Characterization of a bent Laue double-crystal beam-expanding monochromator

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

Martinson, Mercedes; Samadi, Nazanin; Shi, Xianbo

A bent Laue double-crystal monochromator system has been designed for vertically expanding the X-ray beam at the Canadian Light Source's BioMedical Imaging and Therapy beamlines. Expansion by a factor of 12 has been achieved without deteriorating the transverse coherence of the beam, allowing phase-based imaging techniques to be performed with high flux and a large field of view. However, preliminary studies revealed a lack of uniformity in the beam, presumed to be caused by imperfect bending of the silicon crystal wafers used in the system. Results from finite-element analysis of the system predicted that the second crystal would be mostmore » severely affected and has been shown experimentally. It has been determined that the majority of the distortion occurs in the second crystal and is likely caused by an imperfection in the surface of the bending frame. Here, measurements were then taken to characterize the bending of the crystal using both mechanical and diffraction techniques. In particular, two techniques commonly used to map dislocations in crystal structures have been adapted to map local curvature of the bent crystals. One of these, a variation of Berg–Berrett topography, has been used to quantify the diffraction effects caused by the distortion of the crystal wafer. This technique produces a global mapping of the deviation of the diffraction angle relative to a perfect cylinder. Finally, this information is critical for improving bending and measuring tolerances of imperfections by correlating this mapping to areas of missing intensity in the beam.« less

Estimation of strength in different extra Watson-Crick hydrogen bonds in DNA double helices through quantum chemical studies.

PubMed

Bandyopadhyay, D; Bhattacharyya, D

2006-10-15

It was shown earlier, from database analysis, model building studies, and molecular dynamics simulations that formation of cross-strand bifurcated or Extra Watson-Crick hydrogen (EWC) bonds between successive base pairs may lead to extra rigidity to DNA double helices of certain sequences. The strengths of these hydrogen bonds are debatable, however, as they do not have standard linear geometry criterion. We have therefore carried out detailed ab initio quantum chemical studies using RHF/6-31G(2d,2p) and B3LYP/6-31G(2p,2d) basis sets to determine strengths of several bent hydrogen bonds with different donor and acceptors. Interaction energy calculations, corrected for the basis set superposition errors, suggest that N-H...O type bent EWC hydrogen bonds are possible along same strands or across the strands between successive base pairs, leading to significant stability (ca. 4-9 kcal/mol). The N-H...N and C-H...O type interactions, however, are not so stabilizing. Hence, consideration of EWC N-H...O H-bonds can lead to a better understanding of DNA sequence directed structural features. Copyright (c) 2006 Wiley Periodicals, Inc.

Measuring the x-ray resolving power of bent potassium acid phthalate diffraction crystals

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

Haugh, M. J., E-mail: haughmj@nv.doe.gov; Jacoby, K. D.; Wu, M.

2014-11-15

This report presents the results from measuring the X-ray resolving power of a curved potassium acid phthalate (KAP(001)) spectrometer crystal using two independent methods. It is part of a continuing effort to measure the fundamental diffraction properties of bent crystals that are used to study various characteristics of high temperature plasmas. Bent crystals like KAP(001) do not usually have the same diffraction properties as corresponding flat crystals. Models that do exist to calculate the effect of bending the crystal on the diffraction properties have simplifying assumptions and their accuracy limits have not been adequately determined. The type of crystals thatmore » we measured is being used in a spectrometer on the Z machine at Sandia National Laboratories in Albuquerque, New Mexico. The first technique for measuring the crystal resolving power measures the X-ray spectral line width of the characteristic lines from several metal anodes. The second method uses a diode X-ray source and a double crystal diffractometer arrangement to measure the reflectivity curve of the KAP(001) crystal. The width of that curve is inversely proportional to the crystal resolving power. The measurement results are analyzed and discussed.« less

True Tapping Mode Scanning Near-Field Optical Microscopy with Bent Glass Fiber Probes.

PubMed

Smirnov, A; Yasinskii, V M; Filimonenko, D S; Rostova, E; Dietler, G; Sekatskii, S K

2018-01-01

In scanning near-field optical microscopy, the most popular probes are made of sharpened glass fiber attached to a quartz tuning fork (TF) and exploiting the shear force-based feedback. The use of tapping mode feedback could be preferable. Such an approach can be realized, for example, using bent fiber probes. Detailed analysis of fiber vibration modes shows that realization of truly tapping mode of the probe dithering requires an extreme caution. In case of using the second resonance mode, probes vibrate mostly in shear force mode unless the bending radius is rather small (ca. 0.3 mm) and the probe's tip is short. Otherwise, the shear force character of the dithering persists. Probes having these characteristics were prepared by irradiation of a tapered etched glass fiber with a CW CO 2 laser. These probes were attached to the TF in double resonance conditions which enables achieving significant quality factor (4000-6000) of the TF + probe system (Cherkun et al., 2006). We also show that, to achieve a truly tapping character, dithering, short, and not exceeding 3 mm lengths of a freestanding part of bent fiber probe beam should also be used in the case of nonresonant excitation.

Measuring the x-ray resolving power of bent potassium acid phthalate diffraction crystalsa)

NASA Astrophysics Data System (ADS)

Haugh, M. J.; Wu, M.; Jacoby, K. D.; Loisel, G. P.

2014-11-01

This report presents the results from measuring the X-ray resolving power of a curved potassium acid phthalate (KAP(001)) spectrometer crystal using two independent methods. It is part of a continuing effort to measure the fundamental diffraction properties of bent crystals that are used to study various characteristics of high temperature plasmas. Bent crystals like KAP(001) do not usually have the same diffraction properties as corresponding flat crystals. Models that do exist to calculate the effect of bending the crystal on the diffraction properties have simplifying assumptions and their accuracy limits have not been adequately determined. The type of crystals that we measured is being used in a spectrometer on the Z machine at Sandia National Laboratories in Albuquerque, New Mexico. The first technique for measuring the crystal resolving power measures the X-ray spectral line width of the characteristic lines from several metal anodes. The second method uses a diode X-ray source and a double crystal diffractometer arrangement to measure the reflectivity curve of the KAP(001) crystal. The width of that curve is inversely proportional to the crystal resolving power. The measurement results are analyzed and discussed.

Filters for cathodic arc plasmas

DOEpatents

Anders, Andre; MacGill, Robert A.; Bilek, Marcela M. M.; Brown, Ian G.

2002-01-01

Cathodic arc plasmas are contaminated with macroparticles. A variety of magnetic plasma filters has been used with various success in removing the macroparticles from the plasma. An open-architecture, bent solenoid filter, with additional field coils at the filter entrance and exit, improves macroparticle filtering. In particular, a double-bent filter that is twisted out of plane forms a very compact and efficient filter. The coil turns further have a flat cross-section to promote macroparticle reflection out of the filter volume. An output conditioning system formed of an expander coil, a straightener coil, and a homogenizer, may be used with the magnetic filter for expanding the filtered plasma beam to cover a larger area of the target. A cathodic arc plasma deposition system using this filter can be used for the deposition of ultrathin amorphous hard carbon (a-C) films for the magnetic storage industry.

Day surgery for vocal fold lesions using a double-bent 60-mm Cathelin needle.

PubMed

Toyomura, Fumimasa; Tokashiki, Ryoji; Hiramatsu, Hiroyuki; Tsukahara, Kiyoaki; Motohashi, Ray; Sakurai, Eriko; Nomoto, Masaki; Suzuki, Mamoru

2014-11-01

Day surgery for vocal cord lesions overcomes the disadvantages of laryngomicrosurgery under general anesthesia. We present our experience with treatment of vocal fold lesions using a long double-bend Cathelin needle that can access all parts of the vocal cords. A 23G, 60-mm-long Cathelin needle was bent twice by 45(o) at a distance of 1 and 2 cm from the tip, and was attached to a syringe. Under topical anesthesia and nasal endoscopy of the laryngopharynx, the needle was inserted percutaneously perpendicular to the skin, the direction of insertion being altered when the bends in the needle reached the skin surface. This allows the tip of the needle to access all parts of the glottis, allowing the performance of procedures such as biopsies, excision of lesions, and injection into the vocal folds. Between January 2011 and December 2013, we used this technique to perform vocal fold procedures in 566 patients presenting for treatment of spasmodic dysphonia (412 cases, 73 %) and other vocal fold lesions. Only minor complications, such as hematoma (3 patients, 0.5 %) and slight bleeding from the puncture site in the epiglottic vallecula (all patients, 100 %), which ceased spontaneously within 10 min, were seen. Erroneous puncture occurred in three patients (0.5 %) and the puncture had to be repeated in 38 patients (6.7 %). The procedure was completed successfully in all cases (100 %). Surgery for vocal fold lesions under topical anesthesia using our double-bend Cathelin needle technique is simple, safe, and useful.

Radio active galactic nuclei in galaxy clusters: Feedback, merger signatures, and cluster tracers

NASA Astrophysics Data System (ADS)

Paterno-Mahler, Rachel Beth

Galaxy clusters, the largest gravitationally-bound structures in the universe, are composed of 50-1000s of galaxies, hot X-ray emitting gas, and dark matter. They grow in size over time through cluster and group mergers. The merger history of a cluster can be imprinted on the hot gas, known as the intracluster medium (ICM). Merger signatures include shocks, cold fronts, and sloshing of the ICM, which can form spiral structures. Some clusters host double-lobed radio sources driven by active galactic nuclei (AGN). First, I will present a study of the galaxy cluster Abell 2029, which is very relaxed on large scales and has one of the largest continuous sloshing spirals yet observed in the X-ray, extending outward approximately 400 kpc. The sloshing gas interacts with the southern lobe of the radio galaxy, causing it to bend. Energy injection from the AGN is insufficient to offset cooling. The sloshing spiral may be an important additional mechanism in preventing large amounts of gas from cooling to very low temperatures. Next, I will present a study of Abell 98, a triple system currently undergoing a merger. I will discuss the merger history, and show that it is causing a shock. The central subcluster hosts a double-lobed AGN, which is evacuating a cavity in the ICM. Understanding the physical processes that affect the ICM is important for determining the mass of clusters, which in turn affects our calculations of cosmological parameters. To further constrain these parameters, as well as models of galaxy evolution, it is important to use a large sample of galaxy clusters over a range of masses and redshifts. Bent, double-lobed radio sources can potentially act as tracers of galaxy clusters over wide ranges of these parameters. I examine how efficient bent radio sources are at tracing high-redshift (z>0.7) clusters. Out of 646 sources in our high-redshift Clusters Occupied by Bent Radio AGN (COBRA) sample, 282 are candidate new, distant clusters of galaxies based on measurements of excess galaxy counts surrounding the radio sources in Spitzer infrared images.

The visual discrimination of bending.

PubMed

Norman, J Farley; Wiesemann, Elizabeth Y; Norman, Hideko F; Taylor, M Jett; Craft, Warren D

2007-01-01

The sensitivity of observers to nonrigid bending was evaluated in two experiments. In both experiments, observers were required to discriminate on any given trial which of two bending rods was more elastic. In experiment 1, both rods bent within the same oriented plane, and bent either in a frontoparallel plane or bent in depth. In experiment 2, the two rods within any given trial bent in different, randomly chosen orientations in depth. The results of both experiments revealed that human observers are sensitive to, and can reliably detect, relatively small differences in bending (the average Weber fraction across experiments 1 and 2 was 9.0%). The performance of the human observers was compared to that of models that based their elasticity judgments upon either static projected curvature or mean and maximal projected speed. Despite the fact that all of the observers reported compelling 3-D perceptions of bending in depth, their judgments were both qualitatively and quantitatively consistent with the performance of the models. This similarity suggests that relatively straightforward information about the elasticity of simple bending objects is available in projected retinal images.

Accurate ab initio Quartic Force Fields of Cyclic and Bent HC2N Isomers

NASA Technical Reports Server (NTRS)

Inostroza, Natalia; Huang, Xinchuan; Lee, Timothy J.

2012-01-01

Highly correlated ab initio quartic force field (QFFs) are used to calculate the equilibrium structures and predict the spectroscopic parameters of three HC2N isomers. Specifically, the ground state quasilinear triplet and the lowest cyclic and bent singlet isomers are included in the present study. Extensive treatment of correlation effects were included using the singles and doubles coupled-cluster method that includes a perturbational estimate of the effects of connected triple excitations, denoted CCSD(T). Dunning s correlation-consistent basis sets cc-pVXZ, X=3,4,5, were used, and a three-point formula for extrapolation to the one-particle basis set limit was used. Core-correlation and scalar relativistic corrections were also included to yield highly accurate QFFs. The QFFs were used together with second-order perturbation theory (with proper treatment of Fermi resonances) and variational methods to solve the nuclear Schr dinger equation. The quasilinear nature of the triplet isomer is problematic, and it is concluded that a QFF is not adequate to describe properly all of the fundamental vibrational frequencies and spectroscopic constants (though some constants not dependent on the bending motion are well reproduced by perturbation theory). On the other hand, this procedure (a QFF together with either perturbation theory or variational methods) leads to highly accurate fundamental vibrational frequencies and spectroscopic constants for the cyclic and bent singlet isomers of HC2N. All three isomers possess significant dipole moments, 3.05D, 3.06D, and 1.71D, for the quasilinear triplet, the cyclic singlet, and the bent singlet isomers, respectively. It is concluded that the spectroscopic constants determined for the cyclic and bent singlet isomers are the most accurate available, and it is hoped that these will be useful in the interpretation of high-resolution astronomical observations or laboratory experiments.

Response to stem bending in forest shrubs: stem or shoot reorientation and shoot release.

PubMed

Wilson, B F

1997-10-01

Shrubs in the forest understory may be bent by their own weight or by overstory debris. To maintain height growth they must respond to bending by vertical growth of new shoots, reorientation of older axes, or by releasing preventitious buds to form epicormic shoots. I tested for these responses in Ilex verticillata L., Cornus amomum Mill., Gaylussacia baccata (Wang.) K. Koch, Viburnum cassinoides L., Hamamelis virginiana L., and Kalmia latifolia L. For each species, I removed potentially supporting vegetation adjacent to 20 stems, left 10 stems untreated to test for bending by self weight, and bent the remaining 10 stems to 45 degrees to simulate effects of fallen debris. Stem angles and curvatures were measured from before leaf out until just before leaf fall to detect either sagging from self weight or upward bending from tension wood action. Control stems initially leaned out of vertical and five of six species sagged further into a cantilever form. Several control stems failed and bent to the ground. Stems of H. virginiana, I. verticillata, and C. amomum formed tension wood, but only the first two species bent upward. Viburnum cassinoides, G. baccata, and K. latifolia formed no tension wood and sagged further down after being bent. Epicormic shoots formed with varying frequencies in all species except K. latifolia. Epicormic shoots were the major response in C. amomum, V. cassinoides, and G. baccata. New terminal shoots on bent stems recovered toward vertical in I. verticillata and K. latifolia. Negative gravitropic response of shoots was the only recovery mechanism for K. latifolia.

True Tapping Mode Scanning Near-Field Optical Microscopy with Bent Glass Fiber Probes

PubMed Central

Yasinskii, V. M.; Filimonenko, D. S.; Rostova, E.; Dietler, G.; Sekatskii, S. K.

2018-01-01

In scanning near-field optical microscopy, the most popular probes are made of sharpened glass fiber attached to a quartz tuning fork (TF) and exploiting the shear force-based feedback. The use of tapping mode feedback could be preferable. Such an approach can be realized, for example, using bent fiber probes. Detailed analysis of fiber vibration modes shows that realization of truly tapping mode of the probe dithering requires an extreme caution. In case of using the second resonance mode, probes vibrate mostly in shear force mode unless the bending radius is rather small (ca. 0.3 mm) and the probe's tip is short. Otherwise, the shear force character of the dithering persists. Probes having these characteristics were prepared by irradiation of a tapered etched glass fiber with a CW CO2 laser. These probes were attached to the TF in double resonance conditions which enables achieving significant quality factor (4000–6000) of the TF + probe system (Cherkun et al., 2006). We also show that, to achieve a truly tapping character, dithering, short, and not exceeding 3 mm lengths of a freestanding part of bent fiber probe beam should also be used in the case of nonresonant excitation. PMID:29849857

31 CFR 100.11 - Exchange of bent and partial coins.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 31 Money and Finance: Treasury 1 2011-07-01 2011-07-01 false Exchange of bent and partial coins... of bent and partial coins. (a) Definitions. (1) Bent coins are U.S. coins which are bent or deformed... readily and clearly identifiable as to genuineness and denomination. (b) Redemption basis. Bent and...

Interlocking egg-crate type grid assembly

DOEpatents

Kast, Steven J.

1987-01-01

Disclosed is an interlocking egg-crate hexagonal grid for supporting a nuclear fuel pin in a hexagonal array. The grid is formed from strips bent at an angle of about 120.degree. at each vertex. Over some faces of each hexagonal cell the strips are coplanar but are arranged, by stacking and interlocking, to avoid any double thickness of metal in that plane. Springs and dimples are formed in the faces of each cell to hold the fuel pin substantially centered.

Interlocking egg-crate type grid assembly

DOEpatents

Kast, S.J.

1985-03-15

Disclosed is an interlocking egg-crate hexagonal grid for supporting a nuclear fuel pin in a hexagonal array. The grid is formed from strips bent at an angle of about 120/sup 0/ at each vertex. Over some faces of each hexagonal cell the strips are coplanar but are arranged, by stacking interlocking, to avoid any double thickness of metal in that plane. Springs and dimples are formed in the faces of each cell to hold the fuel pin substantially centered.

Two conformational states in D-shaped DNA: Effects of local denaturation

NASA Astrophysics Data System (ADS)

Lee, O.-Chul; Kim, Cheolhee; Kim, Jae-Yeol; Lee, Nam Ki; Sung, Wokyung

2016-06-01

The bending of double-stranded(ds) DNA on the nano-meter scale plays a key role in many cellular processes such as nucleosome packing, transcription-control, and viral-genome packing. In our recent study, a nanometer-sized dsDNA bent into a D shape was formed by hybridizing a circular single-stranded(ss) DNA and a complementary linear ssDNA. Our fluorescence resonance energy transfer (FRET) measurement of D-DNA revealed two types of conformational states: a less-bent state and a kinked state, which can transform into each other. To understand the origin of the two deformed states of D-DNA, here we study the presence of open base-pairs in the ds portion by using the breathing-DNA model to simulate the system. We provide strong evidence that the two states are due to the emergence of local denaturation, i.e., a bubble in the middle and two forks at ends of the dsDNA portion. We also study the system analytically and find that the free-energy landscape is bistable with two minima representative of the two states. The kink and fork sizes estimated by the analytical calculation are also in excellent agreement with the results of the simulation. Thus, this combined experimental-simulation-analytical study corroborates that highly bent D-DNA reduces bending stress via local denaturation.

Optofluidic refractive-index sensors employing bent waveguide structures for low-cost, rapid chemical and biomedical sensing.

PubMed

Liu, I-Chen; Chen, Pin-Chuan; Chau, Lai-Kwan; Chang, Guo-En

2018-01-08

We propose and develop an intensity-detection-based refractive-index (RI) sensor for low-cost, rapid RI sensing. The sensor is composed of a polymer bent ridge waveguide (BRWG) structure on a low-cost glass substrate and is integrated with a microfluidic channel. Different-RI solutions flowing through the BRWG sensing region induce output optical power variations caused by optical bend losses, enabling simple and real-time RI detection. Additionally, the sensors are fabricated using rapid and cost-effective vacuum-less processes, attaining the low cost and high throughput required for mass production. A good RI solution of 5.31 10 -4 × RIU -1 is achieved from the RI experiments. This study demonstrates mass-producible and compact RI sensors for rapid and sensitive chemical analysis and biomedical sensing.

Bent shaft motor

DOEpatents

Benavides, Gilbert L.

1998-01-01

A nonelectromagnetic motor comprising a base, a bent shaft which is rotable relative to the base wherein the bent shaft comprises a straight portion aligned with a main axis and an offset portion that is offset with respect to the main axis; and a drive means for driving the offset portion of the bent shaft along a generally circular path in a plane perpendicular to the main axis to rotate the bent shaft. The bent shaft and drive means for driving the bent shaft can be selected from piezoelectric, magnetostrictive, rheological and shape memory alloys. The drive means of the nonelectromagnetic motor can additionally comprise a shell which shell surrounds and houses the bent shaft and precesses or gyrates which in turn causes the bent drive shaft to rotate. The nonelectromagnetic motor does not rely on friction for the application of torque upon a rotor.

Bent shaft motor

DOEpatents

Benavides, G.L.

1998-05-05

A nonelectromagnetic motor comprising a base, a bent shaft which is rotatable relative to the base wherein the bent shaft comprises a straight portion aligned with a main axis and an offset portion that is offset with respect to the main axis; and a drive means for driving the offset portion of the bent shaft along a generally circular path in a plane perpendicular to the main axis to rotate the bent shaft. The bent shaft and drive means for driving the bent shaft can be selected from piezoelectric, magnetostrictive, rheological and shape memory alloys. The drive means of the nonelectromagnetic motor can additionally comprise a shell which shell surrounds and houses the bent shaft and precesses or gyrates which in turn causes the bent drive shaft to rotate. The nonelectromagnetic motor does not rely on friction for the application of torque upon a rotor. 11 figs.

An Ab Initio Study of CuCO

NASA Technical Reports Server (NTRS)

Bauschlicher, Charles W., Jr.

1994-01-01

Modified coupled-pair functional (MCPF) calculations and coupled cluster singles and doubles calculations, which include a perturbational estimate of the connected triples [CCSD(T)], yield a bent structure for CuCO, thus, supporting the prediction of a nonlinear structure based on density functional (DF) calculations. Our best estimate for the binding energy is 4.9 +/- 1.4 kcal/mol; this is in better agreement with experiment (6.0 +/- 1.2 kcal/mol) than the DF approach which yields a value (19.6 kcal/mol) significantly larger than experiment.

The GaOH-HGaO potential energy hypersurface and the necessity of correlating the 3d electrons

NASA Astrophysics Data System (ADS)

Richards, Claude A., Jr.; Yamaguchi, Yukio; Kim, Seung-Joon; Schaefer, Henry F., III

1996-06-01

The ground state potential energy hypersurface of the GaOH-HGaO system has been investigated using high level ab initio molecular electronic structure theory. The geometries and physical properties of two equilibrium structures, one isomerization transition state and one inversion transition state were determined at the self-consistent field (SCF), configuration interaction with single and double excitations (CISD), coupled cluster with single and double excitations (CCSD), and CCSD with perturbative triple excitations [CCSD(T)] levels of theory with four sets of basis functions. It has been found that freezing the 3d electrons of the Ga atom in the correlation procedures is not appropriate for this system. For the energy difference ΔE (GaOH-HGaO) the freezing of the 3d electrons results in an error of 25 kcal/mol! The dipole moments, harmonic vibrational frequencies, and infrared (IR) intensities are predicted for the four stationary points. At the highest level of theory employed in this study, CCSD(T) using triple zeta plus double polarization with higher angular momentum and diffuse functions [TZ2P(f,d)+diff] basis set, the bent GaOH was found to be 41.9 kcal/mol more stable than the linear HGaO species; with the zero-point vibrational energy (ZPVE) correction, the energy separation becomes 40.4 kcal/mol. The classical barrier height for the exothermic isomerization (1,2 hydrogen shift) reaction HGaO→GaOH is determined to be 44.5 kcal/mol and the barrier height with the ZPVE correction 42.3 kcal/mol. The classical barrier to linearity for the bent GaOH molecule is determined to be 1.7 kcal/mol and the barrier height with the ZPVE correction to be 1.2 kcal/mol. The predicted dipole moments of GaOH and HGaO are 1.41 and 4.45 Debye, respectively. The effects of electron correlation reduce the dipole moment of HGaO by the sizable amount of 1.2 Debye. The two equilibrium species may be suitable for microwave spectroscopic investigation. Furthermore, they may also be detectable by IR techniques due to the relatively large intensities of their vibrational modes. The geometrical and energetic features are compared with those of the valence isoelectronic HXO-XOH systems, where X is a group IIIA atom and the HXO+-XOH+ systems, where X is a group IVA atom.

31 CFR 100.11 - Exchange of bent and partial coins.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false Exchange of bent and partial coins... OF PAPER CURRENCY AND COIN Exchange of Coin § 100.11 Exchange of bent and partial coins. (a) Definitions. (1) Bent coins are U.S. coins which are bent or deformed so as to preclude normal machine...

Jumbo Cutter for Removal of A Bent Femoral Interlocking Nail: A Cost Effective Method

PubMed Central

Dhanda, Manjeet Singh; Sharma, Sansar C; Ali, Nadeem; Bhat, Abedullah

2015-01-01

Closed diaphyseal femoral shaft fractures can be treated with multiple surgical options. It is more challenging to remove a bent nail than a broken one because it is difficult to retrieve the bent nail through the intramedullary canal. Various authors have published their techniques for removal of bent femoral interlocking nail. This article describes a simple technique using Jumbo cutter for sectioning and removal of bent interlocking nail. This technique will help orthopaedic surgeons to remove bent nail without using any specialised metal cutting instruments. PMID:26266173

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

Kulchin, Yurii N; Vitrik, O B; Gurbatov, S O

The phase of light propagating through a bent optical fibre is shown to depend on the refractive index of the medium surrounding the fibre cladding when there is resonance coupling between the guided core mode and cladding modes. This shifts the spectral maxima in the bent fibre-optic Fabry - Perot interferometer. The highest phase and spectral sensitivities achieved with this interferometer configuration are 0.71 and 0.077, respectively, and enable changes in the refractive index of the ambient medium down to 5 Multiplication-Sign 10{sup -6} to be detected. This makes the proposed approach potentially attractive for producing highly stable, precision refractivemore » index sensors capable of solving a wide range of liquid refractometry problems.« less

Enhancement of bending strain tolerance and current carrying property of MgB2 based multifilamentary wires

NASA Astrophysics Data System (ADS)

Thomas, Syju; Varghese, Neson; Rahul, S.; Devadas, K. M.; Vinod, K.; Syamaprasad, U.

2012-12-01

The effect of bending strain on current carrying capacity of MgB2 multifilamentary wires was studied with 4, 8 and 16 multifilamentary wires. The critical current density (JC) of straight wires and bent wires with 5, 10, and 15 cm diameter was measured. Both annealed & bent and bent & annealed wires were used for measurement. The JC of annealed & bent wires were found to decrease with decrease in bent diameter and the rate of degradation of JC decreased with increasing number of filaments, while bent & annealed wires almost retained its JC at all diameters studied.

Regulating Effect of Asymmetrical Impeller on the Flow Distributions of Double-sided Centrifugal Compressor

NASA Astrophysics Data System (ADS)

Yang, Ce; Liu, Yixiong; Yang, Dengfeng; Wang, Benjiang

2017-11-01

To achieve the rebalance of flow distributions of double-sided impellers, a method of improving the radius of rear impeller is presented in this paper. It is found that the flow distributions of front and rear impeller can be adjusted effectively by increasing the radius of rear impeller, thus improves the balance of flow distributions of front and rear impeller. Meanwhile, the working conversion mode process of double-sided centrifugal compressor is also changed. Further analysis shows that the flowrates of blade channels in front impeller are mainly influenced by the circumferential distributions of static pressure in the volute. But the flowrates of rear impeller blade channels are influenced by the outlet flow field of bent duct besides the effects of static pressure distributions in the volute. In the airflow interaction area downstream, the flowrate of blade channel is obviously smaller. By increasing the radius of rear impeller, the work capacity of rear impeller is enhanced, the working mode conversion process from parallel working mode of double-sided impeller to the single impeller working mode is delayed, and the stable working range of double-sided compressor is broadened.

Calamitic Smectic A-Polar Smectic APA Transition Observed in Bent Molecules with Large Bent-Angle Central Core of 4,6-Dichlorobenzene and Alkylthio Terminal Tail

NASA Astrophysics Data System (ADS)

Nguyen, Ha; Kang, Sungmin; Tokita, Masatoshi; Watanabe, Junji

2011-07-01

New homologs of bent molecules with a large bent-angle central core of 4,6-dichloro benzene and an alkylthio terminal tail have been synthesized. Although the corresponding alkoxy-tail homologs show only the calamitic phases because of its large bent angles around 160°, the new homologs with an alkylthio tail exhibit the antiferroelectric smectic APA (SmAPA) banana phase that is transformed on cooling from the calamitic smectic A (SmA) phase. The biaxial polar packing of bent molecules in the SmAPA phase is considered to arise from the hindered rotation around the molecular long axis due to the expansion of the mesophase temperatures to a lower temperature region. This study indicates that the bent molecules, even with a large bent angle, have the potential to form a switchable banana phase with a remarkable decrease in its phase temperature range to around 60 °C.

Fluorescent porous film modified polymer optical fiber via "click" chemistry: stable dye dispersion and trace explosive detection.

PubMed

Ma, Jiajun; Lv, Ling; Zou, Gang; Zhang, Qijin

2015-01-14

In this paper, we report a facile strategy to fabricate fluorescent porous thin film on the surface of U-bent poly(methyl methacrylate) optical fiber (U-bent POF) in situ via "click" polymerization for vapor phase sensing of explosives. Upon irradiation of evanescent UV light transmitting within the fiber under ambient condition, a porous film (POSS-thiol cross-linking film, PTCF) is synthesized on the side surface of the fiber by a thiol-ene "click" reaction of vinyl-functionalized polyhedral oligomeric silsesquioxanes (POSS-V8) and alkane dithiols. When vinyl-functionalized porphyrin, containing four allyl substituents at the periphery, is added into precursors for the polymerization, fluorescence porphyrin can be covalently bonded into the cross-linked network of PTCF. This "fastened" way reduces the aggregation-induced fluorescence self-quenching of porphyrin and enhances the physicochemical stability of the porous film on the surface of U-bent POF. Fluorescent signals of the PTCF/U-bent POF probe made by this method exhibit high fluorescence quenching toward trace TNT and DNT vapor and the highest fluorescence quenching efficiency is observed for 1, 6-hexanedimercaptan-based film. In addition, because of the presence of POSS-V8 with multi cross-linkable groups, PTCF exhibits well-organized pore network and stable dye dispersion, which not only causes fast and sensitive fluorescence quenching against vapors of nitroaromatic compounds, but also provides a repeatability of the probing performance.

Localized states in an arbitrarily bent quantum wire (bend-imitating approach)

NASA Astrophysics Data System (ADS)

Vakhnenko, Oleksity O.

1996-02-01

The bend-imitating matching technique is proposed to simplify the quantum mechanical treatment of singly and multiply bent 2D quantum wires of constant width, arbitrary bending angles, arbitrary bending radii and arbitrary distances between the bends. The spectrum of one-electron localized states and its dependence on the bending angle and the bending radius in a singly bent wire is explicitly calculated. Doubly bent wires are shown to possess doubly split localized states. The splitting energies as a function of the distance between the bends and the bending angles and bending radii have also been obtained. A similar description of bent 3D quantum wires and bent optical fibers is expected to be possible.

A possibility of parallel and anti-parallel diffraction measurements on neu- tron diffractometer employing bent perfect crystal monochromator at the monochromatic focusing condition

NASA Astrophysics Data System (ADS)

Choi, Yong Nam; Kim, Shin Ae; Kim, Sung Kyu; Kim, Sung Baek; Lee, Chang-Hee; Mikula, Pavel

2004-07-01

In a conventional diffractometer having single monochromator, only one position, parallel position, is used for the diffraction experiment (i.e. detection) because the resolution property of the other one, anti-parallel position, is very poor. However, a bent perfect crystal (BPC) monochromator at monochromatic focusing condition can provide a quite flat and equal resolution property at both parallel and anti-parallel positions and thus one can have a chance to use both sides for the diffraction experiment. From the data of the FWHM and the Delta d/d measured on three diffraction geometries (symmetric, asymmetric compression and asymmetric expansion), we can conclude that the simultaneous diffraction measurement in both parallel and anti-parallel positions can be achieved.

Magnetic-Force-Assisted Straightening of Bent Mild Steel Strip by Laser Irradiation

NASA Astrophysics Data System (ADS)

Dutta, Polash P.; Kalita, Karuna; Dixit, Uday S.; Liao, Hengcheng

2017-12-01

This study proposes a technique to straighten bent metallic strips with magnetic-force-assisted laser irradiation. Experiments were conducted for three different types of mechanically-bent mild strips. The first type was bent strips without any heat treatment. The second type was stress-relieved and third type was subcritical-annealed bent strips. These strips were straightened following different schemes of laser irradiation sequence to understand the performance of straightening. A parametric study was conducted by varying laser power and scanning speed. Micro-hardness, tensile test, Charpy impact test and microstructure after straightening were also studied. Different scanning schemes provided different microstructures and mechanical properties. Any serious deterioration in the quality of straightened strips was not noticed. Overall, subcritical-annealed bent strips provided the best performance in straightening. The proposed straightening scheme has potential of becoming an industrial practice.

Intrinsically bent DNA in replication origins and gene promoters.

PubMed

Gimenes, F; Takeda, K I; Fiorini, A; Gouveia, F S; Fernandez, M A

2008-06-24

Intrinsically bent DNA is an alternative conformation of the DNA molecule caused by the presence of dA/dT tracts, 2 to 6 bp long, in a helical turn phase DNA or with multiple intervals of 10 to 11 bp. Other than flexibility, intrinsic bending sites induce DNA curvature in particular chromosome regions such as replication origins and promoters. Intrinsically bent DNA sites are important in initiating DNA replication, and are sometimes found near to regions associated with the nuclear matrix. Many methods have been developed to localize bent sites, for example, circular permutation, computational analysis, and atomic force microscopy. This review discusses intrinsically bent DNA sites associated with replication origins and gene promoter regions in prokaryote and eukaryote cells. We also describe methods for identifying bent DNA sites for circular permutation and computational analysis.

The Nature of the Idealized Triple Bonds Between Principal Elements and the σ Origins of Trans-Bent Geometries-A Valence Bond Study.

PubMed

Ploshnik, Elina; Danovich, David; Hiberty, Philippe C; Shaik, Sason

2011-04-12

We describe herein a valence bond (VB) study of 27 triply bonded molecules of the general type X≡Y, where X and Y are main element atoms/fragments from groups 13-15 in the periodic table. The following conclusions were derived from the computational data: (a) Single π-bond and double π-bond energies for the entire set correlate with the "molecular electronegativity", which is the sum of the X and Y electronegativites for X≡Y. The correlation with the molecular electronegativity establishes a simple rule of periodicity: π-bonding strength generally increases from left to right in a period and decreases down a column in the periodic table. (b) The σ frame invariably prefers trans bending, while π-bonding gets destabilized and opposes the trans distortion. In HC≡CH, the π-bonding destabilization overrides the propensity of the σ frame to distort, while in the higher row molecules, the σ frame wins out and establishes trans-bent molecules with 2(1)/2 bonds, in accord with recent experimental evidence based on solid state (29)Si NMR of the Sekiguchi compound. Thus, in the trans-bent molecules "less bonds pay more". (c) All of the π bonds show significant bonding contributions from the resonance energy due to covalent-ionic mixing. This quantity is shown to correlate linearly with the corresponding "molecular electronegativity" and to reflect the mechanism required to satisfy the equilibrium condition for the bond. The π bonds for molecules possessing high molecular electronegativity are charge-shift bonds, wherein bonding is dominated by the resonance energy of the covalent and ionic forms, rather than by either form by itself.

Numerical analysis of lasing characteristics in highly bend-compensated large-mode-area ytterbium-doped double-clad leakage channel fibers.

PubMed

Thavasi Raja, G; Halder, Raktim; Varshney, S K

2015-12-10

The bend-induced mode-area reduction and thermal effects are vital factors that affect the power scaling of fiber lasers. Recently, bend-compensated large-mode-area double-clad modified hybrid leakage channel fiber (M-HLCF) has been reported with a mode area greater than 1000  μm, while sustaining the single-mode behavior at 1064 nm for high-temperature environments. In this work, the lasing characteristics of a newly designed ytterbium-doped double-clad M-HLCF (YDMHLCF) have been numerically investigated for strongly pumped conditions. The doped region size is optimally found through simulations, equivalent to the size of core diameter ∼38  μm in order to achieve maximum conversion efficiency for the bent and straight cases. Numerical simulations further confirm that a 2 m long YDMHLCF exhibits slope efficiency of 78% and conversion efficiency of 79% for the straight case and also almost the same for the practical bending radius of 7.5 cm when pumped with a 975 nm laser source.

Precast, Prestressed Concrete Bent Caps : Volume 2, Design Recommendations and Design Examples

DOT National Transportation Integrated Search

2018-04-01

Recommendations for design of pretensioned bent caps are developed based on the findings of full-scale experimental tests of bent cap subassemblages. Companion examples are provided to demonstrate implementation of the design recommendations. First, ...

Detection of bacteria using bacteriophage with hollow gold nanostructures immobilized fiber optic sensor

NASA Astrophysics Data System (ADS)

Halkare, Pallavi; Punjabi, Nirmal; Wangchuk, Jigme; Kondabagil, Kiran; Mukherji, Soumyo

2016-04-01

Hollow gold nanostructures (HGNS) have been used in variety of optical biosensors due to their inherent advantage of operating at near infra red (NIR) wavelength, large extinction coefficient and high dielectric sensitivity. The absorption wavelength of these nanostructures can be modulated by changing the ratio of hollow region to the core shell thickness. The aim of the present study is to incorporate the properties of HGNS, to develop LSPR based U-bent fiber optic sensor for detection of pathogens. The detection was carried out using an experimental set up consisting of a white light source, 200 μm diameter optical fiber having bend diameter of 1.6 mm +/- 0. 2 mm and a spectrometer. The HGNS were immobilized on the decladded portion of the fiber optic probe by chemisorptions. The effective plasmon penetration depth of the HGNS immobilized fiber optic sensor was approximated by using alternating layers of positively and negatively charged polyelectrolytes. The HGNS immobilized U-bent fiber optic sensor was used for detection of E.coli B40 strain using bacteriophage T4. The preliminary experiments were carried out with 104 cfu/ml of E.coli B40 and the change in absorbance obtained was approx. 0.042 +/- 0.0045 abs. units (n = 3). The response of this sensor was found to be better than spherical gold nanoparticle immobilized sensing platforms.

FIBER AND INTEGRAL OPTICS: Properties of active bent waveguides

NASA Astrophysics Data System (ADS)

Kobyl'chak, V. V.; Parygin, V. N.; Shapaev, A. G.

1989-06-01

A bent dielectric waveguide with a continuous profile of the complex refractive nc is investigated. It is shown that a negative perturbation of the real part of nc can reduce the losses in a bent waveguide. For a given radius of curvature and given parameters of the medium there is an optimal width of a planar waveguide layer for which the losses are minimal. It is shown that the properties of straight and bent waveguides of this type are different.

Bending the Curve: Sensitivity to Bending of Curved Paths and Application in Room-Scale VR.

PubMed

Langbehn, Eike; Lubos, Paul; Bruder, Gerd; Steinicke, Frank

2017-04-01

Redirected walking (RDW) promises to allow near-natural walking in an infinitely large virtual environment (VE) by subtle manipulations of the virtual camera. Previous experiments analyzed the human sensitivity to RDW manipulations by focusing on the worst-case scenario, in which users walk perfectly straight ahead in the VE, whereas they are redirected on a circular path in the real world. The results showed that a physical radius of at least 22 meters is required for undetectable RDW. However, users do not always walk exactly straight in a VE. So far, it has not been investigated how much a physical path can be bent in situations in which users walk a virtual curved path instead of a straight one. Such curved walking paths can be often observed, for example, when users walk on virtual trails, through bent corridors, or when circling around obstacles. In such situations the question is not, whether or not the physical path can be bent, but how much the bending of the physical path may vary from the bending of the virtual path. In this article, we analyze this question and present redirection by means of bending gains that describe the discrepancy between the bending of curved paths in the real and virtual environment. Furthermore, we report the psychophysical experiments in which we analyzed the human sensitivity to these gains. The results reveal encouragingly wider detection thresholds than for straightforward walking. Based on our findings, we discuss the potential of curved walking and present a first approach to leverage bent paths in a way that can provide undetectable RDW manipulations even in room-scale VR.

Non-astigmatic imaging with matched pairs of spherically bent reflectors

DOEpatents

Bitter, Manfred Ludwig [Princeton, NJ; Hill, Kenneth Wayne [Plainsboro, NJ; Scott, Steven Douglas [Wellesley, MA; Feder, Russell [Newton, PA; Ko, Jinseok [Cambridge, MA; Rice, John E [N. Billerica, MA; Ince-Cushman, Alexander Charles [New York, NY; Jones, Frank [Manalapan, NJ

2012-07-10

Arrangements for the point-to-point imaging of a broad spectrum of electromagnetic radiation and ultrasound at large angles of incidence employ matched pairs of spherically bent reflectors to eliminate astigmatic imaging errors. Matched pairs of spherically bent crystals or spherically bent multi-layers are used for X-rays and EUV radiation; and matched pairs of spherically bent mirrors that are appropriate for the type of radiation are used with microwaves, infrared and visible light, or ultrasound. The arrangements encompass the two cases, where the Bragg angle--the complement to the angle of incidence in optics--is between 45.degree. and 90.degree. on both crystals/mirrors or between 0.degree. and 45.degree. on the first crystal/mirror and between 45.degree. and 90.degree. on the second crystal/mirror, where the angles of convergence and divergence are equal. For x-rays and EUV radiation, also the Bragg condition is satisfied on both spherically bent crystals/multi-layers.

Repair of Morganza Spillway Bridge bent pile cap using carbon fiber reinforcement (CFR) : tech summary.

DOT National Transportation Integrated Search

2016-04-01

The pile cap of an end bent of the Morganza Spillway Bridge suffered extensive damage at the girder bearing locations, particularly on the side where the pounding of the girders by the adjacent concrete deck located on the approach side of the bent. ...

Analysis of residual stress and hardness in regions of pre-manufactured and manual bends in fixation plates for maxillary advancement.

PubMed

Araújo, Marcelo Marotta; Lauria, Andrezza; Mendes, Marcelo Breno Meneses; Claro, Ana Paula Rosifini Alves; Claro, Cristiane Aparecida de Assis; Moreira, Roger William Fernandes

2015-12-01

The aim of this study was to analyze, through Vickers hardness test and photoelasticity analysis, pre-bent areas, manually bent areas, and areas without bends of 10-mm advancement pre-bent titanium plates (Leibinger system). The work was divided into three groups: group I-region without bend, group II-region of 90° manual bend, and group III-region of 90° pre-fabricated bends. All the materials were evaluated through hardness analysis by the Vickers hardness test, stress analysis by residual images obtained in a polariscope, and photoelastic analysis by reflection during the manual bending. The data obtained from the hardness tests were statistically analyzed using ANOVA and Tukey's tests at a significance level of 5 %. The pre-bent plate (group III) showed hardness means statistically significantly higher (P < 0.05) than those of the other groups (I-region without bends, II-90° manually bent region). Through the study of photoelastic reflection, it was possible to identify that the stress gradually increased, reaching a pink color (1.81 δ / λ), as the bending was performed. A general analysis of the results showed that the bent plate region of pre-bent titanium presented the best results.

The energetics of tightly bent DNA: a composite elastica model including local melting

NASA Astrophysics Data System (ADS)

Evans, Arthur; Levine, Alex

2012-02-01

Melting transitions are well-known to be affected by the application of mechanical stress. Motivated by the experiments of Zocchi and collaborators (Qu and Zocchi 2011, EPL 94 18003), we explore the effect of the application of mechanical stress on DNA melting in a particular composite of a stiff double stranded piece of DNA (dsDNA), shorter than its own persistence length, whose ends are linked by a flexible single stranded piece of DNA (ssDNA). The flexible ssDNA acts as a Gaussian polymer coil bending the stiff dsDNA through an elastic force that is controllable by the length of the ssDNA chain. In this talk we present theoretical predictions for two experimentally accessible features: the degree of local dsDNA melting and the local elastic energy of the dsDNA/ssDNA construct both as a function of the length of the attached ssDNA. We also address the effect of introducing a nick (broken covalent bond) in the dsDNA backbone on these results and discuss the implications of such data on the relative importance of backbone elasticity versus base stacking and base pairing interactions in determining the elasticity of dsDNA. This work also addresses open questions in the nonlinear elasticity of DNA in tightly bent curves.

Spatiotemporal character of the Bobylev-Pikin flexoelectric instability in a twisted nematic bent-core liquid crystal exposed to very low frequency fields.

PubMed

Krishnamurthy, K S

2014-05-01

The Bobylev-Pikin striped-pattern state induced by a homogeneous electric field is a volume flexoelectric instability, originating in the midregion of a planarly aligned nematic liquid crystal layer. We find that the instability acquires a spatiotemporal character upon excitation by a low frequency (0.5 Hz) square wave field. This is demonstrated using a bent-core liquid crystal, initially in the 90°-twisted planar configuration. The flexoelectric modulation appears close to the cathode at each polarity reversal and, at low voltage amplitudes, decays completely as the field becomes steady. Correspondingly, at successive polarity changes, the stripe direction switches between the alignment directions at the two substrates. For large voltages, the stripes formed nearly along the alignment direction at the cathode gradually reorient toward the midplane director. These observations are generally attributed to inhomogeneous and time-dependent field conditions that come to exist after each polarity reversal. Polarity dependence of the instability is attributed to the formation of intrinsic double layers that bring about an asymmetry in surface fields. Momentary field elevation near the cathode following a voltage sign reversal and concomitant gradient flexoelectric polarization are considered the key factors in accounting for the surfacelike modulation observed at low voltages.

Silky bent grass resistance to herbicides: one year of monitoring in Belgium.

PubMed

Henriet, F; Bodson, B; Morales, R Meza

2013-01-01

Silky bent grass (Apera spica-venti (L.) P. Beauv.) is a common weed of cereal crops widely spread in Northern and Easthern Europe (Germany, Czech Republic,...), Northern Asia, Siberia and Canada. Up to now, no resistant case has been detected in Belgium but some chemical weeding failures have been observed in Wallonia fields. During summer 2011, 37 seed samples of Apera spica-venti were collected in Wallonia and submitted to resistance tests in controlled conditions. Three modes of action were tested: acetyl coenzyme-A carboxylase inhibitors (pinoxaden and cycloxydim), acetolactate synthase inhibitors (mesosulfuron+iodosulfu-ron, pyroxsulam and sulfometuron) and photosynthesis inhibitors (isoproturon). One susceptible standard population was included in the test in order to validate it and to permit wild populations classification according to "R" rating system developed by Moss et al (2007). Most of populations were susceptible but some populations showed resistance to at least one of the three tested modes of action.

Unusual polarity-dependent patterns in a bent-core nematic liquid crystal under low-frequency ac field.

PubMed

Xiang, Ying; Zhou, Meng-jie; Xu, Ming-Ya; Salamon, Péter; Éber, Nándor; Buka, Ágnes

2015-04-01

Electric-field-induced patterns of diverse morphology have been observed over a wide frequency range in a recently synthesized bent-core nematic (BCN) liquid crystal. At low frequencies (up to ∼25 Hz), the BCN exhibited unusual polarity-dependent patterns. When the amplitude of the ac field was enhanced, these two time-asymmetrical patterns turned into time-symmetrical prewavylike stripes. At ac frequencies in the middle-frequency range (∼50-3000 Hz), zigzag patterns were detected whose obliqueness varied with the frequency. Finally, if the frequency was increased above 3 kHz, the zigzag pattern was replaced by another, prewavylike pattern, whose threshold voltage depended on the frequency; however, the wave vector did not. For a more complete characterization, material parameters such as elastic constants, dielectric permittivities, and the anisotropy of the diamagnetic susceptibility were also determined.

Classifying bent radio galaxies from a mixture of point-like/extended images with Machine Learning.

NASA Astrophysics Data System (ADS)

Bastien, David; Oozeer, Nadeem; Somanah, Radhakrishna

2017-05-01

The hypothesis that bent radio sources are supposed to be found in rich, massive galaxy clusters and the avalibility of huge amount of data from radio surveys have fueled our motivation to use Machine Learning (ML) to identify bent radio sources and as such use them as tracers for galaxy clusters. The shapelet analysis allowed us to decompose radio images into 256 features that could be fed into the ML algorithm. Additionally, ideas from the field of neuro-psychology helped us to consider training the machine to identify bent galaxies at different orientations. From our analysis, we found that the Random Forest algorithm was the most effective with an accuracy rate of 92% for a classification of point and extended sources as well as an accuracy of 80% for bent and unbent classification.

Ground and excited states of vanadium hydroxide isomers and their cations, VOH0,+ and HVO0,+

NASA Astrophysics Data System (ADS)

Miliordos, Evangelos; Harrison, James F.; Hunt, Katharine L. C.

2013-03-01

Employing correlation consistent basis sets of quadruple-zeta quality and applying both multireference configuration interaction and single-reference coupled cluster methodologies, we studied the electronic and geometrical structure of the [V,O,H]0,+ species. The electronic structure of HVO0,+ is explained by considering a hydrogen atom approaching VO0,+, while VOH0,+ molecules are viewed in terms of the interaction of V+,2+ with OH-. The potential energy curves for H-VO0,+ and V0,+-OH have been constructed as functions of the distance between the interacting subunits, and the potential energy curves have also been determined as functions of the H-V-O angle. For the stationary points that we have located, we report energies, geometries, harmonic frequencies, and dipole moments. We find that the most stable bent HVO0,+ structure is lower in energy than any of the linear HVO0,+ structures. Similarly, the most stable state of bent VOH is lower in energy than the linear structures, but linear VOH+ is lower in energy than bent VOH+. The global minimum on the potential energy surface for the neutral species is the tilde{X}^3A″ state of bent HVO, although the tilde{X}^5A″ state of bent VOH is less than 5 kcal/mol higher in energy. The global minimum on the potential surface for the cation is the tilde{X}^4Σ ^- state of linear VOH+, with bent VOH+ and bent HVO+ both more than 10 kcal/mol higher in energy. For the neutral species, the bent geometries exhibit significantly higher dipole moments than the linear structures.

The incidence of bent dorsal fins in free-ranging cetaceans.

PubMed

Alves, F; Towers, J R; Baird, R W; Bearzi, G; Bonizzoni, S; Ferreira, R; Halicka, Z; Alessandrini, A; Kopelman, A H; Yzoard, C; Rasmussen, M H; Bertulli, C G; Jourdain, E; Gullan, A; Rocha, D; Hupman, K; Mrusczok, M-T; Samarra, F I P; Magalhães, S; Weir, C R; Ford, J K B; Dinis, A

2018-02-01

Laterally bent dorsal fins are rarely observed in free-ranging populations of cetaceans, contrary to captivity, where most killer whale Orcinus orca adult males have laterally collapsed fins. This topic has been poorly explored, and data/information on its occurrence and possible causes are limited. The present study: (i) undertakes a review of the available information on bent dorsal fins in free-ranging cetaceans, and updates it with new records, (ii) reports on the proportion of bent fins in different study populations, and (iii) discusses possible causes. An empirical approach based on bibliographic research and compilation of 52 new records collected worldwide resulted in a total of 17 species of cetaceans displaying bent dorsal fins. The species with the highest number of records (64%) and from most locations was O. orca. On average, individuals with bent dorsal fins represent < 1% of their populations, with the exception of false killer whales Pseudorca crassidens and O. orca. While line injuries associated with fisheries interactions may be the main cause for P. crassidens, and the vulnerability to health issues caused by the evolutionary enlargement of the fin may be the cause for O. orca adult males, factors contributing to this abnormality for other species are still unclear. The occurrence of bent dorsals could be influenced by a set of variables rather than by a single factor but, irrespective of the cause, it is suggested that it does not directly affect the animals' survivorship. While still rare in nature, this incident is more common (at least 101 known cases) and widespread (geographically and in species diversity) than hypothesized, and is not confined only to animals in captive environments. Investigation into the occurrence of bent fins may be an interesting avenue of research. © 2017 Anatomical Society.

Analysis of Structural Flexibility of Damaged DNA Using Thiol-Tethered Oligonucleotide Duplexes

PubMed Central

Fujita, Masashi; Watanabe, Shun; Yoshizawa, Mariko; Yamamoto, Junpei; Iwai, Shigenori

2015-01-01

Bent structures are formed in DNA by the binding of small molecules or proteins. We developed a chemical method to detect bent DNA structures. Oligonucleotide duplexes in which two mercaptoalkyl groups were attached to the positions facing each other across the major groove were prepared. When the duplex contained the cisplatin adduct, which was proved to induce static helix bending, interstrand disulfide bond formation under an oxygen atmosphere was detected by HPLC analyses, but not in the non-adducted duplex, when the two thiol-tethered nucleosides were separated by six base pairs. When the insert was five and seven base pairs, the disulfide bond was formed and was not formed, respectively, regardless of the cisplatin adduct formation. The same reaction was observed in the duplexes containing an abasic site analog and the (6–4) photoproduct. Compared with the cisplatin case, the disulfide bond formation was slower in these duplexes, but the reaction rate was nearly independent of the linker length. These results indicate that dynamic structural changes of the abasic site- and (6–4) photoproduct-containing duplexes could be detected by our method. It is strongly suggested that the UV-damaged DNA-binding protein, which specifically binds these duplexes and functions at the first step of global-genome nucleotide excision repair, recognizes the easily bendable nature of damaged DNA. PMID:25679955

Technology transfer: taking science from the books to the ground at Bent Creek Experimental Forest

Treesearch

Julia Kirschman

2014-01-01

Technology transfer has been an important part of the research program at Bent Creek Experimental Forest (Bent Creek) since its establishment in 1925. Our stated mission is to develop and disseminate knowledge and strategies for restoring, managing, sustaining, and enhancing the vegetation and wildlife of upland hardwood-dominated forest ecosystems of the Southern...

Spherical tensor analysis of polar liquid crystals with biaxial and chiral molecules

NASA Astrophysics Data System (ADS)

Iwamoto, Mitsumasa; Zhong-can, Ou-Yang

2012-11-01

With the help of spherical tensor expression, an irreducible calculus of a Lth-rank macroscopic susceptibility χ for a polar liquid crystal (PLC) of biaxial and chiral molecules written as the average of molecular hyperpolarizability tensor β associated with their spherical orientational order parameters (0⩽l⩽L) is presented. Comprehensive formulas of L=1,2 have been obtained and the latter explains the optical activity and spontaneous splay texture observed in bent-core PLC. The expression of L=3 specifies for the molecules with D2 symmetry which can be applied to analyze the nonlinear optical second harmonic generation (SHG) observed in proteins, peptides, and double-stranded DNA at interfaces.

Recent developments for the Large Binocular Telescope Guiding Control Subsystem

NASA Astrophysics Data System (ADS)

Golota, T.; De La Peña, M. D.; Biddick, C.; Lesser, M.; Leibold, T.; Miller, D.; Meeks, R.; Hahn, T.; Storm, J.; Sargent, T.; Summers, D.; Hill, J.; Kraus, J.; Hooper, S.; Fisher, D.

2014-07-01

The Large Binocular Telescope (LBT) has eight Acquisition, Guiding, and wavefront Sensing Units (AGw units). They provide guiding and wavefront sensing capability at eight different locations at both direct and bent Gregorian focal stations. Recent additions of focal stations for PEPSI and MODS instruments doubled the number of focal stations in use including respective motion, camera controller server computers, and software infrastructure communicating with Guiding Control Subsystem (GCS). This paper describes the improvements made to the LBT GCS and explains how these changes have led to better maintainability and contributed to increased reliability. This paper also discusses the current GCS status and reviews potential upgrades to further improve its performance.

Bent's Old Fort: Amphibians and Reptiles

USGS Publications Warehouse

Muths, E.

2008-01-01

Bent's Old Fort National Historic Site sits along the Arkansas River in the semi-desert prairie of southeastern Colorado. The USGS provided assistance in designing surveys to assess the variety of herpetofauna (amphibians and reptiles) resident at this site. This brochure is the results of those efforts and provides visitors with information on what frogs, toads, snakes and salamanders might be seen and heard at Bent's Old Fort.

Further Results on Constructions of Generalized Bent Boolean Functions

DTIC Science & Technology

2016-03-01

China; 2Naval Postgraduate School, Applied Mathematics Department, Monterey, CA 93943, USA; 3Science and Technology on Communication Security...in 1976 as an interesting combinatorial object with the important property of having op- timal nonlinearity [1]. Since bent functions have many...77–94 10 Zhao Y, Li H L. On bent functions with some symmet- ric properties. Discret Appl Math, 2006, 154: 2537– 2543

Approach to a manufacture-oriented modeling of bent tubes depending on the curvature distribution during three-roll-push-bending

NASA Astrophysics Data System (ADS)

Groth, Sebastian; Engel, Bernd; Frohn, Peter

2018-05-01

Kinematic bending processes such as three-roll-push-bending are used to manufacture freeform bent part systems. Due to the kinematic shaping, the bent parts have a characteristic infeed and outfeed area in the transition zone from the straight section into the curved area. These transition zones are currently not considered in the design process, which results in a geometric shape deviation between the CAD model and the bent part. Within this publication, a sensitivity analysis examines the influence of different parameters on the transition zone and the shape deviation. In addition, an approach is presented, which allows a manufacture-oriented modeling of the bending geometry.

Channeling through Bent Crystals

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

Mack, Stephanie; /Ottawa U. /SLAC

2012-09-07

Bent crystals have demonstrated potential for use in beam collimation. A process called channeling is when accelerated particle beams are trapped by the nuclear potentials in the atomic planes within a crystal lattice. If the crystal is bent then the particles can follow the bending angle of the crystal. There are several different effects that are observed when particles travel through a bent crystal including dechanneling, volume capture, volume reflection and channeling. With a crystal placed at the edge of a particle beam, part of the fringe of the beam can be deflected away towards a detector or beam dump,more » thus helping collimate the beam. There is currently FORTRAN code by Igor Yazynin that has been used to model the passage of particles through a bent crystal. Using this code, the effects mentioned were explored for beam energy that would be seen at the Facility for Advanced Accelerator Experimental Tests (FACET) at a range of crystal orientations with respect to the incoming beam. After propagating 5 meters in vacuum space past the crystal the channeled particles were observed to separate from most of the beam with some noise due to dechanneled particles. Progressively smaller bending radii, with corresponding shorter crystal lengths, were compared and it was seen that multiple scattering decreases with the length of the crystal therefore allowing for cleaner detection of the channeled particles. The input beam was then modified and only a portion of the beam sent through the crystal. With the majority of the beam not affected by the crystal, most particles were not deflected and after propagation the channeled particles were seen to be deflected approximately 5mm. After a portion of the beam travels through the crystal, the entire beam was then sent through a quadrupole magnet, which increased the separation of the channeled particles from the remainder of the beam to a distance of around 20mm. A different code, which was developed at SLAC, was used to create an angular profile plot which was compared to what was produced by Yazynin's code for a beam with no multiple scattering. The results were comparable, with volume reflection and channeling effects observed and the range of crystal orientations at which volume reflection is seen was about 1 mrad in both simulations.« less

Preparation, Characterization, and In Vitro Testing of Nanoclay Antimicrobial Activities and Elicitor Capacity.

PubMed

Merino, Danila; Mansilla, Andrea Y; Casalongué, Claudia A; Alvarez, Vera A

2018-03-28

Clay-based nanocomposites (nanoclays) are interesting systems to hold a wide type of active substances with a wide field of industrial applications. Bentonite-chitosan nanoclay was obtained via cationic exchange of natural bentonite (Bent) with an aqueous solution of chitosan (CS). Their physicochemical and morphological properties were discussed under the light of Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, and scanning electron microscopy. Bent-CS characterization indicated that CS was intercalated in 10% (w/w). This polycationic polymer was oriented mostly in a monolayer arrangement, interacting by electrostatic forces between Bent sheets. The antimicrobial action of Bent-CS nanoclay was assayed onto phytopathogens, the bacterium model Pseudomonas syringe pv. tomato DC3000 ( Psy) and the necrotrophic fungus Fusarium solani f. sp. eumartii ( F. eumartii). In addition to demonstrating cell death on both microorganisms, Bent-CS exerted elicitor property on tomato plantlets. The biological actions of this natural nanomaterial might make it proper to be used in crops.

The Signs B [Image Omitted] and B-Bent [Image Omitted] in Israeli Sign Language According to the Theory of Phonology as Human Behavior

ERIC Educational Resources Information Center

Fuks, Orit; Tobin, Yishai

2008-01-01

The purpose of the present research is to examine which of the two factors: (1) the iconic-semiotic factor; or (2) the human-phonetic factor is more relevant in explaining the appearance and distribution of the hand shape B-bent in Israeli Sign Language (ISL). The B-bent shape has been the subject of much attention in sign language research…

Ion implantation for manufacturing bent and periodically bent crystals

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

Bellucci, Valerio; Camattari, Riccardo; Guidi, Vincenzo, E-mail: guidi@fe.infn.it

2015-08-10

Ion implantation is proposed to produce self-standing bent monocrystals. A Si sample 0.2 mm thick was bent to a radius of curvature of 10.5 m. The sample curvature was characterized by interferometric measurements; the crystalline quality of the bulk was tested by X-ray diffraction in transmission geometry through synchrotron light at ESRF (Grenoble, France). Dislocations induced by ion implantation affect only a very superficial layer of the sample, namely, the damaged region is confined in a layer 1 μm thick. Finally, an elective application of a deformed crystal through ion implantation is here proposed, i.e., the realization of a crystalline undulator to producemore » X-ray beams.« less

Many-body quantum dynamics in the decay of bent dark solitons of Bose-Einstein condensates

NASA Astrophysics Data System (ADS)

Katsimiga, G. C.; Mistakidis, S. I.; Koutentakis, G. M.; Kevrekidis, P. G.; Schmelcher, P.

2017-12-01

The beyond mean-field (MF) dynamics of a bent dark soliton (BDS) embedded in a two-dimensional repulsively interacting Bose-Einstein condensate is explored. We examine the case of a single BDS comparing the MF dynamics to a correlated approach, the multi-configuration time-dependent Hartree method for bosons. Dynamical snaking of this bent structure is observed, signaling the onset of fragmentation which becomes significant during the vortex nucleation. In contrast to the MF approximation ‘filling’ of the vortex core is observed, leading in turn to the formation of filled-core vortices, instead of the MF vortex-antivortex pairs. The resulting smearing effect in the density is a rather generic feature, occurring when solitonic structures are exposed to quantum fluctuations. Here, we show that this filling owes its existence to the dynamical building of an antidark structure developed in the next-to-leading order orbital. We further demonstrate that the aforementioned beyond MF dynamics can be experimentally detected using the variance of single shot measurements. Additionally, a variety of excitations including vortices, oblique dark solitons, and open ring dark soliton-like structures building upon higher-lying orbitals is observed. We demonstrate that signatures of the higher-lying orbital excitations emerge in the total density, and can be clearly captured by inspecting the one-body coherence. In the latter context, the localization of one-body correlations exposes the existence of the multi-orbital vortex-antidark structure.

Novel ultra-short and ultra-broadband polarization beam splitter based on a bent directional coupler.

PubMed

Dai, Daoxin; Bowers, John E

2011-09-12

A novel ultra-short polarization beam splitter (PBS) based on a bent directional coupler is proposed by utilizing the evanescent coupling between two bent optical waveguides with different core widths. For the bent directional coupler, there is a significant phase-mismatch for TE polarization while the phase-matching condition is satisfied for TM polarization. Therefore, the TM polarized light can be coupled from the narrow input waveguide to the adjacent wide waveguide while the TE polarization goes through the coupling region without significant coupling. An ultra-short (<10 μm-long) PBS is designed based on silicon-on-insulator nanowires and the length of the bent coupling region is as small as 4.5 μm while the gap width is chosen as 200 nm (large enough to simplify the fabrication). Numerical simulations show that the present PBS has a good fabrication tolerance for the variation of the waveguide width (more than ± 60 nm) and a very broad band (~200 nm) for an extinction ratio of >10 dB.

From the molecular structure to spectroscopic and material properties: computational investigation of a bent-core nematic liquid crystal.

PubMed

Greco, Cristina; Marini, Alberto; Frezza, Elisa; Ferrarini, Alberta

2014-05-19

We present a computational investigation of the nematic phase of the bent-core liquid crystal A131. We use an integrated approach that bridges density functional theory calculations of molecular geometry and torsional potentials to elastic properties through the molecular conformational and orientational distribution function. This unique capability to simultaneously access different length scales enables us to consistently describe molecular and material properties. We can reassign (13)C NMR chemical shifts and analyze the dependence of phase properties on molecular shape. Focusing on the elastic constants we can draw some general conclusions on the unconventional behavior of bent-core nematics and highlight the crucial role of a properly-bent shape. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Recent progress on the mechanics of sharply bent DNA

NASA Astrophysics Data System (ADS)

Cong, PeiWen; Yan, Jie

2016-08-01

Despite extensive studies on the mechanics of DNA under external constrains, such as tension, torsion, and bending, several important aspects have remained poorly understood. One biologically important example is the mechanics of DNA under sharp bending conditions, which has been debated for a decade without thorough comprehension. The debate is about the interesting phenomenon raised from a series of different experiments: sharply bent DNA has a surprisingly high apparent bending flexibility that deviates from the canonical bending elasticity of DNA. This finding has motivated various theoretical models, which mainly incorporate the excitation of mechanical defects inside severely bent DNA molecules. Here, we review the recent progress on the understanding of the mechanics of sharply bent DNA and provide our view on this important question by interrogating the theoretical foundation of these experimental measurements.

Mathematical modeling of bent-axis hydraulic piston motors

NASA Technical Reports Server (NTRS)

Bartos, R. D.

1992-01-01

Each of the DSN 70-m antennas uses 16 bent-axis hydraulic piston motors as part of the antenna drive system. On each of the two antenna axes, four motors are used to drive the antenna and four motors provide counter torque to remove the backlash in the antenna drive train. This article presents a mathematical model for bent-axis hydraulic piston motors. The model was developed to understand the influence of the hydraulic motors on the performance of the DSN 70-m antennas' servo control system.

Transnasal Endoscope Locked in a Bent Position Causing Difficult Withdrawal

PubMed Central

Kumada, Takashi; Hisanaga, Yasuhiro

2014-01-01

We report a rare but severe complication of routine transnasal esophagogastroduodenoscopy (EGD). The tip of a transnasal endoscope was locked in a bent position. Since the bent tip was unable to be returned to a neutral position, the snare from another endoscope inserted transorally was used to straighten it, which allowed the transnasal endoscope to be withdrawn with only mild injury to the gastric mucosa. Endoscopists should be aware of this complication and how to manage it. PMID:26157831

49 CFR Appendix A to Part 231 - Schedule of Civil Penalties 1

Code of Federal Regulations, 2011 CFR

2011-10-01

... 120.B1Brake Step or Brace Bent 2,500 5,000 120.B2Brake Step or Wrong Dimensions 2,500 5,000 120...,000 124.B1Running Board Bent to the Extent that It is Unsafe 2,500 5,000 124.B2Running Board Wrong... 126.B1End Platform or Brace Bent 2,500 5,000 126.B2End Platform Wrong Dimensions 2,500 5,000 126.C1End...

How a short double-stranded DNA bends

NASA Astrophysics Data System (ADS)

Shin, Jaeoh; Lee, O.-Chul; Sung, Wokyung

2015-04-01

A recent experiment using fluorescence microscopy showed that double-stranded DNA fragments shorter than 100 base pairs loop with the probabilities higher by the factor of 102-106 than predicted by the worm-like chain (WLC) model [R. Vafabakhsh and T. Ha, Science 337, 1101(2012)]. Furthermore, the looping probabilities were found to be nearly independent of the loop size. The results signify a breakdown of the WLC model for DNA mechanics which works well on long length scales and calls for fundamental understanding for stressed DNA on shorter length scales. We develop an analytical, statistical mechanical model to investigate what emerges to the short DNA under a tight bending. A bending above a critical level initiates nucleation of a thermally induced bubble, which could be trapped for a long time, in contrast to the bubbles in both free and uniformly bent DNAs, which are either transient or unstable. The trapped bubble is none other than the previously hypothesized kink, which releases the bending energy more easily as the contour length decreases. It leads to tremendous enhancement of the cyclization probabilities, in a reasonable agreement with experiment.

Propagation of polarised light in bent hi-bi spun fibres

NASA Astrophysics Data System (ADS)

Przhiyalkovsky, Ya V.; Morshnev, S. K.; Starostin, N. I.; Gubin, V. P.

2015-11-01

The evolution of polarisation states (PS's) of broadband light propagating through a bent optical fibre with a helical structure of its refractive index anisotropy (hi-bi spun fibre) has been studied theoretically and experimentally. It has been shown that there exists a coordinate system of PS's in which the differential Jones matrix can be replaced by a diagonal matrix, which allows the polarisation parameters of the output broadband light to be readily calculated with sufficient accuracy. We have derived a formula for evaluating the magneto-optical sensitivity of a bent spun fibre. An approach has been proposed for restoring the degree of polarisation of light in a bent hi-bi spun fibre and, as a consequence, the visibility (contrast) of the interferometer in a current sensor with a sensing element based on the fibre under consideration.

Bend-imitating models of abruptly bent electron waveguides

NASA Astrophysics Data System (ADS)

Vakhnenko, Oleksiy O.

2011-07-01

The fundamentals of bend-imitating approach regarding the one-electron quantum mechanics in abruptly bent ideal electron waveguides are given. In general, the theory allows to model each particular circularlike bend of a continuous quantum wire as some effective multichannel scatterer being pointlike in longitudinal direction. Its scattering ability is determined by the bending angle, mean bending radius, lateral coordinate (or coordinates) in wire cross section, time (or electronic energy), and possibly by the applied magnetic field. In an equivalent formulation, the theory gives rise to rather simple matching rules for the electron wave function and its longitudinal derivative affecting only the straight parts of a wire and thereby permitting to bypass a detailed quantum mechanical consideration of elbow domains. The proposed technique is applicable for the analytical investigation of spectral and transport electronic properties related to the ideal abruptly bent 3D wirelike structures of fixed cross section and is adaptable to the 2D wirelike structures as well as to the wirelike structures subjected to the magnetic field perpendicular to the plane of wire bending. In the framework of bend-imitating approach, the investigation of electron scattering in a singly bent 2D quantum wire and a doubly bent 2D quantum wire with S-like bend has been made and the explicit dependences of transmission and reflection coefficients on geometrical parameters of respective structure as well as on electron energy have been obtained. The total suppression of mixing between the scattering channels of S-like bent quantum wire is predicted.

The Free Energy Profile of Tubulin Straight-Bent Conformational Changes, with Implications for Microtubule Assembly and Drug Discovery

PubMed Central

Bonomi, Massimiliano; Agard, David A.; Jacobson, Matthew P.

2014-01-01

αβ-tubulin dimers need to convert between a ‘bent’ conformation observed for free dimers in solution and a ‘straight’ conformation required for incorporation into the microtubule lattice. Here, we investigate the free energy landscape of αβ-tubulin using molecular dynamics simulations, emphasizing implications for models of assembly, and modulation of the conformational landscape by colchicine, a tubulin-binding drug that inhibits microtubule polymerization. Specifically, we performed molecular dynamics, potential-of-mean force simulations to obtain the free energy profile for unpolymerized GDP-bound tubulin as a function of the ∼12° intradimer rotation differentiating the straight and bent conformers. Our results predict that the unassembled GDP-tubulin heterodimer exists in a continuum of conformations ranging between straight and bent, but, in agreement with existing structural data, suggests that an intermediate bent state has a lower free energy (by ∼1 kcal/mol) and thus dominates in solution. In agreement with predictions of the lattice model of microtubule assembly, lateral binding of two αβ-tubulins strongly shifts the conformational equilibrium towards the straight state, which is then ∼1 kcal/mol lower in free energy than the bent state. Finally, calculations of colchicine binding to a single αβ-tubulin dimer strongly shifts the equilibrium toward the bent states, and disfavors the straight state to the extent that it is no longer thermodynamically populated. PMID:24516374

Replication origins oriGNAI3 and oriB of the mammalian AMPD2 locus nested in a region of straight DNA flanked by intrinsically bent DNA sites.

PubMed

Balani, Valério Américo; de Lima Neto, Quirino Alves; Takeda, Karen Izumi; Gimenes, Fabrícia; Fiorini, Adriana; Debatisse, Michelle; Fernandez, Maria Aparecida

2010-11-01

The aim of this work was to determine whether intrinsically bent DNA sites are present at, or close to, the mammalian replication origins oriGNAI3 and oriB in the Chinese hamster AMPD2 locus. Using an electrophoretic mobility shift assay and in silico analysis, we located four intrinsically bent DNA sites (b1 to b4) in a fragment that contains the oriGNAI3 and one site (b5) proximal to oriB. The helical parameters show that each bent DNA site is curved in a left-handed superhelical writhe. A 2D projection of 3D fragment trajectories revealed that oriGNAI3 is located in a relatively straight segment flanked by bent sites b1 and b2, which map in previously identified Scaffold/Matrix Attachment Region. Sites b3 and b4 are located approximately 2 kb downstream and force the fragment into a strong closed loop structure. The b5 site is also located in an S/MAR that is found just downstream of oriB.

Behavior of micropiles in bridge bent applications.

DOT National Transportation Integrated Search

2010-12-01

This project concerned the behavior of micropiles under lateral loads. The North Carolina Department of Transportation was specifically interested in the use of micropiles to support bridge bents. In this configuration micropiles would be subjected t...

35. DETAIL VIEW OF GUNITEENCASED CONCRETE PILINGS AT BENT 6, ...

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

35. DETAIL VIEW OF GUNITE-ENCASED CONCRETE PILINGS AT BENT 6, LOOKING SOUTHWEST (CAMERA AGAINST CHAIN-LINK FENCE) - Huntington Beach Municipal Pier, Pacific Coast Highway at Main Street, Huntington Beach, Orange County, CA

Shuttle Ku-band bent-pipe implementation considerations. [for Space Shuttle digital communication systems

NASA Technical Reports Server (NTRS)

Batson, B. H.; Seyl, J. W.; Huth, G. K.

1977-01-01

This paper describes an approach for relay of data-modulated subcarriers from Shuttle payloads through the Shuttle Ku-band communications subsystem (and subsequently through a tracking and data relay satellite system to a ground terminal). The novelty is that a channel originally provided for baseband digital data is shown to be suitable for this purpose; the resulting transmission scheme is referred to as a narrowband bent-pipe scheme. Test results demonstrating the validity of the narrowband bent-pipe mode are presented, and limitations on system performance are described.

5,10-Methylene-5,6,7,8-tetrahydrofolate conformational transitions upon binding to thymidylate synthase: molecular mechanics and continuum solvent studies

NASA Astrophysics Data System (ADS)

Jarmuła, Adam; Cieplak, Piotr; Montfort, William R.

2005-02-01

We applied the molecular mechanics Poisson-Boltzmann surface area (MM-PBSA) approach to evaluate relative stability of the extended (flat) and C-shaped (bent) solution conformational forms of the 5,10-methylene-5,6,7,8-tetrahydrofolate (mTHF) molecule in aqueous solution. Calculations indicated that both forms have similar free energies in aqueous solution but detailed energy components are different. The bent solution form has lower intramolecular electrostatic and van der Waals interaction energies. The flat form has more favorable solvation free energy and lower contribution from the bond, angle and torsion angle molecular mechanical internal energies. We exploit these results and combine them with known crystallographic data to provide a model for the progressive binding of the mTHF molecule, a natural cofactor of thymidylate synthase (TS), to the complex forming in the TS-catalyzed reaction. We propose that at the time of initial weak binding in the open enzyme the cofactor molecule remains in a close balance between the flat and bent solution conformations, with neither form clearly favored. Later, thymidylate synthase undergoes conformational change leading to the closure of the active site and the mTHF molecule is withdrawn from the solvent. That effect shifts the thermodynamic equilibrium of the mTHF molecule toward the bent solution form. At the same time, burying the cofactor molecule in the closed active site produces numerous contacts between mTHF and protein that render change in the shape of the mTHF molecule. As a result, the bent solution conformer is converted to more strained L-shaped bent enzyme conformer of the mTHF molecule. The strain in the bent enzyme conformation allows for the tight binding of the cofactor molecule to the productive ternary complex that forms in the closed active site, and facilitates the protonation of the imidazolidine N10 atom, which promotes further reaction.

High-energy x-ray optics with silicon saw-tooth refractive lenses.

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

Shastri, S. D.; Almer, J. A.; Ribbing, C. R.

2007-01-01

Silicon saw-tooth refractive lenses have been in successful use for vertical focusing and collimation of high-energy X-rays (50-100 keV) at the 1-ID undulator beamline of the Advanced Photon Source. In addition to presenting an effectively parabolic thickness profile, as required for aberration-free refractive optics, these devices allow high transmission and continuous tunability in photon energy and focal length. Furthermore, the use of a single-crystal material (i.e. Si) minimizes small-angle scattering background. The focusing performance of such saw-tooth lenses, used in conjunction with the 1-ID beamline's bent double-Laue monochromator, is presented for both short ({approx}1:0.02) and long ({approx}1:0.6) focal-length geometries, givingmore » line-foci in the 2 {micro}m-25 {micro}m width range with 81 keV X-rays. In addition, a compound focusing scheme was tested whereby the radiation intercepted by a distant short-focal-length lens is increased by having it receive a collimated beam from a nearer (upstream) lens. The collimation capabilities of Si saw-tooth lenses are also exploited to deliver enhanced throughput of a subsequently placed small-angular-acceptance high-energy-resolution post-monochromator in the 50-80 keV range. The successful use of such lenses in all these configurations establishes an important detail, that the pre-monochromator, despite being comprised of vertically reflecting bent Laue geometry crystals, can be brilliance-preserving to a very high degree.« less

25. GROUND VIEW OF PIER, LOOKING SOUTHEAST, SHOWING (LEFTRIGHT) BENTS ...

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

25. GROUND VIEW OF PIER, LOOKING SOUTHEAST, SHOWING (LEFT-RIGHT) BENTS 16-25, NEPTUNE'S LOCKER (LEFT), WITH CAPTAIN'S GALLEY BEHIND - Huntington Beach Municipal Pier, Pacific Coast Highway at Main Street, Huntington Beach, Orange County, CA

26. GROUND VIEW OF PIER, LOOKING SOUTHEAST, SHOWING (LEFTRIGHT) BENTS ...

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

26. GROUND VIEW OF PIER, LOOKING SOUTHEAST, SHOWING (LEFT-RIGHT) BENTS 18-23 NEPTUNE'S LOCKER (RIGHT), WITH CAPTAIN'S GALLEY BEHIND - Huntington Beach Municipal Pier, Pacific Coast Highway at Main Street, Huntington Beach, Orange County, CA

24. GROUND VIEW OF PIER, LOOKING SOUTHEAST, SHOWING (LEFTRIGHT) BENTS ...

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

24. GROUND VIEW OF PIER, LOOKING SOUTHEAST, SHOWING (LEFT-RIGHT) BENTS 10-19, NEPTUNE'S LOCKER (RIGHT), WITH CAPTAIN'S GALLEY BEHIND - Huntington Beach Municipal Pier, Pacific Coast Highway at Main Street, Huntington Beach, Orange County, CA

16. VIEW OF PIN CONNECTION AT U1, AND BENT TOP ...

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

16. VIEW OF PIN CONNECTION AT U1, AND BENT TOP LATERAL BAR, WEST TRUSS, SPAN 1, LOOKING WEST - Emlenton Bridge, Spanning Allegheny River, Travel Route 38 (Legislative Route 75), Emlenton, Venango County, PA

38. DETAIL VIEW OF PILINGS AT BENT 17 (CAPTAIN'S GALLEY), ...

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

38. DETAIL VIEW OF PILINGS AT BENT 17 (CAPTAIN'S GALLEY), LOOKING SOUTHWEST, SHOWING CONCRETE COLLARS AROUND GUNITE-ENCASED CONCRETE PILINGS - Huntington Beach Municipal Pier, Pacific Coast Highway at Main Street, Huntington Beach, Orange County, CA

18. DETAILED OFFSHORE VIEW OF 4TH TEE, LOOKING NORTHWEST, SHOWING ...

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

18. DETAILED OFFSHORE VIEW OF 4TH TEE, LOOKING NORTHWEST, SHOWING TRANSITION FROM WOOD BENTS TO CONCRETE BENTS - Huntington Beach Municipal Pier, Pacific Coast Highway at Main Street, Huntington Beach, Orange County, CA

Propagation of polarised light in bent hi-bi spun fibres

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

Przhiyalkovsky, Ya V; Morshnev, S K; Starostin, N I

The evolution of polarisation states (PS's) of broadband light propagating through a bent optical fibre with a helical structure of its refractive index anisotropy (hi-bi spun fibre) has been studied theoretically and experimentally. It has been shown that there exists a coordinate system of PS's in which the differential Jones matrix can be replaced by a diagonal matrix, which allows the polarisation parameters of the output broadband light to be readily calculated with sufficient accuracy. We have derived a formula for evaluating the magneto-optical sensitivity of a bent spun fibre. An approach has been proposed for restoring the degree ofmore » polarisation of light in a bent hi-bi spun fibre and, as a consequence, the visibility (contrast) of the interferometer in a current sensor with a sensing element based on the fibre under consideration. (optical fibres)« less

Deformation mechanisms of bent Si nanowires governed by the sign and magnitude of strain

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

Wang, Lihua, E-mail: wlh@bjut.edu.cn, E-mail: xdhan@bjut.edu.cn, E-mail: j.zou@uq.edu.au; Materials Engineering, The University of Queensland, Brisbane, QLD 4072; Kong, Deli

2016-04-11

In this study, the deformation mechanisms of bent Si nanowires are investigated at the atomic scale with bending strain up to 12.8%. The sign and magnitude of the applied strain are found to govern their deformation mechanisms, in which the dislocation types (full or partial dislocations) can be affected by the sign (tensile or compressive) and magnitude of the applied strain. In the early stages of bending, plastic deformation is controlled by 60° full dislocations. As the bending increases, Lomer dislocations can be frequently observed. When the strain increases to a significant level, 90° partial dislocations induced from the tensilemore » surfaces of the bent nanowires are observed. This study provides a deeper understanding of the effect of the sign and magnitude of the bending strain on the deformation mechanisms in bent Si nanowires.« less

Measurement and models of bent KAP(001) crystal integrated reflectivity and resolution (invited)

NASA Astrophysics Data System (ADS)

Loisel, G. P.; Wu, M.; Stolte, W.; Kruschwitz, C.; Lake, P.; Dunham, G. S.; Bailey, J. E.; Rochau, G. A.

2016-11-01

The Advanced Light Source beamline-9.3.1 x-rays are used to calibrate the rocking curve of bent potassium acid phthalate (KAP) crystals in the 2.3-4.5 keV photon-energy range. Crystals are bent on a cylindrically convex substrate with a radius of curvature ranging from 2 to 9 in. and also including the flat case to observe the effect of bending on the KAP spectrometric properties. As the bending radius increases, the crystal reflectivity converges to the mosaic crystal response. The X-ray Oriented Programs (xop) multi-lamellar model of bent crystals is used to model the rocking curve of these crystals and the calibration data confirm that a single model is adequate to reproduce simultaneously all measured integrated reflectivities and rocking-curve FWHM for multiple radii of curvature in both 1st and 2nd order of diffraction.

Short-wavelength InAlGaAs/AlGaAs quantum dot superluminescent diodes

NASA Astrophysics Data System (ADS)

Liang, De-Chun; An, Qi; Jin, Peng; Li, Xin-Kun; Wei, Heng; Wu, Ju; Wang, Zhan-Guo

2011-10-01

This paper reports the fabrication of J-shaped bent-waveguide superluminescent diodes utilizing an InAlGaAs/AlGaAs quantum dot active region. The emission spectrum of the device is centred at 884 nm with a full width at half maximum of 37 nm and an output power of 18 mW. By incorporating an Al composition into the quantum dot active region, short-wavelength superluminescent diode devices can be obtained. An intersection was found for the light power-injection current curves measured from the straight-waveguide facet and the bent-waveguide facet, respectively. The result is attributed to the conjunct effects of the gain and the additional loss of the bent waveguide. A numerical simulation is performed to verify the qualitative explanation. It is shown that bent waveguide loss is an important factor that affects the output power of J-shaped superluminescent diode devices.

Measurement and models of bent KAP(001) crystal integrated reflectivity and resolution (invited)

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

Loisel, G. P., E-mail: gploise@sandia.gov; Wu, M.; Lake, P.

2016-11-15

The Advanced Light Source beamline-9.3.1 x-rays are used to calibrate the rocking curve of bent potassium acid phthalate (KAP) crystals in the 2.3-4.5 keV photon-energy range. Crystals are bent on a cylindrically convex substrate with a radius of curvature ranging from 2 to 9 in. and also including the flat case to observe the effect of bending on the KAP spectrometric properties. As the bending radius increases, the crystal reflectivity converges to the mosaic crystal response. The X-ray Oriented Programs (XOP) multi-lamellar model of bent crystals is used to model the rocking curve of these crystals and the calibration datamore » confirm that a single model is adequate to reproduce simultaneously all measured integrated reflectivities and rocking-curve FWHM for multiple radii of curvature in both 1st and 2nd order of diffraction.« less

Outcomes of torsional microcoaxial phacoemulsification performed by 12-degree and 22-degree bent tips.

PubMed

Helvacioglu, Firat; Yeter, Celal; Tunc, Zeki; Sencan, Sadik

2013-08-01

To compare the safety and efficacy of Ozil Intelligent Phaco torsional microcoaxial phacoemulsification surgeries performed with 12-degree and 22-degree bent tips using the Infiniti Vision System. Maltepe University School of Medicine Department of Ophthalmology, Istanbul, Turkey. Comparative case series. Eyes were assigned to 2.2 mm microcoaxial phacoemulsification using the torsional mode with a 22-degree bent tip (Group 1) or a 12-degree bent tip (Group 2). The primary outcome measures were ultrasound time (UST), cumulative dissipated energy (CDE), longitudinal and torsional ultrasound (US) amplitudes, mean surgical time, mean volume of balanced salt solution used, and surgical complications. Both groups included 45 eyes. The mean UST, CDE, longitudinal US amplitude, and torsional US amplitude were 65 seconds ± 27.23 (SD), 11.53 ± 6.99, 0.22 ± 0.26, and 42.86 ± 15.64, respectively, in Group 1 and 84 ± 45.04 seconds, 16.68 ± 10.66, 0.48 ± 0.68, and 46.27 ± 14.74, respectively, in Group 2. The mean UST, CDE, and longitudinal amplitudes were significantly lower in Group 1 (P=.003, P=.008, and P=.022, respectively). The mean volume of balanced salt solution was 73.33 ± 28.58 cc in Group 1 and 82.08 ± 26.21 cc in Group 2 (P=.134). Torsional phacoemulsification performed with 22-degree bent tips provided more effective lens removal than 12-degree bent tips, with a lower UST and CDE. Copyright © 2013 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Flexible bent rod model with a saturating induced dipole moment to study the electric linear dichroism of DNA fragments

NASA Astrophysics Data System (ADS)

Bertolotto, Jorge A.; Umazano, Juan P.

2016-06-01

In the present work we make a theoretical study of the steady state electric linear dichroism of DNA fragments in aqueous solution. The here developed theoretical approach considers a flexible bent rod model with a saturating induced dipole moment. The electric polarizability tensor of bent DNA fragments is calculated considering a phenomenological model which theoretical and experimental backgroung is presented here. The model has into account the electric polarizability longitudinal and transversal to the macroion. Molecular flexibility is described using an elastic potential. We consider DNA fragments originally bent with bending fluctuations around an average bending angle. The induced dipole moment is supposed constant once the electric field strength grows up at critical value. To calculate the reduced electric linear dichroism we determine the optical factor considering the basis of the bent DNA perpendicular to the molecular axis. The orientational distribution function has into account the anisotropic electric properties and the molecule flexibility. We applied the present theoretical background to fit electric dichroism experimental data of DNA fragments reported in the bibliography in a wide range of molecular weight and electric field. From these fits, values of DNA physical properties are estimated. We compare and discuss the results here obtained with the theoretical and experimental data presented by other authors. The original contributions of this work are: the inclusion of the transversal electric polarizability saturating with the electric field, the description of the electric properties with an electric polarizability tensor dependant on the bending angle and the use of an arc model originally bent.

Design criteria for post and beam bents with drilled shafts.

DOT National Transportation Integrated Search

2007-12-01

The research work presented in the report addresses the potential areas of conservatism in the current practice related to bridge : bents supported by drilled shafts and piles. The research encompasses modeling efforts and an experimental program. Mo...

Development of a precast bent cap system

DOT National Transportation Integrated Search

2001-01-01

Improved speed of construction and economy can be achieved through the use of precast bridge substructures. As a step in the advancement of precast bridge substructures, a precast bent cap system is developed for nonseismic regions, including a desig...

37. DETAIL VIEW OF PILINGS AT BENT 8, LOOKING SOUTHWEST, ...

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

37. DETAIL VIEW OF PILINGS AT BENT 8, LOOKING SOUTHWEST, SHOWING PILING WITH CONCRETE COLLAR (LEFT) AND GUNITE-ENCASED PILING (RIGHT) - Huntington Beach Municipal Pier, Pacific Coast Highway at Main Street, Huntington Beach, Orange County, CA

29 CFR 1915.113 - Shackles and hooks.

Code of Federal Regulations, 2010 CFR

2010-07-01

... bends or springs the hook. (3) Hooks shall be inspected periodically to see that they have not been bent by overloading. Bent or sprung hooks shall not be used. [47 FR 16986, Apr. 20, 1982, as amended at 51...

Substructure detail view of the castinplace concrete bents and steel, ...

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

Substructure detail view of the cast-in-place concrete bents and steel, longitudinal "I" beams. - Marion Creek Bridge, Spanning Marion Creek at Milepoint 66.42 on North Santiam Highway (OR-22), Marion Forks, Linn County, OR

Precast, Prestressed Concrete Bent Caps : Volume 1, Preliminary Design Considerations and Experimental Test Program

DOT National Transportation Integrated Search

2018-04-01

Precast prestressed concrete bent caps may provide significant benefits by enabling accelerated construction of bridge substructures and improve longevity by reducing the propensity for cracking. The Texas Department of Transportation enables the use...

29 CFR 1915.113 - Shackles and hooks.

Code of Federal Regulations, 2011 CFR

2011-07-01

... bends or springs the hook. (3) Hooks shall be inspected periodically to see that they have not been bent by overloading. Bent or sprung hooks shall not be used. [47 FR 16986, Apr. 20, 1982, as amended at 51...

A novel U-bent plastic optical fibre local surface plasmon resonance sensor based on a graphene and silver nanoparticle hybrid structure

NASA Astrophysics Data System (ADS)

Jiang, Shouzhen; Li, Zhe; Zhang, Chao; Gao, Saisai; Li, Zhen; Qiu, Hengwei; Li, Chonghui; Yang, Cheng; Liu, Mei; Liu, Yanjun

2017-04-01

In this work, we have presented a novel local surface plasmon resonance (LSPR) sensor based on the U-bent plastic optical fibre (U-POF). Firstly, a layer of discontinuous silver (Ag) thin film was deposited on the U-POF and then the Ag film was covered by a layer of cladding synthesized by polyvinyl alcohol (PVA), graphene and silver nanoparticles forming the PVA/G/AgNPs@Ag film. The normalized transmittance spectrum of the LSPR sensor have been collected in a range of the refractive index (RI) from 1.330 to 1.3657 in ethanol solution, and 700.3 nm/RIU sensitivity of the developed LSPR sensor has been demonstrated. By experiments, we demonstrated that the graphene could improve the sensitivity of the LSPR sensor and delay the oxidation process of the AgNPs effectively to keep the stability of the LSPR sensor. The LSPR sensor also exhibited good sensitivity and linearity in the detection of glucose solutions. This work shows that the developed LSPR sensor may have promising applications in biosensing.

Seismic performance of an I-girder to inverted-T bent cap connection.

DOT National Transportation Integrated Search

2011-09-01

This report presents the research conducted as part of an investigation for the California Department of Transportation (Caltrans) regarding the seismic response and overall moment capacity of precast I-girder to inverted-T bent cap bridge connection...

Evaluation of bent caps in reinforced concrete deck girder bridges : part 2.

DOT National Transportation Integrated Search

2008-09-01

This report describes research conducted to enable evaluation of existing vintage bent cap beams in reinforced concrete : deck girder bridges. The report is organized into two parts: 1) flexural anchorage capacity response and prediction of : reduced...

Evaluation of bent caps in reinforced concrete deck girder bridges : part 1.

DOT National Transportation Integrated Search

2008-09-01

This report describes research conducted to enable evaluation of existing vintage bent cap beams in reinforced concrete : deck girder bridges. The report is organized into two parts: 1) flexural anchorage capacity response and prediction of : reduced...

ASR/DEF-damaged bent caps : shear tests and field implications.

DOT National Transportation Integrated Search

2009-08-01

Over the last decade, a number of reinforced concrete bent caps within Houston, Texas have exhibited premature concrete damage (cracking, spalling and a loss of material : strength) due to alkali-silica reaction (ASR) and/or delayed ettringite format...

To bend or not to bend: electronic structural analysis of linear versus bent M-H-M interactions in dinickel bis(dialkylphosphino)methane complexes.

PubMed

Wilson, Zakiya S; Stanley, George G; Vicic, David A

2010-06-21

The M-H-M bonding in the dinuclear complexes Ni(2)(mu-H)(mu-P(2))(2)X(2) (P(2) = R(2)PCH(2)PR(2), R = iPr, Cy; X = Cl, Br) has been investigated. These dinickel A-frames were studied via density functional theory (DFT) calculations to analyze the factors that influence linear and bent M-H-M bonding. The DFT calculations indicate that the bent geometry is favored electronically, with ligand steric effects driving the formation of the linear M-H-M structures.

Field alignment of bent-core smectic liquid crystals for analog optical phase modulation

NASA Astrophysics Data System (ADS)

Shen, Y.; Goodhew, L.; Shao, R.; Moran, M.; Korblova, E.; Walba, D. M.; Clark, N. A.; Maclennan, J. E.; Rudquist, P.

2015-05-01

A general method for aligning bent-core smectic liquid crystal materials is described. Alternating electric fields between interdigitated electrodes patterned on one cell surface create torques on the liquid crystal that result in uniform "bookshelf" orientation of the smectic layers. The aligned cell can then be driven in the conventional way by applying an electric field between all of the stripe electrodes connected together and a monolithic electrode on the other cell surface. Fast, analog, optical phase-only modulation is demonstrated in a device containing a polar, bent-core SmAPF material aligned using this technique.

Bent dendrite growth in undercooled Fe-B alloy melts

NASA Astrophysics Data System (ADS)

Karrasch, C.; Volkmann, T.; Valloton, J.; Kolbe, M.; Herlach, DM

2016-03-01

Dendritic growth is the main solidification mode in alloy casting. In order to control dendrite growth for materials design from the melt it is important to fully understand the influence of process conditions. This study stands as an experimental note observing bent dendrite growth in Fe-B alloys and suggesting possible explanations as induced by fluid flow, thermal, and concentrational diffusion or impurities. Electromagnetic levitation technique (EML) is used for containerless processing of undercooled melts under 1g and reduced gravity conditions in parabolic flight. Further investigations are needed to find a suitable explanation for the observed bent dendrite growth behaviour.

Data acquisition of neutron crystallography on tetragonal and triclinic forms of hen-egg-white (HEW) lysozyme with an elastically bent Si monochromator

NASA Astrophysics Data System (ADS)

Tanaka, I.; Minezaki, Y.; Harada, K.; Niimura, N.

An elastically bent silicon (EBSi) as a monochromator has been optimized for neutron diffractometers of biocrystallography. It was found that several stacked thin Si plates were easier to be bent much for the near focusing point and they increased neutron reflectivity by aligning the plates. Currently, an EBSi(1 1 1) monochromator system was equipped at a diffractometer (BIX-I). It took 50 days to collect about 12 000 reflections of hen-egg-white lysozyme. The minimum d-spacing was 2.1 Å.

Behavior of Pile to Bent Cap Connections Subjected to Seismic Forces

DOT National Transportation Integrated Search

2012-06-01

Currently the South Carolina Department of Transportation employs a detail of a plain pile embedment for the : connection between precast prestressed piles and cast-in-place bent caps. This connection has proved beneficial in terms : of time and cost...

Evaluation of bent caps in reinforced concrete deck girder bridges, part 2 : final report.

DOT National Transportation Integrated Search

2008-09-01

This report describes research conducted to enable evaluation of existing vintage bent cap beams in reinforced concrete : deck girder bridges. The report is organized into two parts: 1) flexural anchorage capacity response and prediction of : reduced...

Evaluation of bent caps in reinforced concrete deck girder bridges, part 1 : final report.

DOT National Transportation Integrated Search

2008-09-01

This report describes research conducted to enable evaluation of existing vintage bent cap beams in reinforced concrete : deck girder bridges. The report is organized into two parts: 1) flexural anchorage capacity response and prediction of : reduced...

A computer program to analyze bending of bent caps.

DOT National Transportation Integrated Search

1966-10-01

This report is one of a series of developments planned to facilitate the : use of computers in the analysis of highway bridge structures. It specifically : concerns a computer program for the bending analysis of bent caps. : The development of this p...

Effect of carbaryl on survival and development in Bombina orientalis (Boulenger) embryos.

PubMed

Kang, Han Seung; Park, Chan Jin; Gye, Myung Chan

2010-05-01

Bombina orientalis is one of the most common amphibians in the world and comprise a large proportion of their total number in Korea. B. orientalis, spawns in the farming regions at Spring when the massive application of agricultural chemicals occurs. Carbaryl, carbamate chemical is a slightly to highly toxic insecticide inhibiting acetylcholinesterase. The embryotoxicity and teratogenic effects of carbaryl on B. orientalis embryos were investigated at 5, 10, 50 and 100 muM. The survival rates of embryos at 312 h post fertilization were decreased with concentration dependent manner. Exposure to carbaryl produced 4 types of severe external abnormalities such as bent trunk, thick-set body, bent tail and ventral blister. At 5 muM carbaryl, a dose of no observed effect on embryonic survival, developmental abnormalities were significantly increased. The developmental abnormalities showed in order of frequency with bent trunk, thick-set body, bent tail and ventral blister. This result suggests that carbaryl is detrimental for embryonic survival and teratogenic by causing the axial skeletal defects in B. orientalis embryos.

The relative cost of bent-hip bent-knee walking is reduced in water.

PubMed

Kuliukas, Algis V; Milne, Nick; Fournier, Paul

2009-01-01

The debate about how early hominids walked may be characterised as two competing hypotheses: They moved with a fully upright (FU) gait, like modern humans, or with a bent-hip, bent-knee (BK) gait, like apes. Both have assumed that this bipedalism was almost exclusively on land, in trees or a combination of the two. Recent findings favoured the FU hypothesis by showing that the BK gait is 50-60% more energetically costly than a FU human gait on land. We confirm these findings but show that in water this cost differential is markedly reduced, especially in deeper water, at slower speeds and with greater knee flexion. These data suggest that the controversy about australopithecine locomotion may be eased if it is assumed that wading was a component of their locomotor repertoire and supports the idea that shallow water might have been an environment favourable to the evolution of early forms of "non-optimal" hominid bipedalism.

Spatially resolved analysis of short-range structure perturbations in a plastically bent molecular crystal

NASA Astrophysics Data System (ADS)

Panda, Manas K.; Ghosh, Soumyajit; Yasuda, Nobuhiro; Moriwaki, Taro; Mukherjee, Goutam Dev; Reddy, C. Malla; Naumov, Panče

2015-01-01

The exceptional mechanical flexibility observed with certain organic crystals defies the common perception of single crystals as brittle objects. Here, we describe the morphostructural consequences of plastic deformation in crystals of hexachlorobenzene that can be bent mechanically at multiple locations to 360° with retention of macroscopic integrity. This extraordinary plasticity proceeds by segregation of the bent section into flexible layers that slide on top of each other, thereby generating domains with slightly different lattice orientations. Microscopic, spectroscopic and diffraction analyses of the bent crystal showed that the preservation of crystal integrity when stress is applied on the (001) face requires sliding of layers by breaking and re-formation of halogen-halogen interactions. Application of stress on the (100) face, in the direction where π···π interactions dominate the packing, leads to immediate crystal disintegration. Within a broader perspective, this study highlights the yet unrecognized extraordinary malleability of molecular crystals with strongly anisotropic supramolecular interactions.

Method for characterization of a spherically bent crystal for K.alpha. X-ray imaging of laser plasmas using a focusing monochromator geometry

DOEpatents

Kugland, Nathan; Doeppner, Tilo; Glenzer, Siegfried; Constantin, Carmen; Niemann, Chris; Neumayer, Paul

2015-04-07

A method is provided for characterizing spectrometric properties (e.g., peak reflectivity, reflection curve width, and Bragg angle offset) of the K.alpha. emission line reflected narrowly off angle of the direct reflection of a bent crystal and in particular of a spherically bent quartz 200 crystal by analyzing the off-angle x-ray emission from a stronger emission line reflected at angles far from normal incidence. The bent quartz crystal can therefore accurately image argon K.alpha. x-rays at near-normal incidence (Bragg angle of approximately 81 degrees). The method is useful for in-situ calibration of instruments employing the crystal as a grating by first operating the crystal as a high throughput focusing monochromator on the Rowland circle at angles far from normal incidence (Bragg angle approximately 68 degrees) to make a reflection curve with the He-like x-rays such as the He-.alpha. emission line observed from a laser-excited plasma.

Wire in the Cable-Driven System of Surgical Robot

NASA Astrophysics Data System (ADS)

Wang, X. F.; Lv, N.; Mu, H. Z.; Xue, L. J.

2017-07-01

During the evolution of the surgical robot, cable plays an important role. It translates motion and force precisely from surgeon’s hand to the tool’s tips. In the paper, the vertical wires, the composition of cable, are mathematically modeled from a geometric point of view. The cable structure and tension are analyzed according to the characteristics of wire screw twist. The structural equations of the wires in different positions are derived for both non-bent cable and bent cable, respectively. The bending moment formula of bent cable is also obtained. This will help researchers find suitable cable and design more matched pulley.

Shear repair methods for conventionally reinforced concrete girders and bent caps.

DOT National Transportation Integrated Search

2009-12-01

Thirteen large-scale girders and two bent caps that replicated as close as possible bridge components from the 1950s were cast and loaded to cause initial cracking similar to that observed in the field. The girders were repaired with epoxy crack inje...

Shear repair methods for conventionally reinforced concrete girders and bent caps : appendices.

DOT National Transportation Integrated Search

2009-12-01

Thirteen large-scale girders and two bent caps that replicated as close as possible bridge components from the 1950s were cast and loaded to cause initial cracking similar to that observed in the field. The girders were repaired with epoxy crack inje...

A precast concrete bridge bent designed to re-center after an earthquake : draft research report, August 2008.

DOT National Transportation Integrated Search

2008-08-01

In this study the post-earthquake residual displacements of reinforced concrete bridge bents were investigated. The system had mild steel that was intended to dissipate energy and an unbonded, post-tensioned tendon that was supposed to remain elastic...

A precast concrete bridge bent designed to re-center after an earthquake : research report, October 2008.

DOT National Transportation Integrated Search

2008-10-01

In this study the post-earthquake residual displacements of reinforced concrete bridge bents were investigated. The system had mild steel that was intended to dissipate energy and an unbonded, post-tensioned tendon that was supposed to remain elastic...

CAD and CAE Analysis for Siphon Jet Toilet

NASA Astrophysics Data System (ADS)

Wang, Yuhua; Xiu, Guoji; Tan, Haishu

The high precision 3D laser scanner with the dual CCD technology was used to measure the original design sample of a siphon jet toilet. The digital toilet model was constructed from the cloud data measured with the curve and surface fitting technology and the CAD/CAE systems. The Realizable k - ɛ double equation model of the turbulence viscosity coefficient method and the VOF multiphase flow model were used to simulate the flushing flow in the toilet digital model. Through simulating and analyzing the distribution of the flushing flow's total pressure, the flow speed at the toilet-basin surface and the siphoning bent tube, the toilet performance can be evaluated efficiently and conveniently. The method of "establishing digital model, flushing flow simulating, performances evaluating, function shape modifying" would provide a high efficiency approach to develop new water-saving toilets.

Repair of Morganza Spillway Bridge bent pile cap using carbon fiber reinforcement (CFR).

DOT National Transportation Integrated Search

2016-04-01

The pile cap of an end bent of the Morganza Spillway Bridge suffered extensive damage at the girder bearing locations, : particularly on the side where the pounding of the girders by the adjacent concrete deck located on the approach side of the : be...

Bent Creek demonstration program

Treesearch

Erik C. Berg

1997-01-01

Bent Creek Research and Demonstration Forest scientists have transferred the results of research on the ecology and management of Southern Appalachian hardwoods since 1925. Since 1989, a full-time technology transfer specialist has led demonstration efforts. The demonstration program was designed to quickly transfer research results to interested users and to free...

Breeding biology and behavior of Hammond's and western flycatchers in northwestern California

Treesearch

H.F. Sakai

1988-01-01

The Hammond's (Empidonax hammondii) and Western (E. difficilis) flycatchers are sympatric within portions of their breeding ranges in north- western California. Westerns are common in a variety of habitats (Bent 1942:247, Johnson 1980:11-23); Hammond's are more abundant at higher elevations (Bent 1942:226, Johnson...

10. DETAILS OF STEEL FLUME, TYPICAL BENTS AND TRUSSES. EXHIBIT ...

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

10. DETAILS OF STEEL FLUME, TYPICAL BENTS AND TRUSSES. EXHIBIT L, SANTA ANA RIVER NO. 1 PROJECT, APR. 30, 1945. SCE drawing no. 523196 (sheet no. 6; for filing with Federal Power Commission). - Santa Ana River Hydroelectric System, Flumes & Tunnels below Sandbox, Redlands, San Bernardino County, CA

36. VIEW OF FRAMING BENT BETWEEN SECONDARY THICKENER No. 3 ...

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

36. VIEW OF FRAMING BENT BETWEEN SECONDARY THICKENER No. 3 AND PRIMARY THICKENER No. 2 FROM WEST. NOTE MECHANISM ON PRIMARY No. 2 ON LEFT, BARREN SOLUTION FEED PIPE AT LOWER RIGHT. - Bald Mountain Gold Mill, Nevada Gulch at head of False Bottom Creek, Lead, Lawrence County, SD

Shear repair methods for conventionally reinforced concrete girders and bent caps : final report, December 2009.

DOT National Transportation Integrated Search

2009-12-01

Thirteen large-scale girders and two bent caps that replicated as close as possible bridge components from the 1950s were cast and loaded to cause initial cracking similar to that observed in the field. The girders were repaired with epoxy crack inje...

Bent Creek demonstration program

Treesearch

Erik C. Berg

1997-01-01

Bent Creek Research and Demonstration Forest scientists have transferred the results of research on the ecology and management of Southern Appalachian hardwoods since 1925. Since 1989, a full-time technology transfer specialist has led demonstration efforts. The demonstration program was designed to quickly transfer research results to interested users, and free-up...

Determination of helix orientations in a flexible DNA by multi-frequency EPR spectroscopy.

PubMed

Grytz, C M; Kazemi, S; Marko, A; Cekan, P; Güntert, P; Sigurdsson, S Th; Prisner, T F

2017-11-15

Distance measurements are performed between a pair of spin labels attached to nucleic acids using Pulsed Electron-Electron Double Resonance (PELDOR, also called DEER) spectroscopy which is a complementary tool to other structure determination methods in structural biology. The rigid spin label Ç, when incorporated pairwise into two helical parts of a nucleic acid molecule, allows the determination of both the mutual orientation and the distance between those labels, since Ç moves rigidly with the helix to which it is attached. We have developed a two-step protocol to investigate the conformational flexibility of flexible nucleic acid molecules by multi-frequency PELDOR. In the first step, a library with a broad collection of conformers, which are in agreement with topological constraints, NMR restraints and distances derived from PELDOR, was created. In the second step, a weighted structural ensemble of these conformers was chosen, such that it fits the multi-frequency PELDOR time traces of all doubly Ç-labelled samples simultaneously. This ensemble reflects the global structure and the conformational flexibility of the two-way DNA junction. We demonstrate this approach on a flexible bent DNA molecule, consisting of two short helical parts with a five adenine bulge at the center. The kink and twist motions between both helical parts were quantitatively determined and showed high flexibility, in agreement with a Förster Resonance Energy Transfer (FRET) study on a similar bent DNA motif. The approach presented here should be useful to describe the relative orientation of helical motifs and the conformational flexibility of nucleic acid structures, both alone and in complexes with proteins and other molecules.

Bent-tailed radio sources in the australia telescope large area survey of the Chandra deep field south

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

Dehghan, S.; Johnston-Hollitt, M.; Franzen, T. M. O.

2014-11-01

Using the 1.4 GHz Australia Telescope Large Area Survey, supplemented by the 1.4 GHz Very Large Array images, we undertook a search for bent-tailed (BT) radio galaxies in the Chandra Deep Field South. Here we present a catalog of 56 detections, which include 45 BT sources, 4 diffuse low-surface-brightness objects (1 relic, 2 halos, and 1 unclassified object), and a further 7 complex, multi-component sources. We report BT sources with rest-frame powers in the range 10{sup 22} ≤ P {sub 1.4} {sub GHz} ≤ 10{sup 26} W Hz{sup –1}, with redshifts up to 2 and linear extents from tens ofmore » kiloparsecs up to about 1 Mpc. This is the first systematic study of such sources down to such low powers and high redshifts and demonstrates the complementary nature of searches in deep, limited area surveys as compared to shallower, large surveys. Of the sources presented here, one is the most distant BT source yet detected at a redshift of 2.1688. Two of the sources are found to be associated with known clusters: a wide-angle tail source in A3141 and a putative radio relic which appears at the infall region between the galaxy group MZ 00108 and the galaxy cluster AMPCC 40. Further observations are required to confirm the relic detection, which, if successful, would demonstrate this to be the least powerful relic yet seen with P {sub 1.4} {sub GHz} = 9 × 10{sup 22} W Hz{sup –1}. Using these data, we predict future 1.4 GHz all-sky surveys with a resolution of ∼10 arcsec and a sensitivity of 10 μJy will detect of the order of 560,000 extended low-surface-brightness radio sources of which 440,000 will have a BT morphology.« less

31 CFR 100.11 - Exchange of bent and partial coins.

Code of Federal Regulations, 2013 CFR

2013-07-01

... partial coins shall be presented separately by denomination category in lots of at least one pound for... redeemed at the face value equivalent of copper one cent coins. (c) Redemption site. Bent and partial coins will be redeemed only at the United States Mint, P.O. Box 400, Philadelphia, PA 19105. Coins are...

Develop Strong and Serviceable Details for Precast, Prestressed Concrete Bent Cap Standards That Can Be Implemented on Everyday Bridge Construction Projects, Project Summary

DOT National Transportation Integrated Search

2018-01-01

Pretensioned bent caps are an attractive substructure component because they offer contractors an option for fabrication by prestressing plants and can be used to eliminate or reduce cracks. Two sets of design recommendations were developed to enable...

Repair of Morganza Spillway Bridge Bent Pile Cap Using Carbon Fiber Reinforcement (CFR) : Research Project Capsule

DOT National Transportation Integrated Search

2012-09-01

The pile cap of an end bent of the Morganza Spillway Bridge suff ered extensive damage at the girder bearing : locations on one side, due to the pounding of the girders at these locations by the adjacent concrete deck : located on the approach side o...

Role of bentonite clays on cell growth.

PubMed

Cervini-Silva, Javiera; Ramírez-Apan, María Teresa; Kaufhold, Stephan; Ufer, Kristian; Palacios, Eduardo; Montoya, Ascención

2016-04-01

Bentonites, naturally occurring clays, are produced industrially because of their adsorbent capacity but little is known about their effects on human health. This manuscript reports on the effect of bentonites on cell growth behaviour. Bentonites collected from India (Bent-India), Hungary (Bent-Hungary), Argentina (Bent-Argentina), and Indonesia (Bent-Indonesia) were studied. All four bentonites were screened in-vitro against two human cancer cell lines [U251 (central nervous system, glioblastoma) and SKLU-1 (lung adenocarcinoma)] supplied by the National Cancer Institute (USA). Bentonites induced growth inhibition in the presence of U251 cells, and growth increment in the presence of SKLU-1 cells, showing that interactions between bentonite and cell surfaces were highly specific. The proliferation response for U251 cells was explained because clay surfaces controlled the levels of metabolic growth components, thereby inhibiting the development of high-grade gliomas, particularly primary glioblastomas. On the other hand, the proliferation response for SKLU-1 was explained by an exacerbated growth favoured by swelling, and concomitant accumulation of solutes, and their hydration and transformation via clay-surface mediated reactions. Copyright © 2016 Elsevier Ltd. All rights reserved.

Investigation of the effect of a bend in a transfer line that separates a pulse tube cold head and a pressure wave generator

NASA Astrophysics Data System (ADS)

Dev, A. A.; Atrey, M. D.; Vanapalli, S.

2017-02-01

A transfer line between a pulse tube cold head and a pressure wave generator is usually required to isolate the cold head from the vibrations of the compressor. Although it is a common practice to use a thin and narrow straight tube, a bent tube would allow design flexibility and easy mounting of the cold head, such as in a split Stirling type pulse tube cryocooler. In this paper, we report a preliminary investigation on the effect of the bending of the tube on the flow transfer characteristics. A numerical study using commercial computational fluid dynamics model is performed to gain insight into the flow characteristics in the bent tube. Oscillating flow experiments are performed with a straight and a bent tube at a filling pressure of 15 bar and an operating frequency of 40, 50 and 60 Hz. The data and the corresponding numerical simulations point to the hypothesis that the secondary flow in the bent tube causes a decrease in flow at a fixed pressure amplitude.

The change of the inlet geometry of a centrifugal compressor stage and its influence on the compressor performance

NASA Astrophysics Data System (ADS)

Wang, Leilei; Yang, Ce; Zhao, Ben; Lao, Dazhong; Ma, Chaochen; Li, Du

2013-06-01

The impact on the compressor performance is important for designing the inlet pipe of the centrifugal compressor of a vehicle turbocharger with different inlet pipes. First, an experiment was performed to determine the compressor performance from three cases: a straight inlet pipe, a long bent inlet pipe and a short bent inlet pipe. Next, dynamic sensors were installed in key positions to collect the sign of the unsteady pressure of the centrifugal compressor. Combined with the results of numerical simulations, the total pressure distortion in the pipes, the pressure distributions on the blades and the pressure variability in the diffuser are studied in detail. The results can be summarized as follows: a bent pipe results in an inlet distortion to the compressor, which leads to performance degradation, and the effect is more apparent as the mass flow rate increases. The distortion induced by the bent inlet is not only influenced by the distance between the outlet of the bent section and the leading edge of the impeller but also by the impeller rotation. The flow fields in the centrifugal impeller and the diffuser are influenced by a coupling effect produced by the upstream inlet distortion and the downstream blocking effect from the volute tongue. If the inlet geometry is changed, the distributions and the fluctuation intensities of the static pressure on the main blade surface of the centrifugal impeller and in the diffuser are changed accordingly.

Interactions between posture and locomotion: motor patterns in humans walking with bent posture versus erect posture.

PubMed

Grasso, R; Zago, M; Lacquaniti, F

2000-01-01

Human erect locomotion is unique among living primates. Evolution selected specific biomechanical features that make human locomotion mechanically efficient. These features are matched by the motor patterns generated in the CNS. What happens when humans walk with bent postures? Are normal motor patterns of erect locomotion maintained or completely reorganized? Five healthy volunteers walked straight and forward at different speeds in three different postures (regular, knee-flexed, and knee- and trunk-flexed) while their motion, ground reaction forces, and electromyographic (EMG) activity were recorded. The three postures imply large differences in the position of the center of body mass relative to the body segments. The elevation angles of the trunk, pelvis, and lower limb segments relative to the vertical in the sagittal plane, the ground reaction forces and the rectified EMGs were analyzed over the gait cycle. The waveforms of the elevation angles along the gait cycle remained essentially unchanged irrespective of the adopted postures. The first two harmonics of these kinematic waveforms explain >95% of their variance. The phase shift but not the amplitude ratio between the first harmonic of the elevation angle waveforms of adjacent pairs was affected systematically by changes in posture. Thigh, shank, and foot angles covaried close to a plane in all conditions, but the plane orientation was systematically different in bent versus erect locomotion. This was explained by the changes in the temporal coupling among the three segments. For walking speeds >1 m s(-1), the plane orientation of bent locomotion indicates a much lower mechanical efficiency relative to erect locomotion. Ground reaction forces differed prominently in bent versus erect posture displaying characteristics intermediate between those typical of walking and those of running. Mean EMG activity was greater in bent postures for all recorded muscles independent of the functional role. The waveforms of the muscle activities and muscle synergies also were affected by the adopted posture. We conclude that maintaining bent postures does not interfere either with the generation of segmental kinematic waveforms or with the planar constraint of intersegmental covariation. These characteristics are maintained at the expense of adjustments in kinetic parameters, muscle synergies and the temporal coupling among the oscillating body segments. We argue that an integrated control of gait and posture is made possible because these two motor functions share some common principles of spatial organization.

Binding to the minor groove of the double-strand, tau protein prevents DNA from damage by peroxidation.

PubMed

Wei, Yan; Qu, Mei-Hua; Wang, Xing-Sheng; Chen, Lan; Wang, Dong-Liang; Liu, Ying; Hua, Qian; He, Rong-Qiao

2008-07-02

Tau, an important microtubule associated protein, has been found to bind to DNA, and to be localized in the nuclei of both neurons and some non-neuronal cells. Here, using electrophoretic mobility shifting assay (EMSA) in the presence of DNA with different chain-lengths, we observed that tau protein favored binding to a 13 bp or a longer polynucleotide. The results from atomic force microscopy also showed that tau protein preferred a 13 bp polynucleotide to a 12 bp or shorter polynucleotide. In a competitive assay, a minor groove binder distamycin A was able to replace the bound tau from the DNA double helix, indicating that tau protein binds to the minor groove. Tau protein was able to protect the double-strand from digestion in the presence of DNase I that was bound to the minor groove. On the other hand, a major groove binder methyl green as a negative competitor exhibited little effect on the retardation of tau-DNA complex in EMSA. This further indicates the DNA minor groove as the binding site for tau protein. EMSA with truncated tau proteins showed that both the proline-rich domain (PRD) and the microtubule-binding domain (MTBD) contributed to the interaction with DNA; that is to say, both PRD and MTBD bound to the minor groove of DNA and bent the double-strand, as observed by electron microscopy. To investigate whether tau protein is able to prevent DNA from the impairment by hydroxyl free radical, the chemiluminescence emitted by the phen-Cu/H(2)O(2)/ascorbate was measured. The emission intensity of the luminescence was markedly decreased when tau protein was present, suggesting a significant protection of DNA from the damage in the presence of hydroxyl free radical.

The "Global" Formulation of Thermodynamics and the First Law: 50 Years On

ERIC Educational Resources Information Center

Gislason, Eric A.; Craig, Norman C.

2011-01-01

Nearly 50 years ago, Henry Bent published his groundbreaking article in this "Journal" introducing the "global" formulation of thermodynamics. In the following years, the global formulation was elaborated by Bent and by one of the present authors. The global formulation of the first law focuses on conservation of energy and the recognition that…

Evaluation of a timber column bent substructure after more than 60 years in-service

Treesearch

James P. Wacker; Xiping Wang; Douglas R. Rammer; William J. Nelson

2011-01-01

This paper describes both the field evaluation and laboratory testing of two timber-column-bent bridge substructures. These substructures served as intermediate pier supports for the East Deer Park Drive Bridge located in Gaithersburg, Maryland. A field evaluation of the bridge substructure was conducted in September 2008. Nondestructive testing was performed with a...

Effect of stress on amorphous bent cores

NASA Astrophysics Data System (ADS)

Saito, Akihiko; Yamamoto, Ken-ichi; Kunimori, Osamu

1992-07-01

The effect of stress on bent amorphous cores with positive magnetostriction has been investigated. Tension has been applied to the ribbon while winding into the toroid to improve the magnetic properties of the core. The properties of the coercive force of the tension winding core due to applied tension have been made clear from the observation of the domain structure.

A feasibility study of high-strength Bi-2223 conductor for high-field solenoids

NASA Astrophysics Data System (ADS)

Godeke, A.; Abraimov, D. V.; Arroyo, E.; Barret, N.; Bird, M. D.; Francis, A.; Jaroszynski, J.; Kurteva, D. V.; Markiewicz, W. D.; Marks, E. L.; Marshall, W. S.; McRae, D. M.; Noyes, P. D.; Pereira, R. C. P.; Viouchkov, Y. L.; Walsh, R. P.; White, J. M.

2017-03-01

We performed a feasibility study on a high-strength Bi{}2-xPb x Sr2Ca2Cu3O{}10-x(Bi-2223) tape conductor for high-field solenoid applications. The investigated conductor, DI-BSCCO Type HT-XX, is a pre-production version of Type HT-NX, which has recently become available from Sumitomo Electric Industries. It is based on their DI-BSCCO Type H tape, but laminated with a high-strength Ni-alloy. We used stress-strain characterizations, single- and double-bend tests, easy- and hard-way bent coil-turns at various radii, straight and helical samples in up to 31.2 T background field, and small 20-turn coils in up to 17 T background field to systematically determine the electro-mechanical limits in magnet-relevant conditions. In longitudinal tensile tests at 77 K, we found critical stress- and strain-levels of 516 MPa and 0.57%, respectively. In three decidedly different experiments we detected an amplification of the allowable strain with a combination of pure bending and Lorentz loading to ≥slant 0.92 % (calculated elastically at the outer tape edge). This significant strain level, and the fact that it is multi-filamentary conductor and available in the reacted and insulated state, makes DI-BSCCO HT-NX highly suitable for very high-field solenoids, for which high current densities and therefore high loads are required to retain manageable magnet dimensions.

A Feasibility Study of High-Strength Bi-2223 Conductor for High-Field Solenoids

PubMed Central

Godeke, A; Abraimov, D V; Arroyo, E; Barret, N; Bird, M D; Francis, A; Jaroszynski, J; Kurteva, D V; Markiewicz, W D; Marks, E L; Marshall, W S; McRae, D M; Noyes, P D; Pereira, R C P; Viouchkov, Y L; Walsh, R P; White, J M

2017-01-01

We performed a feasibility study on a high-strength Bi2−xPbxSr2Ca2Cu3O10−x (Bi-2223) tape conductor for high-field solenoid applications. The investigated conductor, DI-BSCCO Type HT-XX, is a pre-production version of Type HT-NX, which has recently become available from Sumitomo Electric Industries (SEI). It is based on their DI-BSCCO Type H tape, but laminated with a high-strength Ni-alloy. We used stress-strain characterizations, single- and double-bend tests, easy- and hard-way bent coil-turns at various radii, straight and helical samples in up to 31.2 T background field, and small 20-turn coils in up to 17 T background field to systematically determine the electro-mechanical limits in magnet-relevant conditions. In longitudinal tensile tests at 77 K, we found critical stress- and strain-levels of 516 MPa and 0.57%, respectively. In three decidedly different experiments we detected an amplification of the allowable strain with a combination of pure bending and Lorentz loading to ≥ 0.92% (calculated elastically at the outer tape edge). This significant strain level, and the fact that it is multi-filamentary conductor and available in the reacted and insulated state, makes DI-BSCCO HT-NX highly suitable for very high-field solenoids, for which high current densities and therefore high loads are required to retain manageable magnet dimensions. PMID:28360455

Flexible metasurface black nickel with stepped nanopillars.

PubMed

Qian, Qinyu; Yan, Ying; Wang, Chinhua

2018-03-15

We report on a monolithic, all-metallic, and flexible metasurface perfect absorber [black nickel (Ni)] based on coupled Mie resonances originated from vertically stepped Ni nanopillars homoepitaxially grown on an Ni substrate. Coupled Mie resonances are generated from Ni nanopillars with different sizes such that Mie resonances of the stepped two sets of Ni nanopillars occur complementarily at different wavelengths to realize polarization-independent broadband absorption over the entire visible wavelength band (400-760 nm) within an ultra-thin surface layer of only 162 nm thick in total. Two-step double-beam interference lithography and electroplating are utilized to fabricate the proposed monolithic metasurface that can be arbitrarily bent and pressed. A black nickel metasurface is experimentally demonstrated in which an average polarization-independent absorption of 0.972 (0.961, experiment) in the entire visible band is achieved and remains 0.838 (0.815, experiment) when the incident angle increases to 70°.

Comparative assessment of laparoscopic single-site surgery instruments to conventional laparoscopic in laboratory setting.

PubMed

Stolzenburg, Jens-Uwe; Kallidonis, Panagiotis; Oh, Min-A; Ghulam, Nabi; Do, Minh; Haefner, Tim; Dietel, Anja; Till, Holger; Sakellaropoulos, George; Liatsikos, Evangelos N

2010-02-01

Laparoendoscopic single-site surgery (LESS) represents the latest innovation in laparoscopic surgery. We compare in dry and animal laboratory the efficacy of recently introduced pre-bent instruments with conventional laparoscopic and flexible instruments in terms of time requirement, maneuverability, and ease of handling. Participants of varying laparoscopic experience were included in the study and divided in groups according to their experience. The participants performed predetermined tasks in dry laboratory using all sets of instruments. An experienced laparoscopic surgeon performed 24 nephrectomies in 12 pigs using all sets of instruments. Single port was used for all instrument sets except for the conventional instruments, which were inserted through three ports. The time required for the performance of dry laboratory tasks and the porcine nephrectomies was recorded. Errors in the performance of dry laboratory tasks of each instrument type were also recorded. Pre-bent instruments had a significant advantage over flexible instruments in terms of time requirement to accomplish tasks and procedures as well as maneuverability. Flexible instruments were more time consuming in comparison to the conventional laparoscopic instruments during the performance of the tasks. There were no significant differences in the time required for the accomplishment of dry laboratory tasks or steps of nephrectomy using conventional instruments through appropriate number of ports in comparison to pre-bent instruments through single port. Pre-bent instruments were less time consuming and with better maneuverability in comparison to flexible instruments in experimental single-port access surgery. Further clinical investigations would elucidate the efficacy of pre-bent instruments.

31. Photographic copy of Leanto Roof Framing Plan & Bent ...

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

31. Photographic copy of Leanto Roof Framing Plan & Bent Details (Ammann and Whitney and The Balinger Company, April 12, 1955). In files of the City of Philadelphia, Division of Aviation, Terminal E, Philadelphia International Airport. Reprinted with permission of the Division of Aviation. - TWA Maintenance Hangar, South side of Tinicum Island Road, Philadelphia International Airport, Philadelphia, Philadelphia County, PA

The Invisible Blockade and the Covert War: U.S. Relations with Chile, 1970-1973

DTIC Science & Technology

1979-06-01

U.S.- owned multinational corporations , pursued a course of action, publicly, economically and covertly, bent on discrediting, disrupting and dislodging...government, in concert with U.S.- .owned multinational corporations , pursued a course of action, publicly, economically and covertly, bent on...513 E. CONCLUSION -------------------------------------- 64 IV. COVERT GOVERNMENTAL AND CORPORATE PRESSURES-------- 67 A. ATTEMPTS TO KEEP

Evolution of turbulence characteristics from straight to curved pipes

NASA Astrophysics Data System (ADS)

El Khoury, George K.; Noorani, Azad; Schlatter, Philipp; Fischer, Paul F.

2012-11-01

Large-scale direct numerical simulations are performed to study turbulent flow in straight and bent pipes at four different Reynolds numbers: Reb = 5300 , 11700 (bent and straight) and 19000 and 37700 (only straight). We consider a pipe of radius R and axial length 25 R with curvature parameter κ taken to be 0 , 0 . 01 and 0 . 1 for zero, mild and strong curvatures, respectively. The code used is Nek5000 based on the spectral element method. In the straight configuration, the obtained DNS data is carefully checked against other recent simulations, highlighting minute differences between the available data. Owing to a centrifugal instability mechanism, the flow in bent pipe (κ ≠ 0) develops counter-rotating vortices, so-called Dean vortices. The presence of the secondary motion thus induces substantial asymmetries both in the mean flow and turbulence characteristics for the bent pipe. These asymmetries tend to damp turbulence along the inner side and correspondingly enhance it along the upper side. The results are validated with recent experiments, and we could confirm the peculiar behaviour of the friction factor for specific curvatures and Re , leading to a lower friction in curved pipes than in straight pipes for the same mass flux.

Bent channel design in buried Er3+/Yb3+ codoped phosphate glass waveguide fabricated by field-assisted annealing

NASA Astrophysics Data System (ADS)

Zhao, Ruitu; Wang, Mu; Chen, Baojie; Liu, Ke; Pun, Edwin Yue-Bun; Lin, Hai

2011-04-01

Bent waveguide structures (S-, U-, and F-bend) based on buried Er3+/Yb3+ codoped phosphate glass waveguide channel fabricated by field-assisted annealing have been designed to achieve high-gain C-band integrated amplification. Using a simulated-bend method, the optimal radius for the curved structure is derived to be 0.90 cm with loss coefficient of 0.02 dB/cm, as the substrate size is schemed to be 4×3 cm2. In the wavelength range of 1520 to 1575 nm, obvious gain enhancement for the bent structure waveguides is anticipated, and for the F-bend waveguide, the internal gain at 1534-nm wavelength is derived to be 41.61 dB, which is much higher than the value of 26.22 and 13.81 dB in the U- and S-bend waveguides, respectively, and over three times higher than that of the straight one. The simulation results indicate that the bent structure design is beneficial in obtaining high signal gain in buried Er3+/Yb3+ codoped phosphate glass waveguides, which lays the foundation for further design and fabrication of integrated devices.

Stabilization of heavy metals in soil using two organo-bentonites.

PubMed

Yu, Kai; Xu, Jian; Jiang, Xiaohong; Liu, Cun; McCall, Wesley; Lu, Jinlong

2017-10-01

Stabilization of Cu, Zn, Cd, Hg, Cr and As in soil using tetramethylammonium (TMA) and dodecyltrimethylammonium (DTMA) modified bentonites (T-Bents and D-Bents) as amendments was investigated. Toxicity characteristic leaching procedure (TCLP) was used to quantify the metal mobility after soil treatment. The structural parameters of modified bentonites, including the BET surface area, basal spacing and zeta potential were obtained as a function of the TMA and DTMA loading at 40, 80, 120, 160 and 200% of the bentonite's cation exchange capacity, respectively. The results indicated that the characteristics of the organo-bentonites fundamentally varied depending on the species and concentration of modifiers loaded on bentonite. T-Bents and D-Bents manifested distinct immobilization effectiveness towards various metals. In association with the organo-bentonite characteristics, the main interactive mechanisms for Cu, Zn and Cd proceeded via cation exchange, Hg proceeded via physical adsorption and partitioning, Cr and As proceeded via specific adsorption and electrostatic attraction, respectively. This study provided operational and mechanistic basis for optimizing the organic clay synthesis and selecting as the appropriate amendment for remediation of heavy metal contaminated soils. Copyright © 2017 Elsevier Ltd. All rights reserved.

Direct synchrotron x-ray measurements of local strain fields in elastically and plastically bent metallic glasses

DOE PAGES

Wu, Yuan; Stoica, Alexandru Dan; Ren, Yang; ...

2015-09-03

In situ high-energy synchrotron X-ray diffraction was conducted on elastically and plastically bent bulk metallic glass (BMG) thin plates, from which distinct local elastic strain fields were mapped spatially. These directly measured residual strain fields can be nicely interpreted by our stress analysis, and also validate a previously proposed indirect residual-stress-measurement method by relating nanoindentation hardness to residual stresses. Local shear strain variations on the cross sections of these thin plates were found in the plastically bent BMG, which however cannot be determined from the indirect indentation method. As a result, this study has important implications in designing and manipulatingmore » internal strain fields in BMGs for the purpose of ductility enhancement.« less

Optical properties of amorphous Ba0.7Sr0.3TiO3 thin films obtained by metal organic decomposition technique

NASA Astrophysics Data System (ADS)

Qiu, Fei; Xu, Zhimou

2009-08-01

In this study, the amorphous Ba0.7Sr0.3TiO3 (BST0.7) thin films were grown onto fused quartz and silicon substrates at low temperature by using a metal organic decomposition (MOD)-spin-coating procedure. The optical transmittance spectrum of amorphous BST0.7 thin films on fused quartz substrates has been recorded in the wavelength range 190~900 nm. The films were highly transparent for wavelengths longer than 330 nm; the transmission drops rapidly at 330 nm, and the cutoff wavelength occurs at about 260 nm. In addition, we also report the amorphous BST0.7 thin film groove-buried type waveguides with 90° bent structure fabricated on Si substrates with 1.65 μm thick SiO2 thermal oxide layer. The design, fabrication and optical losses of amorphous BST0.7 optical waveguides were presented. The amorphous BST0.7 thin films were grown onto the SiO2/Si substrates by using a metal organic decomposition (MOD)-spin-coating procedure. The optical propagation losses were about 12.8 and 9.4 dB/cm respectively for the 5 and 10 μm wide waveguides at the wavelength of 632.8 nm. The 90° bent structures with a small curvature of micrometers were designed on the basis of a double corner mirror structure. The bend losses were about 1.2 and 0.9 dB respectively for 5 and 10 μm wide waveguides at the wavelength of 632.8 nm. It is expected for amorphous BST0.7 thin films to be used not only in the passive optical interconnection in monolithic OEICs but also in active waveguide devices on the Si chip.

Earth Observations taken by the Expedition 17 Crew

NASA Image and Video Library

2008-05-30

ISS017-E-008285 (30 May 2008) --- Pyramids of Dashur, Egypt are featured in this image photographed by an Expedition 17 crewmember on the International Space Station. While the pyramids of Giza are perhaps the most famous, there are several other ancient Egyptian royal necropolis ("city of the dead") sites situated along the Nile River and its delta. One of these sites is located near the village of Dashur (upper right). The gray-brown built area of Dashur is surrounded by green agricultural land of the Nile Delta, which forms a distinct boundary with the tan desert to the west. It is in the desert that the monuments of the ancient rulers of Egypt are found. Several monuments are visible in this image, including the large Red and Bent Pyramids built by Snofru, first king of the 4th Dynasty that lasted from 2575-2465 BC. Other visible monuments include the pyramid complexes of Amenemhat III and Sesostris III, both kings of the 12th Dynasty (1991-1783 BC). Both of these complexes are poorly preserved, due both to unstable ground conditions, and dismantling of the limestone blocks forming the outer pyramid casings during later historical periods. The Bent Pyramid (lower right) is so called as the slope of the outer face was lessened halfway through construction, leading to a distinctive "bent" profile -- explanations for why this was done include decreasing the mass of the pyramid to prevent collapse, or to reduce the work necessary to complete it. The Red Pyramid to the north (center) was built after the Bent Pyramid, and is named for the coloration of the building stone at the structure's core. An irregular dark feature to the southeast of the Bent Pyramid is not a shadow cast by a monument; it is an irrigation feature extending into the desert.

Thermoacoustic imaging of fresh prostates up to 6-cm diameter

NASA Astrophysics Data System (ADS)

Patch, S. K.; Hanson, E.; Thomas, M.; Kelly, H.; Jacobsohn, K.; See, W. A.

2013-03-01

Thermoacoustic (TA) imaging provides a novel contrast mechanism that may enable visualization of cancerous lesions which are not robustly detected by current imaging modalities. Prostate cancer (PCa) is the most notorious example. Imaging entire prostate glands requires 6 cm depth penetration. We therefore excite TA signal using submicrosecond VHF pulses (100 MHz). We will present reconstructions of fresh prostates imaged in a well-controlled benchtop TA imaging system. Chilled glycine solution is used as acoustic couplant. The urethra is routinely visualized as signal dropout; surgical staples formed from 100-micron wide wire bent to 3 mm length generate strong positive signal.

The Language of Glove: Wireless gesture decoder with low-power and stretchable hybrid electronics.

PubMed

O'Connor, Timothy F; Fach, Matthew E; Miller, Rachel; Root, Samuel E; Mercier, Patrick P; Lipomi, Darren J

2017-01-01

This communication describes a glove capable of wirelessly translating the American Sign Language (ASL) alphabet into text displayable on a computer or smartphone. The key components of the device are strain sensors comprising a piezoresistive composite of carbon particles embedded in a fluoroelastomer. These sensors are integrated with a wearable electronic module consisting of digitizers, a microcontroller, and a Bluetooth radio. Finite-element analysis predicts a peak strain on the sensors of 5% when the knuckles are fully bent. Fatigue studies suggest that the sensors successfully detect the articulation of the knuckles even when bent to their maximal degree 1,000 times. In concert with an accelerometer and pressure sensors, the glove is able to translate all 26 letters of the ASL alphabet. Lastly, data taken from the glove are used to control a virtual hand; this application suggests new ways in which stretchable and wearable electronics can enable humans to interface with virtual environments. Critically, this system was constructed of components costing less than $100 and did not require chemical synthesis or access to a cleanroom. It can thus be used as a test bed for materials scientists to evaluate the performance of new materials and flexible and stretchable hybrid electronics.

The Language of Glove: Wireless gesture decoder with low-power and stretchable hybrid electronics

PubMed Central

O’Connor, Timothy F.; Fach, Matthew E.; Miller, Rachel; Root, Samuel E.; Mercier, Patrick P.

2017-01-01

This communication describes a glove capable of wirelessly translating the American Sign Language (ASL) alphabet into text displayable on a computer or smartphone. The key components of the device are strain sensors comprising a piezoresistive composite of carbon particles embedded in a fluoroelastomer. These sensors are integrated with a wearable electronic module consisting of digitizers, a microcontroller, and a Bluetooth radio. Finite-element analysis predicts a peak strain on the sensors of 5% when the knuckles are fully bent. Fatigue studies suggest that the sensors successfully detect the articulation of the knuckles even when bent to their maximal degree 1,000 times. In concert with an accelerometer and pressure sensors, the glove is able to translate all 26 letters of the ASL alphabet. Lastly, data taken from the glove are used to control a virtual hand; this application suggests new ways in which stretchable and wearable electronics can enable humans to interface with virtual environments. Critically, this system was constructed of components costing less than $100 and did not require chemical synthesis or access to a cleanroom. It can thus be used as a test bed for materials scientists to evaluate the performance of new materials and flexible and stretchable hybrid electronics. PMID:28700603

NEID Port Adapter: Design and Verification Plan

NASA Astrophysics Data System (ADS)

Logsdon, Sarah E.; McElwain, Michael; McElwain, Michael W.; Gong, Qian; Bender, Chad; Halverson, Samuel; Hearty, Fred; Hunting, Emily; Jaehnig, Kurt; Liang, Ming; Mahadevan, Suvrath; Monson, A. J.; Percival, Jeffrey; Rajagopal, Jayadev; Ramsey, Lawrence; Roy, Arpita; Santoro, Fernando; Schwab, Christian; Smith, Michael; Wolf, Marsha; Wright, Jason

2018-01-01

The NEID spectrograph is an optical (380-930 nm), fiber-fed, precision Doppler spectrograph currently in development for the 3.5 m WIYN Telescope at Kitt Peak National Observatory. Designed to achieve a radial velocity precision of <30 cm/s, NEID will be sensitive enough to detect terrestrial-mass exoplanets around low-mass stars. Light from the target stars is focused by the telescope to a bent-Cassegrain port at the edge of the primary mirror mechanical support. The specialized NEID “Port Adapter” system is mounted at this bent-Cassegrain port and is responsible for delivering the incident light from the telescope to the NEID fibers. In order to provide stable, high-quality images to the science instrument, the Port Adapter houses several subcomponents designed to acquire the target stars, correct for atmospheric dispersion, stabilize the light onto the science fibers, and calibrate the spectrograph by injecting known wavelength sources such as a laser frequency comb. Here we describe the overall design of the Port Adapter and outline the development of calibration tools and an on-sky test plan to verify the performance of the atmospheric dispersion corrector (ADC). We also discuss the development of an error budget and test requirements to ensure high-precision centroiding onto the NEID science fibers using a system of coherent fiber bundles.

Alcohol sensor based on u-bent hetero-structured fiber optic

NASA Astrophysics Data System (ADS)

Patrialova, Sefi N.; Hatta, Agus M.; Sekartedjo, Sekartedjo

2016-11-01

A sensor based on a fiber optic hetero-structure to determine the concentration of alcohol has been proposed. The structure of the sensing probe in this research is a singlemode-multimode-singlemode (SMS) which bent into Ushaped and soon called as SMS u-bent. The SMS structure was chosen to get a higher sensitivity. This research utilizes the principle of multimode interference and evanescent field by modifying the cladding with various alcohol concentration. Testing of the sensor's performance has been done by measuring the sensor's power output response to the length of the SMS fiber optic, bending diameter, and alcohol concentration. Based on the experiment result, the ubent SMS fiber optic with 50 mm bending diameter and 63 mm MMF lenght has the highest sensitivity, 3.87 dB/% and the minimum resolution, 0.26 x 10-3 %.

Bent dark soliton dynamics in two spatial dimensions beyond the mean field approximation

NASA Astrophysics Data System (ADS)

Mistakidis, Simeon; Katsimiga, Garyfallia; Koutentakis, Georgios; Kevrekidis, Panagiotis; Schmelcher, Peter; Theory Group of Fundamental Processes in Quantum Physics Team

2017-04-01

The dynamics of a bented dark soliton embedded in two spatial dimensions beyond the mean-field approximation is explored. We examine the case of a single bented dark soliton comparing the mean-field approximation to a correlated approach that involves multiple orbitals. Fragmentation is generally present and significantly affects the dynamics, especially in the case of stronger interparticle interactions and in that of lower atom numbers. It is shown that the presence of fragmentation allows for the appearance of solitonic and vortex structures in the higher-orbital dynamics. In particular, a variety of excitations including dark solitons in multiple orbitals and vortex-antidark complexes is observed to arise spontaneously within the beyond mean-field dynamics. Deutsche Forschungsgemeinschaft (DFG) in the framework of the SFB 925 ``Light induced dynamics and control of correlated quantum systems''.

Human immunoglobulin E flexes between acutely bent and extended conformations

PubMed Central

Keeble, Anthony H; Wright, Michael; Cain, Katharine; Hailu, Hanna; Oxbrow, Amanda; Delgado, Jean; Shuttleworth, Lindsay K; Kao, Michael W-P; McDonnell, James M; Beavil, Andrew J; Henry, Alistair J; Sutton, Brian J

2014-01-01

Crystallographic and solution studies have shown that IgE molecules are acutely bent in their Fc region. Crystal structures reveal the Cε2 domain pair folded back onto the Cε3-Cε4 domains, but is the molecule exclusively bent or can the Cε2 domains adopt extended conformations and even “flip” from one side of the molecule to the other? We report the crystal structure of IgE-Fc captured in a fully extended, symmetrical conformation and show by molecular dynamics, calorimetry, stopped-flow kinetic, SPR and FRET analyses, that the antibody can indeed adopt such extended conformations in solution. This diversity of conformational states available to IgE-Fc offers a new perspective on IgE function in allergen recognition, as part of the B cell receptor and as a therapeutic target in allergic disease. PMID:24632569

Objectivity, Reliability, and Validity of the Bent-Knee Push-Up for College-Age Women

ERIC Educational Resources Information Center

Wood, Heather M.; Baumgartner, Ted A.

2004-01-01

The revised push-up test has been found to have good validity but it produces many zero scores for women. Maybe there should be an alternative to the revised push-up test for college-age women. The purpose of this study was to determine the objectivity, reliability, and validity for the bent-knee push-up test (executed on hands and knees) for…

History of early settlement and land use on the Bent Creek Experimental Forest Buncombe County, NC

Treesearch

William A. Nesbitt

1941-01-01

This report has been prepared for two reasons: first, it is believed that a description of past land use on the Bent Creek Experimental Forest may enable the research forester to better interpret the forest conditions as he finds them today; and second, a record of the rise and fall of a once prosperous rural community will be preserved for its future sociological...

X-ray topography as a process control tool in semiconductor and microcircuit manufacture

NASA Technical Reports Server (NTRS)

Parker, D. L.; Porter, W. A.

1977-01-01

A bent wafer camera, designed to identify crystal lattice defects in semiconductor materials, was investigated. The camera makes use of conventional X-ray topographs and an innovative slightly bent wafer which allows rays from the point source to strike all portions of the wafer simultaneously. In addition to being utilized in solving production process control problems, this camera design substantially reduces the cost per topograph.

Corrosion of NiTi Wires with Cracked Oxide Layer

NASA Astrophysics Data System (ADS)

Racek, Jan; Šittner, Petr; Heller, Luděk; Pilch, Jan; Petrenec, Martin; Sedlák, Petr

2014-07-01

Corrosion behavior of superelastic NiTi shape memory alloy wires with cracked TiO2 surface oxide layers was investigated by electrochemical corrosion tests (Electrochemical Impedance Spectroscopy, Open Circuit Potential, and Potentiodynamic Polarization) on wires bent into U-shapes of various bending radii. Cracks within the oxide on the surface of the bent wires were observed by FIB-SEM and TEM methods. The density and width of the surface oxide cracks dramatically increase with decreasing bending radius. The results of electrochemical experiments consistently show that corrosion properties of NiTi wires with cracked oxide layers (static load keeps the cracks opened) are inferior compared to the corrosion properties of the straight NiTi wires covered by virgin uncracked oxides. Out of the three methods employed, the Electrochemical Impedance Spectroscopy seems to be the most appropriate test for the electrochemical characterization of the cracked oxide layers, since the impedance curves (Nyquist plot) of differently bent NiTi wires can be associated with increasing state of the surface cracking and since the NiTi wires are exposed to similar conditions as the surfaces of NiTi implants in human body. On the other hand, the potentiodynamic polarization test accelerates the corrosion processes and provides clear evidence that the corrosion resistance of bent superelastic NiTi wires degrades with oxide cracking.

Probing Structural Perturbation in a Bent Molecular Crystal with Synchrotron Infrared Microspectroscopy and Periodic Density Functional Theory Calculations.

PubMed

Pejov, Ljupčo; Panda, Manas K; Moriwaki, Taro; Naumov, Panče

2017-02-15

The range of unit cell orientations generated at the kink of a bent single crystal poses unsurmountable challenges with diffraction analysis and limits the insight into the molecular-scale mechanism of bending. On a plastically bent crystal of hexachlorobenzene, it is demonstrated here that spatially resolved microfocus infrared spectroscopy using synchrotron radiation can be applied in conjunction with periodic density functional theory calculations to predict spectral changes or to extract information on structural changes that occur as a consequence of bending. The approach reproduces well the observed trends, such as the wall effects, and provides estimations of the vibrational shifts, unit cell deformations, and intramolecular parameters. Generally, expansion of the lattice induces red-shift while compression induces larger blue-shift of the characteristic ν(C-C) and ν(C-Cl) modes. Uniform or non-uniform expansion or contraction of the unit cell of 0.1 Å results in shifts of several cm -1 , whereas deformation of the cell of 0.5° at the unique angle causes shifts of <0.5 cm -1 . Since this approach does not include parameters related to the actual stimulus by which the deformation has been induced, it can be generalized and applied to other mechanically, photochemically, or thermally bent crystals.

Simulation of orientational coherent effects via Geant4

NASA Astrophysics Data System (ADS)

Bagli, E.; Asai, M.; Brandt, D.; Dotti, A.; Guidi, V.; Verderi, M.; Wright, D.

2017-10-01

Simulation of orientational coherent effects via Geant4 beam manipulation of high-and very-high-energy particle beams is a hot topic in accelerator physics. Coherent effects of ultra-relativistic particles in bent crystals allow the steering of particle trajectories thanks to the strong electrical field generated between atomic planes. Recently, a collimation experiment with bent crystals was carried out at the CERN-LHC, paving the way to the usage of such technology in current and future accelerators. Geant4 is a widely used object-oriented tool-kit for the Monte Carlo simulation of the interaction of particles with matter in high-energy physics. Moreover, its areas of application include also nuclear and accelerator physics, as well as studies in medical and space science. We present the first Geant4 extension for the simulation of orientational effects in straight and bent crystals for high energy charged particles. The model allows the manipulation of particle trajectories by means of straight and bent crystals and the scaling of the cross sections of hadronic and electromagnetic processes for channeled particles. Based on such a model, an extension of the Geant4 toolkit has been developed. The code and the model have been validated by comparison with published experimental data regarding the deflection efficiency via channeling and the variation of the rate of inelastic nuclear interactions.

Detecting double compressed MPEG videos with the same quantization matrix and synchronized group of pictures structure

NASA Astrophysics Data System (ADS)

Aghamaleki, Javad Abbasi; Behrad, Alireza

2018-01-01

Double compression detection is a crucial stage in digital image and video forensics. However, the detection of double compressed videos is challenging when the video forger uses the same quantization matrix and synchronized group of pictures (GOP) structure during the recompression history to conceal tampering effects. A passive approach is proposed for detecting double compressed MPEG videos with the same quantization matrix and synchronized GOP structure. To devise the proposed algorithm, the effects of recompression on P frames are mathematically studied. Then, based on the obtained guidelines, a feature vector is proposed to detect double compressed frames on the GOP level. Subsequently, sparse representations of the feature vectors are used for dimensionality reduction and enrich the traces of recompression. Finally, a support vector machine classifier is employed to detect and localize double compression in temporal domain. The experimental results show that the proposed algorithm achieves the accuracy of more than 95%. In addition, the comparisons of the results of the proposed method with those of other methods reveal the efficiency of the proposed algorithm.

Emergence of a confined state in a weakly bent wire

NASA Astrophysics Data System (ADS)

Granot, Er'El

2002-06-01

In this paper we use a simple straightforward technique to investigate the emergence of a bound state in a weakly bent wire. We show that the bend behaves like an infinitely shallow potential well, and in the limit of small bending angle (φ<<1) and low energy the bend can be presented by a simple one-dimensional δ-function potential, V(x)=-(2(cb)φ2)δ(x) where cb≅2.1.

Electromagnetic dipole moments of charged baryons with bent crystals at the LHC

NASA Astrophysics Data System (ADS)

Bagli, E.; Bandiera, L.; Cavoto, G.; Guidi, V.; Henry, L.; Marangotto, D.; Martinez Vidal, F.; Mazzolari, A.; Merli, A.; Neri, N.; Ruiz Vidal, J.

2017-12-01

We propose a unique program of measurements of electric and magnetic dipole moments of charm, beauty and strange charged baryons at the LHC, based on the phenomenon of spin precession of channeled particles in bent crystals. Studies of crystal channeling and spin precession of positively- and negatively-charged particles are presented, along with feasibility studies and expected sensitivities for the proposed experiment using a layout based on the LHCb detector.

High-resolution Raman microscopy of curled carbon nanotubes

NASA Astrophysics Data System (ADS)

Ko, Hyunhyub; Pikus, Yuri; Jiang, Chaoyang; Jauss, Andrea; Hollricher, Olaf; Tsukruk, Vladimir V.

2004-09-01

Patterned carbon nanotube assemblies with bent nanotube bundles were investigated with combined atomic force microscopy and confocal Raman imaging spectroscopy to identify conditions of carbon nanotubes in the bent state. We showed that the tangential G mode on Raman spectra systematically shifts downward upon nanotube bending as was predicted earlier. This lower frequency shift is attributed to the tensile stress, which results in the loosening of C -C bonds in the outer nanotube walls.

Residual stocking not seriously reduced by logging damage from thinning of West Virginia cherry-maple stands

Treesearch

Neil I. Lamson; H. Clay Smith; Gary W. Miller

1984-01-01

In north-central West Virginia, unmanaged 60-year-old cherry-maple stands were thinned to 75, 60, and 45 percent residual stocking. Cut trees were skidded tree length by a rubber-tired skidder. Logging destroyed or severely bent over 22, 23, and 45 percent of the unmarked stems in the 75, 60, and 45 percent stocked plots. Because 99 percent of the destroyed and bent...

Electrostatic potential in a bent piezoelectric nanowire with consideration of size-dependent piezoelectricity and semiconducting characterization.

PubMed

Wang, K F; Wang, B L

2018-06-22

Determining the electric potential in a bent piezoelectric nanowire (NW) is a fundamental issue of nanogenerators and nanopiezotronics. The combined influence of the flexoelectric effect, the semiconducting performance and the angle of atomic force microscope (AFM) tip has never been studied previously and will be investigated in this paper. The exact solution for the electric potential of a bent piezoelectric semiconductor NW is derived. The electric potential of the present model with consideration of flexoelectric effect varies along the length of the NW and is different from that of the classical piezoelectric model. Flexoelectric effect enhances but the semiconducting performance reduces the electric potential of the NW. In addition, it is found that if the angle of the AFM tip reaches 30°, the error of the electric potential obtained from the model ignored the effect of the angle of the AFM tip is almost 16%, which is unacceptable.

Electrostatic potential in a bent piezoelectric nanowire with consideration of size-dependent piezoelectricity and semiconducting characterization

NASA Astrophysics Data System (ADS)

Wang, K. F.; Wang, B. L.

2018-06-01

Determining the electric potential in a bent piezoelectric nanowire (NW) is a fundamental issue of nanogenerators and nanopiezotronics. The combined influence of the flexoelectric effect, the semiconducting performance and the angle of atomic force microscope (AFM) tip has never been studied previously and will be investigated in this paper. The exact solution for the electric potential of a bent piezoelectric semiconductor NW is derived. The electric potential of the present model with consideration of flexoelectric effect varies along the length of the NW and is different from that of the classical piezoelectric model. Flexoelectric effect enhances but the semiconducting performance reduces the electric potential of the NW. In addition, it is found that if the angle of the AFM tip reaches 30°, the error of the electric potential obtained from the model ignored the effect of the angle of the AFM tip is almost 16%, which is unacceptable.

Two-dimensional fluid dynamics in a sharply bent channel: Laminar flow, separation bubble, and vortex dynamics

NASA Astrophysics Data System (ADS)

Matsumoto, Daichi; Fukudome, Koji; Wada, Hirofumi

2016-10-01

Understanding the hydrodynamic properties of fluid flow in a curving pipe and channel is important for controlling the flow behavior in technologies and biomechanics. The nature of the resulting flow in a bent pipe is extremely complicated because of the presence of a cross-stream secondary flow. In an attempt to disentangle this complexity, we investigate the fluid dynamics in a bent channel via the direct numerical simulation of the Navier-Stokes equation in two spatial dimensions. We exploit the absence of secondary flow from our model and systematically investigate the flow structure along the channel as a function of both the bend angle and Reynolds number of the laminar-to-turbulent regime. We numerically suggest a scaling relation between the shape of the separation bubble and the flow conductance, and construct an integrated phase diagram.

Droplets on bent fibers

NASA Astrophysics Data System (ADS)

Weyer, Floriane; Pan, Zhao; Pitt, William; Truscott, Tadd; Vandewalle, Nicolas

Droplets on fibers are part of our everyday lives. Many phenomena involve drops and fibers such as the formation of dew droplets on a spiderweb, the trapping of water droplets on cactus spines or the motion of droplets on wetted moss hairs. These topics have been widely studied. In particular, Lorenceau et al. determined the critical volume of a water droplet hanging on a horizontal fiber. Here, we address a similar question : we try to find out the maximum droplet size on bent fibers, which are able to hold significantly more water than horizontal fibers. Indeed, we noticed that, in nature, some specific plants can hold large rain droplets thanks to their Y-shaped leaves. We try to mimic these structures with nylon fibers, of different diameters, bent with various angles. For each set-up, the critical water volume is determined. Finally, we propose models of the physics involved in determining droplet size that could be implemented in future fiber-based microfluidic devices.

Focusing effect of bent GaAs crystals for γ-ray Laue lenses: Monte Carlo and experimental results

NASA Astrophysics Data System (ADS)

Virgilli, E.; Frontera, F.; Rosati, P.; Bonnini, E.; Buffagni, E.; Ferrari, C.; Stephen, J. B.; Caroli, E.; Auricchio, N.; Basili, A.; Silvestri, S.

2016-02-01

We report on results of observation of the focusing effect from the planes (220) of Gallium Arsenide (GaAs) crystals. We have compared the experimental results with the Monte Carlo simulations of the focusing capability of GaAs tiles performed with a dedicated ray-tracer. The GaAs tiles were bent using a lapping process developed at the cnr/imem - Parma (Italy) in the framework of the laue project, funded by ASI, dedicated to build a broad band Laue lens prototype for astrophysical applications in the hard X-/soft γ-ray energy range (80-600 keV). We present and discuss the results obtained from their characterization, mainly in terms of focusing capability. Bent crystals will significantly increase the signal to noise ratio of a telescope based on a Laue lens, consequently leading to an unprecedented enhancement of sensitivity with respect to the present non focusing instrumentation.

Comparison of photon organ and effective dose coefficients for PIMAL stylized phantom in bent positions in standard irradiation geometries.

PubMed

Dewji, Shaheen; Reed, K Lisa; Hiller, Mauritius

2017-08-01

Computational phantoms with articulated arms and legs have been constructed to enable the estimation of radiation dose in different postures. Through a graphical user interface, the Phantom wIth Moving Arms and Legs (PIMAL) version 4.1.0 software can be employed to articulate the posture of a phantom and generate a corresponding input deck for the Monte Carlo N-Particle (MCNP) radiation transport code. In this work, photon fluence-to-dose coefficients were computed using PIMAL to compare organ and effective doses for a stylized phantom in the standard upright position with those for phantoms in realistic work postures. The articulated phantoms represent working positions including fully and half bent torsos with extended arms for both the male and female reference adults. Dose coefficients are compared for both the upright and bent positions across monoenergetic photon energies: 0.05, 0.1, 0.5, 1.0, and 5.0 MeV. Additionally, the organ doses are compared across the International Commission on Radiological Protection's standard external radiation exposure geometries: antero-posterior, postero-anterior, left and right lateral, and isotropic (AP, PA, LLAT, RLAT, and ISO). For the AP and PA irradiation geometries, differences in organ doses compared to the upright phantom become more profound with increasing bending angles and have doses largely overestimated for all organs except the brain in AP and bladder in PA. In LLAT and RLAT irradiation geometries, energy deposition for organs is more likely to be underestimated compared to the upright phantom, with no overall change despite increased bending angle. The ISO source geometry did not cause a significant difference in absorbed organ dose between the different phantoms, regardless of position. Organ and effective fluence-to-dose coefficients are tabulated. In the AP geometry, the effective dose at the 45° bent position is overestimated compared to the upright phantom below 1 MeV by as much as 27% and 82% in the 90° position. The effective dose in the 45° bent position was comparable to that in the 90° bent position for the LLAT and RLAT irradiation geometries. However, the upright phantom underestimates the effective dose to PIMAL in the LLAT and RLAT geometries by as much as 30% at 50 keV.

Activation of CO2 by supported Cu clusters.

PubMed

Iyemperumal, Satish Kumar; Deskins, N Aaron

2017-11-01

Catalytic reduction of carbon dioxide to useful chemicals is a potent way to mitigate this greenhouse gas, but the challenge lies in finding active reduction catalysts. Using density functional theory we studied CO 2 activation over TiO 2 -supported Cu clusters of size 1-4 atoms. The linear to bent transformation of CO 2 is necessary for activation, and we found that all the clusters stabilized bent CO 2 , along with a significant gain of electrons on the CO 2 (indicative of activation). On all the TiO 2 supported Cu clusters, the interfacial sites were found to stabilize the bent CO 2 adsorption, where the active site of adsorption on Cu dimer, trimer and tetramer was on the Cu atom farthest away from the TiO 2 surface. Particularly, the Cu dimer stabilized bent CO 2 very strongly, although this species was found to be unstable on the surface. A synthesis technique that could stabilize the Cu dimer could therefore lead to a very active catalyst. Furthermore we found (using vibrational and charge analysis) that the active sites for the CO 2 activation predominantly had 0 and +1 oxidation states; the oxidation state of Cu is known to directly affect CO 2 reduction activity. Our study shows TiO 2 -supported small Cu clusters can be active catalysts for CO 2 reduction and also provides further motivation for theoretical and experimental studies of metal clusters.

Studies on scintillating fiber response

NASA Astrophysics Data System (ADS)

Albers, D.; Bisplinghoff, J.; Bollmann, R.; Büßer, K.; Cloth, P.; Diehl, O.; Dohrmann, F.; Drüke, V.; Engelhardt, H. P.; Ernst, J.; Eversheim, P. D.; Filges, D.; Gasthuber, M.; Gebel, R.; Greiff, J.; Groß, A.; Groß-Hardt, R.; Heine, A.; Heider, S.; Hinterberger, F.; Igelbrink, M.; Jahn, R.; Jeske, M.; Langkau, R.; Lindlein, J.; Maier, R.; Maschuw, R.; Mayer-Kuckuk, T.; Mertler, G.; Metsch, B.; Mosel, F.; Müller, M.; Münstermann, M.; Paetz gen. Schieck, H.; Petry, H. R.; Prasuhn, D.; Rohdjeß, H.; Rosendaal, D.; Roß, U.; von Rossen, P.; Scheid, H.; Schirm, N.; Schulz-Rojahn, M.; Schwandt, F.; Scobel, W.; Steeg, B.; Sterzenbach, G.; Trelle, H. J.; Wellinghausen, A.; Wiedmann, W.; Woller, K.; Ziegler, R.

1996-02-01

Scintillating fibers of type Bicron BCF-12 with 2 × 2 mm 2 cross section, up to 600 mm length, and PMMA cladding have been tested, in conjunction with the multi-channel photomultiplier Hamamatsu R 4760, with minimum ionizing electrons. The impact of cladding, extramural absorbers and/or wrapping on the light attenuation and photoelectron yield is studied in detail. Fibers have been circularly bent with radii of 171 mm and arranged in two layers to bundles forming granulated scintillator rings. Their performance in the EDDA experiment at COSY for detection of high energy protons revealed typically more than 9 (6) photoelectrons per fiber from bundles with (without) mirror on the rear side, guaranteeing detection efficiencies >99% and full compatibility with corresponding solid scintillator rings. The time resolution of 3.4 ns FWHM per fiber read out is essentially due to the R 4760.

Nonharmonic oscillations of nanosized cantilevers due to quantum-size effects

NASA Astrophysics Data System (ADS)

Olsen, Martin; Gradin, Per; Lindefelt, Ulf; Olin, Håkan

2010-02-01

Using a one-dimensional jellium model and standard beam theory we calculate the spring constant of a vibrating nanowire cantilever. By using the asymptotic energy eigenvalues of the standing electron waves over the nanometer-sized cross-section area, the change in the grand canonical potential is calculated and hence the force and the spring constant. As the wire is bent more electron states fits in its cross section. This has an impact on the spring “constant” which oscillates slightly with the bending of the wire. In this way we obtain an amplitude-dependent resonance frequency of the oscillations that should be detectable.

Single-wire dye-sensitized solar cells wrapped by carbon nanotube film electrodes.

PubMed

Zhang, Sen; Ji, Chunyan; Bian, Zhuqiang; Liu, Runhua; Xia, Xinyuan; Yun, Daqin; Zhang, Luhui; Huang, Chunhui; Cao, Anyuan

2011-08-10

Conventional fiber-shaped polymeric or dye-sensitized solar cells (DSSCs) are usually made into a double-wire structure, in which a secondary electrode wire (e.g., Pt) was twisted along the primary core wire consisting of active layers. Here, we report highly flexible DSSCs based on a single wire, by wrapping a carbon nanotube film around Ti wire-supported TiO(2) tube arrays as the transparent electrode. Unlike a twisted Pt electrode, the CNT film ensures full contact with the underlying active layer, as well as uniform illumination along circumference through the entire DSSC. The single-wire DSSC shows a power conversion efficiency of 1.6% under standard illumination (AM 1.5, 100 mW/cm(2)), which is further improved to more than 2.6% assisted by a second conventional metal wire (Ag or Cu). Our DSSC wires are stable and can be bent to large angles up to 90° reversibly without performance degradation.

New Beamlines For Protein Crystallography At The EMBL-Outstation Hamburg

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

Hermes, C.; Gehrmann, T.; Jahn, D.

2004-05-12

Three new beamlines for Protein Crystallography were built up on a bending magnet fan of the DORIS III storage ring. A 10 mrad wide fan of white Synchrotron Radiation (SR) is evenly distributed among 3 individual stations: X12, a central, wavelength-tunable station intended for anomalous scattering experiments (MAD) and fixed wavelength, high intensity stations symmetrically on either side. The fixed wavelength beamlines X11 and X13 comprise triangular, asymmetrically cut Si (111) monochromators as horizontally focusing optical elements. The tunable station is based on a fixed-exit, horizontally focusing double crystal monochromator system. Vertical focusing is achieved on all three lines bymore » trapezoidal shaped, continuous Rh-coated mirrors which can be dynamically bent. In all three lines the X-ray beam can be examined at various points on its way through the optical system by removable screens and PIN-diode based intensity monitors. Purpose built crystallographic end-stations complete the set-up. The design of individual components and their performance will be described.« less

Multilayer and grazing incidence X-ray/EUV optics; Proceedings of the Meeting, San Diego, CA, July 22-24, 1991

NASA Technical Reports Server (NTRS)

Hoover, Richard B. (Editor)

1992-01-01

The present conference discusses the Advanced X-ray Astrophysics Facility (AXAF) calibration by means of synchrotron radiation and its X-ray reflectivity, X-ray scattering measurements from thin-foil X-ray mirrors, lobster-eye X-ray optics using microchannel plates, space-based interferometry at EUV and soft X-ray wavelengths, a water-window imaging X-ray telescope, a graded d-spacing multilayer telescope for high energy X-ray astronomy, photographic films for the multispectral solar telescope array, a soft X-ray ion chamber, and the development of hard X-ray optics. Also discussed are X-ray spectroscopy with multilayered optics, a slit aperture for monitoring X-ray experiments, an objective double-crystal spectrometer, a Ly-alpha coronagraph/polarimeter, tungsten/boron nitride multilayers for XUV optical applications, the evaluation of reflectors for soft X-ray optics, the manufacture of elastically bent crystals and multilayer mirrors, and selective photodevices for the VUV.

Performance Evaluation of Strain Gauge Printed Using Automatic Fluid Dispensing System on Conformal Substrates

NASA Astrophysics Data System (ADS)

Khairilhijra Khirotdin, Rd.; Faridzuan Ngadiron, Mohamad; Adzeem Mahadzir, Muhammad; Hassan, Nurhafizzah

2017-08-01

Smart textiles require flexible electronics that can withstand daily stresses like bends and stretches. Printing using conductive inks provides the flexibility required but the current printing techniques suffered from ink incompatibility, limited of substrates to be printed with and incompatible with conformal substrates due to its rigidity and low flexibility. An alternate printing technique via automatic fluid dispensing system is proposed and its performances on printing strain gauge on conformal substrates were evaluated to determine its feasibility. Process parameters studied including printing speed, deposition height, curing time and curing temperature. It was found that the strain gauge is proven functional as expected since different strains were induced when bent on variation of bending angles and curvature radiuses from designated bending fixtures. The average change of resistances were doubled before the strain gauge starts to break. Printed strain gauges also exhibited some excellence elasticity as they were able to resist bending up to 70° angle and 3 mm of curvature radius.

Probing the elastic limit of DNA bending

PubMed Central

Le, Tung T.; Kim, Harold D.

2014-01-01

Sharp bending of double-stranded DNA (dsDNA) plays an essential role in genome structure and function. However, the elastic limit of dsDNA bending remains controversial. Here, we measured the opening rates of small dsDNA loops with contour lengths ranging between 40 and 200 bp using single-molecule Fluorescence Resonance Energy Transfer. The relationship of loop lifetime to loop size revealed a critical transition in bending stress. Above the critical loop size, the loop lifetime changed with loop size in a manner consistent with elastic bending stress, but below it, became less sensitive to loop size, indicative of softened dsDNA. The critical loop size increased from ∼60 bp to ∼100 bp with the addition of 5 mM magnesium. We show that our result is in quantitative agreement with the kinkable worm-like chain model, and furthermore, can reproduce previously reported looping probabilities of dsDNA over the range between 50 and 200 bp. Our findings shed new light on the energetics of sharply bent dsDNA. PMID:25122748

Scintillating fiber-based photon beam profiler for the Jefferson Lab tagged photon beam line

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

Zorn, C.; Barbosa, F.J.; Freyberger, A.

2000-10-01

A scintillating fiber hodoscope has been built for use as a photon beam profiler in the bremsstrahlung tagged photon beam in Hall B of the Thomas Jefferson National Accelerator Facility (Jefferson Lab). The device consists of a linear array of 64 2-2 mm2 scintillating fibers glued to a corresponding set of light guide fibers. Both fiber types use double-clad technology for maximum intensity. The light guide fibers are gently bent into a square array of holes and air-gap coupled to four compact position-sensitive photomultipliers (16 channel Hamamatsu R5900-M16). Custom electronics amplifies and converts the analog outputs to ECL pulses whichmore » are counted by VME-based scalars. The device consisting of the fibers, photomultipliers, and electronics is sealed within a light-tight aluminum box. Two modules make up a beam imaging 2-D system. The system has been tested successfully during an experimental run« less

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

Dong, Wen-Wen; Xia, Liang; Peng, Zhen

Under solvothermal conditions, the reactions of Co{sup II}/Zn{sup II} ions with bent ligand 3-(pyridin-4-yl)-5-(pyrazin-2-yl)-1H-1,2,4-triazole (4-Hpzpt) afford two compounds {[M(4-pzpt)_2] guest}{sub n} (guest=H{sub 2}O, M=Co{sup II} (1), Zn{sup II} (2)). Both compounds are the thermally and hydrolytically robust 4-connected 3D NbO framework, which formed by double helical chains to give rise to 1D hollow nanochannel with uncoordinated nitrogens completely exposed on the pore surface. Compound 1 exhibits improved N{sub 2}, CO{sub 2} and H{sub 2} uptake capacities, while compound 2 displays the strong luminescent emission with obvious red shift. - Graphical abstract: Two 2-fold interpenetrated NbO-type MOFs with 1D nanochannel weremore » synthesized. Compound 1 exhibits improved N{sub 2}, CO{sub 2} and H{sub 2} uptake capacities, while compound 2 displays the strong fluorescent emission with obvious red shift. Display Omitted.« less

Mechanical and electro-optical properties of unconventional liquid crystal systems

NASA Astrophysics Data System (ADS)

Liao, Guangxun

Four types of unconventional liquid crystal systems - amphotropic glycolipids; novel bent-core liquid crystals, bent-core liquid crystal and glycolipid mixtures, and colloidal crystal-liquid crystal systems - were studied and characterized by polarizing microscopy, electrical current, digital scanning calorimetry, and dielectric spectroscopy. Thermotropic properties of glycolipids show a number of unusual properties, most notably high (60-120) relative dielectric constants mainly proportional to the number of polar sugar heads. The relaxation of this dielectric mode is found to be governed by the hydrogen bonding between sugar heads. Studies on novel bent-core liquid crystals reveal a new optically isotropic ferroelectric phase, molecular chirality-induced polarity, and transitions between molecular chirality and polarity driven phases. Mixtures of several bent-core substances with nematic, polar SmA and SmC phases, and a simple amphiphilic sugar lipid with SmA mesophase found to obey the well known miscibility rules, i.e. the sugar lipid mixes best with the polar SmA bent-core material. In addition, the chiral sugar lipid was found to induce tilt to the non-tilted polar SmA phase, which represents a new direction among the chirality--polarity--tilt relations. The effects of the surface properties and electric fields were studied on various colloid particles--and liquid crystal systems. It is found that the surface properties (hydrophobicity, roughness, rubbing) of the substrates are important in determining the size and symmetry of colloidal crystals. The director field of the liquid crystal infiltrated in the colloid crystals can be rendered both random and uniform along one of the crystallographic axis. We present the first observations of DC electric-field-induced rotational and translational motion of finite particles in liquid crystals. The electrorotation is essentially identical to the well - known Quincke rotation, which in liquid crystals triggers an additional translational motion at higher fields. Analysis of the electro-rotation and translations provides new ways to probe local rheological properties of liquid crystals.

Development of X-ray spectroscopic polarimetry with bent Si crystals and CFRP substrate

NASA Astrophysics Data System (ADS)

Iizuka, Ryo; Izumiya, Takanori; Tsuboi, Yohko

2016-07-01

The light from celestial objects includes four important quantities; images, time variation, energy spectrum, and polarization. In the field of X-ray astronomy, the capabilities of the former three have remarkably developed. On the other hand, the progress for the polarimetry is considerably delayed because of technical difficulties. In order to make a breakthrough in the field of X-ray polarimetry, we have developed a new type of optics for X-ray polarimetry. The system is collecting Bragg crystal with large area and very high sensitivity for the polarization dedicated to Fe-K lines. We adopt the 400 re ection of Si(100) crystals with high sensitivity for the polarization around Fe-K lines (6 7 keV), and bent the crystals with the wide X-ray band and high S/N ratio. Furthermore, to install small area of CCD to non-focal plane, it also has the spectroscopic capability with the better resolution than that of general X-ray CCD. Our previous development was to bent Si crystals to the cylindrical shape of circle and parabola with the DLC deposition. However, for the better optics for the X-ray polarimetry, the shape should be the paraboloid of revolution to collect X-rays with high S/N ratio. We searched for the method to bent the Si crystals to the shape of the paraboloid of revolution. We devised the method to mold the crystal and the CFRP substrate simultaneously pushed to the sophisticated foundation with the paraboloid of revolution. We developed the prototype of about 8 inch in radius of one-quater size. The crystals was also bent in the circumferential direction. Therefore, the image capability examined with optical parallel beam is 0.6 degree. In this thesis, we discussed the new design for X-ray spectroscopic polarimetry, the evaluation of image capability.

Effects of molecular chirality on self-assembly and switching in liquid crystals at the cross-over between rod-like and bent shapes.

PubMed

Ocak, Hale; Poppe, Marco; Bilgin-Eran, Belkız; Karanlık, Gürkan; Prehm, Marko; Tschierske, Carsten

2016-09-21

A bent-core compound derived from a 4-cyanoresorcinol core unit with two terephthalate based rod-like wings and carrying chiral 3,7-dimethyloctyloxy side chains has been synthesized in racemic and enantiomerically pure form and characterized by polarizing microscopy, differential scanning calorimetry, X-ray diffraction and electro-optical investigations to study the influence of molecular chirality on the superstructural chirality and polar order in lamellar liquid crystalline phases. Herein we demonstrate that the coupling of molecular chirality with superstructural layer chirality in SmCsPF domain phases (forming energetically distinct diastereomeric pairs) can fix the tilt direction and thus stabilize synpolar order, leading to bistable ferroelectric switching in the SmC* phases of the (S)-enantiomer, whereas tristable modes determine the switching of the racemate. Moreover, the mechanism of electric field induced molecular reorganization changes from a rotation around the molecular long axis in the racemate to a rotation on the tilt-cone for the (S)-enantiomer. At high temperature the enantiomer behaves like a rod-like molecule with a chirality induced ferroelectric SmC* phase and an electroclinic effect in the SmA'* phase. At reduced temperature sterically induced polarization, due to the bent molecular shape, becomes dominating, leading to much higher polarization values, thus providing access to high polarization ferroelectric materials with weakly bent compounds having only "weakly chiral" stereogenic units. Moreover, the field induced alignment of the SmCsPF(()*()) domains gives rise to a special kind of electroclinic effect appearing even in the absence of molecular chirality. Comparison with related compounds indicates that the strongest effects of chirality appear for weakly bent molecules with a relatively short coherence length of polar order, whereas for smectic phases with long range polar order the effects of the interlayer interfaces can override the chirality effects.

Underwater Facilities and Inspections and Assessments at Naval Air Station, Pensacola, Florida.

DTIC Science & Technology

1983-01-01

hairline crack at 4-43 pile cap (vertical face) bent 34 27 Pier, 303 - Spalled concrete and exposed rebar 4-44 in pile cap bent 38 28 Pier 303 - Typical...of steel sheet pile 4-53 3’ below concrete encasement at station 83+25 37 Pier 303 - Exposed rebar and spall in concrete 4-54 encasement at station 83... corrosion and concrete deterioration due to exposure to the elements. 3.3 Inspection Equipment The following equipment was employed by diving engineers

Effects of Herbal Supplements on PTSD-Induced Changes in Rat Behavior & Brain Gene Expression

DTIC Science & Technology

2014-06-10

Corporation; 2008. 14. Bent S. Herbal medicine in the United States: review of efficacy, safety, and regulation: grand rounds at University of...Ceremuga, Thomas COL (Ret) USU Project Number: N10-P12 70. Bent S: Herbal medicine in the United States: review of efficacy, safety, and regulation...2012;177(7):814-822. 135. Ang-Lee MK, Moss J, Yuan CS. Herbal medicines and perioperative care. Jama. Jul 11 2001;286(2):208-216. 136. Jankowsi K

Acoustic Liners for Turbine Engines

NASA Technical Reports Server (NTRS)

Jones, Michael G (Inventor); Grady, Joseph E (Inventor); Heidmann, James D. (Inventor); Kiser, James D. (Inventor); Miller, Christopher (Inventor)

2016-01-01

An improved acoustic liner for turbine engines is disclosed. The acoustic liner may include a straight cell section including a plurality of cells with straight chambers. The acoustic liner may also include a bent cell section including one or more cells that are bent to extend chamber length without increasing the overall height of the acoustic liner by the entire chamber length. In some cases, holes are placed between cell chambers in addition to bending the cells, or instead of bending the cells.

The past, present, and future of hockey-stick-shaped liquid crystals

NASA Astrophysics Data System (ADS)

Choi, E.-Joon

2014-02-01

Recently, the liquid crystalline materials with a bent-core mesogen have attracted attentions because their interesting properties such as polarity and biaxiality of the mesophase. There are several types of bent-core mesogenic structures have been reported, for instance, banana-shaped, V-shaped molecules, boomerang-shaped, hockey stick-shaped, and Yshaped molecules. In this study, the liquid crystals and the reactive mesogens with the hockey-stick shaped mesogens will be described concerning with the structure-property relationship.

Forming of the Most Convenient Bent Constructional Elements with a Permissible Strength Given

NASA Astrophysics Data System (ADS)

Fligiel, M.

2014-11-01

In the present study, the limiting values are determined of the criteria quantities of optimal forming of the most convenient bent supporting structure for the case of static loads in the range of the Hooke's law applicability. As the criterion of the most convenient constructional element, the following were accepted: the smallest length of the activity of internal forces as well as the equal potential and the gradient of the potential energy of elastic deformation at each point of the constructional element.

Bats adjust their pulse emission rates with swarm size in the field.

PubMed

Lin, Yuan; Abaid, Nicole; Müller, Rolf

2016-12-01

Flying in swarms, e.g., when exiting a cave, could pose a problem to bats that use an active biosonar system because the animals could risk jamming each other's biosonar signals. Studies from current literature have found different results with regard to whether bats reduce or increase emission rate in the presence of jamming ultrasound. In the present work, the number of Eastern bent-wing bats (Miniopterus fuliginosus) that were flying inside a cave during emergence was estimated along with the number of signal pulses recorded. Over the range of average bat numbers present in the recording (0 to 14 bats), the average number of detected pulses per bat increased with the average number of bats. The result was interpreted as an indication that the Eastern bent-wing bats increased their emission rate and/or pulse amplitude with swarm size on average. This finding could be explained by the hypothesis that the bats might not suffer from substantial jamming probabilities under the observed density regimes, so jamming might not have been a limiting factor for their emissions. When jamming did occur, the bats could avoid it through changing the pulse amplitude and other pulse properties such as duration or frequency, which has been suggested by other studies. More importantly, the increased biosonar activities may have addressed a collision-avoidance challenge that was posed by the increased swarm size.

Reduction and analysis of VLA maps for 281 radio-loud quasars using the UNLV Cray Y-MP supercomputer

NASA Technical Reports Server (NTRS)

Ding, Ailian; Hintzen, Paul; Weistrop, Donna; Owen, Frazer

1993-01-01

The identification of distorted radio-loud quasars provides a potentially very powerful tool for basic cosmological studies. If large morphological distortions are correlated with membership of the quasars in rich clusters of galaxies, optical observations can be used to identify rich clusters of galaxies at large redshifts. Hintzen, Ulvestad, and Owen (1983, HUO) undertook a VLA A array snapshot survey at 20 cm of 123 radio-loud quasars, and they found that among triple sources in their sample, 17 percent had radio axes which were bent more than 20 deg and 5 percent were bent more than 40 deg. Their subsequent optical observations showed that excess galaxy densities within 30 arcsec of 6 low-redshift distorted quasars were on average 3 times as great as those around undistorted quasars (Hintzen 1984). At least one of the distorted quasars observed, 3C275.1, apparently lies in the first-ranked galaxy at the center of a rich cluster of galaxies (Hintzen and Romanishin, 1986). Although their sample was small, these results indicated that observations of distorted quasars could be used to identify clusters of galaxies at large redshifts. The purpose of this project is to increase the available sample of distorted quasars to allow optical detection of a significant sample of quasar-associated clusters of galaxies at large redshifts.

Detection of Ammonia-Oxidizing Bacteria (AOB) Using a Porous Silicon Optical Biosensor Based on a Multilayered Double Bragg Mirror Structure.

PubMed

Zhang, Hongyan; Lv, Jie; Jia, Zhenhong

2018-01-01

We successfully demonstrate a porous silicon (PS) double Bragg mirror by electrochemical etching at room temperature as a deoxyribonucleic acid (DNA) label-free biosensor for detecting ammonia-oxidizing bacteria (AOB). Compared to various other one-dimension photonic crystal configurations of PS, the double Bragg mirror structure is quite easy to prepare and exhibits interesting optical properties. The width of high reflectivity stop band of the PS double Bragg mirror is about 761 nm with a sharp and deep resonance peak at 1328 nm in the reflectance spectrum, which gives a high sensitivity and distinguishability for sensing performance. The detection sensitivity of such a double Bragg mirror structure is illustrated through the investigation of AOB DNA hybridization in the PS pores. The redshifts of the reflectance spectra show a good linear relationship with both complete complementary and partial complementary DNA. The lowest detection limit for complete complementary DNA is 27.1 nM and the detection limit of the biosensor for partial complementary DNA is 35.0 nM, which provides the feasibility and effectiveness for the detection of AOB in a real environment. The PS double Bragg mirror structure is attractive for widespread biosensing applications and provides great potential for the development of optical applications.

Group delay spread analysis of coupled-multicore fibers: A comparison between weak and tight bending conditions

NASA Astrophysics Data System (ADS)

Fujisawa, Takeshi; Saitoh, Kunimasa

2017-06-01

Group delay spread of coupled three-core fiber is investigated based on coupled-wave theory. The differences between supermode and discrete core mode models are thoroughly investigated to reveal applicability of both models for specific fiber bending condition. A macrobending with random twisting is taken into account for random modal mixing in the fiber. It is found that for weakly bent condition, both supermode and discrete core mode models are applicable. On the other hand, for strongly bent condition, the discrete core mode model should be used to account for increased differential modal group delay for the fiber without twisting and short correlation length, which were experimentally observed recently. Results presented in this paper indicate the discrete core mode model is superior to the supermode model for the analysis of coupled-multicore fibers for various bent condition. Also, for estimating GDS of coupled-multicore fiber, it is critically important to take into account the fiber bending condition.

Nanowires Bending over Backward from Strain Partitioning in Asymmetric Core-Shell Heterostructures.

PubMed

Lewis, Ryan B; Corfdir, Pierre; Küpers, Hanno; Flissikowski, Timur; Brandt, Oliver; Geelhaar, Lutz

2018-04-11

The flexibility and quasi-one-dimensional nature of nanowires offer wide-ranging possibilities for novel heterostructure design and strain engineering. In this work, we realize arrays of extremely and controllably bent nanowires comprising lattice-mismatched and highly asymmetric core-shell heterostructures. Strain sharing across the nanowire heterostructures is sufficient to bend vertical nanowires over backward to contact either neighboring nanowires or the substrate itself, presenting new possibilities for designing nanowire networks and interconnects. Photoluminescence spectroscopy on bent-nanowire heterostructures reveals that spatially varying strain fields induce charge carrier drift toward the tensile-strained outside of the nanowires, and that the polarization response of absorbed and emitted light is controlled by the bending direction. This unconventional strain field is employed for light emission by placing an active region of quantum dots at the outer side of a bent nanowire to exploit the carrier drift and tensile strain. These results demonstrate how bending in nanoheterostructures opens up new degrees of freedom for strain and device engineering.

In vivo longitudinal micro-CT study of bent long limb bones in rat offspring.

PubMed

De Schaepdrijver, Luc; Delille, Peter; Geys, Helena; Boehringer-Shahidi, Christian; Vanhove, Christian

2014-07-01

Micro-computed X-ray tomography (micro-CT) has been reported as a reliable method to assess ex vivo rat and rabbit fetal skeletons in embryo-fetal developmental toxicity studies. Since micro-CT is a non-invasive imaging modality it has the potential for longitudinal, in vivo investigation of postnatal skeletal development. This is the first paper using micro-CT to assess the reversibility of drug-induced bent long bones in a longitudinal study from birth to early adulthood in rat offspring. Analysis of the scans obtained on postnatal Day 0, 7, 21 and 80 showed complete recovery or repair of the bent long limb bones (including the scapula) within the first 3 weeks. When assessing risk the ability to demonstrate recovery is highly advantageous when interpreting such transient skeletal change. In summary, in vivo micro-CT of small laboratory animals can aid in non-clinical safety assessment, particularly for specific mechanistic purposes or to address a particular concern in developmental biology. Copyright © 2014 Elsevier Inc. All rights reserved.

Study of the efficiency for ion transfer through bent capillaries.

PubMed

Chen, Tsung-Chi; Xu, Wei; Garimella, Sandilya; Ouyang, Zheng

2012-11-01

Discontinuous atmospheric pressure interfaces (DAPIs) with bent capillaries represent a highly simplified and flexible means for introducing ions into a vacuum manifold for mass analysis or gas phase ion reactions. In this work, a series of capillaries of different radians and curvatures were used with DAPI for studying the impact of the capillary bending on the ion transfer. The variation of transfer efficiency was systematically characterized for dry and solvated ions. The efficiency loss for dry ions was less than one order of magnitude, even with a three-turn bent capillary. The transfer of solvated ions generated by electrospray was found to be minimally impacted by the bending of the transfer capillary. For multiply protonated ions, the transfer efficiency for ions at lower charge states could be relatively well retained, presumably due to the lower reactivity associated with proton transfer reaction and the compensation in intensity by conversion of ions at higher charge states. Copyright © 2012 John Wiley & Sons, Ltd.

Classifying Radio Galaxies with the Convolutional Neural Network

NASA Astrophysics Data System (ADS)

Aniyan, A. K.; Thorat, K.

2017-06-01

We present the application of a deep machine learning technique to classify radio images of extended sources on a morphological basis using convolutional neural networks (CNN). In this study, we have taken the case of the Fanaroff-Riley (FR) class of radio galaxies as well as radio galaxies with bent-tailed morphology. We have used archival data from the Very Large Array (VLA)—Faint Images of the Radio Sky at Twenty Centimeters survey and existing visually classified samples available in the literature to train a neural network for morphological classification of these categories of radio sources. Our training sample size for each of these categories is ˜200 sources, which has been augmented by rotated versions of the same. Our study shows that CNNs can classify images of the FRI and FRII and bent-tailed radio galaxies with high accuracy (maximum precision at 95%) using well-defined samples and a “fusion classifier,” which combines the results of binary classifications, while allowing for a mechanism to find sources with unusual morphologies. The individual precision is highest for bent-tailed radio galaxies at 95% and is 91% and 75% for the FRI and FRII classes, respectively, whereas the recall is highest for FRI and FRIIs at 91% each, while the bent-tailed class has a recall of 79%. These results show that our results are comparable to that of manual classification, while being much faster. Finally, we discuss the computational and data-related challenges associated with the morphological classification of radio galaxies with CNNs.

High sensitive and direct fluorescence detection of single viral DNA sequences by integration of double strand probes onto microgels particles.

PubMed

Aliberti, A; Cusano, A M; Battista, E; Causa, F; Netti, P A

2016-02-21

A novel class of probes for fluorescence detection was developed and combined to microgel particles for a high sensitive fluorescence detection of nucleic acids. A double strand probe with an optimized fluorescent-quencher couple was designed for the detection of different lengths of nucleic acids (39 nt and 100 nt). Such probe proved efficient in target detection in different contests and specific even in presence of serum proteins. The conjugation of double strand probes onto polymeric microgels allows for a sensitive detection of DNA sequences from HIV, HCV and SARS corona viruses with a LOD of 1.4 fM, 3.7 fM and 1.4 fM, respectively, and with a dynamic range of 10(-9)-10(-15) M. Such combination enhances the sensitivity of the detection of almost five orders of magnitude when compared to the only probe. The proposed platform based on the integration of innovative double strand probe into microgels particles represents an attractive alternative to conventional sensitive DNA detection technologies that rely on amplifications methods.

The role of load-carrying in the evolution of modern body proportions.

PubMed

Wang, W-J; Crompton, R H

2004-05-01

The first unquestionably bipedal early human ancestors, the species Australopithecus afarensis, were markedly different to ourselves in body proportions, having a long trunk and short legs. Some have argued that 'chimpanzee-like' features such as these suggest a 'bent-hip, bent-knee' (BHBK) posture would have been adopted during gait. Computer modelling studies, however, indicate that this early human ancestor could have walked in a reasonably efficient upright posture, whereas BHBK posture would have nearly doubled the mechanical energy cost of locomotion, as it does the physiological cost of locomotion in ourselves. More modern body proportions first appear at around 1.8-1.5 Ma, with Homo ergaster (early African Homo erectus), represented by the Nariokotome skeleton KNM-WT 15000, in which the legs were considerably longer in relation to the trunk than they are in human adults, although this skeleton represents an adolescent. Several authors have suggested that this morphology would have allowed faster, more endurant walking. But during the same period, the archaeological record indicates a sharp rise in distances over which stone tools or raw materials are transported. Is this coincidental, or can load-carrying also be implicated in selection for a more modern morphology? Computer simulations of loaded walking, verified against kinetic data for humans, show that BHBK gait is even more ineffective while load-carrying. However, walking erect, the Nariokotome individual could have carried loads of 10-15% body mass for less cost, relative to body size, than AL 288-1 walking erect but unloaded. In fact, to the extent that our sample of humans is typical, KNM-WT 15000 would have had better mechanical effectiveness in bearing light loads on the back than modern human adults. Thus, selection for effectiveness in load-carrying, as well as in endurant walking, is indeed likely to have been implicated in the evolution of modern body proportions.

Norman M. Dott, master of hypothalamic craniopharyngioma surgery: the decisive mentoring of Harvey Cushing and Percival Bailey at Peter Bent Brigham Hospital.

PubMed

Prieto, Ruth; Pascual, José M

2017-10-01

Norman McOmish Dott (1897-1973) developed surgical neurology in Edinburgh, Scotland, and was a scholar of worldwide renown. One of Dott's most notable contributions to neurosurgery was his understanding of hypothalamic physiology, mostly acquired through the comprehensive study of patients with lesions involving this region of the diencephalon, particularly craniopharyngiomas (CPs). Recognition of symptoms caused by hypothalamic disturbances allowed him to predict the accurate anatomical relationships between CPs and the hypothalamus, despite the rudimentary radiological methods available during the 1930s. His sophisticated knowledge permitted Dott to perform radical removals of CPs originating within the third ventricle floor with acceptable success. Between 1934 and 1937, he operated on 4 CP cases originating in the hypothalamus, achieving a satisfactory postoperative outcome in 3 of the 4 patients. Aware of the strong attachment of hypothalamic CPs to the infundibulo-tuberal area, Dott used a double transbasal and transventricular approach to these lesions, a strategy providing an optimal view and control of the tumor boundaries. The decisive mentorship of several legendary figures of physiology and neurosurgery greatly influenced Dott's surgical evolution. The experimental pituitary gland work he performed with Sir Edward Sharpey-Schäfer at the beginning of his career stirred Dott's curiosity about the issue of hypothalamus-pituitary relationships. As a result, he decided to move to Peter Bent Brigham Hospital (Boston, Massachusetts) in 1923, to train in neurosurgery and neuropathology under the guidance of the leaders in these fields, Harvey Williams Cushing (1869-1939) and Percival Sylvester Bailey (1892-1973). They inspired the young Dott and shared with him their clinical and pathological expertise, in addition to their surgical strategies for best approaching and removing these challenging tumors. In time, Dott would come to surpass his mentors. This paper aims to credit Norman M. Dott for his decisive, modern contributions to hypothalamic CP surgery.

The role of load-carrying in the evolution of modern body proportions

PubMed Central

Wang, W -J; Crompton, R H

2004-01-01

The first unquestionably bipedal early human ancestors, the species Australopithecus afarensis, were markedly different to ourselves in body proportions, having a long trunk and short legs. Some have argued that ′chimpanzee-like′ features such as these suggest a ‘bent-hip, bent-knee’ (BHBK) posture would have been adopted during gait. Computer modelling studies, however, indicate that this early human ancestor could have walked in a reasonably efficient upright posture, whereas BHBK posture would have nearly doubled the mechanical energy cost of locomotion, as it does the physiological cost of locomotion in ourselves. More modern body proportions first appear at around 1.8–1.5 Ma, with Homo ergaster (early African Homo erectus), represented by the Nariokotome skeleton KNM-WT 15000, in which the legs were considerably longer in relation to the trunk than they are in human adults, although this skeleton represents an adolescent. Several authors have suggested that this morphology would have allowed faster, more endurant walking. But during the same period, the archaeological record indicates a sharp rise in distances over which stone tools or raw materials are transported. Is this coincidental, or can load-carrying also be implicated in selection for a more modern morphology? Computer simulations of loaded walking, verified against kinetic data for humans, show that BHBK gait is even more ineffective while load-carrying. However, walking erect, the Nariokotome individual could have carried loads of 10–15% body mass for less cost, relative to body size, than AL 288-1 walking erect but unloaded. In fact, to the extent that our sample of humans is typical, KNM-WT 15000 would have had better mechanical effectiveness in bearing light loads on the back than modern human adults. Thus, selection for effectiveness in load-carrying, as well as in endurant walking, is indeed likely to have been implicated in the evolution of modern body proportions. PMID:15198704

Visual performance on detection tasks with double-targets of the same and different difficulty.

PubMed

Chan, Alan H S; Courtney, Alan J; Ma, C W

2002-10-20

This paper reports a study of measurement of horizontal visual sensitivity limits for 16 subjects in single-target and double-targets detection tasks. Two phases of tests were conducted in the double-targets task; targets of the same difficulty were tested in phase one while targets of different difficulty were tested in phase two. The range of sensitivity for the double-targets test was found to be smaller than that for single-target in both the same and different target difficulty cases. The presence of another target was found to affect performance to a marked degree. Interference effect of the difficult target on detection of the easy one was greater than that of the easy one on the detection of the difficult one. Performance decrement was noted when correct percentage detection was plotted against eccentricity of target in both the single-target and double-targets tests. Nevertheless, the non-significant correlation found between the performance for the two tasks demonstrated that it was impossible to predict quantitatively ability for detection of double targets from the data for single targets. This indicated probable problems in generalizing data for single target visual lobes to those for multiple targets. Also lobe area values obtained from measurements using a single-target task cannot be applied in a mathematical model for situations with multiple occurrences of targets.

Observation of polar order and thermochromic behaviour in a chiral bent-core system exhibiting exotic mesophases due to superstructural frustration.

PubMed

Punjani, Vidhika; Mohiuddin, Golam; Kaur, Supreet; Khan, Raj Kumar; Ghosh, Sharmistha; Pal, Santanu Kumar

2018-04-03

A new approach accompanied by superstructural frustration is reported. By attaching a cholesterol moiety directly to the central bent-core system it displayed exotic BPIII, BPII/I, Ncyb*, TGBA, SmAPA, SmA and SmX phases as shown by X-ray scattering results. While higher homologues of the series exhibited spontaneous formation of polar order (Ps ∼ 61 nC cm-2) upon applied voltage, the lower homologues showed thermochromic behaviour which can also be trapped via temperature quenching.

Channeling and radiation of 855 MeV electrons and positrons in straight and bent tungsten (1 1 0) crystals

NASA Astrophysics Data System (ADS)

Shen, H.; Zhao, Q.; Zhang, F. S.; Sushko, Gennady B.; Korol, Andrei V.; Solov'yov, Andrey V.

2018-06-01

Planar channeling of 855 MeV electrons and positrons in straight and bent tungsten (1 1 0) crystal is simulated by means of the MBN EXPLORER software package. The results of simulations for a broad range of bending radii are analyzed in terms of the channel acceptance, dechanneling length, and spectral distribution of the emitted radiation. Comparison of the results with predictions of other theories as well as with the data for (1 1 0) oriented diamond, silicon and germanium crystals is carried out.

Innovative remotely-controlled bending device for thin silicon and germanium crystals

NASA Astrophysics Data System (ADS)

De Salvador, D.; Carturan, S.; Mazzolari, A.; Bagli, E.; Bandiera, L.; Durighello, C.; Germogli, G.; Guidi, V.; Klag, P.; Lauth, W.; Maggioni, G.; Romagnoni, M.; Sytov, A.

2018-04-01

Steering of negatively charged particle beams below 1 GeV has demonstrated to be possible with thin bent silicon and germanium crystals. A newly designed mechanical holder was used for bending crystals, since it allows a remotely-controlled adjustment of crystal bending and compensation of unwanted torsion. Bent crystals were installed and tested at the MAMI Mainz MIcrotron to achieve steering of 0.855-GeV electrons at different bending radii. We report the description and characterization of the innovative bending device developed at INFN Laboratori Nazionali di Legnaro (LNL).

Resonator coiling in thermoacoustic engines

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

Olson, J.R.; Swift, G.W.

1995-11-01

Coiling the resonator of a thermoacoustic engine is one way to try to minimize the engine`s size. However, flow in bent pipes is known to alter the fluid flow pattern because of centrifugal forces. Theory and measurements will be presented on the energy dissipation caused by oscillating flow in curved pipes. Measurements have been taken using free oscillations of liquids in U-tubes, and using a thermoacoustic engine with straight and bent resonators. [Work supported by the TTI program of the US Department of Energy, and by the Tektronix Corporation.

On Weak and Strong 2k- bent Boolean Functions

DTIC Science & Technology

2016-01-01

U.S.A. Email: pstanica@nps.edu Abstract—In this paper we introduce a sequence of discrete Fourier transforms and define new versions of bent...denotes the complex conjugate of z. An important tool in our analysis is the discrete Fourier transform , known in Boolean functions literature, as Walsh...Hadamard, or Walsh–Hadamard transform , which is the func- tion Wf : Fn2 → C, defined by Wf (u) = 2− n 2 ∑ x∈Vn (−1)f(x)⊕u·x. Any f ∈ Bn can be

Graph Eigenvalues and Walsh Spectrum of Boolean Functions

DTIC Science & Technology

2006-08-28

Same as Report (SAR) 18. NUMBER OF PAGES 15 19a. NAME OF RESPONSIBLE PERSON a. REPORT unclassified b. ABSTRACT unclassified c . THIS PAGE...class of all affine functions on Vn. We say that f satisfies the propagation criterion (PC) with respect to c if∑ x∈Vn f(x)⊕ f(x⊕ c ) = 2n−1. (2) If f...any c with wt( c ) ≤ s, we say that f satisfies PC(s), and if s = n, then we say that f is a bent function. Recall that the Hamming weight of bent

A Unimodal Model for Double Observer Distance Sampling Surveys.

PubMed

Becker, Earl F; Christ, Aaron M

2015-01-01

Distance sampling is a widely used method to estimate animal population size. Most distance sampling models utilize a monotonically decreasing detection function such as a half-normal. Recent advances in distance sampling modeling allow for the incorporation of covariates into the distance model, and the elimination of the assumption of perfect detection at some fixed distance (usually the transect line) with the use of double-observer models. The assumption of full observer independence in the double-observer model is problematic, but can be addressed by using the point independence assumption which assumes there is one distance, the apex of the detection function, where the 2 observers are assumed independent. Aerially collected distance sampling data can have a unimodal shape and have been successfully modeled with a gamma detection function. Covariates in gamma detection models cause the apex of detection to shift depending upon covariate levels, making this model incompatible with the point independence assumption when using double-observer data. This paper reports a unimodal detection model based on a two-piece normal distribution that allows covariates, has only one apex, and is consistent with the point independence assumption when double-observer data are utilized. An aerial line-transect survey of black bears in Alaska illustrate how this method can be applied.

Cost-Effectiveness of Double Reading versus Single Reading of Mammograms in a Breast Cancer Screening Programme

PubMed Central

Posso, Margarita; Carles, Misericòrdia; Rué, Montserrat; Puig, Teresa; Bonfill, Xavier

2016-01-01

Objectives The usual practice in breast cancer screening programmes for mammogram interpretation is to perform double reading. However, little is known about its cost-effectiveness in the context of digital mammography. Our purpose was to evaluate the cost-effectiveness of double reading versus single reading of digital mammograms in a population-based breast cancer screening programme. Methods Data from 28,636 screened women was used to establish a decision-tree model and to compare three strategies: 1) double reading; 2) double reading for women in their first participation and single reading for women in their subsequent participations; and 3) single reading. We calculated the incremental cost-effectiveness ratio (ICER), which was defined as the expected cost per one additionally detected cancer. We performed a deterministic sensitivity analysis to test the robustness of the ICER. Results The detection rate of double reading (5.17‰) was similar to that of single reading (4.78‰; P = .768). The mean cost of each detected cancer was €8,912 for double reading and €8,287 for single reading. The ICER of double reading versus single reading was €16,684. The sensitivity analysis showed variations in the ICER according to the sensitivity of reading strategies. The strategy that combines double reading in first participation with single reading in subsequent participations was ruled out due to extended dominance. Conclusions From our results, double reading appears not to be a cost-effective strategy in the context of digital mammography. Double reading would eventually be challenged in screening programmes, as single reading might entail important net savings without significantly changing the cancer detection rate. These results are not conclusive and should be confirmed in prospective studies that investigate long-term outcomes like quality adjusted life years (QALYs). PMID:27459663

Sensitivity and Specificity of Double-Track Sign in the Detection of Transverse Sinus Stenosis: A Multicenter Retrospective Study

PubMed Central

Zhu, De-Sheng; Fu, Jue; Zhang, Yi; Xie, Chong; Wang, Xiao-Qing; Zhang, Yue; Yang, Jie; Li, Shi-Xu; Liu, Xiao-Bei; Wan, Zhi-Wen; Dong, Qiang; Guan, Yang-Tai

2015-01-01

Background Transverse sinus stenosis (TSS) is common among patients with cerebral venous sinus thrombosis. No previous studies have reported on double-track sign detected on axial Gd-enhanced T1WI in TSS. This study aimed to determine the sensitivity and specificity of the double-track sign in the detection of TSS. Methods We retrospectively reviewed medical records of 383 patients with transverse sinus thrombosis (TST) and 30 patients with normal transverse sinus from 5 participating hospitals in china from January 2008 to June 2014. 167 feasible transverse sinuses included in this study were categorized into TSS (n = 76), transverse sinus occlusion (TSO) (n = 52) and transverse sinus normal (TSN) groups (n = 39) according to imaging diagnosis on digital subtraction angiography (DSA) or magnetic resonance venography (MRV). Double-track sign on axial Gd-enhanced T1WI was compared among the three groups. Sensitivity and specificity of double-track sign in detection of TSS were calculated, with final imaging diagnosis of TSS on DSA or MRV as the reference standard. Results Of 383 patients with TST recruited over a 6.5-year period, 128 patients were enrolled in the study, 255 patients were excluded because of insufficient clinical data, imaging finding and delay time, and 30 matched patients with normal transverse sinus were enrolled in the control group. Therefore, double-track sign assessment was conducted in 167 available transverse sinuses of 158 patients. Of the 76 sinuses in TSS group, 51 had double-track sign. Of the other 91 sinuses in TSO and TSN groups, 3 had a false-positive double-track sign. Thus, double-track sign on axial Gd-enhanced T1WI was 67.1% (95% CI 55.3–77.2) sensitive and 96.7% (95% CI 89.9–99.1) specific for detection of TSS. Conclusions The double-track sign on axial Gd-enhanced T1WI is highly specific and moderate sensitive for detection of TSS. Nevertheless, it could be a direct sign and might provide an early clue for TSS. PMID:26291452

Sensitivity and Specificity of Double-Track Sign in the Detection of Transverse Sinus Stenosis: A Multicenter Retrospective Study.

PubMed

Zhu, De-Sheng; Fu, Jue; Zhang, Yi; Xie, Chong; Wang, Xiao-Qing; Zhang, Yue; Yang, Jie; Li, Shi-Xu; Liu, Xiao-Bei; Wan, Zhi-Wen; Dong, Qiang; Guan, Yang-Tai

2015-01-01

Transverse sinus stenosis (TSS) is common among patients with cerebral venous sinus thrombosis. No previous studies have reported on double-track sign detected on axial Gd-enhanced T1WI in TSS. This study aimed to determine the sensitivity and specificity of the double-track sign in the detection of TSS. We retrospectively reviewed medical records of 383 patients with transverse sinus thrombosis (TST) and 30 patients with normal transverse sinus from 5 participating hospitals in china from January 2008 to June 2014. 167 feasible transverse sinuses included in this study were categorized into TSS (n = 76), transverse sinus occlusion (TSO) (n = 52) and transverse sinus normal (TSN) groups (n = 39) according to imaging diagnosis on digital subtraction angiography (DSA) or magnetic resonance venography (MRV). Double-track sign on axial Gd-enhanced T1WI was compared among the three groups. Sensitivity and specificity of double-track sign in detection of TSS were calculated, with final imaging diagnosis of TSS on DSA or MRV as the reference standard. Of 383 patients with TST recruited over a 6.5-year period, 128 patients were enrolled in the study, 255 patients were excluded because of insufficient clinical data, imaging finding and delay time, and 30 matched patients with normal transverse sinus were enrolled in the control group. Therefore, double-track sign assessment was conducted in 167 available transverse sinuses of 158 patients. Of the 76 sinuses in TSS group, 51 had double-track sign. Of the other 91 sinuses in TSO and TSN groups, 3 had a false-positive double-track sign. Thus, double-track sign on axial Gd-enhanced T1WI was 67.1% (95% CI 55.3-77.2) sensitive and 96.7% (95% CI 89.9-99.1) specific for detection of TSS. The double-track sign on axial Gd-enhanced T1WI is highly specific and moderate sensitive for detection of TSS. Nevertheless, it could be a direct sign and might provide an early clue for TSS.

Classifying Radio Galaxies with the Convolutional Neural Network

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

Aniyan, A. K.; Thorat, K.

We present the application of a deep machine learning technique to classify radio images of extended sources on a morphological basis using convolutional neural networks (CNN). In this study, we have taken the case of the Fanaroff–Riley (FR) class of radio galaxies as well as radio galaxies with bent-tailed morphology. We have used archival data from the Very Large Array (VLA)—Faint Images of the Radio Sky at Twenty Centimeters survey and existing visually classified samples available in the literature to train a neural network for morphological classification of these categories of radio sources. Our training sample size for each of these categoriesmore » is ∼200 sources, which has been augmented by rotated versions of the same. Our study shows that CNNs can classify images of the FRI and FRII and bent-tailed radio galaxies with high accuracy (maximum precision at 95%) using well-defined samples and a “fusion classifier,” which combines the results of binary classifications, while allowing for a mechanism to find sources with unusual morphologies. The individual precision is highest for bent-tailed radio galaxies at 95% and is 91% and 75% for the FRI and FRII classes, respectively, whereas the recall is highest for FRI and FRIIs at 91% each, while the bent-tailed class has a recall of 79%. These results show that our results are comparable to that of manual classification, while being much faster. Finally, we discuss the computational and data-related challenges associated with the morphological classification of radio galaxies with CNNs.« less

Geochemistry of fluid phases and sediments: Relevance to hydrothermal circulation in Middle Valley, ODP Legs 139 and 169

USGS Publications Warehouse

Gieskes, J.M.; Simoneit, B.R.T.; Shanks, Wayne C.; Goodfellow, W.D.; James, R.H.; Baker, P.A.; Ishibashi, J.-I.

2002-01-01

Geochemical and isotopic studies of pore fluids and solid phases recovered from the Dead Dog and Bent Hill hydrothermal sites in Middle Valley (Ocean Drilling Program Leg 169) have been compared with similar data obtained previously from these sites during Ocean Drilling Program Leg 139. Although generally the hydrothermal systems reflect non-steady state conditions, the data allow an assessment of the history of the hydrothermal processes. Sediment K/A1 ratios as well as the distribution of anhydrite in the sediments suggest that the Dead Dog hydrothermal field has been, and still is, active. In contrast, similar data in the Bent Hill hydrothermal field indicate a waning of hydrothermal activity. Pore fluid and hydrothermal vent data in the Dead Dog hydrothermal field are similar in nature to the data collected during ODP Leg 139. In the area of the Bent Hill sulfide deposit, however, the pore water data indicate that recent wholesale flushing of the sediment column with relatively unaltered seawater has obliterated a previous record of hydrothermal activity in the pore fluids. Data from the deepest part of Hole 1035A in the Bent Hill locality show the presence of hydrothermal fluids at greater depths in this area. This suggests the origin of the hydrothermal fluids found to be emanating from Hole 1035F, which constitutes one of the first man made hydrothermal vents in the Middle Valley hydrothermal system. Similarly, CORKed Hole 858G, because of seal failures, has acted as a hydrothermal vent, with sulfide deposits forming inside the CORK. ?? 2002 Elsevier Science Ltd. All rights reserved.

Photoinduced Changes of Surface Topography in Amorphous, Liquid-Crystalline, and Crystalline Films of Bent-Core Azobenzene-Containing Substance.

PubMed

Bobrovsky, Alexey; Mochalov, Konstantin; Oleinikov, Vladimir; Solovyeva, Daria; Shibaev, Valery; Bogdanova, Yulia; Hamplová, Vĕra; Kašpar, Miroslav; Bubnov, Alexej

2016-06-09

Recently, photofluidization and mass-transfer effects have gained substantial interest because of their unique abilities of photocontrolled manipulation with material structure and physicochemical properties. In this work, the surface topographies of amorphous, nematic, and crystalline films of an azobenzene-containing bent-core (banana-shaped) compound were studied using a special experimental setup combining polarizing optical microscopy and atomic force microscopy. Spin-coating or rapid cooling of the samples enabled the formation of glassy amorphous or nematic films of the substance. The effects of UV and visible-light irradiation on the surface roughness of the films were investigated. It was found that UV irradiation leads to the fast isothermal transition of nematic and crystalline phases into the isotropic phase. This effect is associated with E-Z photoisomerization of the compound accompanied by a decrease of the anisometry of the bent-core molecules. Focused polarized visible-light irradiation (457.9 nm) results in mass-transfer phenomena and induces the formation of so-called "craters" in amorphous and crystalline films of the substance. The observed photofluidization and mass-transfer processes allow glass-forming bent-core azobenzene-containing substances to be considered for the creation of promising materials with photocontrollable surface topographies. Such compounds are of principal importance for the solution of a broad range of problems related to the investigation of surface phenomena in colloid and physical chemistry, such as surface modification for chemical and catalytic reactions, predetermined morphology of surfaces and interfaces in soft matter, and chemical and biochemical sensing.

Influence of snow shovel shaft configuration on lumbosacral biomechanics during a load-lifting task.

PubMed

Lewinson, Ryan T; Rouhi, Gholamreza; Robertson, D Gordon E

2014-03-01

Lower-back injury from snow shovelling may be related to excessive joint loading. Bent-shaft snow shovels are commonly available for purchase; however, their influence on lower back-joint loading is currently not known. Therefore, the purpose of this study was to compare L5/S1 extension angular impulses between a bent-shaft and a standard straight-shaft snow shovel. Eight healthy subjects participated in this study. Each completed a simulated snow-lifting task in a biomechanics laboratory with each shovel design. A standard motion analysis procedure was used to determine L5/S1 angular impulses during each trial, as well as peak L5/S1 extension moments and peak upper body flexion angle. Paired-samples t-tests (α = 0.05) were used to compare variables between shovel designs. Correlation was used to determine the relationship between peak flexion and peak moments. Results of this study show that the bent-shaft snow shovel reduced L5/S1 extension angular impulses by 16.5% (p = 0.022), decreased peak moments by 11.8% (p = 0.044), and peak flexion by 13.0% (p = 0.002) compared to the straight-shaft shovel. Peak L5/S1 extension moment magnitude was correlated with peak upper body flexion angle (r = 0.70). Based on these results, it is concluded that the bent-shaft snow shovel can likely reduce lower-back joint loading during snow shovelling, and thus may have a role in snow shovelling injury prevention. Copyright © 2013 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Biaxial order parameter in the homologous series of orthogonal bent-core smectic liquid crystals

NASA Astrophysics Data System (ADS)

Sreenilayam, S.; Panarin, Y. P.; Vij, J. K.; Osipov, M.; Lehmann, A.; Tschierske, C.

2013-07-01

The fundamental parameter of the uniaxial liquid crystalline state that governs nearly all of its physical properties is the primary orientational order parameter (S) for the long axes of molecules with respect to the director. The biaxial liquid crystals (LCs) possess biaxial order parameters depending on the phase symmetry of the system. In this paper we show that in the first approximation a biaxial orthogonal smectic phase can be described by two primary order parameters: S for the long axes and C for the ordering of the short axes of molecules. The temperature dependencies of S and C are obtained by the Haller's extrapolation technique through measurements of the optical birefringence and biaxiality on a nontilted polar antiferroelectric (Sm-APA) phase of a homologous series of LCs built from the bent-core achiral molecules. For such a biaxial smectic phase both S and C, particularly the temperature dependency of the latter, are being experimentally determined. Results show that S in the orthogonal smectic phase composed of bent cores is higher than in Sm-A calamatic LCs and C is also significantly large.

Computational Predictions of the Performance Wright 'Bent End' Propellers

NASA Technical Reports Server (NTRS)

Wang, Xiang-Yu; Ash, Robert L.; Bobbitt, Percy J.; Prior, Edwin (Technical Monitor)

2002-01-01

Computational analysis of two 1911 Wright brothers 'Bent End' wooden propeller reproductions have been performed and compared with experimental test results from the Langley Full Scale Wind Tunnel. The purpose of the analysis was to check the consistency of the experimental results and to validate the reliability of the tests. This report is one part of the project on the propeller performance research of the Wright 'Bent End' propellers, intend to document the Wright brothers' pioneering propeller design contributions. Two computer codes were used in the computational predictions. The FLO-MG Navier-Stokes code is a CFD (Computational Fluid Dynamics) code based on the Navier-Stokes Equations. It is mainly used to compute the lift coefficient and the drag coefficient at specified angles of attack at different radii. Those calculated data are the intermediate results of the computation and a part of the necessary input for the Propeller Design Analysis Code (based on Adkins and Libeck method), which is a propeller design code used to compute the propeller thrust coefficient, the propeller power coefficient and the propeller propulsive efficiency.

Long, elliptically bent, active X-ray mirrors with slope errors <200 nrad.

PubMed

Nistea, Ioana T; Alcock, Simon G; Kristiansen, Paw; Young, Adam

2017-05-01

Actively bent X-ray mirrors are important components of many synchrotron and X-ray free-electron laser beamlines. A high-quality optical surface and good bending performance are essential to ensure that the X-ray beam is accurately focused. Two elliptically bent X-ray mirror systems from FMB Oxford were characterized in the optical metrology laboratory at Diamond Light Source. A comparison of Diamond-NOM slope profilometry and finite-element analysis is presented to investigate how the 900 mm-long mirrors sag under gravity, and how this deformation can be adequately compensated using a single, spring-loaded compensator. It is shown that two independent mechanical actuators can accurately bend the trapezoidal substrates to a range of elliptical profiles. State-of-the-art residual slope errors of <200 nrad r.m.s. are achieved over the entire elliptical bending range. High levels of bending repeatability (ΔR/R = 0.085% and 0.156% r.m.s. for the two bending directions) and stability over 24 h (ΔR/R = 0.07% r.m.s.) provide reliable beamline performance.

40 CFR 270.17 - Specific part B information requirements for surface impoundments.

Code of Federal Regulations, 2010 CFR

2010-07-01

... double liner and leak (leachate) detection, collection, and removal system, if the surface impoundment... double liners and a leak detection, collection, and removal system or alternative design is sought as... detection system is located in a saturated zone, submit detailed plans and an engineering report explaining...

Single shot, double differential spectral measurements of inverse Compton scattering in the nonlinear regime

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

Sakai, Y.; Gadjev, I.; Hoang, P.

Inverse Compton scattering (ICS) is a unique mechanism for producing fast pulses$-$picosecond and below$-$of bright photons, ranging from x to γ rays. These nominally narrow spectral bandwidth electromagnetic radiation pulses are efficiently produced in the interaction between intense, well-focused electron and laser beams. The spectral characteristics of such sources are affected by many experimental parameters, with intense laser effects often dominant. A laser field capable of inducing relativistic oscillatory motion may give rise to harmonic generation and, importantly for the present work, nonlinear redshifting, both of which dilute the spectral brightness of the radiation. As the applications enabled by thismore » source often depend sensitively on its spectra, it is critical to resolve the details of the wavelength and angular distribution obtained from ICS collisions. With this motivation, we present an experimental study that greatly improves on previous spectral measurement methods based on x-ray K -edge filters, by implementing a multilayer bent-crystal x-ray spectrometer. In tandem with a collimating slit, this method reveals a projection of the double differential angular-wavelength spectrum of the ICS radiation in a single shot. The measurements enabled by this diagnostic illustrate the combined off-axis and nonlinear-field-induced redshifting in the ICS emission process. The spectra obtained illustrate in detail the strength of the normalized laser vector potential, and provide a nondestructive measure of the temporal and spatial electron-laser beam overlap.« less

Single shot, double differential spectral measurements of inverse Compton scattering in the nonlinear regime

DOE PAGES

Sakai, Y.; Gadjev, I.; Hoang, P.; ...

2017-06-05

Inverse Compton scattering (ICS) is a unique mechanism for producing fast pulses$-$picosecond and below$-$of bright photons, ranging from x to γ rays. These nominally narrow spectral bandwidth electromagnetic radiation pulses are efficiently produced in the interaction between intense, well-focused electron and laser beams. The spectral characteristics of such sources are affected by many experimental parameters, with intense laser effects often dominant. A laser field capable of inducing relativistic oscillatory motion may give rise to harmonic generation and, importantly for the present work, nonlinear redshifting, both of which dilute the spectral brightness of the radiation. As the applications enabled by thismore » source often depend sensitively on its spectra, it is critical to resolve the details of the wavelength and angular distribution obtained from ICS collisions. With this motivation, we present an experimental study that greatly improves on previous spectral measurement methods based on x-ray K -edge filters, by implementing a multilayer bent-crystal x-ray spectrometer. In tandem with a collimating slit, this method reveals a projection of the double differential angular-wavelength spectrum of the ICS radiation in a single shot. The measurements enabled by this diagnostic illustrate the combined off-axis and nonlinear-field-induced redshifting in the ICS emission process. The spectra obtained illustrate in detail the strength of the normalized laser vector potential, and provide a nondestructive measure of the temporal and spatial electron-laser beam overlap.« less

A high resolution and large solid angle x-ray Raman spectroscopy end-station at the Stanford Synchrotron Radiation Lightsource

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

Sokaras, D.; Nordlund, D.; Weng, T.-C.

2012-04-15

We present a new x-ray Raman spectroscopy end-station recently developed, installed, and operated at the Stanford Synchrotron Radiation Lightsource. The end-station is located at wiggler beamline 6-2 equipped with two monochromators-Si(111) and Si(311) as well as collimating and focusing optics. It consists of two multi-crystal Johann type spectrometers arranged on intersecting Rowland circles of 1 m diameter. The first one, positioned at the forward scattering angles (low-q), consists of 40 spherically bent and diced Si(110) crystals with 100 mm diameters providing about 1.9% of 4{pi} sr solid angle of detection. When operated in the (440) order in combination with themore » Si (311) monochromator, an overall energy resolution of 270 meV is obtained at 6462.20 eV. The second spectrometer, consisting of 14 spherically bent Si(110) crystal analyzers (not diced), is positioned at the backward scattering angles (high-q) enabling the study of non-dipole transitions. The solid angle of this spectrometer is about 0.9% of 4{pi} sr, with a combined energy resolution of 600 meV using the Si (311) monochromator. These features exceed the specifications of currently existing relevant instrumentation, opening new opportunities for the routine application of this photon-in/photon-out hard x-ray technique to emerging research in multidisciplinary scientific fields, such as energy-related sciences, material sciences, physical chemistry, etc.« less

Double-pulse standoff laser-induced breakdown spectroscopy for versatile hazardous materials detection

NASA Astrophysics Data System (ADS)

Gottfried, Jennifer L.; De Lucia, Frank C.; Munson, Chase A.; Miziolek, Andrzej W.

2007-12-01

We have developed a double-pulse standoff laser-induced breakdown spectroscopy (ST-LIBS) system capable of detecting a variety of hazardous materials at tens of meters. The use of a double-pulse laser improves the sensitivity and selectivity of ST-LIBS, especially for the detection of energetic materials. In addition to various metallic and plastic materials, the system has been used to detect bulk explosives RDX and Composition-B, explosive residues, biological species such as the anthrax surrogate Bacillus subtilis, and chemical warfare simulants at 20 m. We have also demonstrated the discrimination of explosive residues from various interferents on an aluminum substrate.

Quantitative performance measurements of bent crystal Laue analyzers for X-ray fluorescence spectroscopy.

PubMed

Karanfil, C; Bunker, G; Newville, M; Segre, C U; Chapman, D

2012-05-01

Third-generation synchrotron radiation sources pose difficult challenges for energy-dispersive detectors for XAFS because of their count rate limitations. One solution to this problem is the bent crystal Laue analyzer (BCLA), which removes most of the undesired scatter and fluorescence before it reaches the detector, effectively eliminating detector saturation due to background. In this paper experimental measurements of BCLA performance in conjunction with a 13-element germanium detector, and a quantitative analysis of the signal-to-noise improvement of BCLAs are presented. The performance of BCLAs are compared with filters and slits.

Cost-Effectiveness between Double and Single Fecal Immunochemical Test(s) in a Mass Colorectal Cancer Screening.

PubMed

Cai, Shan-Rong; Zhu, Hong-Hong; Huang, Yan-Qin; Li, Qi-Long; Ma, Xin-Yuan; Zhang, Su-Zhan; Zheng, Shu

2016-01-01

This study investigated the cost-effectiveness between double and single Fecal Immunochemical Test(s) (FIT) in a mass CRC screening. A two-stage sequential screening was conducted. FIT was used as a primary screening test and recommended twice by an interval of one week at the first screening stage. We defined the first-time FIT as FIT1 and the second-time FIT as FIT2. If either FIT1 or FIT2 was positive (+), then a colonoscopy was recommended at the second stage. Costs were recorded and analyzed. A total of 24,419 participants completed either FIT1 or FIT2. The detection rate of advanced neoplasm was 19.2% among both FIT1+ and FIT2+, especially high among men with age ≥55 (27.4%). About 15.4% CRC, 18.9% advanced neoplasm, and 29.9% adenoma missed by FIT1 were detected by FIT2 alone. Average cost was $2,935 for double FITs and $2,121 for FIT1 to detect each CRC and $901 for double FITs and $680 for FIT1 to detect each advanced neoplasm. Double FITs are overall more cost-effective, having significantly higher positive and detection rates with an acceptable higher cost, than single FIT. Double FITs should be encouraged for the first screening in a mass CRC screening, especially in economically and medically underserved populations/areas/countries.

Local concurrent error detection and correction in data structures using virtual backpointers

NASA Technical Reports Server (NTRS)

Li, C. C.; Chen, P. P.; Fuchs, W. K.

1987-01-01

A new technique, based on virtual backpointers, for local concurrent error detection and correction in linked data structures is presented. Two new data structures, the Virtual Double Linked List, and the B-tree with Virtual Backpointers, are described. For these structures, double errors can be detected in 0(1) time and errors detected during forward moves can be corrected in 0(1) time. The application of a concurrent auditor process to data structure error detection and correction is analyzed, and an implementation is described, to determine the effect on mean time to failure of a multi-user shared database system. The implementation utilizes a Sequent shared memory multiprocessor system operating on a shared databased of Virtual Double Linked Lists.

Local concurrent error detection and correction in data structures using virtual backpointers

NASA Technical Reports Server (NTRS)

Li, Chung-Chi Jim; Chen, Paul Peichuan; Fuchs, W. Kent

1989-01-01

A new technique, based on virtual backpointers, for local concurrent error detection and correction in linked data strutures is presented. Two new data structures, the Virtual Double Linked List, and the B-tree with Virtual Backpointers, are described. For these structures, double errors can be detected in 0(1) time and errors detected during forward moves can be corrected in 0(1) time. The application of a concurrent auditor process to data structure error detection and correction is analyzed, and an implementation is described, to determine the effect on mean time to failure of a multi-user shared database system. The implementation utilizes a Sequent shared memory multiprocessor system operating on a shared database of Virtual Double Linked Lists.

40 CFR 270.21 - Specific part B information requirements for landfills.

Code of Federal Regulations, 2010 CFR

2010-07-01

... surface water at any future time; (ii) The double liner and leak (leachate) detection, collection, and... exemption from the requirements for double liners and a leak detection, collection, and removal system or... information; (iii) If the leak detection system is located in a saturated zone, submit detailed plans and an...

Enzyme-free detection and quantification of double-stranded nucleic acids.

PubMed

Feuillie, Cécile; Merheb, Maxime Mohamad; Gillet, Benjamin; Montagnac, Gilles; Hänni, Catherine; Daniel, Isabelle

2012-08-01

We have developed a fully enzyme-free SERRS hybridization assay for specific detection of double-stranded DNA sequences. Although all DNA detection methods ranging from PCR to high-throughput sequencing rely on enzymes, this method is unique for being totally non-enzymatic. The efficiency of enzymatic processes is affected by alterations, modifications, and/or quality of DNA. For instance, a limitation of most DNA polymerases is their inability to process DNA damaged by blocking lesions. As a result, enzymatic amplification and sequencing of degraded DNA often fail. In this study we succeeded in detecting and quantifying, within a mixture, relative amounts of closely related double-stranded DNA sequences from Rupicapra rupicapra (chamois) and Capra hircus (goat). The non-enzymatic SERRS assay presented here is the corner stone of a promising approach to overcome the failure of DNA polymerase when DNA is too degraded or when the concentration of polymerase inhibitors is too high. It is the first time double-stranded DNA has been detected with a truly non-enzymatic SERRS-based method. This non-enzymatic, inexpensive, rapid assay is therefore a breakthrough in nucleic acid detection.

Retrocausation acting in the single-electron double-slit interference experiment

NASA Astrophysics Data System (ADS)

Hokkyo, Noboru

The single electron double-slit interference experiment is given a time-symmetric interpretation and visualization in terms of the intermediate amplitude of transition between the particle source and the detection point. It is seen that the retarded (causal) amplitude of the electron wave expanding from the source shows an advanced (retrocausal) bifurcation and merging in passing through the double-slit and converges towards the detection point as if guided by the advanced (retrocausal) wave from the detected electron. An experiment is proposed to confirm the causation-retrocausation symmetry of the electron behavior by observing the insensitivity of the interference pattern to non-magnetic obstacles placed in the shadows of the retarded and advanced waves appearing on the rear and front sides of the double-slit.

Prospective study aiming to compare 2D mammography and tomosynthesis + synthesized mammography in terms of cancer detection and recall. From double reading of 2D mammography to single reading of tomosynthesis.

PubMed

Romero Martín, Sara; Raya Povedano, Jose Luis; Cara García, María; Santos Romero, Ana Luz; Pedrosa Garriguet, Margarita; Álvarez Benito, Marina

2018-06-01

To evaluate tomosynthesis compared with 2D-mammography in cancer detection and recalls in a screening-programme, and assess performing synthesized instead of 2D, and compare double reading of 2D with single reading of tomosynthesis. Women (age 50-69 years) participating in the screening-programme were included. 2D-mammography and tomosynthesis were performed. There were four reading models: 2D-mammography (first); 2D-mammography (second); tomosynthesis + synthesized (third); tomosynthesis + synthesized + 2D (fourth reading). Paired double reading of 2D (first+second) and tomosynthesis (third+fourth) were analysed. In 16,067 participants, there were 98 cancers and 1,196 recalls. Comparing double reading of 2D with single reading of tomosynthesis, there was an increase of 12.6 % in cancer detection with the third reading (p= 0.043) and 6.9 % with the fourth reading (p=0.210), and a decrease in recalls of 40.5 % (p<0.001) and 44.4 % (p<0.001), respectively. With double reading of both techniques, there was an increase in cancer detection of 17.4 % (p = 0.004) and a decrease in recalls of 12.5 % (p = 0.001) with tomosynthesis. Single reading of tomosynthesis plus synthesized increased cancer detection and decreased recalls compared with double reading 2D. 2D did not improve results when added to tomosynthesis. • Tomosynthesis increases cancer detection and decreases recall rates versus 2D mammography. • Synthesized-mammography avoids performing 2D, showing higher cancer detection. • Single reading of tomosynthesis + synthesized is feasible as a new practice.

New double-byte error-correcting codes for memory systems

NASA Technical Reports Server (NTRS)

Feng, Gui-Liang; Wu, Xinen; Rao, T. R. N.

1996-01-01

Error-correcting or error-detecting codes have been used in the computer industry to increase reliability, reduce service costs, and maintain data integrity. The single-byte error-correcting and double-byte error-detecting (SbEC-DbED) codes have been successfully used in computer memory subsystems. There are many methods to construct double-byte error-correcting (DBEC) codes. In the present paper we construct a class of double-byte error-correcting codes, which are more efficient than those known to be optimum, and a decoding procedure for our codes is also considered.

DNA origami compliant nanostructures with tunable mechanical properties.

PubMed

Zhou, Lifeng; Marras, Alexander E; Su, Hai-Jun; Castro, Carlos E

2014-01-28

DNA origami enables fabrication of precise nanostructures by programming the self-assembly of DNA. While this approach has been used to make a variety of complex 2D and 3D objects, the mechanical functionality of these structures is limited due to their rigid nature. We explore the fabrication of deformable, or compliant, objects to establish a framework for mechanically functional nanostructures. This compliant design approach is used in macroscopic engineering to make devices including sensors, actuators, and robots. We build compliant nanostructures by utilizing the entropic elasticity of single-stranded DNA (ssDNA) to locally bend bundles of double-stranded DNA into bent geometries whose curvature and mechanical properties can be tuned by controlling the length of ssDNA strands. We demonstrate an ability to achieve a wide range of geometries by adjusting a few strands in the nanostructure design. We further developed a mechanical model to predict both geometry and mechanical properties of our compliant nanostructures that agrees well with experiments. Our results provide a basis for the design of mechanically functional DNA origami devices and materials.

Channeling, Volume Reection and Gamma Emission Using 14GeV Electrons in Bent Silicon Crystals

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

Benson, Brandon

2015-08-14

High energy electrons can be deflected with very tight bending radius using a bent silicon crystal. This produces gamma radiation. As these crystals can be thin, a series of bent silicon crystals with alternating direction has the potential to produce coherent gamma radiation with reasonable energy of the driving electron beam. Such an electron crystal undulator offers the prospect for higher energy radiation at lower cost than current methods. Permanent magnetic undulators like LCLS at SLAC National Accelerator Laboratory are expensive and very large (about 100 m in case of the LCLS undulator). Silicon crystals are inexpensive and compact whenmore » compared to the large magnetic undulators. Additionally, such a high energy coherent light source could be used for probing through materials currently impenetrable by x-rays. In this work we present the experimental data and analysis of experiment T523 conducted at SLAC National Accelerator Laboratory. We collected the spectrum of gamma ray emission from 14 GeV electrons on a bent silicon crystal counting single photons. We also investigated the dynamics of electron motion in the crystal i.e. processes of channeling and volume reflection at 14 GeV, extending and building off previous work. Our single photon spectrum for the amorphous crystal orientation is consistent with bremsstrahlung radiation and the volume reflection crystal orientation shows a trend consistent with synchrotron radiation at a critical energy of 740 MeV. We observe that in these two cases the data are consistent, but we make no further claims because of statistical limitations. We also extended the known energy range of electron crystal dechanneling length and channeling efficiency to 14 GeV.« less

General method for eliminating wave reflection in 2D photonic crystal waveguides by introducing extra scatterers based on interference cancellation of waves

NASA Astrophysics Data System (ADS)

Huang, Hao; Ouyang, Zhengbiao

2018-01-01

We propose a general method for eliminating the reflection of waves in 2 dimensional photonic crystal waveguides (2D-PCWs), a kind of 2D material, by introducing extra scatterers inside the 2D-PCWs. The intrinsic reflection in 2D-PCWs is compensated by the backward-scattered waves from these scatterers, so that the overall reflection is greatly reduced and the insertion loss is improved accordingly. We first present the basic theory for the compensation method. Then, as a demonstration, we give four examples of extremely-low-reflection and high-transmission 90°bent 2D-PCWs created according to the method proposed. In the four examples, it is demonstrated by plane-wave expansion method and finite-difference time-domain method that the 90°bent 2D-PCWs can have high transmission ratio greater than 90% in a wide range of operating frequency, and the highest transmission ratio can be greater than 99.95% with a return loss higher than 43 dB, better than that in other typical 90°bent 2D-PCWs. With our method, the bent 2D-PCWs can be optimized to obtain high transmission ratio at different operating wavelengths. As a further application of this method, a waveguide-based optical bridge for light crossing is presented, showing an optimum return loss of 46.85 dB, transmission ratio of 99.95%, and isolation rates greater than 41.77 dB. The method proposed provides also a useful way for improving conventional waveguides made of cables, fibers, or metal walls in the optical, infrared, terahertz, and microwave bands.

K-shell spectroscopy of silicon ions as diagnostic for high electric fields

NASA Astrophysics Data System (ADS)

Loetzsch, R.; Jäckel, O.; Höfer, S.; Kämpfer, T.; Polz, J.; Uschmann, I.; Kaluza, M. C.; Förster, E.; Stambulchik, E.; Kroupp, E.; Maron, Y.

2012-11-01

We developed a detection scheme, capable of measuring X-ray line shape of tracer ions in μm thick layers at the rear side of a target foil irradiated by ultra intense laser pulses. We performed simulations of the effect of strong electric fields on the K-shell emission of silicon and developed a spectrometer dedicated to record this emission. The combination of a cylindrically bent crystal in von Hámos geometry and a CCD camera with its single photon counting capability allows for a high dynamic range of the instrument and background free spectra. This approach will be used in future experiments to study electric fields of the order of TV/m at high density plasmas close to solid density.

Benefits of the quality assured double and arbitration reading of mammograms in the early diagnosis of breast cancer in symptomatic women.

PubMed

Waldmann, Annika; Kapsimalakou, Smaragda; Katalinic, Alexander; Grande-Nagel, Isabell; Stoeckelhuber, Beate M; Fischer, Dorothea; Barkhausen, Joerg; Vogt, Florian M

2012-05-01

To address the benefits of double and arbitration reading regarding tumour detection rates, percentage of in situ tumours, and number (of patients) needed to send for expert reading (number needed to treat; NNT) for one additional tumour finding. QuaMaDi is a quality assured breast cancer diagnosis programme; with two-view mammography (craniocaudal, mediolateral oblique) and, in case of breast density ACR 3 or 4, routine ultrasound imaging; and with independent double reading of all images. A consecutive sample of symptomatic women, i.e. women at risk for breast cancer, women aged 70 and above, and/or women with preceding BI-RADS III findings, was analysed. 28,558 mammograms were performed (mean age of women: 57.3 [standard deviation: 12.3] years). Discordant findings were present in 3,837 double readings and were sent for arbitration reading. After histopathological assessment, 52 carcinomas were found (thereof 32% in situ). These carcinomas accounted for 1.8 tumours per 1,000 examinations in the total cohort and increased the tumour detection rate up to 16.4/1,000. The NNT in discordant cases was 74. Double and arbitration reading appears to be a useful tool to ensure the quality of early detection of breast lesions in symptomatic women during indication-based, standardised mammography. • Quality assured breast cancer diagnosis is feasible outside organised screening structures. • Double and arbitration reading is beneficial for populations ineligible for screening. • Double and arbitration reading increases the tumour detection rate. • Double and arbitration reading increases the percentage of in situ cancers.

Hepatitis Delta Antigen Requires a Flexible Quasi-Double-Stranded RNA Structure To Bind and Condense Hepatitis Delta Virus RNA in a Ribonucleoprotein Complex

PubMed Central

Griffin, Brittany L.; Chasovskikh, Sergey; Dritschilo, Anatoly

2014-01-01

ABSTRACT The circular genome and antigenome RNAs of hepatitis delta virus (HDV) form characteristic unbranched, quasi-double-stranded RNA secondary structures in which short double-stranded helical segments are interspersed with internal loops and bulges. The ribonucleoprotein complexes (RNPs) formed by these RNAs with the virus-encoded protein hepatitis delta antigen (HDAg) perform essential roles in the viral life cycle, including viral replication and virion formation. Little is understood about the formation and structure of these complexes and how they function in these key processes. Here, the specific RNA features required for HDAg binding and the topology of the complexes formed were investigated. Selective 2′OH acylation analyzed by primer extension (SHAPE) applied to free and HDAg-bound HDV RNAs indicated that the characteristic secondary structure of the RNA is preserved when bound to HDAg. Notably, the analysis indicated that predicted unpaired positions in the RNA remained dynamic in the RNP. Analysis of the in vitro binding activity of RNAs in which internal loops and bulges were mutated and of synthetically designed RNAs demonstrated that the distinctive secondary structure, not the primary RNA sequence, is the major determinant of HDAg RNA binding specificity. Atomic force microscopy analysis of RNPs formed in vitro revealed complexes in which the HDV RNA is substantially condensed by bending or wrapping. Our results support a model in which the internal loops and bulges in HDV RNA contribute flexibility to the quasi-double-stranded structure that allows RNA bending and condensing by HDAg. IMPORTANCE RNA-protein complexes (RNPs) formed by the hepatitis delta virus RNAs and protein, HDAg, perform critical roles in virus replication. Neither the structures of these RNPs nor the RNA features required to form them have been characterized. HDV RNA is unusual in that it forms an unbranched quasi-double-stranded structure in which short base-paired segments are interspersed with internal loops and bulges. We analyzed the role of the HDV RNA sequence and secondary structure in the formation of a minimal RNP and visualized the structure of this RNP using atomic force microscopy. Our results indicate that HDAg does not recognize the primary sequence of the RNA; rather, the principle contribution of unpaired bases in HDV RNA to HDAg binding is to allow flexibility in the unbranched quasi-double-stranded RNA structure. Visualization of RNPs by atomic force microscopy indicated that the RNA is significantly bent or condensed in the complex. PMID:24741096

Aerodynamic characteristics of generalized bent biconic bodies for aero-assisted, orbital-transfer vehicles

NASA Technical Reports Server (NTRS)

Davies, C. B.; Park, C.

1983-01-01

A method was developed to generate the surface coordinates of body shapes suitable for aeroassisted, orbital-transfer vehicles (AOTVs) by extending bent biconic geometries. Lift, drag, and longitudinal moments were calculated for the bodies using Newtonian flow theory. These techniques were applied to symmetric and asymmetric aerobraking vehicles, and to an aeromaneuvering vehicle with high L/D. Results for aerobraking applications indicate that a 70 deg, fore half cone angle with a spherically blunted nose, rounded edges, and a slight asymmetry would be appropriate. Moreover, results show that an aeromaneuvering vehicle with L/D 2.0, and with sufficient stability, is feasible.

High resolution x-ray and gamma ray imaging using diffraction lenses with mechanically bent crystals

DOEpatents

Smither, Robert K [Hinsdale, IL

2008-12-23

A method for high spatial resolution imaging of a plurality of sources of x-ray and gamma-ray radiation is provided. High quality mechanically bent diffracting crystals of 0.1 mm radial width are used for focusing the radiation and directing the radiation to an array of detectors which is used for analyzing their addition to collect data as to the location of the source of radiation. A computer is used for converting the data to an image. The invention also provides for the use of a multi-component high resolution detector array and for narrow source and detector apertures.

Standing Helicon Wave Induced by a Rapidly Bent Magnetic Field in Plasmas.

PubMed

Takahashi, Kazunori; Takayama, Sho; Komuro, Atsushi; Ando, Akira

2016-04-01

An electron energy probability function and a rf magnetic field are measured in a rf hydrogen helicon source, where axial and transverse static magnetic fields are applied to the source by solenoids and to the diffusion chamber by filter magnets, respectively. It is demonstrated that the helicon wave is reflected by the rapidly bent magnetic field and the resultant standing wave heats the electrons between the source and the magnetic filter, while the electron cooling effect by the magnetic filter is maintained. It is interpreted that the standing wave is generated by the presence of a spatially localized change of a refractive index.

Standing Helicon Wave Induced by a Rapidly Bent Magnetic Field in Plasmas

NASA Astrophysics Data System (ADS)

Takahashi, Kazunori; Takayama, Sho; Komuro, Atsushi; Ando, Akira

2016-04-01

An electron energy probability function and a rf magnetic field are measured in a rf hydrogen helicon source, where axial and transverse static magnetic fields are applied to the source by solenoids and to the diffusion chamber by filter magnets, respectively. It is demonstrated that the helicon wave is reflected by the rapidly bent magnetic field and the resultant standing wave heats the electrons between the source and the magnetic filter, while the electron cooling effect by the magnetic filter is maintained. It is interpreted that the standing wave is generated by the presence of a spatially localized change of a refractive index.

Hot metal gas forming of titanium grade 2 bent tubes

NASA Astrophysics Data System (ADS)

Paul, Alexander; Werner, Markus; Trân, Ricardo; Landgrebe, Dirk

2017-10-01

Within the framework of investigations, an exhaust gas component made of Titanium Grade 2 was produced by means of Hot Metal Gas Forming (HMGF) at the Fraunhofer IWU in Chemnitz, Germany. The semi-finished products were two-fold bent, thermal joined, calibrated and pre-formed tubes. So far, a three-stage internal high-pressure forming process at room temperature plus two necessary intermediate heat treatments were used to produce the component. Due to its complexity as well as the limited forming ability of Titanium Grade 2 at room temperature an one step Hot Metal Gas Forming was developed to replace the former procedure.

Design of bent waveguide semiconductor lasers using nonlinear equivalent chirp

NASA Astrophysics Data System (ADS)

Li, Lianyan; Shi, Yuechun; Zhang, Yunshan; Chen, Xiangfei

2018-01-01

Reconstruction equivalent chirp (REC) technique is widely used in the design and fabrication of semiconductor laser arrays and tunable lasers with low cost and high wavelength accuracy. Bent waveguide is a promising method to suppress the zeroth order resonance, which is an intrinsic problem in REC technique. However, it may introduce basic grating chirp and deteriorate the single longitudinal mode (SLM) property of the laser. A nonlinear equivalent chirp pattern is proposed in this paper to compensate the grating chirp and improve the SLM property. It will benefit the realization of low-cost Distributed feedback (DFB) semiconductor laser arrays with accurate lasing wavelength.

The kinetic friction of ZnO nanowires on amorphous SiO2 and SiN substrates

NASA Astrophysics Data System (ADS)

Roy, Aditi; Xie, Hongtao; Wang, Shiliang; Huang, Han

2016-12-01

ZnO nanowires were bent on amorphous SiO2 and SiN substrates in an ambient atmosphere using optical nanomanipulation. The kinetic friction between the nanowires and substrate was determined from the bent shape of the nanowires. The kinetic friction force per unit area, i.e. frictional shear stress, for the ZnO/SiO2 and ZnO/SiN nanowire/substrate systems being measured were 1.05 ± 0.28 and 2.08 ± 0.33 MPa, respectively. The surface roughness and the Hamaker constant of SiO2 and SiN substrates had significant effect on the frictional stresses.

Change in single cystathionine β-synthase domain-containing protein from a bent to flat conformation upon adenosine monophosphate binding.

PubMed

Jeong, Byung-Cheon; Park, Si Hoon; Yoo, Kyoung Shin; Shin, Jeong Sheop; Song, Hyun Kyu

2013-07-01

Cystathionine β-synthase (CBS) domains are small intracellular modules that can act as binding domains for adenosine derivatives, and they may regulate the activity of associated enzymes or other functional domains. Among these, the single CBS domain-containing proteins, CBSXs, from Arabidopsis thaliana, have recently been identified as redox regulators of the thioredoxin system. Here, the crystal structure of CBSX2 in complex with adenosine monophosphate (AMP) is reported at 2.2Å resolution. The structure of dimeric CBSX2 with bound-AMP is shown to be approximately flat, which is in stark contrast to the bent form of apo-CBSXs. This conformational change in quaternary structure is triggered by a local structural change of the unique α5 helix, and by moving each loop P into an open conformation to accommodate incoming ligands. Furthermore, subtle rearrangement of the dimer interface triggers movement of all subunits, and consequently, the bent structure of the CBSX2 dimer becomes a flat structure. This reshaping of the structure upon complex formation with adenosine-containing ligand provides evidence that ligand-induced conformational reorganization of antiparallel CBS domains is an important regulatory mechanism. Copyright © 2013 Elsevier Inc. All rights reserved.

Biasing left-right particle distribution via sideways bending of the upper body

NASA Astrophysics Data System (ADS)

Bernate, Jorge A.; Lin, Eleanor; Fahrig, Rebecca; Milla, Carlos; Iaccarino, Gianluca; Shaqfeh, Eric S. G.

2014-11-01

The ability to target therapeutic aerosols to specific regions of the lungs would result in more effective treatment of localized pulmonary diseases and may also prove beneficial in systemic delivery via the airways. Previous computational and experimental studies have shown that large particles disproportionately enter the left lung. The observed uneven distribution occurs because the trachea bends to the right just before the first bifurcation, causing particles with sufficient inertia to enter the left main bronchus. Via CT imaging, we have shown that it is possible to modify the normal configuration of the trachea by bending sideways. Bending to the right and left results in configurations in which the trachea monotonically and smoothly bends to the first bifurcation. In the left-bent configuration, inertial particles will tend to accumulate towards the right side of the trachea and enter the right main bronchus, and conversely for the right-bent configuration. In this talk, we will present our results of Large-Eddy simulations and particle tracking showing regional deposition and ventilation as a function of the Reynolds and Stokes numbers for realistic models of the upright and bent configurations of an adult human subject.

A patient with mandibular deviation and 3 mandibular incisors treated with asymmetrically bent improved superelastic nickel-titanium alloy wires.

PubMed

Ikeda, Yuhei; Kokai, Satoshi; Ono, Takashi

2018-01-01

Skeletal and dental discrepancies cause asymmetric malocclusions in orthodontic patients. It is difficult to achieve adequate functional occlusion and guidance in patients with congenital absence of a mandibular incisor due to the tooth-size discrepancy. Here, we describe the orthodontic treatment of a 22-year-old woman with an asymmetric Angle Class II malocclusion, mandibular deviation to the left, and 3 mandibular incisors. The anterior teeth and maxillary canines were crowded. We used an improved superelastic nickel-titanium alloy wire (Tomy International, Tokyo, Japan) to compensate for the asymmetric mandibular arch and an asymmetrically bent archwire to move the maxillary molars distally. A skeletal anchorage system provided traction for intermaxillary elastics, and extractions were not needed. We alleviated the crowding and created an ideal occlusion with proper overjet, overbite, and anterior guidance with Class I canine and molar relationships. This method of treatment with an asymmetrically bent nickel-titanium alloy wire provided proper Class I occlusion and anterior guidance despite the mandibular deviation to the left and 3 mandibular incisors, without the need for extractions. Copyright © 2017 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

Direct numerical simulation of turbulence in a bent pipe

NASA Astrophysics Data System (ADS)

Schlatter, Philipp; Noorani, Azad

2013-11-01

A series of direct numerical simulations of turbulent flow in a bent pipe is presented. The setup employs periodic (cyclic) boundary conditions in the axial direction, leading to a nominally infinitely long pipe. The discretisation is based on the high-order spectral element method, using the code Nek5000. Four different curvatures, defined as the ratio between pipe radius and coil radius, are considered: κ = 0 (straight), 0.01 (mild curvature), 0.1 and 0.3 (strong curvature), at bulk Reynolds numbers of up to 11700 (corresponding to Reτ = 360 in the straight pipe case). The result show the turbulence-reducing effect of the curvature (similar to rotation), leading close to relaminarisation in the inner side; the outer side, however, remains fully turbulent. Prpoer orthogonal decomposition (POD) is used to extract the dominant modes, in an effort to explain low-frequency switching of sides inside the pipe. A number of additional interesting features are explored, which include sub-straight and sub-laminar drag for specific choices of curvature and Reynolds number: In particular the case with sub-laminar drag is investigated further, and our analysis shows the existence of a spanwise wave in the bent pipe, which in fact leads to lower overall pressure drop.

Measuring the X-ray Resolving Power of Bent Potassium Acid Phthalate Diffraction Crystals

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

Haugh, M. J.; Wu, M.; Jacoby, K. D.

2014-11-01

This report presents the results from measuring the X-ray resolving power of a curved potassium acid phthalate (KAP(001)) spectrometer crystal using two independent methods. It is part of a continuing effort to measure the fundamental diffraction properties of bent crystals that are used to study various characteristics of high temperature plasmas. Bent crystals like KAP(001) do not usually have the same diffraction properties as corresponding flat crystals. Models that do exist to calculate the effect of bending the crystal on the diffraction properties have simplifying assumptions and their accuracy limits have not been adequately determined. The type of crystals thatmore » we measured is being used in a spectrometer on the Z machine at Sandia National Laboratories (SNL) in Albuquerque, NM. The first technique for measuring the crystal resolving power measures the X-ray spectral line width of the characteristic lines from several metal anodes. The second method uses a diode X-ray source and a dual goniometer arrangement to measure the reflectivity curve of the KAP(001) crystal. The width of that curve is inversely proportional to the crystal resolving power. The measurement results are analyzed and discussed.« less

Modular structural elements in the replication origin region of Tetrahymena rDNA.

PubMed Central

Du, C; Sanzgiri, R P; Shaiu, W L; Choi, J K; Hou, Z; Benbow, R M; Dobbs, D L

1995-01-01

Computer analyses of the DNA replication origin region in the amplified rRNA genes of Tetrahymena thermophila identified a potential initiation zone in the 5'NTS [Dobbs, Shaiu and Benbow (1994), Nucleic Acids Res. 22, 2479-2489]. This region consists of a putative DNA unwinding element (DUE) aligned with predicted bent DNA segments, nuclear matrix or scaffold associated region (MAR/SAR) consensus sequences, and other common modular sequence elements previously shown to be clustered in eukaryotic chromosomal origin regions. In this study, two mung bean nuclease-hypersensitive sites in super-coiled plasmid DNA were localized within the major DUE-like element predicted by thermodynamic analyses. Three restriction fragments of the 5'NTS region predicted to contain bent DNA segments exhibited anomalous migration characteristic of bent DNA during electrophoresis on polyacrylamide gels. Restriction fragments containing the 5'NTS region bound Tetrahymena nuclear matrices in an in vitro binding assay, consistent with an association of the replication origin region with the nuclear matrix in vivo. The direct demonstration in a protozoan origin region of elements previously identified in Drosophila, chick and mammalian origin regions suggests that clusters of modular structural elements may be a conserved feature of eukaryotic chromosomal origins of replication. Images PMID:7784181

Molecular dynamics studies of the conformation of sorbitol

PubMed Central

Lerbret, A.; Mason, P.E.; Venable, R.M.; Cesàro, A.; Saboungi, M.-L.; Pastor, R.W.; Brady, J.W.

2009-01-01

Molecular dynamics simulations of a 3 m aqueous solution of D-sorbitol (also called D-glucitol) have been performed at 300 K, as well as at two elevated temperatures to promote conformational transitions. In principle, sorbitol is more flexible than glucose since it does not contain a constraining ring. However, a conformational analysis revealed that the sorbitol chain remains extended in solution, in contrast to the bent conformation found experimentally in the crystalline form. While there are 243 staggered conformations of the backbone possible for this open-chain polyol, only a very limited number were found to be stable in the simulations. Although many conformers were briefly sampled, only eight were significantly populated in the simulation. The carbon backbones of all but two of these eight conformers were completely extended, unlike the bent crystal conformation. These extended conformers were stabilized by a quite persistent intramolecular hydrogen bond between the hydroxyl groups of carbon C-2 and C-4. The conformational populations were found to be in good agreement with the limited available NMR data except for the C-2–C-3 torsion (spanned by the O-2–O-4 hydrogen bond), where the NMR data supports a more bent structure. PMID:19744646

Experimental and Numerical Investigations of Applying Tip-bottomed Tool for Bending Advanced Ultra-high Strength Steel Sheet

NASA Astrophysics Data System (ADS)

Mitsomwang, Pusit; Borrisutthekul, Rattana; Klaiw-awoot, Ken; Pattalung, Aran

2017-09-01

This research was carried out aiming to investigate the application of a tip-bottomed tool for bending an advanced ultra-high strength steel sheet. The V-die bending experiment of a dual phase steel (DP980) sheet which had a thickness of 1.6 mm was executed using a conventional bending and a tip-bottomed punches. Experimental results revealed that the springback of the bent worksheet in the case of the tip-bottomed punch was less than that of the conventional punch case. To further discuss bending characteristics, a finite element (FE) model was developed and used to simulate the bending of the worksheet. From the FE analysis, it was found that the application of the tip-bottomed punch contributed the plastic deformation to occur at the bending region. Consequently, the springback of the worksheet reduced. In addition, the width of the punch tip was found to affect the deformation at the bending region and determined the springback of the bent worksheet. Moreover, the use of the tip-bottomed punch resulted in the apparent increase of the surface hardness of the bent worksheet, compared to the bending with the conventional punch.

Mammography screening using independent double reading with consensus: is there a potential benefit for computer-aided detection?

PubMed

Skaane, Per; Kshirsagar, Ashwini; Hofvind, Solveig; Jahr, Gunnar; Castellino, Ronald A

2012-04-01

Double reading improves the cancer detection rate in mammography screening. Single reading with computer-aided detection (CAD) has been considered to be an alternative to double reading. Little is known about the potential benefit of CAD in breast cancer screening with double reading. To compare prospective independent double reading of screen-film (SFM) and full-field digital (FFDM) mammography in population-based screening with retrospective standalone CAD performance on the baseline mammograms of the screen-detected cancers and subsequent cancers diagnosed during the follow-up period. The study had ethics committee approval. A 5-point rating scale for probability of cancer was used for 23,923 (SFM = 16,983; FFDM = 6940) screening mammograms. Of 208 evaluable cancers, 104 were screen-detected and 104 were subsequent (44 interval and 60 next screening round) cancers. Baseline mammograms of subsequent cancers were retrospectively classified in consensus without information about cancer location, histology, or CAD prompting as normal, non-specific minimal signs, significant minimal signs, and false-negatives. The baseline mammograms of the screen-detected cancers and subsequent cancers were evaluated by CAD. Significant minimal signs and false-negatives were considered 'actionable' and potentially diagnosable if correctly prompted by CAD. CAD correctly marked 94% (98/104) of the baseline mammograms of the screen-detected cancers (SFM = 95% [61/64]; FFDM = 93% [37/40]), including 96% (23/24) of those with discordant interpretations. Considering only those baseline examinations of subsequent cancers prospectively interpreted as normal and retrospectively categorized as 'actionable', CAD input at baseline screening had the potential to increase the cancer detection rate from 0.43% to 0.51% (P = 0.13); and to increase cancer detection by 16% ([104 + 17]/104) and decrease interval cancers by 20% (from 44 to 35). CAD may have the potential to increase cancer detection by up to 16%, and to reduce the number of interval cancers by up to 20% in SFM and FFDM screening programs using independent double reading with consensus review. The influence of true- and false-positive CAD marks on decision-making can, however, only be evaluated in a prospective clinical study.

Action detection by double hierarchical multi-structure space-time statistical matching model

NASA Astrophysics Data System (ADS)

Han, Jing; Zhu, Junwei; Cui, Yiyin; Bai, Lianfa; Yue, Jiang

2018-03-01

Aimed at the complex information in videos and low detection efficiency, an actions detection model based on neighboring Gaussian structure and 3D LARK features is put forward. We exploit a double hierarchical multi-structure space-time statistical matching model (DMSM) in temporal action localization. First, a neighboring Gaussian structure is presented to describe the multi-scale structural relationship. Then, a space-time statistical matching method is proposed to achieve two similarity matrices on both large and small scales, which combines double hierarchical structural constraints in model by both the neighboring Gaussian structure and the 3D LARK local structure. Finally, the double hierarchical similarity is fused and analyzed to detect actions. Besides, the multi-scale composite template extends the model application into multi-view. Experimental results of DMSM on the complex visual tracker benchmark data sets and THUMOS 2014 data sets show the promising performance. Compared with other state-of-the-art algorithm, DMSM achieves superior performances.

Action detection by double hierarchical multi-structure space–time statistical matching model

NASA Astrophysics Data System (ADS)

Han, Jing; Zhu, Junwei; Cui, Yiyin; Bai, Lianfa; Yue, Jiang

2018-06-01

Aimed at the complex information in videos and low detection efficiency, an actions detection model based on neighboring Gaussian structure and 3D LARK features is put forward. We exploit a double hierarchical multi-structure space-time statistical matching model (DMSM) in temporal action localization. First, a neighboring Gaussian structure is presented to describe the multi-scale structural relationship. Then, a space-time statistical matching method is proposed to achieve two similarity matrices on both large and small scales, which combines double hierarchical structural constraints in model by both the neighboring Gaussian structure and the 3D LARK local structure. Finally, the double hierarchical similarity is fused and analyzed to detect actions. Besides, the multi-scale composite template extends the model application into multi-view. Experimental results of DMSM on the complex visual tracker benchmark data sets and THUMOS 2014 data sets show the promising performance. Compared with other state-of-the-art algorithm, DMSM achieves superior performances.

New crystal spectrograph designs and their application to plasma diagnostics (invited)

NASA Astrophysics Data System (ADS)

Förster, E.; Gäbel, K.; Uschmann, I.

1992-10-01

A special crystal monolith was fabricated for absolute measurements of x-ray wavelength. It consists of two flat quartz plates, accurately cut relative to reflecting net planes, with a fixed distance between them. Absolute wavelengths (i.e., without use of reference lines) of L-shell laser produced spectra of Cu, Ge, As, etc. have been measured in the 7.5-8.5 Å with an accuracy of Δλ/λ=10-5. Our Johann type x-ray spectrometer with a cylindrically bent quartz has been used to reveal line coincidences necessary for photopumping processes. In this scheme source-size influences are smaller, therefore, line profiles have been measured at a spectrometer resolution better than 5000. Because of its focusing in the sagittal plane, a von Hámos type x-ray spectrometer has been used to detect the small x-ray emission of subpicosecond laser-produced plasmas (E=2 mJ, t=100 fs). X-ray spectra of Al both Kα, Kβ lines and Heα-resonance line with its satellites. Finally, a multichannel x-ray microscope has been designed and fabricated. It consists of several two-dimensionally bent crystals where each of them images one x-ray line emitted by a laser-produced plasma. The spatial resolution of x-ray line images is about 5 μm, and the width of the spectral ranges is Δλ/λ=10-4 to 10-2. Thus, the spatial distribution of ions radiating in selected x-ray lines have been found being of interest in the study of population inversions.

Local concurrent error detection and correction in data structures using virtual backpointers

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

Li, C.C.J.; Chen, P.P.; Fuchs, W.K.

1989-11-01

A new technique, based on virtual backpointers, is presented in this paper for local concurrent error detection and correction in linked data structures. Two new data structures utilizing virtual backpointers, the Virtual Double-Linked List and the B-Tree and Virtual Backpointers, are described. For these structures, double errors within a fixed-size checking window can be detected in constant time and single errors detected during forward moves can be corrected in constant time.

Double versus single reading of mammograms in a breast cancer screening programme: a cost-consequence analysis.

PubMed

Posso, Margarita C; Puig, Teresa; Quintana, Ma Jesus; Solà-Roca, Judit; Bonfill, Xavier

2016-09-01

To assess the costs and health-related outcomes of double versus single reading of digital mammograms in a breast cancer screening programme. Based on data from 57,157 digital screening mammograms from women aged 50-69 years, we compared costs, false-positive results, positive predictive value and cancer detection rate using four reading strategies: double reading with and without consensus and arbitration, and single reading with first reader only and second reader only. Four highly trained radiologists read the mammograms. Double reading with consensus and arbitration was 15 % (Euro 334,341) more expensive than single reading with first reader only. False-positive results were more frequent at double reading with consensus and arbitration than at single reading with first reader only (4.5 % and 4.2 %, respectively; p < 0.001). The positive predictive value (9.3 % and 9.1 %; p = 0.812) and cancer detection rate were similar for both reading strategies (4.6 and 4.2 per 1000 screens; p = 0.283). Our results suggest that changing to single reading of mammograms could produce savings in breast cancer screening. Single reading could reduce the frequency of false-positive results without changing the cancer detection rate. These results are not conclusive and cannot be generalized to other contexts with less trained radiologists. • Double reading of digital mammograms is more expensive than single reading. • Compared to single reading, double reading yields a higher proportion of false-positive results. • The cancer detection rate was similar for double and single readings. • Single reading may be a cost-effective strategy in breast cancer screening programmes.

The double slit experiment and the time reversed fire alarm

NASA Astrophysics Data System (ADS)

Halabi, Tarek

2011-03-01

When both slits of the double slit experiment are open, closing one paradoxically increases the detection rate at some points on the detection screen. Feynman famously warned that temptation to "understand" such a puzzling feature only draws us into blind alleys. Nevertheless, we gain insight into this feature by drawing an analogy between the double slit experiment and a time reversed fire alarm. Much as closing the slit increases probability of a future detection, ruling out fire drill scenarios, having heard the fire alarm, increases probability of a past fire (using Bayesian inference). Classically, Bayesian inference is associated with computing probabilities of past events. We therefore identify this feature of the double slit experiment with a time reversed thermodynamic arrow. We believe that much of the enigma of quantum mechanics is simply due to some variation of time's arrow.

Probabilistic double guarantee kidnapping detection in SLAM.

PubMed

Tian, Yang; Ma, Shugen

2016-01-01

For determining whether kidnapping has happened and which type of kidnapping it is while a robot performs autonomous tasks in an unknown environment, a double guarantee kidnapping detection (DGKD) method has been proposed. The good performance of DGKD in a relative small environment is shown. However, a limitation of DGKD is found in a large-scale environment by our recent work. In order to increase the adaptability of DGKD in a large-scale environment, an improved method called probabilistic double guarantee kidnapping detection is proposed in this paper to combine probability of features' positions and the robot's posture. Simulation results demonstrate the validity and accuracy of the proposed method.

Molecular and functional characterization of single-box high-mobility group B (HMGB) chromosomal protein from Aedes aegypti.

PubMed

de Abreu da Silva, Isabel Caetano; Vicentino, Amanda Roberta Revoredo; Dos Santos, Renata Coutinho; da Fonseca, Rodrigo Nunes; de Mendonça Amarante, Anderson; Carneiro, Vitor Coutinho; de Amorim Pinto, Marcia; Aguilera, Estefania Anahi; Mohana-Borges, Ronaldo; Bisch, Paulo Mascarello; da Silva-Neto, Mario Alberto Cardoso; Fantappié, Marcelo Rosado

2018-05-30

High-mobility group B (HMGB) proteins have highly conserved, unique DNA-binding domains, HMG boxes, that can bind non-B-type DNA structures, such as bent, kinked and unwound structures, with high affinity. HMGB proteins also promote DNA bending, looping and unwinding. In this study, we determined the role of the Aedes aegypti single HMG-box domain protein AaHMGB; characterized its structure, spatiotemporal expression levels, subcellular localization, and nucleic acid binding activities; and compared these properties with those of its double-HMG-box counterpart protein, AaHMGB1. Via qRT-PCR, we showed that AaHMGB is expressed at much higher levels than AaHMGB1 throughout mosquito development. In situ hybridization results suggested a role for AaHMGB and AaHMGB1 during embryogenesis. Immunolocalization in the midgut revealed that AaHMGB is exclusively nuclear. Circular dichroism and fluorescence spectroscopy analyses showed that AaHMGB exhibits common features of α-helical structures and is more stably folded than AaHMGB1, likely due to the presence of one or two HMG boxes. Using several DNA substrates or single-stranded RNAs as probes, we observed significant differences between AaHMGB and AaHMGB1 in terms of their binding patterns, activity and/or specificity. Importantly, we showed that the phosphorylation of AaHMGB plays a critical role in its DNA-binding activity. Our study provides additional insight into the roles of single- versus double-HMG-box-containing proteins in nucleic acid interactions for better understanding of mosquito development, physiology and homeostasis. Copyright © 2017. Published by Elsevier B.V.

A double-observer approach for estimating detection probability and abundance from point counts

USGS Publications Warehouse

Nichols, J.D.; Hines, J.E.; Sauer, J.R.; Fallon, F.W.; Fallon, J.E.; Heglund, P.J.

2000-01-01

Although point counts are frequently used in ornithological studies, basic assumptions about detection probabilities often are untested. We apply a double-observer approach developed to estimate detection probabilities for aerial surveys (Cook and Jacobson 1979) to avian point counts. At each point count, a designated 'primary' observer indicates to another ('secondary') observer all birds detected. The secondary observer records all detections of the primary observer as well as any birds not detected by the primary observer. Observers alternate primary and secondary roles during the course of the survey. The approach permits estimation of observer-specific detection probabilities and bird abundance. We developed a set of models that incorporate different assumptions about sources of variation (e.g. observer, bird species) in detection probability. Seventeen field trials were conducted, and models were fit to the resulting data using program SURVIV. Single-observer point counts generally miss varying proportions of the birds actually present, and observer and bird species were found to be relevant sources of variation in detection probabilities. Overall detection probabilities (probability of being detected by at least one of the two observers) estimated using the double-observer approach were very high (>0.95), yielding precise estimates of avian abundance. We consider problems with the approach and recommend possible solutions, including restriction of the approach to fixed-radius counts to reduce the effect of variation in the effective radius of detection among various observers and to provide a basis for using spatial sampling to estimate bird abundance on large areas of interest. We believe that most questions meriting the effort required to carry out point counts also merit serious attempts to estimate detection probabilities associated with the counts. The double-observer approach is a method that can be used for this purpose.

Heat exchanger with leak detecting double wall tubes

DOEpatents

Bieberbach, George; Bongaards, Donald J.; Lohmeier, Alfred; Duke, James M.

1981-01-01

A straight shell and tube heat exchanger utilizing double wall tubes and three tubesheets to ensure separation of the primary and secondary fluid and reliable leak detection of a leak in either the primary or the secondary fluids to further ensure that there is no mixing of the two fluids.

Assessment of Gravel Operation Damage to Prehistoric Sites and Recording the Santa Fe Trail within the John Martin Reservoir Project Area, Bent County, Colorado and Evaluation of Old Las Animas (5BN176), a Late Nineteenth Century Town on the Arkansas River, Bent County, Colorado.

DTIC Science & Technology

1987-06-01

an al ii’nment which orients them towards Fort Lyon. Comparing this to the c’iriul 1 plat for Las Animas City ... ,it can be seen that the streets in...rights, franchises and appurtainances thereunto belonging and, also all that certain piece or parcel of land being and situated within the distance of...rim includes clear, ,irpl, and aqua bottle glass; charcoal; bone; a pontil base olive wine "bttle; and a leather belt part (punched). A heavy growth

Orbital Debris Shape Characterization Project Abstract

NASA Technical Reports Server (NTRS)

Pease, Jessie

2016-01-01

I have been working on a project to further our understanding of orbital debris by helping create a new dataset previously too complex to be implemented in past orbital debris propagation models. I am doing this by creating documentation and 3D examples and illustrations of the shape categories. Earlier models assumed all orbital debris to be spherical aluminum fragments. My project will help expand our knowledge of shape populations to 6 categories: Straight Needle/Rod/Cylinder, Bent Needle/Rod/Cylinder, Flat Plate, Bent Plate, Nugget/Parallelepiped/Spheroid, and Flexible. The last category, Flexible, is still up for discussion and may be modified. These categories will be used to characterize fragments in the DebriSat experiment.

X-ray shearing interferometer

DOEpatents

Koch, Jeffrey A [Livermore, CA

2003-07-08

An x-ray interferometer for analyzing high density plasmas and optically opaque materials includes a point-like x-ray source for providing a broadband x-ray source. The x-rays are directed through a target material and then are reflected by a high-quality ellipsoidally-bent imaging crystal to a diffraction grating disposed at 1.times. magnification. A spherically-bent imaging crystal is employed when the x-rays that are incident on the crystal surface are normal to that surface. The diffraction grating produces multiple beams which interfere with one another to produce an interference pattern which contains information about the target. A detector is disposed at the position of the image of the target produced by the interfering beams.

Inhibition of Bacterial Rna Polymerase by Streptolydigin: Stabilization of A Straight-Bridge-Helix Active-Center Conformation

PubMed Central

Tuske, Steven; Sarafianos, Stefan G.; Wang, Xinyue; Hudson, Brian; Sineva, Elena; Mukhopadhyay, Jayanta; Birktoft, Jens J.; Leroy, Olivier; Ismail, Sajida; Clark, Arthur D.; Dharia, Chhaya; Napoli, Andrew; Laptenko, Oleg; Lee, Jookyung; Borukhov, Sergei; Ebright, Richard H.; Arnold, Eddy

2009-01-01

We define the target, mechanism, and structural basis of inhibition of bacterial RNA polymerase (RNAP) by the tetramic-acid antibiotic streptolydigin (Stl). Stl binds to a site adjacent to, but not overlapping, the RNAP active center and stabilizes an RNAP-active-center conformational state with a straight bridge helix. The results provide direct support for the proposals that alternative straight-bridge-helix and bent-bridge-helix RNAP-active-center conformations exist, and that cycling between straight-bridge-helix and bent-bridge-helix RNAP-active-center conformations is required for RNAP function. The results set bounds on models for RNAP function and suggest strategies for design of novel antibacterial agents. PMID:16122422

Interferometric detection of nanoparticles

NASA Astrophysics Data System (ADS)

Hayrapetyan, Karen

Interferometric surfaces enhance light scattering from nanoparticles through constructive interference of partial scattered waves. By placing the nanoparticles on interferometric surfaces tuned to a special surface phase interferometric condition, the particles are detectable in the dilute limit through interferometric image contrast in a heterodyne light scattering configuration, or through diffraction in a homodyne scattering configuration. The interferometric enhancement has applications for imaging and diffractive biosensors. We present a modified model based on Double Interaction (DI) to explore bead-based detection mechanisms using imaging, scanning and diffraction. The application goal of this work is to explore the trade-offs between the sensitivity and throughput among various detection methods. Experimentally we use thermal oxide on silicon to establish and control surface interferometric conditions. Surface-captured gold beads are detected using Molecular Interferometric Imaging (MI2) and Spinning-Disc Interferometry (SDI). Double-resonant enhancement of light scattering leads to high-contrast detection of 100 nm radius gold nanoparticles on an interferometric surface. The double-resonance condition is achieved when resonance (or anti-resonance) from an asymmetric Fabry-Perot substrate coincides with the Mie resonance of the gold nanoparticle. The double-resonance condition is observed experimentally using molecular interferometric imaging (MI2). An invisibility condition is identified for which the gold nanoparticles are optically cloaked by the interferometric surface.

Assessment of mercury exposure and maternal-foetal transfer in Miniopterus schreibersii (Chiroptera: Miniopteridae) from southeastern Iberian Peninsula.

PubMed

Lisón, Fulgencio; Espín, Silvia; Aroca, Bárbara; Calvo, José F; García-Fernández, Antonio J

2017-02-01

Mercury (Hg) is a highly toxic and widely distributed metal that is bioaccumulated in insectivorous mammals and may cause adverse effects on the reproductive system. Bats are considered excellent Hg bioindicators due to their wide distribution, life span, trophic position, metabolic rate and food intake. However, few studies have analysed Hg residues in bats, and to the best of our knowledge, no studies have been made in the Iberian Peninsula. The main aim of this study was to undertake the first ever assessment of Hg exposure in Schreiber's bent-winged bats inhabiting a natural cave in the southeast of Spain. The findings suggest that Schreiber's bent-winged bats in the sampling area are chronically exposed to low levels of Hg. The Hg concentrations found in different tissues (fur, kidney, liver, muscle and brain) were below the threshold levels associated with toxic effects in mammals. Non-gestating females showed Hg concentrations in the brain and muscle that doubled those found in gestating females. This could be due to Hg mobilization from the mother to the foetus in gestating females, although other factors could contribute to explain this result such as variations in hunting areas and the insect-prey consumed and/or different energetic needs and average food consumption during the breeding season. Hg levels were 1.7 times higher, although not significant, in foetus' brains than in the maternal brains, and Hg concentration in foetus' brain was significantly correlated with levels in the corresponding mothers' kidney. These results suggest that there could be an active mother-to-foetus transfer of Hg in bats, which would be of special relevance in a scenario of higher Hg exposure than that found in this study. However, further research is needed to support this view due to the limited number of samples analysed. Given the scarce ecotoxicological data available for bats and their protected status, we encourage further opportunistic studies using carcasses found in the field, the validation of non-destructive samples such as fur and guano for Hg monitoring, and new modelling approaches that will increase the data needed for proper ecological risk assessment in bat populations.

Hollow waveguides for the transmission of quantum cascade laser (QCL) energy for spectroscopic applications

NASA Astrophysics Data System (ADS)

Harrington, James A.; Bledt, Carlos M.; Kriesel, Jason M.

2011-03-01

Spectroscopy in the long-wave infrared (LWIR) wavelength region (8 to 12 μm) is useful for detecting trace chemical compounds, such as those indicative of weapons of mass destruction (WMD). To enable the development of field portable systems for anti-proliferation efforts, current spectroscopy systems need to be made more robust, convenient, and practical (e.g., miniaturized). Hollow glass waveguides have been used with a Quantum Cascade Laser source for the delivery of single-mode laser radiation from 9 to 10 μm. The lowest loss measured for a straight, 484 μm-bore guide was 0.44 dB/m at 10 μm. The smallest 300 μm-bore waveguide transmitted singlemode radiation even while bent to radii less than 30 cm.

GEM detector development for tokamak plasma radiation diagnostics: SXR poloidal tomography

NASA Astrophysics Data System (ADS)

Chernyshova, Maryna; Malinowski, Karol; Ziółkowski, Adam; Kowalska-Strzeciwilk, Ewa; Czarski, Tomasz; Poźniak, Krzysztof T.; Kasprowicz, Grzegorz; Zabołotny, Wojciech; Wojeński, Andrzej; Kolasiński, Piotr; Krawczyk, Rafał D.

2015-09-01

An increased attention to tungsten material is related to a fact that it became a main candidate for the plasma facing material in ITER and future fusion reactor. The proposed work refers to the studies of W influence on the plasma performances by developing new detectors based on Gas Electron Multiplier GEM) technology for tomographic studies of tungsten transport in ITER-oriented tokamaks, e.g. WEST project. It presents current stage of design and developing of cylindrically bent SXR GEM detector construction for horizontal port implementation. Concept to overcome an influence of constraints on vertical port has been also presented. It is expected that the detecting unit under development, when implemented, will add to the safe operation of tokamak bringing creation of sustainable nuclear fusion reactors a step closer.

Nitride-Based Materials for Flexible MEMS Tactile and Flow Sensors in Robotics

PubMed Central

Abels, Claudio; Mastronardi, Vincenzo Mariano; Guido, Francesco; Dattoma, Tommaso; Qualtieri, Antonio; Megill, William M.; De Vittorio, Massimo; Rizzi, Francesco

2017-01-01

The response to different force load ranges and actuation at low energies is of considerable interest for applications of compliant and flexible devices undergoing large deformations. We present a review of technological platforms based on nitride materials (aluminum nitride and silicon nitride) for the microfabrication of a class of flexible micro-electro-mechanical systems. The approach exploits the material stress differences among the constituent layers of nitride-based (AlN/Mo, SixNy/Si and AlN/polyimide) mechanical elements in order to create microstructures, such as upwardly-bent cantilever beams and bowed circular membranes. Piezoresistive properties of nichrome strain gauges and direct piezoelectric properties of aluminum nitride can be exploited for mechanical strain/stress detection. Applications in flow and tactile sensing for robotics are described. PMID:28489040

Field-Induced Alignment of Polar Bent-Ccore Smectic A Liquid Crystals

NASA Astrophysics Data System (ADS)

Shen, Yongqiang; Goodhew, Lisa; Shao, Renfan; Maclennan, Joseph; Clark, Noel; Rudquist, Per

2014-03-01

The SmAPF phase is a promising phase modulator mode. To use the SmAPF materials for applications, we need to obtain uniform, large-area alignment of the samples. However, bent-core liquid crystals are notoriously difficult to align with conventional surface treatment methods because most of them have no nematic phase. We have developed a powerful, new method using in-plane applied electric fields that allows us to create a perfect bookshelf alignment of orthogonal bent-core smectics. By using an interdigitated, finger-like electrode arrangement on one of the cell surfaces, we can align the materials by applying in-plane electric fields. This stripe geometry, which produces curved field lines, allows for only one smectic layer orientation, normal both to the cell walls and to the finger electrodes. After alignment, the cell can be operated in the conventional way by connecting the finger electrodes together to make one effective electrode, opposing continuous, common electrode on the opposite side of the cell. This alignment method opens up the use of these materials in perfectly aligned cells for both amplitude and phase-only modulation applications. This work was supported by NSF MRSEC Grant No. DMR-0820579, by NSF Grant No. DMR-1008300, and by Swedish Research Council (VR) Grant No. 621-2009-3621.

Nonlinear d10-ML2 Transition-Metal Complexes

PubMed Central

Wolters, Lando P; Bickelhaupt, F Matthias

2013-01-01

We have investigated the molecular geometries of a series of dicoordinated d10-transition-metal complexes ML2 (M=Co−, Rh−, Ir−, Ni, Pd, Pt, Cu+, Ag+, Au+; L=NH3, PH3, CO) using relativistic density functional theory (DFT) at ZORA-BLYP/TZ2P. Not all complexes have the expected linear ligand–metal–ligand (L–M–L) angle: this angle varies from 180° to 128.6° as a function of the metal as well as the ligands. Our main objective is to present a detailed explanation why ML2 complexes can become bent. To this end, we have analyzed the bonding mechanism in ML2 as a function of the L–M–L angle using quantitative Kohn–Sham molecular orbital (MO) theory in combination with an energy decomposition analysis (EDA) scheme. The origin of bent L–M–L structures is π backdonation. In situations of strong π backdonation, smaller angles increase the overlap of the ligand’s acceptor orbital with a higher-energy donor orbital on the metal-ligand fragment, and therefore favor π backdonation, resulting in additional stabilization. The angle of the complexes thus depends on the balance between this additional stabilization and increased steric repulsion that occurs as the complexes are bent. PMID:24551547

Nanodoping: a route for enhancing electro-optic performance of bent core nematic system

NASA Astrophysics Data System (ADS)

Kumar, Pradeep; Debnath, Somen; Rao, Nandiraju V. S.; Sinha, Aloka

2018-03-01

We report the effect of dispersion of barium titanate (BaTiO3) nanoparticles (BNPs) in a four ring bent core nematic (BCN) liquid crystal. Polarizing optical microscopy reveals the presence of a single nematic phase in pure and doped states. Polar switching has been observed in the bent core system and the value of spontaneous polarization (P s) increases with increase in doping concentration of BNPs in BCN. Dielectric study shows a lower frequency mode, which can be ascribed to the formation of cybotactic clusters. These clusters are also responsible for the observed polar switching in pure, as well as, in doped BCNs. Another higher frequency mode, observed only in pure BCN, indicates the rotation of molecules about their long molecular axis. The conductivity of doped samples is also found to decrease as compared to the pure BCN. This reduction helps in the minimization of negative effects caused by free ions in liquid crystal based devices. This study demonstrates that the interaction between BNPs and BCN molecules improves the P s, dielectric behaviour, viscosity and reduces the conductivity of pure BCN. Hence, nanodoping in a BCN is an effective method for the enhancement of electro-optic performances and will lead to the development of faster electro-optic devices.

Detecting RNA/DNA hybridization using double-labeled donor probes with enhanced fluorescence resonance energy transfer signals.

PubMed

Okamura, Yukio; Watanabe, Yuichiro

2006-01-01

Fluorescence resonance energy transfer (FRET) occurs when two fluorophores are in close proximity, and the emission energy of a donor fluorophore is transferred to excite an acceptor fluorophore. Using such fluorescently labeled oligonucleotides as FRET probes, makes possible specific detection of RNA molecules even if similar sequences are present in the environment. A higher ratio of signal to background fluorescence is required for more sensitive probe detection. We found that double-labeled donor probes labeled with BODIPY dye resulted in a remarkable increase in fluorescence intensity compared to single-labeled donor probes used in conventional FRET. Application of this double-labeled donor system can improve a variety of FRET techniques.

Double peak-induced distance error in short-time-Fourier-transform-Brillouin optical time domain reflectometers event detection and the recovery method.

PubMed

Yu, Yifei; Luo, Linqing; Li, Bo; Guo, Linfeng; Yan, Jize; Soga, Kenichi

2015-10-01

The measured distance error caused by double peaks in the BOTDRs (Brillouin optical time domain reflectometers) system is a kind of Brillouin scattering spectrum (BSS) deformation, discussed and simulated for the first time in the paper, to the best of the authors' knowledge. Double peak, as a kind of Brillouin spectrum deformation, is important in the enhancement of spatial resolution, measurement accuracy, and crack detection. Due to the variances of the peak powers of the BSS along the fiber, the measured starting point of a step-shape frequency transition region is shifted and results in distance errors. Zero-padded short-time-Fourier-transform (STFT) can restore the transition-induced double peaks in the asymmetric and deformed BSS, thus offering more accurate and quicker measurements than the conventional Lorentz-fitting method. The recovering method based on the double-peak detection and corresponding BSS deformation can be applied to calculate the real starting point, which can improve the distance accuracy of the STFT-based BOTDR system.

Pre-bent instruments used in single-port laparoscopic surgery versus conventional laparoscopic surgery: comparative study of performance in a dry lab.

PubMed

Miernik, Arkadiusz; Schoenthaler, Martin; Lilienthal, Kerstin; Frankenschmidt, Alexander; Karcz, Wojciech Konrad; Kuesters, Simon

2012-07-01

Different types of single-incision laparoscopic surgery (SILS) have become increasingly popular. Although SILS is technically even more challenging than conventional laparoscopy, published data of first clinical series seem to demonstrate the feasibility of these approaches. Various attempts have been made to overcome restrictions due to loss of triangulation in SILS by specially designed SILS-specific instruments. This study involving novices in a dry lab compared task performances between conventional laparoscopic surgery (CLS) and single-port laparoscopic surgery (SPLS) using newly designed pre-bent instruments. In this study, 90 medical students without previous experience in laparoscopic techniques were randomly assigned to undergo one of three procedures: CLS, SPLS using two pre-bent instruments (SPLS-pp), or SPLS using one pre-bent and one straight laparoscopic instrument (SPLS-ps). In the dry lab, the participants performed four typical laparoscopic tasks of increasing difficulty. Evaluation included performance times or number of completed tasks within a given time frame. All performances were videotaped and evaluated for unsuccessful attempts and unwanted interactions of instruments. Using subjective questionnaires, the participants rated difficulties with two-dimensional vision and coordination of instruments. Task performances were significantly better in the CLS group than in either SPLS group. The SPLS-ps group showed a tendency toward better performances than the SPLS-pp group, but the difference was not significant. Video sequences and participants` questionnaires showed instrument interaction as the major problem in the single-incision surgery groups. Although SILS is feasible, as shown in clinical series published by laparoscopically experienced experts, SILS techniques are demanding due to restrictions that come with the loss of triangulation. These can be compensated only partially by currently available SILS-designed instruments. The future of SILS depends on further improvements in the available equipment or the development of new approaches such as needlescopically assisted or robotically assisted procedures.

Do nonbonded H--H interactions in phenanthrene stabilize it relative to anthracene? A possible resolution to this question and its implications for ligands such as 2,2'-bipyridyl.

PubMed

Hancock, Robert D; Nikolayenko, Igor V

2012-08-23

The problem of whether interactions between the hydrogen atoms at the 1,10-positions in the "cleft" of the "bent" phenanthrene stabilize the latter molecule thermodynamically relative to "linear" anthracene, or whether the higher stability of phenanthrene is due to a more energetically favorable π-system, is considered. DFT calculations at the X3LYP/cc-pVTZ(-f)++ level of the ground state energies (E) of anthracene, phenanthrene, and the set of five benzoquinolines are reported. In the gas phase, "bent" phenanthrene was computed to be thermodynamically more stable than "linear" anthracene by -28.5 kJ mol(-1). This fact was attributed predominantly to the phenomenon of higher aromatic stabilization of the π-system of phenanthrene relative to anthracene, and not to the stabilizing influence of the nonbonding H--H interactions in its cleft. In fact, these interactions in phenanthrene were shown to be destabilizing. Similar calculations for five benzoquinolines (bzq) indicate that ΔE values vary as: 6,7-bzq (linear) ≤ 2,3-bzq (linear) < 5,6-bzq (bent) ≤ 3,4-bzq (bent) < 7,8-bzq (bent, no H--H nonbonding interactions in cleft), supporting the idea that it is a more stable π-system that favors 7,8-bzq over 2,3-bzq and 6,7-bzq, and that the H--H interactions in the clefts of 3,4-bzq and 5,6-bzq are destabilizing. Intramolecular hydrogen bonding in the cleft of 7,8-bzq plays a secondary role in its stabilization relative 6,7-bzq. The question of whether H--H nonbonded interactions between H atoms at the 3 and 3' positions of 2,2'-bipyridyl (bpy) coordinated to metal ions are stabilizing or destabilizing is then considered. The energy of bpy is scanned as a function of N-C-C-N torsion angle (χ) in the gas-phase, and it is found that the trans form is 32.8 kJ mol(-1) more stable than the cis conformer. A relaxed coordinate scan of energy of bpy in aqueous solution as a function of χ is modeled using the PBF approach, and it is found that the trans conformer is still more stable than the cis, but now only by 5.34 kJ mol(-1). The effect that the latter energy has on the thermodynamic stability of complexes of metal ions with bpy in aqueous solution is discussed.

Suite of three protein crystallography beamlines with single superconducting bend magnet as the source.

PubMed

MacDowell, Alastair A; Celestre, Rich S; Howells, Malcolm; McKinney, Wayne; Krupnick, James; Cambie, Daniella; Domning, Edward E; Duarte, Robert M; Kelez, Nicholas; Plate, David W; Cork, Carl W; Earnest, Thomas N; Dickert, Jeffery; Meigs, George; Ralston, Corie; Holton, James M; Alber, Tom; Berger, James M; Agard, David A; Padmore, Howard A

2004-11-01

At the Advanced Light Source, three protein crystallography beamlines have been built that use as a source one of the three 6 T single-pole superconducting bending magnets (superbends) that were recently installed in the ring. The use of such single-pole superconducting bend magnets enables the development of a hard X-ray program on a relatively low-energy 1.9 GeV ring without taking up insertion-device straight sections. The source is of relatively low power but, owing to the small electron beam emittance, it has high brightness. X-ray optics are required to preserve the brightness and to match the illumination requirements for protein crystallography. This was achieved by means of a collimating premirror bent to a plane parabola, a double-crystal monochromator followed by a toroidal mirror that focuses in the horizontal direction with a 2:1 demagnification. This optical arrangement partially balances aberrations from the collimating and toroidal mirrors such that a tight focused spot size is achieved. The optical properties of the beamline are an excellent match to those required by the small protein crystals that are typically measured. The design and performance of these new beamlines are described.

Longitudinal magnet forces?

NASA Astrophysics Data System (ADS)

Graneau, P.

1984-03-01

The Ampere electrodynamics of metallic conductors and experiments supporting it predict that the interaction of a current-carrying wire with its own magnetic field should produce longitudinal mechanical forces in the conductor, existing in addition to the transverse Lorentz forces. The longitudinal forces should stretch the conductor and have been referred to as Ampere tension. In 1964 it was discovered that a current pulse would break a straight copper wire into many fragments without visible melting. A metallurgical examination of the pieces confirmed that the metal parted in the solid state. The same observation has now been made with aluminum wires. In the latest experiments the wire was bent into a semicircle and arc-connected to a capacitor discharge circuit. The arc connections ruled out rupture by Lorentz hoop tension and indicated the longitudinal forces may also arise in circular magnet windings. Explanations of wire fragmentation by thermal shock, longitudinal stress waves, Lorentz pinch-off, bending stresses, and material defects have been considered and found unconvincing. Computed Ampere tensions would be sufficient to fracture hot wires. The Ampere tension would double the hoop tension normally expected in dipole magnets. This should be borne in mind in the design of large dipole magnets contemplated for MHD power generators and railgun accelerators.

Experimental and Theoretical Study of Thermodynamics of the Reaction of Titania and Water at High Temperatures

NASA Technical Reports Server (NTRS)

Nguyen, Quynhgiao N.; Myers, Dwight L.; Jacobson, Nathan S.; Opila, Elizabeth J.

2014-01-01

The transpiration method was used to determine the volatility of titanium dioxide (TiO2) in water vapor-containing environments at temperatures between 1473 and 1673 K. Water contents ranged from 0 to 76 mole % in oxygen or argon carrier gases for 20 to 250 hr exposure times. Results indicate that oxygen is not a key contributor to volatilization and the primary reaction for volatilization in this temperature range is: TiO2(s) + H2O(g) = TiO(OH)2(g). Data were analyzed with both the second and third law methods to extract an enthalpy and entropy of formation. The geometry and vibrational frequencies of TiO(OH)2(g) were computed using B3LYP density functional theory, and the enthalpy of formation was computed using the coupled-cluster singles and doubles method with a perturbative correction for connected triple substitutions [CCSD(T)]. Thermal functions are calculated using both a structure with bent and linear hydroxyl groups. Calculated second and third heats show closer agreement with the linear hydroxyl group, suggesting more experimental and computational spectroscopic and structural work is needed on this system.

The (FHCl)- molecular anion - Structural aspects, global surface, and vibrational eigenspectrum

NASA Technical Reports Server (NTRS)

Klepeis, Neil E.; East, Allan L. L.; Csaszar, Attila G.; Allen, Wesley D.; Lee, Timothy J.; Schwenke, David W.

1993-01-01

State of the art ab initio electronic structure methods have been used to investigate the (FHCl)- molecular anion. It is proposed that the geometric structure and binding energies of the complex are r(e)(H-F) = 0.963 +/- 0.003 A, R(e)(H-Cl) = 1.925 +/- 0.015 A, and D0(HF + Cl(-)) = 21.8 +/- 0.4 kcal/mol. A Morokuma decomposition of the ion-molecular bonding give the following electrostatic, polarization, exchange repulsion, dispersion, and charge-transfer plus higher-order mixing components of the vibrationless complexation energy: -27.3, -5.2, +18.3, -4.5, and -5.0 kcal/mol, respectively. A couples cluster single and doubles global surface is constructed from 208 and 228 energy points for linear and bent configurations, respectively, these being fit to rms errors of only 3.9 and 9.3/cm, respectively, below 8000/cm. Converged J = 0 and J = 1 variational eigenstates of the (FHCl)- surface to near the HF + Cl(-) dissociation threshold are determined. The fundamental vibrational frequencies are found to be nu1 = 247/cm, nu2 = 876/cm, and nu3 = 2884/cm. The complete vibrational eigenspectrum is analyzed.

Radiation properties of two types of luminous textile devices containing plastic optical fibers

NASA Astrophysics Data System (ADS)

Selm, Bärbel; Rothmaier, Markus

2007-05-01

Luminous textiles have the potential to satisfy a need for thin and flexible light diffusers for treatment of intraoral cancerous tissue. Plastic optical fibers (POF) with diameters of 250 microns and smaller are used to make the textiles luminous. Usually light is supplied to the optical fiber at both ends. On the textile surface light emission occurs in a woven structure via damaged straight POFs, whereas the embroidered structure radiates the light out of macroscopically bent POFs. We compared the optical properties of these two types of textile diffusers using red light laser for the embroidery and light emitting diode (LED) for the woven structure as light sources, and found efficiencies for the luminous areas of the two samples of 19 % (woven) and 32 % (embroidery), respectively. It was shown that the efficiency can be greatly improved using an aluminium backing. Additional scattering layers lower the fluence rate by around 30 %. To analyse the homogeneity we took a photo of the illuminated surface using a 3CCD camera and found, for both textiles, a slightly skewed distribution of the dark and bright pixels. The interquartile range of brightness distribution of the embroidery is more than double as the woven structure.

The soft x-ray beamline at Frascati Labs

NASA Astrophysics Data System (ADS)

Cinque, Gianfelice; Burattini, Emilio; Grilli, Antonio; Dabagov, Sultan

2005-08-01

DAΦNE-Light is the Synchrotron Radiation laboratory at the Laboratori Nazionali di Frascati (LNF)1. Three beamlines were commissioned since spring 2003 to exploit parasitically the intense photon emission from DAΦNE, the 0.5 1 GeV storage ring routinely circulating over 1 A of electrons. The soft X-ray beamline utilizes a wiggler source and, by a double-crystal fixed-exit monochromator, it is operational in the distinguishing energy window 1.5 - 4 keV range to be extended from the "water window" toward 6 keV. At present, the research activity is focused on X-ray Absorption Spectroscopy (XAS): precisely, X-ray Absorption Near Edge Spectroscopy (XANES) on the inner electronic levels of light elements and transition metals from Al to Ge and both d- and f-shells of higher Z atoms. Preliminary tests of X-ray imaging have been performed in view of applying different focusing optics, namely policapillary systems in trasmission and/or bent mica diffractor in back-reflection, for X-ray microscopy and spectromicroscopy experiments. The use of polycapillary systems (lenses, halflenses, capillaries) for studying features of radiation transportation by such structures (X-ray channelling, focusing, bending, etc.) has been planned.

Bent Penis

MedlinePlus

... of Privacy Practices Notice of Nondiscrimination Manage Cookies Advertising Mayo Clinic is a not-for-profit organization and proceeds from Web advertising help support our mission. Mayo Clinic does not ...

X-ray spectrometer based on a bent diamond crystal for high repetition rate free-electron laser applications

DOE PAGES

Boesenberg, Ulrike; Samoylova, Liubov; Roth, Thomas; ...

2017-02-03

A precise spectral characterization of every single pulse is required in many x-ray free-electron laser (XFEL) experiments due to the fluctuating spectral content of self-amplified spontaneous emission (SASE) beams. Bent single-crystal spectrometers can provide sufficient spectral resolution to resolve the SASE spikes while also covering the full SASE bandwidth. To better withstand the high heat load induced by the 4.5 MHz repetition rate of pulses at the forthcoming European XFEL facility, a spectrometer based on single-crystal diamond has been developed. Here, we report a direct comparison of the diamond spectrometer with its Si counterpart in experiments performed at the Linacmore » Coherent Light Source.« less

Analysis on vertical directional couplers with long range surface plasmons for multilayer optical routing

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

Alam, B., E-mail: badrul.alam@uniroma1.it; Veroli, A.; Benedetti, A.

2016-08-28

A structure featuring vertical directional coupling of long-range surface plasmon polaritons between strip waveguides at λ = 1.55 μm is investigated with the aim of producing efficient elements that enable optical multilayer routing for 3D photonics. We have introduced a practical computational method to calculate the interaction on the bent part. This method allows us both to assess the importance of the interaction in the bent part and to control it by a suitable choice of the fabrication parameters that helps also to restrain effects due to fabrication issues. The scheme adopted here allows to reduce the insertion losses compared with othermore » planar and multilayer devices.« less

A novel strategy for screening-out raw milk contaminated with Mycobacterium bovis on dairy farms by double-tagging PCR and electrochemical genosensing.

PubMed

Lermo, Anabel; Liébana, Susana; Campoy, Susana; Fabiano, Silvia; García, M Inés; Soutullo, Adriana; Zumárraga, Martín J; Alegret, Salvador; Pividori, M Isabel

2010-06-01

A highly sensitive assay for rapidly screening-out Mycobacterium bovis in contaminated samples was developed based on electrochemical genosensing. The assay consists of specific amplification and double-tagging of the IS6110 fragment, highly related to M. bovis, followed by electrochemical detection of the amplified product. PCR amplification was carried out using a labeled set of primers and resulted in a amplicon tagged at each terminus with both biotin and digoxigenin. Two different electrochemical platforms for the detection of the double-tagged amplicon were evaluated: (i) an avidin biocomposite (Av-GEB) and (ii) a magneto sensor (m-GEC) combined with streptavidin magnetic beads. In both cases, the double- tagged amplicon was immobilized through its biotinylated end and electrochemically detected, using an antiDig-HRP conjugate, through its digoxigenin end. The assay was determined to be highly sensitive, based on the detection of 620 and 10 fmol of PCR amplicon using the Av-GEB and m-GEC strategies, respectively. Moreover, the m-GEC assay showed promising features for the detection of M. bovis on dairy farms by screening for the presence of the bacterium's DNA in milk samples. The obtained results are discussed and compared with respect to those of inter-laboratory PCR assays and tuberculin skin testing.

Limb muscle sound speed estimation by ultrasound computed tomography excluding receivers in bone shadow

NASA Astrophysics Data System (ADS)

Qu, Xiaolei; Azuma, Takashi; Lin, Hongxiang; Takeuchi, Hideki; Itani, Kazunori; Tamano, Satoshi; Takagi, Shu; Sakuma, Ichiro

2017-03-01

Sarcopenia is the degenerative loss of skeletal muscle ability associated with aging. One reason is the increasing of adipose ratio of muscle, which can be estimated by the speed of sound (SOS), since SOSs of muscle and adipose are different (about 7%). For SOS imaging, the conventional bent-ray method iteratively finds ray paths and corrects SOS along them by travel-time. However, the iteration is difficult to converge for soft tissue with bone inside, because of large speed variation. In this study, the bent-ray method is modified to produce SOS images for limb muscle with bone inside. The modified method includes three steps. First, travel-time is picked up by a proposed Akaike Information Criterion (AIC) with energy term (AICE) method. The energy term is employed for detecting and abandoning the transmissive wave through bone (low energy wave). It results in failed reconstruction for bone, but makes iteration convergence and gives correct SOS for skeletal muscle. Second, ray paths are traced using Fermat's principle. Finally, simultaneous algebraic reconstruction technique (SART) is employed to correct SOS along ray paths, but excluding paths with low energy wave which may pass through bone. The simulation evaluation was implemented by k-wave toolbox using a model of upper arm. As the result, SOS of muscle was 1572.0+/-7.3 m/s, closing to 1567.0 m/s in the model. For vivo evaluation, a ring transducer prototype was employed to scan the cross sections of lower arm and leg of a healthy volunteer. And the skeletal muscle SOSs were 1564.0+/-14.8 m/s and 1564.1±18.0 m/s, respectively.

Double-observer line transect surveys with Markov-modulated Poisson process models for animal availability.

PubMed

Borchers, D L; Langrock, R

2015-12-01

We develop maximum likelihood methods for line transect surveys in which animals go undetected at distance zero, either because they are stochastically unavailable while within view or because they are missed when they are available. These incorporate a Markov-modulated Poisson process model for animal availability, allowing more clustered availability events than is possible with Poisson availability models. They include a mark-recapture component arising from the independent-observer survey, leading to more accurate estimation of detection probability given availability. We develop models for situations in which (a) multiple detections of the same individual are possible and (b) some or all of the availability process parameters are estimated from the line transect survey itself, rather than from independent data. We investigate estimator performance by simulation, and compare the multiple-detection estimators with estimators that use only initial detections of individuals, and with a single-observer estimator. Simultaneous estimation of detection function parameters and availability model parameters is shown to be feasible from the line transect survey alone with multiple detections and double-observer data but not with single-observer data. Recording multiple detections of individuals improves estimator precision substantially when estimating the availability model parameters from survey data, and we recommend that these data be gathered. We apply the methods to estimate detection probability from a double-observer survey of North Atlantic minke whales, and find that double-observer data greatly improve estimator precision here too. © 2015 The Authors Biometrics published by Wiley Periodicals, Inc. on behalf of International Biometric Society.

Double Threshold Energy Detection Based Cooperative Spectrum Sensing for Cognitive Radio Networks with QoS Guarantee

NASA Astrophysics Data System (ADS)

Hu, Hang; Yu, Hong; Zhang, Yongzhi

2013-03-01

Cooperative spectrum sensing, which can greatly improve the ability of discovering the spectrum opportunities, is regarded as an enabling mechanism for cognitive radio (CR) networks. In this paper, we employ a double threshold detection method in energy detector to perform spectrum sensing, only the CR users with reliable sensing information are allowed to transmit one bit local decision to the fusion center. Simulation results will show that our proposed double threshold detection method could not only improve the sensing performance but also save the bandwidth of the reporting channel compared with the conventional detection method with one threshold. By weighting the sensing performance and the consumption of system resources in a utility function that is maximized with respect to the number of CR users, it has been shown that the optimal number of CR users is related to the price of these Quality-of-Service (QoS) requirements.

Effectiveness and cost-effectiveness of double reading in digital mammography screening: A systematic review and meta-analysis.

PubMed

Posso, Margarita; Puig, Teresa; Carles, Misericòrdia; Rué, Montserrat; Canelo-Aybar, Carlos; Bonfill, Xavier

2017-11-01

Double reading is the strategy of choice for mammogram interpretation in screening programmes. It remains, however, unknown whether double reading is still the strategy of choice in the context of digital mammography. Our aim was to determine the effectiveness and cost-effectiveness of double reading versus single reading of digital mammograms in screening programmes. We performed a systematic review by searching the PubMed, Embase, and Cochrane Library databases up to April 2017. We used the QUADAS-2 (Quality Assessment of Diagnostic Accuracy Studies) tool and CHEERS (Consolidated Health Economic Evaluation Reporting Standards) checklist to assess the methodological quality of the diagnostic studies and economic evaluations, respectively. A proportion's meta-analysis approach, 95% Confidence Intervals (95% CI) and test of heterogeneity (P values) were used for pooled results. Costs are expressed US$ PPP (United States Dollar purchasing power parities). The PROSPERO ID of this Systematic Review's protocol is CRD42014013804. Of 1473 potentially relevant hits, four high-quality studies were included. The pooled cancer detection rate of double reading was 6.01 per 1000 screens (CI: 4.47‰-7.77‰), and it was 5.65 per 1000 screens (CI: 3.95‰-7.65‰) for single reading (P=0.76). The pooled proportion of false-positives of double reading was 47.03 per 1000 screens (CI: 39.13‰-55.62‰) and it was 40.60 per 1000 screens (CI: 38.58‰-42.67‰) for single reading (P=0.12). One study reported, for double reading, an ICER (Incremental Cost-Effectiveness Ratio) of 16,684 Euros (24,717 US$ PPP; 2015 value) per detected cancer. Single reading+CAD (computer-aided-detection) was cost-effective in Japan. The evidence of benefit for double reading compared to single reading for digital mammography interpretation is scarce. Double reading seems to increase operational costs, have a not significantly higher false-positive rate, and a similar cancer detection rate. Copyright © 2017 Elsevier B.V. All rights reserved.

Triplex in-situ hybridization

DOEpatents

Fresco, Jacques R.; Johnson, Marion D.

2002-01-01

Disclosed are methods for detecting in situ the presence of a target sequence in a substantially double-stranded nucleic acid segment, which comprises: a) contacting in situ under conditions suitable for hybridization a substantially double-stranded nucleic acid segment with a detectable third strand, said third strand being capable of hybridizing to at least a portion of the target sequence to form a triple-stranded structure, if said target sequence is present; and b) detecting whether hybridization between the third strand and the target sequence has occured.

Detecting the Length of Double-stranded DNA with Solid State Nanopores

NASA Astrophysics Data System (ADS)

Li, Jiali; Gershow, Marc; Stein, Derek; Qun, Cai; Brandin, Eric; Wang, Hui; Huang, Albert; Branton, Dan; Golovchenko, Jene

2003-03-01

We report on the use of nanometer scale diameter, solid-state nanopores as single molecule detectors of double stranded DNA molecules. These solid-state nanopores are fabricated in thin membranes of silicon nitride, by ion beam sculpting 1. They produce discrete electronic signals: current blockages, when an electrically biased nanopore is exposed to DNA molecules in aqueous salt solutions. We demonstrate examples of such electronic signals for 3k base pairs (bp) and 10k bp double stranded DNA molecules, which suggest that these molecules are individually translocating through the nanopore during the detection process. The translocating time for the 10k bp double stranded DNA is about 3 times longer than the 3k bp, demonstrating that a solid-state nanopore device can be used to detect the lengths of double stranded DNA molecules. Similarities and differences with signals obtained from single stranded DNA in a biological nanopores are discussed 2. 1. Li, J., Stein, D., McMullan, C., Branton, D. Aziz, M. J. and Golovchenko, J. Ion Beam Sculpting at nanometer length scales. Nature 412, 166-169 (2001). 2. Meller, A., L. Nivon, E. Brandin, Golovchenko, J. & Branton, D. Proc. Natl. Acad. Sci. USA 97, 1079-1084 (2000).

Occurrence of Double Monoclonal Bands on Protein Electrophoresis: An Unusual Finding.

PubMed

Srinivasan, Vishrut K; Bhagat, Priyanka; Bansal, Frainey; Chhabra, Seema

2016-06-01

Various techniques of protein electrophoresis are used for detection of monoclonal proteins/paraproteins in serum and/or urine of patients with monoclonal gammopathies. These are detected as the so-called 'M' bands (monoclonal bands) on serum protein electrophoresis and/or immunofixation electrophoresis. In most cases, a single M-band is detected. However, more than one M-band can be detected in the samples of a minor proportion of patients. This condition is termed as 'double gammopathy' or 'biclonal gammopathy'. A knowledge of such an unusual occurrence is essential for recognition and appropriate interpretation of this entity.

Strain-Tailored Double-Disk Synergy Test Detects Extended-Spectrum Oxacillinases in Pseudomonas aeruginosa▿

PubMed Central

Hocquet, Didier; Dehecq, Barbara; Bertrand, Xavier; Plésiat, Patrick

2011-01-01

The prevalence of class D extended-spectrum oxacillinases (ES-OXAs) in ceftazidime-resistant strains of Pseudomonas aeruginosa is often underestimated by double-disk synergy tests (DDST) using clavulanate. A DDST with a customized distance between a disk of ceftazidime or cefepime and inhibitors (clavulanate and imipenem) detected 14 out of 15 different ES-OXAs. PMID:21450950

Ureaplasma diversum in bull semen in Australia: its detection and potential effects.

PubMed

Hobson, N; Chousalkar, K K; Chenoweth, P J

2013-11-01

The primary objective of this study was to confirm the infection status of Ureaplasma diversum in Australian bulls and to identify morphological changes of sperm from U. diversum-positive bulls. Fresh semen samples were taken from 29 sexually active beef bulls from suspect herds in the Riverina/Upper Murray region. U. diversum was identified using PCR analyses and culture of the organism. Nine of the bulls were PCR-positive for U. diversum but none of these had genital lesions. Sperm from infected bulls showed increased incidence of abnormal tails (bent and coiled), as well as surface abnormalities (i.e. small protuberances or lumps). The results suggest impairment of sperm function and possibly fertility. Further investigations into the potential role of U. diversum as a pathogen for Australian cattle are warranted. © 2013 Australian Veterinary Association.

Ribosomal targets for antibiotic drug discovery

DOEpatents

Blanchard, Scott C.; Feldman, Michael Brian; Wang, Leyi; Doudna Cate, James H.; Pulk, Arto; Altman, Roger B.; Wasserman, Michael R

2016-09-13

The present invention relates to methods to identify molecules that binds in the neomycin binding pocket of a bacterial ribosome using structures of an intact bacterial ribosome that reveal how the ribosome binds tRNA in two functionally distinct states, determined by x-ray crystallography. One state positions tRNA in the peptidyl-tRNA binding site. The second, a fully rotated state, is stabilized by ribosome recycling factor (RRF) and binds tRNA in a highly bent conformation in a hybrid peptidyl/exit (P/E) site. Additionally, the invention relates to various assays, including single-molecule assay for ribosome recycling, and methods to identify compounds that interfere with ribosomal function by detecting newly identified intermediate FRET states using known and novel FRET pairs on the ribosome. The invention also provides vectors and compositions with an N-terminally tagged S13 protein.

Needle tip localization using stylet vibration.

PubMed

Harmat, Adam; Rohling, Robert N; Salcudean, Septimiu E

2006-09-01

Power Doppler ultrasound is used to localize the tip of a needle by detecting physical vibrations. Two types of vibrations are investigated, lateral and axial. The lateral vibrations are created by rotating a stylet, whose tip is slightly bent, inside a stationary cannula while the stylet is completely within the cannula. The minute deflection at the needle tip when rotated causes tissue motion. The axial vibration is induced by extending and retracting a straight stylet inside a stationary cannula. The stylet's tip makes contact with the tissue and causes it to move. The lateral vibration method was found to perform approximately the same under a variety of configurations (e.g., different insertion angles and depths) and better than the axial vibration method. Tissue stiffness affects the performance of the lateral vibration method, but good images can be obtained through proper tuning of the ultrasound machine.

Meta-analysis of Clinical and Radiographic Outcomes After Arthroscopic Single-Row Versus Double-Row Rotator Cuff Repair

PubMed Central

Perser, Karen; Godfrey, David; Bisson, Leslie

2011-01-01

Context: Double-row rotator cuff repair methods have improved biomechanical performance when compared with single-row repairs. Objective: To review clinical outcomes of single-row versus double-row rotator cuff repair with the hypothesis that double-row rotator cuff repair will result in better clinical and radiographic outcomes. Data Sources: Published literature from January 1980 to April 2010. Key terms included rotator cuff, prospective studies, outcomes, and suture techniques. Study Selection: The literature was systematically searched, and 5 level I and II studies were found comparing clinical outcomes of single-row and double-row rotator cuff repair. Coleman methodology scores were calculated for each article. Data Extraction: Meta-analysis was performed, with treatment effect between single row and double row for clinical outcomes and with odds ratios for radiographic results. The sample size necessary to detect a given difference in clinical outcome between the 2 methods was calculated. Results: Three level I studies had Coleman scores of 80, 74, and 81, and two level II studies had scores of 78 and 73. There were 156 patients with single-row repairs and 147 patients with double-row repairs, both with an average follow-up of 23 months (range, 12-40 months). Double-row repairs resulted in a greater treatment effect for each validated outcome measure in 4 studies, but the differences were not clinically or statistically significant (range, 0.4-2.2 points; 95% confidence interval, –0.19, 4.68 points). Double-row repairs had better radiographic results, but the differences were also not statistically significant (P = 0.13). Two studies had adequate power to detect a 10-point difference between repair methods using the Constant score, and 1 study had power to detect a 5-point difference using the UCLA (University of California, Los Angeles) score. Conclusions: Double-row rotator cuff repair does not show a statistically significant improvement in clinical outcome or radiographic healing with short-term follow-up. PMID:23016017

Meta-analysis of Clinical and Radiographic Outcomes After Arthroscopic Single-Row Versus Double-Row Rotator Cuff Repair.

PubMed

Perser, Karen; Godfrey, David; Bisson, Leslie

2011-05-01

Double-row rotator cuff repair methods have improved biomechanical performance when compared with single-row repairs. To review clinical outcomes of single-row versus double-row rotator cuff repair with the hypothesis that double-row rotator cuff repair will result in better clinical and radiographic outcomes. Published literature from January 1980 to April 2010. Key terms included rotator cuff, prospective studies, outcomes, and suture techniques. The literature was systematically searched, and 5 level I and II studies were found comparing clinical outcomes of single-row and double-row rotator cuff repair. Coleman methodology scores were calculated for each article. Meta-analysis was performed, with treatment effect between single row and double row for clinical outcomes and with odds ratios for radiographic results. The sample size necessary to detect a given difference in clinical outcome between the 2 methods was calculated. Three level I studies had Coleman scores of 80, 74, and 81, and two level II studies had scores of 78 and 73. There were 156 patients with single-row repairs and 147 patients with double-row repairs, both with an average follow-up of 23 months (range, 12-40 months). Double-row repairs resulted in a greater treatment effect for each validated outcome measure in 4 studies, but the differences were not clinically or statistically significant (range, 0.4-2.2 points; 95% confidence interval, -0.19, 4.68 points). Double-row repairs had better radiographic results, but the differences were also not statistically significant (P = 0.13). Two studies had adequate power to detect a 10-point difference between repair methods using the Constant score, and 1 study had power to detect a 5-point difference using the UCLA (University of California, Los Angeles) score. Double-row rotator cuff repair does not show a statistically significant improvement in clinical outcome or radiographic healing with short-term follow-up.

Reliability and performance of innovative surgical double-glove hole puncture indication systems.

PubMed

Edlich, Richard F; Wind, Tyler C; Heather, Cynthia L; Thacker, John G

2003-01-01

During operative procedures, operating room personnel wear sterile surgical gloves designed to protect them and their patients against transmissible infections. The Food and Drug Administration (FDA) has set compliance policy guides for manufacturers of gloves. The FDA allows surgeons' gloves whose leakage defect rates do not exceed 1.5 acceptable quality level (AQL) to be used in operating rooms. The implications of this policy are potentially enormous to operating room personnel and patients. This unacceptable risk to the personnel and patient could be significantly reduced by the use of sterile double surgical gloves. Because double-gloves are also susceptible to needle puncture, a double-glove hole indication system is urgently needed to immediately detect surgical needle glove punctures. This warning would allow surgeons to remove the double-gloves, wash their hands, and then don a sterile set of double-gloves with an indication system. During the last decade, Regent Medical has devised non-latex and latex double-glove hole puncture indication systems. The purpose of this comprehensive study is to detect the accuracy of the non-latex and latex double-glove hole puncture indication systems using five commonly used sterile surgical needles: the taper point surgical needle, tapercut surgical needle, reverse cutting edge surgical needle, taper cardiopoint surgical needle, and spatula surgical needle. After subjecting both the non-latex and latex double-glove hole puncture indication systems to surgical needle puncture in each glove fingertip, these double-glove systems were immersed in a sterile basin of saline, after which the double-gloved hands manipulated surgical instruments. Within two minutes, both the non-latex and latex hole puncture indication systems accurately detected needle punctures in all of the surgical gloves, regardless of the dimensions of the surgical needles. In addition, the size of the color change visualized through the translucent outer glove did not correlate with needle diameter. On the basis of this extensive experimental evaluation, both the non-latex and latex double-glove hole puncture indication systems should be used in all operative procedures by all operating room personnel.

Breast screening using 2D-mammography or integrating digital breast tomosynthesis (3D-mammography) for single-reading or double-reading--evidence to guide future screening strategies.

PubMed

Houssami, Nehmat; Macaskill, Petra; Bernardi, Daniela; Caumo, Francesca; Pellegrini, Marco; Brunelli, Silvia; Tuttobene, Paola; Bricolo, Paola; Fantò, Carmine; Valentini, Marvi; Ciatto, Stefano

2014-07-01

We compared detection measures for breast screening strategies comprising single-reading or double-reading using standard 2D-mammography or 2D/3D-mammography, based on the 'screening with tomosynthesis or standard mammography' (STORM) trial. STORM prospectively examined screen-reading in two sequential phases, 2D-mammography alone and integrated 2D/3D-mammography, in asymptomatic women participating in Trento and Verona (Northern Italy) population-based screening services. Outcomes were ascertained from assessment and/or excision histology or follow-up. For each screen-reading strategy we calculated the number of detected and non-detected (including interval) cancers, cancer detection rates (CDRs), false positive recall (FPR) measures and incremental CDR relative to a comparator strategy. We estimated the false:true positive (FP:TP) ratio and sensitivity of each mammography screening strategy. Paired binary data were compared using McNemar's test. Amongst 7292 screening participants, there were 65 (including six interval) breast cancers; estimated first-year interval cancer rate was 0.82/1000 screens (95% confidence interval (CI): 0.30-1.79/1000). For single-reading, 35 cancers were detected at both 2D and 2D/3D-mammography, 20 cancers were detected only with 2D/3D-mammography compared with none at 2D-mammography alone (p<0.001) and 10 cancers were not detected. For double-reading, 39 cancers were detected at 2D-mammography and 2D/3D-mammography, 20 were detected only with 2D/3D-mammography compared with none detected at 2D-mammography alone (p<0.001) and six cancers were not detected. The incremental CDR attributable to 2D/3D-mammography (versus 2D-mammography) of 2.7/1000 screens (95% CI: 1.6-4.2) was evident for single and for double-reading. Incremental CDR attributable to double-reading (versus single-reading) of 0.55/1000 screens (95% CI: -0.02-1.4) was evident for 2D-mammography and for 2D/3D-mammography. Estimated FP:TP ratios showed that 2D/3D-mammography screening strategies had more favourable FP to TP trade-off and higher sensitivity, applying single-reading or double-reading, relative to 2D-mammography screening. The evidence we report warrants rethinking of breast screening strategies and should be used to inform future evaluations of 2D/3D-mammography that assess whether or not the estimated incremental detection translates into improved screening outcomes such as a reduction in interval cancer rates. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

Flexible nanoporous tunable electrical double layer biosensors for sweat diagnostics.

PubMed

Munje, Rujuta D; Muthukumar, Sriram; Panneer Selvam, Anjan; Prasad, Shalini

2015-09-30

An ultra-sensitive and highly specific electrical double layer (EDL) modulated biosensor, using nanoporous flexible substrates for wearable diagnostics is demonstrated with the detection of the stress biomarker cortisol in synthetic and human sweat. Zinc oxide thin film was used as active region in contact with the liquid i.e. synthetic and human sweat containing the biomolecules. Cortisol detection in sweat was accomplished by measuring and quantifying impedance changes due to modulation of the double layer capacitance within the electrical double layer through the application of a low orthogonally directed alternating current (AC) electric field. The EDL formed at the liquid-semiconductor interface was amplified in the presence of the nanoporous flexible substrate allowing for measuring the changes in the alternating current impedance signal due to the antibody-hormone interactions at diagnostically relevant concentrations. High sensitivity of detection of 1 pg/mL or 2.75 pmol cortisol in synthetic sweat and 1 ng/mL in human sweat is demonstrated with these novel biosensors. Specificity in synthetic sweat was demonstrated using a cytokine IL-1β. Cortisol detection in human sweat was demonstrated over a concentration range from 10-200 ng/mL.

Flexible nanoporous tunable electrical double layer biosensors for sweat diagnostics

NASA Astrophysics Data System (ADS)

Munje, Rujuta D.; Muthukumar, Sriram; Panneer Selvam, Anjan; Prasad, Shalini

2015-09-01

An ultra-sensitive and highly specific electrical double layer (EDL) modulated biosensor, using nanoporous flexible substrates for wearable diagnostics is demonstrated with the detection of the stress biomarker cortisol in synthetic and human sweat. Zinc oxide thin film was used as active region in contact with the liquid i.e. synthetic and human sweat containing the biomolecules. Cortisol detection in sweat was accomplished by measuring and quantifying impedance changes due to modulation of the double layer capacitance within the electrical double layer through the application of a low orthogonally directed alternating current (AC) electric field. The EDL formed at the liquid-semiconductor interface was amplified in the presence of the nanoporous flexible substrate allowing for measuring the changes in the alternating current impedance signal due to the antibody-hormone interactions at diagnostically relevant concentrations. High sensitivity of detection of 1 pg/mL or 2.75 pmol cortisol in synthetic sweat and 1 ng/mL in human sweat is demonstrated with these novel biosensors. Specificity in synthetic sweat was demonstrated using a cytokine IL-1β. Cortisol detection in human sweat was demonstrated over a concentration range from 10-200 ng/mL.

Wenchuan Event Detection And Localization Using Waveform Correlation Coupled With Double Difference

NASA Astrophysics Data System (ADS)

Slinkard, M.; Heck, S.; Schaff, D. P.; Young, C. J.; Richards, P. G.

2014-12-01

The well-studied Wenchuan aftershock sequence triggered by the May 12, 2008, Ms 8.0, mainshock offers an ideal test case for evaluating the effectiveness of using waveform correlation coupled with double difference relocation to detect and locate events in a large aftershock sequence. We use Sandia's SeisCorr detector to process 3 months of data recorded by permanent IRIS and temporary ASCENT stations using templates from events listed in a global catalog to find similar events in the raw data stream. Then we take the detections and relocate them using the double difference method. We explore both the performance that can be expected with using just a small number of stations, and, the benefits of reprocessing a well-studied sequence such as this one using waveform correlation to find even more events. We benchmark our results against previously published results describing relocations of regional catalog data. Before starting this project, we had examples where with just a few stations at far-regional distances, waveform correlation combined with double difference did and impressive job of detection and location events with precision at the few hundred and even tens of meters level.

Controlled manipulation of flexible carbon nanotubes through shape-dependent pushing by atomic force microscopy.

PubMed

Yang, Seung-Cheol; Qian, Xiaoping

2013-09-17

A systematic approach to manipulating flexible carbon nanotubes (CNTs) has been developed on the basis of atomic force microscope (AFM) based pushing. Pushing CNTs enables efficient transport and precise location of individual CNTs. A key issue for pushing CNTs is preventing defective distortion in repetitive bending and unbending deformation. The approach presented here controls lateral movement of an AFM tip to bend CNTs without permanent distortion. The approach investigates possible defects caused by tensile strain of the outer tube under uniform bending and radial distortion by kinking. Using the continuum beam model and experimental bending tests, dependency of maximum bending strain on the length of bent CNTs and radial distortion on bending angles at a bent point have been demonstrated. Individual CNTs are manipulated by limiting the length of bent CNTs and the bending angle. In our approach, multiwalled CNTs with 5-15 nm diameter subjected to bending deformation produce no outer tube breakage under uniform bending and reversible radial deformation with bending angles less than 110°. The lateral tip movement is determined by a simple geometric model that relies on the shape of multiwalled CNTs. The model effectively controls deforming CNT length and bending angle for given CNT shape. Experimental results demonstrate successful manipulation of randomly dispersed CNTs without visual defects. This approach to pushing can be extended to develop a wide range of CNT based nanodevice applications.

Chiral Superstructure Mesophases of Achiral Bent-Shaped Molecules - Hierarchical Chirality Amplification and Physical Properties.

PubMed

Le, Khoa V; Takezoe, Hideo; Araoka, Fumito

2017-07-01

Chiral mesophases in achiral bent-shaped molecules have attracted particular attention since their discovery in the middle 1990s, not only because of their homochirality and polarity, but also due to their unique physical/physicochemical properties. Here, the most intriguing results in the studies of such symmetry-broken states, mainly helical-nanofilament (HNF) and dark-conglomerate (DC) phases, are reviewed. Firstly, basic information on the typical appearance and optical activity in these phases is introduced. In the following section, the formation of mesoscopic chiral superstructures in the HNF and DC phases is discussed in terms of hierarchical chirality. Nanoscale phase segregation in mixture systems and gelation ability in the HNF phase are also described. In addition, some other related chiral phases of bent-shaped molecules are shown. Recent attempts to control such mesoscopic chiral structure and the alignment/confinement of HNFs are also discussed, along with several examples of their fascinating advanced physical properties, i.e. huge enhancement of circular dichroism, electro- and photo-tunable optical activities, chirality-induced nonlinear optics (second-harmonic-generation circular difference and electrogyration effect), enhanced hydrophobicity through the dual-scale surface morphological modulation, and photoconductivity in the HNF/fullerene binary system. Future prospects from basic science and application viewpoints are also indicated in the concluding section. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

THE SPINDLE: AN IRRADIATED DISK AND BENT PROTOSTELLAR JET IN ORION

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

Bally, John; Youngblood, Allison; Ginsburg, Adam, E-mail: John.Bally@colorado.edu, E-mail: Allison.Youngblood@colorado.edu, E-mail: Adam.Ginsburg@colorado.edu

2012-09-10

We present Hubble Space Telescope observations of a bent, pulsed Herbig-Haro jet, HH 1064, emerging from the young star Parenago 2042 embedded in the H II region NGC 1977 located about 30' north of the Orion Nebula. This outflow contains eight bow shocks in the redshifted western lobe and five bow shocks in the blueshifted eastern lobe. Shocks within a few thousand AU of the source star exhibit proper motions of {approx}160 km s{sup -1} but motions decrease with increasing distance. Parenago 2042 is embedded in a proplyd-a photoevaporating protoplanetary disk. A remarkable set of H{alpha} arcs resembling a spindlemore » surround the redshifted (western) jet. The largest arc with a radius of 500 AU may trace the ionized edge of a circumstellar disk inclined by {approx}30 Degree-Sign . The spindle may be the photoionized edge of either a {approx}3 km s{sup -1} FUV-driven wind from the outer disk or a faster MHD-powered flow from an inner disk. The HH 1064 jet appears to be deflected north by photoablation of the south-facing side of a mostly neutral jet beam. V2412 Ori, located 1' west of Parenago 2042 drives a second bent flow, HH 1065. Both HH 1064 and 1065 are surrounded by LL Ori-type bows marking the boundary between the outflow cavity and the surrounding nebula.« less

Investigation of the Electromagnetic Radiation Emitted by Sub-GeV Electrons in a Bent Crystal.

PubMed

Bandiera, L; Bagli, E; Germogli, G; Guidi, V; Mazzolari, A; Backe, H; Lauth, W; Berra, A; Lietti, D; Prest, M; De Salvador, D; Vallazza, E; Tikhomirov, V

2015-07-10

The radiation emitted by 855 MeV electrons via planar channeling and volume reflection in a 30.5-μm-thick bent Si crystal has been investigated at the MAMI (Mainzer Mikrotron) accelerator. The spectral intensity was much more intense than for an equivalent amorphous material, and peaked in the MeV range in the case of channeling radiation. Differently from a straight crystal, also for an incidence angle larger than the Lindhard angle, the spectral intensity remains nearly as high as for channeling. This is due to volume reflection, for which the intensity remains high at a large incidence angle over the whole angular acceptance, which is equal to the bending angle of the crystal. Monte Carlo simulations demonstrated that incoherent scattering significantly influences both the radiation spectrum and intensity, either for channeling or volume reflection. In the latter case, it has been shown that incoherent scattering increases the radiation intensity due to the contribution of volume-captured particles. As a consequence, the experimental spectrum becomes a mixture of channeling and pure volume reflection radiations. These results allow a better understanding of the radiation emitted by electrons subjected to coherent interactions in bent crystals within a still-unexplored energy range, which is relevant for possible applications for innovative and compact x-ray or γ-ray sources.

Methods for Improving the Curvature of Steerable Needles in Biological Tissue

PubMed Central

Adebar, Troy K.; Greer, Joseph D.; Laeseke, Paul F.; Hwang, Gloria L.; Okamura, Allison M.

2016-01-01

Robotic needle steering systems have the potential to improve percutaneous interventions such as radiofrequency ablation of liver tumors, but steering techniques described to date have not achieved sufficiently small radius of curvature in biological tissue to be relevant to this application. In this work, the impact of tip geometry on steerable needle curvature is examined. Finite-element simulations and experiments with bent-tip needles in ex vivo liver tissue demonstrate that selection of tip length and angle can greatly improve curvature, with radius of curvature below 5 cm in liver tissue possible through judicious selection of these parameters. Motivated by the results of this analysis, a new articulated-tip steerable needle is described, in which a distal section is actively switched by a robotic system between a straight tip (resulting in a straight path) and a bent tip (resulting in a curved path). This approach allows the tip length and angle to be increased, while the straight configuration allows the needle tip to still pass through an introducer sheath and rotate inside the body. Validation testing in liver tissue shows that the new articulated-tip steerable needle achieves smaller radius of curvature compared to bent-tip needles described in previous work. Steerable needles with optimized tip parameters, which can generate tight curves in liver tissue, increase the clinical relevance of needle steering to percutaneous interventions. PMID:26441438

Experimental and theoretical characterization of the 2(2)A'-1(2)A' transition of BeOH/D.

PubMed

Mascaritolo, Kyle J; Merritt, Jeremy M; Heaven, Michael C; Jensen, Per

2013-12-19

The hydroxides of Ca, Sr, and Ba are known to be linear molecules, while MgOH is quasilinear. High-level ab initio calculations for BeOH predict a bent equilibrium structure with a bond angle of 140.9°, indicating a significant contribution of covalency to the bonding. However, experimental confirmation of the bent structure is lacking. In the present study, we have used laser excitation techniques to observe the 2(2)A'-1(2)A' transition of BeOH/D in the energy range of 30300-32800 cm(-1). Rotationally resolved spectra were obtained, with sufficient resolution to reveal spin splittings for the electronically excited state. Two-color photoionization was used to determine an ionization energy of 66425(10) cm(-1). Ab initio calculations were used to guide the analysis of the spectroscopic data. Multireference configuration interaction calculations were used to construct potential energy surfaces for the 1(2)A', 2(2)A', and 1(2)A" states. The rovibronic eigenstates supported by these surfaces were determined using the Morse oscillator rigid bender internal dynamics Hamiltonian. The theoretical results were in sufficiently good agreement with the experimental data to permit unambiguous assignment. It was confirmed that the equilibrium geometry of the ground state is bent and that the barrier to linearity lies below the zero-point energies for both BeOH and BeOD.

LCDRS FLOW FROM DOUBLE-LINED LANDFILLS AND SURFACE IMPOUNDMENTS. Project Summary (EPA/600/SR-93/070)

EPA Science Inventory

A study, sponsored by the U.S. Environmental Protection Agency (EPA), on measured flows from leakage detection, collection, and removal systems (LDCRSs) of 28 double-lined landfills and 8 double-lined surface impoundments indicated — all landfills with geomembrane top liners l...

Mathematical Games

ERIC Educational Resources Information Center

Gardner, Martin

1978-01-01

Describes and illustrates the structure of different versions of Mobius bands called prismatic rings or twisted prisms. Different forms are mentioned, such as the one bent into circular shapes and the toroidal polyhedrons. (GA)

Trigger Finger

MedlinePlus

... in a bent position. People whose work or hobbies require repetitive gripping actions are at higher risk ... developing trigger finger include: Repeated gripping. Occupations and hobbies that involve repetitive hand use and prolonged gripping ...

Study of aging and embrittlement of microalloyed steel bars

NASA Astrophysics Data System (ADS)

Campillo, B.; Perez, R.; Martinez, L.

1996-10-01

The aging of hooks, anchors, and other bent reinforcing steel bars in concrete structures are considered in modern international standards. Rebend test procedures have been designed in order to predict the aging embrittlement susceptibility by submerging bent reinforcing bar specimens in boiling water. Subsequently the bars are rebent or straightened in order to determine the loss of ductility or embrittlement of the aged material. The present work considers the influence of carbon, sulfur, and niobium on the performance of reinforcing bars in rebend tests of 300 heats of microalloyed steel bars with a variety of compositions. The microstructural evidence and the statistical results clearly indicate the strong influence of carbon and sulfur on rebend failure, while niobium-rich precipitates contribute to the hardening of the ferrite grains during aging.

Performance of bent-crystal x-ray microscopes for high energy density physics research

DOE PAGES

Schollmeier, Marius S.; Geissel, Matthias; Shores, Jonathon E.; ...

2015-05-29

We present calculations for the field of view (FOV), image fluence, image monochromaticity, spectral acceptance, and image aberrations for spherical crystal microscopes, which are used as self-emission imaging or backlighter systems at large-scale high energy density physics facilities. Our analytic results are benchmarked with ray-tracing calculations as well as with experimental measurements from the 6.151 keV backlighter system at Sandia National Laboratories. Furthermore, the analytic expressions can be used for x-ray source positions anywhere between the Rowland circle and object plane. We discovered that this enables quick optimization of the performance of proposed but untested, bent-crystal microscope systems to findmore » the best compromise between FOV, image fluence, and spatial resolution for a particular application.« less

MovAid- a novel device for advanced rehabilitation monitoring.

PubMed

Gupta, Prashant; Verma, Piyush; Gupta, Rakesh; Verma, Bhawna

2015-08-01

The present article introduces a new device "MovAid" which helps to measure and monitor rehabilitation. It has two main components- "MovAid device" and the "MovAid Smart Phone Application". The device connects wirelessly to the MovAid smart phone application via Bluetooth. It has electronic sensors to measure three important parameters of the patient- Angle of Joint Bent, Lift from the ground and Orientation of the limb. A mono-axis flex sensor to measure the degree of joint bent and a 3-axis accelerometer and gyroscope to measure the orientation of the limb and lift from the ground have been used. MovAid system bridges the gap between caretakers and patients, empowering both in ways never thought of before, by providing detailed and accurate data on every move.

Expected performances of a Laue lens made with bent crystals

NASA Astrophysics Data System (ADS)

Virgilli, Enrico; Valsan, Vineeth; Frontera, Filippo; Caroli, Ezio; Liccardo, Vincenzo; Stephen, John Buchan

2017-10-01

In the context of the Laue project devoted to build a Laue lens prototype for focusing celestial hard x-/soft gamma-rays, a Laue lens made of bent crystal tiles, with 20-m focal length, is simulated. The focusing energy passband is assumed to be 90 to 600 keV. The distortion of the image produced by the lens on the focal plane, due to effects of crystal tile misalignment and radial distortion of the crystal curvature, is investigated. The corresponding effective area of the lens, its point spread function, and sensitivity are calculated and compared with those exhibited by a nominal Laue lens with no misalignment and/or distortion. Such analysis is crucial to estimate the optical properties of a real lens, in which the investigated shortcomings could be present.

Portable standoff Raman system for fast detection of homemade explosives through glass, plastic, and water

NASA Astrophysics Data System (ADS)

Misra, Anupam K.; Sharma, Shiv K.; Acosta, Tayro E.; Porter, John N.; Lucey, Paul G.; Bates, David E.

2012-06-01

The University of Hawaii has been developing portable remote Raman systems capable of detecting chemicals in daylight from a safe standoff distance. We present data on standoff detection of chemicals used in the synthesis of homemade explosives (HME) using a portable standoff Raman system utilizing an 8-inch telescope. Data show that good-quality Raman spectra of various hazardous chemicals such as ammonium nitrate, potassium nitrate, potassium perchlorate, sulfur, nitrobenzene, benzene, acetone, various organic and inorganic chemicals etc. could be easily obtained from remote distances, tested up to 120 meters, with a single-pulse laser excitation and with detection time less than 1 μs. The system uses a frequency-doubled Nd:YAG pulsed laser source (532 nm, 100 mJ/pulse, 15 Hz, pulse width 10 ns) capable of firing a single or double pulse. The double-pulse configuration also allows the system to perform standoff LIBS (Laser-Induced Breakdown Spectroscopy) at 50 m range. In the standoff Raman detection, the doublepulse sequence simply doubles the signal to noise ratio. Significant improvement in the quality of Raman spectra is observed when the standoff detection is made with 1s integration time. The system uses a 50-micron slit and has spectral resolution of 8 cm-1. The HME chemicals could be easily detected through clear and brown glass bottles, PP and HDPE plastic bottles, and also through fluorescent plastic water bottles. Standoff Raman detection of HME chemical from a 10 m distance through non-visible concealed bottles in plastic bubble wrap packaging is demonstrated with 1 s integration time. Possible applications of the standoff Raman system for homeland security and environmental monitoring are discussed.

Visual Double Stars with More Than One WDS Number

NASA Astrophysics Data System (ADS)

Rica, F. M.

2005-04-01

WDS catalog is one of the most important reference for double star observers and we must consider it as something that is ours and so we must maintain it, for example, detecting and communicating errors to the database administrator. In this work the author presents two double stars that had two entries in WDS catalog. The doubles were studied, their nature determined and the errors corrected in WDS.

Fibre optic sensor for the detection of adulterant traces in coconut oil

NASA Astrophysics Data System (ADS)

Sheeba, M.; Rajesh, M.; Vallabhan, C. P. G.; Nampoori, V. P. N.; Radhakrishnan, P.

2005-11-01

The design and development of a fibre optic evanescent wave refractometer for the detection of trace amounts of paraffin oil and palm oil in coconut oil is presented. This sensor is based on a side-polished plastic optical fibre. At the sensing region, the cladding and a small portion of the core are removed and the fibre nicely polished. The sensing region is fabricated in such a manner that it sits perfectly within a bent mould. This bending of the sensing region enhances its sensitivity. The oil mixture of different mix ratios is introduced into the sensing region and we observed a sharp decrease in the output intensity. The observed variation in the intensity is found to be linear and the detection limit is 2% (by volume) paraffin oil/palm oil in coconut oil. The resolution of this refractometric sensor is of the order of 10-3. Since coconut oil is consumed in large volumes as edible oil in south India, this fibre optic sensor finds great relevance for the detection of adulterants such as paraffin oil or palm oil which are readily miscible in coconut oil. The advantage of this type of sensor is that it is inexpensive and easy to set up. Another attraction of the side-polished fibre is that only a very small amount of analyte is needed and its response time is only 7 s.

Bent Spoke

NASA Image and Video Library

2007-03-07

A bright spoke extends across the unilluminated side of Saturn B ring about the same distance as that from London to Cairo. The background ring material displays some azimuthal i.e., left to right asymmetry

Interference experiment with asymmetric double slit by using 1.2-MV field emission transmission electron microscope.

PubMed

Harada, Ken; Akashi, Tetsuya; Niitsu, Kodai; Shimada, Keiko; Ono, Yoshimasa A; Shindo, Daisuke; Shinada, Hiroyuki; Mori, Shigeo

2018-01-17

Advanced electron microscopy technologies have made it possible to perform precise double-slit interference experiments. We used a 1.2-MV field emission electron microscope providing coherent electron waves and a direct detection camera system enabling single-electron detections at a sub-second exposure time. We developed a method to perform the interference experiment by using an asymmetric double-slit fabricated by a focused ion beam instrument and by operating the microscope under a "pre-Fraunhofer" condition, different from the Fraunhofer condition of conventional double-slit experiments. Here, pre-Fraunhofer condition means that each single-slit observation was performed under the Fraunhofer condition, while the double-slit observations were performed under the Fresnel condition. The interference experiments with each single slit and with the asymmetric double slit were carried out under two different electron dose conditions: high-dose for calculation of electron probability distribution and low-dose for each single electron distribution. Finally, we exemplified the distribution of single electrons by color-coding according to the above three types of experiments as a composite image.

NEI for Kids: Glossary

MedlinePlus

... Astigmatism (uh-STIG-muh-tiz-um) occurs when light is bent differently depending on where it strikes ... of your eye. It helps your eye focus light so things look sharp and clear. D Diabetes ( ...

Gas-Diverting Cup For Welding At An Angle

NASA Technical Reports Server (NTRS)

Dyer, G. E.

1988-01-01

Attachment makes automatic arc welders more versatile. Stainless-steel diverting cup slips over standard torch cup. Bent electrode inserted in torch. Assembly reaches weld joints inaccessible to straight welding torch.

7 CFR 51.1412 - Well cured.

Code of Federal Regulations, 2010 CFR

2010-01-01

... kernel separates freely from the shell, breaks cleanly when bent, without splintering, shattering, or loosening the skin; and the kernel appears to be in good shipping or storage condition as to moisture...

A new technique to expose the hypopharyngeal space: The modified Killian's method.

PubMed

Sakai, Akihiro; Okami, Kenji; Sugimoto, Ryousuke; Ebisumoto, Koji; Yamamoto, Hikaru; Maki, Daisuke; Saito, Kosuke; Iida, Masahiro

2014-04-01

Recent remarkable progress in endoscopic technology has enabled the detection of superficial cancers that were undetectable in the past. However, even though advanced endoscopic technology can detect early lesions, it is useless unless it can provide wide exposure of an area. By modifying the Killian position, it is possible to observe a wider range of the hypopharyngeal space than is possible with conventional head positions. We report a revolutionary method that uses a new head position to widely open the hypopharynx. The technique is named "the Modified Killian's method." The patient is initially placed in the Killian position and then bent further forward from the original position (i.e., the modified Killian position). While in this position, the patient's head is turned and the Valsalva maneuver is applied. These additional maneuvers constitute the Modified Killian's method and widely expands the hypopharyngeal space. The conventional head position cannot open the hypopharyngeal space sufficiently; however, the Modified Killian's method opens the hypopharyngeal space very widely. The Modified Killian's method enables observation of the entire circumference of the hypopharyngeal space and the cervical esophageal entry. The Modified Killian's method may become an indispensable technique for observing the hypopharynx and detecting hypopharyngeal cancers. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Long-Lived Triplet Excited States of Bent-Shaped Pentacene Dimers by Intramolecular Singlet Fission.

PubMed

Sakuma, Takao; Sakai, Hayato; Araki, Yasuyuki; Mori, Tadashi; Wada, Takehiko; Tkachenko, Nikolai V; Hasobe, Taku

2016-03-24

Intramolecular singlet fission (ISF) is a promising photophysical process to construct more efficient light energy conversion systems as one excited singlet state converts into two excited triplet states. Herein we synthesized and evaluated bent-shaped pentacene dimers as a prototype of ISF to reveal intrinsic characters of triplet states (e.g., lifetimes of triplet excited states). In this study, meta-phenylene-bridged TIPS-pentacene dimer (PcD-3Ph) and 2,2'-bipheynyl bridged TIPS-pentacene dimer (PcD-Biph) were newly synthesized as bent-shaped dimers. In the steady-state spectroscopy, absorption and emission bands of these dimers were fully characterized, suggesting the appropriate degree of electronic coupling between pentacene moieties in these dimers. In addition, the electrochemical measurements were also performed to check the electronic interaction between two pentacene moieties. Whereas the successive two oxidation peaks owing to the delocalization were observed in a directly linked-pentacene dimer (PcD) by a single bond, the cyclic voltammograms in PcD-Biph and PcD-3Ph implied the weaker interaction compared to that of p-phenylene-bridged TIPS-pentacene dimer (PcD-4Ph) and PcD. The femtosecond and nanosecond transient absorption spectra clearly revealed the slower ISF process in bent-shaped pentacene dimers (PcD-Biph and PcD-3Ph), more notably, the slower relaxation of the excited triplet states in PcD-Biph and PcD-3Ph. Namely, the quantum yields of triplet states (ΦT) by ISF approximately remain constant (ca. 180-200%) in all dimer systems, whereas the lifetimes of the triplet excited states became much longer (up to 360 ns) in PcD-Biph as compared to PcD-4Ph (15 ns). Additionally, the lifetimes of the corresponding triplet states in PcD-Biph and PcD-3Ph were sufficiently affected by solvent viscosity. In particular, the lifetimes of PcD-Biph triplet state in THF/paraffin (1.0 μs) increased up to approximately three times as compared to that in THF (360 ns), whereas those of PcD-4Ph were quite similar in both solvent.

An optical MEMS accelerometer fabricated using double-sided deep reactive ion etching on silicon-on-insulator wafer

NASA Astrophysics Data System (ADS)

Teo, Adrian J. T.; Li, Holden; Tan, Say Hwa; Yoon, Yong-Jin

2017-06-01

Optical MEMS devices provide fast detection, electromagnetic resilience and high sensitivity. Using this technology, an optical gratings based accelerometer design concept was developed for seismic motion detection purposes that provides miniaturization, high manufacturability, low costs and high sensitivity. Detailed in-house fabrication procedures of a double-sided deep reactive ion etching (DRIE) on a silicon-on-insulator (SOI) wafer for a micro opto electro mechanical system (MOEMS) device are presented and discussed. Experimental results obtained show that the conceptual device successfully captured motion similar to a commercial accelerometer with an average sensitivity of 13.6 mV G-1, and a highest recorded sensitivity of 44.1 mV G-1. A noise level of 13.5 mV was detected due to experimental setup limitations. This is the first MOEMS accelerometer developed using double-sided DRIE on SOI wafer for the application of seismic motion detection, and is a breakthrough technology platform to open up options for lower cost MOEMS devices.

Preliminary evaluation of a nest usage sensor to detect double nest occupations of laying hens.

PubMed

Zaninelli, Mauro; Costa, Annamaria; Tangorra, Francesco Maria; Rossi, Luciana; Agazzi, Alessandro; Savoini, Giovanni

2015-01-26

Conventional cage systems will be replaced by housing systems that allow hens to move freely. These systems may improve hens' welfare, but they lead to some disadvantages: disease, bone fractures, cannibalism, piling and lower egg production. New selection criteria for existing commercial strains should be identified considering individual data about laying performance and the behavior of hens. Many recording systems have been developed to collect these data. However, the management of double nest occupations remains critical for the correct egg-to-hen assignment. To limit such events, most systems adopt specific trap devices and additional mechanical components. Others, instead, only prevent these occurrences by narrowing the nest, without any detection and management. The aim of this study was to develop and test a nest usage "sensor", based on imaging analysis, that is able to automatically detect a double nest occupation. Results showed that the developed sensor correctly identified the double nest occupation occurrences. Therefore, the imaging analysis resulted in being a useful solution that could simplify the nest construction for this type of recording system, allowing the collection of more precise and accurate data, since double nest occupations would be managed and the normal laying behavior of hens would not be discouraged by the presence of the trap devices.

World distribution of the T833C/844INS68 CBS in cis double mutation: a reliable anthropological marker.

PubMed

Pepe, G; Vanegas, O C; Rickards, O; Giusti, B; Comeglio, P; Brunelli, T; Marcucci, R; Prisco, D; Gensini, G F; Abbate, R

1999-02-01

Mild hyperhomocysteinemia is associated to mutations either in cystathionine beta-synthase (CBS) or in 5,10-methylenetetrahydrofolate reductase (MTHFR) genes. In 1995, Sebastio et al. characterized a 68 bp insertion in cis with the most common CBS mutation (T833C) detected in homocystinuric patients. Recently, this double mutation has been detected in Italian and North-American controls. Compared to a group of patients affected by coronary artery disease, North-American controls showed not statistically significant difference. Moreover, Italian controls displayed a microheterogeneity in the mutant allele frequency distribution depending on their geographical origin (North or South of Italy). Aim of our study was to evaluate the prevalence of the double in cis mutation in different populations. We studied 377 healthy subjects belonging to various human groups. Genomic DNA, extracted from peripheral blood samples, was amplified using specific primers; PCR fragments were digested with Bsr I restriction enzyme to detect the double mutation. Our data show a significant heterogeneity among the populations studied, therefore this mutation turned out to be a reliable anthropogenetic marker. The distribution of the double mutation will contribute, with other DNA polymorphisms, to evaluate the genetic admixture of mixed populations such as Afro-Americans.

Preliminary Evaluation of a Nest Usage Sensor to Detect Double Nest Occupations of Laying Hens

PubMed Central

Zaninelli, Mauro; Costa, Annamaria; Tangorra, Francesco Maria; Rossi, Luciana; Agazzi, Alessandro; Savoini, Giovanni

2015-01-01

Conventional cage systems will be replaced by housing systems that allow hens to move freely. These systems may improve hens' welfare, but they lead to some disadvantages: disease, bone fractures, cannibalism, piling and lower egg production. New selection criteria for existing commercial strains should be identified considering individual data about laying performance and the behavior of hens. Many recording systems have been developed to collect these data. However, the management of double nest occupations remains critical for the correct egg-to-hen assignment. To limit such events, most systems adopt specific trap devices and additional mechanical components. Others, instead, only prevent these occurrences by narrowing the nest, without any detection and management. The aim of this study was to develop and test a nest usage “sensor”, based on imaging analysis, that is able to automatically detect a double nest occupation. Results showed that the developed sensor correctly identified the double nest occupation occurrences. Therefore, the imaging analysis resulted in being a useful solution that could simplify the nest construction for this type of recording system, allowing the collection of more precise and accurate data, since double nest occupations would be managed and the normal laying behavior of hens would not be discouraged by the presence of the trap devices. PMID:25629704

Double-label immunofluorescence method for simultaneous detection of adenovirus and herpes simplex virus from the eye.

PubMed

Walpita, P; Darougar, S

1989-07-01

The development and application of a double-label immunofluorescence method which has the potential to screen for single or dual infections from any site, in single shell vial cultures, is described. In this study, a total of 1,141 ocular specimens were inoculated in shell vials, centrifuged at 15,000 X g for 1 h, incubated at 37 degrees C for 48 h, and fixed in methanol at room temperature for 15 min. The virus inclusions were detected by staining with a double-label indirect immunofluorescence procedure using mixtures of appropriate first antibodies, followed by fluorescein- and rhodamine-conjugated second antibodies. Each specimen was also inoculated in parallel by the conventional virus isolation method. The sensitivity and specificity of the double-label shell vial procedure were comparable to those with the conventional method, and the former test took only 48 h to complete. The test offers a rapid and simple single-vial procedure which allows for individual or simultaneous detection of multiple pathogens. It results in savings in time and cost over the conventional virus isolation method and other shell vial procedures.

49 CFR 570.61 - Suspension system.

Code of Federal Regulations, 2010 CFR

2010-10-01

... or cracked, other than superficial surface cracks. Ball joints and kingpins shall not be bent or... bushings shall not be cracked, extruded out from or missing from suspension joints. Radius rods shall not...

49 CFR 570.61 - Suspension system.

Code of Federal Regulations, 2011 CFR

2011-10-01

... or cracked, other than superficial surface cracks. Ball joints and kingpins shall not be bent or... bushings shall not be cracked, extruded out from or missing from suspension joints. Radius rods shall not...

49 CFR 570.8 - Suspension systems.

Code of Federal Regulations, 2013 CFR

2013-10-01

... cracked. Structural parts shall not be bent or damaged. Stabilizer bars shall be connected. Springs shall..., shall be installed on both front springs, both rear springs, or on all four springs. Shock absorber...

49 CFR 570.8 - Suspension systems.

Code of Federal Regulations, 2014 CFR

2014-10-01

... cracked. Structural parts shall not be bent or damaged. Stabilizer bars shall be connected. Springs shall..., shall be installed on both front springs, both rear springs, or on all four springs. Shock absorber...

49 CFR 570.8 - Suspension systems.

Code of Federal Regulations, 2011 CFR

2011-10-01

... cracked. Structural parts shall not be bent or damaged. Stabilizer bars shall be connected. Springs shall..., shall be installed on both front springs, both rear springs, or on all four springs. Shock absorber...

49 CFR 570.8 - Suspension systems.

Code of Federal Regulations, 2012 CFR

2012-10-01

... cracked. Structural parts shall not be bent or damaged. Stabilizer bars shall be connected. Springs shall..., shall be installed on both front springs, both rear springs, or on all four springs. Shock absorber...

Double ErrP Detection for Automatic Error Correction in an ERP-Based BCI Speller.

PubMed

Cruz, Aniana; Pires, Gabriel; Nunes, Urbano J

2018-01-01

Brain-computer interface (BCI) is a useful device for people with severe motor disabilities. However, due to its low speed and low reliability, BCI still has a very limited application in daily real-world tasks. This paper proposes a P300-based BCI speller combined with a double error-related potential (ErrP) detection to automatically correct erroneous decisions. This novel approach introduces a second error detection to infer whether wrong automatic correction also elicits a second ErrP. Thus, two single-trial responses, instead of one, contribute to the final selection, improving the reliability of error detection. Moreover, to increase error detection, the evoked potential detected as target by the P300 classifier is combined with the evoked error potential at a feature-level. Discriminable error and positive potentials (response to correct feedback) were clearly identified. The proposed approach was tested on nine healthy participants and one tetraplegic participant. The online average accuracy for the first and second ErrPs were 88.4% and 84.8%, respectively. With automatic correction, we achieved an improvement around 5% achieving 89.9% in spelling accuracy for an effective 2.92 symbols/min. The proposed approach revealed that double ErrP detection can improve the reliability and speed of BCI systems.

Precise Restraightening of Bent Studs

NASA Technical Reports Server (NTRS)

Boardman, R. E.

1982-01-01

Special tool quickly bends studs back into shape accurately and safely by force applied by hydraulic ram, with deflection being measured by dial indicator. Ram and indicator can be interchanged for straightening in reverse direction.

Modeling the Deflection of Polarized Electrons with Energies in the Range 3.35-14 GeV in a Bent Silicon Crystal

NASA Astrophysics Data System (ADS)

Koshcheev, V. P.; Shtanov, Yu. N.; Morgun, D. A.; Panina, T. A.

2018-04-01

The evolution of the magnetic moment of a relativistic particle is described with the help of the Bargmann-Michel-Telegdi equation in the planar channels of a bent silicon crystal with allowance for multiple scatteringboth along and transverse to the (111) atomic plane, which consists of <110> chains. Results of numerical simulations demonstrate a strong dependence of the degree of depolarization of the electron beam on the energy since at the energies 3.35 and 4.2 GeV the maximum in the distribution over rotation angles of the electron spin is absent, and at energies from 6.3 to 14 GeV the position of the maximum is in line with the theoretical estimate obtained using the formula of V. L. Lyuboshits.

Bending and Force Recovery in Polymer Films and Microgel Formation

NASA Astrophysics Data System (ADS)

Elder, Theresa Marie

To determine correlation between geometry and material three different model films: polymethylsiloxane (PDMS), polystyrene (PS), and polycarbonate (PC), were singly bent and doubly bent (forming D-cones). Bends were chosen as they are fundamental in larger complex geometries such as origami and crumples. Bending was carried out between two plates taking force and displacement measurements. Processing of data using moment equations yielded values for bending moduli for studied films that were close to accepted values. Force recovery showed logarithmic trends for PDMS and stretched exponential trends for PS and PC. In a separate experiment a triblock copolymer of polystyrene-polyacrylic acid-polystyrene was subjected to different good and bad solvent mixing with any resulting particle morphology examined. Particles formed more uniformly with high water concentration, particles formed with high toluene concentration and agitation yielded three separate morphologies.

Levelized cost of energy for a Backward Bent Duct Buoy

DOE PAGES

Bull, Diana; Jenne, D. Scott; Smith, Christopher S.; ...

2016-07-18

The Reference Model Project, supported by the U.S. Department of Energy, was developed to provide publicly available technical and economic benchmarks for a variety of marine energy converters. The methodology to achieve these benchmarks is to develop public domain designs that incorporate power performance estimates, structural models, anchor and mooring designs, power conversion chain designs, and estimates of the operations and maintenance, installation, and environmental permitting required. The reference model designs are intended to be conservative, robust, and experimentally verified. The Backward Bent Duct Buoy (BBDB) presented in this paper is one of three wave energy conversion devices studied withinmore » the Reference Model Project. Furthermore, comprehensive modeling of the BBDB in a Northern California climate has enabled a full levelized cost of energy (LCOE) analysis to be completed on this device.« less

Device for reducing vehicle aerodynamic resistance

DOEpatents

Graham, Sean C.

2006-03-07

A device for reducing vehicle aerodynamic resistance for vehicles having a generally rectangular flat front face comprising a plurality of load bearing struts of a predetermined size attached to the flat front face adjacent the sides and top thereof, a pair of pliable opposing flat sheets having an outside edge portion attached to the flat front face adjacent the sides thereof and an upper edge with a predetermined curve; the opposing flat sheets being bent and attached to the struts to form effective curved airfoil shapes, and a top pliable flat sheet disposed adjacent the top of the flat front face and having predetermined curved side edges, which, when the top sheet is bent and attached to the struts to form an effective curved airfoil shape, mate with the curved upper edges of the opposing sheets to complete the aerodynamic device.

Levelized cost of energy for a Backward Bent Duct Buoy

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

Bull, Diana; Jenne, D. Scott; Smith, Christopher S.

2016-12-01

The Reference Model Project, supported by the U.S. Department of Energy, was developed to provide publically available technical and economic benchmarks for a variety of marine energy converters. The methodology to achieve these benchmarks is to develop public domain designs that incorporate power performance estimates, structural models, anchor and mooring designs, power conversion chain designs, and estimates of the operations and maintenance, installation, and environmental permitting required. The reference model designs are intended to be conservative, robust, and experimentally verified. The Backward Bent Duct Buoy (BBDB) presented in this paper is one of three wave energy conversion devices studied withinmore » the Reference Model Project. Comprehensive modeling of the BBDB in a Northern California climate has enabled a full levelized cost of energy (LCOE) analysis to be completed on this device.« less

A new scheme for stigmatic x-ray imaging with large magnification.

PubMed

Bitter, M; Hill, K W; Delgado-Aparicio, L F; Pablant, N A; Scott, S; Jones, F; Beiersdorfer, P; Wang, E; del Rio, M Sanchez; Caughey, T A; Brunner, J

2012-10-01

This paper describes a new x-ray scheme for stigmatic imaging. The scheme consists of one convex spherically bent crystal and one concave spherically bent crystal. The radii of curvature and Bragg reflecting lattice planes of the two crystals are properly matched to eliminate the astigmatism, so that the conditions for stigmatic imaging are met for a particular wavelength. The magnification is adjustable and solely a function of the two Bragg angles or angles of incidence. Although the choice of Bragg angles is constrained by the availability of crystals, this is not a severe limitation for the imaging of plasmas, since a particular wavelength can be selected from the bremsstrahlung continuum. The working principle of this imaging scheme has been verified with visible light. Further tests with x rays are planned for the near future.

Alternating twist structures formed by electroconvection in the nematic phase of an achiral bent-core molecule.

PubMed

Tanaka, Shingo; Dhara, Surajit; Sadashiva, B K; Shimbo, Yoshio; Takanishi, Yoichi; Araoka, Fumito; Ishikawa, Ken; Takezoe, Hideo

2008-04-01

We report an unusual electroconvection in the nematic phase of a bent-core liquid crystal. In a voltage-frequency diagram, two frequency regions exhibiting prewavy stripe patterns were found, as reported by Wiant We found that these stripes never show extinction dark when cells were rotated under crossed polarizers. Based on the color interchange in between neighboring stripes by the rotation of the cells or an analyzer, twisted molecular orientation is suggested; i.e., the directors are alternately twisted from the top to the bottom surfaces with a pretilt angle in adjacent stripes, which is an analogue of the twisted (splayed) structure observed in surface-stabilized ferroelectric liquid crystal cells. The transmittance spectra calculated using the 4x4 matrix method from the model structure are consistent with the experimental observation.

Integrated source and channel encoded digital communication system design study

NASA Technical Reports Server (NTRS)

Alem, W. K.; Huth, G. K.; Simon, M. K.

1978-01-01

The particular Ku-band carrier, PN despreading, and symbol synchronization strategies, which were selected for implementation in the Ku-band transponder aboard the orbiter, were assessed and evaluated from a systems performance viewpoint, verifying that system specifications were met. A study was performed of the design and implementation of tracking techniques which are suitable for incorporation into the Orbiter Ku-band communication system. Emphasis was placed on maximizing tracking accuracy and communication system flexibility while minimizing cost, weight, and system complexity of Orbiter and ground systems hardware. The payload communication study assessed the design and performance of the forward link and return link bent-pipe relay modes for attached and detached payloads. As part of this study, a design for a forward link bent-pipe was proposed which employs a residual carrier but which is tracked by the existing Costas loop.

Bent-core fiber structure: Experimental and theoretical studies of fiber stability

NASA Astrophysics Data System (ADS)

Bailey, C.; Gartland, E.; Jakli, A.

2007-03-01

Recent studies have shown that bent core liquid crystals in the B7 and B2 phases can form stable freestanding fibers with a so called ``jelly-roll'' layer configuration, which means that the smectic layers would be arranged in concentric cylindrical shells. This configuration shows layer curvature is necessary for fiber stability. Classically this effect would destabilize the fiber configuration because of the energy cost of layer distortions and surface tension. We propose a model that can predict fiber stability in the experimentally observed range of a few micrometers, by assuming that layer curvature can be stabilized by including a term dealing with the linear divergence of the polarization direction if the polarization is allowed to have a component normal to the smectic layers. We show that this term can stabilize the fiber configuration if its strength is larger than the surface tension. We also propose an entropic model to explain the strength of this term by considering steric effects. Finally we will take results from this model and apply them to better understand experimental findings of bent-core fibers. Financial support by NSF FRG under contract DMS-0456221. Prof. Daniel Phillips, Particia Bauman and Jie Shen at Purdue Univ., Prof. Maria Carme Calderer at Univ. of Minnesota, and Prof. Jonathan Selinger at Kent State Univ. Liou Qiu and Dr. O.D. Lavrentovich, Characterization Facilities, Liquid Crystal Institute, Kent State Univ. Julie Kim and Dr. Quan Li, Chemical Synthesis Facilities, Liquid Crystal Institute, Kent State Univ.

Peeling behavior and spalling resistance of CFRP sheets bonded to bent concrete surfaces

NASA Astrophysics Data System (ADS)

Yuan, Hong; Li, Faping

2010-05-01

In this paper, the peeling behavior and the spalling resistance effect of carbon fiber reinforced polymer (CFRP) sheets externally bonded to bent concrete surfaces are firstly investigated experimentally. Twenty one curved specimens and seven plane specimens are studied in the paper, in which curved specimens with bonded CFRP sheets can simulate the concrete spalling in tunnel, culvert, arch bridge etc., whereas plane specimens with bonded CFRP sheets can simulate the concrete spalling in beam bridge, slab bridge and pedestrian bridge. Three kinds of curved specimens with different radii of curvature are chosen by referring to practical tunnel structures, and plane specimens are used for comparison with curved ones. A peeling load is applied on the FRP sheet by loading a circular steel tube placed into the central notch of beam to debond CFRP sheets from the bent concrete surface, meanwhile full-range load-deflection curves are recorded by a MTS 831.10 Elastomer Test System. Based on the experimental results, a theoretical analysis is also conducted for the specimens. Both theoretical and experimental results show that only two material parameters, the interfacial fracture energy of CFRP-concrete interface and the tensile stiffness of CFRP sheets, are needed for describing the interfacial spalling behavior. It is found that the radius of curvature has remarkable influence on peeling load-deflection curves. The test methods and test results given in the paper are helpful and available for reference to the designer of tunnel strengthening.

Colloid-Colloid Hydrodynamic Interaction Around a Bend in a Quasi-One-Dimensional Channel

NASA Astrophysics Data System (ADS)

Liepold, Christopher; Zarcone, Ryan; Heumann, Tibor; Lin, Binhua; Rice, Stuart

We report a study of the correlation between a pair of particles in a colloid suspension in a bent quasi-one-dimensional (q1d) channel as a function of bend angle. As the bend angle becomes more acute, we observe an increasing depletion of particles in the vicinity of the bend and an increase in the nearest-neighbor separation in the pair correlation function for particles on opposite sides of the bend. Further, we observe that the peak value of D12, the coupling term in the pair diffusion tensor that characterizes the effect of the motion of particle 1 on particle 2, coincides with the first peak in the pair correlation function, and that the pair separation dependence of D12 mimics that of the pair correlation function. We show that the observed behavior is a consequence of the geometric constraints imposed by the single-file requirement that the particle centers lie on the centerline of the channel and the requirement that the hydrodynamic flow must follow the channel around the bend. We find that the correlation between a pair of particles in a colloidal suspension in a bent q1D channel has the same functional dependence on the pair correlation function as in a straight q1D channel when measured in a coordinate system that follows the centerline of the bent channel. NSF MRSEC (DMR-1420709), Dreyfus Foundation (SI-14-014).

Biaxial and antiferroelectric structure of the orthogonal smectic phase of a bent-shaped molecule and helical structure in a chiral mixture system

NASA Astrophysics Data System (ADS)

Kang, Sungmin; Nguyen, Ha; Nakajima, Shunpei; Tokita, Masatoshi; Watanabe, Junji

2013-05-01

We examined the biaxial and antiferroelectric properties in the Smectic-APA (Sm-APA) phase of bent-shaped DC-S-8. The biaxiality, which results from the existence of a secondary director, was well established from birefringence observations in the homeotropically aligned Sm-APA. By entering into Sm-APA phase, the birefringence (Δn, difference between two refractive indices of short axes) continuously increased from 0 to 0.02 with decreasing temperature. The antiferroelectric switching and second harmonic generation (SHG) activity on the field-on state were also observed in the Sm-APA phase, and the evaluated spontaneous polarization (PS) value strongly depended on temperature. The temperature dependence of Δn and PS resembles each other and follows Haller's approximation, showing that the biaxiality is due to polar packing in which the molecules are preferentially packed with their bent direction arranged in the same direction, and that the phase transition of Sm-APA to Sm-A is second order. The biaxiality was further examined in chiral Sm-APA*. Doping with chiral components induced the helical twisting of the secondary director in the Sm-APA* phase, which was confirmed by observing the reflection of the circular dichroism (CD) bands in the homeotropically aligned cell. The helical pitch of Sm-APA* is tunable in the range of 300-700 nm wavelength with a variation in the chiral content of 5 to 10 weight (wt)%.

Bent CNN bond of diazo compounds, RR'(Cdbnd N+dbnd N-)

NASA Astrophysics Data System (ADS)

Akita, Motoko; Takahashi, Mai; Kobayashi, Keiji; Hayashi, Naoto; Tukada, Hideyuki

2013-02-01

The reaction of ninhydrin with benzophenone hydrazone afforded 2-diazo-3-diphenylmethylenehydrazono-1-indanone 1 and 2-diazo-1,3-bis(diphenylmethylenehydrazono)indan 2. X-ray crystal structure analyses of these products showed that the diazo functional group Cdbnd N+dbnd N- of 1 is bent by 172.9°, while that of 2 has a linear geometry. The crystal structure data of diazo compounds have been retrieved from the Cambridge Structural Database (CSD), which hit 177 entries to indicate that the angle of 172.9° in 1 lies in one of the most bent structures. The CSD search also indicated that diazo compounds consisting of a distorted diazo carbon tend to bend the Cdbnd N+dbnd N- bond. On the basis of DFT calculations (B3LYP/6-311++G(d,p)) of model compounds, it was revealed that the bending of the CNN bond is principally induced by steric factors and that the neighboring carbonyl group also plays a role in bending toward the carbonyl side owing to an electrostatic attractive interaction. The potential surface along the path of Cdbnd N+dbnd N- bending in 2-diazopropane shows a significantly shallow profile with only 4 kcal/mol needed to bend the Cdbnd N+dbnd N- bond from 180° to 160°. Thus, the bending of the diazo group in 1 is reasonable as it is provided with all of the factors for facile bending disclosed in this investigation.

A flexible and wearable terahertz scanner

NASA Astrophysics Data System (ADS)

Suzuki, D.; Oda, S.; Kawano, Y.

2016-12-01

Imaging technologies based on terahertz (THz) waves have great potential for use in powerful non-invasive inspection methods. However, most real objects have various three-dimensional curvatures and existing THz technologies often encounter difficulties in imaging such configurations, which limits the useful range of THz imaging applications. Here, we report the development of a flexible and wearable THz scanner based on carbon nanotubes. We achieved room-temperature THz detection over a broad frequency band ranging from 0.14 to 39 THz and developed a portable THz scanner. Using this scanner, we performed THz imaging of samples concealed behind opaque objects, breakages and metal impurities of a bent film and multi-view scans of a syringe. We demonstrated a passive biometric THz scan of a human hand. Our results are expected to have considerable implications for non-destructive and non-contact inspections, such as medical examinations for the continuous monitoring of health conditions.

Double triplex real-time PCR assay for simultaneous detection of Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus hominis, and Staphylococcus haemolyticus and determination of their methicillin resistance directly from positive blood culture bottles.

PubMed

Kilic, Abdullah; Basustaoglu, A Celal

2011-12-01

We developed and validated here a double triplex real-time PCR assay to simultaneously detect and identify Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus hominis, Staphylococcus haemolyticus and their methicillin resistance in a single reaction directly from Gram-positive cocci-in-clusters (GPCs)-positive blood culture bottles. From August 15, 2009 through February 15, 2010, 238 GPC-positive samples were collected and identified by conventional methods as 11 methicillin-resistant S. aureus (MRSA), 28 methicillin-susceptible S. aureus (MSSA), 176 MR coagulase-negative staphylococci (MRCoNS), 21 MSCoNS and two Enterococcus faecalis. The double triplex real-time PCR assay was targeted and detected tuf, nuc and mecA genes in the first tube and atlE, gap and mvaA genes in the second tube which could be run simultaneously. The detection limit of the assay was found at 10(3) CFU/ml for the atleE gene, 10(4) CFU/ml for the mva gene and 10(5) CFU/ml for gap, nuc, mecA and tuf genes based on seeding experiments. All Staphylococcus species except two S. epidermidis were correctly identified by the assay. The double triplex real-time PCR assay quickly and accurately detects S. aureus, S. epidermidis, S. hominis and S. haemolyticus and their methicillin resistance in a single reaction directly from positive blood culture bottles within 83 min. Copyright © 2011 Institut Pasteur. All rights reserved.

Label-free CMOS bio sensor with on-chip noise reduction scheme for real-time quantitative monitoring of biomolecules.

PubMed

Seong-Jin Kim; Euisik Yoon

2012-06-01

We present a label-free CMOS field-effect transistor sensing array to detect the surface potential change affected by the negative charge in DNA molecules for real-time monitoring and quantification. The proposed CMOS bio sensor includes a new sensing pixel architecture implemented with correlated double sampling for reducing offset fixed pattern noise and 1/f noise of the sensing devices. We incorporated non-surface binding detection which allows real-time continuous monitoring of DNA concentrations without immobilizing them on the sensing surface. Various concentrations of 19-bp oligonucleotides solution can be discriminated using the prototype device fabricated in 1- μm double-poly double-metal standard CMOS process. The detection limit was measured as 1.1 ng/μl with a dynamic range of 40 dB and the transient response time was measured less than 20 seconds.

Detecting double compression of audio signal

NASA Astrophysics Data System (ADS)

Yang, Rui; Shi, Yun Q.; Huang, Jiwu

2010-01-01

MP3 is the most popular audio format nowadays in our daily life, for example music downloaded from the Internet and file saved in the digital recorder are often in MP3 format. However, low bitrate MP3s are often transcoded to high bitrate since high bitrate ones are of high commercial value. Also audio recording in digital recorder can be doctored easily by pervasive audio editing software. This paper presents two methods for the detection of double MP3 compression. The methods are essential for finding out fake-quality MP3 and audio forensics. The proposed methods use support vector machine classifiers with feature vectors formed by the distributions of the first digits of the quantized MDCT (modified discrete cosine transform) coefficients. Extensive experiments demonstrate the effectiveness of the proposed methods. To the best of our knowledge, this piece of work is the first one to detect double compression of audio signal.

Detection of shifted double JPEG compression by an adaptive DCT coefficient model

NASA Astrophysics Data System (ADS)

Wang, Shi-Lin; Liew, Alan Wee-Chung; Li, Sheng-Hong; Zhang, Yu-Jin; Li, Jian-Hua

2014-12-01

In many JPEG image splicing forgeries, the tampered image patch has been JPEG-compressed twice with different block alignments. Such phenomenon in JPEG image forgeries is called the shifted double JPEG (SDJPEG) compression effect. Detection of SDJPEG-compressed patches could help in detecting and locating the tampered region. However, the current SDJPEG detection methods do not provide satisfactory results especially when the tampered region is small. In this paper, we propose a new SDJPEG detection method based on an adaptive discrete cosine transform (DCT) coefficient model. DCT coefficient distributions for SDJPEG and non-SDJPEG patches have been analyzed and a discriminative feature has been proposed to perform the two-class classification. An adaptive approach is employed to select the most discriminative DCT modes for SDJPEG detection. The experimental results show that the proposed approach can achieve much better results compared with some existing approaches in SDJPEG patch detection especially when the patch size is small.

Behavior and design of large structural concrete bridge pier overhangs.

DOT National Transportation Integrated Search

1997-02-01

In designing large cantilever bent caps for use on recent projects under current AASHTO design specifications, : designers were faced with considerable uncertainties. Questions arose when designers attempted to satisfy : both serviceability and stren...

40 CFR 270.18 - Specific part B information requirements for waste piles.

Code of Federal Regulations, 2013 CFR

2013-07-01

... future time; (ii) The double liner and leak (leachate) detection, collection, and removal system, if the..., where applicable; (d) A description of how each waste pile, including the double liner system, leachate...

40 CFR 270.18 - Specific part B information requirements for waste piles.

Code of Federal Regulations, 2012 CFR

2012-07-01

... future time; (ii) The double liner and leak (leachate) detection, collection, and removal system, if the..., where applicable; (d) A description of how each waste pile, including the double liner system, leachate...

40 CFR 270.18 - Specific part B information requirements for waste piles.

Code of Federal Regulations, 2014 CFR

2014-07-01

... future time; (ii) The double liner and leak (leachate) detection, collection, and removal system, if the..., where applicable; (d) A description of how each waste pile, including the double liner system, leachate...

Analysis of Vibrational Harmonic Response for Printing Double-Sheet Detecting System via ANSYS

NASA Astrophysics Data System (ADS)

Guo, Qiang; Cai, Ji-Fei; Wang, Yan; Zhang, Yang

In order to explore the influence of the harmonic response of system vibration upon the stability of the double-sheet detector system, the mathematical model of vibrational system is established via the mechanical dynamic theory. Vibrational system of double-sheet detector is studied by theoretical modeling, and the dynamic simulation to obtain the amplitude/phase frequency response curve of the system based on ANSYS is completed to make a comparison with the theoretical results. It is shown that the theoretical value is basically consistent with that calculated through ANSYS. Conclusion vibrational characteristics of double-sheet detection system is obtained quickly and accurately, and propound solving measures by some crucial factors, such as the harmonic load, mass and stiffness, which will affect the vibration of the system, contribute to the finite element method is applied to the complex multiple-degree-of-freedom system.

Double heterozygosity for Hb New York [beta 113 GTG-->GAG; VAL-->GLU] and beta degrees-thalassemia mutations manifests as a thalassemia trait.

PubMed

Lee, Anselm C W; Ma, Edmond S K; Chan, Amy Y Y; Szeto, S C; Chan, L C

2008-01-01

An extended family with three individuals affected by two different forms of double heterozygosity for beta-thalassemia and Hb New York is reported. Double heterozygosity of Hb New York [beta 113 GTG-->GAG; VAL-->GLU] and beta degrees codon 17 was detected in a fetus following prenatal screening for thalassemia. The father and a paternal aunt were also found to be heterozygous for Hb New York and beta degrees IVSII-654. Both adults had clinical and hematological features consistent with beta-thalassemia trait. The affected child was followed up after birth and manifested the typical course of a thalassemia trait, with no signs of organomegaly or overt hemolysis. Observations strongly suggest that double heterozygosity of Hb New York and beta degrees thalassemia has mild, if any, clinical symptoms, and is not an indication of therapeutic abortion when detected antenatally.

Strain tolerance in technical Nb3Al superconductors

NASA Astrophysics Data System (ADS)

Banno, N.; Takeuchi, T.; Kitaguchi, H.; Tagawa, K.

2006-10-01

We observed crack formation in transformation-processed Nb3Al wires at room temperature, the wire being bent with a small clamp fixture with a curvature. The polished cross-section parallel to the longitudinal axis was observed, using a high power optical microscope or a field-emission scanning electron microscope. The bend strain limit for microcrack formation is found, changing the radius of the curvature of the clamp. The bend strain limit was found to be around 0.3% for standard Nb3Al wires. This corresponds to the irreversible tensile strain limit of the Ic characteristics determined with a 0.1 µV cm-1 criterion. Reduction of the barrier thickness should be avoided to keep to the bend strain limit. A new configuration of the Nb3Al wire is demonstrated to improve the bend strain limit. The filament is divided into segments in the transverse cross-section. The wire is fabricated by a double-stacking method. The bend strain limit is enhanced to about 0.85% for the wire surface; the equivalent strain of the outermost filament location is about 0.66%. A simple react and wind test for this wire was performed, where the wire experienced 0.86% bend strain. The degradation of Jc was found to be very small.

Beamlines of the Biomedical Imaging and Therapy Facility at the Canadian Light Source - Part 2

NASA Astrophysics Data System (ADS)

Wysokinski, T. W.; Chapman, D.; Adams, G.; Renier, M.; Suortti, P.; Thomlinson, W.

2013-03-01

The BioMedical Imaging and Therapy (BMIT) facility provides a world class facility with unique synchrotron-specific imaging and therapy capabilities. This paper describes Insertion Device (ID) beamline 05ID-2 with the beam terminated in the first experimental hutch: POE-2. The experimental methods available in POE-2 include: Microbeam Radiation Therapy (MRT), Synchrotron Stereotactic Radiation Therapy (SSRT) and absorption imaging (projection and Computed Tomography (CT)). The source for the ID beamline is a multi-pole superconductive 4.3 T wiggler, which can generate ~30 kW of radiative power and deliver dose as high as 3000 Gy/s required for MRT program. The optics in POE-1 hutch prepares either monochromatic or filtered white beam that is used in POE-2. The Double Crystal (DC), bent Laue monochromator will prepare a beam over 10 cm wide at sample point, while spanning an energy range appropriate for imaging studies of animals (20-100+ keV). The experimental hutch will have a flexible positioning system that can handle subjects up to 120 kg. Several different cameras will be available with resolutions ranging from 4 μm to 150 μm. The latest update on the status of 05B1-1 bending magnet (BM) beamline, described in Part 1 [1], is also included.

Hydrogen-peroxide-modified egg albumen for transparent and flexible resistive switching memory

NASA Astrophysics Data System (ADS)

Zhou, Guangdong; Yao, Yanqing; Lu, Zhisong; Yang, Xiude; Han, Juanjuan; Wang, Gang; Rao, Xi; Li, Ping; Liu, Qian; Song, Qunliang

2017-10-01

Egg albumen is modified by hydrogen peroxide with concentrations of 5%, 10%, 15% and 30% at room temperature. Compared with devices without modification, a memory cell of Ag/10% H2O2-egg albumen/indium tin oxide exhibits obviously enhanced resistive switching memory behavior with a resistance ratio of 104, self-healing switching endurance for 900 cycles and a prolonged retention time for a 104 s @ 200 mV reading voltage after being bent 103 times. The breakage of massive protein chains occurs followed by the recombination of new protein chain networks due to the oxidation of amidogen and the synthesis of disulfide during the hydrogen peroxide modifying egg albumen. Ions such as Fe3+, Na+, K+, which are surrounded by protein chains, are exposed to the outside of protein chains to generate a series of traps during the egg albumen degeneration process. According to the fitting results of the double logarithm I-V curves and the current-sensing atomic force microscopy (CS-AFM) images of the ON and OFF states, the charge transfer from one trap center to its neighboring trap center is responsible for the resistive switching memory phenomena. The results of our work indicate that hydrogen- peroxide-modified egg albumen could open up a new avenue of biomaterial application in nanoelectronic systems.

Microwave spectrum of 2-aminooxazole, a compound of potential prebiotic and astrochemical interest.

PubMed

Møllendal, Harald; Konovalov, Alexey

2010-02-11

The microwave spectrum in the 26.6-80 GHz spectral range of 2-aminooxazole, which may have played a potential role in the prebiotic generation of pyrimidine ribonucleotides, is reported. A large number of transitions have been assigned, and accurate values of the rotational and quartic centrifugal distortion constants have been obtained for the four lowest vibrational states. The frequencies of the vibrationally excited states have been determined by relative intensity measurements. The microwave spectra should be useful for the identification of this compound in planetary atmospheres or in interstellar space. 2-Aminooxazole is nonplanar with the amino group bent 35(5) degrees out of the oxazole plane. Inversion of the amino group manifests itself in a characteristic doubling of the microwave transitions and the absence of c-type transitions. The microwave work has been augmented by quantum chemical calculations at the MP2/aug-cc-pVTZ and B3LYP/6-311++G(3df,3pd) levels of theory. The spectroscopic constants obtained by these two methods are in good agreement with one another, as well as with their experimental counterparts. The B3LYP method predicts a more accurate value for the angle between the oxazole ring and the plane formed by the amino group than the MP2 procedure.

A paper-based device for double-stranded DNA detection with Zif268

NASA Astrophysics Data System (ADS)

Zhang, Daohong

2017-05-01

Here, a small analytical device was fabricated on both nitrocellulose membrane and filter paper, for the detection of biotinylated double-stranded DNA (dsDNA) from 1 nM. Zif268 was utilized for capturing the target DNA, which was a zinc finger protein that recognized only a dsDNA with specific sequence. Therefore, this detection platform could be utilized for PCR result detection, with the well-designed primers (interpolate both biotin and Zif268 binding sequence). The result of the assay could be recorded by a camera-phone, and analyzed with software. The whole assay finished within 1 hour. Due to the easy fabrication, operation and disposal of this device, this method can be employed in point-of-care detection or on-site monitoring.

Double-labeled donor probe can enhance the signal of fluorescence resonance energy transfer (FRET) in detection of nucleic acid hybridization

PubMed Central

Okamura, Yukio; Kondo, Satoshi; Sase, Ichiro; Suga, Takayuki; Mise, Kazuyuki; Furusawa, Iwao; Kawakami, Shigeki; Watanabe, Yuichiro

2000-01-01

A set of fluorescently-labeled DNA probes that hybridize with the target RNA and produce fluorescence resonance energy transfer (FRET) signals can be utilized for the detection of specific RNA. We have developed probe sets to detect and discriminate single-strand RNA molecules of plant viral genome, and sought a method to improve the FRET signals to handle in vivo applications. Consequently, we found that a double-labeled donor probe labeled with Bodipy dye yielded a remarkable increase in fluorescence intensity compared to a single-labeled donor probe used in an ordinary FRET. This double-labeled donor system can be easily applied to improve various FRET probes since the dependence upon sequence and label position in enhancement is not as strict. Furthermore this method could be applied to other nucleic acid substances, such as oligo RNA and phosphorothioate oligonucleotides (S-oligos) to enhance FRET signal. Although the double-labeled donor probes labeled with a variety of fluorophores had unexpected properties (strange UV-visible absorption spectra, decrease of intensity and decay of donor fluorescence) compared with single-labeled ones, they had no relation to FRET enhancement. This signal amplification mechanism cannot be explained simply based on our current results and knowledge of FRET. Yet it is possible to utilize this double-labeled donor system in various applications of FRET as a simple signal-enhancement method. PMID:11121494

Breast cancer detection using double reading of unenhanced MRI including T1-weighted, T2-weighted STIR, and diffusion-weighted imaging: a proof of concept study.

PubMed

Trimboli, Rubina M; Verardi, Nicola; Cartia, Francesco; Carbonaro, Luca A; Sardanelli, Francesco

2014-09-01

The purpose of this study was to investigate the diagnostic performance of unenhanced MRI in detecting breast cancer and to assess the impact of double reading. A total of 116 breasts of 67 women who were 36-89 years old were studied at 1.5 T using an unenhanced protocol including axial T1-weighted gradient-echo, T2-weighted STIR, and echo-planar diffusion-weighted imaging (DWI). Two blinded readers (R1 and R2) independently evaluated unenhanced images using the BIRADS scale. A combination of pathology and negative follow-up served as the reference standard. McNemar and kappa statistics were used. Per-breast cancer prevalence was 37 of 116 (32%): 30 of 37 (81%) invasive ductal carcinoma, five of 37 (13%) ductal carcinoma in situ, and two of 37 (6%) invasive lobular carcinoma. Per-breast sensitivity of unenhanced MRI was 29 of 37 (78%) for R1, 28 of 37 (76%) for R2, and 29 of 37 (78%) for double reading. Specificity was 71 of 79 (90%) for both R1 and R2 and 69 of 79 (87%) for double reading. Double reading did not provide a significant increase in sensitivity. Interobserver agreement was almost perfect (Cohen κ = 0.873). An unenhanced breast MRI protocol composed of T1-weighted gradient echo, T2-weighted STIR, and echo-planar DWI enabled breast cancer detection with sensitivity of 76-78% and specificity of 90% without a gain in sensitivity from double reading.

[Usefulness of systematic chromoendoscopy with a double dye staining technique for the detection of dysplasia in patients with premalignant gastric lesions].

PubMed

Yep-Gamarra, Víctor; Díaz-Vélez, Cristian; Araujo, Isis; Ginès, Àngels; Fernández-Esparrach, Gloria

2016-02-01

Premalignant gastric lesions have an increased risk to develop gastric cancer. To evaluate the usefulness of systematic endoscopy that includes chromoendoscopy with a double dye staining technique for the detection of dysplasia in patients with premalignant gastric lesions. This longitudinal, prospective study was performed in patients with gastric atrophy, intestinal metaplasia or dysplasia who were referred for endoscopy less than 6 months after the initial diagnosis. The second endoscopy was performed in three phases: phase 1, exhaustive and systematic review of the mucosa with photographic documentation and biopsies of suspicious areas; phase 2, chromoendoscopy with a double dye staining technique using acetic acid 1.2% and indigo carmine 0.5%; phase 3, topographic mapping and random biopsies. A total of 50 patients were included. Nine (18%) had atrophic gastritis, 38 (76%) had intestinal metaplasia, and 3 (6%) had low-grade dysplasia. Systematic endoscopy with chromoendoscopy using a double dye staining technique detected more patients with dysplasia (9 versus 3, p<.05), and a larger number of biopsies with the diagnosis of dysplasia were obtained. This occurred for visible (6 vs. 0, p<.05) and non-visible lesions (6 vs. 3, p=NS). In one patient, initial low-grade dysplasia was not detected again in the systematic endoscopy, giving a global endoscopic performance for the detection of lesions of 92%. Patients with premalignant gastric lesions have synchronous lesions with greater histological severity, which are detected when systematic endoscopy is conducted with indigo carmine dye added to acetic acid. Copyright © 2015 Elsevier España, S.L.U. and AEEH y AEG. All rights reserved.

Ortho-positronium observation in the Double Chooz experiment

DOE PAGES

Abe, Y.; dos Anjos, J. C.; Barriere, J. C.; ...

2014-10-01

The Double Chooz experiment measures the neutrino mixing angle θ13 by detecting reactor ν¯e via inverse beta decay. The positron-neutron space and time coincidence allows for a sizable background rejection, nonetheless liquid scintillator detectors would

Is computer aided detection (CAD) cost effective in screening mammography? A model based on the CADET II study

PubMed Central

2011-01-01

Background Single reading with computer aided detection (CAD) is an alternative to double reading for detecting cancer in screening mammograms. The aim of this study is to investigate whether the use of a single reader with CAD is more cost-effective than double reading. Methods Based on data from the CADET II study, the cost-effectiveness of single reading with CAD versus double reading was measured in terms of cost per cancer detected. Cost (Pound (£), year 2007/08) of single reading with CAD versus double reading was estimated assuming a health and social service perspective and a 7 year time horizon. As the equipment cost varies according to the unit size a separate analysis was conducted for high, average and low volume screening units. One-way sensitivity analyses were performed by varying the reading time, equipment and assessment cost, recall rate and reader qualification. Results CAD is cost increasing for all sizes of screening unit. The introduction of CAD is cost-increasing compared to double reading because the cost of CAD equipment, staff training and the higher assessment cost associated with CAD are greater than the saving in reading costs. The introduction of single reading with CAD, in place of double reading, would produce an additional cost of £227 and £253 per 1,000 women screened in high and average volume units respectively. In low volume screening units, the high cost of purchasing the equipment will results in an additional cost of £590 per 1,000 women screened. One-way sensitivity analysis showed that the factors having the greatest effect on the cost-effectiveness of CAD with single reading compared with double reading were the reading time and the reader's professional qualification (radiologist versus advanced practitioner). Conclusions Without improvements in CAD effectiveness (e.g. a decrease in the recall rate) CAD is unlikely to be a cost effective alternative to double reading for mammography screening in UK. This study provides updated estimates of CAD costs in a full-field digital system and assessment cost for women who are re-called after initial screening. However, the model is highly sensitive to various parameters e.g. reading time, reader qualification, and equipment cost. PMID:21241473

Electrochemical immunosensor with NiAl-layered double hydroxide/graphene nanocomposites and hollow gold nanospheres double-assisted signal amplification.

PubMed

Qiao, Lu; Guo, Yemin; Sun, Xia; Jiao, Yancui; Wang, Xiangyou

2015-08-01

A sensitive electrochemical immunosensor based on NiAl-layered double hydroxide/graphene nanocomposites (NiAl-LDH/G) and hollow gold nanospheres (HGNs) was proposed for chlorpyrifos detection. The NiAl-LDH/G was prepared using a conventional coprecipitation process and reduction of the supporting graphene oxide. Subsequently, the nanocomposites were dispersed with chitosan (CS). The NiAl-LDH/G possessed good electrochemical behavior and high binding affinity to the electrode. The high surface areas of HGNs and the vast aminos and hydroxyls of CS provided a platform for the covalently crosslinking of antibody. Under optimal conditions, the immunosensor exhibited a wide linear range from 5 to 150 μg/mL and from 150 to 2 μg/mL, with a detection limit of 0.052 ng/mL. The detection results showed good agreement with standard gas chromatography method. The constructed immunosensor exhibited good reproducibility, high specificity, acceptable stability and regeneration performance, which provided a new promising tool for chlorpyrifos detection in real samples.

Erectile Dysfunction: MedlinePlus Health Topic

MedlinePlus

... Men's Health (Hormone Health Network) Also in Spanish Sex and the Man With Cancer (American Cancer Society) Also in Spanish Specifics Bent Penis (Mayo Foundation for Medical Education and Research) Videos and Tutorials Simultaneous Inflatable Penile Prosthesis (IPP) and ...

Connector For Embedded Optical Fiber

NASA Technical Reports Server (NTRS)

Wilkerson, Charles; Hiles, Steven; Houghton, J. Richard; Holland, Brent W.

1994-01-01

Partly embedded fixture is simpler and sturdier than other types of outlets for optical fibers embedded in solid structures. No need to align coupling prism and lenses. Fixture includes base, tube bent at 45 degree angle, and ceramic ferrule.

Spontaneous helix formation in non-chiral bent-core liquid crystals with fast linear electro-optic effect

PubMed Central

Sreenilayam, Sithara P.; Panarin, Yuri P.; Vij, Jagdish K.; Panov, Vitaly P.; Lehmann, Anne; Poppe, Marco; Prehm, Marko; Tschierske, Carsten

2016-01-01

Liquid crystals (LCs) represent one of the foundations of modern communication and photonic technologies. Present display technologies are based mainly on nematic LCs, which suffer from limited response time for use in active colour sequential displays and limited image grey scale. Herein we report the first observation of a spontaneously formed helix in a polar tilted smectic LC phase (SmC phase) of achiral bent-core (BC) molecules with the axis of helix lying parallel to the layer normal and a pitch much shorter than the optical wavelength. This new phase shows fast (∼30 μs) grey-scale switching due to the deformation of the helix by the electric field. Even more importantly, defect-free alignment is easily achieved for the first time for a BC mesogen, thus providing potential use in large-scale devices with fast linear and thresholdless electro-optical response. PMID:27156514

A study of Channeling, Volume Reflection and Volume Capture of 3.35 - 14.0 GeV Electrons in a bent Silicon Crystal

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

Wistisen, T. N.; Uggerhoj, U. I.; Wienands, U.

2015-12-03

We present the experimental data and analysis of experiments conducted at SLAC National Accelerator Laboratory investigating the processes of channeling, volume-reflection and volume-capture along the (111) plane in a strongly bent quasi-mosaic silicon crystal. Additionally, these phenomena were investigated at 5 energies: 3.35, 4.2, 6.3, 10.5 and 14.0 GeV with a crystal with bending radius of 0.15m, corresponding to curvatures of 0.070, 0.088, 0.13, 0.22 and 0.29 times the critical curvature respectively. We have extracted important parameters describing the channeling process such as the dechanneling length, the angle of volume reflection, the surface transmission and the widths of the distributionmore » of channeled particles parallel and orthogonal to the plane.« less

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

Bitter, M; Hill, K W; Scott, S

This paper consists of two parts: Part I describes the working principle of a recently developed x-ray imaging crystal spectrometer, where the astigmatism of spherically bent crystals is being used with advantage to record spatially resolved spectra of highly charged ions for Doppler measurements of the ion-temperature and toroidal plasmarotation- velocity profiles in tokamak plasmas. This type of spectrometer was thoroughly tested on NSTX and Alcator C-Mod, and its concept was recently adopted for the design of the ITER crystal spectrometers. Part II describes imaging schemes, where the astigmatism has been eliminated by the use of matched pairs of sphericallymore » bent crystals or reflectors. These imaging schemes are applicable over a wide range of the electromagnetic radiation, which includes microwaves, visible light, EUV radiation, and x-rays. Potential applications with EUV radiation and x-rays are the diagnosis of laserproduced plasmas, imaging of biological samples with synchrotron radiation, and lithography.« less

Further studies of propellant sloshing under low-gravity conditions

NASA Technical Reports Server (NTRS)

Dodge, F. T.

1971-01-01

A variational integral is formulated from Hamilton's Principle and is proved to be equivalent to the usual differential equations of low-gravity sloshing in ellipsoidal tanks. It is shown that for a zero-degree contact angle the contact line boundary condition corresponds to the stuck condition, a result that is due to the linearization of the equations and the ambiguity in the definition of the wave height at the wall. The variational integral is solved by a Rayleigh-Ritz technique. Results for slosh frequency when the free surface is not bent-over compare well with previous numerical solutions. When the free surface is bent over, however, the results for slosh frequency are considerably larger than those predicted by previous finite-difference, numerical approaches: the difference may be caused by the use of a zero degree contact angle in the present theory in contrast to the nonzero contact angle used in the numerical approaches.

Modeling Jupiter's current disc - Pioneer 10 outbound

NASA Astrophysics Data System (ADS)

Jones, D. E.; Melville, J. G.; Blake, M. L.

1980-07-01

A model of the magnetic field of the Jovian current disk is presented. The model uses Euler functions and the Biot-Savart law applied to a series of concentric, but not necessarily coplanar current rings. It was found that the best fit to the Pioneer 10 outbound perturbation magnetic field data is obtained if the current disk is twisted, and also bent to tend toward parallelism with the Jovigraphic equator. The inner and outer radii of the disk appear to be about 7 and 150 Jovian radii, respectively; because of the observed current disk penetrations, the bent disk also requires a deformation in the form of a bump or wrinkle whose axis tends to exhibit spiraling. Modeling of the azimuthal field shows that it is due to a thin radial current sheet, but it may actually be due in large part to penetration of a tail current sheet as suggested by Voyager observations.

Bending effects and temperature dependence of magnetic properties in a Fe-rich amorphous wire

NASA Astrophysics Data System (ADS)

Bordin, G.; Buttino, G.; Poppi, M.

2001-08-01

Amorphous wires with composition Fe 77.5Si 7.5B 15 exhibit a very peculiar magnetization process characterized by a single and quite large Barkhausen jump. This gives rise to a squared hysteresis loop at a critical magnetic field. The bistable behaviour, widely studied in wires with typical length of 10 cm and diameter of 125 μm, appears above a length of about 7 cm in straight wires and disappears for curvature radius within the range 2-12 cm in bent wires. In this work it is shown that bistability occurs in bent wires, whatever their curvature is, provided the wires are long enough. To this purpose spiral-shaped samples with several turns are considered. However, when the wire length is not a integer number of turns the magnetization reverses through many large Barkhausen jumps. In this condition, varying the measuring temperature can activate the energy barriers for the jumps.

Dual-wavelength nano-engineered Thulium-doped fiber laser via bending of singlemode-multimode-singlemode fiber structure

NASA Astrophysics Data System (ADS)

Zulkifli, A. Z.; Latiff, A. A.; Paul, M. C.; Yasin, M.; Ahmad, H.; Harun, S. W.

2016-12-01

In this paper, a dual-wavelength fiber laser (DWFL) using nano-engineered Thulium-doped fiber as a gain medium with a bent singlemode-multimode-singlemode fiber structure (SMS) is demonstrated. The SMS structure is packaged systematically using Cr-39 polymer plates to provide linear bending via applied load. Experimental results have proved that the bent SMS is capable to provide highly effective wavelength filter and wavelengths stabilizer by balancing the net cavity gain between the two wavelengths. The DWFL provides very narrow spacing of 0.9 nm, narrow 3 dB spectral linewidth of ∼0.07 nm and SNR of ∼42 dB. Based on stability test, very small mode hopping is observed at the two wavelengths having deviations of ±0 nm and ±0.04 nm respectively. In conjunction, the DWFL provides very stable relative wavelength spacing with a deviation of ±0.04 nm.

Heat-transfer distributions on biconics at incidence in hypersonic-hypervelocity He, N2, air, and CO2 flows

NASA Technical Reports Server (NTRS)

Miller, C. G.; Micol, J. R.; Gnoffo, P. A.; Wilder, S. E.

1983-01-01

Laminar heat transfer rates were measured on spherically blunted, 13 deg/7 deg on axis and bent biconics (fore cone bent 7 deg upward relative to aft cone) at hypersonic hypervelocity flow conditions in the Langley Expansion Tube. Freestream velocities from 4.5 to 6.9 km/sec and Mach numbers from 6 to 9 were generated using helium, nitrogen, air, and carbon dioxide test gases, resulting in normal shock density ratios from 4 to 19. Angle of attack, referenced to the axis of the aft cone, was varied from 0 to 20 deg in 4 deg increments. The effect of nose bend, angle of attack, and real gas phenomena on heating distributions are presented along with comparisons of measurement to prediction from a code which solves the three dimensional parabolized Navier-Stokes equations.

Quantum monodromy and quantum phase transitions in floppy molecules

NASA Astrophysics Data System (ADS)

Larese, Danielle

2012-10-01

A simple algebraic Hamiltonian has been used to explore the vibrational and rotational spectra of the skeletal bending modes of HCNO, BrCNO, NCNCS, and other "floppy" (quasi-linear or quasi-bent) molecules. These molecules have large-amplitude, low-energy bending modes and champagne-bottle potential surfaces, making them good candidates for observing quantum phase transitions (QPT). We describe the geometric phase transitions from bent to linear in these and other non-rigid molecules, quantitatively analyzing the spectroscopic signatures of ground state QPT, excited state QPT, and quantum monodromy. The algebraic framework is ideal for this work because of its small calculational effort yet robust results. Although these methods have historically found success with tri-and four-atomic molecules, we now address five-atomic and simple branched molecules such as CH3NCO and GeH3NCO. Extraction of potential functions are completed for several molecules, resulting in predictions of barriers to linearity and equilibrium bond angles.

Development of an instrumentation system for measurement of degradation of lubricating oil using optical fiber sensor

NASA Astrophysics Data System (ADS)

Laskar, S.; Bordoloi, S.

2016-01-01

This paper presents an instrumentation system to measure the degradation in lubricating oil using a bare, tapered and bent multi-mode optical fiber (BTBMOF) sensor probe and a temperature probe. The sensor system consists of (i) a bare, tapered and bent multi-mode optical fiber (BTBMOF) as optical sensor along with a laser source and a LDR (Light Dependent Resistor) as detector (ii) a temperature sensor (iii) a ATmega microcontroller based data acquisition system and (iv) a trained ANN for processing and calibration. The BTBMOF sensor and the temperature sensor are used to provide the measure of refractive index (RI) and the temperature of a lubricating oil sample. A microcontroller based instrumentation system with trained ANN algorithm has been developed to determine the degradation of the lubricating oil sample by sampling the readings of the optical fiber sensor, and the temperature sensor.

Standing helicon induced by a rapidly bent magnetic field in plasmas

NASA Astrophysics Data System (ADS)

Takahashi, Kazunori; Takayama, Sho; Komuro, Atsushi; Ando, Akira; Plasma physics Team

2016-09-01

An electron energy probability function and an rf magnetic field are measured in an rf hydrogen helicon source, where axial and transverse static magnetic fields are applied to the source by solenoids and to the diffusion chamber by filter magnets, respectively. It is demonstrated that the helicon wave is reflected by the rapidly bent magnetic field and the resultant standing wave heats the electrons between the source and the magnetic filter, while the electron cooling effect by the magnetic filter is maintained. It is interpreted that the standing wave is generated by the presence of spatially localized change of a refractive index. The application to the hydrogen negative ion source used for the neutral beam injection system for fusion plasma heating is discussed. This work is partially supported by grant-in-aid for scientific research (16H04084 and 26247096) from the Japan Society for the Promotion of Science.

An Optically Isotropic Antiferroelectric Liquid Crystal (OI-AFLC) Display Mode Operating over a Wide Temperature Range using Ternary Bent-Core Liquid Crystal Mixtures

DOE PAGES

Bergquist, Leah; Zhang, Cuiyu; Ribeiro de Almeida, Roberta R.; ...

2017-02-07

Here, we report on the synthesis and characterization of bent-core liquid crystal (LC) compounds and the preparation of mixtures that provide an optically isotropic antiferroelectric (OI-AFLC) liquid crystal display mode over a very wide temperature interval and well below room temperature. From the collection of compounds synthesized during this study, we recognized that several ternary mixtures displayed a modulated SmC aP A phase down to below -40 °C and up to about 100 °C on both heating and cooling, as well as optical tilt angles in the transformed state of approximately 45° (optically isotropic state). The materials were fully characterizedmore » and their liquid crystal as well as electro-optical properties analyzed by polarized optical microscopy, differential scanning calorimetry, synchrotron X-ray diffraction, dielectric spectroscopy, and electro-optical tests.« less

Monolithic photonic integrated circuit with a GaN-based bent waveguide

NASA Astrophysics Data System (ADS)

Cai, Wei; Qin, Chuan; Zhang, Shuai; Yuan, Jialei; Zhang, Fenghua; Wang, Yongjin

2018-06-01

Integration of a transmitter, waveguide and receiver into a single chip can generate a multicomponent system with multiple functionalities. Here, we fabricate and characterize a GaN-based photonic integrated circuit (PIC) on a GaN-on-silicon platform. With removal of the silicon and back wafer thinning of the epitaxial film, ultrathin membrane-type devices and highly confined suspended GaN waveguides were formed. Two suspended-membrane InGaN/GaN multiple-quantum-well diodes (MQW-diodes) served as an MQW light-emitting diode (MQW-LED) to emit light and an MQW photodiode (MQW-PD) to sense light. The optical interconnects between the MQW-LED and MQW-PD were achieved using the GaN bent waveguide. The GaN-based PIC consisting of an MQW-LED, waveguides and an MQW-PD forms an in-plane light communication system with a data transmission rate of 70 Mbps.

Spontaneous helix formation in non-chiral bent-core liquid crystals with fast linear electro-optic effect

NASA Astrophysics Data System (ADS)

Sreenilayam, Sithara P.; Panarin, Yuri P.; Vij, Jagdish K.; Panov, Vitaly P.; Lehmann, Anne; Poppe, Marco; Prehm, Marko; Tschierske, Carsten

2016-05-01

Liquid crystals (LCs) represent one of the foundations of modern communication and photonic technologies. Present display technologies are based mainly on nematic LCs, which suffer from limited response time for use in active colour sequential displays and limited image grey scale. Herein we report the first observation of a spontaneously formed helix in a polar tilted smectic LC phase (SmC phase) of achiral bent-core (BC) molecules with the axis of helix lying parallel to the layer normal and a pitch much shorter than the optical wavelength. This new phase shows fast (~30 μs) grey-scale switching due to the deformation of the helix by the electric field. Even more importantly, defect-free alignment is easily achieved for the first time for a BC mesogen, thus providing potential use in large-scale devices with fast linear and thresholdless electro-optical response.

The fourth Bent-toed Gecko of the genus Cyrtodactylus (Squamata: Gekkonidae) from Java, Indonesia.

PubMed

Riyanto, Awal; Grismer, L Lee; Wood, Perry L

2015-12-22

Cyrtodactylus petani sp. nov. is a new species of Bent-toed Gecko from Java, Indonesia that had been masquerading under the name C. fumosus (Müller, 1895). The new species is differentiated from C. fumosus and all its Sundaland congeners by having the following combination of morphological characters: a maximum SVL of 57.2 mm; nine or ten supralabials; seven or eight infralabials; strongly tuberculate body and limbs; 20-25 paravertebral tubercles; 30-35 ventral scales; enlarged precloacal scales; enlarged femoral scales; 17-18 subdigital lamellae on the fourth toe; 31-35 continuous precloacal and femoral pores in males, pores absent in females; no precloacal groove; no enlarged median subcaudals; tubercles on anterior portion of tail; no reticulated pattern on top of head; a blotched dorsal pattern; and no paired, dark, semi-lunar shaped blotches on the nape.

An Optically Isotropic Antiferroelectric Liquid Crystal (OI-AFLC) Display Mode Operating over a Wide Temperature Range using Ternary Bent-Core Liquid Crystal Mixtures

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

Bergquist, Leah; Zhang, Cuiyu; Ribeiro de Almeida, Roberta R.

Here, we report on the synthesis and characterization of bent-core liquid crystal (LC) compounds and the preparation of mixtures that provide an optically isotropic antiferroelectric (OI-AFLC) liquid crystal display mode over a very wide temperature interval and well below room temperature. From the collection of compounds synthesized during this study, we recognized that several ternary mixtures displayed a modulated SmC aP A phase down to below -40 °C and up to about 100 °C on both heating and cooling, as well as optical tilt angles in the transformed state of approximately 45° (optically isotropic state). The materials were fully characterizedmore » and their liquid crystal as well as electro-optical properties analyzed by polarized optical microscopy, differential scanning calorimetry, synchrotron X-ray diffraction, dielectric spectroscopy, and electro-optical tests.« less

A comparison of wire- and Kevlar-reinforced provisional restorations.

PubMed

Powell, D B; Nicholls, J I; Yuodelis, R A; Strygler, H

1994-01-01

Stainless steel wire 0.036 inch in diameter was compared with Kevlar 49 polyaramid fiber as a means of reinforcing a four-unit posterior provisional fixed restoration with 2 pontics. Three reinforcement patterns for wire and two for Kevlar 49 were evaluated and compared with the control, which was an unreinforced provisional restoration. A central tensile load was placed on the cemented provisional restoration and the variables were measured: (1) the initial stiffness; (2) the load at initial fracture; and (3) the unit toughness, or the energy stored in the beam at a point where the load had undergone a 1.0-mm deflection. Statistical analysis showed (1) the bent wire configuration had a significantly higher initial stiffness (P < or = .05), (2) there was no difference between designs for load at initial fracture, and (3) the bent wire had a significantly higher unit toughness value (P < or = .05).

Phase transitions in nanocomposites of hydrogen-bonded dimeric liquid crystals with mesogenic and non-mesogenic components

NASA Astrophysics Data System (ADS)

Katranchev, Boyko; Petrov, Minko

2016-02-01

Microtextural polarization, phase transitions, and electro-optical effects are studied in a series of nanocomposites, grown by mixing alkyloxybenzoic acids (nOBAs), displaying hydrogen-bonded dimeric liquid crystal (LC) state, with non-mesogens (single-walled carbon nanotubes (SWCNTs), perfluorooctanoic acid) or mesogens (bent-core LC compound D14F3). Each of the studied nanocomposites, in which the nOBA serves as a matrix, forms complexes with bent-shaped dimeric, caused by the interaction between the dopant structural units and the dimer rings. This feature, coordinated with the surface anchoring, bulk and electrical effects, leads to drastic reduction of the LC system symmetry. As a result, transitions from achiral (characteristic for the pristine nOBA) to chiral states (including ferroelectric smectic C with C2 symmetry and ferroelectric smectic CG with the lowest C1 triclinic one) take place. The functionalization of the SWCNTs causes drastic increase of the ferroelectricity.

Multi-spacecraft coherent Doppler and ranging for interplanetary-navigation

NASA Technical Reports Server (NTRS)

Pollmeier, Vincent M.

1995-01-01

Future plans for planetary exploration currently include using multiple spacecraft to simultaneously explore one planet. This never before encountered situation places new demands on tracking systems used to support navigation. One possible solution to the problem of heavy ground resource conflicts is the use of multispacecraft coherent radio metric data, also known as, bent-pipe data. Analysis of the information content of these data types show that the information content of multi-spacecraft Doppler is dependent only on the frequency of the final downlink leg and is independent of the frequencies used on other legs. Numerical analysis shows that coherent bent-pipe data can provide significantly better capability to estimate the location of a lander on the surface of Mars than can direct lander to Earth radio metric data. However, this is complicated by difficulties in separating the effect of a lander position error from that of an orbiter position error for single passes of data.

A novel C-shaped, gold nanoparticle coated, embedded polymer waveguide for localized surface plasmon resonance based detection.

PubMed

Prabhakar, Amit; Mukherji, Soumyo

2010-12-21

In this study, a novel embedded optical waveguide based sensor which utilizes localized surface plasmon resonance of gold nanoparticles coated on a C-shaped polymer waveguide is being reported. The sensor, as designed, can be used as an analysis chip for detection of minor variations in the refractive index of its microenvironment, which makes it suitable for wide scale use as an affinity biosensor. The C-shaped waveguide coupled with microfluidic channel was fabricated by single step patterning of SU8 on an oxidized silicon wafer. The absorbance due to the localized surface plasmon resonance (LSPR) of SU8 waveguide bound gold nano particle (GNP) was found to be linear with refractive index changes between 1.33 and 1.37. A GNP coated C-bent waveguide of 200 μ width with a bend radius of 1 mm gave rise to a sensitivity of ~5 ΔA/RIU at 530 nm as compared to the ~2.5 ΔA/RIU (refractive index units) of the same dimension bare C-bend SU8 waveguide. The resolution of the sensor probe was ~2 × 10(-4) RIU.

Vertical transmission of Prunus necrotic ringspot virus: hitch-hiking from gametes to seedling.

PubMed

Amari, Khalid; Burgos, Lorenzo; Pallás, Vicente; Sánchez-Pina, Maria Amelia

2009-07-01

The aim of this work was to follow Prunus necrotic ringspot virus (PNRSV) infection in apricot reproductive tissues and transmission of the virus to the next generation. For this, an analysis of viral distribution in apricot reproductive organs was carried out at different developmental stages. PNRSV was detected in reproductive tissues during gametogenesis. The virus was always present in the nucellus and, in some cases, in the embryo sac. Studies within infected seeds at the embryo globular stage revealed that PNRSV infects all parts of the seed, including embryo, endosperm and testa. In the torpedo and bent cotyledon developmental stages, high concentrations of the virus were detected in the testa and endosperm. At seed maturity, PNRSV accumulated slightly more in the embryo than in the cotyledons. In situ hybridization showed the presence of PNRSV RNA in embryos obtained following hand-pollination of virus-free pistils with infected pollen. Interestingly, tissue-printing from fruits obtained from these pistils showed viral RNA in the periphery of the fruits, whereas crosses between infected pistils and infected pollen resulted in a total invasion of the fruits. Taken together, these results shed light on the vertical transmission of PNRSV from gametes to seedlings.

[Spectral analysis of fiber bragg grating modulated by double long period grating and its application in smart structure monitoring].

PubMed

Lu, Ji-Yun; Liang, Da-Kai; Zhang, Xiao-Li; Zhu, Zhu

2009-12-01

Spectrum of fiber bragg grating (FBG) sensor modulated by double long period grating (LPFG) is proposed in the paper. Double LPFG consists of two LPFGS whose center wavelengths are the same and reflection spectrum of FBG sensor is located in linear range of double LPFG transmission spectrum. Based on spectral analysis of FBG and double LPFG, reflection spectrum of FBG modulated by double LPFG is obtained and studied by use of band-hider filter characteristics for double LPFG. An FBG sensor is attached on the surface of thin steel beam, which is strained by bending, and the center wavelength of FBG sensor will shift. The spectral peak of FBG sensor modulated by double LPFG is changed correspondingly, and the spectral change will lead to variation in exit light intensity from double LPFG. Experiment demonstrates that the relation of filtering light intensity from double LPFG monitored by optical power meter to center wavelength change of FBG sensor is linear and the minimum strain of material (steel beam) detected by the modulation and demodulation system is 1.05 microepsilon. This solution is used in impact monitoring of optical fibre smart structure, and FBG sensor is applied for impulse response signal monitoring induced by low-velocity impact, when impact pendulum is loaded to carbon fiber-reinforced plastics (CFP). The acquired impact response signal and fast Fourier transform of the signal detected by FBG sensor agree with the measurement results of eddy current displacement meter attached to the FBG sensor. From the results, the present method using FBG sensor is found to be effective for monitoring the impact. The research provides a practical reference in dynamic monitoring of optical fiber smart structure field.

Bend, stretch, and touch: Locating a finger on an actively deformed transparent sensor array

PubMed Central

Sarwar, Mirza Saquib; Dobashi, Yuta; Preston, Claire; Wyss, Justin K. M.; Mirabbasi, Shahriar; Madden, John David Wyndham

2017-01-01

The development of bendable, stretchable, and transparent touch sensors is an emerging technological goal in a variety of fields, including electronic skin, wearables, and flexible handheld devices. Although transparent tactile sensors based on metal mesh, carbon nanotubes, and silver nanowires demonstrate operation in bent configurations, we present a technology that extends the operation modes to the sensing of finger proximity including light touch during active bending and even stretching. This is accomplished using stretchable and ionically conductive hydrogel electrodes, which project electric field above the sensor to couple with and sense a finger. The polyacrylamide electrodes are embedded in silicone. These two widely available, low-cost, transparent materials are combined in a three-step manufacturing technique that is amenable to large-area fabrication. The approach is demonstrated using a proof-of-concept 4 × 4 cross-grid sensor array with a 5-mm pitch. The approach of a finger hovering a few centimeters above the array is readily detectable. Light touch produces a localized decrease in capacitance of 15%. The movement of a finger can be followed across the array, and the location of multiple fingers can be detected. Touch is detectable during bending and stretch, an important feature of any wearable device. The capacitive sensor design can be made more or less sensitive to bending by shifting it relative to the neutral axis. Ultimately, the approach is adaptable to the detection of proximity, touch, pressure, and even the conformation of the sensor surface. PMID:28345045

Bend, stretch, and touch: Locating a finger on an actively deformed transparent sensor array.

PubMed

Sarwar, Mirza Saquib; Dobashi, Yuta; Preston, Claire; Wyss, Justin K M; Mirabbasi, Shahriar; Madden, John David Wyndham

2017-03-01

The development of bendable, stretchable, and transparent touch sensors is an emerging technological goal in a variety of fields, including electronic skin, wearables, and flexible handheld devices. Although transparent tactile sensors based on metal mesh, carbon nanotubes, and silver nanowires demonstrate operation in bent configurations, we present a technology that extends the operation modes to the sensing of finger proximity including light touch during active bending and even stretching. This is accomplished using stretchable and ionically conductive hydrogel electrodes, which project electric field above the sensor to couple with and sense a finger. The polyacrylamide electrodes are embedded in silicone. These two widely available, low-cost, transparent materials are combined in a three-step manufacturing technique that is amenable to large-area fabrication. The approach is demonstrated using a proof-of-concept 4 × 4 cross-grid sensor array with a 5-mm pitch. The approach of a finger hovering a few centimeters above the array is readily detectable. Light touch produces a localized decrease in capacitance of 15%. The movement of a finger can be followed across the array, and the location of multiple fingers can be detected. Touch is detectable during bending and stretch, an important feature of any wearable device. The capacitive sensor design can be made more or less sensitive to bending by shifting it relative to the neutral axis. Ultimately, the approach is adaptable to the detection of proximity, touch, pressure, and even the conformation of the sensor surface.

Double hump sign in indentation gonioscopy is correlated with presence of plateau iris configuration regardless of patent iridotomy.

PubMed

Kiuchi, Yoshiaki; Kanamoto, Takashi; Nakamura, Takao

2009-02-01

A plateau iris is one of the clinical forms of angle closure glaucoma. In patients with a patent iridotomy, the double hump sign detected during indentation gonioscopy has been reported to indicate the existence of a plateau iris configuration. The purpose of this study was to determine whether the double hump sign is correlated with the presence of the plateau iris syndrome regardless of the patency of the iridotomy. Five women and 3 men without a patent iridotomy presented with narrow angles on gonioscopy and a double hump sign on indentation gonioscopy. Ultrasound biomicroscopy (UBM) imaging was performed to determine the etiology of the narrow angle and double hump sign, and to determine the appropriate treatment to prevent the progression of visual field damage. Ten patients with narrow angles and without a double hump sign were also examined by UBM to serve as a control group. All 8 patients who showed double hump sign had a short iris root, which was inserted anterior to the ciliary face, a typical anatomic appearance of a plateau iris. On the other hand, only 1 eye of 10 eyes in control group appeared to have a plateau iris. A double hump sign observed on indentation gonioscopy is strongly correlated with the presence of a plateau iris, and therefore a useful indicator of a plateau iris configuration regardless of the patency of a laser iridotomy. Thus, a plateau iris configuration can be detected without using a UBM in many cases.

Reliability and validity of three pain provocation tests used for the diagnosis of chronic proximal hamstring tendinopathy.

PubMed

Cacchio, Angelo; Borra, Fabrizio; Severini, Gabriele; Foglia, Andrea; Musarra, Frank; Taddio, Nicola; De Paulis, Fosco

2012-09-01

The clinical assessment of chronic proximal hamstring tendinopathy (PHT) in athletes is a challenge to sports medicine. To be able to compare the results of research and treatments, the methods used to diagnose and evaluate PHT must be clearly defined and reproducible. To assess the reliability and validity of three pain provocation tests used for the diagnosis of PHT. Ninety-two athletes with (N=46) and without (N=46) PHT were examined by one physician and two physiotherapists, who were trained in the examination techniques before the study. The examiners were blinded to the symptoms and identity of the athletes. The three pain provocation tests examined were the Puranen-Orava, bent-knee stretch and modified bent-knee stretch tests. Intraclass correlation coefficients (ICCs) based on the repeated measures analysis of variance were used to analyse the intraexaminer and interexaminer reliability, while sensitivity, specificity, predictive values and likelihood ratios were used to determine the validity of the three tests. The ICC values in all three tests revealed a high correlation (range 0.82 to 0.88) for the interexaminer reliability and a high-to-very high correlation (range 0.87 to 0.93) for the intraexaminer reliability. All three tests displayed a moderate-to-high validity, with the highest degree of validity being yielded by the modified bent-knee stretch test. All three pain provocation tests proved to be of potential value in assessing chronic PHT in athletes. However, we recommend that they be used in conjunction with other objective measures, such as MRI.

Surface integrity and fatigue behaviour of electric discharged machined and milled austenitic stainless steel

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

Lundberg, Mattias, E-mail: mattias.lundberg@liu.se

Machining of austenitic stainless steels can result in different surface integrities and different machining process parameters will have a great impact on the component fatigue life. Understanding how machining processes affect the cyclic behaviour and microstructure are of outmost importance in order to improve existing and new life estimation models. Milling and electrical discharge machining (EDM) have been used to manufacture rectangular four-point bend fatigue test samples; subjected to high cycle fatigue. Before fatigue testing, surface integrity characterisation of the two surface conditions was conducted using scanning electron microscopy, surface roughness, residual stress profiles, and hardness profiles. Differences in cyclicmore » behaviour were observed between the two surface conditions by the fatigue testing. The milled samples exhibited a fatigue limit. EDM samples did not show the same behaviour due to ratcheting. Recrystallized nano sized grains were identified at the severely plastically deformed surface of the milled samples. Large amounts of bent mechanical twins were observed ~ 5 μm below the surface. Grain shearing and subsequent grain rotation from milling bent the mechanical twins. EDM samples showed much less plastic deformation at the surface. Surface tensile residual stresses of ~ 500 MPa and ~ 200 MPa for the milled and EDM samples respectively were measured. - Highlights: •Milled samples exhibit fatigue behaviour, but not EDM samples. •Four-point bending is not suitable for materials exhibiting pronounced ratcheting. •LAGB density can be used to quantitatively measure plastic deformation. •Grain shearing and rotation result in bent mechanical twins. •Nano sized grains evolve due to the heat of the operation.« less

Self-assembly of tetravalent Goldberg polyhedra from 144 small components

NASA Astrophysics Data System (ADS)

Fujita, Daishi; Ueda, Yoshihiro; Sato, Sota; Mizuno, Nobuhiro; Kumasaka, Takashi; Fujita, Makoto

2016-12-01

Rational control of the self-assembly of large structures is one of the key challenges in chemistry, and is believed to become increasingly difficult and ultimately impossible as the number of components involved increases. So far, it has not been possible to design a self-assembled discrete molecule made up of more than 100 components. Such molecules—for example, spherical virus capsids—are prevalent in nature, which suggests that the difficulty in designing these very large self-assembled molecules is due to a lack of understanding of the underlying design principles. For example, the targeted assembly of a series of large spherical structures containing up to 30 palladium ions coordinated by up to 60 bent organic ligands was achieved by considering their topologies. Here we report the self-assembly of a spherical structure that also contains 30 palladium ions and 60 bent ligands, but belongs to a shape family that has not previously been observed experimentally. The new structure consists of a combination of 8 triangles and 24 squares, and has the symmetry of a tetravalent Goldberg polyhedron. Platonic and Archimedean solids have previously been prepared through self-assembly, as have trivalent Goldberg polyhedra, which occur naturally in the form of virus capsids and fullerenes. But tetravalent Goldberg polyhedra have not previously been reported at the molecular level, although their topologies have been predicted using graph theory. We use graph theory to predict the self-assembly of even larger tetravalent Goldberg polyhedra, which should be more stable, enabling another member of this polyhedron family to be assembled from 144 components: 48 palladium ions and 96 bent ligands.

1,2,4-oxadiazole-based bent-core liquid crystals with cybotactic nematic phases.

PubMed

Shanker, Govindaswamy; Prehm, Marko; Nagaraj, Mamatha; Vij, Jagdish K; Weyland, Marvin; Eremin, Alexey; Tschierske, Carsten

2014-05-19

Several series of bent-core mesogens derived from 3,5-diphenyl-1,2,4-oxadiazole with or without lateral groups and with different length terminal chains at both ends, and polycatenar molecules with three to six alkoxy chains are synthesized and their mesomorphic behaviour is investigated by polarizing microscopy, differential scanning calorimetry, X-ray diffraction (XRD), dielectric, electro-optical and second-harmonic generation (SHG) experiments. Most compounds exhibit broad regions of skewed cybotactic nematic (NcybC ) and tilted smectic (SmC) phases with a strong tilt of the aromatic cores (up to 63°), but non-tilted SmA and NcybA phases are also observed for a compound that has only one terminal chain. The XRD patterns of the nematic phases of most of the compounds investigated indicate a 2D periodicity with short correlation length in the magnetically aligned samples. This is of importance for the general interpretation of the small-angle XRD splitting patterns typically observed for aligned samples of bent-core nematic phases. In most nematic phases one current peak is observed in the half period of an applied electric field, though no coherent signal is found in the SHG experiments. Based on additional electro-optical and dielectric results, the nematic phases are considered to be cybotactic nematic phases with local polar order, and show a dielectric reorientation of the polar domains. Only chiral nematic phases (NcybC *), but not blue phases, are obtained for compounds with one or two chiral (3S)-3,7-dimethyloctyloxy tail(s). © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Monte Carlo N-Particle Tracking of Ultrafine Particle Flow in Bent Micro-Tubes

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

Casella, Andrew M.; Loyalka, Sudarsham K.

2016-02-16

The problem of large pressure-differential driven laminar convective-diffusive ultrafine aerosol flow through bent micro-tubes is of interest in several contemporary research areas including; release of contents from pressurized containment vessels, aerosol sampling equipment, advanced scientific instruments, gas-phase micro-heat exchangers, and microfluidic devices. In each of these areas, the predominant problem is the determination of the fraction of particles entering the micro-tube that is deposited within the tube and the fraction that is transmitted through. Due to the extensive parameter restrictions of this class of problems, a Lagrangian particle tracking method making use of the coupling of the analytical stream linemore » solutions of Dean and the simplified Langevin equation is quite a useful tool in problem characterization. This method is a direct analog to the Monte Carlo N-Particle method of particle transport extensively used in nuclear physics and engineering. In this work, 10 nm diameter particles with a density of 1 g/cm3 are tracked within micro-tubes with toroidal bends with pressure differentials ranging between 0.2175 and 0.87 atmospheres. The tubes have radii of 25 microns and 50 microns and the radius of curvature is between 1 m and 0.3183 cm. The carrier gas is helium, and temperatures of 298 K and 558 K are considered. Numerical convergence is considered as a function of time step size and of the number of particles per simulation. Particle transmission rates and deposition patterns within the bent micro-tubes are calculated.« less

Cyrtodactylus tahuna sp. nov., a new bent-toed gecko (Reptilia: Squamata: Gekkonidae) from Sangihe Island, North Sulawesi, Indonesia.

PubMed

Riyanto, Awal; Arida, Evy; Koch, AndrÉ

2018-03-21

Cyrtodactylus tahuna sp. nov. is a new bent-toed gecko we describe herein based on three specimens from Sangihe, North Sulawesi, Indonesia, an island situated in the northern corner of the Wallacea biodiversity hotspot. The new species is a medium sized Cyrtodactylus with a SVL of up to 78.5 mm in adult males and 79.2 mm in females. It is easily distinguished from all but four species (Cyrtodactylus fumosus, C. halmahericus, C. papuensis, and C. tambora) occurring on Sulawesi as well as in the Moluccas and the Lesser Sunda Islands, by possessing precloacal and femoral pores, enlarged precloacal and femoral scales, and lacking transversely enlarged median subcaudal scales. It differs from C. fumosus by the presence of tubercles on the ventrolateral fold, more unkeeled dorsal tubercles (19 versus 4-7) and a pit-like precloacal depression in males (versus groove in males); from C. halmahericus by presence of smaller scales between the enlarged precloacal and femoral scales (versus a continuous series of enlarged precloacofemoral scales) and a continuous series of precloacofemoral pores, as well as the presence of a pit-like precloacal depression in male (versus groove in males), from C. papuensis by possessing a pit-like precloacal depression in males (versus a groove ); and from C. tambora by the presence of tubercles on the dorsal surface of the brachium and the possession of femoral pores. Our contribution, along with several other recent descriptions of bent-toad geckos from Southeast Asia, clearly indicating that the diversity of the genus Cyrtodactylus in Indonesia is still underestimated.

Preparation and Characterization of Dabco (1,4-Diazabicyclo [2.2.2]octane) modified bentonite: Application for Congo red removal

NASA Astrophysics Data System (ADS)

Taher, Tarmizi; Rohendi, Dedi; Mohadi, Risfidian; Lesbani, Aldes

2018-01-01

Natural bentonite provided from Sarolangun deposit was modified with 1,4-Diazabicyclo[2.2.2]octane (Dabco) to form a new class of porous material. Prior further modification, the natural bentonite was cleaned up and activated by NaCl to remove the impurities and increase the bentonite nature. Dabco modified bentonite (Dabco-bent) was prepared by exchanging the inorganic cation placed in the interlayer space of the montmorillonite mineral structure with the 0.01 M Dabco1+ at pH 6. The modified bentonite products were characterized using X-Ray powder diffraction and FT-IR to monitor the change of the bentonite crystallinity and function group due to the modification process. The XRD result confirmed that during the modification process, the d(001) of smectite peak at 2q around 6° was shifted. After the modification, the d(001) reflection of the montmorillonite interlayer was shifted 0.36° to the left indicating that the interlayer space of the montmorillonite has been expanded during the modification process. The FTIR spectra of Dabco modified bentonite exhibit no significantly different with the host bentonite. However, the presence of the new band at the wavenumber around 3000 and 2800 cm-1 indicates that the Dabco molecule has been successfully inserted to the bentonite molecule. The Congo red adsorption experiment was performed onto Dabco-bent product by batch technique. The experiment data described that kinetic model for Congo red adsorption onto Dabco-bent was adequately followed the second-order kinetic model and well described by Freundlich adsorption isotherm model.

Dual chamber arrhythmia detection in the implantable cardioverter defibrillator.

PubMed

Dijkman, B; Wellens, H J

2000-10-01

Dual chamber implantable cardioverter defibrillator (ICD) technology extended ICD therapy to more than termination of hemodynamically unstable ventricular tachyarrhythmias. It created the basis for dual chamber arrhythmia management in which dependable detection is important for treatment and prevention of both ventricular and atrial arrhythmias. Dual chamber detection algorithms were investigated in two Medtronic dual chamber ICDs: the 7250 Jewel AF (33 patients) and the 7271 Gem DR (31 patients). Both ICDs use the same PR Logic algorithm to interpret tachycardia as ventricular tachycardia (VT), supraventricular tachycardia (SVT), or dual (VT+ SVT). The accuracy of dual chamber detection was studied in 310 of 1,367 spontaneously occurring tachycardias in which rate criterion only was not sufficient for arrhythmia diagnosis. In 78 episodes there was a double tachycardia, in 223 episodes SVT was detected in the VT or ventricular fibrillation zone, and in 9 episodes arrhythmia was detected outside the boundaries of the PR Logic functioning. In 100% of double tachycardias the VT was correctly diagnosed and received priority treatment. SVT was seen in 59 (19%) episodes diagnosed as VT. The causes of inappropriate detection were (1) algorithm failure (inability to fulfill the PR

Imaging voids beneath bridge bent using electrical resistivity tomography.

DOT National Transportation Integrated Search

2014-02-01

Five electrical resistivity tomography (ERT) profiles and borehole control were acquired beneath two bridges on the bank of the : Gasconade River in order to determine extension of the underground water-filled openings in rock encountered during a dr...

15. View to northeast. View along centerline from below deck; ...

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

15. View to northeast. View along centerline from below deck; detail of bent and floor beams. (65mm lens) - South Fork Trinity River Bridge, State Highway 299 spanning South Fork Trinity River, Salyer, Trinity County, CA

49 CFR 213.119 - Continuous welded rail (CWR); plan contents.

Code of Federal Regulations, 2010 CFR

2010-10-01

... following items: (i) Loose, bent, or missing joint bolts; (ii) Rail end batter or mismatch that contributes... amount and length of rail end batter or ramp on each rail end; the amount of tread mismatch; the vertical...

49 CFR 213.119 - Continuous welded rail (CWR); plan contents.

Code of Federal Regulations, 2011 CFR

2011-10-01

... following items: (i) Loose, bent, or missing joint bolts; (ii) Rail end batter or mismatch that contributes... amount and length of rail end batter or ramp on each rail end; the amount of tread mismatch; the vertical...

Hydraulic forces on submerged bridge decks.

DOT National Transportation Integrated Search

2008-09-01

Bridge decks can be subjected to large horizontal forces when overtopping occurs. These forces may result in the displacement of bridge decks from the bents. This paper reports on the results of a laboratory study of horizontal forces on bridge decks...

Research notes : capacity of aging bent caps.

DOT National Transportation Integrated Search

2008-10-01

Many conventionally reinforced concrete deck girder (RCDG) bridges were built in the United States during the construction of the interstate highway system in the 1950s. Designs followed the AASHO standard of the time, which were less stringent than ...

Visualizing Bent Bonds in Cyclopropane

ERIC Educational Resources Information Center

Bertolini, Thomas M.

2004-01-01

A two-minute overhead demonstration using a molecular model kit is employed for illustrating the unique binding of cyclopropane. It is reported that most model kits, much like an sp (super 3) hybridized carbon atom, resist forming 60-degree bond angles.

Isothermal amplification detection of nucleic acids by a double-nicked beacon.

PubMed

Shi, Chao; Zhou, Meiling; Pan, Mei; Zhong, Guilin; Ma, Cuiping

2016-03-01

Isothermal and rapid amplification detection of nucleic acids is an important technology in environmental monitoring, foodborne pathogen detection, and point-of-care clinical diagnostics. Here we have developed a novel method of isothermal signal amplification for single-stranded DNA (ssDNA) detection. The ssDNA target could be used as an initiator, coupled with a double-nicked molecular beacon, to originate amplification cycles, achieving cascade signal amplification. In addition, the method showed good specificity and strong anti-jamming capability. Overall, it is a one-pot and isothermal strand displacement amplification method without the requirement of a stepwise procedure, which greatly simplifies the experimental procedure and decreases the probability of contamination of samples. With its advantages, the method would be very useful to detect nucleic acids in point-of-care or field use. Copyright © 2015 Elsevier Inc. All rights reserved.

3D Printed Scintillators For Use in Field Emission Detection and Other Nuclear Physics Experiments

NASA Astrophysics Data System (ADS)

Ficenec, Karen

2015-10-01

In accelerator cavities, field emission electrons - electrons that get stripped away from the cavity walls due to the high electromagnetic field necessary to accelerate the main beam - are partially accelerated and can crash into the cavity walls, adding to the heat-load of the cryogenic system. Because these field electrons emit gamma rays when bent by the electromagnetic field, a scintillator, if made to fit the cavity enclosure, can detect their presence. Eliminating the waste of subtractive manufacturing techniques and allowing for the production of unique, varied shapes, 3D printing of scintillators may allow for an efficient detection system. UV light is used to start a chemical polymerization process that links the monomers of the liquid resin together into larger, intertwined molecules, forming the solid structure. Each shape requires slightly different calibration of its optimal printing parameters, such as slice thickness and exposure time to UV light. Thus far, calibration parameters have been optimized for cylinders of 20 mm diameter, cones of 30 mm diameter and 30 mm height, rectangular prisms 30 by 40 by 10 mm, and square pyramids 20 mm across. Calibration continues on creating holes in the prints (for optical fibers), as well as shapes with overhangs. Scintill This work was supported in part by the National Science Foundation under Grant No. PHY-1405857.

Landslide: Systematic Dynamic Race Detection in Kernel Space

DTIC Science & Technology

2012-05-01

schedule_in_flight← true; CAUSE_TIMER_INTERRUPT(); end if end function Thread Scheduling Finally, the Landslide scheduler is responsible for managing ...child process vanish() simultaneously. • double_wait: Tests interactions of multiple waiters on a single child. • double_thread_fork: Tests for...conditions using Landslide. We describe them here. • Too many waiters allowed. Using the double_wait test case, Group 1 found a bug in which more threads

Laser Energy Monitor for Double-Pulsed 2-Micrometer IPDA Lidar Application

NASA Technical Reports Server (NTRS)

Refaat, Tamer F.; Petros, Mulugeta; Remus, Ruben; Yu, Jirong; Singh, Upendra N.

2014-01-01

Integrated path differential absorption (IPDA) lidar is a remote sensing technique for monitoring different atmospheric species. The technique relies on wavelength differentiation between strong and weak absorbing features normalized to the transmitted energy. 2-micron double-pulsed IPDA lidar is best suited for atmospheric carbon dioxide measurements. In such case, the transmitter produces two successive laser pulses separated by short interval (200 microseconds), with low repetition rate (10Hz). Conventional laser energy monitors, based on thermal detectors, are suitable for low repetition rate single pulse lasers. Due to the short pulse interval in double-pulsed lasers, thermal energy monitors underestimate the total transmitted energy. This leads to measurement biases and errors in double-pulsed IPDA technique. The design and calibration of a 2-micron double-pulse laser energy monitor is presented. The design is based on a high-speed, extended range InGaAs pin quantum detectors suitable for separating the two pulse events. Pulse integration is applied for converting the detected pulse power into energy. Results are compared to a photo-electro-magnetic (PEM) detector for impulse response verification. Calibration included comparing the three detection technologies in single-pulsed mode, then comparing the pin and PEM detectors in double-pulsed mode. Energy monitor linearity will be addressed.

Temperature dependence of the low- and high-frequency Raman scattering from liquid water

NASA Astrophysics Data System (ADS)

Walrafen, G. E.; Fisher, M. R.; Hokmabadi, M. S.; Yang, W.-H.

1986-12-01

Low frequency Δν¯=0-350 cm-1, Raman intensity data were obtained from liquid water between 3.5 and 89.3 °C using holographic grating double and triple monochromators. The spectra were Bose-Einstein (BE) corrected, I/(1+n), and the total integrated (absolute) contour intensities were treated by an elaboration of the Young-Westerdahl (YW) thermodynamic method, assuming conservation of hydrogen-bonded (HB) and nonhydrogen-bonded (NHB=bent and/or stretched, O-H O) nearest-neighbor O-O pairs. A ΔH°1 value of 2.6±0.1 kcal/mol O-H ṡṡṡ O or 5.2±0.2 kcal/mol H2O (11 kJ/mol O-H ṡṡṡ O, or 22 kJ/mol H2O) resulted for the HB→NHB process. This intermolecular value agrees quantitatively with Raman and infrared ΔH° values from the one- and two-phonon OH-stretching regions, and from molecular dynamics, depolarized light scattering, neutron scattering, and ultrasonic absorption, thus indicating a common process. A population involving partial covalency of, i.e., charge transfer into, the H ṡṡṡ O units of linear and/or weakly bent hydrogen bonds, O-H ṡṡṡ O; is transformed into a second high energy population involving bent, e.g., 150° or less, and/or stretched, e.g., 3.2 Å, but otherwise strongly cohesive O-H O interactions. All difference spectra from the fundamental OH-stretching contours cross at the X(Z,X+Z)Y isobestic frequency of 3425 cm-1. Also, total integrated Raman intensity decreases occurring below 3425 cm-1 with temperature rise were found to be proportional to the total integrated intensity increases above 3425 cm-1, indicating conservation among the HB and NHB OH-stretching classes. From the enthalpy of vaporization of water at 0 °C, and the ΔH°1 of 2.6 kcal/mol O-H ṡṡṡ O, the additional enthalpy, ΔH°2, needed for the complete separation of the NHB O-O nearest neighbors is ˜3.2 kcal/mol O-H ṡṡṡ O or ˜6.4 kcal/mol H2O (13 kJ/mol O-H ṡṡṡ O or 27 kJ/mol H2O). The NHB O-O nearest neighbors are held by forces other than those involving H ṡṡṡ O partial covalency, i.e., electrostatic (multipole), induction, and dispersion forces. The NHB O-O pairs do not appear to produce significant intermolecular Raman intensity because they lack H ṡṡṡO bond polarizability, but the corresponding NHB OH oscillators do contribute weakened Raman intensity above 3425 cm-1. An ideal solution thermodynamic treatment employing ΔH°1 =2.6 kcal/mol O-H ṡṡṡ O, the HB mole fraction, and the vapor heat capacity, yielded a very satisfactory specific heat value of 1.1 cal deg-1 g-1 H2O at 0 °C. The NHB mole fraction, fu, from the YW treatment is negligibly small, 0.06 or less, for t<-50 °C. However, fu increases to 0.16 at 0 °C, and fu≊1 at 1437 °C, where recent shock-wave Raman measurements indicate loss of all partially covalent, charge transfer hydrogen bonding.

Patterns and conformations in molecularly thin films

NASA Astrophysics Data System (ADS)

Basnet, Prem B.

Molecularly thin films have been a subject of great interest for the last several years because of their large variety of industrial applications ranging from micro-electronics to bio-medicine. Additionally, molecularly thin films can be used as good models for biomembrane and other systems where surfaces are critical. Many different kinds of molecules can make stable films. My research has considered three such molecules: a polymerizable phospholipid, a bent-core molecules, and a polymer. One common theme of these three molecules is chirality. The phospolipid molecules studied here are strongly chiral, which can be due to intrinsically chiral centers on the molecules and also due to chiral conformations. We find that these molecules give rise to chiral patterns. Bent-core molecules are not intrinsically chiral, but individual molecules and groups of molecules can show chiral structures, which can be changed by surface interactions. One major, unconfirmed hypothesis for the polymer conformation at surface is that it forms helices, which would be chiral. Most experiments were carried out at the air/water interface, in what are called Langmuir films. Our major tools for studying these films are Brewster Angle Microscopy (BAM) coupled with the thermodynamic information that can be deduced from surface pressure isotherms. Phospholipids are one of the important constituents of liposomes -- a spherical vesicle com-posed of a bilayer membrane, typically composed of a phospholipid and cholesterol bilayer. The application of liposomes in drug delivery is well-known. Crumpling of vesicles of polymerizable phospholipids has been observed. With BAM, on Langmuir films of such phospholipids, we see novel spiral/target patterns during compression. We have found that both the patterns and the critical pressure at which they formed depend on temperature (below the transition to a i¬‘uid layer). Bent-core liquid crystals, sometimes knows as banana liquid crystals, have drawn increasing attention because of the richness in phases that they exhibit. Due to the unique coupling between dipole properties and the packing constraints placed by the bent shape, these molecules are emerging as strong candidates in electromechanical devices. However, most applications require that the molecules be aligned, which has proved difficult. Our group has tested such molecules both as Langmuir layers and, when transferred to a solid, as alignment layers with some limited success. However, these molecules do not behave well with the surfaces and the domains at the air/water interface tend to form ill-controlled multilayer structures since attraction with the surfaces is relatively weak. New bent-core molecules obtained from Prof. Dr. C. Tsehiemke from Department of Chemistry Institute of Organic Chemistry, Martin-Luther-University, Germany, have a hydrophilic group at one end. We expect this molecule to behave better on the surface because of the stronger attraction of the hydrophilic group towards the surface than for the bent-core molecules without the hydrophilic group. Polydimethylsiloxane (PDMS) is a polymer which finds many applications in modifying surface properties. It is used in manufacturing lubricants, protective coatings, hair conditioner and glass-coating. However its properties are not well understood. This polymer has been proposed to follow either helical or caterpillar conformations on a surface. The orientational order of CH3 side groups can test for these conformations (they would be predominantly up/down for the caterpillar conformation, but rotating through the entire 360 degree for the helical one). Thus previous work on the Langmuir polymer films at the air/water interface were complemented by deuterium NMR studies to probe their conformations at a surface. These experiments were performed using humid porous solids, in order to provide sufficient surface area for the technique. Previous tests in this group at room temperature were suggestive but inconclusive because of the rapid averaging motion of the molecules. Here, we attempt to freeze the molecules on the surface.

Detection of DNA double-strand breaks and chromosome translocations using ligation-mediated PCR and inverse PCR.

PubMed

Villalobos, Michael J; Betti, Christopher J; Vaughan, Andrew T M

2006-01-01

Current techniques for examining the global creation and repair of DNA double-strand breaks are restricted in their sensitivity, and such techniques mask any site-dependent variations in breakage and repair rate or fidelity. We present here a system for analyzing the fate of documented DNA breaks, using the MLL gene as an example, through application of ligation-mediated PCR. Here, a simple asymmetric double-stranded DNA adapter molecule is ligated to experimentally induced DNA breaks and subjected to seminested PCR using adapter and gene-specific primers. The rate of appearance and loss of specific PCR products allows detection of both the break and its repair. Using the additional technique of inverse PCR, the presence of misrepaired products (translocations) can be detected at the same site, providing information on the fidelity of the ligation reaction in intact cells. Such techniques may be adapted for the analysis of DNA breaks introduced into any identifiable genomic location.

An electrochemical biosensor for double-stranded Wnt7B gene detection based on enzymatic isothermal amplification.

PubMed

Li, Junlong; Chen, Zhongping; Xiang, Yu; Zhou, Lili; Wang, Ting; Zhang, Zhang; Sun, Kexin; Yin, Dan; Li, Yi; Xie, Guoming

2016-12-15

Wnt7B gene plays an important role in the development and progression of breast cancer, gastric cancer, esophageal cancer and pancreatic cancer. While, the natural state of DNA is double stranded, which makes it difficult to be directly detected. Here, we develop an electrochemical biosensor method for Wnt7B gene detection without the need to denature the target. This method firstly used nicking enzyme for exploiting in the double-stranded DNA (dsDNA). Then, long single-stranded DNA (ssDNA) was generated from the cutting site through polymerase extension reaction. Whereafter, the long ssDNA triggered a hairpin self-assembly recycling reaction, which gave rise to another isothermal amplification reaction. Last, short ssDNA was formed after the this amplification process, which could hybridize with the capture probe immobilized on Au electrode and result in signal variation. This method showed excellent analytical performance for dsDNA, of which the linear range was 2fM to 500pM and the detection limit was 1.6fM (S/N=3). It also showed an good results when applied to the real sample of Wnt7B gene detection. Copyright © 2016 Elsevier B.V. All rights reserved.

Double sampling to estimate density and population trends in birds

USGS Publications Warehouse

Bart, Jonathan; Earnst, Susan L.

2002-01-01

We present a method for estimating density of nesting birds based on double sampling. The approach involves surveying a large sample of plots using a rapid method such as uncorrected point counts, variable circular plot counts, or the recently suggested double-observer method. A subsample of those plots is also surveyed using intensive methods to determine actual density. The ratio of the mean count on those plots (using the rapid method) to the mean actual density (as determined by the intensive searches) is used to adjust results from the rapid method. The approach works well when results from the rapid method are highly correlated with actual density. We illustrate the method with three years of shorebird surveys from the tundra in northern Alaska. In the rapid method, surveyors covered ~10 ha h-1 and surveyed each plot a single time. The intensive surveys involved three thorough searches, required ~3 h ha-1, and took 20% of the study effort. Surveyors using the rapid method detected an average of 79% of birds present. That detection ratio was used to convert the index obtained in the rapid method into an essentially unbiased estimate of density. Trends estimated from several years of data would also be essentially unbiased. Other advantages of double sampling are that (1) the rapid method can be changed as new methods become available, (2) domains can be compared even if detection rates differ, (3) total population size can be estimated, and (4) valuable ancillary information (e.g. nest success) can be obtained on intensive plots with little additional effort. We suggest that double sampling be used to test the assumption that rapid methods, such as variable circular plot and double-observer methods, yield density estimates that are essentially unbiased. The feasibility of implementing double sampling in a range of habitats needs to be evaluated.

Prevention: Exercise

MedlinePlus

... hips and knees bent. Use your hips to push your body back to a standing position, then extend your arms ... your temple and use your neck muscles to push against your palm, holding for ... neck muscles to press back into your hands. Hold for ten seconds, and ...

Penis Fracture: Is It Possible?

MedlinePlus

... occur due to aggressive masturbation or taqaandan, a cultural practice in which the top of an erect penis is forcefully bent. A penis fracture is a painful injury. Signs might include a cracking sound, immediate loss of the erection, or the development of dark ...

Out of Flexland: The Third and Last of Mr. Flexman's Twisty Tours.

ERIC Educational Resources Information Center

Dubrovsky, Vladimir

1992-01-01

Discusses flexible polyhedrons, called flexors, that can be bent so that the faces stay rigid while the angles between them seem to change. Presents models representing flexors and directions on how examples can be constructed. (MDH)

Cybersecurity Update

DTIC Science & Technology

2014-01-23

was broken, the willow bent when it must and survived." Robert Jordan, The Fires of Heaven CERT I Software Engineering Institute I...transfer-of-wealth-in-history-7000000598/ 8.  Caralli, Richard A.; Allen, Julia H.; White , David W. CERT® Resilience Management Model: A Maturity

17. VIEW OF SETTLING BASIN, SHOWING FLUME TRACK SPUR CROSSING ...

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

17. VIEW OF SETTLING BASIN, SHOWING FLUME TRACK SPUR CROSSING OVER SETTLING BASIN, SPARE BENT MATERIAL IN RIGHT-HAND FOREGROUND, BYPASS FLUME, AND SHACK #6 IN BACKGROUND, LOOKING NORTHWEST - Electron Hydroelectric Project, Along Puyallup River, Electron, Pierce County, WA

Continuity diaphragm for skewed continuous span precast prestressed concrete girder bridges.

DOT National Transportation Integrated Search

2004-10-01

Continuity diaphragms used on skewed bents in prestressed girder bridges cause difficulties in detailing and : construction. Details for bridges with large diaphragm skew angles (>30) have not been a problem for LA DOTD. : However, as the skew angl...

Making pro formas perform.

PubMed

Bryan, Stephen; Lilien, Steven

2003-10-01

Regulators are trying to clear up the muddle created by earnings-report adjustments called "pro formas" that companies issue. Constraining such reporting, as the regulators seem bent on doing, isn't the solution. Firms should increase alternative reporting--and fully account for their accounting.

Evaluation of Cathodic Protection Systems for Marine Bridge Substructures

DOT National Transportation Integrated Search

1998-12-01

Four different cathodic protection systems were installed and evaluated in the reinforced concrete tie beams and footings of four bents at the Queen Isabella Causeway which links South Padre Island to the mainland of Texas. The types of cathodic prot...

Evaluation of immunity to varicella zoster virus with a novel double antigen sandwich enzyme-linked immunosorbent assay.

PubMed

Liu, Jian; Chen, Chunye; Zhu, Rui; Ye, Xiangzhong; Jia, Jizong; Yang, Lianwei; Wang, Yongmei; Wang, Wei; Ye, Jianghui; Li, Yimin; Zhu, Hua; Zhao, Qinjian; Zhang, Jun; Cheng, Tong; Xia, Ningshao

2016-11-01

Varicella is a highly contagious disease caused by primary infection of Varicella zoster virus (VZV). Varicella can be severe or even lethal in susceptible adults, immunocompromised patients and neonates. Determination of the status of immunity to VZV is recommended for these high-risk populations. Furthermore, measurement of population immunity to VZV can help in developing proper varicella vaccination programmes. VZV glycoprotein E (gE) is an antigen that has been demonstrated to be a highly accurate indicator of VZV-specific immunity. In this study, recombinant gE (rgE) was used to establish a double antigen sandwich enzyme-linked immunosorbent assay (ELISA). The established sandwich ELISA showed high specificity and sensitivity in the detection of human sera, and it could detect VZV-specific antibodies at a concentration of 11.25 m IU/mL with a detection linearity interval of 11.25 to 360 m IU/mL (R 2  = 0.9985). The double gE antigen sandwich ELISA showed a sensitivity of 95.08 % and specificity of 100 % compared to the fluorescent-antibody-to-membrane-antigen (FAMA) test, and it showed a sensitivity of 100 % and a specificity of 94.74 % compared to a commercial neutralizing antibody detection kit. Thus, the established double antigen sandwich ELISA can be used as a sensitive and specific quantitative method to evaluate immunity to VZV.

LCDRS FLOW FROM DOUBLE-LINED LANDFILLS AND SURFACE IMPOUNDMENTS

EPA Science Inventory

This report presents field data on the measured flows of liquid from the leakage detection, collection, and removal systems (LDCRSs) of 28 double-lined surface impoundment facilities. or each facility, information on design and operation is presented, as is an evaluation of the s...

Detecting gradual visual changes in colour and brightness agnosia: a double dissociation.

PubMed

Nijboer, Tanja C W; te Pas, Susan F; van der Smagt, Maarten J

2011-03-09

Two patients, one with colour agnosia and one with brightness agnosia, performed a task that required the detection of gradual temporal changes in colour and brightness. The results for these patients, who showed anaverage or an above-average performance on several tasks designed to test low-level colour and luminance (contrast) perception in the spatial domain, yielded a double dissociation; the brightness agnosic patient was within the normal range for the coloured stimuli, but much slower to detect brightness differences, whereas the colour agnosic patient was within the normal range for the achromatic stimuli, but much slower for the coloured stimuli. These results suggest that a modality-specific impairment in the detection of gradual temporal changes might be related to, if not underlie, the phenomenon of visual agnosia.

Comparison of gravimetric and a double-indicator dilution technique for assessment of extra-vascular lung water in endotoxaemia.

PubMed

Rossi, P; Oldner, A; Wanecek, M; Leksell, L G; Rudehill, A; Konrad, D; Weitzberg, E

2003-03-01

To compare a molecular double-indicator dilution technique with the gravimetrical reference method for measurement of extra-vascular lung water in porcine endotoxin shock. Open comparative experimental study. Animal research laboratory. In fourteen anaesthetised, mechanically ventilated landrace pigs, central and pulmonary haemodynamics as well as pulmonary gas exchange were measured. Extra-vascular lung water was quantitated gravimetrically as well as with a molecular double indicator dilution technique. Eight of these animals were subjected to endotoxaemia, the rest serving as sham controls. No difference in extra-vascular lung water was observed between the two methods in sham animals. Furthermore, extra-vascular lung water assessed with the molecular double-indicator dilution technique at the initiation of endotoxin infusion did not differ significantly from the corresponding values for sham animals. Endotoxaemia induced a hypodynamic shock with concurrent pulmonary hypertension and a pronounced deterioration in gas exchange. No increase in extra-vascular lung water was detected with the molecular double-indicator dilution technique in response to endotoxin, whereas this parameter was significantly higher when assessed with the gravimetric method. The molecular double-indicator dilution technique showed similar results as the gravimetrical method for assessment of extra-vascular lung water in non-endotoxaemic conditions. However, during endotoxin-induced lung injury the molecular double indicator dilution technique failed to detect the significant increase in extra-vascular lung water as measured by the gravimetric method. These data suggest that the molecular double indicator dilution technique may be of limited value during sepsis-induced lung injury.

[The risk of surgical glove perforations].

PubMed

Hagen, Gerd Ødegård; Arntzen, Halvard

2007-03-29

The increasing prevalence of blood-borne viral diseases has drawn attention to the barrier between the surgical personnel's hands and the patients body fluids during surgery. At present, the typical practice is to use double gloving in orthopaedic surgery, and single gloving in other types of surgery. The main purpose of our study was to estimate and compare the perforation risk in different categories of surgery. In a series of 655 surgical operations covering 5 main categories of surgery, all detected glove perforations were recorded and analysed. Perforations were found in 203 out of 655 operations (31%). The observed perforation frequency was 44.5% in gastrointestinal surgery, 34.7% in orthopaedic surgery, 31.1% in gynaecology, 18.6% in vascular surgery and 9.2% in general surgery. In some subcategories, the frequencies were even higher. In several categories of surgery, we found high perforation frequencies. Perforations in single gloves are often not detected during operations. This may increase the risk of transmission of blood-borne infections, particularly because the time of exposure may be long. Double indicator gloves make the intra-operative detection of perforations easier. Also double gloving is known to significantly reduce the perforation risk. The use of double indicator gloves is recommended in all categories of surgery.

Scintillating fibres coupled to silicon photomultiplier prototypes for fast beam monitoring and thin timing detectors

NASA Astrophysics Data System (ADS)

Papa, A.; Kettle, P.-R.; Ripiccini, E.; Rutar, G.

2016-07-01

Several scintillating fibre prototypes (single- and double-layers) made of 250 μm multi-clad square fibres coupled to silicon photomultiplier have been studied using electrons, positrons and muons at different energies. Current measurements show promising results: already for a single fibre layer and minimum ionizing particles we obtain a detection efficiency ≥ 95 % (mean collected light/fibre ≈ 8 phe), a timing resolution of 550 ps/fibre and a foreseen spatial resolution < 100 μm, based on the achieved negligible optical cross-talk between fibres (< 1 %). We will also discuss the performances of a double-layer staggered prototype configuration, for which a full detection efficiency (≥ 99 %) has been measured together with a timing resolution of ≈ 400 ps for double hit events.

A double-taper optical fiber-based radiation wave other than evanescent wave in all-fiber immunofluorescence biosensor for quantitative detection of Escherichia coli O157:H7.

PubMed

Zhang, Zhonghuan; Hua, Fei; Liu, Ting; Zhao, Yong; Li, Jun; Yang, Ruifu; Yang, Changxi; Zhou, Lei

2014-01-01

Cylindrical or taper-and-cylinder combination optical fiber probe based on evanescent wave has been widely used for immunofluorescence biosensor to detect various analytes. In this study, in contrast to the contradiction between penetration depth and analyte diameter of optical fiber probe-based evanescent wave, we demonstrate that double-taper optical fiber used in a radiation wave-based all-fiber immunofluorescence biosensor (RWAIB) can detect micron-scale analytes using Escherichia coli O157:H7 as representative target. Finite-difference time-domain method was used to compare the properties of evanescent wave and radiation wave (RW). Ray-tracing model was formulated to optimize the taper geometry of the probe. Based on a commercial multi-mode fiber, a double-taper probe was fabricated and connected with biosensor through a "ferrule connector" optical fiber connector. The RWAIB configuration was accomplished using commercial multi-mode fibers and fiber-based devices according to the "all-fiber" method. The standard sample tests revealed that the sensitivity of the proposed technique for E. coli O157:H7 detection was 10(3) cfu · mL(-1). Quantitation could be achieved within the concentration range of 10(3) cfu · mL(-1) to 107 cfu · mL(-1). No non-specific recognition to ten kinds of food-borne pathogens was observed. The results demonstrated that based on the double-taper optical fiber RWAIB can be used for the quantitative detection of micron-scale targets, and RW sensing is an alternative for traditional evanescent wave sensing during the fabrication of fiber-optic biosensors.

Development of a sensitive enzyme-linked immunosorbent assay for the measurement of biologically active etanercept in patients with ankylosing spondylitis.

PubMed

Wang, Lei; Wang, Xiaoxia; Li, Ying; Cheng, Zeneng

2016-01-01

Etanercept is the first tumor necrosis factor inhibitor to be approved for rheumatic disease treatment. Its in vivo concentration is usually detected with commercial enzyme-linked immunosorbent assay (ELISA) kits; specifically, previous researchers have mostly used double-antibody sandwich ELISA technology. Double-antibody sandwich ELISA is employed to detect the total etanercept rather than biologically active etanercept, which is more relevant in terms of therapeutic drug monitoring. In this work, a sensitive ELISA that employed its antigen TNF-α to capture biologically active etanercept for concentration detection was established and validated for etanercept pharmacokinetic (PK) study in patients with ankylosing spondylitis (AS). The proposed assay was demonstrated to be precise and accurate over the linear range of 12.5-400pg/mL. The intra- and inter-assay relative standard deviation ranged from 3.9 to 12.2% and 6.2 to 11.1%, respectively, and recovery varied between 90.1 and 99.7%, confirming the assay's reliability. The effectiveness and accuracy of the assay was also validated according to quality samples containing etanercept with different TNF-α concentrations, and with plasma samples from patients with AS. To complete the study, both the proposed assay and double-antibody sandwich ELISA were applied to the PK study of etanercept in patients and compared. The multiple-dose results of both analytical methods were consistent, while the drug exposure of the first dose as-detected by the proposed assay was lower than that detected by double-antibody sandwich ELISA. In conclusion, the proposed ELISA was shown to provide more accurate concentration data for therapeutic drug monitoring in comparison to commercial ELISA kits. Copyright © 2015 Elsevier B.V. All rights reserved.

Non-Enzymatic Detection of Bacterial Genomic DNA Using the Bio-Barcode Assay

PubMed Central

Hill, Haley D.; Vega, Rafael A.; Mirkin, Chad A.

2011-01-01

The detection of bacterial genomic DNA through a non-enzymatic nanomaterials based amplification method, the bio-barcode assay, is reported. The assay utilizes oligonucleotide functionalized magnetic microparticles to capture the target of interest from the sample. A critical step in the new assay involves the use of blocking oligonucleotides during heat denaturation of the double stranded DNA. These blockers bind to specific regions of the target DNA upon cooling, and prevent the duplex DNA from re-hybridizing, which allows the particle probes to bind. Following target isolation using the magnetic particles, oligonucleotide functionalized gold nanoparticles act as target recognition agents. The oligonucleotides on the nanoparticle (barcodes) act as amplification surrogates. The barcodes are then detected using the Scanometric method. The limit of detection for this assay was determined to be 2.5 femtomolar, and this is the first demonstration of a barcode type assay for the detection of double stranded, genomic DNA. PMID:17927207

Detection of Double White Dwarf Binaries with Gaia, LSST and eLISA

NASA Astrophysics Data System (ADS)

Korol, V.; Rossi, E. M.; Groot, P. J.

2017-03-01

According to simulations around 108 double degenerate white dwarf binaries are expected to be present in the Milky Way. Due to their intrinsic faintness, the detection of these systems is a challenge, and the total number of detected sources so far amounts only to a few tens. This will change in the next two decades with the advent of Gaia, the LSST and eLISA. We present an estimation of how many compact DWDs with orbital periods less than a few hours we will be able to detect 1) through electromagnetic radiation with Gaia and LSST and 2) through gravitational wave radiation with eLISA. We find that the sample of simultaneous electromagnetic and gravitational waves detections is expected to be substantial, and will provide us a powerful tool for probing the white dwarf astrophysics and the structure of the Milky Way, letting us into the era of multi-messenger astronomy for these sources.

Content modification attacks on consensus seeking multi-agent system with double-integrator dynamics.

PubMed

Dong, Yimeng; Gupta, Nirupam; Chopra, Nikhil

2016-11-01

In this paper, vulnerability of a distributed consensus seeking multi-agent system (MAS) with double-integrator dynamics against edge-bound content modification cyber attacks is studied. In particular, we define a specific edge-bound content modification cyber attack called malignant content modification attack (MCoMA), which results in unbounded growth of an appropriately defined group disagreement vector. Properties of MCoMA are utilized to design detection and mitigation algorithms so as to impart resilience in the considered MAS against MCoMA. Additionally, the proposed detection mechanism is extended to detect the general edge-bound content modification attacks (not just MCoMA). Finally, the efficacies of the proposed results are illustrated through numerical simulations.

Content modification attacks on consensus seeking multi-agent system with double-integrator dynamics

NASA Astrophysics Data System (ADS)

Dong, Yimeng; Gupta, Nirupam; Chopra, Nikhil

2016-11-01

In this paper, vulnerability of a distributed consensus seeking multi-agent system (MAS) with double-integrator dynamics against edge-bound content modification cyber attacks is studied. In particular, we define a specific edge-bound content modification cyber attack called malignant content modification attack (MCoMA), which results in unbounded growth of an appropriately defined group disagreement vector. Properties of MCoMA are utilized to design detection and mitigation algorithms so as to impart resilience in the considered MAS against MCoMA. Additionally, the proposed detection mechanism is extended to detect the general edge-bound content modification attacks (not just MCoMA). Finally, the efficacies of the proposed results are illustrated through numerical simulations.

Detection of colorectal carcinoma on double contrast barium enema when double reporting is routinely performed: an audit of current practice.

PubMed

Leslie, A; Virjee, J P

2002-03-01

To determine the sensitivity of double contrast barium enema (DCBE) in the detection of colorectal carcinoma (CRC) when double reporting is routinely performed. Over a 1-year period all patients with a diagnosis of CRC within a large teaching hospital were identified. Using computer records, any patient with CRC who had had a DCBE within 5 years of diagnosis was identified. During this time period all DCBE were double reported by the radiographer or radiology trainee who performed the enema and by a consultant radiologist specializing in gastrointestinal radiology. Over the 1-year period 169 patients were identified with a diagnosis of CRC. Seventy patients had had a DCBE within the preceding 5 years. Sixty-four patients had had CRC diagnosed on the DCBE. One patient had a sessile polyp diagnosed, which was removed at colonoscopy and found to be an invasive adenocarcinoma. In five cases (7%) the CRC was not diagnosed on DCBE. In three cases the lesions could be seen retrospectively, in one case the lesion could not be seen and in one case the examination had been incomplete. In our series the miss-rate for CRC was 7%. Previous studies have shown miss-rates of 15-24%. These studies have not routinely employed double reporting. Our results suggest that double reporting of DCBE significantly reduces the miss-rate and that this reduction is due to fewer perceptive errors. Copyright 2002 The Royal College of Radiologists.

Double layers and circuits in astrophysics

NASA Technical Reports Server (NTRS)

Alfven, H.

1986-01-01

A simple circuit is applied to the energizing of auroral particles, to solar flares, and to intergalactic double radio sources. Application to the heliospheric current systems leads to the prediction of two double layers on the Sun's axis which may give radiations detectable from Earth. Double layers in space should be classified as a new type of celestial object. It is suggested that X-ray and gamma-ray bursts may be due to exploding double layers (although annihilation is an alternative energy source). The way the most used textbooks in astrophysics treat concepts like double layers, critical velocity, pinch effects and circuits was studied. It is found that students using these textbooks remain essentially ignorant of even the existence of these, although some of the phenomena were discovered 50 yr ago.

49 CFR 830.2 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-10-01

..., search and rescue, law enforcement, aeronautical research, or biological or geological resource..., and which would normally require major repair or replacement of the affected component. Engine failure or damage limited to an engine if only one engine fails or is damaged, bent fairings or cowling...

49 CFR 830.2 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-10-01

..., search and rescue, law enforcement, aeronautical research, or biological or geological resource..., and which would normally require major repair or replacement of the affected component. Engine failure or damage limited to an engine if only one engine fails or is damaged, bent fairings or cowling...

49 CFR 830.2 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-10-01

..., search and rescue, law enforcement, aeronautical research, or biological or geological resource..., and which would normally require major repair or replacement of the affected component. Engine failure or damage limited to an engine if only one engine fails or is damaged, bent fairings or cowling...

Rheology limits for grout materials used for precast bent cap pile pockets in hot weather.

DOT National Transportation Integrated Search

2017-02-28

While prefabricated bridge elements and systems (PBES) have been used for many years in Florida, The Florida Department : of Transportation (FDOT) is currently developing local specifications for PBES to ad- dress the Federal Highway : Administration...

Smith-Purcell radiation from concave dotted gratings

NASA Astrophysics Data System (ADS)

Sergeeva, D. Yu.; Tishchenko, A. A.; Aryshev, A. S.; Strikhanov, M. N.

2018-02-01

We present the first-principles theory of Smith-Purcell effect from the concave dotted grating consisting of bent chains of separated micro- or nanoparticles. The numerical analysis demonstrates that the obtained spectral-angular distributions change significantly depending on the structure of the grating.

Relief of reinforcing congestion in beams and bent caps of concrete bridges.

DOT National Transportation Integrated Search

2012-06-01

In order to determine how to resolve the issues involving steel congestion in reinforced concrete (RC) structures, three potential solutions to this problem were researched. In the first method, reinforced concrete (RC) was mixed with steel fibers. T...

A Comparative Study of the Ionospheric TEC Measurements Using Global Ionospheric Maps of GPS, TOPEX Radar and the Bent Model

NASA Technical Reports Server (NTRS)

Ho, C.; Wilson, B.; Mannucci, A.; Lindqwister, U.; Yuan, D.

1997-01-01

Global ionospheric mapping (GIM) is a new, emerging technique for determining global ionospheric TEC (total electron content) based on measurements from a worldwide network of Global Positioning System (GPS) receivers.

49 CFR 830.2 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-10-01

..., search and rescue, law enforcement, aeronautical research, or biological or geological resource..., and which would normally require major repair or replacement of the affected component. Engine failure or damage limited to an engine if only one engine fails or is damaged, bent fairings or cowling...

Detail view of substructure, view looking south at the center ...

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

Detail view of substructure, view looking south at the center in-water frame bent - North Fork Butter Creek Bridge, Spanning North Fork Butter Creek Bridge at Milepost 76.63 on Heppner Highway (Oregon Route 74), Pilot Rock, Umatilla County, OR

Snow bending of sugar pine and ponderosa seedlings ... injury not permanent.

Treesearch

William W. Oliver

1970-01-01

Sugar pine and ponderosa pine seedlings in the Sierra Nevada, California, with stems bent by heavy snow loads were photographed the next summer and 10 years later. The photographs show that all trees recovered, leaving no permanent stem crook.

Modeling of a bubble-memory organization with self-checking translators to achieve high reliability.

NASA Technical Reports Server (NTRS)

Bouricius, W. G.; Carter, W. C.; Hsieh, E. P.; Wadia, A. B.; Jessep, D. C., Jr.

1973-01-01

Study of the design and modeling of a highly reliable bubble-memory system that has the capabilities of: (1) correcting a single 16-adjacent bit-group error resulting from failures in a single basic storage module (BSM), and (2) detecting with a probability greater than 0.99 any double errors resulting from failures in BSM's. The results of the study justify the design philosophy adopted of employing memory data encoding and a translator to correct single group errors and detect double group errors to enhance the overall system reliability.

Experimental and density functional theoretical investigations of linkage isomerism in six-coordinate FeNO(6) iron porphyrins with axial nitrosyl and nitro ligands.

PubMed

Novozhilova, Irina V; Coppens, Philip; Lee, Jonghyuk; Richter-Addo, George B; Bagley, Kimberly A

2006-02-15

A critical component of the biological activity of NO and nitrite involves their coordination to the iron center in heme proteins. Irradiation (330 < lambda < 500 nm) of the nitrosyl-nitro compound (TPP)Fe(NO)(NO(2)) (TPP = tetraphenylporphyrinato dianion) at 11 K results in changes in the IR spectrum associated with both nitro-to-nitrito and nitrosyl-to-isonitrosyl linkage isomerism. Only the nitro-to-nitrito linkage isomer is obtained at 200 K, indicating that the isonitrosyl linkage isomer is less stable than the nitrito linkage isomer. DFT calculations reveal two ground-state conformations of (porphine)Fe(NO)(NO(2)) that differ in the relative axial ligand orientations (i.e., GS parallel and GS perpendicular). In both conformations, the FeNO group is bent (156.4 degrees for GS parallel, 159.8 degrees for GS perpendicular) for this formally {FeNO}(6) compound. Three conformations of the nitrosyl-nitrito isomer (porphine)Fe(NO)(ONO) (MSa parallel, MSa perpendicular, and MSa(L)) and two conformations of the isonitrosyl-nitro isomer (porphine)Fe(ON)(NO(2)) (MSb parallel and MSb perpendicular) are identified, as are three conformations of the double-linkage isomer (porphine)Fe(ON)(ONO) (MSc parallel, MSc perpendicular, MSc(L)). Only 2 of the 10 optimized geometries contain near-linear FeNO (MSa(L)) and FeON (MSc(L)) bonds. The energies of the ground-state and isomeric structures increase in the order GS < MSa < MSb < MSc. Vibrational frequencies for all of the linkage isomers have been calculated, and the theoretical gas-phase absorption spectrum of (porphine)Fe(NO)(NO(2)) has been analyzed to obtain information on the electronic transitions responsible for the linkage isomerization. Comparison of the experimental and theoretical IR spectra does not provide evidence for the existence of a double linkage isomer of (TPP)Fe(NO)(NO(2)).

Loading Mode and Environment Effects on Surface Profile Characteristics of Martensite Plates in Cu-Based SMAs

NASA Astrophysics Data System (ADS)

Suru, Marius-Gabriel; Paraschiv, Adrian-Liviu; Lohan, Nicoleta Monica; Pricop, Bogdan; Ozkal, Burak; Bujoreanu, Leandru-Gheorghe

2014-07-01

The present work reports the influence of the loading mode provided during training under constant stress, in bending, applied to lamellar specimens of Cu-Zn-Al shape memory alloys (SMAs). During training, the specimens were bent by a load fastened at their free end, while being martensitic at room temperature and they lifted the load by one-way effect (1WE), during heating up to austenitic field. On cooling to martensite field, the lower concave surface of bent specimens was compressed, and during heating it was elongated, being subjected to a series of tension-compression cycles, during heating-cooling, respectively. Conversely, the upper convex surface of bent specimens was elongated during cooling and compressed during heating, being subjected to compression-tension cycles. Furthermore, 2WE-trained actuators were tested by means of a hydraulic installation where, this time heating-cooling cycles were performed in oil conditions. Considering that the lower concave surface of the specimens was kept in compressed state, while the upper convex surface was kept in elongated state, the study reveals the influence of the two loading modes and environments on the width of martensite plates of the specimens trained under various numbers of cycles. In this purpose, Cu-Zn-Al specimens, trained under 100-300-500 cycles, were prepared and analyzed by atomic force microscopy (AFM) as well as optical and scanning electron microscopy (OM and SEM, respectively). The analysis also included AFM micrographs corroborated with statistical evaluations in order to reveal the effects of loading mode (tension or compression) in different environmental conditions of the specimens, on the surface profile characteristics of martensite plates, revealed by electropolishing.

Corresponding-states behavior of SPC/E-based modified (bent and hybrid) water models

NASA Astrophysics Data System (ADS)

Weiss, Volker C.

2017-02-01

The remarkable and sometimes anomalous properties of water can be traced back at the molecular level to the tetrahedral coordination of molecules due to the ability of a water molecule to form four hydrogen bonds to its neighbors; this feature allows for the formation of a network that greatly influences the thermodynamic behavior. Computer simulations are becoming increasingly important for our understanding of water. Molecular models of water, such as SPC/E, are needed for this purpose, and they have proved to capture many important features of real water. Modifications of the SPC/E model have been proposed, some changing the H-O-H angle (bent models) and others increasing the importance of dispersion interactions (hybrid models), to study the structural features that set water apart from other polar fluids and from simple fluids such as argon. Here, we focus on the properties at liquid-vapor equilibrium and study the coexistence curve, the interfacial tension, and the vapor pressure in a corresponding-states approach. In particular, we calculate Guggenheim's ratio for the reduced apparent enthalpy of vaporization and Guldberg's ratio for the reduced normal boiling point. This analysis offers additional insight from a more macroscopic, thermodynamic perspective and augments that which has already been learned at the molecular level from simulations. In the hybrid models, the relative importance of dispersion interactions is increased, which turns the modified water into a Lennard-Jones-like fluid. Consequently, in a corresponding-states framework, the typical behavior of simple fluids, such as argon, is seen to be approached asymptotically. For the bent models, decreasing the bond angle turns the model essentially into a polar diatomic fluid in which the particles form linear molecular arrangements; as a consequence, characteristic features of the corresponding-states behavior of hydrogen halides emerge.

Dynamic and magneto-optic properties of bent-core liquid crystals

NASA Astrophysics Data System (ADS)

Salili, Seyyed Muhammad

In this work, we describe dynamic behavior of free-standing bent-core liquid crystal filaments under dilative and axial compressive stresses in the B7 phase. We found that such filaments demonstrate very complex structures depending on the filament's temperature relative to the isotropic phase, initial filament thickness, and velocity at which the filament is pulled or compressed. We also present our experimental methods, results and analysis of the rupture and recoil properties of several bent-core liquid crystal filaments, anticipating that they may serve as a model system for complex biological fibers. After that, we systematically describe rheological measurements for dimeric liquid crystal compounds. We studied the shear-induced alignment properties, measured the viscoelastic properties as a function of temperature, shear rate, stress and frequency, and compared the results with the rheological properties of conventional chiral nematic and smectic phases. Then we present results of chiral nematic liquid crystals composed of flexible dimer molecules subject to large DC magnetic fields between 0 and 31T. We observe that these fields lead to selective reflection of light depending on temperature and magnetic field. The band of reflected wavelengths can be tuned from ultraviolet to beyond the IR-C band. A similar effect induced by electric fields has been presented previously, and was explained by a field-induced oblique-heliconical director deformation in accordance with early theoretical predictions. Finally, we report an unprecedented magnetic field-induced shifts of the isotropic-nematic phase transition temperature observed in liquid crystal dimers where two rigid linear mesogens are linked by flexible chains of either even- or odd-numbered hydrocarbon groups. This effect is explained in terms of quenching of the thermal fluctuations and decrease of the average bend angle of molecules in the odd-numbered dimers.

Modelling resonances of the standing body exposed to vertical whole-body vibration: Effects of posture

NASA Astrophysics Data System (ADS)

Subashi, G. H. M. J.; Matsumoto, Y.; Griffin, M. J.

2008-10-01

Lumped parameter mathematical models representing anatomical parts of the human body have been developed to represent body motions associated with resonances of the vertical apparent mass and the fore-and-aft cross-axis apparent mass of the human body standing in five different postures: 'upright', 'lordotic', 'anterior lean', 'knees bent', and 'knees more bent'. The inertial and geometric parameters of the models were determined from published anthropometric data. Stiffness and damping parameters were obtained by comparing model responses with experimental data obtained previously. The principal resonance of the vertical apparent mass, and the first peak in the fore-and-aft cross-axis apparent mass, of the standing body in an upright posture (at 5-6 Hz) corresponded to vertical motion of the viscera in phase with the vertical motion of the entire body due to deformation of the tissues at the soles of the feet, with pitch motion of the pelvis out of phase with pitch motion of the upper body above the pelvis. Upward motion of the body was in phase with the forward pitch motion of the pelvis. Changing the posture of the upper body had minor effects on the mode associated with the principal resonances of the apparent mass and cross-axis apparent mass, but the mode changed significantly with bending of the legs. In legs-bent postures, the principal resonance (at about 3 Hz) was attributed to bending of the legs coupled with pitch motion of the pelvis in phase with pitch motion of the upper body. In this mode, extension of the legs was in phase with the forward pitch motion of the upper body and the upward vertical motion of the viscera.

DNA conformations in mismatch repair probed in solution by X-ray scattering from gold nanocrystals

PubMed Central

Hura, Greg L.; Tsai, Chi-Lin; Claridge, Shelley A.; Mendillo, Marc L.; Smith, Jessica M.; Williams, Gareth J.; Mastroianni, Alexander J.; Alivisatos, A. Paul; Putnam, Christopher D.; Kolodner, Richard D.; Tainer, John A.

2013-01-01

DNA metabolism and processing frequently require transient or metastable DNA conformations that are biologically important but challenging to characterize. We use gold nanocrystal labels combined with small angle X-ray scattering to develop, test, and apply a method to follow DNA conformations acting in the Escherichia coli mismatch repair (MMR) system in solution. We developed a neutral PEG linker that allowed gold-labeled DNAs to be flash-cooled and stored without degradation in sample quality. The 1,000-fold increased gold nanocrystal scattering vs. DNA enabled investigations at much lower concentrations than otherwise possible to avoid concentration-dependent tetramerization of the MMR initiation enzyme MutS. We analyzed the correlation scattering functions for the nanocrystals to provide higher resolution interparticle distributions not convoluted by the intraparticle distribution. We determined that mispair-containing DNAs were bent more by MutS than complementary sequence DNA (csDNA), did not promote tetramer formation, and allowed MutS conversion to a sliding clamp conformation that eliminated the DNA bends. Addition of second protein responder MutL did not stabilize the MutS-bent forms of DNA. Thus, DNA distortion is only involved at the earliest mispair recognition steps of MMR: MutL does not trap bent DNA conformations, suggesting migrating MutL or MutS/MutL complexes as a conserved feature of MMR. The results promote a mechanism of mismatch DNA bending followed by straightening in initial MutS and MutL responses in MMR. We demonstrate that small angle X-ray scattering with gold labels is an enabling method to examine protein-induced DNA distortions key to the DNA repair, replication, transcription, and packaging. PMID:24101514

A buoyant plume adjacent to a headland-Observations of the Elwha River plume

USGS Publications Warehouse

Warrick, J.A.; Stevens, A.W.

2011-01-01

Small rivers commonly discharge into coastal settings with topographic complexities - such as headlands and islands - but these settings are underrepresented in river plume studies compared to more simplified, straight coasts. The Elwha River provides a unique opportunity to study the effects of coastal topography on a buoyant plume, because it discharges into the Strait of Juan de Fuca on the western side of its deltaic headland. Here we show that this headland induces flow separation and transient eddies in the tidally dominated currents (O(100. cm/s)), consistent with other headlands in oscillatory flow. These flow conditions are observed to strongly influence the buoyant river plume, as predicted by the "small-scale" or "narrow" dynamical classification using Garvine's (1995) system. Because of the transient eddies and the location of the river mouth on the headland, flow immediately offshore of the river mouth is directed eastward twice as frequently as it is westward. This results in a buoyant plume that is much more frequently "bent over" toward the east than the west. During bent over plume conditions, the plume was attached to the eastern shoreline while having a distinct, cuspate front along its westernmost boundary. The location of the front was found to be related to the magnitude and direction of local flow during the preceding O(1. h), and increases in alongshore flow resulted in deeper freshwater mixing, stronger baroclinic anomalies, and stronger hugging of the coast. During bent over plume conditions, we observed significant convergence of river plume water toward the frontal boundary within 1. km of the river mouth. These results show how coastal topography can strongly influence buoyant plume behavior, and they should assist with understanding of initial coastal sediment dispersal pathways from the Elwha River during a pending dam removal project. ?? 2010.

Building Double-decker Traps for Early Detection of Emerald Ash Borer.

PubMed

McCullough, Deborah G; Poland, Therese M

2017-10-04

Emerald ash borer (EAB) (Agrilus planipennis Fairmaire), the most destructive forest insect to have invaded North America, has killed hundreds of millions of forest and landscape ash (Fraxinus spp.) trees. Several artificial trap designs to attract and capture EAB beetles have been developed to detect, delineate, and monitor infestations. Double-decker (DD) traps consist of two corrugated plastic prisms, one green and one purple, attached to a 3 m tall polyvinyl chloride (PVC) pipe supported by a t-post. The green prism at the top of the PVC pipe is baited with cis-3-hexenol, a compound produced by ash foliage. Surfaces of both prisms are coated with sticky insect glue to capture adult EAB beetles. Double-decker traps should be placed near ash trees but in open areas, exposed to sun. Double-decker trap construction and placement are presented here, along with a summary of field experiments demonstrating the efficacy of DD traps in capturing EAB beetles. In a recent study in sites with relatively low EAB densities, double-decker traps captured significantly more EAB than green or purple prism traps or green funnel traps, all of which are designed to be suspended from a branch in the canopy of ash trees. A greater percentage of double decker traps were positive, i.e., captured at least one EAB, than the prism traps or funnel traps that were hung in ash tree canopies.

Double Reading in Breast Cancer Screening: Cohort Evaluation in the CO-OPS Trial.

PubMed

Taylor-Phillips, Sian; Jenkinson, David; Stinton, Chris; Wallis, Matthew G; Dunn, Janet; Clarke, Aileen

2018-04-10

Purpose To investigate the effect of double readings by a second radiologist on recall rates, cancer detection, and characteristics of cancers detected in the National Health Service Breast Screening Program in England. Materials and Methods In this retrospective analysis, 805 206 women were evaluated through screening and diagnostic test results by extracting 1 year of routine data from 33 English breast screening centers. Centers used double reading of digital mammograms, with arbitration if there were discrepant interpretations. Information on reader decisions, with results of follow-up tests, were used to explore the effect of the second reader. The statistical tests used were the test for equality of proportions, the χ 2 test for independence, and the t test. Results The first reader recalled 4.76% of women (38 295 of 805 206 women; 95% confidence interval [CI]: 4.71%, 4.80%). Two readers recalled 6.19% of women in total (49 857 of 805 206 women; 95% CI: 6.14%, 6.24%), but arbitration of discordant readings reduced the recall rate to 4.08% (32 863 of 805 206 women; 95% CI: 4.04%, 4.12%; P < .001). A total of 7055 cancers were detected, of which 627 (8.89%; 95% CI: 8.22%, 9.55%; P < .001) were detected by the second reader only. These additional cancers were more likely to be ductal carcinoma in situ (30.5% [183 of 600] vs 22.0% [1344 of 6114]; P < .001), and additional invasive cancers were smaller (mean size, 14.2 vs 16.7 mm; P < .001), had fewer involved nodes, and were likely to be lower grade. Conclusion Double reading with arbitration reduces recall and increases cancer detection compared with single reading. Cancers detected only by the second reader were smaller, of lower grade, and had less nodal involvement. © RSNA, 2018.

MicroRNA Detection Using a Double Molecular Beacon Approach: Distinguishing Between miRNA and Pre-miRNA.

PubMed

James, Amanda Marie; Baker, Meredith B; Bao, Gang; Searles, Charles D

2017-01-01

MicroRNAs (miRNAs) are small, noncoding RNAs that post-transcriptionally regulate gene expression and are recognized for their roles both as modulators of disease progression and as biomarkers of disease activity, including neurological diseases, cancer, and cardiovascular disease (CVD). Commonly, miRNA abundance is assessed using quantitative real-time PCR (qRT-PCR), however, qRT-PCR for miRNA can be labor intensive, time consuming, and may lack specificity for detection of mature versus precursor forms of miRNA. Here, we describe a novel double molecular beacon approach to miRNA assessment that can distinguish and quantify mature versus precursor forms of miRNA in a single assay, an essential feature for use of miRNAs as biomarkers for disease. Using this approach, we found that molecular beacons with DNA or combined locked nucleic acid (LNA)-DNA backbones can detect mature and precursor miRNAs (pre-miRNAs) of low (< 1 nM) abundance in vitro . The double molecular beacon assay was accurate in assessing miRNA abundance in a sample containing a mixed population of mature and precursor miRNAs. In contrast, qRT-PCR and the single molecular beacon assay overestimated miRNA abundance. Additionally, the double molecular beacon assay was less labor intensive than traditional qRT-PCR and had 10-25% increased specificity. Our data suggest that the double molecular beacon-based approach is more precise and specific than previous methods, and has the promise of being the standard for assessing miRNA levels in biological samples.

MicroRNA Detection Using a Double Molecular Beacon Approach: Distinguishing Between miRNA and Pre-miRNA

PubMed Central

James, Amanda Marie; Baker, Meredith B.; Bao, Gang; Searles, Charles D.

2017-01-01

MicroRNAs (miRNAs) are small, noncoding RNAs that post-transcriptionally regulate gene expression and are recognized for their roles both as modulators of disease progression and as biomarkers of disease activity, including neurological diseases, cancer, and cardiovascular disease (CVD). Commonly, miRNA abundance is assessed using quantitative real-time PCR (qRT-PCR), however, qRT-PCR for miRNA can be labor intensive, time consuming, and may lack specificity for detection of mature versus precursor forms of miRNA. Here, we describe a novel double molecular beacon approach to miRNA assessment that can distinguish and quantify mature versus precursor forms of miRNA in a single assay, an essential feature for use of miRNAs as biomarkers for disease. Using this approach, we found that molecular beacons with DNA or combined locked nucleic acid (LNA)-DNA backbones can detect mature and precursor miRNAs (pre-miRNAs) of low (< 1 nM) abundance in vitro. The double molecular beacon assay was accurate in assessing miRNA abundance in a sample containing a mixed population of mature and precursor miRNAs. In contrast, qRT-PCR and the single molecular beacon assay overestimated miRNA abundance. Additionally, the double molecular beacon assay was less labor intensive than traditional qRT-PCR and had 10-25% increased specificity. Our data suggest that the double molecular beacon-based approach is more precise and specific than previous methods, and has the promise of being the standard for assessing miRNA levels in biological samples. PMID:28255356

40 CFR 270.21 - Specific part B information requirements for landfills.

Code of Federal Regulations, 2013 CFR

2013-07-01

... surface water at any future time; (ii) The double liner and leak (leachate) detection, collection, and... system, leachate collection and removal system, leak detection system, cover system, and appurtenances...