular α c-Admissible Mappings

PubMed Central

Ćirić, Ljubomir; Alsulami, Saud M.; Salimi, Peyman

2014-01-01

We introduce the concept of triangular α c-admissible mappings (pair of mappings) with respect to η c nonself-mappings and establish the existence of PPF dependent fixed (coincidence) point theorems for contraction mappings involving triangular α c-admissible mappings (pair of mappings) with respect to η c nonself-mappings in Razumikhin class. Several interesting consequences of our theorems are also given. PMID:24672352

50 CFR Figures 18a, 18b and 18c to... - Large Frame TED Escape Opening; Minimum Dimensions Using All-Bar Cuts (Triangular Cuts); Large...

Code of Federal Regulations, 2013 CFR

2013-10-01

... Dimensions Using All-Bar Cuts (Triangular Cuts); Large Frame TED Escape Opening; Minimum Dimensions Using All-Bar Cuts and Leading Edge Cut; Large Frame TED Escape Opening; Minimum Dimensions Using All-Points...—Large Frame TED Escape Opening; Minimum Dimensions Using All-Bar Cuts (Triangular Cuts); Large Frame TED...

50 CFR Figures 18a, 18b and 18c to... - Large Frame TED Escape Opening; Minimum Dimensions Using All-Bar Cuts (Triangular Cuts); Large...

Code of Federal Regulations, 2012 CFR

2012-10-01

... Dimensions Using All-Bar Cuts (Triangular Cuts); Large Frame TED Escape Opening; Minimum Dimensions Using All-Bar Cuts and Leading Edge Cut; Large Frame TED Escape Opening; Minimum Dimensions Using All-Points...—Large Frame TED Escape Opening; Minimum Dimensions Using All-Bar Cuts (Triangular Cuts); Large Frame TED...

50 CFR Figures 18a, 18b and 18c to... - Large Frame TED Escape Opening; Minimum Dimensions Using All-Bar Cuts (Triangular Cuts); Large...

Code of Federal Regulations, 2014 CFR

2014-10-01

... Dimensions Using All-Bar Cuts (Triangular Cuts); Large Frame TED Escape Opening; Minimum Dimensions Using All-Bar Cuts and Leading Edge Cut; Large Frame TED Escape Opening; Minimum Dimensions Using All-Points...—Large Frame TED Escape Opening; Minimum Dimensions Using All-Bar Cuts (Triangular Cuts); Large Frame TED...

Diagnosing central lesions of the triangular fibrocartilage as traumatic or degenerative: a review of clinical accuracy.

PubMed

Löw, S; Erne, H; Pillukat, T; Mühldorfer-Fodor, M; Unglaub, F; Spies, C K

2017-05-01

This study examined the reliability of surgeons' estimations as to whether central lesions of the triangular fibrocartilage complex were traumatic or degenerative. A total of 50 consecutive central triangular fibrocartilage complex lesions were independently rated by ten experienced wrist surgeons viewing high-quality arthroscopy videos. The videos were reassessed after intervals of 3 months; at the second assessment surgeons were given the patient's history, radiographs and both, each in a randomized order. Finally, the surgeons assessed the histories and radiographs without the videos. Kappa statistics revealed fair interrater agreement when the histories were added to the videos. The other four modalities demonstrated moderate agreement, with lower Kappa values for the assessment without videos. Intra-rater reliability showed fair agreement for three surgeons, moderate agreement for two surgeons and substantial agreement for five surgeons. It appears that classification of central triangular fibrocartilage complex lesions depends on the information provided upon viewing the triangular fibrocartilage complex at arthroscopy. II.

Patients with triangular fibrocartilage complex injuries and distal radioulnar joint instability have reduced rotational torque in the forearm.

PubMed

Andersson, J K; Axelsson, P; Strömberg, J; Karlsson, J; Fridén, J

2016-09-01

A total of 20 patients scheduled for wrist arthroscopy, all with clinical signs of rupture to the triangular fibrocartilage complex and distal radioulnar joint instability, were tested pre-operatively by an independent observer for strength of forearm rotation. During surgery, the intra-articular pathology was documented by photography and also subsequently individually analysed by another independent hand surgeon. Arthroscopy revealed a type 1-B injury to the triangular fibrocartilage complex in 18 of 20 patients. Inter-rater reliability between the operating surgeon and the independent reviewer showed absolute agreement in all but one patient (95%) in terms of the injury to the triangular fibrocartilage complex and its classification. The average pre-operative torque strength was 71% of the strength of the non-injured contralateral side in pronation and supination. Distal radioulnar joint instability with an arthroscopically verified injury to the triangular fibrocartilage complex is associated with a significant loss of both pronation and supination torque. Case series, Level IV. © The Author(s) 2015.

Anisotropic magnetic properties of the triangular plane lattice material TmMgGaO 4

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

Cevallos, F. Alex; Stolze, Karoline; Kong, Tai

Here, the crystal growth, structure, and basic magnetic properties of TmMgGaO 4 are reported. The Tm ions are located in a planar triangular lattice consisting of distorted TmO6 octahedra, while the Mg and Ga atoms randomly occupy intermediary bilayers of M-O triangular bipyramids. The Tm ions are positionally disordered. The material displays an antiferromagnetic Curie Weiss theta of ~ -20 -25 K, with no clear ordering visible in the magnetic susceptibility down to 1.8 K; the structure and magnetic properties suggest that ordering of the magnetic moments is frustrated by both structural disorder and the triangular magnetic motif. Single crystalmore » magnetization measurements indicate that the magnetic properties are highly anisotropic, with large moments measured perpendicular to the triangular planes. At 2 K, a broad step-like feature is seen in the field-dependent magnetization perpendicular to the plane on applied field near 2 Tesla.« less

[Fluorescence Resonance Energy Transfer Detection of Cobalt Ions by Silver Triangular Nanoplates and Rhodamine 6G].

PubMed

Zhang, Xiu-qing; Peng, Jun; Ling, Jian; Liu, Chao-juan; Cao, Qiu-e; Ding, Zhong-tao

2015-04-01

In the present paper, the authors studied fluorescence resonance energy transfer (FRET) phenomenon between silver triangular nanoplates and bovine serum albumin (BSA)/Rhodamine 6G fluorescence complex, and established a fluorescence method for the detection of cobalt ions. We found that when increasing the silver triangular nanoplates added to certain concentrations of fluorescent bovine serum albumin (BSA)/Rhodamine 6G complex, the fluorescence of Rhodamine 6G would be quenched up to 80% due to the FRET between the quencher and donor. However, in the presence of cobalt ions, the disassociation of the fluorescent complex from silver triangular nanoplates occurred and the fluorescence of the Rhodamine 6G recovered. The recovery of fluorescence intensity rate (I/I0) has a good relationship with the cobalt ion concentration (cCO2+) added. Thus, the authors developed a fluorescence method for the detection of cobalt ions based on the FRET of silver triangular nanoplates and Rhodamine 6G.

Simultaneous travel time tomography for updating both velocity and reflector geometry in triangular/tetrahedral cell model

NASA Astrophysics Data System (ADS)

Bai, Chao-ying; He, Lei-yu; Li, Xing-wang; Sun, Jia-yu

2018-05-01

To conduct forward and simultaneous inversion in a complex geological model, including an irregular topography (or irregular reflector or velocity anomaly), we in this paper combined our previous multiphase arrival tracking method (referred as triangular shortest-path method, TSPM) in triangular (2D) or tetrahedral (3D) cell model and a linearized inversion solver (referred to as damped minimum norms and constrained least squares problem solved using the conjugate gradient method, DMNCLS-CG) to formulate a simultaneous travel time inversion method for updating both velocity and reflector geometry by using multiphase arrival times. In the triangular/tetrahedral cells, we deduced the partial derivative of velocity variation with respective to the depth change of reflector. The numerical simulation results show that the computational accuracy can be tuned to a high precision in forward modeling and the irregular velocity anomaly and reflector geometry can be accurately captured in the simultaneous inversion, because the triangular/tetrahedral cell can be easily used to stitch the irregular topography or subsurface interface.

Simultaneous travel time tomography for updating both velocity and reflector geometry in triangular/tetrahedral cell model

NASA Astrophysics Data System (ADS)

Bai, Chao-ying; He, Lei-yu; Li, Xing-wang; Sun, Jia-yu

2017-12-01

To conduct forward and simultaneous inversion in a complex geological model, including an irregular topography (or irregular reflector or velocity anomaly), we in this paper combined our previous multiphase arrival tracking method (referred as triangular shortest-path method, TSPM) in triangular (2D) or tetrahedral (3D) cell model and a linearized inversion solver (referred to as damped minimum norms and constrained least squares problem solved using the conjugate gradient method, DMNCLS-CG) to formulate a simultaneous travel time inversion method for updating both velocity and reflector geometry by using multiphase arrival times. In the triangular/tetrahedral cells, we deduced the partial derivative of velocity variation with respective to the depth change of reflector. The numerical simulation results show that the computational accuracy can be tuned to a high precision in forward modeling and the irregular velocity anomaly and reflector geometry can be accurately captured in the simultaneous inversion, because the triangular/tetrahedral cell can be easily used to stitch the irregular topography or subsurface interface.

Solution of Volterra and Fredholm Classes of Equations via Triangular Orthogonal Function (A Combination of Right Hand Triangular Function and Left Hand Triangular Function) and Hybrid Orthogonal Function (A Combination of Sample Hold Function and Right Hand Triangular Function)

NASA Astrophysics Data System (ADS)

Mukhopadhyay, Anirban; Ganguly, Anindita; Chatterjee, Saumya Deep

2018-04-01

In this paper the authors have dealt with seven kinds of non-linear Volterra and Fredholm classes of equations. The authors have formulated an algorithm for solving the aforementioned equation types via Hybrid Function (HF) and Triangular Function (TF) piecewise-linear orthogonal approach. In this approach the authors have reduced integral equation or integro-differential equation into equivalent system of simultaneous non-linear equation and have employed either Newton's method or Broyden's method to solve the simultaneous non-linear equations. The authors have calculated the L2-norm error and the max-norm error for both HF and TF method for each kind of equations. Through the illustrated examples, the authors have shown that the HF based algorithm produces stable result, on the contrary TF-computational method yields either stable, anomalous or unstable results.

Logical spin-filtering in a triangular network of quantum nanorings with a Rashba spin-orbit interaction

NASA Astrophysics Data System (ADS)

Dehghan, E.; Sanavi Khoshnoud, D.; Naeimi, A. S.

2018-01-01

The spin-resolved electron transport through a triangular network of quantum nanorings is studied in the presence of Rashba spin-orbit interaction (RSOI) and a magnetic flux using quantum waveguide theory. This study illustrates that, by tuning Rashba constant, magnetic flux and incoming electron energy, the triangular network of quantum rings can act as a perfect logical spin-filtering with high efficiency. By changing in the energy of incoming electron, at a proper value of the Rashba constant and magnetic flux, a reverse in the direction of spin can take place in the triangular network of quantum nanorings. Furthermore, the triangular network of quantum nanorings can be designed as a device and shows several simultaneous spintronic properties such as spin-splitter and spin-inverter. This spin-splitting is dependent on the energy of the incoming electron. Additionally, different polarizations can be achieved in the two outgoing leads from an originally incoming spin state that simulates a Stern-Gerlach apparatus.

Anisotropic magnetic properties of the triangular plane lattice material TmMgGaO 4

DOE PAGES

Cevallos, F. Alex; Stolze, Karoline; Kong, Tai; ...

2018-04-30

Here, the crystal growth, structure, and basic magnetic properties of TmMgGaO 4 are reported. The Tm ions are located in a planar triangular lattice consisting of distorted TmO6 octahedra, while the Mg and Ga atoms randomly occupy intermediary bilayers of M-O triangular bipyramids. The Tm ions are positionally disordered. The material displays an antiferromagnetic Curie Weiss theta of ~ -20 -25 K, with no clear ordering visible in the magnetic susceptibility down to 1.8 K; the structure and magnetic properties suggest that ordering of the magnetic moments is frustrated by both structural disorder and the triangular magnetic motif. Single crystalmore » magnetization measurements indicate that the magnetic properties are highly anisotropic, with large moments measured perpendicular to the triangular planes. At 2 K, a broad step-like feature is seen in the field-dependent magnetization perpendicular to the plane on applied field near 2 Tesla.« less

The picosecond structure of ultra-fast rogue waves

NASA Astrophysics Data System (ADS)

Klein, Avi; Shahal, Shir; Masri, Gilad; Duadi, Hamootal; Sulimani, Kfir; Lib, Ohad; Steinberg, Hadar; Kolpakov, Stanislav A.; Fridman, Moti

2018-02-01

We investigated ultrafast rogue waves in fiber lasers and found three different patterns of rogue waves: single- peaks, twin-peaks, and triple-peaks. The statistics of the different patterns as a function of the pump power of the laser reveals that the probability for all rogue waves patterns increase close to the laser threshold. We developed a numerical model which prove that the ultrafast rogue waves patterns result from both the polarization mode dispersion in the fiber and the non-instantaneous nature of the saturable absorber. This discovery reveals that there are three different types of rogue waves in fiber lasers: slow, fast, and ultrafast, which relate to three different time-scales and are governed by three different sets of equations: the laser rate equations, the nonlinear Schrodinger equation, and the saturable absorber equations, accordingly. This discovery is highly important for analyzing rogue waves and other extreme events in fiber lasers and can lead to realizing types of rogue waves which were not possible so far such as triangular rogue waves.

What is the correlation of in vivo wear and damage patterns with in vitro TDR motion response?

PubMed Central

Kurtz, Steven M.; Patwardhan, Avinash; MacDonald, Daniel; Ciccarelli, Lauren; van Ooij, André; Lorenz, Mark; Zindrick, Michael; O’Leary, Patrick; Isaza, Jorge; Ross, Raymond

2008-01-01

Background Context Total disc replacements (TDRs) have been used to reduce pain and preserve motion. However, the comparison of polyethylene wear following long-term implantation to those tested using an in vitro model had not yet been investigated. Purpose The purpose of this study was to correlate wear and damage patterns in retrieved TDRs with motion patterns observed in a clinically validated in vitro lumbar spine model. We also sought to determine whether one-sided wear and motion patterns were associated with greater in vivo wear. Study Design This two-part study combined the evaluation of retrieved total disc replacements with a biomechanical study using human lumbar spines. Patient Sample 38 CHARITÉ lumbar artificial discs were retrieved from 32 patients (24 female, 75%) after 7.3 years average implantation (range: 1.8 to 16.1y). The components were implanted at L2/L3 (n=1), L3/L4 (n=2), L4/L5 (n=20), and L5/S1 (n=15). All the implants were removed due to intractable back pain and/or facet degeneration. In addition, they were removed due to subsidence (n=10), anterior migration (n=3), core dislocation (n=2), lateral subluxation (n=1), endplate loosening (n = 2), and osteolysis (n=1). In parallel, 7 new implants were evaluated at L4-L5 and 13 implants at L5-S1 in an in vitro lumbar spine model. Outcome Measures Retrieval analysis included evaluation of clinical data, dimensional measurements and assessment of the extent and severity of PE surface damage mechanisms. In vitro testing involved the observation of motion patterns during physiological loading. Methods For the retrievals, each side of the PE core was independently analyzed at the rim and dome for the presence of machining marks, wear, and fracture. 35 cores were further analyzed using MicroCT to determine whether the wear was one-sided, or symmetrically distributed. For the in vitro study the new implants were tested under physiologic loads (flexion-extension with a compressive follower preload) using a validated cadaveric lumbar spine model. The center of the prosthesis was 2 mm posterior to the mid-point of the vertebral body endplate in mid-sagittal plane. Motion patterns of the in vitro-tested implants were tracked using sequential video-flouroscopy. Results Substantial variability was observed in the wear patterns of the retrievals. 15/35 retrieved cores (43%) displayed one-sided wear patterns. The median dome penetration was 0.2 mm (range: 0.06 to 0.9 mm) and the median penetration rate was 0.04 mm/y (range: 0.01 to 0.2 mm/y). No significant difference in penetration or penetration rate was observed between retrievals with one-sided and symmetric wear patterns (p >0.05). Significant correlations were observed between implantation time and penetration (rho = 0.46, p = 0.004) and penetration rate (rho = −0.48, p = 0.003). In the in vitro study, there was clear visual evidence of motion at both articulations in 8/20 implantations. In additional 8/20 cases, there was some evidence of motion at both articulations; however, the predominant motion occurred at the top articulation. In 4/20 implantations motion could be visually detected only at the top articulation. Core entrapment and pinching was observed in 7/20 cases as the segment was extended, and was associated with visual evidence of core bending or deformation in 5/20 cases. PMID:18317190

Cryogenic insulation development

NASA Technical Reports Server (NTRS)

Leonhard, K. E.

1972-01-01

Multilayer insulations for long term cryogenic storage are described. The development effort resulted in an insulation concept using lightweight radiation shields, separated by low conductive Dacron fiber tufts. The insulation is usually referred to as Superfloc. The fiber tufts are arranged in a triangular pattern and stand about .040 in. above the radiation shield base. Thermal and structural evaluation of Superfloc indicated that this material is a strong candidate for the development of high performance thermal protection systems because of its high strength, purge gas evacuation capability during boost, its density control and easy application to a tank.

Collocation of equilibria in gravitational field of triangular body via mass redistribution

NASA Astrophysics Data System (ADS)

Burov, Alexander A.; Guerman, Anna D.; Nikonov, Vasily I.

2018-05-01

We consider a gravitating system with triangular mass distribution that can be used as approximation of gravitational field for small irregular celestial bodies. In such system, the locations of equilibrium points, that is, the points where the gravitational forces are balanced, are analyzed. The goal is to find the mass distribution which provides equilibrium in a pre-assigned location near the triangular system, and to study the stability of this equilibrium.

Triangular arbitrage as an interaction among foreign exchange rates

NASA Astrophysics Data System (ADS)

Aiba, Yukihiro; Hatano, Naomichi; Takayasu, Hideki; Marumo, Kouhei; Shimizu, Tokiko

2002-07-01

We first show that there are in fact triangular arbitrage opportunities in the spot foreign exchange markets, analyzing the time dependence of the yen-dollar rate, the dollar-euro rate and the yen-euro rate. Next, we propose a model of foreign exchange rates with an interaction. The model includes effects of triangular arbitrage transactions as an interaction among three rates. The model explains the actual data of the multiple foreign exchange rates well.

Connector design in a long-span-fixed dental prosthesis: a three-dimensional finite element analysis.

PubMed

Harshitha Gowda, B H; Satish Babu, C L

2013-01-01

The goal of every prosthetic management is to simulate nature and be in harmony with nature within the physiological limits. The occlusal forces on a fixed dental prosthesis are transmitted to the surrounding structures through pontics, connectors and retainers and more stresses are seen at the connector region. To analyze the stress patterns in cast and soldered connectors between the two pontics and between the retainer and pontic of a four unit fixed dental prosthesis on axial and non axial loading and also to observe and ascertain the need to modify the design of the rigid connectors. Subsequently four models each of cast and soldered connectors with cylindrical and triangular design, of dimension 3 × 4 mm and thickness 0.5 mm was designed for the study. The first premolar and second molar were considered as the abutments and 2 nd premolar and 1 st molar as the pontics. The analysis was done using ANSYS version 8.0 software and by placing axial and non-axial load of 40 Newtons each. Von Misses stresses were observed at the connector region between the two pontics, especially in the cervical region. The cylindrical cast connectors showed less stress in comparison to triangular design and the difference in the stress distribution of cast and soldered connectors were marginal. The occlusal forces on a fixed dental prosthesis are transmitted to the surrounding structures through pontics, connectors and retainers with maximum stresses concentrated at the connectors. Hence this three-dimensional finite element analysis study investigated stress distribution in a four unit posterior fixed dental prosthesis, having cylindrical and triangular connector designs.

Ground penetrating radar for underground sensing in agriculture: a review

NASA Astrophysics Data System (ADS)

Liu, Xiuwei; Dong, Xuejun; Leskovar, Daniel I.

2016-10-01

Belowground properties strongly affect agricultural productivity. Traditional methods for quantifying belowground properties are destructive, labor-intensive and pointbased. Ground penetrating radar can provide non-invasive, areal, and repeatable underground measurements. This article reviews the application of ground penetrating radar for soil and root measurements and discusses potential approaches to overcome challenges facing ground penetrating radar-based sensing in agriculture, especially for soil physical characteristics and crop root measurements. Though advanced data-analysis has been developed for ground penetrating radar-based sensing of soil moisture and soil clay content in civil engineering and geosciences, it has not been used widely in agricultural research. Also, past studies using ground penetrating radar in root research have been focused mainly on coarse root measurement. Currently, it is difficult to measure individual crop roots directly using ground penetrating radar, but it is possible to sense root cohorts within a soil volume grid as a functional constituent modifying bulk soil dielectric permittivity. Alternatively, ground penetrating radarbased sensing of soil water content, soil nutrition and texture can be utilized to inversely estimate root development by coupling soil water flow modeling with the seasonality of plant root growth patterns. Further benefits of ground penetrating radar applications in agriculture rely on the knowledge, discovery, and integration among differing disciplines adapted to research in agricultural management.

Cusp repair in aortic valve reconstruction: does the technique affect stability?

PubMed

Aicher, Diana; Langer, Frank; Adam, Oliver; Tscholl, Dietmar; Lausberg, Henning; Schäfers, Hans-Joachim

2007-12-01

Cusp prolapse may be an isolated cause of aortic regurgitation or may exist in conjunction with dilatation of the proximal aorta. Prolapse can be corrected by central plication, triangular resection, or pericardial patch implantation. We retrospectively analyzed our results with these techniques. From October 1995 to December 2006, 604 patients (aged 3-86 years) underwent aortic valve repair. Cusp prolapse was found in 427 patients (246 tricuspid, 181 bicuspid). Prolapse was corrected by central plication (n = 275) or triangular resection (n = 80). A pericardial patch was implanted for pre-existing cusp defects or after excision of calcium (n = 72). One cusp was repaired in 198 patients; the remaining patients underwent repair of 2 (n = 189) or 3 cusps (n = 40). In 102 patients more than one technique was used, and the patients were allocated to the group of the assumedly more complex repair (central plication < triangular resection < pericardial patch plasty). Cumulative follow-up was 1238 patient-years (mean 35 +/- 27 months). Hospital mortality was 2.6% (11/427). Actuarial freedom from aortic regurgitation of grade II or more at 5 years was 92% (central plication), 90% (triangular resection), and 90% (pericardial patch plasty). Thirteen patients were reoperated on, with prolapse as the most common reason for failure (n = 7); 6 underwent re-repair. Freedom from reoperation at 5 years was 95% (central plication), 94% (triangular resection), and 94% (pericardial patch plasty). Freedom from valve replacement at 5 years was 97% (central plication), 99% (triangular resection), and 98% (pericardial patch plasty). In aortic valve repair, cusp prolapse can be treated reliably by central plication. In the presence of more complex disease, triangular resection or pericardial patch plasty may be used without compromising midterm durability.

Dependence of the L-Mode scrape-off layer power fall-off length on the upper triangularity in TCV

NASA Astrophysics Data System (ADS)

Faitsch, M.; Maurizio, R.; Gallo, A.; Coda, S.; Eich, T.; Labit, B.; Merle, A.; Reimerdes, H.; Sieglin, B.; Theiler, C.; the Eurofusion MST1 Team; the TCV Team

2018-04-01

This paper reports on experimental observations on TCV with a scan in upper triangularity {δ }up}, including negative triangularity, focusing on the power fall-off length {λ }{{q}} in L-Mode. The upper triangularity is scanned from -0.28 to 0.47. Smaller {λ }{{q}}out} is measured at the outer divertor target for decreasing {δ }up} together with higher edge temperature {T}{{e},{edge}} leading to increased confinement. This effect is observed for both magnetic drift directions for discharges in deuterium and helium. In helium larger {λ }{{q}} values are observed compared to deuterium. The power fall-off length at the inner divertor target {λ }{{q}}in} has a non-monotonic behaviour with changing triangularity. The largest values are around {δ }up}=0. The ratio {λ }{{q}}in}/{λ }{{q}}out} increases for decreasing {δ }up} for positive triangularity and is approximately constant for negative triangularity. {λ }{{q}}out} is compared to available scaling laws. Partial agreement is only observed for a scaling law containing a proxy for {T}{{e},{edge}} at ASDEX Upgrade (Sieglin 2016 Plasma Phys. Control. Fusion 58 055015). Extending this scaling to TCV and using {T}{{e},{edge}} at {ρ }pol}=0.95 suggests that {λ }{{q}}out} is independent of machine size {λ }{{q}}{{L} - {Mode}} ({mm}) = 165\\cdot {B}pol}{({{T}})}-0.66\\cdot A{({{u}})}-0.15\\cdot {T}{{e},{edge}}{({eV})}-0.93\\cdot R{({{m}})}-0.03. Possible explanations for smaller {λ }{{q}}out} for decreasing {δ }up} is a reduction in turbulence or a direct effect of increasing {T}{{e},{edge}}.

Modulation transfer function of a triangular pixel array detector.

PubMed

Karimzadeh, Ayatollah

2014-07-01

The modulation transfer function (MTF) is the main parameter that is used to evaluate image quality in electro-optical systems. Detector sampling MTF in most electro-optical systems determines the cutoff frequency of the system. The MTF of the detector depends on its pixel shape. In this work, we calculated the MTF of a detector with an equilateral triangular pixel shape. Some new results were found in deriving the MTF for the equilateral triangular pixel shape.

Galerkin finite difference Laplacian operators on isolated unstructured triangular meshes by linear combinations

NASA Technical Reports Server (NTRS)

Baumeister, Kenneth J.

1990-01-01

The Galerkin weighted residual technique using linear triangular weight functions is employed to develop finite difference formulae in Cartesian coordinates for the Laplacian operator on isolated unstructured triangular grids. The weighted residual coefficients associated with the weak formulation of the Laplacian operator along with linear combinations of the residual equations are used to develop the algorithm. The algorithm was tested for a wide variety of unstructured meshes and found to give satisfactory results.

Unitary Root Music and Unitary Music with Real-Valued Rank Revealing Triangular Factorization

DTIC Science & Technology

2010-06-01

AFRL-RY-WP-TP-2010-1213 UNITARY ROOT MUSIC AND UNITARY MUSIC WITH REAL-VALUED RANK REVEALING TRIANGULAR FACTORIZATION (Postprint) Nizar...DATES COVERED (From - To) June 2010 Journal Article Postprint 08 September 2006 – 31 August 2009 4. TITLE AND SUBTITLE UNITARY ROOT MUSIC AND...UNITARY MUSIC WITH REAL-VALUED RANK REVEALING TRIANGULAR FACTORIZATION (Postprint) 5a. CONTRACT NUMBER 5b. GRANT NUMBER FA8650-05-D-1912-0007 5c

Are the Color Gamuts of CRT and LCD Triangular? An Experimental Study

DTIC Science & Technology

2000-07-01

UNCLASSIFIED Defense Technical Information Center Compilation Part Notice ADPO113 31 TITLE: Are the Color Gamuts of CRT and LCD Triangular? An...ADP011297 thru ADP011332 UNCLASSIFIED Are the Color Gamuts of CRT and LCD Triangular? An Experimental Study Guan-wei Leea and Chao-hua Wenb aDepartment of...Tube) display. This study describes the difference of color gamuts in different luminance level and the accuracy of color between CRT and LCD. In the

Comparison of two-transsacral-screw fixation versus triangular osteosynthesis for transforaminal sacral fractures.

PubMed

Min, Kyong S; Zamorano, David P; Wahba, George M; Garcia, Ivan; Bhatia, Nitin; Lee, Thay Q

2014-09-01

Transforaminal pelvic fractures are high-energy injuries that are translationally and rotationally unstable. This study compared the biomechanical stability of triangular osteosynthesis vs 2-transsacral-screw fixation in the repair of a transforaminal pelvic fracture model. A transforaminal fracture model was created in 10 cadaveric lumbopelvic specimens. Five of the specimens were stabilized with triangular osteosynthesis, which consisted of unilateral L5-to-ilium lumbopelvic fixation and ipsilateral iliosacral screw fixation. The remaining 5 were stabilized with a 2-transsacral-screw fixation technique that consisted of 2 transsacral screws inserted across S1. All specimens were loaded cyclically and then loaded to failure. Translation and rotation were measured using the MicroScribe 3D digitizing system (Revware Inc, Raleigh, North Carolina). The 2-transsacral-screw group showed significantly greater stiffness than the triangular osteosynthesis group (2-transsacral-screw group, 248.7 N/mm [standard deviation, 73.9]; triangular osteosynthesis group, 125.0 N/mm [standard deviation, 66.9]; P=.02); however, ultimate load and rotational stiffness were not statistically significant. Compared with triangular osteosynthesis fixation, the use of 2 transsacral screws provides a comparable biomechanical stability profile in both translation and rotation. This newly revised 2-transsacral-screw construct offers the traumatologist an alternative method of repair for vertical shear fractures that provides biplanar stability. It also offers the advantage of percutaneous placement in either the prone or supine position. Copyright 2014, SLACK Incorporated.

On the Use of the Beta Distribution in Probabilistic Resource Assessments

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

Olea, Ricardo A., E-mail: olea@usgs.gov

2011-12-15

The triangular distribution is a popular choice when it comes to modeling bounded continuous random variables. Its wide acceptance derives mostly from its simple analytic properties and the ease with which modelers can specify its three parameters through the extremes and the mode. On the negative side, hardly any real process follows a triangular distribution, which from the outset puts at a disadvantage any model employing triangular distributions. At a time when numerical techniques such as the Monte Carlo method are displacing analytic approaches in stochastic resource assessments, easy specification remains the most attractive characteristic of the triangular distribution. Themore » beta distribution is another continuous distribution defined within a finite interval offering wider flexibility in style of variation, thus allowing consideration of models in which the random variables closely follow the observed or expected styles of variation. Despite its more complex definition, generation of values following a beta distribution is as straightforward as generating values following a triangular distribution, leaving the selection of parameters as the main impediment to practically considering beta distributions. This contribution intends to promote the acceptance of the beta distribution by explaining its properties and offering several suggestions to facilitate the specification of its two shape parameters. In general, given the same distributional parameters, use of the beta distributions in stochastic modeling may yield significantly different results, yet better estimates, than the triangular distribution.« less

Multifrequency synthesis and extraction using square wave projection patterns for quantitative tissue imaging.

PubMed

Nadeau, Kyle P; Rice, Tyler B; Durkin, Anthony J; Tromberg, Bruce J

2015-11-01

We present a method for spatial frequency domain data acquisition utilizing a multifrequency synthesis and extraction (MSE) method and binary square wave projection patterns. By illuminating a sample with square wave patterns, multiple spatial frequency components are simultaneously attenuated and can be extracted to determine optical property and depth information. Additionally, binary patterns are projected faster than sinusoids typically used in spatial frequency domain imaging (SFDI), allowing for short (millisecond or less) camera exposure times, and data acquisition speeds an order of magnitude or more greater than conventional SFDI. In cases where sensitivity to superficial layers or scattering is important, the fundamental component from higher frequency square wave patterns can be used. When probing deeper layers, the fundamental and harmonic components from lower frequency square wave patterns can be used. We compared optical property and depth penetration results extracted using square waves to those obtained using sinusoidal patterns on an in vivo human forearm and absorbing tube phantom, respectively. Absorption and reduced scattering coefficient values agree with conventional SFDI to within 1% using both high frequency (fundamental) and low frequency (fundamental and harmonic) spatial frequencies. Depth penetration reflectance values also agree to within 1% of conventional SFDI.

Multifrequency synthesis and extraction using square wave projection patterns for quantitative tissue imaging

PubMed Central

Nadeau, Kyle P.; Rice, Tyler B.; Durkin, Anthony J.; Tromberg, Bruce J.

2015-01-01

Abstract. We present a method for spatial frequency domain data acquisition utilizing a multifrequency synthesis and extraction (MSE) method and binary square wave projection patterns. By illuminating a sample with square wave patterns, multiple spatial frequency components are simultaneously attenuated and can be extracted to determine optical property and depth information. Additionally, binary patterns are projected faster than sinusoids typically used in spatial frequency domain imaging (SFDI), allowing for short (millisecond or less) camera exposure times, and data acquisition speeds an order of magnitude or more greater than conventional SFDI. In cases where sensitivity to superficial layers or scattering is important, the fundamental component from higher frequency square wave patterns can be used. When probing deeper layers, the fundamental and harmonic components from lower frequency square wave patterns can be used. We compared optical property and depth penetration results extracted using square waves to those obtained using sinusoidal patterns on an in vivo human forearm and absorbing tube phantom, respectively. Absorption and reduced scattering coefficient values agree with conventional SFDI to within 1% using both high frequency (fundamental) and low frequency (fundamental and harmonic) spatial frequencies. Depth penetration reflectance values also agree to within 1% of conventional SFDI. PMID:26524682

Coupling effect of topological states and Chern insulators in two-dimensional triangular lattices

NASA Astrophysics Data System (ADS)

Zhang, Jiayong; Zhao, Bao; Xue, Yang; Zhou, Tong; Yang, Zhongqin

2018-03-01

We investigate topological states of two-dimensional (2D) triangular lattices with multiorbitals. Tight-binding model calculations of a 2D triangular lattice based on px and py orbitals exhibit very interesting doubly degenerate energy points at different positions (Γ and K /K' ) in momentum space, with quadratic non-Dirac and linear Dirac band dispersions, respectively. Counterintuitively, the system shows a global topologically trivial rather than nontrivial state with consideration of spin-orbit coupling due to the "destructive interference effect" between the topological states at the Γ and K /K' points. The topologically nontrivial state can emerge by introducing another set of triangular lattices to the system (bitriangular lattices) due to the breakdown of the interference effect. With first-principles calculations, we predict an intrinsic Chern insulating behavior (quantum anomalous Hall effect) in a family of the 2D triangular lattice metal-organic framework of Co(C21N3H15) (TPyB-Co) from this scheme. Our results provide a different path and theoretical guidance for the search for and design of new 2D topological quantum materials.

Optimal parallel solution of sparse triangular systems

NASA Technical Reports Server (NTRS)

Alvarado, Fernando L.; Schreiber, Robert

1990-01-01

A method for the parallel solution of triangular sets of equations is described that is appropriate when there are many right-handed sides. By preprocessing, the method can reduce the number of parallel steps required to solve Lx = b compared to parallel forward or backsolve. Applications are to iterative solvers with triangular preconditioners, to structural analysis, or to power systems applications, where there may be many right-handed sides (not all available a priori). The inverse of L is represented as a product of sparse triangular factors. The problem is to find a factored representation of this inverse of L with the smallest number of factors (or partitions), subject to the requirement that no new nonzero elements be created in the formation of these inverse factors. A method from an earlier reference is shown to solve this problem. This method is improved upon by constructing a permutation of the rows and columns of L that preserves triangularity and allow for the best possible such partition. A number of practical examples and algorithmic details are presented. The parallelism attainable is illustrated by means of elimination trees and clique trees.

Three-dimensional periodic dielectric structures having photonic Dirac points

DOEpatents

Bravo-Abad, Jorge; Joannopoulos, John D.; Soljacic, Marin

2015-06-02

The dielectric, three-dimensional photonic materials disclosed herein feature Dirac-like dispersion in quasi-two-dimensional systems. Embodiments include a face-centered cubic (fcc) structure formed by alternating layers of dielectric rods and dielectric slabs patterned with holes on respective triangular lattices. This fcc structure also includes a defect layer, which may comprise either dielectric rods or a dielectric slab with patterned with holes. This defect layer introduces Dirac cone dispersion into the fcc structure's photonic band structure. Examples of these fcc structures enable enhancement of the spontaneous emission coupling efficiency (the .beta.-factor) over large areas, contrary to the conventional wisdom that the .beta.-factor degrades as the system's size increases. These results enable large-area, low-threshold lasers; single-photon sources; quantum information processing devices; and energy harvesting systems.

Modelling and simulation of parallel triangular triple quantum dots (TTQD) by using SIMON 2.0

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

Fathany, Maulana Yusuf, E-mail: myfathany@gmail.com; Fuada, Syifaul, E-mail: fsyifaul@gmail.com; Lawu, Braham Lawas, E-mail: bram-labs@rocketmail.com

2016-04-19

This research presents analysis of modeling on Parallel Triple Quantum Dots (TQD) by using SIMON (SIMulation Of Nano-structures). Single Electron Transistor (SET) is used as the basic concept of modeling. We design the structure of Parallel TQD by metal material with triangular geometry model, it is called by Triangular Triple Quantum Dots (TTQD). We simulate it with several scenarios using different parameters; such as different value of capacitance, various gate voltage, and different thermal condition.

Dynamic hysteresis behaviors in the kinetic Ising system on triangular lattice

NASA Astrophysics Data System (ADS)

Kantar, Ersin; Ertaş, Mehmet

2018-04-01

We studied dynamic hysteresis behaviors of the spin-1 Blume-Capel (BC) model in a triangular lattice by means of the effective-field theory (EFT) with correlations and using Glauber-type stochastic dynamics. The effects of the exchange interaction (J), crystal field (D), temperature (T) and oscillating frequency (w) on the hysteresis behaviors of the BC model in a triangular lattice are investigated in detail. Results are compared with some other dynamic studies and quantitatively good agreement is found.

MR imaging of the traumatic triangular fibrocartilaginous complex tear

PubMed Central

Griffith, James F.; Fung, Cindy S. Y.; Lee, Ryan K. L.; Tong, Cina S. L.; Wong, Clara W. Y.; Tse, Wing Lim; Ho, Pak Cheong

2017-01-01

Triangular fibrocartilage complex is a major stabilizer of the distal radioulnar joint (DRUJ). However, triangular fibrocartilage complex (TFCC) tear is difficult to be diagnosed on MRI for its intrinsic small and thin structure with complex anatomy. The purpose of this article is to review the anatomy of TFCC, state of art MRI imaging technique, normal appearance and features of tear on MRI according to the Palmar’s classification. Atypical tear and limitations of MRI in diagnosis of TFCC tear are also discussed. PMID:28932701

Structural evolution of a granular medium during simultaneous penetration

NASA Astrophysics Data System (ADS)

González-Gutiérrez, Jorge; Carreón, Yojana J. P.; Moctezuma, R. E.

2018-01-01

Typically, fluidized beds are granular systems composed of solid particles through which a fluid flows. They are relevant to a wide variety of disciplines such as physics, chemistry, engineering, among others. Generally, the fluidized beds are characterized by different flow regimes such as particulate, bubbling, slugging, turbulent, fast fluidization, and pneumatic conveying. Here, we report the experimental study of the structural evolution of a granular system due to simultaneous penetration of intruders in the presence of an upward airflow. We found that the granular medium evolves from the static state to the turbulent regime showing the coexistence of three regions in different flow regimes. Interestingly, the cooperative dynamic of intruders correlate with the formation of such regions. As a non-invasive method, we use lacunarity and fractal dimension to quantitatively describe the patterns arising within the system during the different stages of the penetration process. Finally, we found that our results would allow us to relate the evolution of the visual patterns appearing in the process with different physical properties of the system.

Reduction of polyspermic penetration using biomimetic microfluidic technology during in vitro fertilization.

PubMed

Clark, Sherrie G; Haubert, Kathyrn; Beebe, David J; Ferguson, C Edward; Wheeler, Matthew B

2005-11-01

Efforts to improve the in vitro embryo production process in pigs have included modifying culture medium and number of spermatozoa inseminated in order to reduce the incidence of polyspermy. Polyspermy is a pathological condition which results in aberrant embryonic development. The microchannels are designed to more closely mimic the function of the oviduct and create a flow pattern of spermatozoa past the oocytes similar to the pattern in the oviduct. In vitro fertilization of porcine oocytes in the microchannels has produced a higher incidence of monospermic penetration (p<0.05) as compared to the oocytes fertilized in the traditional microdrop system with comparable penetration and male pronucleus formation rates. Additionally, cleavage rates of the embryos as well as development to the blastocyst stage are similar. Here we demonstrate that the biomimetic microchannel in vitro fertilization system can reduce polyspermy and, therefore, increase the number of potentially viable embryos without reducing the overall in vitro production efficiency.

Opening the Door on Triangular Numbers

ERIC Educational Resources Information Center

McMartin, Kimberley; McMaster, Heather

2016-01-01

As an alternative to looking solely at linear functions, a three-lesson learning progression developed for Year 6 students that incorporates triangular numbers to develop children's algebraic thinking is described and evaluated.

Reconstruction of the lateral tibia plateau fracture with a third triangular support screw: A biomechanical study.

PubMed

Moran, Eduardo; Zderic, Ivan; Klos, Kajetan; Simons, Paul; Triana, Miguel; Richards, R Geoff; Gueorguiev, Boyko; Lenz, Mark

2017-10-01

Split fractures of the lateral tibia plateau in young patients with good bone quality are commonly treated using two minimally invasive percutaneous lag screws, followed by unloading of the knee joint. Improved stability could be achieved with the use of a third screw inserted either in the jail-technique fashion or with a triangular support screw configuration. The aim of this study was to investigate under cyclic loading the compliance and endurance of the triangular support fixation in comparison with the standard two lag-screw fixation and the jail technique. Lateral split fractures of type AO/OTA 41-B1 were created on 21 synthetic tibiae and subsequently fixed with one of the following three techniques for seven specimens: standard fixation by inserting two partially threaded 6.5 mm cannulated lag screws parallel to each other and orthogonal to the fracture plane; triangular support fixation-standard fixation with one additional support screw at the distal end of the fracture at 30° proximal inclination; and jail fixation-standard fixation with one additional orthogonal support screw inserted in the medial nonfractured part of the bone. Mechanical testing was performed under progressively increasing cyclic compression loading. Fragment displacement was registered via triggered radiographic imaging. Mean construct compliance was 3.847 × 10 -3  mm/N [standard deviation (SD) 0.784] for standard fixation, 3.838 × 10 -3  mm/N (SD 0.242) for triangular fixation, and 3.563 × 10 -3  mm/N (SD 0.383) for jail fixation, with no significant differences between the groups ( p  = 0.525). The mean numbers of cycles to 2 mm fragment dislocation, defined as a failure criterion, were 12,384 (SD 2267) for standard fixation, 17,708 (SD 2193) for triangular fixation, and 14,629 (SD 5194) for jail fixation. Triangular fixation revealed significantly longer endurance than the standard one ( p  = 0.047). Triangular support fixation enhanced interfragmentary stability at the ultimate stage of dynamic loading. However, the level of improvement seems to be limited and may not legitimate the intervention with an additional third screw.

Fabrication of Multscale Fractal-Like Structures by Controlling Fluid Interface Instability

PubMed Central

Islam, Tanveer ul; Gandhi, Prasanna S.

2016-01-01

Nature, in quest for the best designs has shaped its vital systems into fractal geometries. Effectual way of spontaneous fabrication of scalable, ordered fractal-like structures by controlling Saffman-Taylor instability in a lifted Hele-Shaw cell is deployed here. In lifted Hele-Shaw cell uncontrolled penetration of low-viscosity fluid into its high-viscosity counterpart is known to develop irregular, non-repeatable, normally short-lived, branched patterns. We propose and characterize experimentally anisotropies in a form of spatially distributed pits on the cell plates to control initiation and further penetration of non-splitting fingers. The proposed control over shielding mechanism yields recipes for fabrication of families of ordered fractal-like patterns of multiple generations. As an example, we demonstrate and characterize fabrication of a Cayley tree fractal-like pattern. The patterns, in addition, are retained permanently by employing UV/thermally curable fluids. The proposed technique thus establishes solid foundation for bio-mimicking natural structures spanning multiple-scales for scientific and engineering use. PMID:27849003

Fabrication of Multscale Fractal-Like Structures by Controlling Fluid Interface Instability

NASA Astrophysics Data System (ADS)

Islam, Tanveer Ul; Gandhi, Prasanna S.

2016-11-01

Nature, in quest for the best designs has shaped its vital systems into fractal geometries. Effectual way of spontaneous fabrication of scalable, ordered fractal-like structures by controlling Saffman-Taylor instability in a lifted Hele-Shaw cell is deployed here. In lifted Hele-Shaw cell uncontrolled penetration of low-viscosity fluid into its high-viscosity counterpart is known to develop irregular, non-repeatable, normally short-lived, branched patterns. We propose and characterize experimentally anisotropies in a form of spatially distributed pits on the cell plates to control initiation and further penetration of non-splitting fingers. The proposed control over shielding mechanism yields recipes for fabrication of families of ordered fractal-like patterns of multiple generations. As an example, we demonstrate and characterize fabrication of a Cayley tree fractal-like pattern. The patterns, in addition, are retained permanently by employing UV/thermally curable fluids. The proposed technique thus establishes solid foundation for bio-mimicking natural structures spanning multiple-scales for scientific and engineering use.

Effectiveness of Rotation-free Triangular and Quadrilateral Shell Elements in Sheet-metal Forming Simulations

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

Brunet, M.; Sabourin, F.

2005-08-05

This paper is concerned with the effectiveness of triangular 3-node shell element without rotational d.o.f. and the extension to a new 4-node quadrilateral shell element called S4 with only 3 translational degrees of freedom per node and one-point integration. The curvatures are computed resorting to the surrounding elements. Extension from rotation-free triangular element to a quadrilateral element requires internal curvatures in order to avoid singular bending stiffness. Two numerical examples with regular and irregular meshes are performed to show the convergence and accuracy. Deep-drawing of a box, spring-back analysis of a U-shape strip sheet and the crash simulation of amore » beam-box complete the demonstration of the bending capabilities of the proposed rotation-free triangular and quadrilateral elements.« less

On the Use of the Beta Distribution in Probabilistic Resource Assessments

USGS Publications Warehouse

Olea, R.A.

2011-01-01

The triangular distribution is a popular choice when it comes to modeling bounded continuous random variables. Its wide acceptance derives mostly from its simple analytic properties and the ease with which modelers can specify its three parameters through the extremes and the mode. On the negative side, hardly any real process follows a triangular distribution, which from the outset puts at a disadvantage any model employing triangular distributions. At a time when numerical techniques such as the Monte Carlo method are displacing analytic approaches in stochastic resource assessments, easy specification remains the most attractive characteristic of the triangular distribution. The beta distribution is another continuous distribution defined within a finite interval offering wider flexibility in style of variation, thus allowing consideration of models in which the random variables closely follow the observed or expected styles of variation. Despite its more complex definition, generation of values following a beta distribution is as straightforward as generating values following a triangular distribution, leaving the selection of parameters as the main impediment to practically considering beta distributions. This contribution intends to promote the acceptance of the beta distribution by explaining its properties and offering several suggestions to facilitate the specification of its two shape parameters. In general, given the same distributional parameters, use of the beta distributions in stochastic modeling may yield significantly different results, yet better estimates, than the triangular distribution. ?? 2011 International Association for Mathematical Geology (outside the USA).

The orientation distribution of tunneling-related quantities

NASA Astrophysics Data System (ADS)

Seif, W. M.; Refaie, A. I.; Botros, M. M.

2018-03-01

In the nuclear tunneling processes involving deformed nuclei, most of the tunneling-related quantities depend on the relative orientations of the participating nuclei. In the presence of different multipole deformations, we study the variation of a few relevant quantities for the α-decay and the sub-barrier fusion processes, in an orientation degree of freedom. The knocking frequency and the penetration probability are evaluated within the Wentzel-Kramers-Brillouin approximation. The interaction potential is calculated with Skyrme-type nucleon-nucleon interaction. We found that the width of the potential pocket, the Coulomb barrier radius, the penetration probability, the α-decay width, and the fusion cross-section follow consistently the orientation-angle variation of the radius of the deformed nucleus. The orientation distribution patterns of the pocket width, the barrier radius, the logarithms of the penetrability, the decay width, and the fusion cross-section are found to be highly analogous to pattern of the deformed-nucleus radius. The curve patterns of the orientation angle distributions of the internal pocket depth, the Coulomb barrier height and width, as well as the knocking frequency simulate inversely the variation of the deformed nucleus radius. The predicted orientation behaviors will be of a special interest in predicting the optimum orientations for the tunneling processes.

7 CFR 810.1403 - Basis of determination.

Code of Federal Regulations, 2012 CFR

2012-01-01

... broken kernels, and foreign material that will pass through a 1.98 mm (5/64 inches) triangular-hole sieve... (5/64 inches) triangular-hole sieve. [57 FR 58971, Dec. 14, 1992] Grades and Grade Requirements ...

7 CFR 810.1403 - Basis of determination.

Code of Federal Regulations, 2014 CFR

2014-01-01

... broken kernels, and foreign material that will pass through a 1.98 mm (5/64 inches) triangular-hole sieve... (5/64 inches) triangular-hole sieve. [57 FR 58971, Dec. 14, 1992] Grades and Grade Requirements ...

7 CFR 810.1403 - Basis of determination.

Code of Federal Regulations, 2011 CFR

2011-01-01

... broken kernels, and foreign material that will pass through a 1.98 mm (5/64 inches) triangular-hole sieve... (5/64 inches) triangular-hole sieve. [57 FR 58971, Dec. 14, 1992] Grades and Grade Requirements ...

7 CFR 810.1403 - Basis of determination.

Code of Federal Regulations, 2013 CFR

2013-01-01

... broken kernels, and foreign material that will pass through a 1.98 mm (5/64 inches) triangular-hole sieve... (5/64 inches) triangular-hole sieve. [57 FR 58971, Dec. 14, 1992] Grades and Grade Requirements ...

The Inland Penetration of Atmospheric Rivers over Western North America: A Lagrangian Analysis

NASA Astrophysics Data System (ADS)

Rutz, J. J.; Steenburgh, W. J.; Ralph, F. M.

2014-12-01

Although atmospheric rivers (ARs) typically weaken following landfall, those that penetrate inland can contribute to heavy precipitation and high-impact weather within the interior of western North America. In this paper, we examine the evolution of ARs over western North America using trajectories released at 950 and 700 hPa within cool-season ARs along the Pacific coast. These trajectories are classified as coastal decaying, inland penetrating, or interior penetrating based on whether they remain within an AR upon reaching selected transects over western North America. Interior-penetrating AR trajectories most frequently make landfall along the Oregon coast, but the greatest fraction of landfalling AR trajectories that eventually penetrate into the interior is found along the Baja Peninsula. In contrast, interior-penetrating trajectories rarely traverse the southern "high" Sierra. At landfall, interior-penetrating trajectories are associated with a more amplified flow pattern, more southwesterly (vs. westerly) flow along the Pacific coast, and larger water vapor transport (qu). The larger initial qu of interior-penetrating trajectories is due primarily to larger initial water vapor (q) and wind speed (u) for those initiated at 950 and 700 hPa, respectively. Inland- and interior-penetrating AR trajectories maintain large qu over the interior due partially to increases in u that offset decreases in q, particularly in the vicinity of topographical barriers. Therefore, synoptic conditions and trajectory pathways favoring larger initial qu at the coast, limited water vapor depletion by orographic precipitation, and increases in u over the interior are keys to differentiating interior-penetrating from coastal-decaying AR trajectories.

The comparative impact of the market penetration of energy-efficient measures: A sensitivity analysis of its impact on minority households

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

Bozinovich, L.V.; Poyer, D.A.; Anderson, J.L.

1993-12-01

A sensitivity study was made of the potential market penetration of residential energy efficiency as energy service ratio (ESR) improvements occurred in minority households, by age of house. The study followed a Minority Energy Assessment Model analysis of the National Energy Strategy projections of household energy consumption and prices, with majority, black, and Hispanic subgroup divisions. Electricity and total energy consumption and expenditure patterns were evaluated when the households` ESR improvement followed a logistic negative growth (i.e., market penetration) path. Earlier occurrence of ESR improvements meant greater discounted savings over the 22-year period.

Software for C1 interpolation

NASA Technical Reports Server (NTRS)

Lawson, C. L.

1977-01-01

The problem of mathematically defining a smooth surface, passing through a finite set of given points is studied. Literature relating to the problem is briefly reviewed. An algorithm is described that first constructs a triangular grid in the (x,y) domain, and first partial derivatives at the modal points are estimated. Interpolation in the triangular cells using a method that gives C sup.1 continuity overall is examined. Performance of software implementing the algorithm is discussed. Theoretical results are presented that provide valuable guidance in the development of algorithms for constructing triangular grids.

Scaffolded DNA origami of a DNA tetrahedron molecular container.

PubMed

Ke, Yonggang; Sharma, Jaswinder; Liu, Minghui; Jahn, Kasper; Liu, Yan; Yan, Hao

2009-06-01

We describe a strategy of scaffolded DNA origami to design and construct 3D molecular cages of tetrahedron geometry with inside volume closed by triangular faces. Each edge of the triangular face is approximately 54 nm in dimension. The estimated total external volume and the internal cavity of the triangular pyramid are about 1.8 x 10(-23) and 1.5 x 10(-23) m(3), respectively. Correct formation of the tetrahedron DNA cage was verified by gel electrophoresis, atomic force microscopy, transmission electron microscopy, and dynamic light scattering techniques.

Nonlinear interaction and wave breaking with a submerged porous structure

NASA Astrophysics Data System (ADS)

Hsieh, Chih-Min; Sau, Amalendu; Hwang, Robert R.; Yang, W. C.

2016-12-01

Numerical simulations are performed to investigate interactive velocity, streamline, turbulent kinetic energy, and vorticity perturbations in the near-field of a submerged offshore porous triangular structure, as Stokes waves of different heights pass through. The wave-structure interaction and free-surface breaking for the investigated flow situations are established based on solutions of 2D Reynolds Averaged Navier-Stokes equations in a Cartesian grid in combination with K-ɛ turbulent closure and the volume of fluid methodology. The accuracy and stability of the adopted model are ascertained by extensive comparisons of computed data with the existing experimental and theoretical findings and through efficient predictions of the internal physical kinetics. Simulations unfold "clockwise" and "anticlockwise" rotation of fluid below the trough and the crest of the viscous waves, and the penetrated wave energy creates systematic flow perturbation in the porous body. The interfacial growths of the turbulent kinetic energy and the vorticity appear phenomenal, around the apex of the immersed structure, and enhanced significantly following wave breaking. Different values of porosity parameter and two non-porous cases have been examined in combination with varied incident wave height to reveal/analyze the nonlinear flow behavior in regard to local spectral amplification and phase-plane signatures. The evolution of leading harmonics of the undulating free-surface and the vertical velocity exhibits dominating roles of the first and the second modes in inducing the nonlinearity in the post-breaking near-field that penetrates well below the surface layer. The study further suggests the existence of a critical porosity that can substantially enhance the wave-shoaling and interface breaking.

On the divergence of triangular and eccentric spherical sums of double Fourier series

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

Karagulyan, G A

We construct a continuous function on the torus with almost everywhere divergent triangular sums of double Fourier series. We also prove an analogous theorem for eccentric spherical sums. Bibliography: 14 titles.

Chemical lift-off of (11-22) semipolar GaN using periodic triangular cavities

NASA Astrophysics Data System (ADS)

Jeon, Dae-Woo; Lee, Seung-Jae; Jeong, Tak; Baek, Jong Hyeob; Park, Jae-Woo; Jang, Lee-Woon; Kim, Myoung; Lee, In-Hwan; Ju, Jin-Woo

2012-01-01

Chemical lift-off of (11-22) semipolar GaN using triangular cavities was investigated. The (11-22) semipolar GaN was grown using epitaxial lateral overgrowth by metal-organic chemical vapor deposition on m-plane sapphire, in such a way as to keep N terminated surface of c-plane GaN exposed in the cavities. After regrowing 300 μm thick (11-22) semipolar GaN by hydride vapor phase epitaxy for a free-standing (11-22) semipolar GaN substrate, the triangular cavities of the templates were chemically etched in molten KOH. The (000-2) plane in the triangular cavities can be etched in the [0002] direction with the high lateral etching rate of 196 μm/min. The resulting free-standing (11-22) semipolar GaN substrate was confirmed to be strain-free by the Raman analysis.

An approach to decision-making with triangular fuzzy reciprocal preference relations and its application

NASA Astrophysics Data System (ADS)

Meng, Fanyong

2018-02-01

Triangular fuzzy reciprocal preference relations (TFRPRs) are powerful tools to denoting decision-makers' fuzzy judgments, which permit the decision-makers to apply triangular fuzzy ratio rather than real numbers to express their judgements. Consistency analysis is one of the most crucial issues in preference relations that can guarantee the reasonable ranking order. However, all previous consistency concepts cannot well address this type of preference relations. Based on the operational laws on triangular fuzzy numbers, this paper introduces an additive consistency concept for TFRPRs by using quasi TFRPRs, which can be seen as a natural extension of the crisp case. Using this consistency concept, models to judging the additive consistency of TFRPRs and to estimating missing values in complete TFRPRs are constructed. Then, an algorithm to decision-making with TFRPRs is developed. Finally, two numerical examples are offered to illustrate the application of the proposed procedure, and comparison analysis is performed.

Polarizing beam splitter of deep-etched triangular-groove fused-silica gratings.

PubMed

Zheng, Jiangjun; Zhou, Changhe; Feng, Jijun; Wang, Bo

2008-07-15

We investigated the use of a deep-etched fused-silica grating with triangular-shaped grooves as a highly efficient polarizing beam splitter (PBS). A triangular-groove PBS grating is designed at a wavelength of 1550 nm to be used in optical communication. When it is illuminated in Littrow mounting, the transmitted TE- and TM-polarized waves are mainly diffracted in the minus-first and zeroth orders, respectively. The design condition is based on the average differences of the grating mode indices, which is verified by using rigorous coupled-wave analysis. The designed PBS grating is highly efficient over the C+L band range for both TE and TM polarizations (>97.68%). It is shown that such a triangular-groove PBS grating can exhibit a higher diffraction efficiency, a larger extinction ratio, and less reflection loss than the binary-phase fused-silica PBS grating.

Arrays of flow channels with heat transfer embedded in conducting walls

DOE PAGES

Bejan, A.; Almerbati, A.; Lorente, S.; ...

2016-04-20

Here we illustrate the free search for the optimal geometry of flow channel cross-sections that meet two objectives simultaneously: reduced resistances to heat transfer and fluid flow. The element cross section and the wall material are fixed, while the shape of the fluid flow opening, or the wetted perimeter is free to vary. Two element cross sections are considered, square and equilateral triangular. We find that the two objectives are best met when the solid wall thickness is uniform, i.e., when the wetted perimeters are square and triangular, respectively. In addition, we consider arrays of square elements and triangular elements,more » on the basis of equal mass flow rate per unit of array cross sectional area. The conclusion is that the array of triangular elements meets the two objectives better than the array of square elements.« less

A proposed mathematical model for sleep patterning.

PubMed

Lawder, R E

1984-01-01

The simple model of a ramp, intersecting a triangular waveform, yields results which conform with seven generalized observations of sleep patterning; including the progressive lengthening of 'rapid-eye-movement' (REM) sleep periods within near-constant REM/nonREM cycle periods. Predicted values of REM sleep time, and of Stage 3/4 nonREM sleep time, can be computed using the observed values of other parameters. The distributions of the actual REM and Stage 3/4 times relative to the predicted values were closer to normal than the distributions relative to simple 'best line' fits. It was found that sleep onset tends to occur at a particular moment in the individual subject's '90-min cycle' (the use of a solar time-scale masks this effect), which could account for a subject with a naturally short sleep/wake cycle synchronizing to a 24-h rhythm. A combined 'sleep control system' model offers quantitative simulation of the sleep patterning of endogenous depressives and, with a different perturbation, qualitative simulation of the symptoms of narcolepsy.

Distinct aggregation patterns and fluid porous phase in a 2D model for colloids with competitive interactions

NASA Astrophysics Data System (ADS)

Bordin, José Rafael

2018-04-01

In this paper we explore the self-assembly patterns in a two dimensional colloidal system using extensive Langevin Dynamics simulations. The pair potential proposed to model the competitive interaction have a short range length scale between first neighbors and a second characteristic length scale between third neighbors. We investigate how the temperature and colloidal density will affect the assembled morphologies. The potential shows aggregate patterns similar to observed in previous works, as clusters, stripes and porous phase. Nevertheless, we observe at high densities and temperatures a porous mesophase with a high mobility, which we name fluid porous phase, while at lower temperatures the porous structure is rigid. triangular packing was observed for the colloids and pores in both solid and fluid porous phases. Our results show that the porous structure is well defined for a large range of temperature and density, and that the fluid porous phase is a consequence of the competitive interaction and the random forces from the Langevin Dynamics.

Ultrasonographic Diagnosis of Biliary Atresia Based on a Decision-Making Tree Model.

PubMed

Lee, So Mi; Cheon, Jung-Eun; Choi, Young Hun; Kim, Woo Sun; Cho, Hyun-Hae; Cho, Hyun-Hye; Kim, In-One; You, Sun Kyoung

2015-01-01

To assess the diagnostic value of various ultrasound (US) findings and to make a decision-tree model for US diagnosis of biliary atresia (BA). From March 2008 to January 2014, the following US findings were retrospectively evaluated in 100 infants with cholestatic jaundice (BA, n = 46; non-BA, n = 54): length and morphology of the gallbladder, triangular cord thickness, hepatic artery and portal vein diameters, and visualization of the common bile duct. Logistic regression analyses were performed to determine the features that would be useful in predicting BA. Conditional inference tree analysis was used to generate a decision-making tree for classifying patients into the BA or non-BA groups. Multivariate logistic regression analysis showed that abnormal gallbladder morphology and greater triangular cord thickness were significant predictors of BA (p = 0.003 and 0.001; adjusted odds ratio: 345.6 and 65.6, respectively). In the decision-making tree using conditional inference tree analysis, gallbladder morphology and triangular cord thickness (optimal cutoff value of triangular cord thickness, 3.4 mm) were also selected as significant discriminators for differential diagnosis of BA, and gallbladder morphology was the first discriminator. The diagnostic performance of the decision-making tree was excellent, with sensitivity of 100% (46/46), specificity of 94.4% (51/54), and overall accuracy of 97% (97/100). Abnormal gallbladder morphology and greater triangular cord thickness (> 3.4 mm) were the most useful predictors of BA on US. We suggest that the gallbladder morphology should be evaluated first and that triangular cord thickness should be evaluated subsequently in cases with normal gallbladder morphology.

Prevalence of triangular fibrocartilage complex abnormalities regardless of symptoms rise with age: systematic review and pooled analysis.

PubMed

Chan, Jimmy J; Teunis, Teun; Ring, David

2014-12-01

Triangular fibrocartilage complex abnormalities seem to be more common with age, but the degree to which this is so, and the degree to which the presence of an abnormality is associated with symptoms, are topics of controversy. We wished to perform a systematic review to determine the prevalence of triangular fibrocartilage complex abnormalities, and to determine if the prevalence of abnormalities are greater with increasing age. In addition, we stratified age groups based on symptoms. We searched MEDLINE, EMBASE, and the Cochrane Library through August 15, 2013. Studies that reported triangular fibrocartilage complex abnormalities by age were included. Fifteen studies including 977 wrists met our criteria and reported a total of 368 (38%) triangular fibrocartilage complex abnormalities. Eight studies included symptomatic patients; the remainder studied cadavers (six studies) or asymptomatic volunteers (one study). Patients were divided into four age groups (< 30, 30-49, 50-69, and 70 years and older) for pooled analysis, comparing the proportions of patients with and without abnormalities between groups using chi-square analysis. We also evaluated the proportions after stratifying each age group by symptoms. Overall, the prevalence of triangular fibrocartilage complex abnormalities increased with age, from 27% (80/301) in patients younger than 30 years to 49% (130/265) in patients 70 years and older (p < 0.001), odds ratio (OR), 2.7, 95% CI, 1.9-3.8 (p < 0.001). In asymptomatic patients, triangular fibrocartilage complex prevalence abnormality increased from 15% (24/159) to 49% (129/263) in the same age groups (p < 0.001), OR, 5.4, 95% CI, 3.3-8.9 (p < 0.001). For symptomatic patients prevalence ranged from 39% (56/142) to 70% (14/20) in patients between 50 and 69 years old (p < 0.034), OR, 3.6, 95% CI, 1.3-9.9 (p < 0.014). Triangular fibrocartilage complex abnormalities are common in symptomatic and asymptomatic wrists, and they are increasingly common with age. As in all situations where abnormalities are so common that they may be incidental, we need (1) a reliable and accurate method for determining whether these abnormalities are the cause of symptoms; and (2) evidence that treatment of these abnormalities improves symptoms better than placebo. Level III, prognostic study. See the Instructions for Authors for a complete description of levels of evidence.

Evolution patterns and parameter regimes in edge localized modes on the National Spherical Torus Experiment

DOE Data Explorer

Smith, D. R. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Bell, R. E. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Podesta, M. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Smith, D. R. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Fonck, R. J. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); McKee, G. R. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Diallo, A. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Kaye, S. M. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); LeBlanc, B. P. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Sabbagh, S. A. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)

2015-09-01

We implement unsupervised machine learning techniques to identify characteristic evolution patterns and associated parameter regimes in edge localized mode (ELM) events observed on the National Spherical Torus Experiment. Multi-channel, localized measurements spanning the pedestal region capture the complex evolution patterns of ELM events on Alfven timescales. Some ELM events are active for less than 100~microsec, but others persist for up to 1~ms. Also, some ELM events exhibit a single dominant perturbation, but others are oscillatory. Clustering calculations with time-series similarity metrics indicate the ELM database contains at least two and possibly three groups of ELMs with similar evolution patterns. The identified ELM groups trigger similar stored energy loss, but the groups occupy distinct parameter regimes for ELM-relevant quantities like plasma current, triangularity, and pedestal height. Notably, the pedestal electron pressure gradient is not an effective parameter for distinguishing the ELM groups, but the ELM groups segregate in terms of electron density gradient and electron temperature gradient. The ELM evolution patterns and corresponding parameter regimes can shape the formulation or validation of nonlinear ELM models. Finally, the techniques and results demonstrate an application of unsupervised machine learning at a data-rich fusion facility.

Global Research Patterns on Ground Penetrating Radar (GPR)

NASA Astrophysics Data System (ADS)

Gizzi, Fabrizio Terenzio; Leucci, Giovanni

2018-05-01

The article deals with the analysis of worldwide research patterns concerning ground penetrating radar (GPR) during 1995-2014. To do this, the Thomson Reuters' Science Citation Index Expanded (SCI-EXPANDED) and the Social Sciences Citation Index accessed via the Web of Science Core Collection were the two bibliographic databases taken as a reference. We pay attention to the document typology and language, the publication trend and citations, the subject categories and journals, the collaborations between authors, the productivity of the authors, the most cited articles, the countries and the institutions involved, and other hot issues. Concerning the main research subfields involving GPR use, there were five, physical-mathematical, sedimentological-stratigraphical, civil engineering/engineering geology/cultural heritage, hydrological (HD), and glaciological (GL), subfields.

Surface analyses of composites exposed to the space environment on LDEF

NASA Technical Reports Server (NTRS)

Mallon, Joseph J.; Uht, Joseph C.; Hemminger, Carol S.

1993-01-01

A series of surface analyses on carbon fiber/poly(arylacetylene) (PAA) matrix composites that were exposed to the space environment on the Long Duration Exposure Facility (LDEF) satellite were conducted. These composite panels were arranged in pairs on both the leading edge and trailing edge of LDEF. None of the composites were catastrophically damaged by nearly six years of exposure to the space environment. Composites on the leading edge exhibited from 25 to 125 microns of surface erosion, but trailing edge panels exhibited no physical appearance changes due to exposure. Scanning electron microscopy (SEM) was used to show that the erosion morphology on the leading edge samples was dominated by crevasses parallel to the fibers with triangular cross sections 10 to 100 microns in depth. The edges of the crevasses were well defined and penetrated through both matrix and fiber. The data suggest that the carbon fibers are playing an important role in crevasse initiation and/or enlargement, and in the overall erosion rate of the composite. X-ray photoelectron spectroscopy (XPS) and energy dispersive x-ray spectroscopy (EDS) results showed contamination from in-flight sources of silicone.

Self characterization of a coded aperture array for neutron source imaging

NASA Astrophysics Data System (ADS)

Volegov, P. L.; Danly, C. R.; Fittinghoff, D. N.; Guler, N.; Merrill, F. E.; Wilde, C. H.

2014-12-01

The neutron imaging system at the National Ignition Facility (NIF) is an important diagnostic tool for measuring the two-dimensional size and shape of the neutrons produced in the burning deuterium-tritium plasma during the stagnation stage of inertial confinement fusion implosions. Since the neutron source is small (˜100 μm) and neutrons are deeply penetrating (>3 cm) in all materials, the apertures used to achieve the desired 10-μm resolution are 20-cm long, triangular tapers machined in gold foils. These gold foils are stacked to form an array of 20 apertures for pinhole imaging and three apertures for penumbral imaging. These apertures must be precisely aligned to accurately place the field of view of each aperture at the design location, or the location of the field of view for each aperture must be measured. In this paper we present a new technique that has been developed for the measurement and characterization of the precise location of each aperture in the array. We present the detailed algorithms used for this characterization and the results of reconstructed sources from inertial confinement fusion implosion experiments at NIF.

Characterisation and optimisation of Ground Penetrating Radar antennas

NASA Astrophysics Data System (ADS)

Warren, Craig; Giannopoulos, Antonios

2014-05-01

Research on the characterisation and optimisation of Ground Penetrating Radar (GPR) antennas will be presented as part of COST Action TU1208 "Civil Engineering Applications of Ground Penetrating Radar". This work falls within the remit of Working Group 1 - "Novel GPR instrumentation" which focuses on the design of innovative GPR equipment for Civil Engineering (CE) applications, on the building of prototypes and on the testing and optimisation of new systems. The diversity of applications of GPR has meant there are a number of different GPR antenna designs available to the end-user as well as those being used in the research community. The type and size of a GPR antenna is usually dependent on the application, e.g. low frequency antennas, which are physically larger, are used where significant depth of penetration is important, whereas high frequency antennas, which are physically smaller, are used where less penetration and better resolution are required. Understanding how energy is transmitted and received by a particular GPR antenna has many benefits: it could lead to more informed usage of the antenna in GPR surveys; improvements in antenna design; and better interpretation of GPR signal returns from the ground/structure. The radiation characteristics of a particular antenna are usually investigated by studying the radiation patterns and directivity. For GPR antennas it is also important to study these characteristics when the antenna is in different environments that would typically be encountered in GPR surveys. In this work Finite-Difference Time-Domain (FDTD) numerical models of GPR antennas have been developed. These antenna models replicate all the detailed geometry and main components of the real antennas. The models are representative of typical high-frequency, high-resolution GPR antennas primarily used in CE for the evaluation of structural features in concrete: the location of rebar, conduits, and post-tensioned cables, as well as the estimation of material thickness on bridge decks and pavements. Radiation patterns obtained using the antenna models as well as physical measurements have been used to investigate the radiation characteristics of high-frequency GPR antennas. Studies were conducted with homogeneous materials of different dielectric constants (Er=3, 10, 30, & 72) and at a range of observation distances. The first objective was to compare, using the FDTD antenna model, 'traditional' transmitted field patterns with field patterns obtained using responses from a target spaced at regular intervals around the circumference of a circle, i.e. received energy. Our initial results show, for the same dielectric and observation distance, E- and H-field patterns obtained using the received energy approach have a significantly narrower main lobe than the traditional transmitted patterns. This raises the question of which approach is more beneficial for the characterisation of GPR antennas, and hence better interpretation of GPR responses. The second objective was to compare modelled field patterns with measured patterns obtained from a commercial high-frequency GPR antenna using the received energy approach. The measurements were made in different oil-in-water emulsions which were used to simulate materials with different permittivities and conductivities. Initial comparisons of the measured and modelled data show a very good correlation, which validates use of the antenna model for further studies.

3D face analysis by using Mesh-LBP feature

NASA Astrophysics Data System (ADS)

Wang, Haoyu; Yang, Fumeng; Zhang, Yuming; Wu, Congzhong

2017-11-01

Objective: Face Recognition is one of the widely application of image processing. Corresponding two-dimensional limitations, such as the pose and illumination changes, to a certain extent restricted its accurate rate and further development. How to overcome the pose and illumination changes and the effects of self-occlusion is the research hotspot and difficulty, also attracting more and more domestic and foreign experts and scholars to study it. 3D face recognition fusing shape and texture descriptors has become a very promising research direction. Method: Our paper presents a 3D point cloud based on mesh local binary pattern grid (Mesh-LBP), then feature extraction for 3D face recognition by fusing shape and texture descriptors. 3D Mesh-LBP not only retains the integrity of the 3D geometry, is also reduces the need for recognition process of normalization steps, because the triangle Mesh-LBP descriptor is calculated on 3D grid. On the other hand, in view of multi-modal consistency in face recognition advantage, construction of LBP can fusing shape and texture information on Triangular Mesh. In this paper, some of the operators used to extract Mesh-LBP, Such as the normal vectors of the triangle each face and vertex, the gaussian curvature, the mean curvature, laplace operator and so on. Conclusion: First, Kinect devices obtain 3D point cloud face, after the pretreatment and normalization, then transform it into triangular grid, grid local binary pattern feature extraction from face key significant parts of face. For each local face, calculate its Mesh-LBP feature with Gaussian curvature, mean curvature laplace operator and so on. Experiments on the our research database, change the method is robust and high recognition accuracy.

DETAIL VIEW OF LARGE BORE HOLE, SHOWING TRIANGULAR SHAPE FORMED ...

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

DETAIL VIEW OF LARGE BORE HOLE, SHOWING TRIANGULAR SHAPE FORMED BY CHISEL METHOD OF DRILLING - Granite Hill Plantation, Quarry No. 3, South side of State Route 16, 1.3 miles northeast east of Sparta, Sparta, Hancock County, GA

Theoretical characteristics in supersonic flow of two types of control surfaces on triangular wings

NASA Technical Reports Server (NTRS)

Tucker, Warren A; Nelson, Robert L

1949-01-01

Methods based on the linearized theory for supersonic flow were used to find the characteristics of two types of control surfaces on thin triangular wings. The first type, the constant-chord partial-span flap, was considered to extend either outboard from the center of the wing or inboard from the wing tip. The second type, the full-triangular-tip flap, was treated only for the case in which the Mach number component normal to the leading edge is supersonic. For each type, expressions were found for the lift, rolling-moment, pitching-moment, and hinge-moment characteristics.

Stability of triangular points in the elliptic restricted three-body problem with oblateness up to zonal harmonic J4 of both primaries

NASA Astrophysics Data System (ADS)

Singh, Jagadish; Tyokyaa, Richard K.

2016-10-01

In this paper, we study the locations and stability of triangular points in the elliptic restricted three-body problem when both primaries are taken as oblate spheroids with oblateness up to J4. The positions of the triangular points are seen to be affected by oblateness of the primaries and the eccentricity of their orbits. The triangular points are conditionally stable for 0<μ<μc0<μ<μc and unstable for μc≤μ≤12μc≤μ≤12, where μcμc is the critical mass parameter depending on the oblateness coefficients J2iJ2i (i =1,2) and the eccentricity of the orbits. We further observe that both coefficients J2 and J4, semi-major axis and the eccentricity have destabilizing tendencies resulting in a decrease in the size of the region of stability with an increase in the parameters involved. Knowing that, in general, the triangular equilibrium points are stable for 0<μ<μc0<μ<μc, in particular systems (Alpha Centauri, X1X1 Bootis, Sirius and Kruger 60) this does not hold and such points are unstable.

Revision of the genus Cuvierina Boas, 1886 based on integrative taxonomic data, including the description of a new species from the Pacific Ocean (Gastropoda, Thecosomata)

PubMed Central

Burridge, Alice K.; Janssen, Arie W.; Peijnenburg, Katja T.C.A.

2016-01-01

Abstract Shelled pteropods (Gastropoda, Thecosomata, Euthecosomata) are a group of holoplanktonic gastropods that occur predominantly in the surface layers of the world’s oceans. Accurate species identifications are essential for tracking changes in species assemblages of planktonic gastropods, because different species are expected to have different sensitivities to ocean changes. The genus Cuvierina has a worldwide warm water distribution pattern between ~36°N and ~39°S. Based on an integrative taxonomic approach combining morphometric, genetic, and biogeographic information, the two subgenera of Cuvierina, Cuvierina s. str. and Urceolarica, are rejected. A new species is introduced: Cuvierina tsudai sp. n., which has to date been considered the same species as Cuvierina pacifica. Cuvierina tsudai sp. n. is endemic to the Pacific Ocean and is characterised by a shell height of 7.2-8.0 mm, a moderately cylindrical shell shape, the absence of micro-ornamentation and a triangular aperture. Cuvierina pacifica is restricted to the centre of the oligotrophic southern Pacific gyre, has a shell height of 6.6-8.5 mm, a more cylindrical shell shape, no micro-ornamentation and a less triangular aperture than Cuvierina tsudai sp. n. PMID:27829786

Selective MBE growth of hexagonal networks of trapezoidal and triangular GaAs nanowires on patterned (1 1 1)B substrates

NASA Astrophysics Data System (ADS)

Tamai, Isao; Hasegawa, Hideki

2007-04-01

As a combination of novel hardware architecture and novel system architecture for future ultrahigh-density III-V nanodevice LSIs, the authors' group has recently proposed a hexagonal binary decision diagram (BDD) quantum circuit approach where gate-controlled path switching BDD node devices for a single or few electrons are laid out on a hexagonal nanowire network to realize a logic function. In this paper, attempts are made to establish a method to grow highly dense hexagonal nanowire networks for future BDD circuits by selective molecular beam epitaxy (MBE) on (1 1 1)B substrates. The (1 1 1)B orientation is suitable for BDD architecture because of the basic three-fold symmetry of the BDD node device. The growth experiments showed complex evolution of the cross-sectional structures, and it was explained in terms of kinetics determining facet boundaries. Straight arrays of triangular nanowires with 60 nm base width as well as hexagonal arrays of trapezoidal nanowires with a node density of 7.5×10 6 cm -2 were successfully grown with the aid of computer simulation. The result shows feasibility of growing high-density hexagonal networks of GaAs nanowires with precise control of the shape and size.

POMESH - DIFFRACTION ANALYSIS OF REFLECTOR ANTENNAS

NASA Technical Reports Server (NTRS)

Hodges, R. E.

1994-01-01

POMESH is a computer program capable of predicting the performance of reflector antennas. Both far field pattern and gain calculations are performed using the Physical Optics (PO) approximation of the equivalent surface currents. POMESH is primarily intended for relatively small reflectors. It is useful in situations where the surface is described by irregular data that must be interpolated and for cases where the surface derivatives are not known. This method is flexible and robust and also supports near field calculations. Because of the near field computation ability, this computational engine is quite useful for subreflector computations. The program is constructed in a highly modular form so that it may be readily adapted to perform tasks other than the one that is explicitly described here. Since the computationally intensive portions of the algorithm are simple loops, the program can be easily adapted to take advantage of vector processor and parallel architectures. In POMESH the reflector is represented as a piecewise planar surface comprised of triangular regions known as facets. A uniform physical optics (PO) current is assumed to exist on each triangular facet. Then, the PO integral on a facet is approximated by the product of the PO current value at the center and the area of the triangle. In this way, the PO integral over the reflector surface is reduced to a summation of the contribution from each triangular facet. The source horn, or feed, that illuminates the subreflector is approximated by a linear combination of plane patterns. POMESH contains three polarization pattern definitions for the feed; a linear x-polarized element, linear y-polarized element, and a circular polarized element. If a more general feed pattern is required, it is a simple matter to replace the subroutine that implements the pattern definitions. POMESH obtains information necessary to specify the coordinate systems, location of other data files, and parameters of the desired calculation from a user provided data file. A numerical description of the principle plane patterns of the source horn must also be provided. The program is supplied with an analytically defined parabolic reflector surface. However, it is a simple matter to replace it with a user defined reflector surface. Output is given in the form of a data stream to the terminal; a summary of the parameters used in the computation and some sample results in a file; and a data file of the results of the pattern calculations suitable for plotting. POMESH is written in FORTRAN 77 for execution on CRAY series computers running UNICOS. With minor modifications, it has also been successfully implemented on a Sun4 series computer running SunOS, a DEC VAX series computer running VMS, and an IBM PC series computer running OS/2. It requires 2.5Mb of RAM under SunOS 4.1.1, 2.5Mb of RAM under VMS 5-4.3, and 2.5Mb of RAM under OS/2. The OS/2 version requires the Lahey F77L compiler. The standard distribution medium for this program is one 5.25 inch 360K MS-DOS format diskette. It is also available on a .25 inch streaming magnetic tape cartridge in UNIX tar format and a 9-track 1600 BPI magnetic tape in DEC VAX FILES-11 format. POMESH was developed in 1989 and is a copyrighted work with all copyright vested in NASA. CRAY and UNICOS are registered trademarks of Cray Research, Inc. SunOS and Sun4 are trademarks of Sun Microsystems, Inc. DEC, DEC FILES-11, VAX and VMS are trademarks of Digital Equipment Corporation. IBM PC and OS/2 are registered trademarks of International Business Machines, Inc. UNIX is a registered trademark of Bell Laboratories.

Black Artists' Music Videos: Three Successful Strategies

ERIC Educational Resources Information Center

Peterson-Lewis, Sonja; Chennault, Shirley A.

1986-01-01

Identifies three successful self-presentational patterns used by black artists to penetrate the music television market. Discusses the historical relationship between minorities and the mass media. (MS)

Acoustic analysis of swallowing sounds: a new technique for assessing dysphagia.

PubMed

Santamato, Andrea; Panza, Francesco; Solfrizzi, Vincenzo; Russo, Anna; Frisardi, Vincenza; Megna, Marisa; Ranieri, Maurizio; Fiore, Pietro

2009-07-01

To perform acoustic analysis of swallowing sounds, using a microphone and a notebook computer system, in healthy subjects and patients with dysphagia affected by neurological diseases, testing the positive/negative predictive value of a pathological pattern of swallowing sounds for penetration/aspiration. Diagnostic test study, prospective, not blinded, with the penetration/aspiration evaluated by fibreoptic endoscopy of swallowing as criterion standard. Data from a previously recorded database of normal swallowing sounds for 60 healthy subjects according to gender, age, and bolus consistency was compared with those of 15 patients with dysphagia from a university hospital referral centre who were affected by various neurological diseases. Mean duration of the swallowing sounds and post-swallowing apnoea were recorded. Penetration/aspiration was verified by fibreoptic endoscopy of swallowing in all patients with dysphagia. The mean duration of swallowing sounds for a liquid bolus of 10 ml water was significantly different between patients with dysphagia and healthy patients. We also described patterns of swallowing sounds and tested the negative/positive predictive values of post-swallowing apnoea for penetration/aspiration verified by fibreoptic endoscopy of swallowing (sensitivity 0.67 (95% confidence interval 0.24-0.94); specificity 1.00 (95% confidence interval 0.56-1.00)). The proposed technique for recording and measuring swallowing sounds could be incorporated into the bedside evaluation, but it should not replace the use of more diagnostic and valuable measures.

Effect of Pore Size and Pore Connectivity on Unidirectional Capillary Penetration Kinetics in 3-D Porous Media using Direct Numerical Simulation

NASA Astrophysics Data System (ADS)

Fu, An; Palakurthi, Nikhil; Konangi, Santosh; Comer, Ken; Jog, Milind

2017-11-01

The physics of capillary flow is used widely in multiple fields. Lucas-Washburn equation is developed by using a single pore-sized capillary tube with continuous pore connection. Although this equation has been extended to describe the penetration kinetics into porous medium, multiple studies have indicated L-W does not accurately predict flow patterns in real porous media. In this study, the penetration kinetics including the effect of pore size and pore connectivity will be closely examined since they are expected to be the key factors effecting the penetration process. The Liquid wicking process is studied from a converging and diverging capillary tube to the complex virtual 3-D porous structures with Direct Numerical Simulation (DNS) using the Volume-Of-Fluid (VOF) method within the OpenFOAM CFD Solver. Additionally Porous Medium properties such as Permeability (k) , Tortuosity (τ) will be also analyzed.

Grid cells form a global representation of connected environments.

PubMed

Carpenter, Francis; Manson, Daniel; Jeffery, Kate; Burgess, Neil; Barry, Caswell

2015-05-04

The firing patterns of grid cells in medial entorhinal cortex (mEC) and associated brain areas form triangular arrays that tessellate the environment [1, 2] and maintain constant spatial offsets to each other between environments [3, 4]. These cells are thought to provide an efficient metric for navigation in large-scale space [5-8]. However, an accurate and universal metric requires grid cell firing patterns to uniformly cover the space to be navigated, in contrast to recent demonstrations that environmental features such as boundaries can distort [9-11] and fragment [12] grid patterns. To establish whether grid firing is determined by local environmental cues, or provides a coherent global representation, we recorded mEC grid cells in rats foraging in an environment containing two perceptually identical compartments connected via a corridor. During initial exposures to the multicompartment environment, grid firing patterns were dominated by local environmental cues, replicating between the two compartments. However, with prolonged experience, grid cell firing patterns formed a single, continuous representation that spanned both compartments. Thus, we provide the first evidence that in a complex environment, grid cell firing can form the coherent global pattern necessary for them to act as a metric capable of supporting large-scale spatial navigation. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Grid Cells Form a Global Representation of Connected Environments

PubMed Central

Carpenter, Francis; Manson, Daniel; Jeffery, Kate; Burgess, Neil; Barry, Caswell

2015-01-01

Summary The firing patterns of grid cells in medial entorhinal cortex (mEC) and associated brain areas form triangular arrays that tessellate the environment [1, 2] and maintain constant spatial offsets to each other between environments [3, 4]. These cells are thought to provide an efficient metric for navigation in large-scale space [5–8]. However, an accurate and universal metric requires grid cell firing patterns to uniformly cover the space to be navigated, in contrast to recent demonstrations that environmental features such as boundaries can distort [9–11] and fragment [12] grid patterns. To establish whether grid firing is determined by local environmental cues, or provides a coherent global representation, we recorded mEC grid cells in rats foraging in an environment containing two perceptually identical compartments connected via a corridor. During initial exposures to the multicompartment environment, grid firing patterns were dominated by local environmental cues, replicating between the two compartments. However, with prolonged experience, grid cell firing patterns formed a single, continuous representation that spanned both compartments. Thus, we provide the first evidence that in a complex environment, grid cell firing can form the coherent global pattern necessary for them to act as a metric capable of supporting large-scale spatial navigation. PMID:25913404

Effects of riparian forest removal on the trophic dynamics of a Neotropical stream fish assemblage.

PubMed

Lobón-Cerviá, J; Mazzoni, R; Rezende, C F

2016-07-01

The effects of riparian forest removal on a neotropical stream fish assemblage were assessed in the Mata Atlântica. Fish assemblage structure and fish feeding patterns were quantified at three sites along a pristine-to-deforested gradient in a Serra do Mar stream: (1) a pristine site fully covered by canopy with no light penetration and transparent waters, (2) an intermediate site with partially removed forest and (3) a fully removed forest site with no canopy and full light penetration where siltation and turbid waters predominate. Fish assemblage structure, fish densities and their feeding patterns differed widely among sites. Whilst the same five fish species occurred at the three sites, forest removal favoured the occurrence of sediment-tolerant iliophagous benthic species at the deforested site. At the pristine site, invertebrate prey predominated in water column fish diet and feeding overlap among species was low. Severe shifts in the feeding patterns were noticed in both deforested sites. Invertebrates were replaced by detritus, organic matter and algae at both sites and feeding overlap increased markedly. The overwhelming feeding adaptability of these neotropical fishes appeared capable of buffering the deleterious effects of forest removal on stream quality in terms of increased light penetration, siltation and water turbidity. Forest cutting in this Mata Atlântica stream clearly caused strong functional changes associated with forest clearance through important modifications in the assemblage organization and trophic patterns of the main species, but did not eliminate species. © 2016 The Fisheries Society of the British Isles.

Interpreting medium ring canonical conformers by a triangular plane tessellation of the macrocycle

NASA Astrophysics Data System (ADS)

Khalili, Pegah; Barnett, Christopher B.; Naidoo, Kevin J.

2013-05-01

Cyclic conformational coordinates are essential for the distinction of molecular ring conformers as the use of Cremer-Pople coordinates have illustrated for five- and six-membered rings. Here, by tessellating medium rings into triangular planes and using the relative angles made between triangular planes we are able to assign macrocyclic pucker conformations into canonical pucker conformers such as chairs, boats, etc. We show that the definition is straightforward compared with other methods popularly used for small rings and that it is computationally simple to implement for complex macrocyclic rings. These cyclic conformational coordinates directly couple to the motion of individual nodes of a ring. Therefore, they are useful for correlating the physical properties of macrocycles with their ring pucker and measuring the dynamic ring conformational behavior. We illustrate the triangular tessellation, assignment, and pucker analysis on 7- and 8-membered rings. Sets of canonical states are given for cycloheptane and cyclooctane that have been previously experimentally analysed.

Arthroscopic assisted tendon reconstruction for triangular fibrocartilage complex irreparable tears.

PubMed

Luchetti, R; Atzei, A

2017-05-01

We report our 11-year experience of performing arthroscopically assisted triangular fibrocartilage complex reconstruction in the treatment of chronic distal radio-ulnar joint instability resulting from irreparable triangular fibrocartilage complex injuries. Eleven patients were treated. Three skin incisions were made in order to create radial and ulna tunnels for passage of the tendon graft, which is used to reconstruct the dorsal and palmar radio-ulnar ligaments, under fluoroscopic and arthroscopic guidance. At a mean follow-up of 68 months all but one had a stable distal radio-ulnar joint. Pain and grip strength, Mayo wrist score, Disability of the Arm Hand and Shoulder and patient-rated wrist and hand evaluation scores improved. The ranges of forearm rotation remained largely unchanged. Complications included an early tendon graft tear, two late-onset graft ruptures, one ulna styloid fracture during surgery and persistent wrist discomfort during forearm rotation requiring tendon graft revision in one case. An arthroscopic assisted approach for triangular fibrocartilage complex reconstruction appears safe and produces comparable results with the open technique. IV.

Topological magnon bands and unconventional thermal Hall effect on the frustrated honeycomb and bilayer triangular lattice.

PubMed

Owerre, S A

2017-09-27

In the conventional ferromagnetic systems, topological magnon bands and thermal Hall effect are due to the Dzyaloshinskii-Moriya interaction (DMI). In principle, however, the DMI is either negligible or it is not allowed by symmetry in some quantum magnets. Therefore, we expect that topological magnon features will not be present in those systems. In addition, quantum magnets on the triangular-lattice are not expected to possess topological features as the DMI or spin-chirality cancels out due to equal and opposite contributions from adjacent triangles. Here, however, we predict that the isomorphic frustrated honeycomb-lattice and bilayer triangular-lattice antiferromagnetic system will exhibit topological magnon bands and topological thermal Hall effect in the absence of an intrinsic DMI. These unconventional topological magnon features are present as a result of magnetic-field-induced non-coplanar spin configurations with nonzero scalar spin chirality. The relevance of the results to realistic bilayer triangular antiferromagnetic materials are discussed.

Efficient generation of discontinuity-preserving adaptive triangulations from range images.

PubMed

Garcia, Miguel Angel; Sappa, Angel Domingo

2004-10-01

This paper presents an efficient technique for generating adaptive triangular meshes from range images. The algorithm consists of two stages. First, a user-defined number of points is adaptively sampled from the given range image. Those points are chosen by taking into account the surface shapes represented in the range image in such a way that points tend to group in areas of high curvature and to disperse in low-variation regions. This selection process is done through a noniterative, inherently parallel algorithm in order to gain efficiency. Once the image has been subsampled, the second stage applies a two and one half-dimensional Delaunay triangulation to obtain an initial triangular mesh. To favor the preservation of surface and orientation discontinuities (jump and crease edges) present in the original range image, the aforementioned triangular mesh is iteratively modified by applying an efficient edge flipping technique. Results with real range images show accurate triangular approximations of the given range images with low processing times.

On Modeling and Analysis of MIMO Wireless Mesh Networks with Triangular Overlay Topology

DOE PAGES

Cao, Zhanmao; Wu, Chase Q.; Zhang, Yuanping; ...

2015-01-01

Multiple input multiple output (MIMO) wireless mesh networks (WMNs) aim to provide the last-mile broadband wireless access to the Internet. Along with the algorithmic development for WMNs, some fundamental mathematical problems also emerge in various aspects such as routing, scheduling, and channel assignment, all of which require an effective mathematical model and rigorous analysis of network properties. In this paper, we propose to employ Cartesian product of graphs (CPG) as a multichannel modeling approach and explore a set of unique properties of triangular WMNs. In each layer of CPG with a single channel, we design a node coordinate scheme thatmore » retains the symmetric property of triangular meshes and develop a function for the assignment of node identity numbers based on their coordinates. We also derive a necessary-sufficient condition for interference-free links and combinatorial formulas to determine the number of the shortest paths for channel realization in triangular WMNs.« less

Ising antiferromagnet on a finite triangular lattice with free boundary conditions

NASA Astrophysics Data System (ADS)

Kim, Seung-Yeon

2015-11-01

The exact integer values for the density of states of the Ising model on an equilateral triangular lattice with free boundary conditions are evaluated up to L = 24 spins on a side for the first time by using the microcanonical transfer matrix. The total number of states is 2 N s = 2300 ≈ 2.037 × 1090 for L = 24, where N s = L( L+1)/2 is the number of spins. Classifying all 2300 spin states according to their energy values is an enormous work. From the density of states, the exact partition function zeros in the complex temperature plane of the triangular-lattice Ising model are evaluated. Using the density of states and the partition function zeros, we investigate the properties of the triangularlattice Ising antiferromagnet. The scaling behavior of the ground-state entropy and the form of the correlation length at T = 0 are studied for the triangular-lattice Ising antiferromagnet with free boundary conditions. Also, the scaling behavior of the Fisher edge singularity is investigated.

Triangular flow of negative pions emitted in PbAu collisions at √{sNN} = 17.3 GeV

NASA Astrophysics Data System (ADS)

Adamová, D.; Agakichiev, G.; Andronic, A.; Antończyk, D.; Appelshäuser, H.; Belaga, V.; Bielčíková, J.; Braun-Munzinger, P.; Busch, O.; Cherlin, A.; Damjanović, S.; Dietel, T.; Dietrich, L.; Drees, A.; Dubitzky, W.; Esumi, S. I.; Filimonov, K.; Fomenko, K.; Fraenkel, Z.; Garabatos, C.; Glässel, P.; Hering, G.; Holeczek, J.; Kalisky, M.; Karpenko, Iu.; Krobath, G.; Kushpil, V.; Maas, A.; Marín, A.; Milošević, J.; Miśkowiec, D.; Panebrattsev, Y.; Petchenova, O.; Petráček, V.; Radomski, S.; Rak, J.; Ravinovich, I.; Rehak, P.; Sako, H.; Schmitz, W.; Schuchmann, S.; Sedykh, S.; Shimansky, S.; Stachel, J.; Šumbera, M.; Tilsner, H.; Tserruya, I.; Tsiledakis, G.; Wessels, J. P.; Wienold, T.; Wurm, J. P.; Yurevich, S.; Yurevich, V.

2017-01-01

Differential triangular flow, v3 (pT), of negative pions is measured at √{sNN} = 17.3 GeV around midrapidity by the CERES/NA45 experiment at CERN in central PbAu collisions in the range 0-30% with a mean centrality of 5.5%. This is the first measurement as a function of transverse momentum of the triangular flow at SPS energies. The pT range extends from about 0.05 GeV/c to more than 2 GeV/c. The triangular flow magnitude, corrected for the HBT effects, is smaller by a factor of about 2 than the one measured by the PHENIX experiment at RHIC and the ALICE experiment at the LHC. Within the analyzed range of central collisions no significant centrality dependence is observed. The data are found to be well described by a viscous hydrodynamic calculation combined with an UrQMD cascade model for the late stages.

Effects of holding time during cooling and of type of package on plasma membrane integrity, motility and in vitro oocyte penetration ability of frozen-thawed boar spermatozoa.

PubMed

Eriksson, B M; Vazquez, J M; Martinez, E A; Roca, J; Lucas, X; Rodriguez-Martinez, H

2001-05-01

The effect of a prolonged holding time (HT) during cooling on plasma membrane integrity (PMI), motility and in vitro oocyte penetration ability of boar spermatozoa frozen-thawed in different types of package was investigated. Boar semen was frozen in a split-sample design using 3 different HTs (3, 10 and 20 h) during cooling and three different types of freezing package: Maxi-straws, Medium-straws and FlatPacks. Assessment of PMI (SYBR-14 and propidium iodide, fluorescence microscopy) and sperm motility (visually and with CASA) was done during cooling (at 32 degrees C, 15 degrees C, 5 degrees C) and post-thaw (PT). The in vitro oocyte penetration ability of the spermatozoa was tested only PT, using a homologous in vitro penetration assay (hIVP). During cooling the HTs used had no significant (p<0.05) effect on either PMI or percentage of motile spermatozoa Post-thaw PMI was significantly higher (p<0.05) for 10 h and 20 h HT compared with 3 h, and the percentage of motile spermatozoa decreased significantly with 20 h HT as opposed to 3 h and 10 h. Regarding the freezing packages, the FlatPacks and Maxi-straws yielded significantly more PMI than did the Medium-straws (p<0.05). Post-thaw motility was significantly higher for FlatPacks than for straws, in terms of both percentage motile spermatozoa, and sperm velocity and lateral head displacement (LHD). The hIVP did not show any significant differences among the HTs, although FlatPacks yielded a significantly higher penetration rate and more spermatozoa per penetrated oocyte (p<0.05) than did the straws. Changes in motility patterns, toward a more circular motility during cooling and PT, could be noticed where individual spermatozoa showed a capacitation-like motility pattern. The changes were more obvious with 10-h and 20-h HTs than with 3-h HT.

Impact of carpet construction on fluid penetration: The case of blood.

PubMed

Feng, Chengcheng; Michielsen, Stephen; Attinger, Daniel

2018-03-01

Bloodstains and bloodstain patterns are often observed at crime scenes and their analysis through bloodstain pattern analysis (BPA) can assist in reconstructing crime scenes. However, most published work related to BPA only deals with hard, non-porous surfaces and none of the studies have carefully characterized carpets. Soft and porous carpets are often encountered at crime scenes since they are common in American homes accounting for 51% of total U.S. flooring market; this has motivated the research described herein. To assess fluid penetration into tufted carpers, a new method for determining porosity and pore size distribution in tufted carpets has been developed for bloodstains on carpet. In this study, three kinds of nylon carpet were used: a low, a medium and a high face-weight carpet. Each carpet had an antistain treatment, which was removed from half of each carpet by steam-cleaning with a pH 12 NaOH solution. This resulted in six carpet samples. Yarn twist, carpet weight, pile height, water contact angles on carpets, water contact angles on individual fibers, and fiber cross-sectional shapes were characterized. Porosity and pore size distribution were analyzed using confocal laser scanning microscopy (CLSM). Porcine blood was used as a human blood substitute at three liquid volumes (30μL, 10μL, and 2μL). Analysis showed that porous carpet construction and antistain finishing both affected penetration. The depth of blood penetration decreased with the increase of carpet face-weight but increased with increased drop height. The removal of antistain treatment increased blood penetration into the carpets and changed the pore size distribution. Effects of antistain treatment, porosity and pore size distribution of tufted carpet, and blood wicking behaviors on carpets were found to strongly affect blood penetration into the carpets. Copyright © 2018 Elsevier B.V. All rights reserved.

Glide dislocation nucleation from dislocation nodes at semi-coherent {111} Cu–Ni interfaces

DOE PAGES

Shao, Shuai; Wang, Jian; Beyerlein, Irene J.; ...

2015-07-23

Using atomistic simulations and dislocation theory on a model system of semi-coherent {1 1 1} interfaces, we show that misfit dislocation nodes adopt multiple atomic arrangements corresponding to the creation and redistribution of excess volume at the nodes. We identified four distinctive node structures: volume-smeared nodes with (i) spiral or (ii) straight dislocation patterns, and volume-condensed nodes with (iii) triangular or (iv) hexagonal dislocation patterns. Volume-smeared nodes contain interfacial dislocations lying in the Cu–Ni interface but volume-condensed nodes contain two sets of interfacial dislocations in the two adjacent interfaces and jogs across the atomic layer between the two adjacent interfaces.more » Finally, under biaxial tension/compression applied parallel to the interface, we show that the nucleation of lattice dislocations is preferred at the nodes and is correlated with the reduction of excess volume at the nodes.« less

Evidence of benzenoid domains in nanographenes.

PubMed

Baldoni, Matteo; Mercuri, Francesco

2015-01-21

Calculations based on density functional theory demonstrate the occurrence of local deformations of the perfect honeycomb lattice in nanographenes to form arrangements, with triangular symmetry, composed of six-membered ring patterns. The formation of these locally regular superstructures, which can be considered as benzenoid-like domains on the 2D graphene lattice, is ascribed to the gain in resonance energy deriving from aromaticity. The relationship between the atomic morphology of nanographenes and details of the relaxed structure is rationalized in terms of Clar's theory of the aromatic sextet and by extending concepts borrowed from valence bond theory to 2D carbon nanostructures. Namely, two regular arrangements can be evidenced, defined as Clar (fully benzenoid) and Kekulé domains, which correspond to two different regular bond patterns in sets of adjacent six-membered rings. Our findings are compatible with recent experiments and have potentially relevant consequences in the development of novel electronic devices based on graphene materials.

High-order rogue wave solutions of the classical massive Thirring model equations

NASA Astrophysics Data System (ADS)

Guo, Lijuan; Wang, Lihong; Cheng, Yi; He, Jingsong

2017-11-01

The nth-order solutions of the classical massive Thirring model (MTM) equations are derived by using the n-fold Darboux transformation. These solutions are expressed by the ratios of the two determinants consisted of 2n eigenfunctions under the reduction conditions. Using this method, rogue waves are constructed explicitly up to the third-order. Three patterns, i.e., fundamental, triangular and circular patterns, of the rogue waves are discussed. The parameter μ in the MTM model plays the role of the mass in the relativistic field theory while in optics it is related to the medium periodic constant, which also results in a significant rotation and a remarkable lengthening of the first-order rogue wave. These results provide new opportunities to observe rouge waves by using a combination of electromagnetically induced transparency and the Bragg scattering four-wave mixing because of large amplitudes.

Seismic activity in the Sunnyside mining district, Utah, during 1967

USGS Publications Warehouse

Barnes, Barton K.; Dunrud, C. Richard; Hernandez, Jerome

1969-01-01

A seismic monitoring network near Sunnyside, Utah, consisting of a triangular array of seismometer stations that encompasses most of the mine workings in the district, recorded over 50,000 local earth tremors during 1967. About 540 of the tremors were of sufficient magnitude to be accurately located. Most of these were located within 2-3 miles of mine workings and were also near known or suspected faults. The district-wide seismic activity generally consisted of two different patterns--a periodic increase in the daily number of tremors at weekly intervals, and also a less regular and longer term increase and decrease of seismic activity that occurred over a period of weeks or even months. The shorter and more regular pattern can be correlated with the mine work week and seems to result from mining. The longer term activity, however, does not correlate with known mining causes sad therefore seems to be .caused by natural stresses.

A Novel Four-Node Quadrilateral Smoothing Element for Stress Enhancement and Error Estimation

NASA Technical Reports Server (NTRS)

Tessler, A.; Riggs, H. R.; Dambach, M.

1998-01-01

A four-node, quadrilateral smoothing element is developed based upon a penalized-discrete-least-squares variational formulation. The smoothing methodology recovers C1-continuous stresses, thus enabling effective a posteriori error estimation and automatic adaptive mesh refinement. The element formulation is originated with a five-node macro-element configuration consisting of four triangular anisoparametric smoothing elements in a cross-diagonal pattern. This element pattern enables a convenient closed-form solution for the degrees of freedom of the interior node, resulting from enforcing explicitly a set of natural edge-wise penalty constraints. The degree-of-freedom reduction scheme leads to a very efficient formulation of a four-node quadrilateral smoothing element without any compromise in robustness and accuracy of the smoothing analysis. The application examples include stress recovery and error estimation in adaptive mesh refinement solutions for an elasticity problem and an aerospace structural component.

Study of a vibrating plate: comparison between experimental (ESPI) and analytical results

NASA Astrophysics Data System (ADS)

Romero, G.; Alvarez, L.; Alanís, E.; Nallim, L.; Grossi, R.

2003-07-01

Real-time electronic speckle pattern interferometry (ESPI) was used for tuning and visualization of natural frequencies of a trapezoidal plate. The plate was excited to resonant vibration by a sinusoidal acoustical source, which provided a continuous range of audio frequencies. Fringe patterns produced during the time-average recording of the vibrating plate—corresponding to several resonant frequencies—were registered. From these interferograms, calculations of vibrational amplitudes by means of zero-order Bessel functions were performed in some particular cases. The system was also studied analytically. The analytical approach developed is based on the Rayleigh-Ritz method and on the use of non-orthogonal right triangular co-ordinates. The deflection of the plate is approximated by a set of beam characteristic orthogonal polynomials generated by using the Gram-Schmidt procedure. A high degree of correlation between computational analysis and experimental results was observed.

Effects of Shannon entropy and electric field on polaron in RbCl triangular quantum dot

NASA Astrophysics Data System (ADS)

M, Tiotsop; A, J. Fotue; S, C. Kenfack; N, Issofa; H, Fotsin; L, C. Fai

2016-04-01

In this paper, the time evolution of the quantum mechanical state of a polaron is examined using the Pekar type variational method on the condition of the electric-LO-phonon strong-coupling and polar angle in RbCl triangular quantum dot. We obtain the eigenenergies, and the eigenfunctions of the ground state, and the first excited state respectively. This system in a quantum dot can be treated as a two-level quantum system qubit and the numerical calculations are performed. The effects of Shannon entropy and electric field on the polaron in the RbCl triangular quantum dot are also studied.

Nonlinear vibrations of thin arbitrarily laminated composite plates subjected to harmonic excitations using DKT elements

NASA Astrophysics Data System (ADS)

Chiang, C. K.; Xue, David Y.; Mei, Chuh

1993-04-01

A finite element formulation is presented for determining the large-amplitude free and steady-state forced vibration response of arbitrarily laminated anisotropic composite thin plates using the Discrete Kirchhoff Theory (DKT) triangular elements. The nonlinear stiffness and harmonic force matrices of an arbitrarily laminated composite triangular plate element are developed for nonlinear free and forced vibration analyses. The linearized updated-mode method with nonlinear time function approximation is employed for the solution of the system nonlinear eigenvalue equations. The amplitude-frequency relations for convergence with gridwork refinement, triangular plates, different boundary conditions, lamination angles, number of plies, and uniform versus concentrated loads are presented.

Nonlinear vibrations of thin arbitrarily laminated composite plates subjected to harmonic excitations using DKT elements

NASA Technical Reports Server (NTRS)

Chiang, C. K.; Xue, David Y.; Mei, Chuh

1993-01-01

A finite element formulation is presented for determining the large-amplitude free and steady-state forced vibration response of arbitrarily laminated anisotropic composite thin plates using the Discrete Kirchhoff Theory (DKT) triangular elements. The nonlinear stiffness and harmonic force matrices of an arbitrarily laminated composite triangular plate element are developed for nonlinear free and forced vibration analyses. The linearized updated-mode method with nonlinear time function approximation is employed for the solution of the system nonlinear eigenvalue equations. The amplitude-frequency relations for convergence with gridwork refinement, triangular plates, different boundary conditions, lamination angles, number of plies, and uniform versus concentrated loads are presented.

Magnetoelectric control of spin-chiral ferroelectric domains in a triangular lattice antiferromagnet

NASA Astrophysics Data System (ADS)

Kimura, Kenta; Nakamura, Hiroyuki; Ohgushi, Kenya; Kimura, Tsuyoshi

2008-10-01

We have grown single crystals of a triangular lattice antiferromagnet (TLA), CuCrO2 , and investigated the correlation between magnetic and dielectric properties. Two magnetic phase transitions are observed at TN2≈24.2K and TN1≈23.6K . It was found that ferroelectric polarization along the triangular lattice plane develops at TN1 , suggesting that the system undergoes a transition into an out-of-plane 120° spin-chiral phase at TN1 . The TLA provides an opportunity for unique magnetoelectric control of spin-chiral ferroelectric domain structures by means of electric and/or magnetic fields.

Yu-Shiba-Rusinov states of impurities in a triangular lattice of NbSe2 with spin-orbit coupling

NASA Astrophysics Data System (ADS)

Ptok, Andrzej; Głodzik, Szczepan; Domański, Tadeusz

2017-11-01

We study the topography of the spin-polarized bound states of magnetic impurities embedded in a triangular lattice of a superconducting host. Such states have been observed experimentally in 2 H -NbSe2 crystal [G. C. Ménard et al., Nat. Phys. 11, 1013 (2015), 10.1038/nphys3508], and they revealed oscillating particle-hole asymmetry extending to tens of nanometers. Using the Bogoliubov-de Gennes approach, we explore the Yu-Shiba-Rusinov states in the presence of spin-orbit interaction. We also study the bound states of double impurities for several relative positions in a triangular lattice.

Lightning swept-stroke attachment patterns and flight conditions for storm hazards 1981

NASA Technical Reports Server (NTRS)

Fisher, B. D.

1984-01-01

As part of the NASA Langley Research Center Storm Hazards Program, 111 thunderstorm penetrations were made in 1981 with an F-106B airplane in order to record direct-strike lightning data and the associated flight conditions. Ground-based weather radar measurements in conjunction with these penetrations were made by NOAA National Severe Storms Laboratory in Oklahoma and by NASA Wallops Flight Facility in Virginia. In 1981, the airplane received 10 direct lightning strikes; in addition, lightning transient data were recorded from 22 nearby flashes. Following each flight, the airplane was thoroughly inspected for evidence of lightning attachment, and the individual lightning attachment points were plotted on isometric projections of the airplane to identify swept-flash patterns. This report shows the strike attachment patterns that were found, and tabulates the flight conditions at the time of each lightning event. Finally, this paper contains a table in which the data in this report are cross-referenced with the previously published electromagnetic waveform data recorded onboard the airplane.

Probing the anisotropic vortex lattice in the Fe-based superconductor KFe2As2 using small angle neutron scattering

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

Debeer-Schmitt, Lisa M; Dewhurst, Charles; Kikuchi, Hiroko

Using small angle neutron scattering, the anisotropy of the magnetic vortex lattice (VL), in the heavily hole-doped pnictide superconductor, KFe2As2, was studied. Well-ordered VL scattering patterns were measured with elds applied in directions between B k c and the basal plane, rotating either towards [100] or [110]. Slightly distorted hexagonal patterns were observed when B k c. However, the scattering pattern distorted strongly as the eld was rotated away from the c- axis. At low eld, the arrangement of vortices is strongly aected by the anisotropy of penetration depth in the plane perpendicular to the eld. By tting the distortionmore » with the anisotropic London model, we obtained an estimate of 3:4 for the anisotropy factor, , between the in-plane and c-axis penetration depths at the lowest temperature studied. The results further reveal VL phase transitions as a function of eld direction. We discuss these transitions using the "Hairy Ball" theorem.« less

Cause and Cure - Deterioration in Accuracy of CFD Simulations With Use of High-Aspect-Ratio Triangular Tetrahedral Grids

NASA Technical Reports Server (NTRS)

Chang, Sin-Chung; Chang, Chau-Lyan; Venkatachari, Balaji Shankar

2017-01-01

Traditionally high-aspect ratio triangular/tetrahedral meshes are avoided by CFD re-searchers in the vicinity of a solid wall, as it is known to reduce the accuracy of gradient computations in those regions and also cause numerical instability. Although for certain complex geometries, the use of high-aspect ratio triangular/tetrahedral elements in the vicinity of a solid wall can be replaced by quadrilateral/prismatic elements, ability to use triangular/tetrahedral elements in such regions without any degradation in accuracy can be beneficial from a mesh generation point of view. The benefits also carry over to numerical frameworks such as the space-time conservation element and solution element (CESE), where triangular/tetrahedral elements are the mandatory building blocks. With the requirement of the CESE method in mind, a rigorous mathematical framework that clearly identities the reason behind the difficulties in use of such high-aspect ratio triangular/tetrahedral elements is presented here. As will be shown, it turns out that the degree of accuracy deterioration of gradient computation involving a triangular element is hinged on the value of its shape factor Gamma def = sq sin Alpha1 + sq sin Alpha2 + sq sin Alpha3, where Alpha1; Alpha2 and Alpha3 are the internal angles of the element. In fact, it is shown that the degree of accuracy deterioration increases monotonically as the value of Gamma decreases monotonically from its maximal value 9/4 (attained by an equilateral triangle only) to a value much less than 1 (associated with a highly obtuse triangle). By taking advantage of the fact that a high-aspect ratio triangle is not necessarily highly obtuse, and in fact it can have a shape factor whose value is close to the maximal value 9/4, a potential solution to avoid accuracy deterioration of gradient computation associated with a high-aspect ratio triangular grid is given. Also a brief discussion on the extension of the current mathematical framework to the tetrahedral-grid case along with some of the practical results of this extension is also provided. Furthermore, through the use of numerical simulations of practical viscous problems involving high-Reynolds number flows, the effectiveness of the gradient evaluation procedures within the CESE framework (that have their basis on the analysis presented here) to produce accurate and stable results on such high-aspect ratio meshes is also showcased.

Tool calibration system for micromachining system

DOEpatents

Miller, Donald M.

1979-03-06

A tool calibration system including a tool calibration fixture and a tool height and offset calibration insert for calibrating the position of a tool bit in a micromachining tool system. The tool calibration fixture comprises a yokelike structure having a triangular head, a cavity in the triangular head, and a port which communicates a side of the triangular head with the cavity. Yoke arms integral with the triangular head extend along each side of a tool bar and a tool head of the micromachining tool system. The yoke arms are secured to the tool bar to place the cavity around a tool bit which may be mounted to the end of the tool head. Three linear variable differential transformer's (LVDT) are adjustably mounted in the triangular head along an X axis, a Y axis, and a Z axis. The calibration insert comprises a main base which can be mounted in the tool head of the micromachining tool system in place of a tool holder and a reference projection extending from a front surface of the main base. Reference surfaces of the calibration insert and a reference surface on a tool bar standard length are used to set the three LVDT's of the calibration fixture to the tool reference position. These positions are transferred permanently to a mastering station. The tool calibration fixture is then used to transfer the tool reference position of the mastering station to the tool bit.

Effective elastic moduli of triangular lattice material with defects

NASA Astrophysics Data System (ADS)

Liu, Xiaoyu; Liang, Naigang

2012-10-01

This paper presents an attempt to extend homogenization analysis for the effective elastic moduli of triangular lattice materials with microstructural defects. The proposed homogenization method adopts a process based on homogeneous strain boundary conditions, the micro-scale constitutive law and the micro-to-macro static operator to establish the relationship between the macroscopic properties of a given lattice material to its micro-discrete behaviors and structures. Further, the idea behind Eshelby's equivalent eigenstrain principle is introduced to replace a defect distribution by an imagining displacement field (eigendisplacement) with the equivalent mechanical effect, and the triangular lattice Green's function technique is developed to solve the eigendisplacement field. The proposed method therefore allows handling of different types of microstructural defects as well as its arbitrary spatial distribution within a general and compact framework. Analytical closed-form estimations are derived, in the case of the dilute limit, for all the effective elastic moduli of stretch-dominated triangular lattices containing fractured cell walls and missing cells, respectively. Comparison with numerical results, the Hashin-Shtrikman upper bounds and uniform strain upper bounds are also presented to illustrate the predictive capability of the proposed method for lattice materials. Based on this work, we propose that not only the effective Young's and shear moduli but also the effective Poisson's ratio of triangular lattice materials depend on the number density of fractured cell walls and their spatial arrangements.

Reconfirmation of the anatomy of the left triangular ligament and the appendix fibrosa hepatis in human livers, and its implication in abdominal surgery.

PubMed

Kogure, Kimitaka; Kojima, Itaru; Kuwano, Hiroyuki; Matsuzaki, Toshiyuki; Yorifuji, Hiroshi; Takata, Kuniaki; Makuuchi, Masatoshi

2014-12-01

The aim of the present study was to clarify the anatomy between the left triangular ligament (LTL) and the appendix fibrosa hepatis (AFH) in order not to sever the AFH when dissecting the LTL. Totals of 43 and 27 cadaveric livers were examined macroscopically and histologically, respectively. The LTL attached itself to the diaphragmatic surface of the AFH through almost all lengths of the AFH. This might be the reason why AFH is so often dissected together with the LTL. There were two types of relation between the LTL and the AFH; in one type, the starting point of the LTL existed on the left liver and in the other type, it was on the AFH. Twenty-five of 27 AFH included remnants of the bile duct and 12 of 25 AFH had comparatively large bile ducts, which was unexceptionally accompanied by the well-developed peribiliary vascular plexus. AFH showed a variety of shapes, such as rectangular (6/43), long triangular (4/43), short triangular (7/43), triangular plus cordlike (11/43), cordlike (12/43) and bifurcated (3/43) types. As AFH sometimes includes relatively large bile ducts, it is recommended for surgeons to sever the AFH not just simply by electrocautery but by ligating its stump securely. © 2014 Japanese Society of Hepato-Biliary-Pancreatic Surgery.

A tumor-penetrating peptide enhances circulation-independent targeting of peritoneal carcinomatosis

PubMed Central

Sugahara, Kazuki N.; Scodeller, Pablo; Braun, Gary B.; de Mendoza, Tatiana Hurtado; Yamazaki, Chisato M.; Kluger, Michael D.; Kitayama, Joji; Alvarez, Edwin; Howell, Stephen B.; Teesalu, Tambet; Ruoslahti, Erkki; Lowy, Andrew M.

2015-01-01

Peritoneal carcinomatosis is a major source of morbidity and mortality in patients with advanced abdominal neoplasms. Intraperitoneal chemotherapy (IPC) is an area of intense interest given its efficacy in ovarian cancer. However, IPC suffers from poor drug penetration into peritoneal tumors. As such, extensive cytoreductive surgery is required prior to IPC. Here, we explore the utility of iRGD, a tumor-penetrating peptide, for improved tumor-specific penetration of intraperitoneal compounds and enhanced IPC in mice. Intraperitoneally administered iRGD significantly enhanced penetration of an attached fluorescein into disseminated peritoneal tumor nodules. The penetration was tumor-specific, circulation-independent, and mediated by the neuropilin-binding RXXK tissue-penetration peptide motif of iRGD. Q-iRGD, which fluoresces upon cleavage, including the one that leads to RXXK activation, specifically labeled peritoneal metastases displaying different growth patterns in mice. Importantly, iRGD enhanced intratumoral entry of intraperitoneally co-injected dextran to approximately 300% and doxorubicin to 250%. Intraperitoneal iRGD/doxorubicin combination therapy inhibited the growth of bulky peritoneal tumors and reduced systemic drug toxicity. iRGD delivered attached fluorescein and co-applied nanoparticles deep into fresh human peritoneal metastasis explants. These results indicate that intraperitoneal iRGD co-administration serves as a simple and effective strategy to facilitate tumor detection and improve the therapeutic index of IPC for peritoneal carcinomatosis. PMID:26071630

Anisotropic adhesion properties of triangular-tip-shaped micropillars.

PubMed

Kwak, Moon Kyu; Jeong, Hoon Eui; Bae, Won Gyu; Jung, Ho-Sup; Suh, Kahp Y

2011-08-22

Directional dry adhesive microstructures consisting of high-density triangular-tip-shaped micropillars are described. The wide-tip structures allow for unique directional shear adhesion properties with respect to the peeling direction, along with relatively high normal adhesion. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Triangular Plots and Spreadsheet Software.

ERIC Educational Resources Information Center

Holm, Paul Eric

1988-01-01

Describes how the limitations of the built-in graphics capabilities of spreadsheet software can be overcome by making full use of the flexibility of the grahics options. Uses triangular plots with labeled field boundaries produced using Lotus 1-2-3 to demonstrate these techniques and their use in teaching geology. (CW)

All Square Chiliagonal Numbers

ERIC Educational Resources Information Center

A?iru, Muniru A.

2016-01-01

A square chiliagonal number is a number which is simultaneously a chiliagonal number and a perfect square (just as the well-known square triangular number is both triangular and square). In this work, we determine which of the chiliagonal numbers are perfect squares and provide the indices of the corresponding chiliagonal numbers and square…

Regular Deployment of Wireless Sensors to Achieve Connectivity and Information Coverage

PubMed Central

Cheng, Wei; Li, Yong; Jiang, Yi; Yin, Xipeng

2016-01-01

Coverage and connectivity are two of the most critical research subjects in WSNs, while regular deterministic deployment is an important deployment strategy and results in some pattern-based lattice WSNs. Some studies of optimal regular deployment for generic values of rc/rs were shown recently. However, most of these deployments are subject to a disk sensing model, and cannot take advantage of data fusion. Meanwhile some other studies adapt detection techniques and data fusion to sensing coverage to enhance the deployment scheme. In this paper, we provide some results on optimal regular deployment patterns to achieve information coverage and connectivity as a variety of rc/rs, which are all based on data fusion by sensor collaboration, and propose a novel data fusion strategy for deployment patterns. At first the relation between variety of rc/rs and density of sensors needed to achieve information coverage and connectivity is derived in closed form for regular pattern-based lattice WSNs. Then a dual triangular pattern deployment based on our novel data fusion strategy is proposed, which can utilize collaborative data fusion more efficiently. The strip-based deployment is also extended to a new pattern to achieve information coverage and connectivity, and its characteristics are deduced in closed form. Some discussions and simulations are given to show the efficiency of all deployment patterns, including previous patterns and the proposed patterns, to help developers make more impactful WSN deployment decisions. PMID:27529246

A direct temporal domain approach for ultrafast optical signal processing and its implementation using planar lightwave circuits

NASA Astrophysics Data System (ADS)

Xia, Bing

Ultrafast optical signal processing, which shares the same fundamental principles of electrical signal processing, can realize numerous important functionalities required in both academic research and industry. Due to the extremely fast processing speed, all-optical signal processing and pulse shaping have been widely used in ultrafast telecommunication networks, photonically-assisted RFlmicro-meter waveform generation, microscopy, biophotonics, and studies on transient and nonlinear properties of atoms and molecules. In this thesis, we investigate two types of optical spectrally-periodic (SP) filters that can be fabricated on planar lightwave circuits (PLC) to perform pulse repetition rate multiplication (PRRM) and arbitrary optical waveform generation (AOWG). First, we present a direct temporal domain approach for PRRM using SP filters. We show that the repetition rate of an input pulse train can be multiplied by a factor N using an optical filter with a free spectral range that does not need to be constrained to an integer multiple of N. Furthermore, the amplitude of each individual output pulse can be manipulated separately to form an arbitrary envelope at the output by optimizing the impulse response of the filter. Next, we use lattice-form Mach-Zehnder interferometers (LF-MZI) to implement the temporal domain approach for PRRM. The simulation results show that PRRM with uniform profiles, binary-code profiles and triangular profiles can be achieved. Three silica based LF-MZIs are designed and fabricated, which incorporate multi-mode interference (MMI) couplers and phase shifters. The experimental results show that 40 GHz pulse trains with a uniform envelope pattern, a binary code pattern "1011" and a binary code pattern "1101" are generated from a 10 GHz input pulse train. Finally, we investigate 2D ring resonator arrays (RRA) for ultraf ast optical signal processing. We design 2D RRAs to generate a pair of pulse trains with different binary-code patterns simultaneously from a single pulse train at a low repetition rate. We also design 2D RRAs for AOWG using the modified direct temporal domain approach. To demonstrate the approach, we provide numerical examples to illustrate the generation of two very different waveforms (square waveform and triangular waveform) from the same hyperbolic secant input pulse train. This powerful technique based on SP filters can be very useful for ultrafast optical signal processing and pulse shaping.

Predictions and retrodictions of the hierarchical representation of habitat in heterogeneous environments

USGS Publications Warehouse

Kolasa, Jurek; Allen, Craig R.; Sendzimir, Jan; Stow, Craig A.

2012-01-01

Interaction between habitat and species is central in ecology. Habitat structure may be conceived as being hierarchical, where larger, more diverse, portions or categories contain smaller, more homogeneous portions. When this conceptualization is combined with the observation that species have different abilities to relate to portions of the habitat that differ in their characteristics, a number of known patterns can be derived and new patterns hypothesized. We propose a quantitative form of this habitat–species relationship by considering species abundance to be a function of habitat specialization, habitat fragmentation, amount of habitat, and adult body mass. The model reproduces and explains patterns such as variation in rank–abundance curves, greater variation and extinction probabilities of habitat specialists, discontinuities in traits (abundance, ecological range, pattern of variation, body size) among species sharing a community or area, and triangular distribution of body sizes, among others. The model has affinities to Holling's textural discontinuity hypothesis and metacommunity theory but differs from both by offering a more general perspective. In support of the model, we illustrate its general potential to capture and explain several empirical observations that historically have been treated independently.

Few-cycle optical rogue waves: complex modified Korteweg-de Vries equation.

PubMed

He, Jingsong; Wang, Lihong; Li, Linjing; Porsezian, K; Erdélyi, R

2014-06-01

In this paper, we consider the complex modified Korteweg-de Vries (mKdV) equation as a model of few-cycle optical pulses. Using the Lax pair, we construct a generalized Darboux transformation and systematically generate the first-, second-, and third-order rogue wave solutions and analyze the nature of evolution of higher-order rogue waves in detail. Based on detailed numerical and analytical investigations, we classify the higher-order rogue waves with respect to their intrinsic structure, namely, fundamental pattern, triangular pattern, and ring pattern. We also present several new patterns of the rogue wave according to the standard and nonstandard decomposition. The results of this paper explain the generalization of higher-order rogue waves in terms of rational solutions. We apply the contour line method to obtain the analytical formulas of the length and width of the first-order rogue wave of the complex mKdV and the nonlinear Schrödinger equations. In nonlinear optics, the higher-order rogue wave solutions found here will be very useful to generate high-power few-cycle optical pulses which will be applicable in the area of ultrashort pulse technology.

Bioinspired Surface for Surgical Graspers Based on the Strong Wet Friction of Tree Frog Toe Pads.

PubMed

Chen, Huawei; Zhang, Liwen; Zhang, Deyuan; Zhang, Pengfei; Han, Zhiwu

2015-07-01

Soft tissue damage is often at risk during the use of a surgical grasper, because of the strong holding force required to prevent slipping of the soft tissue in wet surgical environments. Improvement of wet friction properties at the interface between the surgical grasper and soft tissue can greatly reduce the holding force required and, thus, the soft tissue damage. To design and fabricate a biomimetic microscale surface with strong wet friction, the wet attachment mechanism of tree frog toe pads was investigated by observing their epithelial cell structure and the directionally dependent friction on their toe pads. Using these observations as inspiration, novel surface micropatterns were proposed for the surface of surgical graspers. The wet friction of biomimetic surfaces with various types of polygon pillar patterns involving quadrangular pillars, triangular pillars, rhomboid pillars, and varied hexagonal pillars were tested. The hexagonal pillar pattern exhibited improved wet frictional performance over the modern surgical grasper jaw pattern, which has conventional macroscale teeth. Moreover, the deformation of soft tissue in the bioinspired surgical grasper with a hexagonal pillar pattern is decreased, compared with the conventional surgical grasper.

Efficient ICCG on a shared memory multiprocessor

NASA Technical Reports Server (NTRS)

Hammond, Steven W.; Schreiber, Robert

1989-01-01

Different approaches are discussed for exploiting parallelism in the ICCG (Incomplete Cholesky Conjugate Gradient) method for solving large sparse symmetric positive definite systems of equations on a shared memory parallel computer. Techniques for efficiently solving triangular systems and computing sparse matrix-vector products are explored. Three methods for scheduling the tasks in solving triangular systems are implemented on the Sequent Balance 21000. Sample problems that are representative of a large class of problems solved using iterative methods are used. We show that a static analysis to determine data dependences in the triangular solve can greatly improve its parallel efficiency. We also show that ignoring symmetry and storing the whole matrix can reduce solution time substantially.

Numerical-Diagonalization Study of Magnetization Process of Frustrated Spin-1/2 Heisenberg Antiferromagnets in Two Dimensions: —Triangular- and Kagome-Lattice Antiferromagnets—

NASA Astrophysics Data System (ADS)

Nakano, Hiroki; Sakai, Tôru

2018-06-01

The S = 1/2 triangular- and kagome-lattice Heisenberg antiferromagnets are investigated under a magnetic field using the numerical-diagonalization method. A procedure is proposed to extract data points with very small finite-size deviations using the numerical-diagonalization results for capturing the magnetization curve. For the triangular-lattice antiferromagnet, the plateau edges at one-third the height of the saturation and the saturation field are successfully estimated. This study additionally presents results of magnetization process for a 45-site cluster of the kagome-lattice antiferromagnet; the present analysis suggests that the plateau does not open at one-ninth the height of the saturation.

Continuous analogues of matrix factorizations

PubMed Central

Townsend, Alex; Trefethen, Lloyd N.

2015-01-01

Analogues of singular value decomposition (SVD), QR, LU and Cholesky factorizations are presented for problems in which the usual discrete matrix is replaced by a ‘quasimatrix’, continuous in one dimension, or a ‘cmatrix’, continuous in both dimensions. Two challenges arise: the generalization of the notions of triangular structure and row and column pivoting to continuous variables (required in all cases except the SVD, and far from obvious), and the convergence of the infinite series that define the cmatrix factorizations. Our generalizations of triangularity and pivoting are based on a new notion of a ‘triangular quasimatrix’. Concerning convergence of the series, we prove theorems asserting convergence provided the functions involved are sufficiently smooth. PMID:25568618

Treatment of displaced intra-articular calcaneal fractures with triangular tube-to-bar external fixation: long-term clinical follow-up and radiographic analysis.

PubMed

Roukis, Thomas S; Wünschel, Markus; Lutz, Hans-Peter; Kirschner, Peter; Zgonis, Thomas

2008-04-01

Sixty-six feet (62 patients) with displaced intra-articular calcaneal fractures underwent manual reduction and distraction with the use of a triangular tube-to-bar external fixation device and were retrospectively reviewed at a minimum of 1-year post-operative. Final radiographic follow-up revealed complete consolidation in all fractures, maintenance of reduction, and limited degenerative osteoarthrosis about the subtalar joint. Our results indicate that with proper application and attention to detail, restoration of calcaneal morphology using triangular tube-to-bar external fixation should be considered a viable alternative in the treatment of displaced intra-articular fractures of the calcaneus.

A study of the pattern, management and outcome of penetrating colon injuries in Sagamu.

PubMed

Tade, A O; Thanni, L O A; Ayoade, B A

2009-09-01

Colon injuries are increasingly being treated safely by primary repair in spite of the high risk of septic complications. This is a retrospective study of the pattern, management and outcome in patients treated for penetrating colon injuries at Olabisi Onabanjo University Teaching Hospital, Sagamu over a 7 year period (January 1995-December 2001). Records of thirty-two patients were studied. Gunshots (75 percent) and knife stabs (18.75 percent) accounted for ninety-four percent of penetrating colon injuries. Associated intra-abdominal injuries were present in 22 patients (68.8 percent). Eight (twenty-five percent) patients presented in shock. Moderate to major faecal contamination was present in 30 (93.8%) patients. Severe colon injury occurred in nine patients. The eighteen patients with right colon wounds were managed by primary repair. All the fourteen patients with left colon wounds had a diverting colostomy alongside repair or resection. Complications included wound infection (56.7 percent) and septicaemia (31.7 percent). Eleven patients died, giving an overall mortality rate of 34.4 percent. Mortality was significantly associated with shock on admission (p<0.02), degree of faecal contamination (p<0.05) and severity of colon injury (p<0.01). Colostomy did not affect mortality. (P<0.1). In this study primary repair was employed in 56% of patients with penetrating colon injuries. The routine use of diverting colostomy for all left colon injuries can no longer be justified in current surgical practice as colostomy did not affect mortality.

Adsorption of lysozyme to phospholipid and meibomian lipid monolayer films.

PubMed

Mudgil, Poonam; Torres, Margaux; Millar, Thomas J

2006-03-15

It is believed that a lipid layer forms the outer layer of the pre-ocular tear film and this layer helps maintain tear film stability by lowering its surface tension. Proteins of the aqueous layer of the tear film (beneath the lipid layer) may also contribute to reducing surface tension by adsorbing to, or penetrating the lipid layer. The purpose of this study was to compare the penetration of lysozyme, a tear protein, into films of meibomian lipids and phospholipids held at different surface pressures to determine if lysozyme were part of the surface layer of the tear film. Films of meibomian lipids or phospholipids were spread onto the surface of a buffered aqueous subphase. Films were compressed to particular pressures and lysozyme was injected into the subphase. Changes in surface pressure were monitored to determine adsorption or penetration of lysozyme into the surface film. Lysozyme penetrated a meibomian lipid film at all pressures tested (max=20 mN/m). It also penetrated phosphatidylglycerol, phosphatidylserine or phosphatidylethanolamine lipid films up to a pressure of 20 mN/m. It was not able to penetrate a phosphatidylcholine film at pressures >or=10 mN/m irrespective of the temperature being at 20 or 37 degrees C. However, it was able to penetrate it at very low pressures (<10 mN/m). Epifluorescence microscopy showed that the protein either adsorbs to or penetrates the lipid layer and the pattern of mixing depended upon the lipid at the surface. These results indicate that lysozyme is present at the surface of the tear film where it contributes to decreasing the surface tension by adsorbing and penetrating the meibomian lipids. Thus it helps to stabilize the tear film.

Modeling the Pathophysiology of Phonotraumatic Vocal Hyperfunction with a Triangular Glottal Model of the Vocal Folds

ERIC Educational Resources Information Center

Galindo, Gabriel E.; Peterson, Sean D.; Erath, Byron D.; Castro, Christian; Hillman, Robert E.; Zañartu, Matías

2017-01-01

Purpose: Our goal was to test prevailing assumptions about the underlying biomechanical and aeroacoustic mechanisms associated with phonotraumatic lesions of the vocal folds using a numerical lumped-element model of voice production. Method: A numerical model with a triangular glottis, posterior glottal opening, and arytenoid posturing is…

Eigenvalues of Rectangular Waveguide Using FEM With Hybrid Elements

NASA Technical Reports Server (NTRS)

Deshpande, Manohar D.; Hall, John M.

2002-01-01

A finite element analysis using hybrid triangular-rectangular elements is developed to estimate eigenvalues of a rectangular waveguide. Use of rectangular vector-edge finite elements in the vicinity of the PEC boundary and triangular elements in the interior region more accurately models the physical nature of the electromagnetic field, and consequently quicken the convergence.

Basic Employability Skills: A Triangular Design Approach

ERIC Educational Resources Information Center

Rosenberg, Stuart; Heimler, Ronald; Morote, Elsa-Sofia

2012-01-01

Purpose: This paper seeks to examine the basic employability skills needed for job performance, the reception of these skills in college, and the need for additional training in these skills after graduation. Design/methodology/approach: The research was based on a triangular design approach, in which the attitudes of three distinct groups--recent…

Pressure deformation of tires using differential stiffness for triangular solid-of-revolution elements

NASA Technical Reports Server (NTRS)

Chen, C. H. S.

1975-01-01

The derivation is presented of the differential stiffness for triangular solid of revolution elements. The derivation takes into account the element rigid body rotation only, the rotation being about the circumferential axis. Internal pressurization of a pneumatic tire is used to illustrate the application of this feature.

Perceptions of Love across the Lifespan: Differences in Passion, Intimacy, and Commitment

ERIC Educational Resources Information Center

Sumter, Sindy R.; Valkenburg, Patti M.; Peter, Jochen

2013-01-01

This study investigated perceptions of love across the lifespan using Sternberg's triangular theory of love, which distinguishes between passion, intimacy, and commitment. The study aimed to (a) investigate the psychometric properties of the short Triangular Love Scale (TLS-short) in adolescents and adults (see Appendix), and (b) track age and…

Breaking away from the Pack: Positioning the Marketing Discipline through a Triangular Analysis.

ERIC Educational Resources Information Center

Bonnici, Joseph L.; Reddy, Allan C.

1993-01-01

College and university marketing departments should use the technique of positioning to increase enrollments. The triangular approach to positioning uses close scrutiny of the student profile, the benefits marketing courses offer, and the competition the department faces within and outside the business school. The technique can also be used by…

76 FR 28890 - Treatment of Property Used To Acquire Parent Stock or Securities in Certain Triangular...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-19

... Treatment of Property Used To Acquire Parent Stock or Securities in Certain Triangular Reorganizations... 367 of the Internal Revenue Code (Code) relating to the treatment of property used to acquire parent... subsidiary (S) purchases, in connection with the reorganization, stock of its parent corporation (P) in...

49 CFR 238.435 - Interior fittings and surfaces.

Code of Federal Regulations, 2012 CFR

2012-10-01

... expected to strike the fitting, when the floor of the passenger car decelerates with a triangular crash... attachment in a passenger car shall be designed to withstand, with deflection but without total failure, the... triangular crash pulse having a peak of 8g and a duration of 250 milliseconds. (b) Each seat back in a...

49 CFR 238.435 - Interior fittings and surfaces.

Code of Federal Regulations, 2013 CFR

2013-10-01

... expected to strike the fitting, when the floor of the passenger car decelerates with a triangular crash... attachment in a passenger car shall be designed to withstand, with deflection but without total failure, the... triangular crash pulse having a peak of 8g and a duration of 250 milliseconds. (b) Each seat back in a...

49 CFR 238.435 - Interior fittings and surfaces.

Code of Federal Regulations, 2014 CFR

2014-10-01

... expected to strike the fitting, when the floor of the passenger car decelerates with a triangular crash... attachment in a passenger car shall be designed to withstand, with deflection but without total failure, the... triangular crash pulse having a peak of 8g and a duration of 250 milliseconds. (b) Each seat back in a...

49 CFR 238.435 - Interior fittings and surfaces.

Code of Federal Regulations, 2011 CFR

2011-10-01

... expected to strike the fitting, when the floor of the passenger car decelerates with a triangular crash... attachment in a passenger car shall be designed to withstand, with deflection but without total failure, the... triangular crash pulse having a peak of 8g and a duration of 250 milliseconds. (b) Each seat back in a...

A Triangular Approach to Integrate Research, Education and Practice in Higher Engineering Education

ERIC Educational Resources Information Center

Heikkinen, Eetu-Pekka; Jaako, Juha; Hiltunen, Jukka

2017-01-01

Separate approaches in engineering education, research and practice are not very useful when preparing students for working life; instead, integration of education, research and industrial practices is needed. A triangular approach (TA) as a method to accomplish this integration and as a method to provide students with integrated expertise is…

View of the demilune, a triangular piece of land that ...

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

View of the demilune, a triangular piece of land that protected the rear of gorge wall of the fort. After the civil war, large earthen mounds were built in the demilune area. These mounds overlay four powder magazines and passageways to several gun emplacements. - Fort Pulaski, Cockspur Island, Savannah, Chatham County, GA

Rogue wave spectra of the Kundu-Eckhaus equation.

PubMed

Bayındır, Cihan

2016-06-01

In this paper we analyze the rogue wave spectra of the Kundu-Eckhaus equation (KEE). We compare our findings with their nonlinear Schrödinger equation (NLSE) analogs and show that the spectra of the individual rogue waves significantly differ from their NLSE analogs. A remarkable difference is the one-sided development of the triangular spectrum before the rogue wave becomes evident in time. Also we show that increasing the skewness of the rogue wave results in increased asymmetry in the triangular Fourier spectra. Additionally, the triangular spectra of the rogue waves of the KEE begin to develop at earlier stages of their development compared to their NLSE analogs, especially for larger skew angles. This feature may be used to enhance the early warning times of the rogue waves. However, we show that in a chaotic wave field with many spectral components the triangular spectra remain as the main attribute as a universal feature of the typical wave fields produced through modulation instability and characteristic features of the KEE's analytical rogue wave spectra may be suppressed in a realistic chaotic wave field.

Global performance enhancements via pedestal optimisation on ASDEX Upgrade

NASA Astrophysics Data System (ADS)

Dunne, M. G.; Frassinetti, L.; Beurskens, M. N. A.; Cavedon, M.; Fietz, S.; Fischer, R.; Giannone, L.; Huijsmans, G. T. A.; Kurzan, B.; Laggner, F.; McCarthy, P. J.; McDermott, R. M.; Tardini, G.; Viezzer, E.; Willensdorfer, M.; Wolfrum, E.; The EUROfusion MST1 Team; The ASDEX Upgrade Team

2017-02-01

Results of experimental scans of heating power, plasma shape, and nitrogen content are presented, with a focus on global performance and pedestal alteration. In detailed scans at low triangularity, it is shown that the increase in stored energy due to nitrogen seeding stems from the pedestal. It is also shown that the confinement increase is driven through the temperature pedestal at the three heating power levels studied. In a triangularity scan, an orthogonal effect of shaping and seeding is observed, where increased plasma triangularity increases the pedestal density, while impurity seeding (carbon and nitrogen) increases the pedestal temperature in addition to this effect. Modelling of these effects was also undertaken, with interpretive and predictive models being employed. The interpretive analysis shows a general agreement of the experimental pedestals in separate power, shaping, and seeding scans with peeling-ballooning theory. Predictive analysis was used to isolate the individual effects, showing that the trends of additional heating power and increased triangularity can be recoverd. However, a simple change of the effective charge in the plasma cannot explain the observed levels of confinement improvement in the present models.

Low frequency AC waveform generator

DOEpatents

Bilharz, Oscar W.

1986-01-01

Low frequency sine, cosine, triangle and square waves are synthesized in circuitry which allows variation in the waveform amplitude and frequency while exhibiting good stability and without requiring significant stabilization time. A triangle waveform is formed by a ramped integration process controlled by a saturation amplifier circuit which produces the necessary hysteresis for the triangle waveform. The output of the saturation circuit is tapped to produce the square waveform. The sine waveform is synthesized by taking the absolute value of the triangular waveform, raising this absolute value to a predetermined power, multiplying the raised absolute value of the triangle wave with the triangle wave itself and properly scaling the resultant waveform and subtracting it from the triangular waveform itself. The cosine is synthesized by squaring the triangular waveform, raising the triangular waveform to a predetermined power and adding the squared waveform raised to the predetermined power with a DC reference and subtracting the squared waveform therefrom, with all waveforms properly scaled. The resultant waveform is then multiplied with a square wave in order to correct the polarity and produce the resultant cosine waveform.

First principles study of edge carboxylated graphene quantum dots

NASA Astrophysics Data System (ADS)

Abdelsalam, Hazem; Elhaes, Hanan; Ibrahim, Medhat A.

2018-05-01

The structure stability and electronic properties of edge carboxylated hexagonal and triangular graphene quantum dots are investigated using density functional theory. The calculated binding energies show that the hexagonal clusters with armchair edges have the highest stability among all the quantum dots. The binding energy of carboxylated graphene quantum dots increases by increasing the number of carboxyl groups. Our study shows that the total dipole moment significantly increases by adding COOH with the highest value observed in triangular clusters. The edge states in triangular graphene quantum dots with zigzag edges produce completely different energy spectrum from other dots: (a) the energy gap in triangular zigzag is very small as compared to other clusters and (b) the highest occupied molecular orbital is localized at the edges which is in contrast to other clusters where it is distributed over the cluster surface. The enhanced reactivity and the controllable energy gap by shape and edge termination make graphene quantum dots ideal for various nanodevice applications such as sensors. The infrared spectra are presented to confirm the stability of the quantum dots.

Constraining ejecta particle size distributions with light scattering

NASA Astrophysics Data System (ADS)

Schauer, Martin; Buttler, William; Frayer, Daniel; Grover, Michael; Lalone, Brandon; Monfared, Shabnam; Sorenson, Daniel; Stevens, Gerald; Turley, William

2017-06-01

The angular distribution of the intensity of light scattered from a particle is strongly dependent on the particle size and can be calculated using the Mie solution to Maxwell's equations. For a collection of particles with a range of sizes, the angular intensity distribution will be the sum of the contributions from each particle size weighted by the number of particles in that size bin. The set of equations describing this pattern is not uniquely invertible, i.e. a number of different distributions can lead to the same scattering pattern, but with reasonable assumptions about the distribution it is possible to constrain the problem and extract estimates of the particle sizes from a measured scattering pattern. We report here on experiments using particles ejected by shockwaves incident on strips of triangular perturbations machined into the surface of tin targets. These measurements indicate a bimodal distribution of ejected particle sizes with relatively large particles (median radius 2-4 μm) evolved from the edges of the perturbation strip and smaller particles (median radius 200-600 nm) from the perturbations. We will briefly discuss the implications of these results and outline future plans.

Spin liquid state in the disordered triangular lattice Sc 2Ga 2CuO 7 revealed by NMR

DOE PAGES

Khuntia, P.; Kumar, R.; Mahajan, A. V.; ...

2016-04-18

We present microscopic magnetic properties of a two-dimensional triangular lattice Sc 2Ga 2CuO 7, consisting of single and double triangular Cu planes. An antiferromagnetic (AFM) exchange interaction J/k B ≈ 35 K between Cu 2+ (S = 1/2) spins in the triangular biplane is obtained from the analysis of intrinsic magnetic susceptibility data. The intrinsic magnetic susceptibility, extracted from 71Ga NMR shift data, displays the presence of AFM short range spin correlations and remains finite down to 50 mK, suggesting a nonsinglet ground state. The nuclear spin-lattice relaxation rate (1/T 1) reveals a slowing down of Cu 2+ spin fluctuationsmore » with decreasing T down to 100 mK. Magnetic specific heat (C m) and 1/T 1 exhibit power law behavior at low temperatures, implying the gapless nature of the spin excitation spectrum. The absence of long range magnetic ordering down to ~J/700, nonzero spin susceptibility at low T, and the power law behavior of C m and 1/T 1 suggest a gapless quantum spin liquid (QSL) state. Our results demonstrate that persistent spin dynamics induced by frustration maintain a quantum-disordered state at T → 0 in this triangular lattice antiferromagnet. Furthermore, this suggests that the low energy modes are dominated by spinon excitations in the QSL state due to randomness engendered by disorder and frustration.« less

Echocardiographic assessment of mitral valve morphology and performance after triangular resection of the prolapsing posterior leaflet for degenerative myxomatous disease.

PubMed

Chiappini, Bruno; Gregorini, Renato; De Remigis, Franco; Petrella, Licia; Villani, Carmine; Di Pietrantonio, Fabrizio; Pavicevic, Srdan; Mazzola, Alessandro

2009-08-01

The gold standard for the surgical treatment of prolapse of the posterior leaflet of the mitral valve (MV) for degenerative myxomatous disease has been represented by the quadrangular resection of the leaflet, according to the Carpentier technique. Since 2006 we performed a triangular resection of the prolapsing leaflet in 20 patients with myxomatous mitral regurgitation (MR). Seventeen patients (85%) underwent the triangular resection of P2; one patient (5%) had a triple scallops triangular resection (P1, P2, P3) and two (10%) a double scallops (P2, P3) resection. In this study, we report the immediate and mid-term clinical and echocardiographic results of a cohort of 20 patients, who underwent this technique. Thirty-day mortality was 0. Acute renal failure occurred in three patients (15%) and they resolved with conservative management. One patient (5%) required re-exploration for bleeding. At the mean follow-up of 13.1+/-4.2 months survival was 95%; one patient died of lymphoma during the follow-up time. All the cases were in New York Heart Association (NYHA) class I. Nineteen survivors underwent transthoracic echocardiography (TTE) (5), or transesophageal echocardiography (TEE) (13), performed by two skilled cardiologists. All patients showed no or trivial MV regurgitation. We believe that triangular resection of posterior MV leaflet (PMVL) provides excellent mid-term results providing the surgeon with a reliable and reproducible surgical option for myxomatous degenerative MV regurgitation.

Elliptic nozzle aspect ratio effect on controlled jet propagation

NASA Astrophysics Data System (ADS)

Aravindh Kumar, S. M.; Rathakrishnan, Ethirajan

2017-04-01

The present study deals with the control of a Mach 2 elliptic jet from a convergent-divergent elliptic nozzle of aspect ratio 4 using tabs at the nozzle exit. The experiments were carried out for rectangular and triangular tabs of the same blockage, placed along the major and minor axes of the nozzle exit, at different levels of nozzle expansion. The triangular tabs along the minor axis promoted superior mixing compared to the other controlled jets and caused substantial core length reduction at all the nozzle pressure ratios studied. The rectangular tabs along the minor axis caused core length reduction at all pressure ratios, but the values were minimal compared to that of triangular tabs along the minor axis. For all the test conditions, the mixing promotion caused by tabs along the major axis was inferior to that of tabs along the minor axis. The waves present in the core of controlled jets were visualized using a shadowgraph. Comparison of the present results with the results of a controlled Mach 2 elliptic jet of aspect ratio 2 (Aravindh Kumar and Sathakrishnan 2016 J. Propulsion Power 32 121-33, Aravindh Kumar and Rathakrishnan 2016 J. Aerospace Eng. at press (doi:10.1177/0954410016652921)) show that for all levels of expansion, the mixing effectiveness of triangular tabs along the minor axis of an aspect ratio 4 nozzle is better than rectangular or triangular tabs along the minor axis of an aspect ratio 2 nozzle.

Freezing tolerance of sea urchin embryonic cells: Differentiation commitment and cytoskeletal disturbances in culture.

PubMed

Odintsova, Nelly A; Ageenko, Natalya V; Kipryushina, Yulia O; Maiorova, Mariia A; Boroda, Andrey V

2015-08-01

This study focuses on the freezing tolerance of sea urchin embryonic cells. To significantly reduce the loss of physiological activity of these cells that occurs after cryopreservation and to study the effects of ultra-low temperatures on sea urchin embryonic cells, we tested the ability of the cells to differentiate into spiculogenic or pigment directions in culture, including an evaluation of the expression of some genes involved in pigment differentiation. A morphological analysis of cytoskeletal disturbances after freezing in a combination of penetrating (dimethyl sulfoxide and ethylene glycol) and non-penetrating (trehalose and polyvinylpyrrolidone) cryoprotectants revealed that the distribution pattern of filamentous actin and tubulin was similar to that in the control cultures. In contrast, very rare spreading cells and a small number of cells with filamentous actin and tubulin were detected after freezing in the presence of only non-penetrating cryoprotectants. The largest number of pigment cells was found in cultures frozen with trehalose or trehalose and dimethyl sulfoxide. The ability to induce the spicule formation was lost in the cells frozen only with non-penetrating cryoprotectants, while it was maximal in cultures frozen in a cryoprotective mixture containing both non-penetrating and penetrating cryoprotectants (particularly, when ethylene glycol was present). Using different markers for cell state assessment, an effective cryopreservation protocol for sea urchin cells was developed: three-step freezing with a low cooling rate (1-2°C/min) and a combination of non-penetrating and penetrating cryoprotectants made it possible to obtain a high level of cell viability (up to 65-80%). Copyright © 2015 Elsevier Inc. All rights reserved.

Structure and Reversibility of 2D von Neumann Cellular Automata Over Triangular Lattice

NASA Astrophysics Data System (ADS)

Uguz, Selman; Redjepov, Shovkat; Acar, Ecem; Akin, Hasan

2017-06-01

Even though the fundamental main structure of cellular automata (CA) is a discrete special model, the global behaviors at many iterative times and on big scales could be a close, nearly a continuous, model system. CA theory is a very rich and useful phenomena of dynamical model that focuses on the local information being relayed to the neighboring cells to produce CA global behaviors. The mathematical points of the basic model imply the computable values of the mathematical structure of CA. After modeling the CA structure, an important problem is to be able to move forwards and backwards on CA to understand their behaviors in more elegant ways. A possible case is when CA is to be a reversible one. In this paper, we investigate the structure and the reversibility of two-dimensional (2D) finite, linear, triangular von Neumann CA with null boundary case. It is considered on ternary field ℤ3 (i.e. 3-state). We obtain their transition rule matrices for each special case. For given special triangular information (transition) rule matrices, we prove which triangular linear 2D von Neumann CAs are reversible or not. It is known that the reversibility cases of 2D CA are generally a much challenged problem. In the present study, the reversibility problem of 2D triangular, linear von Neumann CA with null boundary is resolved completely over ternary field. As far as we know, there is no structure and reversibility study of von Neumann 2D linear CA on triangular lattice in the literature. Due to the main CA structures being sufficiently simple to investigate in mathematical ways, and also very complex to obtain in chaotic systems, it is believed that the present construction can be applied to many areas related to these CA using any other transition rules.

Transition-metal oxides with triangular lattices: generation of new magnetic and electronic properties.

PubMed

Maignan, A; Kobayashi, W; Hébert, S; Martinet, G; Pelloquin, D; Bellido, N; Simon, Ch

2008-10-06

The search for multifunctional materials as multiferroics to be applied in microelectronic or for new, chemically stable and nontoxic, thermoelectric materials to recover waste heat is showing a common interest in the oxides whose structures contain a triangular network of transition-metal cations. To illustrate this point, two ternary systems, Ba-Co-O and Ca-Co-O, have been chosen. It is shown that new phases with a complex triangular structure can be discovered, for instance, by introduction of Ga (3+) into the Ba-Co-O system to stabilize Ba 6Ga 2Co 11O 26 and Ba 2GaCo 8O 14, which both belong to a large family of compounds with formula [Ba(Co,Ga)O 3-delta] n [BaCo 8O 11]. In the latter, both sublattices contain triangular networks derived from the hexagonal perovskite and the spinel structure. Among the hexagonal perovskite, the Ca 3Co 2O 6 crystals give clear evidence where the coupling of charges and spins is at the origin of a magnetocapacitance effect. In particular, the ferrimagnetic to ferromagnetic transition, with a one-third plateau on the M( H) curve characteristic of triangular magnetism, is accompanied by a peak in the dielectric constant. A second class of cobaltites is the focus of much interest. Their 2D structure, containing CoO 2 planes isostructural to a CdI 2 slice that are stacked in an incommensurate way with rock salt type layers, is referred to misfit cobaltite. The 2D triangular network of edge-shared CoO 6 octahedra is believed to be responsible for large values of the Seebeck coefficient and low electrical resistivity. A clear relationship between the structuresincommensurability ratiosand the electronic properties is evidenced, showing that the charge carrier concentration can be tuned via the control of the ionic radius of the cations in the separating layers.

Using HMOs to serve the Medicaid population: what are the effects on utilization and does the type of HMO matter?

PubMed

Herring, Bradley; Adams, E Kathleen

2011-04-01

States have increasingly used Health Maintenance Organizations (HMOs) to provide medical services to the Medicaid population. However, the effects of these initiatives on total health-care expenses, the mix of utilization, and access to care remain unclear. We examine the effect of changes in Medicaid HMO penetration between 1996 and 2002 on these outcomes using data for the nonelderly Medicaid population in the Community Tracking Study's Household Survey. We develop market-level measures of Medicaid HMO penetration from CMS and InterStudy data, distinguish whether the HMOs specialize in serving the Medicaid population, and use a market fixed-effects model to focus on changes in HMO penetration rates over time. Although limited by imprecise estimates, we find some evidence that utilization and access are related to the market penetration rates of commercial and Medicaid-dominant HMOs, but the pattern of results we observe does not appear to be consistent with welfare improvements. Copyright © 2010 John Wiley & Sons, Ltd.

Combined Palmer Type 1A and 1B Traumatic Lesions of the Triangular Fibrocartilage Complex A New Category.

PubMed

Nance, Erin; Ayalon, Omri; Yang, Steven

2016-06-01

We present a series of eight patients who underwent wrist arthroscopy for presumed solitary tears of the triangular fibrocartilage (TFC) and were, instead, found to have combined 1A (central tear) and 1B (ulnar avulsion) tears. The Palmer Classification does not currently categorize this combined pattern. All but one patient had a traumatic injury. Each subject had preoperative radiographs and MRI scans. TFC tears were evident on all MRI scans, though only one was suggestive of a combined tear pat - tern. Surgical management included arthroscopic central tear debridement and ulnar peripheral repair. Average follow-up was 22 months. Grip strength in the affected hand improved from 16% deficit as compared to the unaffected side, to 3.5% deficit postoperatively (p = 0.003), and visual analog scores (VAS) decreased from an average of 7.1/10 preoperatively to 2.3/10 postoperatively (p < 0.001). There was no statistically significant change in wrist range of motion (ROM), however. Arthroscopic debridement of the central perforation (1A lesion) with concomitant repair of the ulnar detachment (1B lesion) resulted in functional and symptomatic improvement. This combined 1A/1B TFC injury is not reliably diagnosed preoperatively and should be considered a new subset in the Palmer classification, as this will raise awareness of its presence and assist in preoperative planning of such lesions.

Anomalous finite-size effect due to quasidegenerate phases in triangular antiferromagnets with long-range interactions and mapping to the generalized six-state clock model

NASA Astrophysics Data System (ADS)

Nishino, Masamichi; Miyashita, Seiji

2016-11-01

The effect of long-range (LR) interactions on frustrated-spin models is an interesting problem, which provides rich ordering processes. We study the effect of LR interactions on triangular Ising antiferromagnets with the next-nearest-neighbor ferromagnetic interaction (TIAFF). In the thermodynamic limit, the LRTIAFF model should reproduce the corresponding mean-field results, in which successive phase transitions occur among various phases, i.e., the disordered paramagnetic phase, so-called partially disordered phase, three-sublattice ferrimagnetic phase, and two-sublattice ferrimagnetic phase. In the present paper we focus on the magnetic susceptibility at the transition point between the two-sublattice ferrimagnetic and the disordered paramagnetic phases at relatively large ferromagnetic interactions. In the mean-field analysis, the magnetic susceptibility shows no divergence at the transition point. In contrast, a divergencelike enhancement of the susceptibility is observed in Monte Carlo simulations in finite-size systems. We investigate the origin of this difference and find that it is attributed to a virtual degeneracy of the free energies of the partially disordered and 2-FR phases. We also exploit a generalized six-state clock model with an LR interaction, which is a more general system with Z6 symmetry. We discuss the phase diagram of this model and find that it exhibits richer transition patterns and contains the physics of the LRTIAFF model.

Electronic confining effects in Sierpiński triangle fractals

NASA Astrophysics Data System (ADS)

Wang, Hao; Zhang, Xue; Jiang, Zhuoling; Wang, Yongfeng; Hou, Shimin

2018-03-01

Electron confinement in fractal Sierpiński triangles (STs) on Ag(111) is investigated using scanning tunneling spectroscopy and theoretically simulated by employing an improved two-dimensional (2D) multiple scattering theory in which the energy-dependent phase shifts are explicitly calculated from the electrostatic potentials of the molecular building block of STs. Well-defined bound surface states are observed in three kinds of triangular cavities with their sides changing at a scale factor of 2. The decrease in length of the cavities results in an upshift of the resonances that deviates from an expected inverse quadratic dependence on the cavity length due to the less efficient confinement of smaller triangular cavities. Differential conductance maps at some specific biases present a series of alternative bright and dark rounded triangles preserving the symmetry of the boundary. Our improved 2D multiple scattering model reproduces the characteristics of the standing wave patterns and all features in the differential conductance spectra measured in experiments, illustrating that the elastic loss boundary scattering dominates the resonance broadening in these ST quantum corrals. Moreover, the self-similar structure of STs, that a larger central cavity is surrounded by three smaller ones with a half side length, gives rise to interactions of surface states confined in neighboring cavities, which are helpful for the suppression of the linewidth in differential conductance spectra.

A neutron diffraction study of the magnetic phases of CsCuCl3 for in-plane fields up to 17 T

NASA Astrophysics Data System (ADS)

Stüßer, N.; Schotte, U.; Hoser, A.; Meschke, M.; Meißner, M.; Wosnitza, J.

2002-05-01

Neutron diffraction investigations have been performed to study the magnetization process of CsCuCl3 with the magnetic field aligned within the ab-plane. In zero field the stacked, triangular-lattice antiferromagnet (TLA) CsCuCl3 has a helical structure incommensurate in the chain direction normal to the ab-plane. The magnetic phase diagram was investigated from 2 K up to TN in fields up to 17 T. The phase line for the expected incommensurate-commensurate (IC-C) phase transition could be determined throughout the whole phase diagram. At low temperature the IC-C transition is roughly at half the saturation field HS. The neutron diffraction patterns were found to be well described by a sinusoidally modulated spiral in fields up to HS/3. The initial increase of the scattering intensity in rising field indicates a continuous reduction of the spin frustration on the triangular lattice. Between HS/3 and HS/2 a new phase occurs where the spiral vector has a plateau in its field dependence. Close to the IC-C transition a growing asymmetry of magnetic satellite-peak intensities indicates domain effects which are related to the lifting of the chiral degeneracy in the ab-plane in rising field. The phase diagram obtained has some similarities with those calculated for stacked TLAs by considering the effects of quantum and thermal fluctuations.

Heat transfer and pressure drop characteristics of the tube bank fin heat exchanger with fin punched with flow redistributors and curved triangular vortex generators

NASA Astrophysics Data System (ADS)

Liu, Song; Jin, Hua; Song, KeWei; Wang, LiangChen; Wu, Xiang; Wang, LiangBi

2017-10-01

The heat transfer performance of the tube bank fin heat exchanger is limited by the air-side thermal resistance. Thus, enhancing the air-side heat transfer is an effective method to improve the performance of the heat exchanger. A new fin pattern with flow redistributors and curved triangular vortex generators is experimentally studied in this paper. The effects of the flow redistributors located in front of the tube stagnation point and the curved vortex generators located around the tube on the characteristics of heat transfer and pressure drop are discussed in detail. A performance comparison is also carried out between the fins with and without flow redistributors. The experimental results show that the flow redistributors stamped out from the fin in front of the tube stagnation points can decrease the friction factor at the cost of decreasing the heat transfer performance. Whether the combination of the flow redistributors and the curved vortex generators will present a better heat transfer performance depends on the size of the curved vortex generators. As for the studied two sizes of vortex generators, the heat transfer performance is promoted by the flow redistributors for the fin with larger size of vortex generators and the performance is suppressed by the flow redistributors for the fin with smaller vortex generators.

Space Radar Image of Randonia Rain Cell

NASA Image and Video Library

1999-04-15

This multi-frequency space radar image of a tropical rainforest in western Brazil shows rapidly changing land use patterns and it also demonstrates the capability of the different radar frequencies to detect and penetrate heavy rainstorms.

Magnetic assembly and annealing of colloidal lattices and superlattices.

PubMed

Tierno, Pietro

2014-07-08

The ability to assemble mesoscopic colloidal lattices above a surface is important for fundamental studies related with nucleation and crystallization but also for a variety of technological applications in photonics and microengineering. Current techniques based on particle sedimentation above a lithographic template are limited by a slow deposition process and by the use of static templates, which make difficult to implement fast annealing procedures. Here it is demonstrated a method to realize and anneal a series of colloidal lattices displaying triangular, honeycomb, or kagome-like symmetry above a structure magnetic substrate. By using a binary mixture of particles, superlattices can be realized increasing further the variety and complexity of the colloidal patterns which can be produced.

Topological helical edge states in water waves over a topographical bottom

NASA Astrophysics Data System (ADS)

Wu, Shiqiao; Wu, Ying; Mei, Jun

2018-02-01

We present the discovery of topologically protected helical edge states in water wave systems, which are realized in water wave propagating over a topographical bottom whose height is modulated periodically in a two-dimensional triangular pattern. We develop an effective Hamiltonian to characterize the dispersion relation and use spin Chern numbers to classify the topology. Through full-wave simulations we unambiguously demonstrate the robustness of the helical edge states which are immune to defects and disorders so that the backscattering loss is significantly reduced. A spin splitter is designed for water wave systems, where helical edge states with different spin orientations are spatially separated with each other, and potential applications are discussed.

Optical fabrication of large area photonic microstructures by spliced lens

NASA Astrophysics Data System (ADS)

Jin, Wentao; Song, Meng; Zhang, Xuehua; Yin, Li; Li, Hong; Li, Lin

2018-05-01

We experimentally demonstrate a convenient approach to fabricate large area photorefractive photonic microstructures by a spliced lens device. Large area two-dimensional photonic microstructures are optically induced inside an iron-doped lithium niobate crystal. The experimental setups of our method are relatively compact and stable without complex alignment devices. It can be operated in almost any optical laboratories. We analyze the induced triangular lattice microstructures by plane wave guiding, far-field diffraction pattern imaging and Brillouin-zone spectroscopy. By designing the spliced lens appropriately, the method can be easily extended to fabricate other complex large area photonic microstructures, such as quasicrystal microstructures. Induced photonic microstructures can be fixed or erased and re-recorded in the photorefractive crystal.

Spin model for nontrivial types of magnetic order in inverse-perovskite antiferromagnets

NASA Astrophysics Data System (ADS)

Mochizuki, Masahito; Kobayashi, Masaya; Okabe, Reoya; Yamamoto, Daisuke

2018-02-01

Nontrivial magnetic orders in the inverse-perovskite manganese nitrides are theoretically studied by constructing a classical spin model describing the magnetic anisotropy and frustrated exchange interactions inherent in specific crystal and electronic structures of these materials. With a replica-exchange Monte Carlo technique, a theoretical analysis of this model reproduces the experimentally observed triangular Γ5 g and Γ4 g spin-ordered patterns and the systematic evolution of magnetic orders. Our Rapid Communication solves a 40-year-old problem of nontrivial magnetism for the inverse-perovskite manganese nitrides and provides a firm basis for clarifying the magnetism-driven negative thermal expansion phenomenon discovered in this class of materials.

Penetration of chemicals into the oocyte, uterine fluid, and preimplantation blastocyst

PubMed Central

Fabro, Sergio

1978-01-01

Chemicals, including commonly used drugs (e.g., penicillin, meprobamate, pyridium, and mercaptomerin) penetrate and persist for some time in the ovarian follicular fluid at concentrations approximately similar to that of the serum. Information as to the penetration of chemicals into the granulosa cells and into the oocyte is scanty, although there are some indications that these structures are also permeable to foreign chemicals. Similarly, caffeine, nicotine, thiopental, salicylic acid, antipyrine, barbital, and isoniazid enter the uterine secretion and penetrate the preimplantation blastocyst of mice, rats and rabbits. The pattern of distribution of compounds among ovarian follicular fluid, uterine luminal fluid, blastocyst and plasma varies from compound to compound and appears to be related to the molecular weight and degree of ionization of the compound and differs in pregnant and nonpregnant animals. Thus, nicotine and DDT accumulate in the uterine luminal fluid of pregnant but not in that of nonpregnant rabbits. The penetration of foreign chemicals into the oocyte, uterine luminal fluid, and preimplantation blastocyst may exert adverse effects on fertilization, implantation, and/or further development of the conceptus. The possible toxicological importance of this process to eutherian reproduction is discussed. PMID:17539150

The effect of longitudinal conductance variations on the ionospheric prompt penetration electric fields

NASA Astrophysics Data System (ADS)

Sazykin, S.; Wolf, R.; Spiro, R.; Fejer, B.

Ionospheric prompt penetration electric fields of magnetospheric origin, together with the atmospheric disturbance dynamo, represent the most important parameters controlling the storm-time dynamics of the low and mid-latitude ionosphere. These prompt penetration fields result from the disruption of region-2 field-aligned shielding currents during geomagnetically disturbed conditions. Penetration electric fields con- trol, to a large extent, the generation and development of equatorial spread-F plasma instabilities as well as other dynamic space weather phenomena in the ionosphere equatorward of the auroral zone. While modeling studies typically agree with average patterns of prompt penetration fields, experimental results suggest that longitudinal variations of the ionospheric con- ductivities play a non-negligible role in controlling spread-F phenomena, an effect that has not previously been modeled. We present first results of modeling prompt pene- tration electric fields using a version of the Rice Convection Model (RCM) that allows for longitudinal variations in the ionospheric conductance tensor. The RCM is a first- principles numerical ionosphere-magnetosphere coupling model that solves for the electric fields, field-aligned currents, and particle distributions in the ionosphere and inner/middle magnetosphere. We compare these new theoretical results with electric field observations.

Triangular Numbers, Gaussian Integers, and KenKen

ERIC Educational Resources Information Center

Watkins, John J.

2012-01-01

Latin squares form the basis for the recreational puzzles sudoku and KenKen. In this article we show how useful several ideas from number theory are in solving a KenKen puzzle. For example, the simple notion of triangular number is surprisingly effective. We also introduce a variation of KenKen that uses the Gaussian integers in order to…

Subjectivity, objectivity, and triangular space.

PubMed

Britton, Ronald

2004-01-01

The author reviews his ideas on subjectivity, objectivity, and the third position in the psychoanalytic encounter, particularly in clinical work with borderline and narcissistic patients. Using the theories of Melanie Klein and Wilfred Bion as a basis, the author describes his concept of triangular space. A case presentation of a particular type of narcissistic patient illustrates the principles discussed.

Gapless spin excitations in the S = 1 / 2 Kagome- and triangular-lattice Heisenberg antiferromagnets

NASA Astrophysics Data System (ADS)

Sakai, Tôru; Nakano, Hiroki

2018-05-01

The S = 1 / 2 kagome- and triangular-lattice Heisenberg antiferromagnets are investigated using the numerical exact diagonalization and the finite-size scaling analysis. The behaviour of the field derivative at zero magnetization is examined for both systems. The present result indicates that the spin excitation is gapless for each system.

Brief Report: Intimacy, Passion, and Commitment in Romantic Relationships--Validation of a "Triangular Love Scale" for Adolescents

ERIC Educational Resources Information Center

Overbeek, Geertjan; Ha, Thao; Scholte, Ron; de Kemp, Raymond; Engels, Rutger C. M. E.

2007-01-01

This study examined the psychometric properties of an adolescent version of the "triangular love scale" (TLS), which assesses three components of romantic relationships: intimacy, passion, and commitment. Using data from 435 Dutch adolescents aged 12-18 years, we found evidence for convergent validity, showing that dimensions of…

Triangular lattice atomic layer of Sn(1 × 1) at graphene/SiC(0001) interface

NASA Astrophysics Data System (ADS)

Hayashi, Shingo; Visikovskiy, Anton; Kajiwara, Takashi; Iimori, Takushi; Shirasawa, Tetsuroh; Nakastuji, Kan; Miyamachi, Toshio; Nakashima, Shuhei; Yaji, Koichiro; Mase, Kazuhiko; Komori, Fumio; Tanaka, Satoru

2018-01-01

Sn atomic layers attract considerable interest owing to their spin-related physical properties caused by their strong spin-orbit interactions. We performed Sn intercalation into the graphene/SiC(0001) interface and found a new type of Sn atomic layer. Sn atoms occupy on-top sites of Si-terminated SiC(0001) with in-plane Sn-Sn bondings, resulting in a triangular lattice. Angle-resolved photoemission spectroscopy revealed characteristic dispersions at \\bar{\\text{K}} and \\bar{\\text{M}} points, which agreed well with density functional theory calculations. The Sn triangular lattice atomic layer at the interface showed no oxidation upon exposure to air, which is useful for characterization and device fabrication ex situ.

Apex-angle-dependent resonances in triangular split-ring resonators

NASA Astrophysics Data System (ADS)

Burnett, Max A.; Fiddy, Michael A.

2016-02-01

Along with other frequency selective structures (Pendry et al. in IEEE Trans Microw Theory Tech 47(11):2075-2084, 1999) (circles and squares), triangular split-ring resonators (TSRRs) only allow frequencies near the center resonant frequency to propagate. Further, TSRRs are attractive due to their small surface area (Vidhyalakshmi et al. in Stopband characteristics of complementary triangular split ring resonator loaded microstrip line, 2011), comparatively, and large quality factors ( Q) as previously investigated by Gay-Balmaz et al. (J Appl Phys 92(5):2929-2936, 2002). In this work, we examine the effects of varying the apex angle on the resonant frequency, the Q factor, and the phase shift imparted by the TSRR element within the GHz frequency regime.

Self characterization of a coded aperture array for neutron source imaging

DOE PAGES

Volegov, P. L.; Danly, C. R.; Fittinghoff, D. N.; ...

2014-12-15

The neutron imaging system at the National Ignition Facility (NIF) is an important diagnostic tool for measuring the two-dimensional size and shape of the neutrons produced in the burning DT plasma during the stagnation stage of ICF implosions. Since the neutron source is small (~100 μm) and neutrons are deeply penetrating (>3 cm) in all materials, the apertures used to achieve the desired 10-μm resolution are 20-cm long, triangular tapers machined in gold foils. These gold foils are stacked to form an array of 20 apertures for pinhole imaging and three apertures for penumbral imaging. These apertures must be preciselymore » aligned to accurately place the field of view of each aperture at the design location, or the location of the field of view for each aperture must be measured. In this paper we present a new technique that has been developed for the measurement and characterization of the precise location of each aperture in the array. We present the detailed algorithms used for this characterization and the results of reconstructed sources from inertial confinement fusion implosion experiments at NIF.« less

Heterogeneous Mobile Phone Ownership and Usage Patterns in Kenya

PubMed Central

Wesolowski, Amy; Eagle, Nathan; Noor, Abdisalan M.; Snow, Robert W.; Buckee, Caroline O.

2012-01-01

The rapid adoption of mobile phone technologies in Africa is offering exciting opportunities for engaging with high-risk populations through mHealth programs, and the vast volumes of behavioral data being generated as people use their phones provide valuable data about human behavioral dynamics in these regions. Taking advantage of these opportunities requires an understanding of the penetration of mobile phones and phone usage patterns across the continent, but very little is known about the social and geographical heterogeneities in mobile phone ownership among African populations. Here, we analyze a survey of mobile phone ownership and usage across Kenya in 2009 and show that distinct regional, gender-related, and socioeconomic variations exist, with particularly low ownership among rural communities and poor people. We also examine patterns of phone sharing and highlight the contrasting relationships between ownership and sharing in different parts of the country. This heterogeneous penetration of mobile phones has important implications for the use of mobile technologies as a source of population data and as a public health tool in sub-Saharan Africa. PMID:22558140

Heterogeneous mobile phone ownership and usage patterns in Kenya.

PubMed

Wesolowski, Amy; Eagle, Nathan; Noor, Abdisalan M; Snow, Robert W; Buckee, Caroline O

2012-01-01

The rapid adoption of mobile phone technologies in Africa is offering exciting opportunities for engaging with high-risk populations through mHealth programs, and the vast volumes of behavioral data being generated as people use their phones provide valuable data about human behavioral dynamics in these regions. Taking advantage of these opportunities requires an understanding of the penetration of mobile phones and phone usage patterns across the continent, but very little is known about the social and geographical heterogeneities in mobile phone ownership among African populations. Here, we analyze a survey of mobile phone ownership and usage across Kenya in 2009 and show that distinct regional, gender-related, and socioeconomic variations exist, with particularly low ownership among rural communities and poor people. We also examine patterns of phone sharing and highlight the contrasting relationships between ownership and sharing in different parts of the country. This heterogeneous penetration of mobile phones has important implications for the use of mobile technologies as a source of population data and as a public health tool in sub-Saharan Africa.

Effect of triangular texture on the tribological performance of die steel with TiN coatings under lubricated sliding condition

NASA Astrophysics Data System (ADS)

Chen, Ping; Xiang, Xin; Shao, Tianmin; La, Yingqian; Li, Junling

2016-12-01

The friction and wear of stamping die surface can affect the service life of stamping die and the quality of stamping products. Surface texturing and surface coating have been widely used to improve the tribological performance of mechanical components. This study experimentally investigated the effect of triangular surface texture on the friction and wear properties of the die steel substrate with TiN coatings under oil lubrication. TiN coatings were deposited on a die steel (50Cr) substrate through a multi-arc ion deposition system, and then triangular surface texturing was fabricated by a laser surface texturing. The friction and wear test was conducted by a UMT-3 pin-on-disk tribometer under different sliding speeds and different applied loads, respectively. The adhesion test was performed to evaluate the effectiveness of triangular texturing on the interfacial bonding strength between the TiN coating and the die steel substrate. Results show that the combination method of surface texturing process and surface coating process has excellent tribological properties (the lowest frictional coefficient and wear volume), compared with the single texturing process or the single coating process. The tribological performance is improved resulting from the high hardness and low elastic modulus of TiN coatings, and the generation of hydrodynamic pressure, function of micro-trap for wear debris and micro-reservoirs for lubricating oil of the triangular surface texture. In addition, the coating bonding strength of the texturing sample is 3.63 MPa, higher than that of the single coating sample (3.48 MPa), but the mechanisms remain to be further researched.

Theory-based model for the pedestal, edge stability and ELMs in tokamaks

NASA Astrophysics Data System (ADS)

Pankin, A. Y.; Bateman, G.; Brennan, D. P.; Schnack, D. D.; Snyder, P. B.; Voitsekhovitch, I.; Kritz, A. H.; Janeschitz, G.; Kruger, S.; Onjun, T.; Pacher, G. W.; Pacher, H. D.

2006-04-01

An improved model for triggering edge localized mode (ELM) crashes is developed for use within integrated modelling simulations of the pedestal and ELM cycles at the edge of H-mode tokamak plasmas. The new model is developed by using the BALOO, DCON and ELITE ideal MHD stability codes to derive parametric expressions for the ELM triggering threshold. The whole toroidal mode number spectrum is studied with these codes. The DCON code applies to low mode numbers, while the BALOO code applies to only high mode numbers and the ELITE code applies to intermediate and high mode numbers. The variables used in the parametric stability expressions are the normalized pressure gradient and the parallel current density, which drive ballooning and peeling modes. Two equilibria motivated by DIII-D geometry with different plasma triangularities are studied. It is found that the stable region in the high triangularity discharge covers a much larger region of parameter space than the corresponding stability region in the low triangularity discharge. The new ELM trigger model is used together with a previously developed model for pedestal formation and ELM crashes in the ASTRA integrated modelling code to follow the time evolution of the temperature profiles during ELM cycles. The ELM frequencies obtained in the simulations of low and high triangularity discharges are observed to increase with increasing heating power. There is a transition from second stability to first ballooning mode stability as the heating power is increased in the high triangularity simulations. The results from the ideal MHD stability codes are compared with results from the resistive MHD stability code NIMROD.

The impact of a shallow biobarrier on water recharge patterns in a semi-arid environment

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

Laundre, J.W.

1997-12-31

This study attempted to measure the effect of a shallow biobarrier of gravel and cobble on water flow patterns during spring snow melt and recharge. The design consisted of 30 metal culverts 3 m in diameter and 1.6 m long, positioned on end. Test culverts contained 50-cm biobarrier of gravel or cobble and then an additional 50 cm of soil placed above the barrier layer. A neutron probe was used to measure soil moisture above and below the barrier. Measurements were made in the fall and again immediately after snow melt in the spring. During recharge, the biobarriers provided amore » capillary break which resulted in a pooling of water above the barrier layer. With sufficient snowmelt, the water can penetrate the break and possibly penetrate deeper than in the absence of the barrier layer.« less

Direct-strike lightning photographs, swept-flash attachment patterns, and flight conditions for storm hazards 1982

NASA Technical Reports Server (NTRS)

Zaepfel, K. P.; Fisher, B. D.; Ott, M. S.

1985-01-01

As part of the NASA Langley Research Center Storm Hazards Program, 241 thunderstorm penetrations were made in 1982 with an F-106B airplane in order to record direct-strike lightning data and the associated flight conditions. During these penetrations, the airplane received 156 direct lightning strikes; in addition, lightning transient data were recorded from 26 nearby lightning flashes. The tests were conducted within 150 nautical miles of Hampton, Virginia, assisted by ground-based weather-radar guidance from the NASA Wallops Flight Facility. The photographs of the lightning attachments taken from two onboard 16-mm color movie cameras and the associated strike attachment patterns are presented. A table of the flight conditions recorded at the time of each lightning event, and a table in which the data are cross-referenced with the previously published lightning electromagnetic waveform data are included.

On the local time dependence of the bow shock wave structure

NASA Technical Reports Server (NTRS)

Olson, J. V.; Holzer, R. E.

1974-01-01

In the first 6 months after its launch, Ogo 3 crossed the earth's bow shock over 500 times. From this group, a set of 494 shock crossings were chosen for analysis. These crossings, as they were recorded by the UCLA/JPL search coil magnetometer, were scanned and classified according to the nature of the plasma waves detected near the shock. More than 85% of the shocks detected fell into a single category showing the predominance of two independent wave trains near the shock, the higher frequency appearing upstream and the lower downstream. The other 15%, which constitute an upper limit, appear to be composed of shocks dominated by a single wave pattern and of chaotic shocks showing no orderly progression of wave frequencies as the shock was penetrated. This division of wave pattern was found to occur at all local times, that is, in all regions where the satellite penetrated the shock.

Changing pattern and outcome of pediatric chest injuries in urban Syria.

PubMed

Darwish, Bassam; Mahfouz, Mohammad Z; Al-Nosairat, Saeed; Izzat, Mohammad Bashar

2018-01-01

Background Pediatric chest injuries were infrequent in our practice, but the outbreak of the Syrian crisis resulted in an increase in number and a change in the pattern of thoracic trauma incidents. We compared our experience of pediatric chest injuries before and during the crisis. Methods We reviewed the records of 256 children aged 12.8 ± 5 years who were admitted to our hospital with the diagnosis of chest trauma over a 12-year period. Collected data included mechanism of injury, associated injuries, method of management, length of hospital stay, complications, and mortality. Results The incidence of pediatric chest injuries increased significantly following the outbreak of the crisis, and penetrating injuries prevailed, mainly due to shrapnel, bullets, and stab wounds. Forty percent of patients with blunt injuries and 20% of those with penetrating injuries were managed conservatively, whereas urgent thoracotomies were indicated in 10%, mostly in patients with penetrating injuries. Associated injuries were more frequent in patients with blunt injuries and resulted in a longer hospital stay and an increased mortality rate. The overall mortality rate was 7.8% and it was higher in children younger than 7 years of age and in patients who had been subjected to blunt injuries. Conclusions There has been a recent substantial upsurge in the incidence of pediatric thoracic trauma, with a predominance of penetrating injuries. Most patients could be managed nonoperatively, but a small subset required an open thoracotomy. The presence of associated injuries constitutes the main determinant of prognosis in this group of patients.

Middle Passage in the Triangular Slave Trade: The West Indies

ERIC Educational Resources Information Center

Sawh, Ruth; Scales, Alice M.

2006-01-01

Our narrative focuses on the middle passage of the slave trade in the West Indies. Herein we describe why more men, women, and children were imported in the West Indies than other islands. Specifically, our aim was to address how slaves in the middle passage of the triangular slave trade were treated, how they sustained themselves, and how they…

A mesh regeneration method using quadrilateral and triangular elements for compressible flows

NASA Technical Reports Server (NTRS)

Vemaganti, G. R.; Thornton, E. A.

1989-01-01

An adaptive remeshing method using both triangular and quadrilateral elements suitable for high-speed viscous flows is presented. For inviscid flows, the method generates completely unstructured meshes. For viscous flows, structured meshes are generated for boundary layers, and unstructured meshes are generated for inviscid flow regions. Examples of inviscid and viscous adaptations for high-speed flows are presented.

Experimental Study of Floating-Gate-Type Metal-Oxide-Semiconductor Capacitors with Nanosize Triangular Cross-Sectional Tunnel Areas for Low Operating Voltage Flash Memory Application

NASA Astrophysics Data System (ADS)

Liu, Yongxun; Guo, Ruofeng; Kamei, Takahiro; Matsukawa, Takashi; Endo, Kazuhiko; O'uchi, Shinichi; Tsukada, Junichi; Yamauchi, Hiromi; Ishikawa, Yuki; Hayashida, Tetsuro; Sakamoto, Kunihiro; Ogura, Atsushi; Masahara, Meishoku

2012-06-01

The floating-gate (FG)-type metal-oxide-semiconductor (MOS) capacitors with planar (planar-MOS) and three-dimensional (3D) nanosize triangular cross-sectional tunnel areas (3D-MOS) have successfully been fabricated by introducing rapid thermal oxidation (RTO) and postdeposition annealing (PDA), and their electrical characteristics between the control gate (CG) and FG have been systematically compared. It was experimentally found in both planar- and 3D-MOS capacitors that the uniform and higher breakdown voltages are obtained by introducing RTO owing to the high-quality thermal oxide formation on the surface and etched edge regions of the n+ polycrystalline silicon (poly-Si) FG, and the leakage current is highly suppressed after PDA owing to the improved quality of the tetraethylorthosilicate (TEOS) silicon dioxide (SiO2) between CG and FG. Moreover, a lower breakdown voltage between CG and FG was obtained in the fabricated 3D-MOS capacitors as compared with that of planar-MOS capacitors thanks to the enhanced local electric field at the tips of triangular tunnel areas. The developed nanosize triangular cross-sectional tunnel area is useful for the fabrication of low operating voltage flash memories.

Measurements of Elliptic and Triangular Flow in High-Multiplicity 3He+Au Collisions at √(s(NN))=200 GeV.

PubMed

Adare, A; Afanasiev, S; Aidala, C; Ajitanand, N N; Akiba, Y; Akimoto, R; Al-Bataineh, H; Alexander, J; Alfred, M; Al-Ta'ani, H; Andrews, K R; Angerami, A; Aoki, K; Apadula, N; Aphecetche, L; Appelt, E; Aramaki, Y; Armendariz, R; Aronson, S H; Asai, J; Asano, H; Aschenauer, E C; Atomssa, E T; Averbeck, R; Awes, T C; Azmoun, B; Babintsev, V; Bai, M; Baksay, G; Baksay, L; Baldisseri, A; Bandara, N S; Bannier, B; Barish, K N; Barnes, P D; Bassalleck, B; Basye, A T; Bathe, S; Batsouli, S; Baublis, V; Baumann, C; Bazilevsky, A; Beaumier, M; Beckman, S; Belikov, S; Belmont, R; Ben-Benjamin, J; Bennett, R; Berdnikov, A; Berdnikov, Y; Bhom, J H; Bickley, A A; Blau, D S; Boissevain, J G; Bok, J S; Borel, H; Boyle, K; Brooks, M L; Broxmeyer, D; Bryslawskyj, J; Buesching, H; Bumazhnov, V; Bunce, G; Butsyk, S; Camacho, C M; Campbell, S; Caringi, A; Castera, P; Chang, B S; Chang, W C; Charvet, J-L; Chen, C-H; Chernichenko, S; Chi, C Y; Chiba, J; Chiu, M; Choi, I J; Choi, J B; Choudhury, R K; Christiansen, P; Chujo, T; Chung, P; Churyn, A; Chvala, O; Cianciolo, V; Citron, Z; Cleven, C R; Cole, B A; Comets, M P; Conesa del Valle, Z; Connors, M; Constantin, P; Csanád, M; Csörgő, T; Dahms, T; Dairaku, S; Danchev, I; Danley, D; Das, K; Datta, A; Daugherity, M S; David, G; Dayananda, M K; Deaton, M B; DeBlasio, K; Dehmelt, K; Delagrange, H; Denisov, A; d'Enterria, D; Deshpande, A; Desmond, E J; Dharmawardane, K V; Dietzsch, O; Dion, A; Diss, P B; Do, J H; Donadelli, M; D'Orazio, L; Drapier, O; Drees, A; Drees, K A; Dubey, A K; Durham, J M; Durum, A; Dutta, D; Dzhordzhadze, V; Edwards, S; Efremenko, Y V; Egdemir, J; Ellinghaus, F; Emam, W S; Engelmore, T; Enokizono, A; En'yo, H; Esumi, S; Eyser, K O; Fadem, B; Feege, N; Fields, D E; Finger, M; Finger, M; Fleuret, F; Fokin, S L; Fraenkel, Z; Frantz, J E; Franz, A; Frawley, A D; Fujiwara, K; Fukao, Y; Fusayasu, T; Gadrat, S; Gal, C; Gallus, P; Garg, P; Garishvili, I; Ge, H; Giordano, F; Glenn, A; Gong, H; Gong, X; Gonin, M; Gosset, J; Goto, Y; Granier de Cassagnac, R; Grau, N; Greene, S V; Grim, G; Grosse Perdekamp, M; Gu, Y; Gunji, T; Guo, L; Gustafsson, H-Å; Hachiya, T; Hadj Henni, A; Haegemann, C; Haggerty, J S; Hahn, K I; Hamagaki, H; Hamblen, J; Hamilton, H F; Han, R; Han, S Y; Hanks, J; Harada, H; Harper, C; Hartouni, E P; Haruna, K; Hasegawa, S; Haseler, T O S; Hashimoto, K; Haslum, E; Hayano, R; He, X; Heffner, M; Hemmick, T K; Hester, T; Hiejima, H; Hill, J C; Hobbs, R; Hohlmann, M; Hollis, R S; Holzmann, W; Homma, K; Hong, B; Horaguchi, T; Hori, Y; Hornback, D; Hoshino, T; Hotvedt, N; Huang, J; Huang, S; Ichihara, T; Ichimiya, R; Iinuma, H; Ikeda, Y; Imai, K; Imrek, J; Inaba, M; Inoue, Y; Iordanova, A; Isenhower, D; Isenhower, L; Ishihara, M; Isobe, T; Issah, M; Isupov, A; Ivanishchev, D; Iwanaga, Y; Jacak, B V; Jezghani, M; Jia, J; Jiang, X; Jin, J; Jinnouchi, O; John, D; Johnson, B M; Jones, T; Joo, K S; Jouan, D; Jumper, D S; Kajihara, F; Kametani, S; Kamihara, N; Kamin, J; Kanda, S; Kaneta, M; Kaneti, S; Kang, B H; Kang, J H; Kang, J S; Kanou, H; Kapustinsky, J; Karatsu, K; Kasai, M; Kawall, D; Kawashima, M; Kazantsev, A V; Kempel, T; Key, J A; Khachatryan, V; Khanzadeev, A; Kijima, K M; Kikuchi, J; Kim, A; Kim, B I; Kim, C; Kim, D H; Kim, D J; Kim, E; Kim, E-J; Kim, G W; Kim, M; Kim, S H; Kim, Y-J; Kim, Y K; Kimelman, B; Kinney, E; Kiriluk, K; Kiss, Á; Kistenev, E; Kitamura, R; Kiyomichi, A; Klatsky, J; Klay, J; Klein-Boesing, C; Kleinjan, D; Kline, P; Koblesky, T; Kochenda, L; Kochetkov, V; Komkov, B; Konno, M; Koster, J; Kotchetkov, D; Kotov, D; Kozlov, A; Král, A; Kravitz, A; Kubart, J; Kunde, G J; Kurihara, N; Kurita, K; Kurosawa, M; Kweon, M J; Kwon, Y; Kyle, G S; Lacey, R; Lai, Y S; Lajoie, J G; Layton, D; Lebedev, A; Lee, D M; Lee, J; Lee, K B; Lee, K S; Lee, M K; Lee, S; Lee, S H; Lee, S R; Lee, T; Leitch, M J; Leite, M A L; Lenzi, B; Li, X; Lichtenwalner, P; Liebing, P; Lim, S H; Linden Levy, L A; Liška, T; Litvinenko, A; Liu, H; Liu, M X; Love, B; Lynch, D; Maguire, C F; Makdisi, Y I; Makek, M; Malakhov, A; Malik, M D; Manion, A; Manko, V I; Mannel, E; Mao, Y; Mašek, L; Masui, H; Matathias, F; McCumber, M; McGaughey, P L; McGlinchey, D; McKinney, C; Means, N; Meles, A; Mendoza, M; Meredith, B; Miake, Y; Mibe, T; Mignerey, A C; Mikeš, P; Miki, K; Miller, T E; Milov, A; Mioduszewski, S; Mishra, D K; Mishra, M; Mitchell, J T; Mitrovski, M; Miyachi, Y; Miyasaka, S; Mizuno, S; Mohanty, A K; Montuenga, P; Moon, H J; Moon, T; Morino, Y; Morreale, A; Morrison, D P; Motschwiller, S; Moukhanova, T V; Mukhopadhyay, D; Murakami, T; Murata, J; Mwai, A; Nagamiya, S; Nagashima, K; Nagata, Y; Nagle, J L; Naglis, M; Nagy, M I; Nakagawa, I; Nakagomi, H; Nakamiya, Y; Nakamura, K R; Nakamura, T; Nakano, K; Nam, S; Nattrass, C; Netrakanti, P K; Newby, J; Nguyen, M; Nihashi, M; Niida, T; Nishimura, S; Norman, B E; Nouicer, R; Novak, T; Novitzky, N; Nyanin, A S; Oakley, C; O'Brien, E; Oda, S X; Ogilvie, C A; Ohnishi, H; Oka, M; Okada, K; Omiwade, O O; Onuki, Y; Orjuela Koop, J D; Osborn, J D; Oskarsson, A; Ouchida, M; Ozawa, K; Pak, R; Pal, D; Palounek, A P T; Pantuev, V; Papavassiliou, V; Park, B H; Park, I H; Park, J; Park, J S; Park, S; Park, S K; Park, W J; Pate, S F; Patel, L; Patel, M; Pei, H; Peng, J-C; Pereira, H; Perepelitsa, D V; Perera, G D N; Peresedov, V; Peressounko, D Yu; Perry, J; Petti, R; Pinkenburg, C; Pinson, R; Pisani, R P; Proissl, M; Purschke, M L; Purwar, A K; Qu, H; Rak, J; Rakotozafindrabe, A; Ramson, B J; Ravinovich, I; Read, K F; Rembeczki, S; Reuter, M; Reygers, K; Reynolds, D; Riabov, V; Riabov, Y; Richardson, E; Rinn, T; Roach, D; Roche, G; Rolnick, S D; Romana, A; Rosati, M; Rosen, C A; Rosendahl, S S E; Rosnet, P; Rowan, Z; Rubin, J G; Rukoyatkin, P; Ružička, P; Rykov, V L; Sahlmueller, B; Saito, N; Sakaguchi, T; Sakai, S; Sakashita, K; Sakata, H; Sako, H; Samsonov, V; Sano, S; Sarsour, M; Sato, S; Sato, T; Savastio, M; Sawada, S; Schaefer, B; Schmoll, B K; Sedgwick, K; Seele, J; Seidl, R; Semenov, A Yu; Semenov, V; Sen, A; Seto, R; Sett, P; Sexton, A; Sharma, D; Shein, I; Shevel, A; Shibata, T-A; Shigaki, K; Shim, H H; Shimomura, M; Shoji, K; Shukla, P; Sickles, A; Silva, C L; Silvermyr, D; Silvestre, C; Sim, K S; Singh, B K; Singh, C P; Singh, V; Skutnik, S; Slunečka, M; Snowball, M; Sodre, T; Soldatov, A; Soltz, R A; Sondheim, W E; Sorensen, S P; Sourikova, I V; Staley, F; Stankus, P W; Stenlund, E; Stepanov, M; Ster, A; Stoll, S P; Sugitate, T; Suire, C; Sukhanov, A; Sumita, T; Sun, J; Sziklai, J; Tabaru, T; Takagi, S; Takagui, E M; Takahara, A; Taketani, A; Tanabe, R; Tanaka, Y; Taneja, S; Tanida, K; Tannenbaum, M J; Tarafdar, S; Taranenko, A; Tarján, P; Tennant, E; Themann, H; Thomas, D; Thomas, T L; Tieulent, R; Timilsina, A; Todoroki, T; Togawa, M; Toia, A; Tojo, J; Tomášek, L; Tomášek, M; Tomita, Y; Torii, H; Towell, C L; Towell, R; Towell, R S; Tram, V-N; Tserruya, I; Tsuchimoto, Y; Utsunomiya, K; Vale, C; Valle, H; van Hecke, H W; Vazquez-Zambrano, E; Veicht, A; Velkovska, J; Vértesi, R; Vinogradov, A A; Virius, M; Vossen, A; Vrba, V; Vznuzdaev, E; Wagner, M; Walker, D; Wang, X R; Watanabe, D; Watanabe, K; Watanabe, Y; Watanabe, Y S; Wei, F; Wei, R; Wessels, J; White, A S; White, S N; Winter, D; Woody, C L; Wright, R M; Wysocki, M; Xia, B; Xie, W; Xue, L; Yalcin, S; Yamaguchi, Y L; Yamaura, K; Yang, R; Yanovich, A; Yasin, Z; Ying, J; Yokkaichi, S; Yoo, J H; Yoo, J S; Yoon, I; You, Z; Young, G R; Younus, I; Yu, H; Yushmanov, I E; Zajc, W A; Zaudtke, O; Zelenski, A; Zhang, C; Zhou, S; Zimamyi, J; Zolin, L; Zou, L

2015-10-02

We present the first measurement of elliptic (v(2)) and triangular (v(3)) flow in high-multiplicity (3)He+Au collisions at √(s(NN))=200  GeV. Two-particle correlations, where the particles have a large separation in pseudorapidity, are compared in (3)He+Au and in p+p collisions and indicate that collective effects dominate the second and third Fourier components for the correlations observed in the (3)He+Au system. The collective behavior is quantified in terms of elliptic v(2) and triangular v(3) anisotropy coefficients measured with respect to their corresponding event planes. The v(2) values are comparable to those previously measured in d+Au collisions at the same nucleon-nucleon center-of-mass energy. Comparisons with various theoretical predictions are made, including to models where the hot spots created by the impact of the three (3)He nucleons on the Au nucleus expand hydrodynamically to generate the triangular flow. The agreement of these models with data may indicate the formation of low-viscosity quark-gluon plasma even in these small collision systems.

Measurements of Elliptic and Triangular Flow in High-Multiplicity 3He +Au Collisions at √{sN N }=200 GeV

NASA Astrophysics Data System (ADS)

Adare, A.; Afanasiev, S.; Aidala, C.; Ajitanand, N. N.; Akiba, Y.; Akimoto, R.; Al-Bataineh, H.; Alexander, J.; Alfred, M.; Al-Ta'Ani, H.; Andrews, K. R.; Angerami, A.; Aoki, K.; Apadula, N.; Aphecetche, L.; Appelt, E.; Aramaki, Y.; Armendariz, R.; Aronson, S. H.; Asai, J.; Asano, H.; Aschenauer, E. C.; Atomssa, E. T.; Averbeck, R.; Awes, T. C.; Azmoun, B.; Babintsev, V.; Bai, M.; Baksay, G.; Baksay, L.; Baldisseri, A.; Bandara, N. S.; Bannier, B.; Barish, K. N.; Barnes, P. D.; Bassalleck, B.; Basye, A. T.; Bathe, S.; Batsouli, S.; Baublis, V.; Baumann, C.; Bazilevsky, A.; Beaumier, M.; Beckman, S.; Belikov, S.; Belmont, R.; Ben-Benjamin, J.; Bennett, R.; Berdnikov, A.; Berdnikov, Y.; Bhom, J. H.; Bickley, A. A.; Blau, D. S.; Boissevain, J. G.; Bok, J. S.; Borel, H.; Boyle, K.; Brooks, M. L.; Broxmeyer, D.; Bryslawskyj, J.; Buesching, H.; Bumazhnov, V.; Bunce, G.; Butsyk, S.; Camacho, C. M.; Campbell, S.; Caringi, A.; Castera, P.; Chang, B. S.; Chang, W. C.; Charvet, J.-L.; Chen, C.-H.; Chernichenko, S.; Chi, C. Y.; Chiba, J.; Chiu, M.; Choi, I. J.; Choi, J. B.; Choudhury, R. K.; Christiansen, P.; Chujo, T.; Chung, P.; Churyn, A.; Chvala, O.; Cianciolo, V.; Citron, Z.; Cleven, C. R.; Cole, B. A.; Comets, M. P.; Conesa Del Valle, Z.; Connors, M.; Constantin, P.; Csanád, M.; Csörgő, T.; Dahms, T.; Dairaku, S.; Danchev, I.; Danley, D.; Das, K.; Datta, A.; Daugherity, M. S.; David, G.; Dayananda, M. K.; Deaton, M. B.; Deblasio, K.; Dehmelt, K.; Delagrange, H.; Denisov, A.; D'Enterria, D.; Deshpande, A.; Desmond, E. J.; Dharmawardane, K. V.; Dietzsch, O.; Dion, A.; Diss, P. B.; Do, J. H.; Donadelli, M.; D'Orazio, L.; Drapier, O.; Drees, A.; Drees, K. A.; Dubey, A. K.; Durham, J. M.; Durum, A.; Dutta, D.; Dzhordzhadze, V.; Edwards, S.; Efremenko, Y. V.; Egdemir, J.; Ellinghaus, F.; Emam, W. S.; Engelmore, T.; Enokizono, A.; En'yo, H.; Esumi, S.; Eyser, K. O.; Fadem, B.; Feege, N.; Fields, D. E.; Finger, M.; Finger, M.; Fleuret, F.; Fokin, S. L.; Fraenkel, Z.; Frantz, J. E.; Franz, A.; Frawley, A. D.; Fujiwara, K.; Fukao, Y.; Fusayasu, T.; Gadrat, S.; Gal, C.; Gallus, P.; Garg, P.; Garishvili, I.; Ge, H.; Giordano, F.; Glenn, A.; Gong, H.; Gong, X.; Gonin, M.; Gosset, J.; Goto, Y.; Granier de Cassagnac, R.; Grau, N.; Greene, S. V.; Grim, G.; Grosse Perdekamp, M.; Gu, Y.; Gunji, T.; Guo, L.; Gustafsson, H.-Å.; Hachiya, T.; Hadj Henni, A.; Haegemann, C.; Haggerty, J. S.; Hahn, K. I.; Hamagaki, H.; Hamblen, J.; Hamilton, H. F.; Han, R.; Han, S. Y.; Hanks, J.; Harada, H.; Harper, C.; Hartouni, E. P.; Haruna, K.; Hasegawa, S.; Haseler, T. O. S.; Hashimoto, K.; Haslum, E.; Hayano, R.; He, X.; Heffner, M.; Hemmick, T. K.; Hester, T.; Hiejima, H.; Hill, J. C.; Hobbs, R.; Hohlmann, M.; Hollis, R. S.; Holzmann, W.; Homma, K.; Hong, B.; Horaguchi, T.; Hori, Y.; Hornback, D.; Hoshino, T.; Hotvedt, N.; Huang, J.; Huang, S.; Ichihara, T.; Ichimiya, R.; Iinuma, H.; Ikeda, Y.; Imai, K.; Imrek, J.; Inaba, M.; Inoue, Y.; Iordanova, A.; Isenhower, D.; Isenhower, L.; Ishihara, M.; Isobe, T.; Issah, M.; Isupov, A.; Ivanishchev, D.; Iwanaga, Y.; Jacak, B. V.; Jezghani, M.; Jia, J.; Jiang, X.; Jin, J.; Jinnouchi, O.; John, D.; Johnson, B. M.; Jones, T.; Joo, K. S.; Jouan, D.; Jumper, D. S.; Kajihara, F.; Kametani, S.; Kamihara, N.; Kamin, J.; Kanda, S.; Kaneta, M.; Kaneti, S.; Kang, B. H.; Kang, J. H.; Kang, J. S.; Kanou, H.; Kapustinsky, J.; Karatsu, K.; Kasai, M.; Kawall, D.; Kawashima, M.; Kazantsev, A. V.; Kempel, T.; Key, J. A.; Khachatryan, V.; Khanzadeev, A.; Kijima, K. M.; Kikuchi, J.; Kim, A.; Kim, B. I.; Kim, C.; Kim, D. H.; Kim, D. J.; Kim, E.; Kim, E.-J.; Kim, G. W.; Kim, M.; Kim, S. H.; Kim, Y.-J.; Kim, Y. K.; Kimelman, B.; Kinney, E.; Kiriluk, K.; Kiss, Á.; Kistenev, E.; Kitamura, R.; Kiyomichi, A.; Klatsky, J.; Klay, J.; Klein-Boesing, C.; Kleinjan, D.; Kline, P.; Koblesky, T.; Kochenda, L.; Kochetkov, V.; Komkov, B.; Konno, M.; Koster, J.; Kotchetkov, D.; Kotov, D.; Kozlov, A.; Král, A.; Kravitz, A.; Kubart, J.; Kunde, G. J.; Kurihara, N.; Kurita, K.; Kurosawa, M.; Kweon, M. J.; Kwon, Y.; Kyle, G. S.; Lacey, R.; Lai, Y. S.; Lajoie, J. G.; Layton, D.; Lebedev, A.; Lee, D. M.; Lee, J.; Lee, K. B.; Lee, K. S.; Lee, M. K.; Lee, S.; Lee, S. H.; Lee, S. R.; Lee, T.; Leitch, M. J.; Leite, M. A. L.; Lenzi, B.; Li, X.; Lichtenwalner, P.; Liebing, P.; Lim, S. H.; Linden Levy, L. A.; Liška, T.; Litvinenko, A.; Liu, H.; Liu, M. X.; Love, B.; Lynch, D.; Maguire, C. F.; Makdisi, Y. I.; Makek, M.; Malakhov, A.; Malik, M. D.; Manion, A.; Manko, V. I.; Mannel, E.; Mao, Y.; Mašek, L.; Masui, H.; Matathias, F.; McCumber, M.; McGaughey, P. L.; McGlinchey, D.; McKinney, C.; Means, N.; Meles, A.; Mendoza, M.; Meredith, B.; Miake, Y.; Mibe, T.; Mignerey, A. C.; Mikeš, P.; Miki, K.; Miller, T. E.; Milov, A.; Mioduszewski, S.; Mishra, D. K.; Mishra, M.; Mitchell, J. T.; Mitrovski, M.; Miyachi, Y.; Miyasaka, S.; Mizuno, S.; Mohanty, A. K.; Montuenga, P.; Moon, H. J.; Moon, T.; Morino, Y.; Morreale, A.; Morrison, D. P.; Motschwiller, S.; Moukhanova, T. V.; Mukhopadhyay, D.; Murakami, T.; Murata, J.; Mwai, A.; Nagamiya, S.; Nagashima, K.; Nagata, Y.; Nagle, J. L.; Naglis, M.; Nagy, M. I.; Nakagawa, I.; Nakagomi, H.; Nakamiya, Y.; Nakamura, K. R.; Nakamura, T.; Nakano, K.; Nam, S.; Nattrass, C.; Netrakanti, P. K.; Newby, J.; Nguyen, M.; Nihashi, M.; Niida, T.; Nishimura, S.; Norman, B. E.; Nouicer, R.; Novak, T.; Novitzky, N.; Nyanin, A. S.; Oakley, C.; O'Brien, E.; Oda, S. X.; Ogilvie, C. A.; Ohnishi, H.; Oka, M.; Okada, K.; Omiwade, O. O.; Onuki, Y.; Orjuela Koop, J. D.; Osborn, J. D.; Oskarsson, A.; Ouchida, M.; Ozawa, K.; Pak, R.; Pal, D.; Palounek, A. P. T.; Pantuev, V.; Papavassiliou, V.; Park, B. H.; Park, I. H.; Park, J.; Park, J. S.; Park, S.; Park, S. K.; Park, W. J.; Pate, S. F.; Patel, L.; Patel, M.; Pei, H.; Peng, J.-C.; Pereira, H.; Perepelitsa, D. V.; Perera, G. D. N.; Peresedov, V.; Peressounko, D. Yu.; Perry, J.; Petti, R.; Pinkenburg, C.; Pinson, R.; Pisani, R. P.; Proissl, M.; Purschke, M. L.; Purwar, A. K.; Qu, H.; Rak, J.; Rakotozafindrabe, A.; Ramson, B. J.; Ravinovich, I.; Read, K. F.; Rembeczki, S.; Reuter, M.; Reygers, K.; Reynolds, D.; Riabov, V.; Riabov, Y.; Richardson, E.; Rinn, T.; Roach, D.; Roche, G.; Rolnick, S. D.; Romana, A.; Rosati, M.; Rosen, C. A.; Rosendahl, S. S. E.; Rosnet, P.; Rowan, Z.; Rubin, J. G.; Rukoyatkin, P.; Ružička, P.; Rykov, V. L.; Sahlmueller, B.; Saito, N.; Sakaguchi, T.; Sakai, S.; Sakashita, K.; Sakata, H.; Sako, H.; Samsonov, V.; Sano, S.; Sarsour, M.; Sato, S.; Sato, T.; Savastio, M.; Sawada, S.; Schaefer, B.; Schmoll, B. K.; Sedgwick, K.; Seele, J.; Seidl, R.; Semenov, A. Yu.; Semenov, V.; Sen, A.; Seto, R.; Sett, P.; Sexton, A.; Sharma, D.; Shein, I.; Shevel, A.; Shibata, T.-A.; Shigaki, K.; Shim, H. H.; Shimomura, M.; Shoji, K.; Shukla, P.; Sickles, A.; Silva, C. L.; Silvermyr, D.; Silvestre, C.; Sim, K. S.; Singh, B. K.; Singh, C. P.; Singh, V.; Skutnik, S.; Slunečka, M.; Snowball, M.; Sodre, T.; Soldatov, A.; Soltz, R. A.; Sondheim, W. E.; Sorensen, S. P.; Sourikova, I. V.; Staley, F.; Stankus, P. W.; Stenlund, E.; Stepanov, M.; Ster, A.; Stoll, S. P.; Sugitate, T.; Suire, C.; Sukhanov, A.; Sumita, T.; Sun, J.; Sziklai, J.; Tabaru, T.; Takagi, S.; Takagui, E. M.; Takahara, A.; Taketani, A.; Tanabe, R.; Tanaka, Y.; Taneja, S.; Tanida, K.; Tannenbaum, M. J.; Tarafdar, S.; Taranenko, A.; Tarján, P.; Tennant, E.; Themann, H.; Thomas, D.; Thomas, T. L.; Tieulent, R.; Timilsina, A.; Todoroki, T.; Togawa, M.; Toia, A.; Tojo, J.; Tomášek, L.; Tomášek, M.; Tomita, Y.; Torii, H.; Towell, C. L.; Towell, R.; Towell, R. S.; Tram, V.-N.; Tserruya, I.; Tsuchimoto, Y.; Utsunomiya, K.; Vale, C.; Valle, H.; van Hecke, H. W.; Vazquez-Zambrano, E.; Veicht, A.; Velkovska, J.; Vértesi, R.; Vinogradov, A. A.; Virius, M.; Vossen, A.; Vrba, V.; Vznuzdaev, E.; Wagner, M.; Walker, D.; Wang, X. R.; Watanabe, D.; Watanabe, K.; Watanabe, Y.; Watanabe, Y. S.; Wei, F.; Wei, R.; Wessels, J.; White, A. S.; White, S. N.; Winter, D.; Woody, C. L.; Wright, R. M.; Wysocki, M.; Xia, B.; Xie, W.; Xue, L.; Yalcin, S.; Yamaguchi, Y. L.; Yamaura, K.; Yang, R.; Yanovich, A.; Yasin, Z.; Ying, J.; Yokkaichi, S.; Yoo, J. H.; Yoo, J. S.; Yoon, I.; You, Z.; Young, G. R.; Younus, I.; Yu, H.; Yushmanov, I. E.; Zajc, W. A.; Zaudtke, O.; Zelenski, A.; Zhang, C.; Zhou, S.; Zimamyi, J.; Zolin, L.; Zou, L.; Phenix Collaboration

2015-10-01

We present the first measurement of elliptic (v2) and triangular (v3) flow in high-multiplicity 3He +Au collisions at √{sN N }=200 GeV . Two-particle correlations, where the particles have a large separation in pseudorapidity, are compared in 3He +Au and in p +p collisions and indicate that collective effects dominate the second and third Fourier components for the correlations observed in the 3He +Au system. The collective behavior is quantified in terms of elliptic v2 and triangular v3 anisotropy coefficients measured with respect to their corresponding event planes. The v2 values are comparable to those previously measured in d +Au collisions at the same nucleon-nucleon center-of-mass energy. Comparisons with various theoretical predictions are made, including to models where the hot spots created by the impact of the three 3He nucleons on the Au nucleus expand hydrodynamically to generate the triangular flow. The agreement of these models with data may indicate the formation of low-viscosity quark-gluon plasma even in these small collision systems.

Triangular laser-induced submicron textures for functionalising stainless steel surfaces

NASA Astrophysics Data System (ADS)

Romano, Jean-Michel; Garcia-Giron, Antonio; Penchev, Pavel; Dimov, Stefan

2018-05-01

Processing technologies that engineer surfaces with sub-micron topographies are of a growing interest to a range of optical, hydrophobic and microbiological applications. One of the promising technologies for creating such topographies employs ultra-short laser pulses to produce laser-induced periodic surface structures (LIPSS) that often result in non-regular, quasi-periodic nanoripples and nanopillars. In this research near infrared ultra-short pulses of 310 fs with a circular polarisation was used to texture ferritic stainless steel workpieces. A single-step process was designed to generate low spatial frequency LIPSS (LSFL) over relatively large areas. Apart from highly regular and homogeneous parallel lines with approximately 900 nm periodicity, extraordinarily uniform triangular-LSFL in hexagonal arrangements was created. The generation of such LSFL was found to be highly repeatable but very sensitive to the used laser processing settings. Therefore, the sensitivity of triangular-LSFL formation to the used laser processing settings, i.e. pulse to pulse distance, pulse fluence and focal plane offsets, were investigated in regard to the resulting morphologies and functional properties, i.e. structural colors and super-hydrophobicity. Finally, the capability of this technology for producing uniform triangular-shaped LSFL on relatively large surface areas of stainless steel plates was studied.

Measurements of elliptic and triangular flow in high-multiplicity 3He+Au collisions at √s NN=200 GeV

DOE PAGES

Adare, A.

2015-09-28

We present the first measurement of elliptic (v 2) and triangular (v 3) flow in high-multiplicity 3He+Aucollisions at √s NN=200 GeV. Two-particle correlations, where the particles have a large separation in pseudorapidity, are compared in 3He+Au and in p+p collisions and indicate that collective effects dominate the second and third Fourier components for the correlations observed in the 3He+Ausystem. The collective behavior is quantified in terms of elliptic v 2 and triangular v 3 anisotropy coefficients measured with respect to their corresponding event planes. The v 2 values are comparable to those previously measured in d+Au collisions at the samemore » nucleon-nucleon center-of-mass energy. Comparisons with various theoretical predictions are made, including to models where the hot spots created by the impact of the three 3He nucleons on the Au nucleus expand hydrodynamically to generate the triangular flow. The agreement of these models with data may indicate the formation of low-viscosity quark-gluon plasma even in these small collision systems.« less

Evaluation of the sealing ability of gutta-percha and thermoplastic synthetic polymer-based systems along the root canals through the glucose penetration model.

PubMed

Kaya, B Ureyen; Kececi, Ayşe Diljin; Belli, S

2007-12-01

To compare the sealing ability of gutta-percha and thermoplastic synthetic polymer-based systems along the root canals using a recently introduced glucose penetration model. Premolars (n = 156) instrumented to an apical size of .06/40 were divided into 12 experimental and 2 control groups. The root canals were filled with either gutta-percha (groups 1-6) or Resilon (groups 7-12) core materials combined with AH Plus (groups 1, 4, 7, 0), Ketac Endo (groups 1, 5, 8, 11), or Epiphany (groups 2, 6, 9, 12), using cold lateral compaction (groups 1-3, 7-9) or System B with Obtura II (groups 4-6, 10-12). The leaked glucose concentration was measured spectrophotometrically at 1, 8, 15, 22, and 30 days. Percentage leaking of each group was also calculated. Data were recorded as mmol/L and statistically analyzed with Kruskal-Wallis and Mann-Whitney U tests (P = .05). Throughout the experimental period Resilon/Ketac-Endo/cold lateral compaction (group 8) showed the highest mean cumulative glucose penetration (mmol/L) (17.27 +/- 10.32), whereas Resilon/AH Plus/cold lateral compaction (group 7) had the least (3.36 +/- 4.65) (P < .05). At the 30(th) day, the least leaking percentage was observed in gutta-percha, Epiphany/cold lateral compaction (group 3). Glucose penetration was affected by the obturation technique in some groups. Ketac-Endo either with gutta-percha (group 2) or Resilon (group 8) indicated significantly less glucose penetration in warm technique, whereas gutta-percha/Epiphany (group 3) had significantly less glucose penetration in cold technique (P < .05). All material/technique combinations allowed glucose penetration. Gutta-percha/AH Plus combinations allowed similar patterns of glucose penetration to Resilon/Epiphany combinations.

Coagulation and ablation patterns of high-intensity focused ultrasound on a tissue-mimicking phantom and cadaveric skin.

PubMed

Kim, Hee-Jin; Kim, Han Gu; Zheng, Zhenlong; Park, Hyoun Jun; Yoon, Jeung Hyun; Oh, Wook; Lee, Cheol Woo; Cho, Sung Bin

2015-12-01

High-intensity focused ultrasound (HIFU) can be applied noninvasively to create focused zones of tissue coagulation on various skin layers. We performed a comparative study of HIFU, evaluating patterns of focused tissue coagulation and ablation upon application thereof. A tissue-mimicking (TM) phantom was prepared with bovine serum albumin and polyacrylamide hydrogel to evaluate the geometric patterns of HIFU-induced thermal injury zones (TIZs) for five different HIFU devices. Additionally, for each device, we investigated histologic patterns of HIFU-induced coagulation and ablation in serial sections of cadaveric skin of the face and neck. All HIFU devices generated remarkable TIZs in the TM phantom, with different geometric values of coagulation for each device. Most of the TIZs seemed to be separated into two or more tiny parts. In cadaveric skin, characteristic patterns of HIFU-induced ablation and coagulation were noted along the mid to lower dermis at the focal penetration depth of 3 mm and along subcutaneous fat to the superficial musculoaponeurotic system or the platysma muscle of the neck at 4.5 mm. Additionally, remarkable pre-focal areas of tissue coagulation were observed in the upper and mid dermis at the focal penetration depth of 3 mm and mid to lower dermis at 4.5 mm. For five HIFU devices, we outlined various patterns of HIFU-induced TIZ formation along pre-focal, focal, and post-focal areas of TM phantom and cadaveric skin of the face and neck.

Communication-avoiding symmetric-indefinite factorization

DOE PAGES

Ballard, Grey Malone; Becker, Dulcenia; Demmel, James; ...

2014-11-13

We describe and analyze a novel symmetric triangular factorization algorithm. The algorithm is essentially a block version of Aasen's triangular tridiagonalization. It factors a dense symmetric matrix A as the product A=PLTL TP T where P is a permutation matrix, L is lower triangular, and T is block tridiagonal and banded. The algorithm is the first symmetric-indefinite communication-avoiding factorization: it performs an asymptotically optimal amount of communication in a two-level memory hierarchy for almost any cache-line size. Adaptations of the algorithm to parallel computers are likely to be communication efficient as well; one such adaptation has been recently published. Asmore » a result, the current paper describes the algorithm, proves that it is numerically stable, and proves that it is communication optimal.« less

Effect of progressively increasing lithium conditioning on edge transport and stability in high triangularity NSTX H-modes

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

Maingi, R.; Canik, J. M.; Bell, R. E.

A sequence of H-mode discharges with increasing levels of pre-discharge lithium evaporation (‘dose’) was conducted in high triangularity and elongation boundary shape in NSTX. Energy confinement increased, and recycling decreased with increasing lithium dose, similar to a previous lithium dose scan in medium triangularity and elongation plasmas. Data-constrained SOLPS interpretive modeling quantified the edge transport change: the electron particle diffusivity decreased by 10-30x. The electron thermal diffusivity decreased by 4x just inside the top of the pedestal, but increased by up to 5x very near the separatrix. These results provide a baseline expectation for lithium benefits in NSTX-U, which ismore » optimized for a boundary shape similar to the one in this experiment.« less

Effect of progressively increasing lithium conditioning on edge transport and stability in high triangularity NSTX H-modes

DOE PAGES

Maingi, R.; Canik, J. M.; Bell, R. E.; ...

2016-07-19

A sequence of H-mode discharges with increasing levels of pre-discharge lithium evaporation (‘dose’) was conducted in high triangularity and elongation boundary shape in NSTX. Energy confinement increased, and recycling decreased with increasing lithium dose, similar to a previous lithium dose scan in medium triangularity and elongation plasmas. Data-constrained SOLPS interpretive modeling quantified the edge transport change: the electron particle diffusivity decreased by 10-30x. The electron thermal diffusivity decreased by 4x just inside the top of the pedestal, but increased by up to 5x very near the separatrix. These results provide a baseline expectation for lithium benefits in NSTX-U, which ismore » optimized for a boundary shape similar to the one in this experiment.« less

Mathematical models of the simplest fuzzy PI/PD controllers with skewed input and output fuzzy sets.

PubMed

Mohan, B M; Sinha, Arpita

2008-07-01

This paper unveils mathematical models for fuzzy PI/PD controllers which employ two skewed fuzzy sets for each of the two-input variables and three skewed fuzzy sets for the output variable. The basic constituents of these models are Gamma-type and L-type membership functions for each input, trapezoidal/triangular membership functions for output, intersection/algebraic product triangular norm, maximum/drastic sum triangular conorm, Mamdani minimum/Larsen product/drastic product inference method, and center of sums defuzzification method. The existing simplest fuzzy PI/PD controller structures derived via symmetrical fuzzy sets become special cases of the mathematical models revealed in this paper. Finally, a numerical example along with its simulation results are included to demonstrate the effectiveness of the simplest fuzzy PI controllers.

Self-Avoiding Walks over Adaptive Triangular Grids

NASA Technical Reports Server (NTRS)

Heber, Gerd; Biswas, Rupak; Gao, Guang R.; Saini, Subhash (Technical Monitor)

1998-01-01

In this paper, we present a new approach to constructing a "self-avoiding" walk through a triangular mesh. Unlike the popular approach of visiting mesh elements using space-filling curves which is based on a geometric embedding, our approach is combinatorial in the sense that it uses the mesh connectivity only. We present an algorithm for constructing a self-avoiding walk which can be applied to any unstructured triangular mesh. The complexity of the algorithm is O(n x log(n)), where n is the number of triangles in the mesh. We show that for hierarchical adaptive meshes, the algorithm can be easily parallelized by taking advantage of the regularity of the refinement rules. The proposed approach should be very useful in the run-time partitioning and load balancing of adaptive unstructured grids.

Communication-avoiding symmetric-indefinite factorization

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

Ballard, Grey Malone; Becker, Dulcenia; Demmel, James

We describe and analyze a novel symmetric triangular factorization algorithm. The algorithm is essentially a block version of Aasen's triangular tridiagonalization. It factors a dense symmetric matrix A as the product A=PLTL TP T where P is a permutation matrix, L is lower triangular, and T is block tridiagonal and banded. The algorithm is the first symmetric-indefinite communication-avoiding factorization: it performs an asymptotically optimal amount of communication in a two-level memory hierarchy for almost any cache-line size. Adaptations of the algorithm to parallel computers are likely to be communication efficient as well; one such adaptation has been recently published. Asmore » a result, the current paper describes the algorithm, proves that it is numerically stable, and proves that it is communication optimal.« less

The effect of intermediate clothing targets on shotgun ballistics.

PubMed

Cail, Kenneth; Klatt, Edward

2013-12-01

The ballistic properties of shotgun shells are complex because of multiple projectiles fired simultaneously that interact and spread out to affect their energy relayed to a human target. Intermediate targets such as clothing can affect penetration into tissues. We studied the effect of common clothing fabrics as intermediate targets on penetration of shotgun shell pellets, using ordnance gelatin to simulate soft tissue and thin cowhide to simulate skin. A standard 12-gauge shotgun with modified choke was used with no. 8 shot ammunition. We found that protection afforded by fabrics to reduce penetration of shotgun pellets into tissues was greater at increasing distance from the muzzle beyond 40 yd (36.6 m). The thicker denim and cotton fabrics provided slightly greater protection than polyester. This study demonstrates that clothing modifies the potential wound patterns to victims of shotgun injuries.

Analysis of the Origin of Atypical Scanning Laser Polarimetry Patterns by Polarization-Sensitive Optical Coherence Tomography

PubMed Central

Götzinger, Erich; Pircher, Michael; Baumann, Bernhard; Hirn, Cornelia; Vass, Clemens; Hitzenberger, Christoph K.

2010-01-01

Purpose To analyze the physical origin of atypical scanning laser polarimetry (SLP) patterns. To compare polarization-sensitive optical coherence tomography (PS-OCT) scans to SLP images. To present a method to obtain pseudo-SLP images by PS-OCT that are free of atypical artifacts. Methods Forty-one eyes of healthy subjects, subjects with suspected glaucoma, and patients with glaucoma were imaged by SLP (GDx VCC) and a prototype spectral domain PS-OCT system. The PS-OCT system acquires three-dimensional (3D) datasets of intensity, retardation, and optic axis orientation simultaneously within 3 seconds. B-scans of intensity and retardation and en face maps of retinal nerve fiber layer (RNFL) retardation were derived from the 3D PS-OCT datasets. Results were compared with those obtained by SLP. Results Twenty-two eyes showed atypical retardation patterns, and 19 eyes showed normal patterns. From the 22 atypical eyes, 15 showed atypical patterns in both imaging modalities, five were atypical only in SLP images, and two were atypical only in PS-OCT images. In most (15 of 22) atypical cases, an increased penetration of the probing beam into the birefringent sclera was identified as the source of atypical patterns. In such cases, the artifacts could be eliminated in PS-OCT images by depth segmentation and exclusion of scleral signals. Conclusions PS-OCT provides deeper insight into the contribution of different fundus layers to SLP images. Increased light penetration into the sclera can distort SLP retardation patterns of the RNFL. PMID:19036999

Spatial and Temporal Patterns of Biocide Action against Staphylococcus epidermidis Biofilms▿ ‡

PubMed Central

Davison, William M.; Pitts, Betsey; Stewart, Philip S.

2010-01-01

The dynamic antimicrobial action of chlorine, a quaternary ammonium compound, glutaraldehyde, and nisin within biofilm cell clusters of Staphylococcus epidermidis was investigated using time-lapse confocal scanning laser microscopy. The technique allowed for the simultaneous imaging of changes in biofilm structure and disruption of cellular membrane integrity through the loss of an unbound fluorophore loaded into bacterial cells prior to antimicrobial challenge. Each of the four antimicrobial agents produced distinct spatial and temporal patterns of fluorescence loss. The antimicrobial action of chlorine was localized around the periphery of biofilm cell clusters. Chlorine was the only antimicrobial agent that caused any biofilm removal. Treatment with the quaternary ammonium compound caused membrane permeabilization that started at the periphery of cell clusters, then migrated steadily inward. A secondary pattern superimposed on the penetration dynamic suggested a subpopulation of less-susceptible cells. These bacteria lost fluorescence much more slowly than the majority of the population. Nisin caused a rapid and uniform loss of green fluorescence from all parts of the biofilm without any removal of biofilm. Glutaraldehyde caused no biofilm removal and also no loss of membrane integrity. Measurements of biocide penetration and action time at the center of cell clusters yielded 46 min for 10 mg liter−1 chlorine, 21 min for 50 mg liter−1 chlorine, 25 min for the quaternary ammonium compound, and 4 min for nisin. These results underscore the distinction between biofilm removal and killing and reinforce the critical role of biocide reactivity in determining the rate of biofilm penetration. PMID:20457816

Diffusion patterns of new anti-diabetic drugs into hospitals in Taiwan: the case of Thiazolidinediones for diabetes

PubMed Central

2011-01-01

Background Diffusion of new drugs in the health care market affects patients' access to new treatment options and health care expenditures. We examined how a new drug class for diabetes mellitus, thiazolidinediones (TZDs), diffused in the health care market in Taiwan. Methods Assuming that monthly hospital prescriptions of TZDs could serve as a micro-market to perform drug penetration studies, we retrieved monthly TZD prescription data for 580 hospitals in Taiwan from Taiwan's National Health Insurance Research Database for the period between March 1, 2001 and December 31, 2005. Three diffusion parameters, time to adoption, speed of penetration (monthly growth on prescriptions), and peak penetration (maximum monthly prescription) were evaluated. Cox proportional hazards model and quantile regressions were estimated for analyses on the diffusion parameters. Results Prior hospital-level pharmaceutical prescription concentration significantly deterred the adoption of the new drug class (HR: 0.02, 95%CI = 0.01 to 0.04). Adoption of TZDs was slower in district hospitals (HR = 0.43, 95%CI = 0.24 to 0.75) than medical centers and faster in non-profit hospitals than public hospitals (HR = 1.79, 95%CI = 1.23 to 2.61). Quantile regression showed that penetration speed was associated with a hospital's prior anti-diabetic prescriptions (25%Q: 18.29; 50%Q: 25.57; 75%Q: 30.97). Higher peaks were found in hospitals that had adopted TZD early (25%Q: -40.33; 50%Q: -38.65; 75%Q: -32.29) and in hospitals in which the drugs penetrated more quickly (25%Q: 16.53; 50%Q: 24.91; 75%Q: 31.50). Conclusions Medical centers began to prescribe TZDs earlier, and they prescribed more TZDs at a faster pace. The TZD diffusion patterns varied among hospitals depending accreditation level, ownership type, and prescription volume of Anti-diabetic drugs. PMID:21281475

Mechanism of nanosecond laser drilling process of 4H-SiC for through substrate vias

NASA Astrophysics Data System (ADS)

Kim, Byunggi; Iida, Ryoichi; Doan, Duc Hong; Fushinobu, Kazuyoshi

2017-06-01

Role of optical parameters on nanosecond laser drilling of 4H-SiC was experimentally studied. Using ns pulsed Nd:YAG laser, parametric studies on effects of wavelength (1064 nm or 532 nm), beam profile (Gaussian or Bessel), and ambient condition (air or water) were conducted. The wavelengths which have large optical penetration depth were selected as wavefront has to propagate through materials to generate Bessel beam. The experimental results showed that carbonization of SiC surface accelerates thermal ablation of the materials with fluence under the lattice melting threshold. Especially, pattern of side lobes with small fluence was formed by irradiation of Bessel beam. The pattern disturbed penetration of wavefronts through materials. Implementation of water environment was not effective to suppress carbonization and had slight effect on improvement of drilling quality. For this reason, deep drilling with small entrance was not achieved using Bessel beam. Irradiation of 1064 nm Gaussian beam with large fluence led to formation of critical amount of re-solidified silicon due to the large optical penetration depth. Carbonization and silicon formation had a significant effect on unique fluence dependence of drilling depth. Absorption mechanism was studied as well to discuss effect of wavelength on processing characteristics.

Development of a skull/brain model for military wound ballistics studies.

PubMed

Carr, Debra; Lindstrom, Anne-Christine; Jareborg, Andreas; Champion, Stephen; Waddell, Neil; Miller, David; Teagle, Michael; Horsfall, Ian; Kieser, Jules

2015-05-01

Reports on penetrating ballistic head injuries in the literature are dominated by case studies of suicides; the penetrating ammunition usually being .22 rimfire or shotgun. The dominating cause of injuries in modern warfare is fragmentation and hence, this is the primary threat that military helmets protect the brain from. When helmets are perforated, this is usually by bullets. In combat, 20% of penetrating injuries occur to the head and its wounding accounts for 50% of combat deaths. A number of head simulants are described in the academic literature, in ballistic test methods for helmets (including measurement of behind helmet blunt trauma, BHBT) and in the 'open' and 'closed' government literature of several nations. The majority of these models are not anatomically correct and are not assessed with high-velocity rifle ammunition. In this article, an anatomically correct 'skull' (manufactured from polyurethane) and 'brain' (manufactured from 10%, by mass, gelatine) model for use in military wound ballistic studies is described. Filling the cranium completely with gelatine resulted in a similar 'skull' fracture pattern as an anatomically correct 'brain' combined with a representation of cerebrospinal fluid. In particular, posterior cranial fossa and occipital fractures and brain ejection were observed. This pattern of injury compared favourably to reported case studies of actual incidents in the literature.

Etched distributed Bragg reflectors as three-dimensional photonic crystals: photonic bands and density of states.

PubMed

Pavarini, E; Andreani, L C

2002-09-01

The photonic band dispersion and density of states (DOS) are calculated for the three-dimensional (3D) hexagonal structure corresponding to a distributed Bragg reflector patterned with a 2D triangular lattice of circular holes. Results for the Si/SiO(2) and GaAs/Al(x)Ga(1-x)As systems determine the optimal parameters for which a gap in the 2D plane occurs and overlaps the 1D gap of the multilayer. The DOS is considerably reduced in correspondence with the overlap of 2D and 1D gaps. Also, the local density of states (i.e., the DOS weighted with the squared electric field at a given point) has strong variations depending on the position. Both results imply substantial changes of spontaneous emission rates and patterns for a local emitter embedded in the structure and make this system attractive for the fabrication of a 3D photonic crystal with controlled radiative properties.

Conformal dip-coating of patterned surfaces for capillary die-to-substrate self-assembly

NASA Astrophysics Data System (ADS)

Mastrangeli, M.; Ruythooren, W.; Van Hoof, C.; Celis, J.-P.

2009-04-01

Capillarity-driven self-assembly of small chips onto planar target substrates is a promising alternative to robotic pick-and-place assembly. It critically relies on the selective deposition of thin fluid films on patterned binding sites, which is anyway normally non-conformal. We found that the addition of a thin wetting sidewall, surrounding the entire site perimeter, enables the conformal fluid coverage of arbitrarily shaped sites through dip-coating, significantly improves the reproducibility of the coating process and strongly reduces its sensitivity to surface defects. In this paper we support the feasibility and potential of this method by demonstrating the conformal dip-coating of square and triangular sites conditioned with combinations of different hydrophobic and hydrophilic surface chemistries. We present both experimental and simulative evidence of the advantages brought by the introduction of the wetting boundary on film coverage accuracy. Application of our surface preparation method to capillary self-assembly could result in higher precision in die-to-substrate registration and larger freedom in site shape design.

Geometric features of workspace and joint-space paths of 3D reaching movements.

PubMed

Klein Breteler, M D; Meulenbroek, R G; Gielen, S C

1998-11-01

The present study focuses on geometric features of workspace and joint-space paths of three-dimensional reaching movements. Twelve subjects repeatedly performed a three-segment, triangular-shaped movement pattern in an approximately 60 degrees tilted horizontal plane. Task variables elicited movement patterns that varied in position, rotational direction and speed. Trunk, arm, hand and finger-tip movements were recorded by means of a 3D motion-tracking system. Angular excursions of the shoulder and elbow joints were extracted from position data. Analyses of the shape of 3D workspace and joint-space paths focused on the extent to which the submovements were produced in a plane, and on the curvature of the central parts of the submovements. A systematic tendency to produce movements in a plane was found in addition to an increase of finger-tip path curvature with increasing speed. The findings are discussed in relation to the role of optimization principles in trajectory-formation models.

Structural and electronic transformation in low-angle twisted bilayer graphene

NASA Astrophysics Data System (ADS)

Gargiulo, Fernando; Yazyev, Oleg V.

2018-01-01

Experiments on bilayer graphene unveiled a fascinating realization of stacking disorder where triangular domains with well-defined Bernal stacking are delimited by a hexagonal network of strain solitons. Here we show by means of numerical simulations that this is a consequence of a structural transformation of the moiré pattern inherent to twisted bilayer graphene taking place at twist angles θ below a crossover angle θ\\star=1.2\\circ . The transformation is governed by the interplay between the interlayer van der Waals interaction and the in-plane strain field, and is revealed by a change in the functional form of the twist energy density. This transformation unveils an electronic regime characteristic of vanishing twist angles in which the charge density converges, though not uniformly, to that of ideal bilayer graphene with Bernal stacking. On the other hand, the stacking domain boundaries form a distinct charge density pattern that provides the STM signature of the hexagonal solitonic network.

New triangular and quadrilateral plate-bending finite elements

NASA Technical Reports Server (NTRS)

Narayanaswami, R.

1974-01-01

A nonconforming plate-bending finite element of triangular shape and associated quadrilateral elements are developed. The transverse displacement is approximated within the element by a quintic polynomial. The formulation takes into account the effects of transverse shear deformation. Results of the static and dynamic analysis of a square plate, with edges simply supported or clamped, are compared with exact solutions. Good accuracy is obtained in all calculations.

Tower Temperature and Humidity Sensors (TWR) Handbook

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

Cook, DR

2010-02-01

Three tall towers are installed at the Atmospheric Radiation Measurement (ARM) Climate Research Facility: a 60-meter triangular tower at the Southern Great Plains (SGP) Central Facility (CF), a 21-meter walkup scaffolding tower at the SGP Okmulgee forest site (E21), and a 40-meter triangular tower at the North Slope of Alaska (NSA) Barrow site. The towers are used for meteorological, radiological, and other measurements.

A Step-Wise Approach to Elicit Triangular Distributions

NASA Technical Reports Server (NTRS)

Greenberg, Marc W.

2013-01-01

Adapt/combine known methods to demonstrate an expert judgment elicitation process that: 1.Models expert's inputs as a triangular distribution, 2.Incorporates techniques to account for expert bias and 3.Is structured in a way to help justify expert's inputs. This paper will show one way of "extracting" expert opinion for estimating purposes. Nevertheless, as with most subjective methods, there are many ways to do this.

A Feasibility Study of Expanding the F404 Aircraft Engine Repair Capability at the Aircraft Intermediate Maintenance Department

DTIC Science & Technology

1993-06-01

1 A. OBJECTIVES ............. .... .................. 1 B. HISTORY ................... .................... 2 C...utilization, and any additional manpower requirements at the "selected" AIMD’s. B. HISTORY Until late 1991 both NADEP JAX and NADEP North Island (NORIS...TRIANGULAR OR ALL LOG NORMAL DISTRIBUTIONS FOR SERVICE TIMES AT AIND CECIL FIELD maintenance/ Triangular Log Normal MAZDA Difference Differe•ce Supply

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

Peche, Roberto, E-mail: roberto.peche@ehu.es; Rodriguez, Esther, E-mail: esther.rodriguez@ehu.e

This study shows the practical application of the EIA method based on fuzzy logic proposed by the authors (Peche and Rodriguez, 2009) to a simplified case of study-the activity of a petrol station throughout its exploitation. The intensity (p{sub 1}), the extent (p{sub 2}) and the persistence (p{sub 3}) were the properties selected to describe the impacts and their respective assessment functions v-bar{sub i}=f(p-bar{sub i}) were determined. The main actions (A) and potentially affected environmental factors (F) were selected. Every impact was identified by a pair A-F and the values of the three impact properties were estimated for each ofmore » them by means of triangular fuzzy numbers. Subsequently, the fuzzy estimation of every impact was carried out, the estimation of the impact A{sub 1}-F{sub 2} (V-bar{sub 1}) being explained in detail. Every impact was simultaneously represented by its corresponding generalised confidence interval and membership function. Since the membership functions of all impacts were similar to triangular fuzzy numbers, a triangular approach (TA) was used to describe every impact. A triangular approach coefficient (TAC) was introduced to quantify the similarity of each fuzzy number and its corresponding triangular approach, where TAC (V-bar) element of (0, 1] and TAC being 1 when the fuzzy number is triangular. The TACs-ranging from 0.96 to 0.99-proved that TAs were valid in all cases. Next, the total positive and negative impacts-TV-bar{sup +} and TV-bar{sup -} were calculated and later, the fuzzy value of the total environmental impact TV-bar was determined from them. Finally, the defuzzification of TV-bar led to the punctual impact estimator TV{sup (1)} = -88.50 and its corresponding uncertainty interval [{delta}{sub l}(TV-bar),{delta}{sub r}(TV-bar)]=[6.52,6.96], which represent the total value of the EI. In conclusion, the EIA method enabled the integration of heterogeneous impacts, which exerted influence on environmental factors of a very diverse nature in very different ways, into a global impact indicator.« less

Cranial injury caused by penetrating non-missile foreign body: an autopsy case.

PubMed

Eren, B; Türkmen, N; Toprak Ergönen, A; Gündogmus, U N

2012-10-01

Presented case was 32-year-old male marble worker, who underwent industrial accident at workplace. On gross physical examination; on forehead region round skin wound in 0.9 cm diameter was detected, radiological examination showed the image of metallic object. in the skull cavity. Brain dissection showed obvious brain injury, haemorrahge explaining the pattern of injury caused by the metallic bodys path, from left frontal lobe to the left cerebellar hemisphere was identified. We presented rare case of penetrating injury of the cranial region caused by non-missile foreign body. cranial injury - non-missile foreign body - autopsy.

Epidemiology and outcome of penetrating injuries in a Western European urban region.

PubMed

Störmann, P; Gartner, K; Wyen, H; Lustenberger, T; Marzi, I; Wutzler, S

2016-12-01

Severe life-threatening injuries in Western Europe are mostly caused by blunt trauma. However, penetrating trauma might be more common in urban regions, but their characteristics have not been fully elucidated. Retrospective analysis of data from patients admitted to our urban university level I trauma center between 2008 and 2013 with suspicion of severe multiple injuries. Collection of data was performed prospectively using a PC-supported online documentation program including epidemiological, clinical and outcome parameters. Out of 2095 trauma room patients admitted over the 6-year time period 194 (9.3 %) suffered from penetrating trauma. The mean Injury Severity Score (ISS) was 12.3 ± 14.1 points. In 62.4 % (n = 121) the penetrating injuries were caused by interpersonal violence or attempted suicide, 98 of these by stabbing and 23 by firearms. We observed a widespread injury pattern where mainly head, thorax and abdomen were afflicted. Subgroup analysis for self-inflicted injuries showed higher ISS (19.8 ± 21.8 points) than for blunt trauma (15.5 ± 14.6 points). In 82.5 % of all penetrating trauma a surgical treatment was performed, 43.8 % of the patients received intensive care unit treatment with mean duration of 7.4 ± 9.3 days. Immediate emergency surgical treatment had to be performed in 8.0 vs. 2.3 % in blunt trauma (p < 0.001). Infectious complications of the penetrating wounds were observed in 7.8 %. Specific characteristics of penetrating trauma in urban regions can be identified. Compared to nationwide data, penetrating trauma was more frequent in our collective (9.3 vs. 5.0 %), which may be due to higher crime rates in urban areas. Especially, self-inflicted penetrating trauma often results in most severe injuries.

Effect of Electrothermal Treatment on Nerve Tissue Within the Triangular Fibrocartilage Complex, Scapholunate, and Lunotriquetral Interosseous Ligaments.

PubMed

Pirolo, Joseph M; Le, Wei; Yao, Jeffrey

2016-05-01

To evaluate the effect of thermal treatment on neural tissue in the triangular fibrocartilage complex (TFCC), scapholunate interosseous ligament (SLIL), and lunotriquetral interosseous ligament (LTIL). The intact TFCC, SLIL, and LTIL were harvested from cadaveric specimens and treated with a radiofrequency probe as would be performed intraoperatively. Slides were stained using a triple-stain technique for neurotrophin receptor p75, pan-neuronal marker protein gene product 9.5 (PGP 9.5), and 4',6-diamidino-2-phenylindole for neural identification. Five TFCC, 5 SLIL, and 4 LTIL specimens were imaged with fluorescence microscopy. Imaging software was used to measure fluorescence signals and compare thermally treated areas with adjacent untreated areas. A paired t test was used to compare treated versus untreated areas. P < .05 was considered significant. For the TFCC, a mean of 94.9% ± 2.7% of PGP 9.5-positive neural tissue was ablated within a mean area of 11.7 ± 2.5 mm(2) (P = .02). For the SLIL treated from the radiocarpal surface, 97.4% ± 1.0% was ablated to a mean depth of 2.4 ± 0.3 mm from the surface and a mean horizontal spread of 3.4 ± 0.5 mm (P = .01). For the LTIL, 96.0% ± 1.5% was ablated to a mean depth of 1.7 ± 0.7 mm and a mean horizontal spread of 2.6 ± 1.0 mm (P = .02). Differences in the presence of neural tissue between treated areas and adjacent untreated areas were statistically significant for all specimens. Our study confirms elimination of neuronal markers after thermal treatment of the TFCC, SLIL, and LTIL in cadaveric specimens. This effect penetrates below the surface to innervated collagen tissue that is left structurally intact after treatment. Electrothermal treatment as commonly performed to treat symptomatic SLIL, LTIL, and TFCC tears eliminates neuronal tissue in treated areas and may function to relieve pain through a denervation effect. Copyright © 2016 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Distribution and magnitude of type I error of model-based multipoint lod scores: implications for multipoint mod scores.

PubMed

Xing, Chao; Elston, Robert C

2006-07-01

The multipoint lod score and mod score methods have been advocated for their superior power in detecting linkage. However, little has been done to determine the distribution of multipoint lod scores or to examine the properties of mod scores. In this paper we study the distribution of multipoint lod scores both analytically and by simulation. We also study by simulation the distribution of maximum multipoint lod scores when maximized over different penetrance models. The multipoint lod score is approximately normally distributed with mean and variance that depend on marker informativity, marker density, specified genetic model, number of pedigrees, pedigree structure, and pattern of affection status. When the multipoint lod scores are maximized over a set of assumed penetrances models, an excess of false positive indications of linkage appear under dominant analysis models with low penetrances and under recessive analysis models with high penetrances. Therefore, caution should be taken in interpreting results when employing multipoint lod score and mod score approaches, in particular when inferring the level of linkage significance and the mode of inheritance of a trait.

Surface preparation effects on GTA (gas tungsten arc) weld penetration in JBK-75 stainless steel

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

Campbell, R.D.; Heiple, C.R.; Sturgill, P.L.

1989-01-01

The results of a study are reported here on the effects of surface preparation on the shape of GTA welds on JBK-75, an austenitic precipitation hardenable stainless steel similar to A286. Minor changes in surface (weld groove) preparation produced substantial changes in the penetration characteristics and welding behavior of this alloy. Increased and more consistent weld penetration (higher d/w ratios) along with improved arc stability and less arc wander result from wire brushing and other abrasive surface preparations, although chemical and machining methods did not produce any improvement in penetration. Abrasive treatments roughen the surface, increase the surface area, andmore » increase the surface oxide thickness. The increased weld d/w ratio is attributed to oxygen added to the weld pool from the surface oxide on the base metal. The added oxygen alters the surface-tension driven fluid flow pattern in the weld pool. Similar results were observed with changes in filler wire surface oxide thickness, caused by changes in wire production conditions. 15 refs., 14 figs., 4 tabs.« less

A Systematic Review of Outcomes after Arthroscopic Débridement for Triangular Fibrocartilage Complex Tear.

PubMed

Saito, Taichi; Malay, Sunitha; Chung, Kevin C

2017-11-01

Evidence regarding the effectiveness of arthroscopic débridement for a triangular fibrocartilage complex tear is uncertain. The purpose of this study was to conduct a systematic review of outcomes to evaluate the effectiveness of débridement for triangular fibrocartilage complex tears. The authors searched all available literature in the PubMed, Embase, and MEDLINE (Ovid) databases for articles reporting on triangular fibrocartilage complex tear débridement. Data collection included arc of motion, grip strength, patient-reported outcomes, and complications. A total of 1723 unique studies were identified, of which 18 studies met the authors' criteria. The mean before and after arc of wrist extension/flexion motion values were 120 and 146 degrees (six studies). The mean before and after grip strength values were 65 percent and 91 percent of the contralateral side (10 studies). Disabilities of the Arm, Shoulder, and Hand scores (six studies) and pain visual analogue scale scores (seven studies) improved from 39 to 18, and from 7 to 3, respectively. The mean pain visual analogue scale score after débridement was 1.9 in the ulnar-positive group and 2.4 in the ulnar-neutral and ulnar-negative groups. Eighty-seven percent of patients returned to their original work. Patients reported reduced pain and improved functional and patient-reported outcomes after débridement of triangular fibrocartilage complex tears. Most patients after débridement returned to previous work, with few complications. Although some of these cases may require secondary procedures, simple débridement can be performed with suitable satisfactory outcomes for cases with any type of ulnar variance.

Gender differences in the form of maxillary central incisors analyzed using AutoCAD software.

PubMed

Brunetto, Juliana; Becker, Mirian Marly; Volpato, Claudia A Maziero

2011-08-01

Female teeth are considered more rounded and male teeth more quadrangular. Although lacking in scientific support, this theory helps in selecting the mold of artificial teeth for dentures. Parameters that are more reliable are sought to determine gender differences in tooth form. The purpose of this study was to assess possible differences between genders in terms of tooth form: oval, triangular, or quadrangular. The sample comprised 433 subjects with a mean age of 15 years selected from a population of Brazilian high school students. The maxillary right central incisor (MCI) of each subject was photographed. The images were adjusted to standardize the long axis of the tooth in the vertical position. The AutoCAD computer program was used to analyze graphically the geometric form of the tooth. According to analysis results, form was classified as oval, triangular, or quadrangular. Intraexaminer consistency was analyzed by using linear correlation coefficient and Bland Altman analysis. The relationship between gender and tooth form was analyzed by chi-square and linear regression (α=.05). In women, the form was 57.73% (n=127) oval, 23.54% (n=52) triangular, and 18.64% (n=41) quadrangular; while in men, the form was 54.93% (n=117) oval, 36.15% (n=77) triangular, and 8.92% (n=19) quadrangular (P<.001). The oval form was the most prevalent in both genders. However, the triangular form was more common in men than in women, and the quadrangular form more frequent in women than in men. Copyright © 2011 The Editorial Council of the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.

Cause and Cure-Deterioration in Accuracy of CFD Simulations with Use of High-Aspect-Ratio Triangular/Tetrahedral Grids

NASA Technical Reports Server (NTRS)

Chang, Sin-Chung; Chang, Chau-Lyan; Venkatachari, Balaji

2017-01-01

In the multi-dimensional space-time conservation element and solution element16 (CESE) method, triangles and tetrahedral mesh elements turn out to be the most natural building blocks for 2D and 3D spatial grids, respectively. As such, the CESE method is naturally compatible with the simplest 2D and 3D unstructured grids and thus can be easily applied to solve problems with complex geometries. However, because (a) accurate solution of a high-Reynolds number flow field near a solid wall requires that the grid intervals along the direction normal to the wall be much finer than those in a direction parallel to the wall and, as such, the use of grid cells with extremely high aspect ratio (103 to 106) may become mandatory, and (b) unlike quadrilateral hexahedral grids, it is well-known that accuracy of gradient computations involving triangular tetrahedral grids tends to deteriorate rapidly as cell aspect ratio increases. As a result, the use of triangular tetrahedral grid cells near a solid wall has long been deemed impractical by CFD researchers. In view of (a) the critical role played by triangular tetrahedral grids in the CESE development, and (b) the importance of accurate resolution of high-Reynolds number flow field near a solid wall, as will be presented in the main paper, a comprehensive and rigorous mathematical framework that clearly identifies the reasons behind the accuracy deterioration as described above has been developed for the 2D case involving triangular cells. By avoiding the pitfalls identified by the 2D framework, and its 3D extension, it has been shown numerically.

Pressure drop reduction and heat transfer deterioration of slush nitrogen in triangular and circular pipe flows

NASA Astrophysics Data System (ADS)

Ohira, Katsuhide; Kurose, Kizuku; Okuyama, Jun; Saito, Yutaro; Takahashi, Koichi

2017-01-01

Slush fluids such as slush hydrogen and slush nitrogen are characterized by superior properties as functional thermal fluids due to their density and heat of fusion. In addition to allowing efficient hydrogen transport and storage, slush hydrogen can serve as a refrigerant for high-temperature superconducting (HTS) equipment using MgB2, with the potential for synergistic effects. In this study, pressure drop reduction and heat transfer deterioration experiments were performed on slush nitrogen flowing in a horizontal triangular pipe with sides of 20 mm under the conditions of three different cross-sectional orientations. Experimental conditions consisted of flow velocity (0.3-4.2 m/s), solid fraction (0-25 wt.%), and heat flux (0, 10, and 20 kW/m2). Pressure drop reduction became apparent at flow velocities exceeding about 1.3-1.8 m/s, representing a maximum amount of reduction of 16-19% in comparison with liquid nitrogen, regardless of heating. Heat transfer deterioration was seen at flow velocities of over 1.2-1.8 m/s, for a maximum amount of deterioration of 13-16%. The authors of the current study compared the results for pressure drop reduction and heat transfer deterioration in triangular pipe with those obtained previously for circular and square pipes, clarifying differences in flow and heat transfer properties. Also, a correlation equation was obtained between the slush Reynolds number and the pipe friction factor, which is important in the estimation of pressure drop in unheated triangular pipe. Furthermore, a second correlation equation was derived between the modified slush Reynolds number and the pipe friction factor, enabling the integrated prediction of pressure drop in both unheated triangular and circular pipes.

Helioseismology.

ERIC Educational Resources Information Center

Leibacher, John W.; And Others

1985-01-01

Helioseismology (similar to geophysicists' study of seismic waves) makes it possible to penetrate the sun's opaque brilliance by measuring surface oscillations. Their pattern and period hold clues to temperature, structure, composition, and dynamics of the sun's interior. Scientists have used data to build models (evolved mathematically) to…

Optimal charging scheduler for electric vehicles on the Florida turnpike : final research project report.

DOT National Transportation Integrated Search

2017-06-01

This project developed a methodology to simulate and analyze roadway traffic patterns : and expected penetration and timing of electric vehicles (EVs) with application directed : toward the requirements for electric vehicle supply equipment (EVSE) si...

Multiorbital kinetic effects on charge ordering of frustrated electrons on the triangular lattice

NASA Astrophysics Data System (ADS)

Février, C.; Fratini, S.; Ralko, A.

2015-06-01

The role of the multiorbital effects on the emergence of frustrated electronic orders on the triangular lattice at half filling is investigated through an extended spinless fermion Hubbard model. By using two complementary approaches, unrestricted Hartree-Fock and exact diagonalizations, we unravel a very rich phase diagram controlled by the strength of both local and off-site Coulomb interactions and by the interorbital hopping anisotropy ratio t'/t . Three robust unconventional electronic phases, a pinball liquid, an inverse pinball liquid, and a large-unit-cell √{12 }×√{12 } droplet phase, are found to be generic in the triangular geometry, being controlled by the band structure parameters. The latter are also stabilized in the isotropic limit of our microscopic model, which recovers the standard SU(2) spinful extended single-band Hubbard model.

A New High-Order Spectral Difference Method for Simulating Viscous Flows on Unstructured Grids with Mixed Elements

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

Li, Mao; Qiu, Zihua; Liang, Chunlei

In the present study, a new spectral difference (SD) method is developed for viscous flows on meshes with a mixture of triangular and quadrilateral elements. The standard SD method for triangular elements, which employs Lagrangian interpolating functions for fluxes, is not stable when the designed accuracy of spatial discretization is third-order or higher. Unlike the standard SD method, the method examined here uses vector interpolating functions in the Raviart-Thomas (RT) spaces to construct continuous flux functions on reference elements. Studies have been performed for 2D wave equation and Euler equa- tions. Our present results demonstrated that the SDRT method ismore » stable and high-order accurate for a number of test problems by using triangular-, quadrilateral-, and mixed- element meshes.« less

Stability of triangular lagrangian points in elliptical restricted three body problem under the radiating binary systems

NASA Astrophysics Data System (ADS)

Narayan, A.; Singh, Nutan

2014-10-01

This paper studies the stability of Triangular Lagrangian points in the model of elliptical restricted three body problem, under the assumption that both the primaries are radiating. The model proposed is applicable to the well known binary systems Achird, Luyten, αCen AB, Kruger-60, Xi-Bootis. Conditional stability of the motion around the triangular points exists for 0≤ μ≤ μ ∗, where μ is the mass ratio. The method of averaging due to Grebenikov has been exploited throughout the analysis of stability of the system. The critical mass ratio depends on the combined effects of radiation of both the primaries and eccentricity of this orbit. It is found by adopting the simulation technique that the range of stability decreases as the radiation pressure parameter increases.

Surface enhanced Raman scattering, antibacterial and antifungal active triangular gold nanoparticles

NASA Astrophysics Data System (ADS)

Smitha, S. L.; Gopchandran, K. G.

2013-02-01

Shape controlled syntheses of gold nanoparticles have attracted a great deal of attention as their optical, electronic, magnetic and biological properties are strongly dependent on the size and shape of the particles. Here is a report on the surface enhanced Raman scattering (SERS) activity of Cinnamomum zeylanicum leaf broth reduced gold nanoparticles consisting of triangular and spherical like particles, using 2-aminothiophenol (2-ATP) and crystal violet (CV) as probe molecules. Nanoparticles prepared with a minimum leaf broth concentration, having a greater number of triangular like particles exhibit a SERS activity of the order of 107. The synthesized nanoparticles exhibit efficient antibacterial activity against the tested gram negative bacterium Escherichia coli and gram positive bacterium Staphylococcus aureus. Investigations on the antifungal activity of the synthesized nanoparticles against Aspergillus niger and Fusarium oxysporum positive is also discussed.

Reconsideration of data and correlations for plate finned-tube heat exchangers

NASA Astrophysics Data System (ADS)

Otović, Milena; Mihailović, Miloš; Genić, Srbislav; Jaćimović, Branislav; Milovančević, Uroš; Marković, Saša

2018-04-01

This paper deals with heat exchangers having plain finned tubes in staggered (triangular) pattern. The objective of this paper is to provide the heat transfer and friction factor correlation which can be used in engineering practice. For this purpose, the experimental data of several (most cited) authors who deal with this type of heat exchangers are used. The new correlations are established to predict the air-side heat transfer coefficient and friction factor as a function of the Reynolds number and geometric variables of the heat exchanger - tube diameter, tube pitch, fin spacing, tube rows, etc. In those correlations the characteristic dimension in Reynolds number is calculated by using the new parameter - volumetric porosity. Also, there are given the errors of those correlations.

Influence of substrate micropatterning on biofilm growth

NASA Astrophysics Data System (ADS)

Koehler, Stephan; Li, Yiwei; Liu, Bi-Feng Liu; Weitz, David

2015-11-01

We culture triple reporter Bacillus Subtilis biofilm on micropatterned agar substrates. We track the biofilm development in terms of size, thickness, shape, and phenotype expression. For a tiling composed of elevated rectangles, we observe the biofilm develops an oval shape or triangular shape depending on the rectangle's aspect ratio and orientation. The motile cells are primarily located in the valleys between the rectangles and the matrix producing cells are mostly located on the rectangles. Wrinkles form at the edges of the elevated surfaces, and upon merging form channels centered on the elevated surface. After a few days, the spore-forming cells appear at the periphery. Since biofilms in nature grow on irregular surfaces, our work may provide insight into the complex patterns observed.

Nodal domains of a non-separable problem—the right-angled isosceles triangle

NASA Astrophysics Data System (ADS)

Aronovitch, Amit; Band, Ram; Fajman, David; Gnutzmann, Sven

2012-03-01

We study the nodal set of eigenfunctions of the Laplace operator on the right-angled isosceles triangle. A local analysis of the nodal pattern provides an algorithm for computing the number νn of nodal domains for any eigenfunction. In addition, an exact recursive formula for the number of nodal domains is found to reproduce all existing data. Eventually, we use the recursion formula to analyse a large sequence of nodal counts statistically. Our analysis shows that the distribution of nodal counts for this triangular shape has a much richer structure than the known cases of regular separable shapes or completely irregular shapes. Furthermore, we demonstrate that the nodal count sequence contains information about the periodic orbits of the corresponding classical ray dynamics.

A reflection polarizations zoom metasurfaces

NASA Astrophysics Data System (ADS)

Yang, Fulong; Wang, Xiaoyan

2017-02-01

Based on generalized Snell's law, we propose a dual-polarity zoom metasurfaces operating electromagnetic wave in the reflection geometry. The metasurfaces is constructed by two identical ultrathin metal-backed dielectric slabs with metallic Jerusalem cross patterns on the other sides to form a triangular region. The normally incident waves are totally reflected, but the reflection phases of both x- and y-polarized waves are controlled independently. According to the classical theory of optical imaging, the reflection electromagnetic wave phases were obtained in the different polarizations and focus. Each subwavelength units size were determined with the reflection coefficient of the basic unit, the polarizations zoom metasurfaces was designed in the way. The full-wave simulations are in good agreement with theoretical analysis in microwave lengths.

Immunohistochemical Mapping of Sensory Nerve Endings in the Human Triangular Fibrocartilage Complex.

PubMed

Rein, Susanne; Semisch, Manuel; Garcia-Elias, Marc; Lluch, Alex; Zwipp, Hans; Hagert, Elisabet

2015-10-01

The triangular fibrocartilage complex is the main stabilizer of the distal radioulnar joint. While static joint stability is constituted by osseous and ligamentous integrity, the dynamic aspects of joint stability chiefly concern proprioceptive control of the compressive and directional muscular forces acting on the joint. Therefore, an investigation of the pattern and types of sensory nerve endings gives more insight in dynamic distal radioulnar joint stability. We aimed to (1) analyze the general distribution of sensory nerve endings and blood vessels; (2) examine interstructural distribution of sensory nerve endings and blood vessels; (3) compare the number and types of mechanoreceptors in each part; and (4) analyze intrastructural distribution of nerve endings at different tissue depth. The subsheath of the extensor carpi ulnaris tendon sheath, the ulnocarpal meniscoid, the articular disc, the dorsal and volar radioulnar ligaments, and the ulnolunate and ulnotriquetral ligaments were dissected from 11 human cadaver wrists. Sensory nerve endings were counted in five levels per specimen as total cell amount/cm(2) after staining with low-affinity neurotrophin receptor p75, protein gene product 9.5, and S-100 protein and thereafter classified according to Freeman and Wyke. All types of sensory corpuscles were found in the various structures of the triangular fibrocartilage complex with the exception of the ulnolunate ligament, which contained only Golgi-like endings, free nerve endings, and unclassifiable corpuscles. The articular disc had only free nerve endings. Furthermore, free nerve endings were the predominant sensory nerve ending (median, 72.6/cm(2); range, 0-469.4/cm(2)) and more prevalent than all other types of mechanoreceptors: Ruffini (median, 0; range, 0-5.6/cm(2); difference of medians, 72.6; p < 0.001), Pacini (median, 0; range, 0-3.8/cm(2); difference of medians, 72.6; p < 0.001), Golgi-like (median, 0; range, 0-2.1/cm(2); difference of medians, 72.6; p < 0.001), and unclassifiable corpuscles (median, 0; range, 0-2.5/cm(2); difference of medians, 72.6; p < 0.001). The articular disc contained fewer free nerve endings (median, 1.8; range, 0-17.8/cm(2)) and fewer blood vessels (median, 29.8; range, 0-112.2/cm(2); difference of medians: 255.9) than all other structures of the triangular fibrocartilage complex (p ≤ 0.001, respectively) except the ulnolunate ligament. More blood vessels were seen in the volar radioulnar ligament (median, 363.62; range, 117.8-871.8/cm(2)) compared with the ulnolunate ligament (median, 107.7; range, 15.9-410.3/cm(2); difference of medians: 255.91; p = 0.002) and the dorsal radioulnar ligament (median, 116.2; range, 53.9-185.1/cm(2); difference of medians: 247.47; p = 0.001). Free nerve endings were obtained in each structure more often than all other types of sensory nerve endings (p < 0.001, respectively). The intrastructural analysis revealed no differences in mechanoreceptor distribution in all investigated specimens with the numbers available, showing a homogenous distribution of proprioceptive qualities in all seven parts of the triangular fibrocartilage complex. Nociception has a primary proprioceptive role in the neuromuscular stability of the distal radioulnar joint. The articular disc and ulnolunate ligament rarely are innervated, which implies mainly mechanical functions, whereas all other structures have pronounced proprioceptive qualities, prerequisite for dynamic joint stability. Lesions of the volar and dorsal radioulnar ligaments have immense consequences not only for mechanical but also for dynamic stability of the distal radioulnar joint, and surgical reconstruction in instances of radioulnar ligament injury is important.

Numerical simulation of a flow past a triangular sail-type blade of a wind generator using the ANSYS FLUENT software package

NASA Astrophysics Data System (ADS)

Kusaiynov, K.; Tanasheva, N. K.; Min'kov, L. L.; Nusupbekov, B. R.; Stepanova, Yu. O.; Rozhkova, A. V.

2016-02-01

An air flow past a single triangular sail-type blade of a wind turbine is analyzed by numerical simulation for low velocities of the incoming flow. The results of numerical simulation indicate a monotonic increase in the drag force and the lift force as functions of the incoming flow; empirical dependences of these quantities are obtained.

Radar Cross Section Prediction for Coated Perfect Conductors with Arbitrary Geometries.

DTIC Science & Technology

1986-01-01

equivalent electric and magnetic surface currents as the desired unknowns. Triangular patch modelling is ap- plied to the boundary surfaces. The method of...matrix inversion for the unknown surface current coefficients. Huygens’ principle is again applied to calculate the scattered electric field produced...differential equations with the equivalent electric and magnetic surface currents as the desired unknowns. Triangular patch modelling is ap- plied to the

Effects on the Distal Radioulnar Joint of Ablation of Triangular Fibrocartilage Complex Tears With Radiofrequency Energy.

PubMed

Huber, Michaela; Loibl, Markus; Eder, Christoph; Kujat, Richard; Nerlich, Michael; Gehmert, Sebastian

2016-11-01

This cadaver study investigated the temperature profile in the wrist joint and distal radioulnar joint (DRUJ) during radiofrequency energy (RFE) application for triangular fibrocartilage complex resection. An arthroscopic partial resection of the triangular fibrocartilage complex using monopolar and bipolar RFE was simulated in 14 cadaver limbs. The temperature was recorded simultaneously in the DRUJ and at 6 other anatomic locations of the wrist during RFE application. The mean temperature in the DRUJ was 43.3 ± 8.2°C for the bipolar system in the ablation mode (60 W) and 30.4 ± 3.4°C for the monopolar system in the cut mode (20 W) after 30 seconds. The highest measured temperature in the DRUJ was 54.3°C for the bipolar system and 68.1°C for the monopolar system. The application of RFE for debridement or resection of the triangular fibrocartilage complex in a clinical setting can induce peak temperatures that might cause damage to the cartilage of the DRUJ. Bipolar systems produce higher mean temperatures than monopolar devices. RFE application increases the mean temperature in the DRUJ after 30 seconds to a level that may jeopardize cartilage tissue. Copyright © 2016 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

Comparison between open and arthroscopic-assisted foveal triangular fibrocartilage complex repair for post-traumatic distal radio-ulnar joint instability.

PubMed

Luchetti, R; Atzei, A; Cozzolino, R; Fairplay, T; Badur, N

2014-10-01

The aim of this study was to assess the objective and subjective functional outcomes after foveal reattachment of proximal or complete ulnar-sided triangular fibrocartilage complex lesions by two surgical procedures: an open technique or an arthroscopically assisted repair. The study was done prospectively on 49 wrists affected by post-traumatic distal radio-ulnar joint instability. Twenty-four patients were treated with the open technique (Group 1) and 25 by the arthroscopically assisted technique (Group 2). Magnetic resonance imaging demonstrated a clear foveal detachment of the triangular fibrocartilage complex in 67% of the cases. Arthroscopy showed a positive ulnar-sided detachment of the triangular fibrocartilage complex (positive hook test) in all cases. Distal radio-ulnar joint stability was obtained in all but five patients at a mean follow-up of 6 months. Both groups had improvement of all parameters with significant differences in wrist pain scores, Mayo wrist score, Disability of the Arm, Shoulder and Hand questionnaire and Patient-Rated Wrist/Hand Evaluation questionnaire scores. There were no significant post-operative differences between the two groups in the outcome parameters except for the Disability of the Arm Shoulder and Hand questionnaire score, which was significantly better in Group 2 (p < 0.001). © The Author(s) 2013.

An Evaluation of Fractal Surface Measurement Methods for Characterizing Landscape Complexity from Remote-Sensing Imagery

NASA Technical Reports Server (NTRS)

Lam, Nina Siu-Ngan; Qiu, Hong-Lie; Quattrochi, Dale A.; Emerson, Charles W.; Arnold, James E. (Technical Monitor)

2001-01-01

The rapid increase in digital data volumes from new and existing sensors necessitates the need for efficient analytical tools for extracting information. We developed an integrated software package called ICAMS (Image Characterization and Modeling System) to provide specialized spatial analytical functions for interpreting remote sensing data. This paper evaluates the three fractal dimension measurement methods: isarithm, variogram, and triangular prism, along with the spatial autocorrelation measurement methods Moran's I and Geary's C, that have been implemented in ICAMS. A modified triangular prism method was proposed and implemented. Results from analyzing 25 simulated surfaces having known fractal dimensions show that both the isarithm and triangular prism methods can accurately measure a range of fractal surfaces. The triangular prism method is most accurate at estimating the fractal dimension of higher spatial complexity, but it is sensitive to contrast stretching. The variogram method is a comparatively poor estimator for all of the surfaces, particularly those with higher fractal dimensions. Similar to the fractal techniques, the spatial autocorrelation techniques are found to be useful to measure complex images but not images with low dimensionality. These fractal measurement methods can be applied directly to unclassified images and could serve as a tool for change detection and data mining.

Competition between dynamic and structural disorder in a doped triangular antiferromagnet RbFe(MoO4)2

NASA Astrophysics Data System (ADS)

Smirnov, A. I.; Soldatov, T. A.; Petrenko, O. A.; Takata, A.; Kida, T.; Hagiwara, M.; Zhitomirsky, M. E.; Shapiro, A. Ya

2018-03-01

Magnetisation measurements and electron spin resonance (ESR) spectra of a doped quasi two dimensional (2D) antiferromagnet on a triangular lattice Rb1 ‑ x K x Fe(MoO4)2 reveal a crucial change of the ground state spin configuration and a disappearance of a characteristic 1/3-magnetisation plateau at x = 0.15. According to theory for triangular antiferromagnets with a weak random modulation of the exchange bonds, this is a result of the competition between the structural and dynamic disorders. The dynamic zero-point or thermal fluctuations are known to lift the degeneracy of the mean field ground state of a triangular antiferromagnet and cause the spin configuration to be the most collinear, while the static disorder provides another selection of the ground state, with the least collinear structure. Low-level doping (x ≤ 0.15) was found to decrease the Néel temperature and saturation field by only few percent, while the magnetisation plateau disappears completely and the spin configuration is drastically changed. ESR spectra confirm an impurity-induced change of the so-called Y-type structure to an inverted Y-structure for x = 0.15. For x = 0.075 the intermediate regime with the decrease of width and weakening of flattening of 1/3-plateau was found.

Shape discrimination and concept formation in the jungle crow (Corvus macrorhynchos).

PubMed

Bogale, Bezawork Afework; Sugita, Shoei

2014-01-01

We investigated whether jungle crows can learn concepts by using printouts of shapes in a simultaneous two-alternative task. Jungle crows were first trained with a red triangle and red square until they reached the discrimination criterion (80% of correct choices in two blocks of 10 trials each). Then, we tested crows with successive transfer tests to investigate both the discrimination cues being used and concept formation ability, by using novel triangular and non-triangular stimuli. All of the jungle crows learnt to discriminate between the triangle and square during training. The discrimination performance was generally not affected either by changes in the colour of the stimuli or when both shape and colour cues conflicted, with the previously non-rewarded shape but matching colour (red square) versus rewarded shape but non-matching colour (green triangle). The use of only outlines of the familiar stimuli also did not affect discrimination behaviour of crows. In addition, crows significantly discriminated novel triangular shapes during the limited trials given, suggesting their ability to form the concept of triangularity. However, failure to discriminate when the novel stimuli size deviated from the original suggests that there is a limit to shape concept formation in a familiar-novel context in the jungle crow.

Effect of morphology and solvent on two-photon absorption of nano zinc oxide

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

Kavitha, M.K.; Haripadmam, P.C.; Gopinath, Pramod

Highlights: ► ZnO nanospheres and triangular structures synthesis by novel precipitation technique. ► The effect of precursor concentration on the size and shape of nano ZnO. ► Open aperture Z-scan measurements of the ZnO nanoparticle dispersions. ► Nanospheres exhibit higher two photon absorption coefficient than triangular nanostructures. ► Nanospheres dispersed in water exhibit higher two photon absorption coefficient than its dispersion in 2-propanol. - Abstract: In this paper, we report the effect of morphology and solvent on the two-photon absorption of nano zinc oxide. Zinc oxide nanoparticles in two different morphologies like nanospheres and triangular nanostructures are synthesized by novelmore » precipitation technique and their two-photon absorption coefficient is measured using open aperture Z-scan technique. Experimental results show that the zinc oxide nanospheres exhibit higher two-photon absorption coefficient than the zinc oxide triangular nanostructures. The zinc oxide nanospheres dispersed in water exhibit higher two-photon absorption coefficient than that of its dispersion in 2-propanol. The zinc oxide nanospheres dispersed in water shows a decrease in two-photon absorption coefficient with an increase in on-axis irradiance. The result confirms the dependence of shape and solvent on the two-photon absorption of nano zinc oxide.« less

Characterization of Trinuclear Oxo Bridged Cobalt Complexes in Isolation

NASA Astrophysics Data System (ADS)

Lang, Johannes; Fries, Daniela V.; Niedner-Schatteburg, Gereon

2018-05-01

This study elucidates molecular structures, fragmentation pathways and relative stabilities of isolated trinuclear oxo bridged cobalt complexes of the structural type [Co3O(OAc)6(Py)n]+ (OAc=acetate, Py=pyridine, n=0, 1, 2, 3). We present infrared multiple photon dissociation (IR-MPD) spectra in combination with quantum chemical calculations. They indicate that the coordination of axial pyridine ligands to the [Co3O(OAc)6]+ subunit disturbs the triangular geometry of the Co3O core. [Co3O(OAc)6]+ exhibits a nearly equilateral triangular Co3O core geometry. The coordination of one or two pyridine ligands disturbs this arrangement resulting in isosceles triangular Co3O core geometries (in the cases of n=1 and 2). Coordination of three pyridine ligands (n=3) results in an equilateral triangular Co3O core geometry as in the case of n=0. Collision induced dissociation (CID) studies reveal that the complexes undergo a consecutive elimination of pyridine and acetate ligands with increasing excitation energy. Relative stabilities of the complexes decrease with the number of coordinated pyridine ligands. The presented results help to gain a fundamental insight into the molecular structure of trinuclear oxo bridged cobalt complexes void of any external effects such as crystal packing or solvation.

Effect of Refractive Index of Substrate on Fabrication and Optical Properties of Hybrid Au-Ag Triangular Nanoparticle Arrays

PubMed Central

Liu, Jing; Chen, Yushan; Cai, Haoyuan; Chen, Xiaoyi; Li, Changwei; Yang, Cheng-Fu

2015-01-01

In this study, the nanosphere lithography (NSL) method was used to fabricate hybrid Au-Ag triangular periodic nanoparticle arrays. The Au-Ag triangular periodic arrays were grown on different substrates, and the effect of the refractive index of substrates on fabrication and optical properties was systematically investigated. At first, the optical spectrum was simulated by the discrete dipole approximation (DDA) numerical method as a function of refractive indexes of substrates and mediums. Simulation results showed that as the substrates had the refractive indexes of 1.43 (quartz) and 1.68 (SF5 glass), the nanoparticle arrays would have better refractive index sensitivity (RIS) and figure of merit (FOM). Simulation results also showed that the peak wavelength of the extinction spectra had a red shift when the medium’s refractive index n increased. The experimental results also demonstrated that when refractive indexes of substrates were 1.43 and 1.68, the nanoparticle arrays and substrate had better adhesive ability. Meanwhile, we found the nanoparticles formed a large-scale monolayer array with the hexagonally close-packed structure. Finally, the hybrid Au-Ag triangular nanoparticle arrays were fabricated on quartz and SF5 glass substrates and their experiment extinction spectra were compared with the simulated results.

A comparison of lamellar and penetrating keratoplasty outcomes: a registry study.

PubMed

Coster, Douglas J; Lowe, Marie T; Keane, Miriam C; Williams, Keryn A

2014-05-01

To investigate changing patterns of practice of keratoplasty in Australia, graft survival, visual outcomes, the influence of experience, and the surgeon learning curve for endothelial keratoplasty. Observational, prospective cohort study. From a long-standing national corneal transplantation register, 13 920 penetrating keratoplasties, 858 deep anterior lamellar keratoplasties (DALKs), and 2287 endokeratoplasties performed between January 1996 and February 2013 were identified. Kaplan-Meier functions were used to assess graft survival and surgeon experience, the Pearson chi-square test was used to compare visual acuities, and linear regression was used to examine learning curves. Graft survival. The total number of corneal grafts performed annually is increasing steadily. More DALKs but fewer penetrating grafts are being performed for keratoconus, and more endokeratoplasties but fewer penetrating grafts are being performed for Fuchs' dystrophy and pseudophakic bullous keratopathy. In 2012, 1482 grafts were performed, compared with 955 in 2002, translating to a requirement for 264 extra corneal donors across the country in 2012. Comparing penetrating grafts and DALKs performed for keratoconus over the same era, both graft survival (P <0.001) and visual outcomes (P <0.001) were significantly better for penetrating grafts. Survival of endokeratoplasties performed for Fuchs' dystrophy or pseudophakic bullous keratopathy was poorer than survival of penetrating grafts for the same indications over the same era (P <0.001). Visual outcomes were significantly better for penetrating grafts than for endokeratoplasties performed for Fuchs' dystrophy (P <0.001), but endokeratoplasties achieved better visual outcomes than penetrating grafts for pseudophakic bullous keratopathy (P <0.001). Experienced surgeons (>100 registered keratoplasties) achieved significantly better survival of endokeratoplasties (P <0.001) than surgeons who had performed fewer grafts (<100 registered keratoplasties). In the hands of experienced, high-volume surgeons, endokeratoplasty failures occurred even after 100 grafts had been performed. More corneal transplants, especially DALKs and endokeratoplasties, are being performed in Australia than ever before. Survival of DALKs and endokeratoplasties is worse than the survival of penetrating grafts performed for the same indications over the same timeframe. Many endokeratoplasties fail early, but the evidence for a surgeon learning curve is unconvincing. Copyright © 2014 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Teen trauma without the drama: outcomes of adolescents treated at Ohio adult versus pediatric trauma centers.

PubMed

Walther, Ashley E; Pritts, Timothy A; Falcone, Richard A; Hanseman, Dennis J; Robinson, Bryce R H

2014-07-01

The optimal treatment facility for adolescent trauma patients is controversial. We sought to investigate risk-adjusted outcomes of adolescents treated at adult-only trauma centers (ATCs) versus pediatric-only trauma centers (PTCs) in a state system with legislated American College of Surgeons-verified institutions to determine ideal prehospital referral patterns. The Ohio Trauma Registry was queried for patients 15 years to 19 years with a length of stay (LOS) greater than 1 day at ATC (Level 1) or PTC (Levels 1 and 2) from 2008 to 2012. Race, sex, emergency department vital signs, Injury Severity Score (ISS), computed tomography, and ultrasound imaging were reviewed. Outcomes by mechanism of injury included ventilator days, intensive care unit LOS, hospital LOS, and mortality. Statistical analysis was performed using χ test, t test, and Wilcoxon rank-sum test. Propensity score-based risk adjustment matching was used to compare groups (propensity score within 0.01, ISS within 5). Of 5,793 adolescents examined, (84% blunt, 16% penetrating) 66% were treated at an ATC. In unmatched comparisons, age, ISS, vital signs, and mortality differed significantly between centers (p < 0.01). For adolescents with blunt injury, more males (71.6% vs. 66.3%, p < 0.01) and nonwhites (19.2% vs. 15.8%, p < 0.01) were seen at PTCs. For penetrating trauma, more males (88.6% vs. 50.8%, p < 0.01) and nonwhites (66.4% vs. 34.3%, p < 0.01) were admitted to ATCs. In 873 propensity-matched pairs for blunt trauma and 95 propensity-matched pairs of penetrating injuries, no differences were seen in a priori outcomes. Imaging (blunt, head computed tomography and abdominal ultrasound, p < 0.01; penetrating, abdominal ultrasound, p = 0.02) was more common at ATCs. Major outcome differences for injured adolescents do not exist between ATCs and PTCs, regardless of injury pattern. Imaging remains more prevalent at ATCs. In a state system with mandatory American College of Surgeons-verified centers, injury patterns need not dictate triage decisions for adolescents. Epidemiologic study, level III.

Projection-Based 3D Printing of Cell Patterning Scaffolds with Multiscale Channels.

PubMed

Xue, Dai; Wang, Yancheng; Zhang, Jiaxin; Mei, Deqing; Wang, Yue; Chen, Shaochen

2018-06-13

To fully actualize artificial, cell-laden biological models in tissue engineering, such as 3D organoids and organs-on-a-chip systems, cells need to be patterned such that they can precisely mimic natural microenvironments in vitro. Despite increasing interest in this area, patterning cells at multiscale (∼10 μm to 10 mm) remains a significant challenge in bioengineering. Here, we report a projection-based 3D printing system that achieves rapid and high-resolution fabrication of hydrogel scaffolds featuring intricate channels for multiscale cell patterning. Using this system, we were able to use biocompatible poly(ethylene glycol)diacrylate in fabricating a variety of scaffold architectures, ranging from regular geometries such as serpentine, spiral, and fractal-like to more irregular/intricate geometries, such as biomimetic arborescent and capillary networks. A red food dye solution was able to freely fill all channels in the scaffolds, from the trunk (>1100 μm in width) to the small branch (∼17 μm in width) without an external pump. The dimensions of the printed scaffolds remained stable over 3 days while being immersed in Dulbecco's phosphate-buffered saline at 37 °C, and a penetration analysis revealed that these scaffolds are suitable for metabolic and nutrient transport. Cell patterning experiments showed that red fluorescent protein-transfected A549 human nonsmall lung cancer cells adhered well in the scaffolds' channels, and showed further attachment and penetration during cell culture proliferation.

Imaging assessment of penetrating injury of the neck and face.

PubMed

Offiah, Curtis; Hall, Edward

2012-10-01

Penetrating trauma of the neck and face is a frequent presentation to acute emergency, trauma and critical care units. There remains a steady incidence of both gunshot penetrating injury to the neck and face as well as non-missile penetrating injury-largely, but not solely, knife-related. Optimal imaging assessment of such injuries therefore remains an on-going requirement of the general and specialised radiologist. The anatomy of the neck and face-in particular, vascular, pharyngo-oesophageal, laryngo-tracheal and neural anatomy-demands a more specialised and selective management plan which incorporates specific imaging techniques. The current treatment protocol of injuries of the neck and face has seen a radical shift away from expectant surgical exploration in the management of such injuries, largely as a result of advances in the diagnostic capabilities of multi-detector computed tomography angiography (MDCTA), which is now the first-line imaging modality of choice in such cases. This review aims to highlight ballistic considerations, differing imaging modalities, including MDCTA, that might be utilised to assist in the accurate assessment of these injuries as well as the specific radiological features and patterns of specific organ-system injuries that should be considered and communicated to surgical and critical care teams. TEACHING POINTS : • MDCTA is the first-line imaging modality in penetrating trauma of the neck and, often, of the face • The inherent deformability of a bullet is a significant factor in its tissue-damaging capabilities • MDCTA can provide accurate assessment of visceral injury of the neck as well as vascular injury • Penetrating facial trauma warrants radiological assessment of key adjacent anatomical structures • In-driven fragments of native bone potentiate tissue damage in projectile penetrating facial trauma.

Different patterns of nuclear and mitochondrial penetration by the G3 PAMAM dendrimer and its biotin–pyridoxal bioconjugate BC-PAMAM in normal and cancer cells in vitro

PubMed Central

Uram, Łukasz; Szuster, Magdalena; Filipowicz, Aleksandra; Gargasz, Krzysztof; Wołowiec, Stanisław; Wałajtys-Rode, Elżbieta

2015-01-01

The intracellular localization and colocalization of a fluorescently labeled G3 amine-terminated cationic polyamidoamine (PAMAM) dendrimer and its biotin–pyridoxal (BC-PAMAM) bioconjugate were investigated in a concentration-dependent manner in normal human fibroblast (BJ) and squamous epithelial carcinoma (SCC-15) cell lines. After 24 hours treatment, both cell lines revealed different patterns of intracellular dendrimer accumulation depending on their cytotoxic effects. Cancer cells exhibited much higher (20-fold) tolerance for native PAMAM treatment than fibroblasts, whereas BC-PAMAM was significantly toxic only for fibroblasts at 50 µM concentration. Fibroblasts accumulated the native and bioconjugated dendrimers in a concentration-dependent manner at nontoxic range of concentration, with significantly lower bioconjugate loading. After reaching the cytotoxicity level, fluorescein isothiocyanate-PAMAM accumulation remains at high, comparable level. In cancer cells, native PAMAM loading at higher, but not cytotoxic concentrations, was kept at constant level with a sharp increase at toxic concentration. Mander’s coefficient calculated for fibroblasts and cancer cells confirmed more efficient native PAMAM penetration as compared to BC-PAMAM. Significant differences in nuclear dendrimer penetration were observed for both cell lines. In cancer cells, PAMAM signals amounted to ~25%–35% of the total nuclei area at all investigated concentrations, with lower level (15%–25%) observed for BC-PAMAM. In fibroblasts, the dendrimer nuclear signal amounted to 15% at nontoxic and up to 70% at toxic concentrations, whereas BC-PAMAM remained at a lower concentration-dependent level (0.3%–20%). Mitochondrial localization of PAMAM and BC-PAMAM revealed similar patterns in both cell lines, depending on the extracellular dendrimer concentration, and presented significantly lower signals from BC-PAMAM, which correlated well with the cytotoxicity. PMID:26379435

Low-Speed Static Stability and Control Characteristics of a Model of a Right Triangular Pyramid Reentry Configuration

NASA Technical Reports Server (NTRS)

Paulson, John W.

1959-01-01

An investigation of the low-speed static stability and control characteristics of a model of a right triangular pyramid reentry configuration has been made in the Langley free-flight tunnel. The investigation showed that the model had generally satisfactory longitudinal and lateral static stability characteristics. The maximum lift-drag ratio was increased from about 3 to 5 by boattailing the base of the model.

Cobalt-doping-induced synthesis of ceria nanodisks and their significantly enhanced catalytic activity.

PubMed

Guo, Xiao-Hui; Mao, Chao-Chao; Zhang, Ji; Huang, Jun; Wang, Wa-Nv; Deng, Yong-Hui; Wang, Yao-Yu; Cao, Yong; Huang, Wei-Xin; Yu, Shu-Hong

2012-05-21

High-quality cobalt-doped ceria nanostructures with triangular column, triangular slab, and disklike shapes are synthesized by tuning the doping amount of cobalt nitrate in a facile hydrothermal reaction. The cobalt-doped ceria nanodisks display significantly enhanced catalytic activity in CO oxidation due to exposed highly active crystal planes and the presence of numerous surface defects. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Mean-Field Scaling of the Superfluid to Mott Insulator Transition in a 2D Optical Superlattice.

PubMed

Thomas, Claire K; Barter, Thomas H; Leung, Tsz-Him; Okano, Masayuki; Jo, Gyu-Boong; Guzman, Jennie; Kimchi, Itamar; Vishwanath, Ashvin; Stamper-Kurn, Dan M

2017-09-08

The mean-field treatment of the Bose-Hubbard model predicts properties of lattice-trapped gases to be insensitive to the specific lattice geometry once system energies are scaled by the lattice coordination number z. We test this scaling directly by comparing coherence properties of ^{87}Rb gases that are driven across the superfluid to Mott insulator transition within optical lattices of either the kagome (z=4) or the triangular (z=6) geometries. The coherent fraction measured for atoms in the kagome lattice is lower than for those in a triangular lattice with the same interaction and tunneling energies. A comparison of measurements from both lattices agrees quantitatively with the scaling prediction. We also study the response of the gas to a change in lattice geometry, and observe the dynamics as a strongly interacting kagome-lattice gas is suddenly "hole doped" by introducing the additional sites of the triangular lattice.

Optimized up-down asymmetry to drive fast intrinsic rotation in tokamaks

NASA Astrophysics Data System (ADS)

Ball, Justin; Parra, Felix I.; Landreman, Matt; Barnes, Michael

2018-02-01

Breaking the up-down symmetry of the tokamak poloidal cross-section can significantly increase the spontaneous rotation due to turbulent momentum transport. In this work, we optimize the shape of flux surfaces with both tilted elongation and tilted triangularity in order to maximize this drive of intrinsic rotation. Nonlinear gyrokinetic simulations demonstrate that adding optimally-tilted triangularity can double the momentum transport of a tilted elliptical shape. This work indicates that tilting the elongation and triangularity in an ITER-like device can reduce the energy transport and drive intrinsic rotation with an Alfvén Mach number of roughly 1% . This rotation is four times larger than the rotation expected in ITER and is approximately what is needed to stabilize MHD instabilities. It is shown that this optimal shape can be created using the shaping coils of several present-day experiments.

Tailoring graphene magnetism by zigzag triangular holes: A first-principles thermodynamics study

DOE PAGES

Khan, Muhammad Ejaz; Zhang, P.; Sun, Yi -Yang; ...

2016-03-30

In this study, we discuss the thermodynamic stability and magnetic property of zigzag triangular holes (ZTHs) in graphene based on the results of first-principles density functional theory calculations. We find that ZTHs with hydrogen-passivated edges in mixed sp 2/sp 3 configurations (z 211) could be readily available at experimental thermodynamic conditions, but ZTHs with 100% sp 2 hydrogen-passivation (z 1) could be limitedly available at high temperature and ultra-high vacuum conditions. Graphene magnetization near the ZTHs strongly depends on the type and the size of the triangles. While metallic z 1 ZTHs exhibit characteristic edge magnetism due to the same-sublatticemore » engineering, semiconducting z 211 ZTHs do show characteristic corner magnetism when the size is small < 2 nm. Our findings could be useful for experimentally tailoring metal-free carbon magnetism by simply fabricating triangular holes in graphene.« less

A fast and accurate dihedral interpolation loop subdivision scheme

NASA Astrophysics Data System (ADS)

Shi, Zhuo; An, Yalei; Wang, Zhongshuai; Yu, Ke; Zhong, Si; Lan, Rushi; Luo, Xiaonan

2018-04-01

In this paper, we propose a fast and accurate dihedral interpolation Loop subdivision scheme for subdivision surfaces based on triangular meshes. In order to solve the problem of surface shrinkage, we keep the limit condition unchanged, which is important. Extraordinary vertices are handled using modified Butterfly rules. Subdivision schemes are computationally costly as the number of faces grows exponentially at higher levels of subdivision. To address this problem, our approach is to use local surface information to adaptively refine the model. This is achieved simply by changing the threshold value of the dihedral angle parameter, i.e., the angle between the normals of a triangular face and its adjacent faces. We then demonstrate the effectiveness of the proposed method for various 3D graphic triangular meshes, and extensive experimental results show that it can match or exceed the expected results at lower computational cost.

Cavity mode enhancement of terahertz emission from equilateral triangular microstrip antennas of the high-Tc superconductor Bi2Sr2CaCu2O8+δ

NASA Astrophysics Data System (ADS)

Doty, Constance; Cerkoney, Daniel; Gramajo, Ashley; Campbell, Tyler; Reid, Candy; Morales, Manuel; Delfanazari, Kaveh; Yamamoto, Takashi; Tsujimoto, Manabu; Kashiwagi, Takanari; Watanabe, Chiharu; Minami, Hidetoshi; Kadowaki, Kazuo; Klemm, Richard

We study the transverse magnetic (TM) electromagnetic cavity mode wave functions for an ideal equilateral triangular microstrip antenna exhibiting C3v point group symmetry, which restricts the number of TM(n,m) modes to | m - n | = 3 p , where the integer p > 0 for the modes odd and even about the three mirror planes, but p = 0 can also exist for the even modes. We calculate the wave functions and the power distribution forms from the uniform Josephson current source and from the excitation of one of these cavity modes, and fit data on an early equilateral triangular Bi2Sr2CaCu2O8+δ mesa, for which the C3v symmetry was apparently broken. Work supported in part by the UCF RAMP, JSPS Fellowship, CREST-JST, and WPI-MANA.

Design of Miniaturized Double-Negative Material for Specific Absorption Rate Reduction in Human Head

PubMed Central

Faruque, Mohammad Rashed Iqbal; Islam, Mohammad Tariqul

2014-01-01

In this study, a double-negative triangular metamaterial (TMM) structure, which exhibits a resounding electric response at microwave frequency, was developed by etching two concentric triangular rings of conducting materials. A finite-difference time-domain method in conjunction with the lossy-Drude model was used in this study. Simulations were performed using the CST Microwave Studio. The specific absorption rate (SAR) reduction technique is discussed, and the effects of the position of attachment, the distance, and the size of the metamaterials on the SAR reduction are explored. The performance of the double-negative TMMs in cellular phones was also measured in the cheek and the tilted positions using the COMOSAR system. The TMMs achieved a 52.28% reduction for the 10 g SAR. These results provide a guideline to determine the triangular design of metamaterials with the maximum SAR reducing effect for a mobile phone. PMID:25350398

Design of miniaturized double-negative material for specific absorption rate reduction in human head.

PubMed

Faruque, Mohammad Rashed Iqbal; Islam, Mohammad Tariqul

2014-01-01

In this study, a double-negative triangular metamaterial (TMM) structure, which exhibits a resounding electric response at microwave frequency, was developed by etching two concentric triangular rings of conducting materials. A finite-difference time-domain method in conjunction with the lossy-Drude model was used in this study. Simulations were performed using the CST Microwave Studio. The specific absorption rate (SAR) reduction technique is discussed, and the effects of the position of attachment, the distance, and the size of the metamaterials on the SAR reduction are explored. The performance of the double-negative TMMs in cellular phones was also measured in the cheek and the tilted positions using the COMOSAR system. The TMMs achieved a 52.28% reduction for the 10 g SAR. These results provide a guideline to determine the triangular design of metamaterials with the maximum SAR reducing effect for a mobile phone.

High-Order Residual-Distribution Schemes for Discontinuous Problems on Irregular Triangular Grids

NASA Technical Reports Server (NTRS)

Mazaheri, Alireza; Nishikawa, Hiroaki

2016-01-01

In this paper, we develop second- and third-order non-oscillatory shock-capturing hyperbolic residual distribution schemes for irregular triangular grids, extending our second- and third-order schemes to discontinuous problems. We present extended first-order N- and Rusanov-scheme formulations for hyperbolic advection-diffusion system, and demonstrate that the hyperbolic diffusion term does not affect the solution of inviscid problems for vanishingly small viscous coefficient. We then propose second- and third-order blended hyperbolic residual-distribution schemes with the extended first-order Rusanov-scheme. We show that these proposed schemes are extremely accurate in predicting non-oscillatory solutions for discontinuous problems. We also propose a characteristics-based nonlinear wave sensor for accurately detecting shocks, compression, and expansion regions. Using this proposed sensor, we demonstrate that the developed hyperbolic blended schemes do not produce entropy-violating solutions (unphysical stocks). We then verify the design order of accuracy of these blended schemes on irregular triangular grids.

Tailoring graphene magnetism by zigzag triangular holes: A first-principles thermodynamics study

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

Khan, Muhammad Ejaz; Zhang, P.; Kim, Yong-Hyun, E-mail: yong.hyun.kim@kaist.ac.kr

We discuss the thermodynamic stability and magnetic property of zigzag triangular holes (ZTHs) in graphene based on the results of first-principles density functional theory calculations. We find that ZTHs with hydrogen-passivated edges in mixed sp{sup 2}/sp{sup 3} configurations (z{sub 211}) could be readily available at experimental thermodynamic conditions, but ZTHs with 100% sp{sup 2} hydrogen-passivation (z{sub 1}) could be limitedly available at high temperature and ultra-high vacuum conditions. Graphene magnetization near the ZTHs strongly depends on the type and the size of the triangles. While metallic z{sub 1} ZTHs exhibit characteristic edge magnetism due to the same-sublattice engineering, semiconducting z{submore » 211} ZTHs do show characteristic corner magnetism when the size is small <2 nm. Our findings could be useful for experimentally tailoring metal-free carbon magnetism by simply fabricating triangular holes in graphene.« less

Spin-Chirality-Driven Ferroelectricity on a Perfect Triangular Lattice Antiferromagnet

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

Mitamura, H.; Watanuki, R.; Kaneko, Koji

Magnetic field (B) variation of the electrical polarization P c ( ∥c) of the perfect triangular lattice antiferromagnet RbFe(MoO 4) 2 is examined up to the saturation point of the magnetization for B⊥c. P c is observed only in phases for which chirality is predicted in the in-plane magnetic structures. No strong anomaly is observed in P c at the field at which the spin modulation along the c axis, and hence the spin helicity, exhibits a discontinuity to the commensurate state. These results indicate that the ferroelectricity in this compound originates predominantly from the spin chirality, the explanation ofmore » which would require a new mechanism for magnetoferroelectricity. Lastly, the obtained field-temperature phase diagrams of ferroelectricity well agree with those theoretically predicted for the spin chirality of a Heisenberg spin triangular lattice antiferromagnet.« less

Spin-Chirality-Driven Ferroelectricity on a Perfect Triangular Lattice Antiferromagnet

DOE PAGES

Mitamura, H.; Watanuki, R.; Kaneko, Koji; ...

2014-10-01

Magnetic field (B) variation of the electrical polarization P c ( ∥c) of the perfect triangular lattice antiferromagnet RbFe(MoO 4) 2 is examined up to the saturation point of the magnetization for B⊥c. P c is observed only in phases for which chirality is predicted in the in-plane magnetic structures. No strong anomaly is observed in P c at the field at which the spin modulation along the c axis, and hence the spin helicity, exhibits a discontinuity to the commensurate state. These results indicate that the ferroelectricity in this compound originates predominantly from the spin chirality, the explanation ofmore » which would require a new mechanism for magnetoferroelectricity. Lastly, the obtained field-temperature phase diagrams of ferroelectricity well agree with those theoretically predicted for the spin chirality of a Heisenberg spin triangular lattice antiferromagnet.« less

Molecular phylogeny of moth-specialized spider sub-family Cyrtarachninae, which includes bolas spiders.

PubMed

Tanikawa, Akio; Shinkai, Akira; Miyashita, Tadashi

2014-11-01

The evolutionary process of the unique web architectures of spiders of the sub-family Cyrtarachninae, which includes the triangular web weaver, bolas spider, and webless spider, is thought to be derived from reduction of orbicular 'spanning-thread webs' resembling ordinal orb webs. A molecular phylogenetic analysis was conducted to explore this hypothesis using orbicular web spiders Cyrtarachne, Paraplectana, Poecilopachys, triangular web spider Pasilobus, bolas spiders Ordgarius and Mastophora, and webless spider Celaenia. The phylogeny inferred from partial sequences of mt-COI, nuclear 18S-rRNA and 28S-rRNA showed that the common ancestor of these spiders diverged into two clades: a spanning-thread web clade and a bolas or webless clade. This finding suggests that the triangular web evolved by reduction of an orbicular spanning web, but that bolas spiders evolved in the early stage, which does not support the gradual web reduction hypothesis.

Domain decomposition methods in aerodynamics

NASA Technical Reports Server (NTRS)

Venkatakrishnan, V.; Saltz, Joel

1990-01-01

Compressible Euler equations are solved for two-dimensional problems by a preconditioned conjugate gradient-like technique. An approximate Riemann solver is used to compute the numerical fluxes to second order accuracy in space. Two ways to achieve parallelism are tested, one which makes use of parallelism inherent in triangular solves and the other which employs domain decomposition techniques. The vectorization/parallelism in triangular solves is realized by the use of a recording technique called wavefront ordering. This process involves the interpretation of the triangular matrix as a directed graph and the analysis of the data dependencies. It is noted that the factorization can also be done in parallel with the wave front ordering. The performances of two ways of partitioning the domain, strips and slabs, are compared. Results on Cray YMP are reported for an inviscid transonic test case. The performances of linear algebra kernels are also reported.

Prediction the concentration of graphite direct exfoliation by liquid solution with solubility parameters map

NASA Astrophysics Data System (ADS)

Liang, Ko-Yuan; Yang, Wein-Duo

2018-01-01

This study is to discuss solvent selection with graphene dispersion concentration of directly exfoliation graphite. That limiting boundaries of fractional cohesion parameters will be draw on the triangular diagram to prediction and estimate. It is based on the literature of data and check with experimental or other literature results, include organic solution, aqueous solution and ionic liquid. In this work, we found that estimated the graphene dispersion concentration by distance (Ra) of Hansen solubility parameters (HSP) between graphene and solvent, the lower Ra; the higher concentration, some case the lower Ra; the lower dispersion concentration (such as acetone). It is compatible with the graphene dispersion concentration on the Hansen space or Triangular fractional cohesion parameters dispersion diagram. From Triangular fractional cohesion parameters dispersion diagram, 2D maps are more convenient for researchers than 3D maps of Hansen space and quickly to find the appropriate combination of solvents for different application.

Opening and closing of band gaps in magnonic waveguide by rotating the triangular antidots - A micromagnetic study

NASA Astrophysics Data System (ADS)

Vivek, T.; Bhoomeeswaran, H.; Sabareesan, P.

2018-05-01

Spin waves in ID periodic triangular array of antidots are encarved in a permalloy magnonic waveguide is investigated through micromagnetic simulation. The effect of the rotating array of antidots and in-plane rotation of the scattering centers on the band structure are investigated, to indicate new possibilities of fine tuning of spin-wave filter pass and stop bands. The results show that, the opening and closing of band gaps paves a way for band pass and stop filters on waveguide. From the results, the scattering center and strong spatial distribution field plays crucible role for controlling opening and closing bandgap width of ˜12 GHz for 0° rotation. We have obtained a single narrow bandgap of width 1GHz is obtained for 90° rotation of the antidot. Similarly, the tunability is achieved for desired microwave applications done by rotating triangular antidots with different orientation.

Domain decomposition by the advancing-partition method for parallel unstructured grid generation

NASA Technical Reports Server (NTRS)

Banihashemi, legal representative, Soheila (Inventor); Pirzadeh, Shahyar Z. (Inventor)

2012-01-01

In a method for domain decomposition for generating unstructured grids, a surface mesh is generated for a spatial domain. A location of a partition plane dividing the domain into two sections is determined. Triangular faces on the surface mesh that intersect the partition plane are identified. A partition grid of tetrahedral cells, dividing the domain into two sub-domains, is generated using a marching process in which a front comprises only faces of new cells which intersect the partition plane. The partition grid is generated until no active faces remain on the front. Triangular faces on each side of the partition plane are collected into two separate subsets. Each subset of triangular faces is renumbered locally and a local/global mapping is created for each sub-domain. A volume grid is generated for each sub-domain. The partition grid and volume grids are then merged using the local-global mapping.

Indentation of Graphene-Covered Atomic Force Microscopy Probe Across a Lipid Bilayer Membrane: Effect of Tip Shape, Size, and Surface Hydrophobicity.

PubMed

Lv, Kang; Li, Yinfeng

2018-06-21

Understanding the interaction of graphene with cell membranes is crucial to the development of graphene-based biological applications and the management of graphene safety issues. To help reveal the key factors controlling the interaction between graphene and cell membranes, here we adopt the dissipative particle dynamics method to analyze the evolution of interaction force and free energy as the graphene-covered atomic force microscopy (AFM) probe indents across a lipid bilayer. The simulation results show that the graphene-covered AFM probe can cause severe deformation of the cell membrane which drives the lipid molecule to adsorb and diffuse at the surface of graphene. The breakthrough force and free energy are calculated to study the effects of the tip shape, size, and surface hydrophobicity on the piercing behaviors of graphene-covered AFM. In addition, the deformation of cell membrane can decrease the dependency of the breakthrough force on the tip shape. The analysis of surface functionalization suggests that the horizontal patterns on graphene can change the preferred orientation in the penetration process, but the vertical patterns on graphene may disrupt the cell membrane. What's more, the bending stiffness of graphene has little influence on the penetration process as graphene pierces into the cell membrane. These results provide useful guidelines for the molecular design of graphene materials with controllable cell penetrability.

RIE-based Pattern Transfer Using Nanoparticle Arrays as Etch Masks

NASA Astrophysics Data System (ADS)

Hogg, Chip; Majetich, Sara A.; Bain, James A.

2009-03-01

Nanomasking is used to transfer the pattern of a self-assembled array of nanoparticles into an underlying thin film, for potential use as bit-patterned media. We have used this process to investigate the limits of pattern transfer, as a function of gap size in the pattern. Reactive Ion Etching (RIE) is our chosen process, since the gaseous reaction products and high chemical selectivity are ideal features for etching very small gaps. Interstitial surfactant is removed with an O2 plasma, allowing the etchants to penetrate between the particles. Their pattern is transferred into an intermediate SiO2 mask using a CH4-based RIE. This patterned SiO2 layer is finally used as a mask for the MeOH-based RIE which patterns the magnetic film. We present cross-sectional TEM characterization of the etch profiles, as well as magnetic characterization of the film before and after patterning.

Mathematical Investigation of Gamma Ray and Neutron Absorption Grid Patterns for Homeland Defense Related Fourier Imaging Systems

NASA Technical Reports Server (NTRS)

Boccio, Dona

2003-01-01

Terrorist suitcase nuclear devices typically using converted Soviet tactical nuclear warheads contain several kilograms of plutonium. This quantity of plutonium emits a significant number of gamma rays and neutrons as it undergoes radioactive decay. These gamma rays and neutrons normally penetrate ordinary matter to a significant distance. Unfortunately this penetrating quality of the radiation makes imaging with classical optics impractical. However, this radiation signature emitted by the nuclear source may be sufficient to be imaged from low-flying aerial platforms carrying Fourier imaging systems. The Fourier imaging system uses a pair of co-aligned absorption grids to measure a selected range of spatial frequencies from an object. These grids typically measure the spatial frequency in only one direction at a time. A grid pair that looks in all directions simultaneously would be an improvement over existing technology. A number of grid pairs governed by various parameters were investigated to solve this problem. By examining numerous configurations, it became apparent that an appropriate spiral pattern could be made to work. A set of equations was found to describe a grid pattern that produces straight fringes. Straight fringes represent a Fourier transform of a point source at infinity. An inverse Fourier transform of this fringe pattern would provide an accurate image (location and intensity) of a point source.

Complex bud architecture and cell‐specific chemical patterns enable supercooling of Picea abies bud primordia

PubMed Central

Munkler, Caspar; Resnyak, Anna; Zimmermann, Sonja; Tuong, Tan D.; Gierlinger, Notburga; Müller, Thomas; Livingston, David P.; Neuner, Gilbert

2017-01-01

Abstract Bud primordia of Picea abies, despite a frozen shoot, stay ice free down to −50 °C by a mechanism termed supercooling whose biophysical and biochemical requirements are poorly understood. Bud architecture was assessed by 3D—reconstruction, supercooling and freezing patterns by infrared video thermography, freeze dehydration and extraorgan freezing by water potential measurements, and cell‐specific chemical patterns by Raman microscopy and mass spectrometry imaging. A bowl‐like ice barrier tissue insulates primordia from entrance by intrinsic ice. Water repellent and densely packed bud scales prevent extrinsic ice penetration. At −18 °C, break‐down of supercooling was triggered by intrinsic ice nucleators whereas the ice barrier remained active. Temperature‐dependent freeze dehydration (−0.1 MPa K−1) caused accumulation of extraorgan ice masses that by rupture of the shoot, pith tissue are accommodated in large voids. The barrier tissue has exceptionally pectin‐rich cell walls and intercellular spaces, and the cell lumina were lined or filled with proteins, especially near the primordium. Primordial cells close to the barrier accumulate di, tri and tetrasaccharides. Bud architecture efficiently prevents ice penetration, but ice nucleators become active inside the primordium below a temperature threshold. Biochemical patterns indicate a complex cellular interplay enabling supercooling and the necessity for cell‐specific biochemical analysis. PMID:28960368

Possible nodal vortex state in CeRu2

NASA Astrophysics Data System (ADS)

Kadono, R.; Higemoto, W.; Koda, A.; Ohishi, K.; Yokoo, T.; Akimitsu, J.; Hedo, M.; Inada, Y.; O¯nuki, Y.; Yamamoto, E.; Haga, Y.

2001-06-01

The microscopic property of magnetic vortices in the mixed state of a high-quality CeRu2 crystal has been studied by muon spin rotation. We have found that the spatial distribution of magnetic induction B(r) probed by muons is perfectly described by the London model for the triangular vortex lattice with appropriate modifications to incorporate the high-field cutoff around the vortex core and the effect of long-range defects in the vortex lattice structure at lower fields. The vortex core radius is proportional to H(β-1)/2 with β~=0.53 (H being the magnetic field), which is in good agreement with the recently observed nonlinear field dependence of the electronic specific heat coefficient γ~Hβ. In particular, the anomalous increase of magnetic penetration depth in accordance with the peak effect in dc magnetization (>=H*~=3 T at 2.0 K) has been confirmed; this cannot be explained by the conventional pair-breaking effect due to magnetic field. In addition, the spontaneous enhancement of flux pinning, which is also associated with the peak effect, has been demonstrated microscopically. These results strongly suggest the onset of collective pinning induced by a new vortex state having an anomalously enhanced quasiparticle density of states for H>=H*.

MD and BCA simulations of He and H bombardment of fuzz in bcc elements

NASA Astrophysics Data System (ADS)

Klaver, T. P. C.; Zhang, S.; Nordlund, K.

2017-08-01

We present results of MD simulations of low energy He ion bombardment of low density fuzz in bcc elements. He ions can penetrate several micrometers into sparse fuzz, which allows for a sufficient He flux through it to grow the fuzz further. He kinetic energy falls off exponentially with penetration depth. A BCA code was used to carry out the same ion bombardment on the same fuzz structures as in MD simulations, but with simpler, 10 million times faster calculations. Despite the poor theoretical basis of the BCA at low ion energies, and the use of somewhat different potentials in MD and BCA calculations, the ion penetration depths predicted by BCA are only ∼12% less than those predicted by MD. The MD-BCA differences are highly systematic and trends in the results of the two methods are very similar. We have carried out more than 200 BCA calculation runs of ion bombardment of fuzz, in which parameters in the ion bombardment process were varied. For most parameters, the results show that the ion bombardment process is quite generic. The ion species (He or H), ion mass, fuzz element (W, Ta, Mo, Fe) and fuzz element lattice parameter turned out to have a modest influence on ion penetration depths at most. An off-normal angle of incidence strongly reduces the ion penetration depth. Increasing the ion energy increases the ion penetration, but the rate by which ion energy drops off at high ion energies follows the same exponential pattern as at lower energies.

Effective side length formula for resonant frequency of equilateral triangular microstrip antenna

NASA Astrophysics Data System (ADS)

Guney, Kerim; Kurt, Erhan

2016-02-01

A novel and accurate expression is obtained by employing the differential evolution algorithm for the effective side length (ESL) of the equilateral triangular microstrip antenna (ETMA). This useful formula allows the antenna engineers to accurately calculate the ESL of the ETMA. The computed resonant frequencies (RFs) show very good agreement with the experimental RFs when this accurate ESL formula is utilised for the computation of the RFs for the first five modes.

Aerodynamic Characteristics and Flying Qualities of a Tailless Triangular-wing Airplane Configuration as Obtained from Flights of Rocket-propelled Models at Transonic and Supersonic Speeds

NASA Technical Reports Server (NTRS)

Mitcham, Grady L; Stevens, Joseph E; Norris, Harry P

1956-01-01

A flight investigation of rocket-powered models of a tailless triangular-wing airplane configuration was made through the transonic and low supersonic speed range at the Langley Pilotless Aircraft Research Station at Wallops Island, Va. An analysis of the aerodynamic coefficients, stability derivatives, and flying qualities based on the results obtained from the successful flight tests of three models is presented.

High precision triangular waveform generator

DOEpatents

Mueller, Theodore R.

1983-01-01

An ultra-linear ramp generator having separately programmable ascending and descending ramp rates and voltages is provided. Two constant current sources provide the ramp through an integrator. Switching of the current at current source inputs rather than at the integrator input eliminates switching transients and contributes to the waveform precision. The triangular waveforms produced by the waveform generator are characterized by accurate reproduction and low drift over periods of several hours. The ascending and descending slopes are independently selectable.

High-precision triangular-waveform generator

DOEpatents

Mueller, T.R.

1981-11-14

An ultra-linear ramp generator having separately programmable ascending and decending ramp rates and voltages is provided. Two constant current sources provide the ramp through an integrator. Switching of the current at current source inputs rather than at the integrator input eliminates switching transients and contributes to the waveform precision. The triangular waveforms produced by the waveform generator are characterized by accurate reproduction and low drift over periods of several hours. The ascending and descending slopes are independently selectable.

Double level selection in a constitutional dynamic library of coordination driven supramolecular polygons.

PubMed

Rancan, Marzio; Tessarolo, Jacopo; Casarin, Maurizio; Zanonato, Pier Luigi; Quici, Silvio; Armelao, Lidia

2014-07-21

A constitutional dynamic library (CDL) of Cu(II) metallo-supramolecular polygons has been studied as a bench test to examine an interesting selection case based on molecular recognition. Sorting of the CDL polygons is achieved through a proper guest that is hosted into the triangular metallo-macrocycle constituent. Two selection mechanisms are observed, a guest induced path and a guest templated self-assembly (virtual library approach). Remarkably, the triangular host can accommodate several guests with a degree of selectivity ranging from ∼1 to ∼10(4) for all possible guest pairs. A double level selection operates: guests drive the CDL toward the triangular polygon, and, at the same time, this is able to pick a specific guest from a set of competitive molecules, according to a selectivity-affinity correlation. Association constants of the host-guest systems have been determined. Guest competition and exchange studies have been analyzed through variable temperature UV-Vis absorption spectroscopy and single crystal X-ray diffraction studies. Molecular structures and electronic properties of the triangular polygon and of the host-guest systems also have been studied by means of all electrons density functional theory (DFT) and time-dependent density functional theory (TDDFT) calculations including dispersive contributions. DFT outcomes ultimately indicate the dispersive nature of the host-guest interactions, while TDDFT results allow a thorough assignment of the host and host-guests spectral features.

RMP ELM Suppression in DIII-D Plasmas with ITER Similar Shapes and Collisionalities

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

Evans, T.E.; Fenstermacher, M. E.; Moyer, R.A.

2008-01-01

Large Type-I edge localized modes (ELMs) are completely eliminated with small n = 3 resonant magnetic perturbations (RMP) in low average triangularity, = 0.26, plasmas and in ITER similar shaped (ISS) plasmas, = 0.53, with ITER relevant collisionalities ve 0.2. Significant differences in the RMP requirements and in the properties of the ELM suppressed plasmas are found when comparing the two triangularities. In ISS plasmas, the current required to suppress ELMs is approximately 25% higher than in low average triangularity plasmas. It is also found that the width of the resonant q95 window required for ELM suppression is smaller inmore » ISS plasmas than in low average triangularity plasmas. An analysis of the positions and widths of resonant magnetic islands across the pedestal region, in the absence of resonant field screening or a self-consistent plasma response, indicates that differences in the shape of the q profile may explain the need for higher RMP coil currents during ELM suppression in ISS plasmas. Changes in the pedestal profiles are compared for each plasma shape as well as with changes in the injected neutral beam power and the RMP amplitude. Implications of these results are discussed in terms of requirements for optimal ELM control coil designs and for establishing the physics basis needed in order to scale this approach to future burning plasma devices such as ITER.« less

Elementary dispersion analysis of some mimetic discretizations on triangular C-grids

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

Korn, P., E-mail: peter.korn@mpimet.mpg.de; Danilov, S.; A.M. Obukhov Institute of Atmospheric Physics, Moscow

2017-02-01

Spurious modes supported by triangular C-grids limit their application for modeling large-scale atmospheric and oceanic flows. Their behavior can be modified within a mimetic approach that generalizes the scalar product underlying the triangular C-grid discretization. The mimetic approach provides a discrete continuity equation which operates on an averaged combination of normal edge velocities instead of normal edge velocities proper. An elementary analysis of the wave dispersion of the new discretization for Poincaré, Rossby and Kelvin waves shows that, although spurious Poincaré modes are preserved, their frequency tends to zero in the limit of small wavenumbers, which removes the divergence noisemore » in this limit. However, the frequencies of spurious and physical modes become close on shorter scales indicating that spurious modes can be excited unless high-frequency short-scale motions are effectively filtered in numerical codes. We argue that filtering by viscous dissipation is more efficient in the mimetic approach than in the standard C-grid discretization. Lumping of mass matrices appearing with the velocity time derivative in the mimetic discretization only slightly reduces the accuracy of the wave dispersion and can be used in practice. Thus, the mimetic approach cures some difficulties of the traditional triangular C-grid discretization but may still need appropriately tuned viscosity to filter small scales and high frequencies in solutions of full primitive equations when these are excited by nonlinear dynamics.« less

A triangular prism solid and shell interactive mapping element for electromagnetic sheet metal forming process

NASA Astrophysics Data System (ADS)

Cui, Xiangyang; Li, She; Feng, Hui; Li, Guangyao

2017-05-01

In this paper, a novel triangular prism solid and shell interactive mapping element is proposed to solve the coupled magnetic-mechanical formulation in electromagnetic sheet metal forming process. A linear six-node "Triprism" element is firstly proposed for transient eddy current analysis in electromagnetic field. In present "Triprism" element, shape functions are given explicitly, and a cell-wise gradient smoothing operation is used to obtain the gradient matrices without evaluating derivatives of shape functions. In mechanical field analysis, a shear locking free triangular shell element is employed in internal force computation, and a data mapping method is developed to transfer the Lorentz force on solid into the external forces suffered by shell structure for dynamic elasto-plasticity deformation analysis. Based on the deformed triangular shell structure, a "Triprism" element generation rule is established for updated electromagnetic analysis, which means inter-transformation of meshes between the coupled fields can be performed automatically. In addition, the dynamic moving mesh is adopted for air mesh updating based on the deformation of sheet metal. A benchmark problem is carried out for confirming the accuracy of the proposed "Triprism" element in predicting flux density in electromagnetic field. Solutions of several EMF problems obtained by present work are compared with experiment results and those of traditional method, which are showing excellent performances of present interactive mapping element.

Cause and Cure - Deterioration in Accuracy of CFD Simulations with Use of High-Aspect-Ratio Triangular/Tetrahedral Grids

NASA Technical Reports Server (NTRS)

Chang, Sin-Chung; Chang, Chau-Lyan; Venkatachari, Balaji Shankar

2017-01-01

Traditionally high-aspect ratio triangular/tetrahedral meshes are avoided by CFD researchers in the vicinity of a solid wall, as it is known to reduce the accuracy of gradient computations in those regions. Although for certain complex geometries, the use of high-aspect ratio triangular/tetrahedral elements in the vicinity of a solid wall can be replaced by quadrilateral/prismatic elements, ability to use triangular/tetrahedral elements in such regions without any degradation in accuracy can be beneficial from a mesh generation point of view. The benefits also carry over to numerical frameworks such as the space-time conservation element and solution element (CESE), where simplex elements are the mandatory building blocks. With the requirement of the CESE method in mind, a rigorous mathematical framework that clearly identifies the reason behind the difficulties in use of such high-aspect ratio simplex elements is formulated using two different approaches and presented here. Drawing insights from the analysis, a potential solution to avoid that pitfall is also provided as part of this work. Furthermore, through the use of numerical simulations of practical viscous problems involving high-Reynolds number flows, how the gradient evaluation procedures of the CESE framework can be effectively used to produce accurate and stable results on such high-aspect ratio simplex meshes is also showcased.

Triangular osteosynthesis of vertically unstable sacrum fractures: a new concept allowing early weight-bearing.

PubMed

Schildhauer, T A; Josten, Ch; Muhr, G

2006-01-01

Presentation of a new triangular osteosynthesis technique that permits early weight-bearing in vertically unstable sacral fractures. : Retrospective evaluation of a consecutive series. Level I trauma center. Thirty-four patients, twenty-eight of whom were poly-traumatized, all with vertically unstable sacral fractures. This group included eight women and twenty-six men, with a mean age of thirty-five years. Average time between trauma and definite operation was thirteen days (range 0 to 28 days). All patients underwent triangular osteosynthesis using a combination of a vertical vertebro-pelvic distraction osteosynthesis (pedicle screw system) and a transverse fixation of the sacrum fracture with either iliosacral screws or trans-sacral plating. Immediate postoperative weight-bearing was permitted postoperatively. Nineteen patients were treated with early progressive weight-bearing and advanced to full weight-bearing, on average, after twenty-three days (range 8 to 70 days). Three of the thirty-four patients (9 percent) experienced loosening of hardware, including two patients (6 percent) who required secondary intervention because of loss of the original reduction. Further complications included one pulmonary embolism (3 percent), one iatrogenic nerve lesion (3 percent), one wound necrosis (3 percent), and two local infections (6 percent). Triangular osteosynthesis is a demanding procedure that can be performed on vertically unstable sacral fractures to allow early progressive weight-bearing with an acceptable complication rate.

Ionic liquids-water interfacial preparation of triangular Ag nanoplates and their shape-dependent antibacterial activity.

PubMed

Lu, Weiwei; Yao, Kaisheng; Wang, Jianji; Yuan, Jiongliang

2015-01-01

As a class of green and designable solvents, ionic liquids (ILs) have been used extensively in inorganic synthesis. In those schemes, ILs were usually used as reaction media to replace water and organic solvents, and/or used as stabilizer and capping agents to act like an amphiphilic molecule or polymer. However, the unique properties of ILs were not fully utilized in the area of material preparation. In this study, a new protocol of "ILs-water interfacial synthesis" was developed and used for the preparation of Ag nanomaterials. Taking the advantage of tunable property of ILs-water interface, Ag nanomaterials with different morphology such as triangular nanoplates, polygonal nanoplates, and nanoparticles could be facilely obtained. Growth mechanism of the triangular Ag nanoplates has been investigated from structural characterization and molecular dynamics (MD) simulation. It was shown that growth of the nanoplates was under kinetic control mainly due to high viscosity and ionicity of the ILs. Furthermore, the antimicrobial performance of these Ag samples was tested to study the influence of shape of the Ag nanomaterials on the antimicrobial activity and the related antimicrobial mechanism. The results suggested that the efficient antimicrobial activity of the triangular Ag nanoplates was ascribed to their sharp corners and edges and large areas of active (111) crystal plane, which leads to the higher amount of leaching Ag(+) ion. Copyright © 2014 Elsevier Inc. All rights reserved.

Intimal cushions and endothelial nuclear elongation around mouse aortic branches and their spatial correspondence with patterns of lipid deposition

PubMed Central

Bond, Andrew R.; Ni, Chih-Wen; Jo, Hanjoong

2010-01-01

Spatial variation in hemodynamic stresses acting on the arterial wall may explain the nonuniform distribution of atherosclerosis. In thoracic aortas of LDL receptor/apolipoprotein E double knockout mice, lesions develop preferentially around the entire circumference of intercostal branch ostia, regardless of age, with the highest prevalence occurring upstream. Additional chevron-shaped lesions occur further upstream of the ostia. This pattern differs from the age-related ones occurring in people and rabbits. In the present study, patterns of near-wall blood flow around intercostal ostia in wild-type mice were estimated from the morphology of endothelial nuclei, which were shown in vitro to elongate in response to elevated shear stress and to align with the flow, and wall structure was assessed from confocal and scanning electron microscopy. A triangular intimal cushion surrounded the upstream part of most ostia. Nuclear length-to-width ratios were lowest over this cushion and highest at the sides of branches, regardless of age. Nuclear orientations were consistent with flow diverging around the branch. The pattern of nuclear morphology differed from the age-related ones observed in rabbits. The intimal cushion and the distribution of shear stress inferred from these observations can partly account for the pattern of lesions observed in knockout mice. Nuclear elongation in nonbranch regions was approximately constant across animals of different size, demonstrating the existence of a mechanism by which endothelial cells compensate for the dependence of mean aortic wall shear stress on body mass. PMID:19933414

Numerical Experiments of Counterflowiing Jet Effects on Supersonic Slender-Body Configurations

NASA Technical Reports Server (NTRS)

Venkatachari, Balaji Shankar; Mullane, Michael; Cheng, Gary C.; Chang, Chau-Lyan

2015-01-01

Previous studies have demonstrated that the use of counterflowing jets can greatly reduce the drag and heat loads on blunt-body geometries, especially when the long penetration mode jet condition can be established. Previously, the authors had done some preliminary numerical studies to determine the ability to establish long penetration mode jets on a typical Mach 1.6 slender configuration, and study its impact on the boom signature. The results indicated that a jet with a longer penetration length was required to achieve any impact on the boom signature of a typical Mach 1.6 slender configuration. This paper focuses on an in-depth parametric study, done using the space-time conservation element solution element Navier-Stokes flow solver, for investigating the effect of various counterflowing jet conditions/configurations on two supersonic slender-body models (cone-cylinder and quartic body of revolution). The study is aimed at gaining a better understanding of the relationship between the shock penetration length and reduction of drag and boom signature for these two supersonic slender-body configurations. Different jet flow rates, Mach numbers, nozzle jet exit diameters and jet-to-base diameter ratios were examined. The results show the characteristics of a short-to-long-to-short penetration-mode pattern with the increase of jet mass flow rates, observed across various counterflowing jet nozzle configurations. Though the optimal shock penetration length for potential boom-signature mitigation is tied to the long penetration mode, it often results in a very unsteady flow and leads to large oscillations of surface pressure and drag. Furthermore, depending on the geometry of the slender body, longer jet penetration did not always result in maximum drag reduction. For the quartic geometry, the maximum drag reduction corresponds well to the longest shock penetration length, while this was not the case for the cone-cylinder-as the geometry was already optimized for drag. Numerical results and assessments obtained from this parametric study along with the recommendation for future implementation of counterflowing jets as a means for drag and noise reduction are detailed in this paper.

Nanoscale patterning of gold-coated optical fibers for improved plasmonic sensing

NASA Astrophysics Data System (ADS)

Antohe, Iulia; Spasic, Dragana; Delport, Filip; Li, Jiaqi; Lammertyn, Jeroen

2017-05-01

Merging surface plasmon resonance (SPR) to fiber optic (FO) technology has brought remarkable achievements in the field by offering attractive advantages over the conventional prism-based SPR platforms, such as simplicity, cost-effectiveness and miniaturization. However, the performance of the existing FO-SPR instruments mainly depends on the device surface condition and in particular on the structural aspect of the thin gold (Au) plasmonic film deposited on the FO substrate. In this work, a simple cost-effective colloidal lithography technique (CLT) was adapted and applied for the first time to the micrometer-sized FO substrate, to design end reflection-type FO-SPR sensors with periodic arrays of Au triangularly-shaped nanostructures on the Au mirror FO tip distal end. The nanopatterned FO-SPR sensor tips were afterwards subjected to refractometric measurements in a sucrose dilution series and subsequently compared with their non-patterned counterparts. It was observed that the spectral dips of the nanopatterned FO-SPR sensor tips were shifted towards longer wavelengths after CLT patterning. Moreover, the sensor sensitivity was improved with up to 25% compared to the conventional non-patterned FO-SPR devices. The obtained results represent important steps in the development of a new generation of FO-SPR sensors with improved performance, which can ultimately be used in various applications, ranging from food analysis and environmental monitoring, to health control and medical diagnosis.

Female pattern hair loss.

PubMed

Herskovitz, Ingrid; Tosti, Antonella

2013-10-01

Female pattern hair loss (FPHL) also known as female androgenetic alopecia is a common condition afflicting millions of women that can be cosmetically disrupting. Prompt diagnosis and treatment are essential for obtaining optimal outcome. This review addresses the clinical presentation of female pattern hair loss, its differential diagnosis and treatment modalities. A) Diffuse thinning of the crown region with preservation of the frontal hairline (Ludwig's type) B) The "Christmas tree pattern" where the thinning is wider in the frontal scalp giving the alopecic area a triangular shaped figure resembling a christmas tree. C) Thinning associated with bitemporal recession (Hamilton type). Generally, FPHL is not associated with elevated androgens. Less commonly females with FPHL may have other skin or general signs of hyperandrogenism such as hirsutism, acne, irregular menses, infertility, galactorrhea and insulin resistance. The most common endocrinological abnormality associated with FPHL is polycystic ovarian syndrome (PCOS). The most important diseases to consider in the differential diagnosis of FPHL include Chronic Telogen Effluvium (CTE), Permanent Alopecia after Chemotherapy (PAC), Alopecia Areata Incognito (AAI) and Frontal Fibrosing Alopecia (FFA). This review describes criteria for distinguishing these conditions from FPHL. The only approved treatment for FPHL, which is 2% topical Minoxidil, should be applied at the dosage of 1ml twice day for a minimum period of 12 months. This review will discuss off-label alternative modalities of treatment including 5-alfa reductase inhibitors, antiandrogens, estrogens, prostaglandin analogs, lasers, light treatments and hair transplantation.

Convection Cells in the Atmospheric Boundary Layer

NASA Astrophysics Data System (ADS)

Fodor, Katherine; Mellado, Juan-Pedro

2017-04-01

In dry, shear-free convective boundary layers (CBLs), the turbulent flow of air is known to organise itself on large scales into coherent, cellular patterns, or superstructures, consisting of fast, narrow updraughts and slow, wide downdraughts which together form circulations. Superstructures act as transport mechanisms from the surface to the top of the boundary layer and vice-versa, as opposed to small-scale turbulence, which only modifies conditions locally. This suggests that a thorough investigation into superstructure properties may help us better understand transport across the atmospheric boundary layer as a whole. Whilst their existence has been noted, detailed studies into superstructures in the CBL have been scarce. By applying methods which are known to successfully isolate similar large-scale patterns in turbulent Rayleigh-Bénard convection, we can assess the efficacy of those detection techniques in the CBL. In addition, through non-dimensional analysis, we can systematically compare superstructures in various convective regimes. We use direct numerical simulation of four different cases for intercomparison: Rayleigh-Bénard convection (steady), Rayleigh-Bénard convection with an adiabatic top lid (quasi-steady), a stably-stratified CBL (quasi-steady) and a neutrally-stratified CBL (unsteady). The first two are non-penetrative and the latter two penetrative. We find that although superstructures clearly emerge from the time-mean flow in the non-penetrative cases, they become obscured by temporal averaging in the CBL. This is because a rigid lid acts to direct the flow into counter-rotating circulation cells whose axis of rotation remains stationary, whereas a boundary layer that grows in time and is able to entrain fluid from above causes the circulations to not only grow in vertical extent, but also to move horizontally and merge with neighbouring circulations. Spatial filtering is a useful comparative technique as it can be performed on boundary layers of the same depth, defined from the surface to the height at which the turbulent kinetic energy (TKE) is zero (in non-penetrative cases) or less than 10% of its maximum value (in penetrative cases). We find that with increasing filter width, the contribution of the filtered flow to the total TKE in the middle of the boundary layer decreases much more rapidly in the penetrative cases than in the non-penetrative cases. In particular, around 20-25% of the TKE at this height comes from small-scale turbulence with a length scale less than or equal to 15% of the boundary layer depth in the CBL, whereas in Rayleigh-Bénard convection, it is just 6-7%. This is consistent with visualisations, which show that entrainment creates additional small-scale mixing within the large-scale circulations in the CBL. Without entrainment, large-scale organisation predominates. Neither spatial nor temporal filtering are as successful at extracting superstructures in the penetrative cases as in the non-penetrative cases. Hence, these techniques depend not on the steadiness of the system, but rather on the presence of entrainment. We therefore intend to try other detection techniques, such as proper orthogonal decomposition, in order to make a rigorous assessment of which is most effective for isolating superstructures in all four cases.

Electric field induced self-assembly of monolayers of gold nanoparticles for surface enhanced Raman scattering applications

NASA Astrophysics Data System (ADS)

Das, Suchandra; Musunuri, Naga; Kucheryavy, Pavel; Lockard, Jenny; Fischer, Ian; Singh, Pushpendra; New Jersey Institute of Technology Collaboration; Rutgers University Newark Collaboration

2017-11-01

We present a technique that uses an electric field in the direction normal to the interface for self-assembling monolayers of gold nanoparticles on fluid-liquid interfaces and freezing these monolayers onto the surface of a flexible thin film. The electric field gives rise to dipole-dipole and capillary forces which cause the particles to arrange in a triangular pattern. The technique involves assembling the monolayer on the interface between a UV-curable resin and another fluid by applying an electric field, and then curing the resin by applying UV light. The monolayer becomes embedded on the surface of the solidified resin film. We are using these films for surface enhanced Raman scattering (SERS) applications. Initial measurements indicate improved performance over commercially available SERS substrates.

Thermodynamics of the adsorption of flexible polymers on nanowires

NASA Astrophysics Data System (ADS)

Vogel, Thomas; Gross, Jonathan; Bachmann, Michael

2015-03-01

Generalized-ensemble simulations enable the study of complex adsorption scenarios of a coarse-grained model polymer near an attractive nanostring, representing an ultrathin nanowire. We perform canonical and microcanonical statistical analyses to investigate structural transitions of the polymer and discuss their dependence on the temperature and on model parameters such as effective wire thickness and attraction strength. The result is a complete hyperphase diagram of the polymer phases, whose locations and stability are influenced by the effective material properties of the nanowire and the strength of the thermal fluctuations. Major structural polymer phases in the adsorbed state include compact droplets attached to or wrapping around the wire, and tubelike conformations with triangular pattern that resemble ideal boron nanotubes. The classification of the transitions is performed by microcanonical inflection-point analysis.

Thermodynamics of the adsorption of flexible polymers on nanowires.

PubMed

Vogel, Thomas; Gross, Jonathan; Bachmann, Michael

2015-03-14

Generalized-ensemble simulations enable the study of complex adsorption scenarios of a coarse-grained model polymer near an attractive nanostring, representing an ultrathin nanowire. We perform canonical and microcanonical statistical analyses to investigate structural transitions of the polymer and discuss their dependence on the temperature and on model parameters such as effective wire thickness and attraction strength. The result is a complete hyperphase diagram of the polymer phases, whose locations and stability are influenced by the effective material properties of the nanowire and the strength of the thermal fluctuations. Major structural polymer phases in the adsorbed state include compact droplets attached to or wrapping around the wire, and tubelike conformations with triangular pattern that resemble ideal boron nanotubes. The classification of the transitions is performed by microcanonical inflection-point analysis.

Architected cellular ceramics with tailored stiffness via direct foam writing

NASA Astrophysics Data System (ADS)

Muth, Joseph T.; Dixon, Patrick G.; Woish, Logan; Gibson, Lorna J.; Lewis, Jennifer A.

2017-02-01

Hierarchical cellular structures are ubiquitous in nature because of their low-density, high-specific properties, and multifunctionality. Inspired by these systems, we created lightweight ceramic architectures composed of closed-cell porous struts patterned in the form of hexagonal and triangular honeycombs by direct foam writing. The foam ink contains bubbles stabilized by attractive colloidal particles suspended in an aqueous solution. The printed and sintered ceramic foam honeycombs possess low relative density (˜6%). By tailoring their microstructure and geometry, we created honeycombs with different modes of deformation, exceptional specific stiffness, and stiffness values that span over an order of magnitude. This capability represents an important step toward the scalable fabrication of hierarchical porous materials for applications, including lightweight structures, thermal insulation, tissue scaffolds, catalyst supports, and electrodes.

New species of Parotocinclus (Siluriformes: Loricariidae) from coastal drainages of Rio de Janeiro, southeastern Brazil.

PubMed

Roxo, Fábio F; Melo, Bruno F; Silva, Gabriel S C; Oliveira, Claudio

2017-02-15

A new species of Parotocinclus is described from tributaries of rio São João, an Atlantic coastal river of Rio de Janeiro, southeastern Brazil. The new species is distinguished from its congeners by the possession of a triangular patch of dark pigmentation on the anterior portion of the dorsal-fin base, a fully developed adipose fin, complete exposure of the ventral surface of the pectoral girdle, and a distinctive pigmentation pattern of the caudal fin. The caudal fin has a hyaline background with a large black blotch covering its anterior portion, tapering irregularly through distal portions of the ventral lobe with a hyaline rounded area, and a small patch of dark pigmentation on distal portions of the dorsal lobe.

Architected cellular ceramics with tailored stiffness via direct foam writing

PubMed Central

Muth, Joseph T.; Dixon, Patrick G.; Woish, Logan; Gibson, Lorna J.; Lewis, Jennifer A.

2017-01-01

Hierarchical cellular structures are ubiquitous in nature because of their low-density, high-specific properties, and multifunctionality. Inspired by these systems, we created lightweight ceramic architectures composed of closed-cell porous struts patterned in the form of hexagonal and triangular honeycombs by direct foam writing. The foam ink contains bubbles stabilized by attractive colloidal particles suspended in an aqueous solution. The printed and sintered ceramic foam honeycombs possess low relative density (∼6%). By tailoring their microstructure and geometry, we created honeycombs with different modes of deformation, exceptional specific stiffness, and stiffness values that span over an order of magnitude. This capability represents an important step toward the scalable fabrication of hierarchical porous materials for applications, including lightweight structures, thermal insulation, tissue scaffolds, catalyst supports, and electrodes. PMID:28179570

Ionospheric and Birkeland current distributions inferred from the MAGSAT magnetometer data

NASA Technical Reports Server (NTRS)

Zanetti, L. J.; Potemra, T. A.; Baumjohann, W.

1983-01-01

Ionospheric and field-aligned sheet current density distributions are presently inferred by means of MAGSAT vector magnetometer data, together with an accurate magnetic field model. By comparing Hall current densities inferred from the MAGSAT data and those inferred from simultaneously recorded ground based data acquired by the Scandinavian magnetometer array, it is determined that the former have previously been underestimated due to high damping of magnetic variations with high spatial wave numbers between the ionosphere and the MAGSAT orbit. Among important results of this study is noted the fact that the Birkeland and electrojet current systems are colocated. The analyses have shown a tendency for triangular rather than constant electrojet current distributions as a function of latitude, consistent with the statistical, uniform regions 1 and 2 Birkeland current patterns.

Investigation of the plasma shaping effects on the H-mode pedestal structure using coupled kinetic neoclassical/MHD stability simulations

NASA Astrophysics Data System (ADS)

Pankin, A. Y.; Rafiq, T.; Kritz, A. H.; Park, G. Y.; Snyder, P. B.; Chang, C. S.

2017-06-01

The effects of plasma shaping on the H-mode pedestal structure are investigated. High fidelity kinetic simulations of the neoclassical pedestal dynamics are combined with the magnetohydrodynamic (MHD) stability conditions for triggering edge localized mode (ELM) instabilities that limit the pedestal width and height in H-mode plasmas. The neoclassical kinetic XGC0 code [Chang et al., Phys. Plasmas 11, 2649 (2004)] is used in carrying out a scan over plasma elongation and triangularity. As plasma profiles evolve, the MHD stability limits of these profiles are analyzed with the ideal MHD ELITE code [Snyder et al., Phys. Plasmas 9, 2037 (2002)]. Simulations with the XGC0 code, which includes coupled ion-electron dynamics, yield predictions for both ion and electron pedestal profiles. The differences in the predicted H-mode pedestal width and height for the DIII-D discharges with different elongation and triangularities are discussed. For the discharges with higher elongation, it is found that the gradients of the plasma profiles in the H-mode pedestal reach semi-steady states. In these simulations, the pedestal slowly continues to evolve to higher pedestal pressures and bootstrap currents until the peeling-ballooning stability conditions are satisfied. The discharges with lower elongation do not reach the semi-steady state, and ELM crashes are triggered at earlier times. The plasma elongation is found to have a stronger stabilizing effect than the plasma triangularity. For the discharges with lower elongation and lower triangularity, the ELM frequency is large, and the H-mode pedestal evolves rapidly. It is found that the temperature of neutrals in the scrape-off-layer (SOL) region can affect the dynamics of the H-mode pedestal buildup. However, the final pedestal profiles are nearly independent of the neutral temperature. The elongation and triangularity affect the pedestal widths of plasma density and electron temperature profiles differently. This provides a new mechanism of controlling the pedestal bootstrap current and the pedestal stability.

Triangular Resection of the Upper Lateral Cartilage for Middle Vault Deviation.

PubMed

Ryu, Gwanghui; Seo, Min Young; Lee, Kyung Eun; Hong, Sang Duk; Chung, Seung-Kyu; Dhong, Hun-Jong; Kim, Hyo Yeol

2018-06-02

Middle vault deviation has a significant effect on the aesthetic and functional aspects of the nose, and its management continues to be a challenge. Spreader graft and its modification techniques have been focused, but there has been scarce consideration for removing surplus portion and balancing the upper lateral cartilage (ULC). This study aimed to report the newly invented triangular-shaped resection technique ("triangular resection") of the ULC and to evaluate its efficacy for correcting middle vault deviation. A retrospective study included 17 consecutive patients who presented with middle vault deviation and underwent septorhinoplasty by using triangular resection at a tertiary academic hospital from February 2014 and March 2016. Their outcomes were evaluated pre- and postoperatively including medical photographs, acoustic rhinometry and subjective nasal obstruction using a 7-point Likert scale. The immediate outcomes were evaluated around 1 month after surgery, and long-term outcomes were available in 12 patients; the mean follow-up period was 9.1 months. Nasal tip deviation angle was reduced from 5.66º to 2.37º immediately (P<0.001). Middle vault deviation also improved from 169.50º to 177.24º (P<0.001). Long-term results were 2.49º (P=0.015) for nasal tip deviation and 178.68º (P=0.002) for middle vault deviation. The aesthetic outcome involved a complete correction in eight patients (47.1%), a minimally visible deviation in seven patients (41.2%) and a remaining residual deviation in two patients (11.8%). Pre- and postoperative minimal cross-sectional areas (summation of the right and left sides) were 0.86 and 1.07, respectively (P=0.021). Fifteen patients answered about their nasal obstruction symptoms and the median symptom score had alleviated from 6.0 to 3.0 (P=0.004). Triangular resection of the ULC is a simple and effective method for correcting middle vault deviation and balancing the ULCs without complications as internal nasal valve narrowing.

Investigation of the plasma shaping effects on the H-mode pedestal structure using coupled kinetic neoclassical/MHD stability simulations

DOE PAGES

Pankin, A. Y.; Rafiq, T.; Kritz, A. H.; ...

2017-06-08

The effects of plasma shaping on the H-mode pedestal structure are investigated. High fidelity kinetic simulations of the neoclassical pedestal dynamics are combined with the magnetohydrodynamic (MHD) stability conditions for triggering edge localized mode (ELM) instabilities that limit the pedestal width and height in H-mode plasmas. We use the neoclassical kinetic XGC0 code [Chang et al., Phys. Plasmas 11, 2649 (2004)] to carry out a scan over plasma elongation and triangularity. As plasma profiles evolve, the MHD stability limits of these profiles are analyzed with the ideal MHD ELITE code [Snyder et al., Phys. Plasmas 9, 2037 (2002)]. In simulationsmore » with the XGC0 code, which includes coupled ion-electron dynamics, yield predictions for both ion and electron pedestal profiles. The differences in the predicted H-mode pedestal width and height for the DIII-D discharges with different elongation and triangularities are discussed. For the discharges with higher elongation, it is found that the gradients of the plasma profiles in the H-mode pedestal reach semi-steady states. In these simulations, the pedestal slowly continues to evolve to higher pedestal pressures and bootstrap currents until the peeling-ballooning stability conditions are satisfied. The discharges with lower elongation do not reach the semi-steady state, and ELM crashes are triggered at earlier times. The plasma elongation is found to have a stronger stabilizing effect than the plasma triangularity. For the discharges with lower elongation and lower triangularity, the ELM frequency is large, and the H-mode pedestal evolves rapidly. It is found that the temperature of neutrals in the scrape-off-layer (SOL) region can affect the dynamics of the H-mode pedestal buildup. But the final pedestal profiles are nearly independent of the neutral temperature. The elongation and triangularity affect the pedestal widths of plasma density and electron temperature profiles differently. This provides a new mechanism of controlling the pedestal bootstrap current and the pedestal stability.« less

Investigation of the plasma shaping effects on the H-mode pedestal structure using coupled kinetic neoclassical/MHD stability simulations

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

Pankin, A. Y.; Rafiq, T.; Kritz, A. H.

The effects of plasma shaping on the H-mode pedestal structure are investigated. High fidelity kinetic simulations of the neoclassical pedestal dynamics are combined with the magnetohydrodynamic (MHD) stability conditions for triggering edge localized mode (ELM) instabilities that limit the pedestal width and height in H-mode plasmas. We use the neoclassical kinetic XGC0 code [Chang et al., Phys. Plasmas 11, 2649 (2004)] to carry out a scan over plasma elongation and triangularity. As plasma profiles evolve, the MHD stability limits of these profiles are analyzed with the ideal MHD ELITE code [Snyder et al., Phys. Plasmas 9, 2037 (2002)]. In simulationsmore » with the XGC0 code, which includes coupled ion-electron dynamics, yield predictions for both ion and electron pedestal profiles. The differences in the predicted H-mode pedestal width and height for the DIII-D discharges with different elongation and triangularities are discussed. For the discharges with higher elongation, it is found that the gradients of the plasma profiles in the H-mode pedestal reach semi-steady states. In these simulations, the pedestal slowly continues to evolve to higher pedestal pressures and bootstrap currents until the peeling-ballooning stability conditions are satisfied. The discharges with lower elongation do not reach the semi-steady state, and ELM crashes are triggered at earlier times. The plasma elongation is found to have a stronger stabilizing effect than the plasma triangularity. For the discharges with lower elongation and lower triangularity, the ELM frequency is large, and the H-mode pedestal evolves rapidly. It is found that the temperature of neutrals in the scrape-off-layer (SOL) region can affect the dynamics of the H-mode pedestal buildup. But the final pedestal profiles are nearly independent of the neutral temperature. The elongation and triangularity affect the pedestal widths of plasma density and electron temperature profiles differently. This provides a new mechanism of controlling the pedestal bootstrap current and the pedestal stability.« less

Manipulation of fluids in three-dimensional porous photonic structures with patterned surface properties

DOEpatents

Aizenberg, Joanna; Burgess, Ian B.; Mishchenko, Lidiya; Hatton, Benjamin; Loncar, Marko

2016-03-08

A three-dimensional porous photonic structure, whose internal pore surfaces can be provided with desired surface properties in a spatially selective manner with arbitrary patterns, and methods for making the same are described. When exposed to a fluid (e.g., via immersion or wicking), the fluid can selectively penetrate the regions of the structure with compatible surface properties. Broad applications, for example in security, encryption and document authentication, as well as in areas such as simple microfluidics and diagnostics, are anticipated.

Manipulation of fluids in three-dimensional porous photonic structures with patterned surface properties

DOEpatents

Aizenberg, Joanna; Burgess, Ian; Mishchenko, Lidiya; Hatton, Benjamin; Loncar, Marko

2017-12-26

A three-dimensional porous photonic structure, whose internal pore surfaces can be provided with desired surface properties in a spatially selective manner with arbitrary patterns, and methods for making the same are described. When exposed to a fluid (e.g., via immersion or wicking), the fluid can selectively penetrate the regions of the structure with compatible surface properties. Broad applications, for example in security, encryption and document authentication, as well as in areas such as simple microfluidics and diagnostics, are anticipated.

Laser patterning of platinum electrodes for safe neurostimulation

NASA Astrophysics Data System (ADS)

Green, R. A.; Matteucci, P. B.; Dodds, C. W. D.; Palmer, J.; Dueck, W. F.; Hassarati, R. T.; Byrnes-Preston, P. J.; Lovell, N. H.; Suaning, G. J.

2014-10-01

Objective. Laser surface modification of platinum (Pt) electrodes was investigated for use in neuroprosthetics. Surface modification was applied to increase the surface area of the electrode and improve its ability to transfer charge within safe electrochemical stimulation limits. Approach. Electrode arrays were laser micromachined to produce Pt electrodes with smooth surfaces, which were then modified with four laser patterning techniques to produce surface structures which were nanosecond patterned, square profile, triangular profile and roughened on the micron scale through structured laser interference patterning (SLIP). Improvements in charge transfer were shown through electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and biphasic stimulation at clinically relevant levels. A new method was investigated and validated which enabled the assessment of in vivo electrochemically safe charge injection limits. Main results. All of the modified surfaces provided electrical advantage over the smooth Pt. The SLIP surface provided the greatest benefit both in vitro and in vivo, and this surface was the only type which had injection limits above the threshold for neural stimulation, at a level shown to produce a response in the feline visual cortex when using an electrode array implanted in the suprachoroidal space of the eye. This surface was found to be stable when stimulated with more than 150 million clinically relevant pulses in physiological saline. Significance. Critical to the assessment of implant devices is accurate determination of safe usage limits in an in vivo environment. Laser patterning, in particular SLIP, is a superior technique for improving the performance of implant electrodes without altering the interfacial electrode chemistry through coating. Future work will require chronic in vivo assessment of these electrode patterns.

The role of imaging in diagnosing diseases of the distal radioulnar joint, triangular fibrocartilage complex, and distal ulna.

PubMed

Squires, Judy H; England, Eric; Mehta, Kaushal; Wissman, Robert D

2014-07-01

The purpose of this article is to review the anatomy, biomechanics, and multimodality imaging findings of common and uncommon distal radioulnar joint (DRUJ), triangular fibrocartilage complex, and distal ulna abnormalities. The DRUJ is a common site for acute and chronic injuries and is frequently imaged to evaluate chronic wrist pain, forearm dysfunction, and traumatic forearm injury. Given the complex anatomy of the wrist, the radiologist plays a vital role in the diagnosis of wrist pain and dysfunction.

Equivalent formulae of stress Green's functions for a constant slip rate on a triangular fault

NASA Astrophysics Data System (ADS)

Feng, Xi; Zhang, Haiming

2017-06-01

We present an equivalent form of the expressions first obtained by Tada (Geophys J Int 164:653-669, 2006. doi: 10.1111/j.1365-246X.2006.03868.x), which represents the transient stress response of an infinite, homogeneous and isotropic medium to a constant slip rate on a triangular fault that continues perpetually after the slip onset. Our results are simpler than Tada's, and the corresponding codes have a higher running speed.

Electromagnetic field scattering by a triangular aperture.

PubMed

Harrison, R E; Hyman, E

1979-03-15

The multiple Laplace transform has been applied to analysis and computation of scattering by a double triangular aperture. Results are obtained which match far-field intensity distributions observed in experiments. Arbitrary polarization components, as well as in-phase and quadrature-phase components, may be determined, in the transform domain, as a continuous function of distance from near to far-field for any orientation, aperture, and transformable waveform. Numerical results are obtained by application of numerical multiple inversions of the fully transformed solution.

a Triangular Deformation of the Two-Dimensional POINCARÉ Algebra

NASA Astrophysics Data System (ADS)

Khorrami, M.; Shariati, A.; Abolhassani, M. R.; Aghamohammadi, A.

Contracting the h-deformation of SL(2, ℝ), we construct a new deformation of two-dimensional Poincaré's algebra, the algebra of functions on its group and its differential structure. It is seen that these dual Hopf algebras are isomorphic to each other. It is also shown that the Hopf algebra is triangular, and its universal R-matrix is also constructed explicitly. We then find a deformation map for the universal enveloping algebra, and at the end, give the deformed mass shells and Lorentz transformation.

Shape and edge dependent electronic and magnetic properties of silicene nano-flakes

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

Mohan, Brij, E-mail: brijmohanhpu@yahoo.com; Pooja,; Ahluwalia, P. K.

2015-06-24

We performed first-principle study of the geometric, electronic and magnetic properties of arm-chair and zigzag edge silicene nano-flakes of triangular and hexagonal shapes. Electronic properties of silicene nano-flakes show strong dependence on their edge structure and shape. The considered nanostructures shows energy gap ranging ∼ 0.4 – 1.0 eV. Zigzag edged triangular nano-flake is magnetic and semiconducting in nature with 4.0 µ{sub B} magnetic moment and ∼ 0.4 eV energy gap.

Factors Affecting Mobile Banking Adoption in the United States

ERIC Educational Resources Information Center

Engwanda, Michel Ndongola

2014-01-01

Mobile banking (m-banking) allows consumers to conduct financial transactions without temporal and spatial constraints through Internet-enabled mobile devices such as smartphones. The adoption patterns are of particular research interest because m-banking penetration has been relatively low even though smartphones are the most dominant forms of…

Bursting at the Seams: Rippled Monolayer Bismuth on NbSe 2

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

Fang, Alan; Adamo, Carolina; Jia, Shuang

Bismuth, one of the heaviest semimetals in nature, ignited the interest of the materials-physics community for its potential impact on topological quantum-material systems that utilize its strong spin-orbit coupling (SOC) and unique orbital hybridization. In particular, recent theoretical predictions of unique topological and superconducting properties of thin bismuth films and interfaces prompted intense research on the growth of sub- to a few monolayers of bismuth on different substrates. Similar to bulk rhombohedral bismuth, the initial growth of bismuth films on most substrates results in buckled bilayers that either grow in the (111) or (110) directions, with a lattice constant closemore » to that of bulk Bi. By contrast, in this paper we show a new growth pattern for bismuth monolayers on NbSe 2. We find that the initial growth of Bi can form a strongly bonded commensurate layer, resulting in a compressively strained two-dimensional triangular lattice. A unique pattern of 1D ripples and domain walls is observed. The single layer of bismuth also introduces strong marks on the electronic properties at the surface.« less

A programmable nanoreplica molding for the fabrication of nanophotonic devices.

PubMed

Liu, Longju; Zhang, Jingxiang; Badshah, Mohsin Ali; Dong, Liang; Li, Jingjing; Kim, Seok-min; Lu, Meng

2016-03-01

The ability to fabricate periodic structures with sub-wavelength features has a great potential for impact on integrated optics, optical sensors, and photovoltaic devices. Here, we report a programmable nanoreplica molding process to fabricate a variety of sub-micrometer periodic patterns using a single mold. The process utilizes a stretchable mold to produce the desired periodic structure in a photopolymer on glass or plastic substrates. During the replica molding process, a uniaxial force is applied to the mold and results in changes of the periodic structure, which resides on the surface of the mold. Direction and magnitude of the force determine the array geometry, including the lattice constant and arrangement. By stretching the mold, 2D arrays with square, rectangular, and triangular lattice structures can be fabricated. As one example, we present a plasmonic crystal device with surface plasmon resonances determined by the force applied during molding. In addition, photonic crystal slabs with different array patterns are fabricated and characterized. This unique process offers the capability of generating various periodic nanostructures rapidly and inexpensively.

Research on the Perforating Algorithm Based on STL Files

NASA Astrophysics Data System (ADS)

Yuchuan, Han; Xianfeng, Zhu; Yunrui, Bai; Zhiwen, Wu

2018-04-01

In the process of making medical personalized external fixation brace, the 3D data file should be perforated to increase the air permeability and reduce the weight. In this paper, a perforating algorithm for 3D STL file is proposed, which can perforate holes, hollow characters and engrave decorative patterns on STL files. The perforating process is composed of three steps. Firstly, make the imaginary space surface intersect with the STL model, and reconstruct triangles at the intersection. Secondly, delete the triangular facets inside the space surface and make a hole on the STL model. Thirdly, triangulate the inner surface of the hole, and thus realize the perforating. Choose the simple space equations such as cylindrical and rectangular prism equations as perforating equations can perforate round holes and rectangular holes. Through the combination of different holes, lettering, perforating decorative patterns and other perforated results can be accomplished. At last, an external fixation brace and an individual pen container were perforated holes using the algorithm, and the expected results were reached, which proved the algorithm is feasible.

A programmable nanoreplica molding for the fabrication of nanophotonic devices

PubMed Central

Liu, Longju; Zhang, Jingxiang; Badshah, Mohsin Ali; Dong, Liang; Li, Jingjing; Kim, Seok-min; Lu, Meng

2016-01-01

The ability to fabricate periodic structures with sub-wavelength features has a great potential for impact on integrated optics, optical sensors, and photovoltaic devices. Here, we report a programmable nanoreplica molding process to fabricate a variety of sub-micrometer periodic patterns using a single mold. The process utilizes a stretchable mold to produce the desired periodic structure in a photopolymer on glass or plastic substrates. During the replica molding process, a uniaxial force is applied to the mold and results in changes of the periodic structure, which resides on the surface of the mold. Direction and magnitude of the force determine the array geometry, including the lattice constant and arrangement. By stretching the mold, 2D arrays with square, rectangular, and triangular lattice structures can be fabricated. As one example, we present a plasmonic crystal device with surface plasmon resonances determined by the force applied during molding. In addition, photonic crystal slabs with different array patterns are fabricated and characterized. This unique process offers the capability of generating various periodic nanostructures rapidly and inexpensively. PMID:26925828

Bursting at the Seams: Rippled Monolayer Bismuth on NbSe 2

DOE PAGES

Fang, Alan; Adamo, Carolina; Jia, Shuang; ...

2018-04-13

Bismuth, one of the heaviest semimetals in nature, ignited the interest of the materials-physics community for its potential impact on topological quantum-material systems that utilize its strong spin-orbit coupling (SOC) and unique orbital hybridization. In particular, recent theoretical predictions of unique topological and superconducting properties of thin bismuth films and interfaces prompted intense research on the growth of sub- to a few monolayers of bismuth on different substrates. Similar to bulk rhombohedral bismuth, the initial growth of bismuth films on most substrates results in buckled bilayers that either grow in the (111) or (110) directions, with a lattice constant closemore » to that of bulk Bi. By contrast, in this paper we show a new growth pattern for bismuth monolayers on NbSe 2. We find that the initial growth of Bi can form a strongly bonded commensurate layer, resulting in a compressively strained two-dimensional triangular lattice. A unique pattern of 1D ripples and domain walls is observed. The single layer of bismuth also introduces strong marks on the electronic properties at the surface.« less

"Contagious Love": A Qualitative Study of the Couple Relationships of Ten AIDS Carriers

PubMed Central

Doron, Hadas; Teichner, Noa; Grey, Adi; Goldstein, Yehudit

2008-01-01

The qualitative study in this article portrays the couple relationship among AIDS carriers, based on Sternberg's triangular love theory (involving domains of intimacy, passion and commitment). The central study hypothesis is that certain components of the Sternberg model will be more significant than others among the AIDS carrier population. The study was conducted on ten AIDS carriers aged 21-37 who had experienced a couple relationship. Six men and four women participated; most of them were in a romantic couple relationship of homosexual orientation. The interviewees answered a questionnaire that included the three domains-- intimacy, passion and commitment--in the personal interview technique. The interview focused on interviewee's attitude towards his/her relationship with a partner, as he/she understood it. The findings of the study focus on relevant content that was gathered from the interviews and these portray a limited view of couple patterns in the world of AIDS carriers. The study reveals two major findings regarding the carrier's desires: On the one hand, the carrier describes a powerful need for a stable, permanent relationship--from the diagnosis of AIDS and throughout the subsequent years. On the other hand, the carrier also expresses powerful sexual desires that are not necessarily limited to a permanent partner. Thus passion is the dominant among the three domains. The intimacy domain is mainly affected by disclosure of the disease and the joint coping that follows. The findings are discussed in the context of the romantic internalized model theory and Sternberg's triangular love theory. PMID:18923698

Functional networks of motor inhibition in conversion disorder patients and feigning subjects.

PubMed

Hassa, Thomas; de Jel, Esther; Tuescher, Oliver; Schmidt, Roger; Schoenfeld, Mircea Ariel

2016-01-01

The neural correlates of motor inhibition leading to paresis in conversion disorder are not well known. The key question is whether they are different of those of normal subjects feigning the symptoms. Thirteen conversion disorder patients with hemiparesis and twelve healthy controls were investigated using functional magnetic resonance tomography under conditions of passive motor stimulation of the paretic/feigned paretic and the non-paretic hand. Healthy controls were also investigated in a non-feigning condition. During passive movement of the affected right hand conversion disorder patients exhibited activations in the bilateral triangular part of the inferior frontal gyri (IFG), with a left side dominance compared to controls in non-feigning condition. Feigning controls revealed for the same condition a weak unilateral activation in the right triangular part of IFG and an activity decrease in frontal midline areas, which couldn't be observed in patients. The results suggest that motor inhibition in conversion disorder patients is mediated by the IFG that was also involved in inhibition processes in normal subjects. The activity pattern in feigning controls resembled that of conversion disorder patients but with a clear difference in the medial prefrontal cortex. Healthy controls showed decreased activity in this region during feigning compared to non-feigning conditions suggesting a reduced sense of self-agency during feigning. Remarkably, no activity differences could be observed in medial prefrontal cortex for patients vs healthy controls in feigning or non-feigning conditions suggesting self-agency related activity in patients to be in between those of non-feigning and feigning healthy subjects.

Emergent properties of magnetic materials

NASA Astrophysics Data System (ADS)

Ratcliff, William Davis, II

In Tolstoy's War and Peace, history is presented as a tapestry spun from the daily interactions of large numbers of individuals. Even if one understands individuals, it is very difficult to predict history. Similarly, the interactions of large numbers of electrons give rise to properties that one would not initially guess from their microscopic interactions. During the course of my dissertation, I have explored emergent phenomena in a number of contexts. In ZnCr2O4, geometric frustration gives rise to a plethora of equivalent ground states. From these, a lower dimensional set of collinear spins on hexagons are selected to form the building blocks of the lattice. In MgTi2O4, quantum spins dimerize and form a unique chiral ordering pattern on the spinel lattice. Descending into two dimensions, differences in size and charge give rise to an ordering between triangular layers of magnetic and nonmagnetic ions. This triangular lattice allows for the possibility of observing the RVB spin liquid state, or perhaps a valence bond crystal and initial measurements are promising. Also, on the spinel lattice, ionic ordering gives rise to one dimensional chains with their own interesting physics. Finally, in the SrCoxTi1-x O3, system we find that upon reduction, tiny clusters of Co metal precipitate out and chemical inhomogeneity on the microscale may determine much of the physics. This has relevance to a number of recent claims of room temperature ferromagnism in dilute magnetic systems. In all of these systems, complex behavior emerges from well understood microscopic behavior. For me, this is the fascination of strongly correlated electronic systems.

The role of eggshell and underlying vitelline membrane for normal pattern formation in the early C. elegans embryo.

PubMed

Schierenberg, Einhard; Junkersdorf, Bernd

1992-12-01

The embryo of the nematode Caenorhabditis elegans is surrounded by an inconspicuous inner vitelline membrane and a prominent outer chitinous eggshell proper. We demonstrate that the complete removal of the chitinous eggshell does not interfere with successful development to yield a normal worm. The same result can be obtained when the vitelline membrane is penetrated with laser microbeam irradiation of only the eggshell proper, gently enough to permit its resealing after a while. However, when large holes are made into the eggshell the concomitantly penetrated vitelline membrane does not reseal. While early development is quite normal under these conditions, gastrulation is defective in that gut precursor cells do not migrate in properly, eventually leading to embryonic arrest. This suggests a crucial role for pattern formation of the "micro-environment" around the embryo preserved by the intact vitelline membrane. Removing both eggshell and vitelline membrane results in a string-like arrangement of founder cells and subsequent grossly abnormal cell patterns. Our experiments support the idea that the prominent eggshell proper just functions as a mechanical protection while the thin vitelline membrane directly or indirectly serves as a necessary control element affecting the positions of cells which to begin with are determined by the orientation of the cleavage spindle.

A Ballistics Examination of Firearm Injuries Involving Breast Implants.

PubMed

Pannucci, Christopher J; Cyr, Adam J; Moores, Neal G; Young, Jason B; Szegedi, Martin

2018-03-01

This ballistics study examines whether saline breast implants can decrease tissue penetration in firearm injuries. We hypothesize that the fluid column within a saline breast implant can alter bullet velocity and/or bullet pattern of mushrooming. The two experimental groups included saline implants with 7.4 cm projection and a no implant group. The experimental design allowed the bullet to pass-through an implant and into ballistics gel (n = 10) or into ballistics gel without passage through an implant (n = 11). Shots that passed through an implant had 20.6% decreased penetration distance when compared to shots that did not pass-through an implant; this difference was statistically significant (31.9 cm vs. 40.2 cm, p < 0.001). Implant group bullets mushroomed prior to gel entry, but the no implant group mushroomed within the gel. Bullet passage through a saline breast implant results in direct bullet velocity reduction and earlier bullet mushrooming; this causes significantly decreased ballistics gel penetration. © 2017 American Academy of Forensic Sciences.

Nail injury to the brain obfuscated by a fall from height - homicide or suicide? a case report.

PubMed

Aggrawal, Anil; Pradhan, Monisha; Sreenivas, M

2015-01-01

Penetrating head injuries caused by unconventional objects such as a nail generate speculation and doubt regarding the manner of infliction. We report a case of a 24-year-old woman alleged to have committed suicide by a fall from height. Autopsy revealed an unprecedented penetrating intracranial injury caused by a nail over the right temporal region, confounding the manner of death. The underlying intersecting pattern of fractures determined the chronological sequence of events. In this paper, we discuss the manner, incidence and pathology of nail injuries to the brain. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Quantifying bushfire penetration into urban areas in Australia

NASA Astrophysics Data System (ADS)

Chen, Keping; McAneney, John

2004-06-01

The extent and trajectory of bushfire penetration at the bushland-urban interface are quantified using data from major historical fires in Australia. We find that the maximum distance at which homes are destroyed is typically less than 700 m. The probability of home destruction emerges as a simple linear and decreasing function of distance from the bushland-urban boundary but with a variable slope that presumably depends upon fire regime and human intervention. The collective data suggest that the probability of home destruction at the forest edge is around 60%. Spatial patterns of destroyed homes display significant neighbourhood clustering. Our results provide revealing spatial evidence for estimating fire risk to properties and suggest an ember-attack model.

Polarization-independent triangular-groove fused-silica gratings with high efficiency at a wavelength of 1550 nm

NASA Astrophysics Data System (ADS)

Cao, Hongchao; Zhou, Changhe; Feng, Jijun; Lv, Peng; Ma, Jianyong

2010-11-01

We describe polarization-independent triangular-groove fused-silica gratings illuminated by incident lights in the C + L bands as (de)multiplexers for dense wavelength division multiplexing (DWDM) application. The physical mechanisms of the grating can be shown clearly by using the simplified modal method with consideration of the corresponding accumulated average phase difference of two excited propagating grating modes, which illustrates that the grating structure depends mainly on the ratio of the average effective indices difference to the incident wavelength. Exact grating profile is optimized by using the rigorous coupled-wave analysis (RCWA). With the optimized grating parameters, the grating exhibits diffraction efficiencies of greater than 90% under TE- and TM-polarized incident lights for 101 nm spectral bandwidths (1500-1601 nm) and it can reach an efficiency of more than 99% for both polarizations at a wavelength of 1550 nm. Without loss of metal absorption, coating of dielectric film layers, the designed triangular-groove fused-silica grating should be of great interest for DWDM application.

Palmar reconstruction of the triangular fibrocartilage complex for instability of the distal radioulnar joint: a biomechanical study.

PubMed

Kataoka, T; Moritomo, H; Omokawa, S; Iida, A; Wada, T; Aoki, M

2013-06-01

We developed a new triangular fibrocartilage complex reconstruction technique for distal radioulnar joint instability in which the palmar portion of the triangular fibrocartilage complex was predominantly reconstructed, and evaluated whether such reconstruction can restore stability of the distal radioulnar joint in seven fresh cadaver upper extremities. Distal radioulnar joint instability was induced by cutting all soft-tissue stabilizers around the distal ulna. Using a palmar approach, a palmaris longus tendon graft was sutured to the remnant of the palmar radioulnar and ulnocarpal ligaments. The graft was then passed through a bone tunnel created at the fovea and was sutured. Loads were applied to the radius, and dorsopalmar displacements of the radius relative to the ulna were measured using an electromagnetic tracking device in neutral rotation, 60° supination and 60° pronation. We compared the dorsopalmar displacements before sectioning, before reconstruction and after reconstruction. Dorsopalmar instability produced by sectioning significantly improved in all forearm positions after reconstruction.

In-plane crashworthiness of bio-inspired hierarchical honeycombs

DOE PAGES

Yin, Hanfeng; Huang, Xiaofei; Scarpa, Fabrizio; ...

2018-03-13

Biological tissues like bone, wood, and sponge possess hierarchical cellular topologies, which are lightweight and feature an excellent energy absorption capability. Here we present a system of bio-inspired hierarchical honeycomb structures based on hexagonal, Kagome, and triangular tessellations. The hierarchical designs and a reference regular honeycomb configuration are subjected to simulated in-plane impact using the nonlinear finite element code LS-DYNA. The numerical simulation results show that the triangular hierarchical honeycomb provides the best performance compared to the other two hierarchical honeycombs, and features more than twice the energy absorbed by the regular honeycomb under similar loading conditions. We also proposemore » a parametric study correlating the microstructure parameters (hierarchical length ratio r and the number of sub cells N) to the energy absorption capacity of these hierarchical honeycombs. The triangular hierarchical honeycomb with N = 2 and r = 1/8 shows the highest energy absorption capacity among all the investigated cases, and this configuration could be employed as a benchmark for the design of future safety protective systems.« less

Dirac fermions and pseudomagnetic fields in two-dimensional electron gases with triangular antidot lattices

NASA Astrophysics Data System (ADS)

Li, Yun-Mei; Zhou, Xiaoying; Zhang, Yan-Yang; Zhang, Dong; Chang, Kai

2017-07-01

We investigate theoretically the electronic properties of two-dimensional electron gases (2DEGs) with regular and distorted triangular antidot lattices. We show that the triangular antidot lattices embedded in 2DEGs behave like artificial graphene and host Dirac fermions. By introducing the Wannier representation, we obtain a tight-binding Hamiltonian including the second-nearest-neighboring hopping, which agrees well with the numerically exact solutions. Based on the tight-binding model, we find that spatially nonuniform distortions of the antidot lattices strongly modify the electronic structures, generate pseudomagnetic fields and the well-defined Landau levels. In contrast to graphene, we can design the nonuniform distortions to generate various configurations of pseudomagnetic fields. We show that the snake orbital states arise by designing the ±B pseudomagnetic field configuration. We find that the disorders of antidot lattices during fabrication would not affect the basic feature of the Dirac electrons, but they lead to a reduction in conductance in strong disorder cases.

Triangular covariance factorizations for. Ph.D. Thesis. - Calif. Univ.

NASA Technical Reports Server (NTRS)

Thornton, C. L.

1976-01-01

An improved computational form of the discrete Kalman filter is derived using an upper triangular factorization of the error covariance matrix. The covariance P is factored such that P = UDUT where U is unit upper triangular and D is diagonal. Recursions are developed for propagating the U-D covariance factors together with the corresponding state estimate. The resulting algorithm, referred to as the U-D filter, combines the superior numerical precision of square root filtering techniques with an efficiency comparable to that of Kalman's original formula. Moreover, this method is easily implemented and involves no more computer storage than the Kalman algorithm. These characteristics make the U-D method an attractive realtime filtering technique. A new covariance error analysis technique is obtained from an extension of the U-D filter equations. This evaluation method is flexible and efficient and may provide significantly improved numerical results. Cost comparisons show that for a large class of problems the U-D evaluation algorithm is noticeably less expensive than conventional error analysis methods.

Evolution of silver/gold triangular nanoframes from prismatic silver/gold core/shell nanostructures and their SERS properties

NASA Astrophysics Data System (ADS)

Parthiban, P.; Sakar, M.; Balakumar, S.

2013-02-01

We report the evolution of Ag/Au triangular nanoframes from nano core/shell of Ag/Au and their surface enhanced Raman scattering (SERS) properties. The Ag/Au prismatic core/shell nanostructures were synthesized using chemical reduction method. It was observed that, on the addition of excess gold chloride (HAuCl4) solution, the morphology of nano core/shell was changed to alloy like triangular nanoframes. Accordingly, a shift was found towards higher wavelengths in the UV-Visible absorption peaks of Ag/Au nanoframes compare to Ag/Au nano core/shell. Consequently, the SERS effect of these Ag/Au anisotropic nanostructures were studied on methylene blue. The Ag/Au alloy like prismatic nanoframes showed improved SERS effect than that of prismatic core/shell nanostructures. The experimental findings were revealed that the improved SERS effect could be resulted from the enhanced surface plasmon resonance (SPR) due to the alloy like construction of Ag/Au system.

One-pot synthesis of triangular Ag nanoplates with tunable edge length.

PubMed

Zhang, Yulan; Yang, Ping; Zhang, Lipeng

2012-11-01

Triangular Ag nanoplates were prepared via a one-pot synthesis method by using citrate and poly (vinyl pyrolidone) (PVP). The edge length of the nanoplates was changed from 30 nm to 100 nm with increasing the concentration of PVP and the amount of sodium borohydride in aqueous solutions during preparation. The molar ratio of PVP to Ag nitrate affected the morphologies of the nanoplates. PVP plays an important role for determining the final morphologies and edge length of resulting nanoplates because the amount of PVP affected the viscosity of solutions. The viscosity of solutions kinetically controlled the nucleation and growth of Ag nanoplates. Furthermore, Ag nanoplates were not created in the case of without PVP. After adding sodium chloride, irregular Ag nanoparticles (NPs) instead of nanoplates were fabricated because of a Cl-/O2 etching process. Stacking fault was a key for the growth of triangular nanostructures. Reaction temperature and aging time also affected the formation of Ag nanoplates.

Improvements in sparse matrix operations of NASTRAN

NASA Technical Reports Server (NTRS)

Harano, S.

1980-01-01

A "nontransmit" packing routine was added to NASTRAN to allow matrix data to be refered to directly from the input/output buffer. Use of the packing routine permits various routines for matrix handling to perform a direct reference to the input/output buffer if data addresses have once been received. The packing routine offers a buffer by buffer backspace feature for efficient backspacing in sequential access. Unlike a conventional backspacing that needs twice back record for a single read of one record (one column), this feature omits overlapping of READ operation and back record. It eliminates the necessity of writing, in decomposition of a symmetric matrix, of a portion of the matrix to its upper triangular matrix from the last to the first columns of the symmetric matrix, thus saving time for generating the upper triangular matrix. Only a lower triangular matrix must be written onto the secondary storage device, bringing 10 to 30% reduction in use of the disk space of the storage device.

Hierarchical concave layered triangular PtCu alloy nanostructures: rational integration of dendritic nanostructures for efficient formic acid electrooxidation.

PubMed

Wu, Fengxia; Lai, Jianping; Zhang, Ling; Niu, Wenxin; Lou, Baohua; Luque, Rafael; Xu, Guobao

2018-05-08

The rational construction of multi-dimensional layered noble metal nanostructures is a great challenge since noble metals are not layer-structured materials. Herein, we report a one-pot hydrothermal synthetic method for PtCu hierarchical concave layered triangular (HCLT) nanostructures using dl-carnitine, KI, poly(vinylpyrrolidone), CuCl2, and H2PtCl6. The PtCu HCLT nanostructure is comprised of multilayered triangular dendrites. Its layer number is tunable by changing dl-carnitine concentrations, and the concavity/convexity of the PtCu triangle nanostructures is tunable by changing the H2PtCl6/CuCl2 ratio or KI concentrations. Hierarchical trigonal bipyramid nanoframes are also obtained under certain conditions. Because of its advantageous nanostructure and bimetallic synergetic effect, the obtained PtCu HCLT nanostructure exhibits enhanced electrocatalytic activity and prolonged stability to formic acid oxidation compared to commercial Pt black, Pd/C and some other nanostructures.

In-plane crashworthiness of bio-inspired hierarchical honeycombs

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

Yin, Hanfeng; Huang, Xiaofei; Scarpa, Fabrizio

Biological tissues like bone, wood, and sponge possess hierarchical cellular topologies, which are lightweight and feature an excellent energy absorption capability. Here we present a system of bio-inspired hierarchical honeycomb structures based on hexagonal, Kagome, and triangular tessellations. The hierarchical designs and a reference regular honeycomb configuration are subjected to simulated in-plane impact using the nonlinear finite element code LS-DYNA. The numerical simulation results show that the triangular hierarchical honeycomb provides the best performance compared to the other two hierarchical honeycombs, and features more than twice the energy absorbed by the regular honeycomb under similar loading conditions. We also proposemore » a parametric study correlating the microstructure parameters (hierarchical length ratio r and the number of sub cells N) to the energy absorption capacity of these hierarchical honeycombs. The triangular hierarchical honeycomb with N = 2 and r = 1/8 shows the highest energy absorption capacity among all the investigated cases, and this configuration could be employed as a benchmark for the design of future safety protective systems.« less

Triangular Black Phosphorus Atomic Layers by Liquid Exfoliation.

PubMed

Seo, Soonjoo; Lee, Hyun Uk; Lee, Soon Chang; Kim, Yooseok; Kim, Hyeran; Bang, Junhyeok; Won, Jonghan; Kim, Youngjun; Park, Byoungnam; Lee, Jouhahn

2016-03-30

Few-layer black phosphorus (BP) is the most promising material among the two-dimensional materials due to its layered structure and the excellent semiconductor properties. Currently, thin BP atomic layers are obtained mostly by mechanical exfoliation of bulk BP, which limits applications in thin-film based electronics due to a scaling process. Here we report highly crystalline few-layer black phosphorus thin films produced by liquid exfoliation. We demonstrate that the liquid-exfoliated BP forms a triangular crystalline structure on SiO2/Si (001) and amorphous carbon. The highly crystalline BP layers are faceted with a preferred orientation of the (010) plane on the sharp edge, which is an energetically most favorable facet according to the density functional theory calculations. Our results can be useful in understanding the triangular BP structure for large-area applications in electronic devices using two-dimensional materials. The sensitivity and selectivity of liquid-exfoliated BP to gas vapor demonstrate great potential for practical applications as sensors.

Triangular Black Phosphorus Atomic Layers by Liquid Exfoliation

PubMed Central

Seo, Soonjoo; Lee, Hyun Uk; Lee, Soon Chang; Kim, Yooseok; Kim, Hyeran; Bang, Junhyeok; Won, Jonghan; Kim, Youngjun; Park, Byoungnam; Lee, Jouhahn

2016-01-01

Few-layer black phosphorus (BP) is the most promising material among the two-dimensional materials due to its layered structure and the excellent semiconductor properties. Currently, thin BP atomic layers are obtained mostly by mechanical exfoliation of bulk BP, which limits applications in thin-film based electronics due to a scaling process. Here we report highly crystalline few-layer black phosphorus thin films produced by liquid exfoliation. We demonstrate that the liquid-exfoliated BP forms a triangular crystalline structure on SiO2/Si (001) and amorphous carbon. The highly crystalline BP layers are faceted with a preferred orientation of the (010) plane on the sharp edge, which is an energetically most favorable facet according to the density functional theory calculations. Our results can be useful in understanding the triangular BP structure for large-area applications in electronic devices using two-dimensional materials. The sensitivity and selectivity of liquid-exfoliated BP to gas vapor demonstrate great potential for practical applications as sensors. PMID:27026070

Triangular Libration Points in the CR3BP with Radiation, Triaxiality and Potential from a Belt

NASA Astrophysics Data System (ADS)

Singh, Jagadish; Taura, Joel John

2017-07-01

In this paper the equations of motion of the circular restricted three body problem is modified to include radiation of the bigger primary, triaxiality of the smaller primary; and gravitational potential created by a belt. We have obtained that due to the perturbations, the locations of the triangular libration points and their linear stability are affected. The points move towards the bigger primary due to the resultant effect of the perturbations. Triangular libration points are stable for 0<μ<μc0<μ<μc and unstable for μc≤μ≤12μc≤μ≤12, where μcμc is the critical mass ratio affected by the perturbations. The radiation of the bigger primary and triaxiality of the smaller primary have destabilizing propensities, whereas the potential created by the belt has stabilizing propensity. This model could be applied in the study of the motion of a dust particle near radiating -triaxial binary system surrounded by a belt.

Linearized Lifting-Surface and Lifting-line Evaluations of Sidewash Behind Rolling Triangular Wings at Supersonic Speeds

NASA Technical Reports Server (NTRS)

Bobbitt, Percy J

1957-01-01

The lifting-surface sidewash behind rolling triangular wings has been derived for a range of supersonic Mach numbers for which the wing leading edges remain swept behind the mark cone emanating from the wing apex. Variations of the sidewash with longitudinal distance in the vertical plane of symmetry are presented in graphical form. An approximate expression for the sidewash has been developed by means of an approach using a horseshoe-vortex approximate-lifting-line theory. By use of this approximate expression, sidewash may be computed for wings of arbitrary plan form and span loading. A comparison of the sidewash computed by lifting-surface and lifting-line expressions for the triangular wing showed good agreement except in the vicinity of the trailing edge when the leading edge approached the sonic condition. An illustrative calculation has been made of the force induced by the wing sidewash on a vertical tail located in various longitudinal positions.

Characterization of external potential for field emission resonances and its applications on nanometer-scale measurements

NASA Astrophysics Data System (ADS)

Lu, Shin-Ming; Chan, Wen-Yuan; Su, Wei-Bin; Pai, Woei Wu; Liu, Hsiang-Lin; Chang, Chia-Seng

2018-04-01

The form of the external potential (FEP) for generating field emission resonance (FER) in a scanning tunneling microscopy (STM) junction is usually assumed to be triangular. We demonstrate that this assumption can be examined using a plot that can characterize FEP. The plot is FER energies versus the corresponding distances between the tip and sample. Through this energy–distance relationship, we discover that the FEP is nearly triangular for a blunt STM tip. However, the assumption of a triangular potential form is invalid for a sharp tip. The disparity becomes more severe as the tip is sharper. We demonstrate that the energy–distance plot can be exploited to determine the barrier width in field emission and estimate the effective sharpness of an STM tip. Because FERs were observed on Pb islands grown on the Cu(111) surface in this study, determination of the tip sharpness enabled the derivation of the subtle expansion deformation of Pb islands due to electrostatic force in the STM junction.

Adaptive neural control of MIMO nonlinear systems with a block-triangular pure-feedback control structure.

PubMed

Chen, Zhenfeng; Ge, Shuzhi Sam; Zhang, Yun; Li, Yanan

2014-11-01

This paper presents adaptive neural tracking control for a class of uncertain multiinput-multioutput (MIMO) nonlinear systems in block-triangular form. All subsystems within these MIMO nonlinear systems are of completely nonaffine pure-feedback form and allowed to have different orders. To deal with the nonaffine appearance of the control variables, the mean value theorem is employed to transform the systems into a block-triangular strict-feedback form with control coefficients being couplings among various inputs and outputs. A systematic procedure is proposed for the design of a new singularity-free adaptive neural tracking control strategy. Such a design procedure can remove the couplings among subsystems and hence avoids the possible circular control construction problem. As a consequence, all the signals in the closed-loop system are guaranteed to be semiglobally uniformly ultimately bounded. Moreover, the outputs of the systems are ensured to converge to a small neighborhood of the desired trajectories. Simulation studies verify the theoretical findings revealed in this paper.

Phase transitions and critical properties in the antiferromagnetic Ising model on a layered triangular lattice with allowance for intralayer next-nearest-neighbor interactions

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

Badiev, M. K., E-mail: m-zagir@mail.ru; Murtazaev, A. K.; Ramazanov, M. K.

2016-10-15

The phase transitions (PTs) and critical properties of the antiferromagnetic Ising model on a layered (stacked) triangular lattice have been studied by the Monte Carlo method using a replica algorithm with allowance for the next-nearest-neighbor interactions. The character of PTs is analyzed using the histogram technique and the method of Binder cumulants. It is established that the transition from the disordered to paramagnetic phase in the adopted model is a second-order PT. Static critical exponents of the heat capacity (α), susceptibility (γ), order parameter (β), and correlation radius (ν) and the Fischer exponent η are calculated using the finite-size scalingmore » theory. It is shown that (i) the antiferromagnetic Ising model on a layered triangular lattice belongs to the XY universality class of critical behavior and (ii) allowance for the intralayer interactions of next-nearest neighbors in the adopted model leads to a change in the universality class of critical behavior.« less

Strain-induced intervortex interaction and vortex lattices in tetragonal superconductors

DOE PAGES

Lin, Shi -Zeng; Kogan, Vladimir G.

2017-02-22

In superconductors with strong coupling between superconductivity and elasticity manifested in a strong dependence of transition temperature on pressure, there is an additional contribution to intervortex interactions due to the strain field generated by vortices. When vortex lines are along the c axis of a tetragonal crystal, a square vortex lattice (VL) is favored at low vortex densities, because the vortex-induced strains contribution to the intervortex interactions is long range. At intermediate magnetic fields, the triangular lattice is stabilized. Furthermore, the triangular lattice evolves to the square lattice upon increasing magnetic field, and eventually the system locks to the squaremore » structure. We argue, however, that as magnetic field approaches the upper critical field H c2 the elastic intervortex interactions disappear faster than the standard London interactions, so that VL should return to the triangular structure. Our results are compared to VLs observed in the heavy fermion superconductor CeCoIn 5.« less

Higher-n triangular dilatonic black holes

NASA Astrophysics Data System (ADS)

Zadora, Anton; Gal'tsov, Dmitri V.; Chen, Chiang-Mei

2018-04-01

Dilaton gravity with the form fields is known to possess dyon solutions with two horizons for the discrete "triangular" values of the dilaton coupling constant a =√{ n (n + 1) / 2 }. This sequence first obtained numerically and then explained analytically as consequence of the regularity of the dilaton, should have some higher-dimensional and/or group theoretical origin. Meanwhile, this origin was explained earlier only for n = 1 , 2 in which cases the solutions were known analytically. We extend this explanation to n = 3 , 5 presenting analytical triangular solutions for the theory with different dilaton couplings a , b in electric and magnetic sectors in which case the quantization condition reads ab = n (n + 1) / 2. The solutions are derived via the Toda chains for B2 and G2 Lie algebras. They are found in the closed form in general D space-time dimensions. Solutions satisfy the entropy product rules indicating on the microscopic origin of their entropy and have negative binding energy in the extremal case.

Engineering triangular carbon quantum dots with unprecedented narrow bandwidth emission for multicolored LEDs.

PubMed

Yuan, Fanglong; Yuan, Ting; Sui, Laizhi; Wang, Zhibin; Xi, Zifan; Li, Yunchao; Li, Xiaohong; Fan, Louzhen; Tan, Zhan'ao; Chen, Anmin; Jin, Mingxing; Yang, Shihe

2018-06-08

Carbon quantum dots (CQDs) have emerged as promising materials for optoelectronic applications on account of carbon's intrinsic merits of high stability, low cost, and environment-friendliness. However, the CQDs usually give broad emission with full width at half maximum exceeding 80 nm, which fundamentally limit their display applications. Here we demonstrate multicolored narrow bandwidth emission (full width at half maximum of 30 nm) from triangular CQDs with a quantum yield up to 54-72%. Detailed structural and optical characterizations together with theoretical calculations reveal that the molecular purity and crystalline perfection of the triangular CQDs are key to the high color-purity. Moreover, multicolored light-emitting diodes based on these CQDs display good stability, high color-purity, and high-performance with maximum luminance of 1882-4762 cd m -2 and current efficiency of 1.22-5.11 cd A -1 . This work will set the stage for developing next-generation high-performance CQDs-based light-emitting diodes.

Striped, honeycomb, and twisted moiré patterns in surface adsorption systems with highly degenerate commensurate ground states

NASA Astrophysics Data System (ADS)

Elder, K. R.; Achim, C. V.; Granato, E.; Ying, S. C.; Ala-Nissila, T.

2017-11-01

Atomistically thin adsorbate layers on surfaces with a lattice mismatch display complex spatial patterns and ordering due to strain-driven self-organization. In this work, a general formalism to model such ultrathin adsorption layers that properly takes into account the competition between strain and adhesion energy of the layers is presented. The model is based on the amplitude expansion of the two-dimensional phase field crystal (PFC) model, which retains atomistic length scales but allows relaxation of the layers at diffusive time scales. The specific systems considered here include cases where both the film and the adsorption potential can have either honeycomb (H) or triangular (T) symmetry. These systems include the so-called (1 ×1 ) , (√{3 }×√{3 }) R 30∘ , (2 ×2 ) , (√{7 }×√{7 }) R 19 .1∘ , and other higher order states that can contain a multitude of degenerate commensurate ground states. The relevant phase diagrams for many combinations of the H and T systems are mapped out as a function of adhesion strength and misfit strain. The coarsening patterns in some of these systems is also examined. The predictions are in good agreement with existing experimental data for selected strained ultrathin adsorption layers.

Blast Injuries: From Improvised Explosive Device Blasts to the Boston Marathon Bombing.

PubMed

Singh, Ajay K; Ditkofsky, Noah G; York, John D; Abujudeh, Hani H; Avery, Laura A; Brunner, John F; Sodickson, Aaron D; Lev, Michael H

2016-01-01

Although most trauma centers have experience with the imaging and management of gunshot wounds, in most regions blast wounds such as the ones encountered in terrorist attacks with the use of improvised explosive devices (IEDs) are infrequently encountered outside the battlefield. As global terrorism becomes a greater concern, it is important that radiologists, particularly those working in urban trauma centers, be aware of the mechanisms of injury and the spectrum of primary, secondary, tertiary, and quaternary blast injury patterns. Primary blast injuries are caused by barotrauma from the initial increased pressure of the explosive detonation and the rarefaction of the atmosphere immediately afterward. Secondary blast injuries are caused by debris carried by the blast wind and most often result in penetrating trauma from small shrapnel. Tertiary blast injuries are caused by the physical displacement of the victim and the wide variety of blunt or penetrating trauma sustained as a result of the patient impacting immovable objects such as surrounding cars, walls, or fences. Quaternary blast injuries include all other injuries, such as burns, crush injuries, and inhalational injuries. Radiography is considered the initial imaging modality for assessment of shrapnel and fractures. Computed tomography is the optimal test to assess penetrating chest, abdominal, and head trauma. The mechanism of blast injuries and the imaging experience of the victims of the Boston Marathon bombing are detailed, as well as musculoskeletal, neurologic, gastrointestinal, and pulmonary injury patterns from blast injuries. ©RSNA, 2016.

SU-E-J-155: Utilizing Varian TrueBeam Developer Mode for the Quantification of Mechanical Limits and the Simulation of 4D Respiratory Motion

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

Moseley, D; Dave, M

Purpose: Use Varian TrueBeam Developer mode to quantify the mechanical limits of the couch and to simulate 4D respiratory motion. Methods: An in-house MATLAB based GUI was created to make the BEAM XML files. The couch was moved in a triangular wave in the S/I direction with varying amplitudes (1mm, 5mm, 10mm, and 50mm) and periods (3s, 6s, and 9s). The periods were determined by specifying the speed. The theoretical positions were compared to the values recorded by the machine at 50 Hz. HD videos were taken for certain tests as external validation. 4D Respiratory motion was simulated by anmore » A/P MV beam being delivered while the couch moved in an elliptical manner. The ellipse had a major axis of 2 cm (S/I) and a minor axis of 1 cm (A/P). Results: The path planned by the TrueBeam deviated from the theoretical triangular form as the speed increased. Deviations were noticed starting at a speed of 3.33 cm/s (50mm amplitude, 6s period). The greatest deviation occurred in the 50mm- 3s sequence with a correlation value of −0.13 and a 27% time increase; the plan essentially became out of phase. Excluding these two, the plans had correlation values of 0.99. The elliptical sequence effectively simulated a respiratory pattern with a period of 6s. The period could be controlled by changing the speeds or the dose rate. Conclusion: The work first shows the quantification of the mechanical limits of the couch and the speeds at which the proposed plans begin to deviate. These limits must be kept in mind when programming other couch sequences. The methodology can be used to quantify the limits of other axes. Furthermore, the work shows the possibility of creating 4D respiratory simulations without using specialized phantoms or motion-platforms. This can be further developed to program patient-specific breathing patterns.« less

Correlation between the graft-host junction of penetrating keratoplasty by anterior segment-optical coherence tomography and the magnitude of postoperative astigmatism.

PubMed

Nassar, Ghada Azab; Arfeen, Shaimaa Abd El Salam

2017-07-01

This study aimed to evaluate the alignment pattern of the graft-host junction after penetrating keratoplasty (PK) by anterior segment-optical coherence tomography (AS-OCT) and to correlate this pattern with the magnitude of postoperative astigmatism. This retrospective observational study was carried out on forty patients who underwent PK from February 2013 to August 2014. AS-OCT was performed, and the graft-host junctions were classified into well-apposed junction, malapposed junction, and equally apposed junction. Mal-apposition is subdivided into gap and protrusion. The correlations between clinical characteristics, wound profiles from the AS-OCT, and the magnitude of postoperative astigmatism by Sirius camera (Costruzione Strumenti Oftalmici [CSO], Florence, Italy (CSO, Sirius), were analyzed. Graft-host junctions from forty patients were analyzed; 18 eyes had well-apposed junctions, ten eyes had malapposed junctions, and 12 had equally apposed junctions. The mean cylinder was -9.44 ± -4.00D in well-apposed group, -13.40 ± -5.01D in malapposed group, and -4.67 ± -0.94D in equally apposed group. Alignment pattern of the graft-host junction correlated significantly with the magnitude of astigmatism (P = 0.034). Preoperative corneal diseases did not have an effect on the magnitude of astigmatism (P = 0.123). The alignment pattern of the graft-host junction by AS-OCT can explain the postoperative astigmatism after PK where it correlates significantly with the magnitude of astigmatism.

Nitrification in the Upper Mississippi River: Patterns, controls, and contribution to the NO3- budget

USGS Publications Warehouse

Strauss, E.A.; Richardson, W.B.; Bartsch, L.A.; Cavanaugh, J.C.; Bruesewitz, D.A.; Imker, H.; Heinz, J.A.; Soballe, D.M.

2004-01-01

We measured nitrification rates in sediment samples collected from a variety of aquatic habitats in Navigation Pool 8 of the Upper Mississippi River (UMR) 7 times between May 2000 and October 2001. We also conducted nutrient-enrichment experiments and analyzed vertical profiles of sediment to determine factors regulating nitrification. Nitrification rates were relatively high compared to other ecosystems (ranging from 0-8.25 ??g N cm-2 h-1) and exhibited significant temporal and spatial patterns. Nitrification rates were greatest during the summer and spring compared to autumn and winter (ANOVA, p < 0.05) and were greater in contiguous backwater and impounded habitats compared to main and side-channel habitats (p < 0.05). Regression analysis indicated that nitrification rates were weakly (r 2 = 0.18, p < 0.0001) related to temperature and exchangeable NH4+ of the sediment. However, nutrient-enrichment experiments showed that NH4+ availability did not limit nitrification in 3 sediment types with variable organic matter. Vertical profiles of sediment cores demonstrated that oxygen concentration and nitrification had similar patterns suggesting that nitrification may be limited by oxygen penetration into sediments. We conclude that temperature and sediment NH4+ can be useful for predicting broad-scale temporal and spatial nitrification patterns, respectively, but oxygen penetration into the sediments likely regulates nitrification rates in much of the UMR. Overall, we estimated that nitrification produces 6982 mt N/y of NO3- or 7% of the total annual NO3- budget.

Application of cylindrical, triangular and hemispherical dimples in the film cooling technology

NASA Astrophysics Data System (ADS)

Khalatov, A. A.; Panchenko, N. A.; Severin, S. D.

2017-11-01

The results of film cooling numerical simulation over a flat plate with coolant supply through a single span-wise array of inclined (α = 30°) holes arranged inside cylindrical, triangular, and hemispherical dimples are represented in the paper. Such configurations are of a great practical interest for application in advanced blade cooling systems of high-performance gas turbines. The schemes with coolant supply into triangular and hemispherical dimples were first proposed and patented by the IET of the NAS of Ukraine. For numerical simulation the ANSYS CFX 14 commercial code was used. Numerical simulation were carried out in a wide range of the blowing ratio parameter varied from 0.5 to 2.0. For low blowing ratio parameter (m = 0.5) the laterally averaged film cooling efficiency is actually the same for all investigated schemes over the main film cooling area. In this area, the most simple in terms of the film cooling production technology configuration can be used. At the medium and high blowing ratios (m = 1.0 or higher) all investigated film cooling schemes allow to increase the laterally averaged film cooling efficiency in comparison with the traditional cooling scheme with single row of incline holes. In this case the configuration with coolant supply into triangular dimples of the «crater» type demonstrates the best film cooling efficiency due to significant reduction in the intensity and scale of the “kidney” vortex beyond configuration, as well as due to decrease in the coolant blowing non-uniformity factor.

Efficient computer algebra algorithms for polynomial matrices in control design

NASA Technical Reports Server (NTRS)

Baras, J. S.; Macenany, D. C.; Munach, R.

1989-01-01

The theory of polynomial matrices plays a key role in the design and analysis of multi-input multi-output control and communications systems using frequency domain methods. Examples include coprime factorizations of transfer functions, cannonical realizations from matrix fraction descriptions, and the transfer function design of feedback compensators. Typically, such problems abstract in a natural way to the need to solve systems of Diophantine equations or systems of linear equations over polynomials. These and other problems involving polynomial matrices can in turn be reduced to polynomial matrix triangularization procedures, a result which is not surprising given the importance of matrix triangularization techniques in numerical linear algebra. Matrices with entries from a field and Gaussian elimination play a fundamental role in understanding the triangularization process. In the case of polynomial matrices, matrices with entries from a ring for which Gaussian elimination is not defined and triangularization is accomplished by what is quite properly called Euclidean elimination. Unfortunately, the numerical stability and sensitivity issues which accompany floating point approaches to Euclidean elimination are not very well understood. New algorithms are presented which circumvent entirely such numerical issues through the use of exact, symbolic methods in computer algebra. The use of such error-free algorithms guarantees that the results are accurate to within the precision of the model data--the best that can be hoped for. Care must be taken in the design of such algorithms due to the phenomenon of intermediate expressions swell.

Fabrication of a Highly Sensitive Single Aligned TiO2 and Gold Nanoparticle Embedded TiO2 Nano-Fiber Gas Sensor.

PubMed

Nikfarjam, Alireza; Hosseini, Seyedsina; Salehifar, Nahideh

2017-05-10

In this research, a single-aligned nanofiber of pure TiO 2 and gold nanoparticle (GNP)-TiO 2 were fabricated using a novel electro-spinning procedure equipped with secondary electrostatic fields on highly sharp triangular and rectangular electrodes provided for gas sensing applications. The sol used for spinning nanofiber consisted of titanium tetraisopropoxide (C 12 H 28 O 4 Ti), acetic acid (CH 3 COOH), ethanol (C 2 H 5 OH), polyvinylpyrrolidone (PVP), and gold nanoparticle solution. FE-SEM, TEM, and XRD were used to characterize the single nanofiber. In triangular electrodes, the electrostatic voltage for aligning single nanofiber between electrodes depends on the angle tip of the electrode, which was around 1.4-2.1, 2-2.9, and 3.2-4.1 kV for 30°, 45°, and 60°, respectively. However, by changing the shape of the electrodes to rectangular samples and by increasing distance between electrodes from 100 to 200 μm, electro-spinning applied voltage decreased. Response of pure TiO 2 single nanofiber sensor was measured for 30-200 ppb carbon monoxide gas. The triangular sample revealed better response and lower threshold than the rectangular sample. Adding appropriate amounts of GNP decreased the operating temperature and increased the responses. CO concentration threshold for the pure TiO 2 and GNP-TiO 2 triangular samples was about 5 ppb and 700 ppt, respectively.

Penetrating and blunt trauma to the neck: clinical presentation, assessment and emergency management.

PubMed

Perdonck, P; de Schoutheets, J C; Monsieurs, K G; Van Laer, C; Vander Poorten, V; Vanderveken, O

Penetrating and blunt trauma to the neck: clinical presentation, assessment ana emergency management. In Belgium, and even in Western Europe, penetrating and blunt injury to the neck is relatively uncommon in both the civilian and military populations. Pre-hospital and emergency assessment and management will therefore always prove challenging, as individual exposure to this specific type of injury remains low. Historically, the neck has been divided into three anatomical zones with specific landmarks to guide the diagnostic and therapeutic approach to penetrating neck injuries. Most penetrating injuries need to be explored surgically, although with the advent of multi-detector computed tomographic angiography (MDCTA), which yields high diagnostic sensitivity, this inflexible approach has recently changed to a more targeted management, based on clinical, radiographic and, if deemed necessary, endoscopic findings. However, some authors have addressed their concern about this novel, 'no-zone' approach, since the risk of missing less apparent aerodigestive tract injuries may increase. It is recommended, therefore, that all patients with penetrating neck injuries be closely observed, irrespective of the initial findings. The incidence of blunt neck injury is much lower, and this makes risk assessment and management even more difficult in comparison with penetrating injuries. Again, MDCTA is most often the first diagnostic tool if a blunt neck injury is suspected, due to its good sensitivity for blunt cerebrovascular injuries (BCVI) as well as for aerodigestive tract injuries. Specific patterns of injury and unexpected neurological and neuro-radiological findings in trauma patients should always warrant further investigation. Despite ongoing debate, systemic anticoagulation is recommended for most BCVI, sometimes combined with endovascular treatment. Aerodigestive tract injuries may present dramatically, but are often more subtle, making the diagnosis more difficult than other types of neck injuries. Treatment may be conservative if damage is minimal, but surgery is warranted in all other cases.

Automatic two- and three-dimensional mesh generation based on fuzzy knowledge processing

NASA Astrophysics Data System (ADS)

Yagawa, G.; Yoshimura, S.; Soneda, N.; Nakao, K.

1992-09-01

This paper describes the development of a novel automatic FEM mesh generation algorithm based on the fuzzy knowledge processing technique. A number of local nodal patterns are stored in a nodal pattern database of the mesh generation system. These nodal patterns are determined a priori based on certain theories or past experience of experts of FEM analyses. For example, such human experts can determine certain nodal patterns suitable for stress concentration analyses of cracks, corners, holes and so on. Each nodal pattern possesses a membership function and a procedure of node placement according to this function. In the cases of the nodal patterns for stress concentration regions, the membership function which is utilized in the fuzzy knowledge processing has two meanings, i.e. the “closeness” of nodal location to each stress concentration field as well as “nodal density”. This is attributed to the fact that a denser nodal pattern is required near a stress concentration field. What a user has to do in a practical mesh generation process are to choose several local nodal patterns properly and to designate the maximum nodal density of each pattern. After those simple operations by the user, the system places the chosen nodal patterns automatically in an analysis domain and on its boundary, and connects them smoothly by the fuzzy knowledge processing technique. Then triangular or tetrahedral elements are generated by means of the advancing front method. The key issue of the present algorithm is an easy control of complex two- or three-dimensional nodal density distribution by means of the fuzzy knowledge processing technique. To demonstrate fundamental performances of the present algorithm, a prototype system was constructed with one of object-oriented languages, Smalltalk-80 on a 32-bit microcomputer, Macintosh II. The mesh generation of several two- and three-dimensional domains with cracks, holes and junctions was presented as examples.

Not all intestinal traumatic injuries are the same: a comparison of surgically treated blunt vs. penetrating injuries.

PubMed

Adam, Nadir; Sorensen, Victor; Skinner, Ruby

2015-01-01

Traumatic intestinal injuries are less common with blunt compared to penetrating mechanisms of trauma and blunt injuries are often associated with diagnostic delays. The purpose of this study is to evaluate differences in the characteristics and outcomes between blunt and penetrating intestinal injuries to facilitate insight into optimal recognition and management. A retrospective analysis of trauma admissions from January 2009 to June 2011 was performed. Patient demographics, ISS, early shock, injury type, timing to OR, blood loss and transfusions, surgical management, infections, EC fistulas, enteric leaks, LOS and mortality were compared. Demographics - There was 3866 blunt admissions and 966 penetrating admissions to our level II trauma centre (Total n=4832) during this interval. The final study group comprised n=131 patients treated for intestinal injuries. Blunt n=54 (BI) vs. penetrating (PI) n=77. Age was similar between the groups: (BI 34 SD 12 vs. PI 30 SD 12). Comorbid conditions were similar as were ED hypotension and blood transfusions. Blunt mechanisms had higher ISS; BI (20 SD 14) vs. PI (16 SD 12), p=0.08 and organ specific injury scales were higher in blunt injuries. Operative Management - Time to operation was higher in BI: (500 SD 676min vs. PI 110 SD 153min, p=0.01). The use of an open abdomen technique was higher for BI: n=19 (35%) vs. PI: n=5 (6%), p=<0.001, as well as delayed intestinal repair in damage control cases. Outcomes - Anastomotic leaks were more prevalent in BI: n=4 (7%) vs. PI: n=2 (3%), p=0.38. Enteric fistulas were: (BI n=8 (15%), vs. PI n=2 (3%), p=0.02). Surgical site infections and other nosocomial infections were: (BI n=11 (20%) vs. PI n=4 (5%), p=0.02), (BI n=11 (20%) vs. PI n=2 (3%), p=0.002), respectively. Hospital and ICU LOS was: (BI=20 SD 14 vs. PI=11 SD 11, p=0.001), (BI=10 SD 10 vs. PI=5 SD 5, p=0.01) respectively. These differences were reflected in higher hospital charges in BI. Blunt and penetrating intestinal injury patterns have high injury severity. Significant operative delays occurred in the blunt injury group as well as, anastomotic failures, enteric fistulas, nosocomial infections, and higher cost. These features underscore the complexity of blunt injury patterns and warrant vigilant injury recognition to improve outcomes. Copyright © 2014 Elsevier Ltd. All rights reserved.

Flow visualization studies of transverse fuel injection patterns in a nonreacting Mach 2 combustor

NASA Technical Reports Server (NTRS)

Mcdaniel, J. C.

1987-01-01

Planar visualization images are recorded of transverse jet mixing in a supersonic combustor flowfield, without chemical reaction, using laser-induced fluorescence from iodine molecules. Digital image processing and three-dimensional display enable complete representations of fuel penetration boundary and shock surfaces corresponding to several injection geometries and pressures.

Latent classes of sexual behaviors: Prevalence, predictors, and consequences

PubMed Central

Wesche, Rose; Lefkowitz, Eva S.; Vasilenko, Sara A.

2016-01-01

Scholars of adolescent and emerging adult sexuality have recently begun to study how diverse patterns of sexual behaviors contribute to development and well-being. A person-oriented approach to studying sexual behaviors provides a nuanced understanding of sexual repertoires. The goals of this paper were to document patterns of sexual behaviors ranging from kissing to penetrative sex, and to examine how latent classes of behaviors, gender, and partner type (romantic vs. nonromantic) predict intra- and interpersonal consequences of sexual behaviors. Latent class analysis of a stratified random sample of U.S. college students revealed four classes of sexual behaviors: Kissing Only, Kissing and Touching, All Behaviors, and Oral and Penetrative Only. Compared to individuals in the All Behaviors class, individuals in the Kissing Only class were less likely to experience a positive or a negative intrapersonal consequence of sexual behaviors. Men were less likely to report a negative intrapersonal consequence than women were. Partner type predicted negative interpersonal consequences for the All Behaviors class. Implications are discussed in terms of normative sexual development, prevention, and sexual and relationship education. PMID:28163800

Arthroscopic Management of Triangular Fibrocartilage Complex Foveal Injury.

PubMed

Fujio, Keiji

2017-11-01

The deep component of triangular fibrocartilage complex (TFCC) inserts onto the fovea of the ulnar head. This component is critical to provide distal radioulnar joint stability. The surgical techniques and results of transosseous inside-out TFCC foveal repair are discussed. The rewarding results encouraged the repair of TFCC to the fovea arthroscopically. Although the results are good, the factors of age (traumatic or degenerative) and quality of stump and TFCC proper, which relate to the results should be considered in the future. Copyright © 2017 Elsevier Inc. All rights reserved.

DNA unzipping with asymmetric periodic forces: Robustness of the scaling behavior of hysteresis loop

NASA Astrophysics Data System (ADS)

Pal, Tanmoy; Kumar, Sanjay

2018-01-01

We study the effect of periodic unzipping forces (symmetric and asymmetric) on the steady-state hysteresis loop area of force-extension curves of DNA. For the triangular force, we get back the previously reported scaling exponents but for the ratchet force, we find that the scaling exponents deviate from the reported ones. We also study the temperature dependence of the scaling exponents for the triangular force. At the low-frequency regime, the choice of the scaling form determines whether the scaling exponents depend on the temperature or not.

Superconductivity in the Penson-Kolb Model on a Triangular Lattice

NASA Astrophysics Data System (ADS)

Ptok, A.; Mierzejewski, M.

2008-07-01

We investigate properties of the two-dimensional Penson-Kolb model with repulsive pair hopping interaction. In the case of a bipartite square lattice this interaction may lead to the η-type pairing, when the phase of superconducting order parameter changes from one lattice site to the neighboring one. We show that this interaction may be responsible for the onset of superconductivity also for a triangular lattice. We discuss the spatial dependence of the superconducting order parameter and demonstrate that the total momentum of the paired electrons is determined by the lattice geometry.

Frustration and correlations in stacked triangular-lattice Ising antiferromagnets

NASA Astrophysics Data System (ADS)

Burnell, F. J.; Chalker, J. T.

2015-12-01

We study multilayer triangular-lattice Ising antiferromagnets with interlayer interactions that are weak and frustrated in an abc stacking. By analyzing a coupled height model description of these systems, we show that they exhibit a classical spin liquid regime at low temperature, in which both intralayer and interlayer correlations are strong but there is no long-range order. Diffuse scattering in this regime is concentrated on a helix in reciprocal space, as observed for charge ordering in the materials LuFe2O4 and YbFe2O4 .

Explicit formulation of an anisotropic Allman/DKT 3-node thin triangular flat shell elements

NASA Astrophysics Data System (ADS)

Ertas, A.; Krafcik, J. T.; Ekwaro-Osire, S.

A simple, explicit formulation of the stiffness matrix for an anisotropic, 3-node, thin triangular, flat shell element in global coordinates is presented. An Allman triangle is used for membrane stiffness. The membrane stiffness matrix is explicitly derived by applying an Allman transformation to a Felippa 6-node linear strain triangle (LST). Bending stiffness is incorporated by the use of a discrete Kirchhoff triangle (DKT) bending triangle. Stiffness terms resulting from anisotropic membrane-bending coupling are included by integrating, in area coordinates, membrane and bending strain-displacement matrices.

Heteroclinic, Homoclinic Connections Between the Sun-Earth Triangular Points and Quasi-Satellite Orbits for Solar Observations

NASA Technical Reports Server (NTRS)

Llanos, Pedro J.; Hintz, Gerald R.; Lo, Martin W.; Miller, James K.

2013-01-01

Investigation of new orbit geometries exhibits a very attractive behavior for a spacecraft to monitor space weather coming from the Sun. Several orbit transfer mechanisms are analyzed as potential alternatives to monitor solar activity such as a sub-solar orbit or quasi-satellite orbit and short and long heteroclinic and homoclinic connections between the triangular points L(sub 4) and L(sub 5) and the collinear point L(sub 3) of the Circular Restricted Three-Body Problem (CRTBP) in the Sun-Earth system.

A Well-Balanced Central-Upwind Scheme for the 2D Shallow Water Equations on Triangular Meshes

NASA Technical Reports Server (NTRS)

Bryson, Steve; Levy, Doron

2004-01-01

We are interested in approximating solutions of the two-dimensional shallow water equations with a bottom topography on triangular meshes. We show that there is a certain flexibility in choosing the numerical fluxes in the design of semi-discrete Godunov-type central schemes. We take advantage of this fact to generate a new second-order, central-upwind method for the two-dimensional shallow water equations that is well-balanced. We demonstrate the accuracy of our method as well as its balance properties in a variety of examples.

New method for propagating the square root covariance matrix in triangular form. [using Kalman-Bucy filter

NASA Technical Reports Server (NTRS)

Choe, C. Y.; Tapley, B. D.

1975-01-01

A method proposed by Potter of applying the Kalman-Bucy filter to the problem of estimating the state of a dynamic system is described, in which the square root of the state error covariance matrix is used to process the observations. A new technique which propagates the covariance square root matrix in lower triangular form is given for the discrete observation case. The technique is faster than previously proposed algorithms and is well-adapted for use with the Carlson square root measurement algorithm.

Electronic structure and optical properties of triangular GaAs/AlGaAs quantum dots: Exciton and impurity states

NASA Astrophysics Data System (ADS)

Tiutiunnyk, A.; Akimov, V.; Tulupenko, V.; Mora-Ramos, M. E.; Kasapoglu, E.; Ungan, F.; Sökmen, I.; Morales, A. L.; Duque, C. A.

2016-03-01

Electronic structure and optical properties in equilateral triangular GaAs/Al0.3Ga0.7As quantum dots are studied extensively. The effects of donor and acceptor impurity atoms positioned in the orthocenter of the triangle, as well as of the external DC electric field are taken into account. Binding energies of the impurity, exciton energies, interband photoluminescence peak positions as well as linear and non-linear optical properties in THz range caused by transitions between excitonic states are calculated and discussed.

Study of electron-related intersubband optical properties in three coupled quantum wells wires with triangular transversal section

NASA Astrophysics Data System (ADS)

Tiutiunnyk, A.; Tulupenko, V.; Akimov, V.; Demediuk, R.; Morales, A. L.; Mora-Ramos, M. E.; Radu, A.; Duque, C. A.

2015-11-01

This work concerns theoretical study of confined electrons in a low-dimensional structure consisting of three coupled triangular GaAs/AlxGa1-xAs quantum wires. Calculations have been made in the effective mass and parabolic band approximations. In the calculations a diagonalization method to find the eigenfunctions and eigenvalues of the Hamiltonian was used. A comparative analysis of linear and nonlinear optical absorption coefficients and the relative change in the refractive index was made, which is tied to the intersubband electron transitions.

Thermodynamics of the adsorption of flexible polymers on nanowires

DOE PAGES

Vogel, Thomas; Gross, Jonathan; Bachmann, Michael

2015-03-09

Generalized-ensemble simulations enable the study of complex adsorption scenarios of a coarse-grained model polymer near an attractive nanostring, representing an ultrathin nanowire. We perform canonical and microcanonical statistical analyses to investigate structural transitions of the polymer and discuss their dependence on the temperature and on model parameters such as effective wire thickness and attraction strength. The result is a complete hyperphase diagram of the polymer phases, whose locations and stability are influenced by the effective material properties of the nanowire and the strength of the thermal fluctuations. Major structural polymer phases in the adsorbed state include compact droplets attached tomore » or wrapping around the wire, and tubelike conformations with triangular pattern that resemble ideal boron nanotubes. In conclusion, the classification of the transitions is performed by microcanonical inflection-point analysis.« less

Observation of Two-Dimensional Localized Jones-Roberts Solitons in Bose-Einstein Condensates

NASA Astrophysics Data System (ADS)

Meyer, Nadine; Proud, Harry; Perea-Ortiz, Marisa; O'Neale, Charlotte; Baumert, Mathis; Holynski, Michael; Kronjäger, Jochen; Barontini, Giovanni; Bongs, Kai

2017-10-01

Jones-Roberts solitons are the only known class of stable dark solitonic solutions of the nonlinear Schrödinger equation in two and three dimensions. They feature a distinctive elongated elliptical shape that allows them to travel without change of form. By imprinting a triangular phase pattern, we experimentally generate two-dimensional Jones-Roberts solitons in a three-dimensional atomic Bose-Einstein condensate. We monitor their dynamics, observing that this kind of soliton is indeed not affected by dynamic (snaking) or thermodynamic instabilities, that instead make other classes of dark solitons unstable in dimensions higher than one. Our results confirm the prediction that Jones-Roberts solitons are stable solutions of the nonlinear Schrödinger equation and promote them for applications beyond matter wave physics, like energy and information transport in noisy and inhomogeneous environments.

Rogue waves for a discrete (2+1)-dimensional Ablowitz-Ladik equation in the nonlinear optics and Bose-Einstein condensation

NASA Astrophysics Data System (ADS)

Wu, Xiao-Yu; Tian, Bo; Chai, Han-Peng; Du, Zhong

2018-03-01

Under investigation in this paper is a discrete (2+1)-dimensional Ablowitz-Ladik equation, which is used to model the nonlinear waves in the nonlinear optics and Bose-Einstein condensation. Employing the Kadomtsev-Petviashvili hierarchy reduction, we obtain the rogue wave solutions in terms of the Gramian. We graphically study the first-, second- and third-order rogue waves with the influence of the focusing coefficient and coupling strength. When the value of the focusing coefficient increases, both the peak of the rogue wave and background decrease. When the value of the coupling strength increases, the rogue wave raises and decays in a shorter time. High-order rogue waves are exhibited as one single highest peak and some lower humps, and such lower humps are shown as the triangular and circular patterns.

Continuous Attractor Network Model for Conjunctive Position-by-Velocity Tuning of Grid Cells

PubMed Central

Si, Bailu; Romani, Sandro; Tsodyks, Misha

2014-01-01

The spatial responses of many of the cells recorded in layer II of rodent medial entorhinal cortex (MEC) show a triangular grid pattern, which appears to provide an accurate population code for animal spatial position. In layer III, V and VI of the rat MEC, grid cells are also selective to head-direction and are modulated by the speed of the animal. Several putative mechanisms of grid-like maps were proposed, including attractor network dynamics, interactions with theta oscillations or single-unit mechanisms such as firing rate adaptation. In this paper, we present a new attractor network model that accounts for the conjunctive position-by-velocity selectivity of grid cells. Our network model is able to perform robust path integration even when the recurrent connections are subject to random perturbations. PMID:24743341

Stepwise Synthesis of Giant Unilamellar Vesicles on a Microfluidic Assembly Line

PubMed Central

2011-01-01

Among the molecular milieu of the cell, the membrane bilayer stands out as a complex and elusive synthetic target. We report a microfluidic assembly line that produces uniform cellular compartments from droplet, lipid, and oil/water interface starting materials. Droplets form in a lipid-containing oil flow and travel to a junction where the confluence of oil and extracellular aqueous media establishes a flow-patterned interface that is both stable and reproducible. A triangular post mediates phase transfer bilayer assembly by deflecting droplets from oil, through the interface, and into the extracellular aqueous phase to yield a continuous stream of unilamellar phospholipid vesicles with uniform and tunable size. The size of the droplet precursor dictates vesicle size, encapsulation of small-molecule cargo is highly efficient, and the single bilayer promotes functional insertion of a bacterial transmembrane pore. PMID:21309555

A Bayesian approach for calibrating probability judgments

NASA Astrophysics Data System (ADS)

Firmino, Paulo Renato A.; Santana, Nielson A.

2012-10-01

Eliciting experts' opinions has been one of the main alternatives for addressing paucity of data. In the vanguard of this area is the development of calibration models (CMs). CMs are models dedicated to overcome miscalibration, i.e. judgment biases reflecting deficient strategies of reasoning adopted by the expert when inferring about an unknown. One of the main challenges of CMs is to determine how and when to intervene against miscalibration, in order to enhance the tradeoff between costs (time spent with calibration processes) and accuracy of the resulting models. The current paper dedicates special attention to this issue by presenting a dynamic Bayesian framework for monitoring, diagnosing, and handling miscalibration patterns. The framework is based on Beta-, Uniform, or Triangular-Bernoulli models and classes of judgmental calibration theories. Issues regarding the usefulness of the proposed framework are discussed and illustrated via simulation studies.

Closure of the Radial Forearm Free Flap Donor Site Using the Combined Local Triangular Full-Thickness Skin Graft.

PubMed

Moreno-Sánchez, Manuel; González-García, Raúl; Ruiz-Laza, Luis; Manzano Solo de Zaldívar, Damián; Moreno-García, Carlos; Monje, Florencio

2016-01-01

Traditional donor-site closure has been associated with serious esthetic and functional morbidity. The purpose of this study was to assess morbidity in esthetics and function and measure the postoperative complications of the radial forearm free flap (RFFF) donor site after using combined local triangular full-thickness skin grafting. This prospective study of patients who underwent reconstruction of head and neck defects using an RFFF was conducted from July 2008 through December 2014. The donor site was repaired with a combined local triangular full-thickness skin graft. Quality of the scar, color match, tendon exposure, presence of necrosis, dehiscence of the suture, and presence of dysesthesia were recorded and analyzed using SPSS 21.0 software. One hundred consecutive patients (71 male and 29 female) underwent RFFF harvesting. RFFF donor-site defects ranged from 15 to 70 cm2; partial skin graft loss occurred in 7% of patients. Five patients (5%) had small dehiscences of the forearm skin graft, and 2 cases (2%) presented tendon exposure. In all cases, these sites healed secondarily by conservative management, with no final impairment of function. Esthetic results were considered excellent in 87%, good in 11%, and suboptimal in 2% of the cases. The combined local triangular full-thickness skin graft is a reliable method for closing RFFF donor-site defects because it obviates a second surgical site, it provides excellent color match and pliability, and it can be used for covering large defects of the donor site. Copyright © 2016 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Improved-resolution real-time skin-dose mapping for interventional fluoroscopic procedures

NASA Astrophysics Data System (ADS)

Rana, Vijay K.; Rudin, Stephen; Bednarek, Daniel R.

2014-03-01

We have developed a dose-tracking system (DTS) that provides a real-time display of the skin-dose distribution on a 3D patient graphic during fluoroscopic procedures. Radiation dose to individual points on the skin is calculated using exposure and geometry parameters from the digital bus on a Toshiba C-arm unit. To accurately define the distribution of dose, it is necessary to use a high-resolution patient graphic consisting of a large number of elements. In the original DTS version, the patient graphics were obtained from a library of population body scans which consisted of larger-sized triangular elements resulting in poor congruence between the graphic points and the x-ray beam boundary. To improve the resolution without impacting real-time performance, the number of calculations must be reduced and so we created software-designed human models and modified the DTS to read the graphic as a list of vertices of the triangular elements such that common vertices of adjacent triangles are listed once. Dose is calculated for each vertex point once instead of the number of times that a given vertex appears in multiple triangles. By reformatting the graphic file, we were able to subdivide the triangular elements by a factor of 64 times with an increase in the file size of only 1.3 times. This allows a much greater number of smaller triangular elements and improves resolution of the patient graphic without compromising the real-time performance of the DTS and also gives a smoother graphic display for better visualization of the dose distribution.