Influence of the Strength Mismatch of a Narrow Gap Welded Joint of SA508 on the Plastic η Factor

NASA Astrophysics Data System (ADS)

Koo, J. M.; Huh, Y.; Seok, C. S.

2012-11-01

In this article, the influence of the strength mismatch of a narrow gap welded joint of SA508 on the η factor was evaluated. The η factor is the principal parameter that determines the plastic portion of the J-integral. The specimens for tensile and hardness tests were collected from piping with narrow gap welding and the stress-strain curve and hardness were obtained from those. From these results, the Ramberg-Osgood (R-O) constant was obtained. Also, the finite element analysis was performed with variations in the strength mismatch and the weld width. The η factor equation considering the strength mismatch and the weld width of a narrow gap welded joint was suggested.

An overview of the technical design of MSAT mobile satellite communications services

NASA Astrophysics Data System (ADS)

Davies, N. George

The Canadian MSAT mobile satellite communications system is being implemented in cooperation with the American Mobile Satellite Consortium (AMSC). Two satellites are to be jointly acquired and each satellite is expected to backup the other. This paper describes the technical concepts of the services to be offered and the baseline planning of the infrastructure for the ground segment. MSAT service requirements are analyzed for mobile radio, telephone, data, and aeronautical services. The MSAT system will use nine beams in a narrow range of L-band frequencies with frequency reuse. Beams may be added to cover flight information areas in the Atlantic and Pacific oceans. The elements of the network architecture are: a network control centre, data hub stations, gateway stations, base stations, mobile terminals, and a signalling system to interconnect the elements of the system. The network control center will manage the network and allocate space segment capacity; data hub stations will support a switched packet mobile data service; the gateway stations will provide interconnection to the public telephone system and data networks; and the base stations will support private circuit switched voice and data services. Several alternative designs for the signalling system are described.

Photovoltaic radiation detector element

DOEpatents

Agouridis, Dimitrios C.

1983-01-01

A radiation detector element is formed of a body of semiconductor material, a coating on the body which forms a photovoltaic junction therewith, and a current collector consisting of narrow metallic strips, the aforesaid coating having an opening therein the edge of which closely approaches but is spaced from the current collector strips.

Spacecraft guidance, navigation, and control requirements for an intelligent plug-n-play avionics (PAPA) architecture

NASA Technical Reports Server (NTRS)

Kulkarni, Nilesh; Krishnakumar, Kalmaje

2005-01-01

The objective of this research is to design an intelligent plug-n-play avionics system that provides a reconfigurable platform for supporting the guidance, navigation and control (GN&C) requirements for different elements of the space exploration mission. The focus of this study is to look at the specific requirements for a spacecraft that needs to go from earth to moon and back. In this regard we will identify the different GN&C problems in various phases of flight that need to be addressed for designing such a plug-n-play avionics system. The Apollo and the Space Shuttle programs provide rich literature in terms of understanding some of the general GN&C requirements for a space vehicle. The relevant literature is reviewed which helps in narrowing down the different GN&C algorithms that need to be supported along with their individual requirements.

Magnetoresistance in Permalloy Connected Brickwork Artificial Spin Ice

NASA Astrophysics Data System (ADS)

Park, Jungsik; Le, Brian; Chern, Gia-Wei; Watts, Justin; Leighton, Chris; Schiffer, Peter

Artificial spin ice refers to a two-dimensional array of elongated ferromagnetic elements in which frustrated lattice geometry induces novel magnetic behavior. Here we examine room-temperature magnetoresistance properties of connected permalloy (Ni81Fe19) brickwork artificial spin ice. Both the longitudinal and transverse magnetoresistance of the nanostructure demonstrate an angular sensitivity that has not been previously observed. The observed magnetoresistance behavior can be explained from micromagnetic modelling using an anisotropic magnetoresistance model (AMR). As part of this study, we find that the ground state of the connected brickwork artificial spin ice can be reproducibly created by a simple field sweep in a narrow range of angles, and manifests in the magnetotransport with a distinct signal. Supported by the US Department of Energy, Office of Basic Energy Sciences, Materials Sciences and Engineering Division under Grant Number DE-SC0010778. Work at the University of Minnesota was supported by the NSF MRSEC under award DMR-1420013, and DMR-1507048.

Sparse aperiodic arrays for optical beam forming and LIDAR.

PubMed

Komljenovic, Tin; Helkey, Roger; Coldren, Larry; Bowers, John E

2017-02-06

We analyze optical phased arrays with aperiodic pitch and element-to-element spacing greater than one wavelength at channel counts exceeding hundreds of elements. We optimize the spacing between waveguides for highest side-mode suppression providing grating lobe free steering in full visible space while preserving the narrow beamwidth. Optimum waveguide placement strategies are derived and design guidelines for sparse (> 1.5 λ and > 3 λ average element spacing) optical phased arrays are given. Scaling to larger array areas by means of tiling is considered.

Basic Research Plan.

DTIC Science & Technology

1996-05-01

detection, catalysts for enhancing and controlling energetic reactions, synthesis of new compounds (e.g., narrow band-gap materials and non-linear...design for synthesis of advanced materials Fabricate porous lightweight and resilient structural materials with novel properties and uses Demonstrate...elements for 10 nm computer memory elements Demonstrate enhanced propellants and explosives with nanoparticle surface chemistry Demonstrate sensing of

Countercurrent flow limited (CCFL) heat flux in the high flux isotope reactor (HFIR) fuel element

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

Ruggles, A.E.

1990-10-12

The countercurrent flow (CCF) performance in the fuel element region of the HFIR is examined experimentally and theoretically. The fuel element consists of two concentric annuli filled with aluminum clad fuel plates of 1.27 mm thickness separated by 1.27 mm flow channels. The plates are curved as they go radially outward to accomplish constant flow channel width and constant metal-to-coolant ratio. A full-scale HFIR fuel element mock-up is studied in an adiabatic air-water CCF experiment. A review of CCF models for narrow channels is presented along with the treatment of CCFs in system of parallel channels. The experimental results aremore » related to the existing models and a mechanistic model for the annular'' CCF in a narrow channel is developed that captures the data trends well. The results of the experiment are used to calculate the CCFL heat flux of the HFIR fuel assembly. It was determined that the HFIR fuel assembly can reject 0.62 Mw of thermal power in the CCFL situation. 31 refs., 17 figs.« less

Elements configuration of the open lead test circuit

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

Fukuzaki, Yumi, E-mail: 14514@sr.kagawa-nct.ac.jp; Ono, Akira

In the field of electronics, small electronic devices are widely utilized because they are easy to carry. The devices have various functions by user’s request. Therefore, the lead’s pitch or the ball’s pitch have been narrowed and high-density printed circuit board has been used in the devices. Use of the ICs which have narrow lead pitch makes normal connection difficult. When logic circuits in the devices are fabricated with the state-of-the-art technology, some faults have occurred more frequently. It can be divided into types of open faults and short faults. We have proposed a new test method using a testmore » circuit in the past. This paper propose elements configuration of the test circuit.« less

Foot use during vertical climbing in chimpanzees (Pan troglodytes).

PubMed

Wunderlich, R E; Ischinger, S B

2017-08-01

Upright bipedalism is a hallmark of hominin locomotion, however debates continue regarding the extent of arboreal locomotion and the nature of bipedalism practiced by early hominins. Pedal form and function play a prominent role in these debates, as the foot is the element that directly interacts with the locomotor substrate. Recent finds have substantially increased the availability of associated foot remains of early hominins and emphasized the enigmatic nature of the early evolution of human bipedalism. New discoveries of associated forefoot remains have afforded the opportunity to assess relative proportions across the forefoot of fossil hominins and illuminated the need for data on relative loading across the forefoot in extant hominoids. In order to provide functional data with which to examine the relationship between bony features and load distribution across the forefoot during climbing, we present the first analysis of plantar pressure distribution across the forefoot of chimpanzees climbing a vertical support. Chimpanzees load the medial metatarsals and first toe disproportionately during vertical climbing. Peak pressures on these elements occur at the end of stance phase during climbing and are higher than on any other elements of the foot. Toe pressures are considerably higher during vertical climbing than during knuckle-walking or movement on horizontal poles, supporting the notion that the plantarly-broad and dorsally-narrow metatarsal heads in chimpanzees and some early hominins are associated with close-packing of the metatarsophalangeal joint during climbing. Copyright © 2017 Elsevier Ltd. All rights reserved.

Development of a Novel Locomotion Algorithm for Snake Robot

NASA Astrophysics Data System (ADS)

Khan, Raisuddin; Masum Billah, Md; Watanabe, Mitsuru; Shafie, A. A.

2013-12-01

A novel algorithm for snake robot locomotion is developed and analyzed in this paper. Serpentine is one of the renowned locomotion for snake robot in disaster recovery mission to overcome narrow space navigation. Several locomotion for snake navigation, such as concertina or rectilinear may be suitable for narrow spaces, but is highly inefficient if the same type of locomotion is used even in open spaces resulting friction reduction which make difficulties for snake movement. A novel locomotion algorithm has been proposed based on the modification of the multi-link snake robot, the modifications include alterations to the snake segments as well elements that mimic scales on the underside of the snake body. Snake robot can be able to navigate in the narrow space using this developed locomotion algorithm. The developed algorithm surmount the others locomotion limitation in narrow space navigation.

Ultra-thin narrow-band, complementary narrow-band, and dual-band metamaterial absorbers for applications in the THz regime

NASA Astrophysics Data System (ADS)

Astorino, Maria Denise; Frezza, Fabrizio; Tedeschi, Nicola

2017-02-01

In this paper, ultra-thin narrow-band, complementary narrow-band, and dual-band metamaterial absorbers (MMAs), exploiting the same electric ring resonator configuration, are investigated at normal and oblique incidence for both transverse electric (TE) and transverse magnetic (TM) polarizations, and with different physical properties in the THz regime. In the analysis of the ultra-thin narrow-band MMA, the limit of applicability of the transmission line model has been overcome with the introduction of a capacitance which considers the z component of the electric field. These absorbing structures have shown a wide angular response and a polarization-insensitive behavior due to the introduction of a conducting ground plane and to the four-fold rotational symmetry of the resonant elements around the propagation axis. We have adopted a retrieval procedure to extract the effective electromagnetic parameters of the proposed MMAs and we have compared the simulated and analytical results through the interference theory.

Impact of screw configuration on the particle size distribution of granules produced by twin screw granulation.

PubMed

Vercruysse, J; Burggraeve, A; Fonteyne, M; Cappuyns, P; Delaet, U; Van Assche, I; De Beer, T; Remon, J P; Vervaet, C

2015-02-01

Twin screw granulation (TSG) has been reported by different research groups as an attractive technology for continuous wet granulation. However, in contrast to fluidized bed granulation, granules produced via this technique typically have a wide and multimodal particle size distribution (PSD), resulting in suboptimal flow properties. The aim of the current study was to evaluate the impact of granulator screw configuration on the PSD of granules produced by TSG. Experiments were performed using a 25 mm co-rotating twin screw granulator, being part of the ConsiGma™-25 system (a fully continuous from-powder-to-tablet manufacturing line from GEA Pharma Systems). Besides the screw elements conventionally used for TSG (conveying and kneading elements), alternative designs of screw elements (tooth-mixing-elements (TME), screw mixing elements (SME) and cutters) were investigated using an α-lactose monohydrate formulation granulated with distilled water. Granulation with only conveying elements resulted in wide and multimodal PSD. Using kneading elements, the width of the PSD could be partially narrowed and the liquid distribution was more homogeneous. However, still a significant fraction of oversized agglomerates was obtained. Implementing additional kneading elements or cutters in the final section of the screw configuration was not beneficial. Furthermore, granulation with only TME or SME had limited impact on the width of the PSD. Promising results were obtained by combining kneading elements with SME, as for these configurations the PSD was narrower and shifted to the size fractions suitable for tableting. Copyright © 2015 Elsevier B.V. All rights reserved.

Control and gating of kinesin-microtubule motility on electrically heated thermo-chips.

PubMed

Ramsey, Laurence; Schroeder, Viktor; van Zalinge, Harm; Berndt, Michael; Korten, Till; Diez, Stefan; Nicolau, Dan V

2014-06-01

First lab-on-chip devices based on active transport by biomolecular motors have been demonstrated for basic detection and sorting applications. However, to fully employ the advantages of such hybrid nanotechnology, versatile spatial and temporal control mechanisms are required. Using a thermo-responsive polymer, we demonstrated a temperature controlled gate that either allows or disallows the passing of microtubules through a topographically defined channel. The gate is addressed by a narrow gold wire, which acts as a local heating element. It is shown that the electrical current flowing through a narrow gold channel can control the local temperature and as a result the conformation of the polymer. This is the first demonstration of a spatially addressable gate for microtubule motility which is a key element of nanodevices based on biomolecular motors.

Acoustic transducer

DOEpatents

Drumheller, Douglas S.

2000-01-01

An active acoustic transducer tool for use down-hole applications. The tool includes a single cylindrical mandrel including a shoulder defining the boundary of a narrowed portion over which is placed a sandwich-style piezoelectric tranducer assembly. The piezoelectric transducer assembly is prestressed by being placed in a thermal interference fit between the shoulder of the mandrel and the base of an anvil which is likewise positioned over the narrower portion of the mandrel. In the preferred embodiment, assembly of the tool is accomplished using a hydraulic jack to stretch the mandrel prior to emplacement of the cylindrical sandwich-style piezoelectric transducer assembly and anvil. After those elements are positioned and secured, the stretched mandrel is allowed to return substantially to its original (pre-stretch) dimensions with the result that the piezoelectric transducer elements are compressed between the anvil and the shoulder of the mandrel.

Viscoelastic Relaxation of Topographic Highs on Venus to Produce Coronae

NASA Technical Reports Server (NTRS)

Janes, Daniel M.; Squyres, Steven W.

1995-01-01

Coronae on Venus are believed to result from the gravitationally driven relaxation of topography that was originally raised by mantle diapirs. We examine this relaxation using a viscoelastic finite element code, and show that an initially plateau shaped load will evolve to the characteristic corona topography of central raised bowl, annular rim, and surrounding moat. Stresses induced by the relaxation are consistent with the development of concentric extensional fracturing common on the outer margins of corona moats. However, relaxation is not expected to produce the concentric faulting often observed on the annular rim. The relaxation timescale is shorter than the diapir cooling timescale, so loss of thermal support controls the rate at which topography is reduced. The final corona shape is supported by buoyancy and flexural stresses and will persist through geologic time. Development of lower, flatter central bowls and narrower and more pronounced annular rims and moats enhanced by thicker crusts, higher thermal gradients, and crustal thinning over the diapir.

Coupling Between CPW and Slotline Modes in Finite Ground CPW with Unequal Ground Plane Widths

NASA Technical Reports Server (NTRS)

Ponchak, George E.; Papapolymerou, John; Williams, W. D. (Technical Monitor); Tentzeris, Emmanouil M.

2002-01-01

The coupling between the desired CPW mode and the unwanted, slotline, mode is presented for finite ground coplanar waveguides with unequal ground plane widths. Measurements, quasi-static conformal mapping, and Method of Moment analysis are performed to determine the dependence of the slotline mode excitation on the physical dimensions of the FGC line and on the frequency range of operation. Introduction: Finite ground coplanar waveguide (FGC) is often used in low cost Monolithic Microwave Integrated Circuits (MMICs) because of its many advantages over microstrip and conventional CoPlanar Waveguide (CPW). It is uniplanar, which facilitates easy connection of series and shunt elements without via holes, supports a low loss, quasi-TEM mode over a wide frequency band, and since the ground planes are electrically and physically narrow, typically less than lambda/5 wide where lambda is the guided wavelength, they reduce the circuit size and the influence of higher order modes. However, they still support the parasitic slotline mode that plagues all CPW transmission lines.

Evolutionary Novelty in a Butterfly Wing Pattern through Enhancer Shuffling

PubMed Central

Pardo-Diaz, Carolina; Hanly, Joseph J.; Martin, Simon H.; Mallet, James; Dasmahapatra, Kanchon K.; Salazar, Camilo; Joron, Mathieu; Nadeau, Nicola; McMillan, W. Owen; Jiggins, Chris D.

2016-01-01

An important goal in evolutionary biology is to understand the genetic changes underlying novel morphological structures. We investigated the origins of a complex wing pattern found among Amazonian Heliconius butterflies. Genome sequence data from 142 individuals across 17 species identified narrow regions associated with two distinct red colour pattern elements, dennis and ray. We hypothesise that these modules in non-coding sequence represent distinct cis-regulatory loci that control expression of the transcription factor optix, which in turn controls red pattern variation across Heliconius. Phylogenetic analysis of the two elements demonstrated that they have distinct evolutionary histories and that novel adaptive morphological variation was created by shuffling these cis-regulatory modules through recombination between divergent lineages. In addition, recombination of modules into different combinations within species further contributes to diversity. Analysis of the timing of diversification in these two regions supports the hypothesis of introgression moving regulatory modules between species, rather than shared ancestral variation. The dennis phenotype introgressed into Heliconius melpomene at about the same time that ray originated in this group, while ray introgressed back into H. elevatus much more recently. We show that shuffling of existing enhancer elements both within and between species provides a mechanism for rapid diversification and generation of novel morphological combinations during adaptive radiation. PMID:26771987

Evolutionary Novelty in a Butterfly Wing Pattern through Enhancer Shuffling.

PubMed

Wallbank, Richard W R; Baxter, Simon W; Pardo-Diaz, Carolina; Hanly, Joseph J; Martin, Simon H; Mallet, James; Dasmahapatra, Kanchon K; Salazar, Camilo; Joron, Mathieu; Nadeau, Nicola; McMillan, W Owen; Jiggins, Chris D

2016-01-01

An important goal in evolutionary biology is to understand the genetic changes underlying novel morphological structures. We investigated the origins of a complex wing pattern found among Amazonian Heliconius butterflies. Genome sequence data from 142 individuals across 17 species identified narrow regions associated with two distinct red colour pattern elements, dennis and ray. We hypothesise that these modules in non-coding sequence represent distinct cis-regulatory loci that control expression of the transcription factor optix, which in turn controls red pattern variation across Heliconius. Phylogenetic analysis of the two elements demonstrated that they have distinct evolutionary histories and that novel adaptive morphological variation was created by shuffling these cis-regulatory modules through recombination between divergent lineages. In addition, recombination of modules into different combinations within species further contributes to diversity. Analysis of the timing of diversification in these two regions supports the hypothesis of introgression moving regulatory modules between species, rather than shared ancestral variation. The dennis phenotype introgressed into Heliconius melpomene at about the same time that ray originated in this group, while ray introgressed back into H. elevatus much more recently. We show that shuffling of existing enhancer elements both within and between species provides a mechanism for rapid diversification and generation of novel morphological combinations during adaptive radiation.

Laser window with annular grooves for thermal isolation

DOEpatents

Warner, B.E.; Horton, J.A.; Alger, T.W.

1983-07-13

A laser window or other optical element which is thermally loaded, heats up and causes optical distortions because of temperature gradients between the center and the edge. A number of annular grooves, one to three or more, are formed in the element between a central portion and edge portion, producing a web portion which concentrates the thermal gradient and thermally isolates the central portion from the edge portion, producing a uniform temperature profile across the central portion and therefore reduce the optical distortions. The grooves are narrow and closely spaced with respect to the thickness of the element, and successive grooves are formed from alternate sides of the element.

Behavior of reinforced concrete pier caps under concentrated bearing loads.

DOT National Transportation Integrated Search

1995-02-01

At congested highway interchanges, the Texas Department of Transportation (TxDOT) uses narrow concrete piers and : shallow depth steel cap girders. Research Project ()"1302 is concerned with the connection detail between these two : elements. This re...

Interaction of influenza virus polymerase with viral RNA in the 'corkscrew' conformation.

PubMed

Flick, R; Hobom, G

1999-10-01

The influenza virus RNA (vRNA) promoter structure is known to consist of the 5'- and 3'-terminal sequences of the RNA, within very narrow boundaries of 16 and 15 nucleotides, respectively. A complete set of single nucleotide substitutions led to the previously proposed model of a binary hooked or 'corkscrew' conformation for the vRNA promoter when it interacts with the viral polymerase. This functional structure is confirmed here with a complete set of complementary double substitutions, of both the regular A:U and G:C type and also the G:U type of base-pair exchanges. The proposed structure consists of a six base-pair RNA rod in the distal element in conjunction with two stem-loop structures of two short-range base-pairs (positions 2-9; 3-8). These support an exposed tetranucleotide loop within each branch of the proximal element, in an overall oblique organization due to a central unpaired A residue at position 10 in the 5' sequence. Long-range base-pairing between the entire 5' and 3' branches, as required for an unmodified 'panhandle' model, has been excluded for the proximal element, while it is known to represent the mode of interaction within the distal element. A large number of short-range base-pair exchanges in the proximal element constitute promoter-up mutations, which show activities several times above that of the wild-type in reporter gene assays. The unique overall conformation and rather few invariant nucleotides appear to be the core elements in vRNA recognition by polymerase and also in viral ribonucleoprotein packaging, to allow discrimination against the background of other RNA molecules in the cell.

Numerical simulation of evaluation of surface breaking cracks by array-lasers generated narrow-band SAW

NASA Astrophysics Data System (ADS)

Dong, Li-Ming; Ni, Chen-Yin; Shen, Zhong-Hua; Ni, Xiao-Wu

2011-09-01

Most of the factors limiting the extensive application of laser-based ultrasonic for nondestructive evaluation of surface breaking crack are its poor sensitivity, low efficiency relative to conventional contact ultrasonic methods and limit on the dimension of the cracks. For this reason, a new technique that multiplepulse narrow-band ultrasound generated by laser arrays has been proposed. It is found that crack detection dependent on spectrum of narrow-band ultrasound generated by laser arrays can be operated with low amplitude requirements. In this paper, the narrow-band ultrasound generated by pulse laser arrays interacting with surface breaking cracks has been simulated in detail by the finite element method (FEM) according to the thermoelastic theory. The pulsed array lasers were assumed to be transient heat source, and the surface acoustic wave (SAW) which propagating on the top of the plate was computed based on thermoelastic theory. Then the frequency spectrums of both reflected waves by crack and transmission ones through crack were compared with the direct waves. Results demonstrate that multiple-frequency components of the narrow-band ultrasound were varied with change of the depth of surface breaking cracks significantly, which provides the possibility for precise evaluation of surface breaking cracks.

Photoacoustic Imaging with a Commercial Ultrasound System and a Custom Probe

PubMed Central

Wang, Xueding; Fowlkes, J. Brian; Cannata, Jonathan M.; Hu, Changhong; Carson, Paul L.

2010-01-01

Building photoacoustic imaging (PAI) systems by using stand-alone ultrasound (US) units makes it convenient to take advantage of the state-of-the-art ultrasonic technologies. However, the sometimes limited receiving sensitivity and the comparatively narrow bandwidth of commercial US probes may not be sufficient to acquire high quality photoacoustic images. In this work, a high-speed PAI system has been developed using a commercial US unit and a custom built 128-element piezoelectric-polymer array (PPA) probe using a P(VDF-TrFE) film and flexible circuit to define the elements. Since the US unit supports simultaneous signal acquisition from 64 parallel receive channels, PAI data for synthetic image formation from a 64 or 128 element array aperture can be acquired after a single or dual laser firing, respectively. Therefore, 2D B-scan imaging can be achieved with a maximum frame rate up to 10 Hz, limited only by the laser repetition rate. The uniquely properties of P(VDF-TrFE) facilitated a wide -6 dB receiving bandwidth of over 120 % for the array. A specially designed 128-channel preamplifier board made the connection between the array and the system cable which not only enabled element electrical impedance matching but also further elevated the signal-to-noise ratio (SNR) to further enhance the detection of weak photoacoustic signals. Through the experiments on phantoms and rabbit ears, the good performance of this PAI system was demonstrated. PMID:21276653

The tapered slot antenna - A new integrated element for millimeter-wave applications

NASA Technical Reports Server (NTRS)

Yngvesson, K. Sigfrid; Kim, Young-Sik; Korzeniowski, T. L.; Kollberg, Erik L.; Johansson, Joakim F.

1989-01-01

Tapered slot antennas (TSAs) with a number of potential applications as single elements and focal-plane arrays are discussed. TSAs are fabricated with photolithographic techniques and integrated in either hybrid or MMIC circuits with receiver or transmitter components. They offer considerably narrower beams than other integrated antenna elements and have high aperture efficiency and packing density as array elements. Both the circuit and radiation properties of TSAs are reviewed. Topics covered include: antenna beamwidth, directivity, and gain of single-element TSAs; their beam shape and the effect of different taper shapes; and the input impedance and the effects of using thick dielectrics. These characteristics are also given for TSA arrays, as are the circuit properties of the array elements. Different array structures and their applications are also described.

High-power narrow-linewidth quasi-CW diode-pumped TEM00 1064 nm Nd:YAG ring laser.

PubMed

Liu, Yuan; Wang, Bao-shan; Xie, Shi-yong; Bo, Yong; Wang, Peng-yuan; Zuo, Jun-wei; Xu, Yi-ting; Xu, Jia-lin; Peng, Qin-jun; Cui, Da-fu; Xu, Zu-yan

2012-04-01

We demonstrated a high average power, narrow-linewidth, quasi-CW diode-pumped Nd:YAG 1064 nm laser with near-diffraction-limited beam quality. A symmetrical three-mirror ring cavity with unidirectional operation elements and an etalon was employed to realize the narrow-linewidth laser output. Two highly efficient laser modules and a 90° quartz rotator for birefringence compensation were used for the high output power. The maximum average output power of 62.5 W with the beam quality factor M(2) of 1.15 was achieved under a pump power of 216 W at a repetition rate of 500 Hz, corresponding to the optical-to-optical conversion efficiency of 28.9%. The linewidth of the laser at the maximum output power was measured to be less than 0.2 GHz.

Nuclear processes in the jets of SS 433

NASA Technical Reports Server (NTRS)

Ramaty, R.; Kozlovsky, B.; Lingenfelter, R. E.

1984-01-01

The very narrow gamma-ray lines observed at 1.495 and 6.695 MeV from SS 433 which are blueshifted 1.369 and 6.129 emissions from deexcitations of (24)Mg-asterisk and (16)O-asterisk in grains moving with the jets and inelastically excited by interactions with the ambient medium are discussed. Energetic particle interactions in grains produce very narrow gamma ray lines from deexcitation of nuclear levels whose lifetimes are long enough that the excited nuclei stop before deexcitation. The presence of grains in the jets resolves hitherto discussed difficulties of inelastic excitation models for gamma ray production in SS 433, the very narrow widths of the observed lines and the absence of other strong lines, expected from abundant elements. A model is proposed which could be distinguished from a previously proposed fusion model by gamma ray line observations.

Nuclear processes in the jets of SS433

NASA Technical Reports Server (NTRS)

Ramaty, R.; Kozlovsky, B.; Lingenfelter, R. E.

1984-01-01

The very narrow gamma-ray lines observed at 1.495 and 6.695 MeV from SS433 which are blueshifted 1.369 and 6.129 emissions from deexcitations of (24)Mg* and (16)O* in grains moving with the jets and inelastically excited by interactions with the ambient medium are discussed. Energetic particle interactions in grains produce very narrow gamma ray lines from deexcitation of nuclear levels whose lifetimes are long enough that the excited nuclei stop before deexcitation. The presence of grains in the jets resolves hitherto discussed difficulties of inelastic excitation models for gamma ray production in SS433, the very narrow widths of the observed lines and the absence of other strong lines, expected from abundant elements. A model is proposed which could be distinguished from a previously proposed fusion model by gamma ray line observations.

Low bandgap mid-infrared thermophotovoltaic arrays based on InAs

NASA Astrophysics Data System (ADS)

Krier, A.; Yin, M.; Marshall, A. R. J.; Kesaria, M.; Krier, S. E.; McDougall, S.; Meredith, W.; Johnson, A. D.; Inskip, J.; Scholes, A.

2015-11-01

We demonstrate the first low bandgap thermophotovoltaic (TPV) arrays capable of operating with heat sources at temperatures as low as 345 °C, which is the lowest ever reported. The individual array elements are based on narrow band gap InAs/InAs0.61Sb0.13P0.26 photodiode structures. External power conversion efficiency was measured to be ∼3% from a single element at room temperature, using a black body at 950 °C. Both 25-element and 65-element arrays were fabricated and exhibited a TPV response at different source temperatures in the range 345-950 °C suitable for electricity generation from waste heat and other applications.

EFFECTS OF LASER RADIATION ON MATTER. LASER PLASMA: Pattern of the expansion of laser plasmas of various elements in a magnetic field

NASA Astrophysics Data System (ADS)

Bryunetkin, B. A.; Begimkulov, U. Sh; Dyakin, V. M.; Koldashov, G. A.; Repin, A. Yu; Stupitskiĭ, E. L.; Faenov, A. Ya

1993-02-01

The expansion of laser plasmas of the elements Be, Al, Cu, and Pb in a static transverse magnetic field B<=2.7 T has been studied experimentally. The plasma was produced by a ruby laser at a power density no greater than 1012 W/cm2. For all the elements, a characteristic "two-petal" expansion pattern is observed. At a certain distance from the target, the two petals coalesce into a narrow jet. The radius of curvature of the petals and the position of the coalescence point depend on the field strength and the atomic weight of the element.

Control of Gas Tungsten Arc welding pool shape by trace element addition to the weld pool

DOEpatents

Heiple, C.R.; Burgardt, P.

1984-03-13

An improved process for Gas Tungsten Arc welding maximizes the depth/width ratio of the weld pool by adding a sufficient amount of a surface active element to insure inward fluid flow, resulting in deep, narrow welds. The process is especially useful to eliminate variable weld penetration and shape in GTA welding of steels and stainless steels, particularly by using a sulfur-doped weld wire in a cold wire feed technique.

Quantitative evaluation of potential irradiation geometries for carbon-ion beam grid therapy.

PubMed

Tsubouchi, Toshiro; Henry, Thomas; Ureba, Ana; Valdman, Alexander; Bassler, Niels; Siegbahn, Albert

2018-03-01

Radiotherapy using grids containing cm-wide beam elements has been carried out sporadically for more than a century. During the past two decades, preclinical research on radiotherapy with grids containing small beam elements, 25 μm-0.7 mm wide, has been performed. Grid therapy with larger beam elements is technically easier to implement, but the normal tissue tolerance to the treatment is decreasing. In this work, a new approach in grid therapy, based on irradiations with grids containing narrow carbon-ion beam elements was evaluated dosimetrically. The aim formulated for the suggested treatment was to obtain a uniform target dose combined with well-defined grids in the irradiated normal tissue. The gain, obtained by crossfiring the carbon-ion beam grids over a simulated target volume, was quantitatively evaluated. The dose distributions produced by narrow rectangular carbon-ion beams in a water phantom were simulated with the PHITS Monte Carlo code. The beam-element height was set to 2.0 cm in the simulations, while the widths varied from 0.5 to 10.0 mm. A spread-out Bragg peak (SOBP) was then created for each beam element in the grid, to cover the target volume with dose in the depth direction. The dose distributions produced by the beam-grid irradiations were thereafter constructed by adding the dose profiles simulated for single beam elements. The variation of the valley-to-peak dose ratio (VPDR) with depth in water was thereafter evaluated. The separation of the beam elements inside the grids were determined for different irradiation geometries with a selection criterion. The simulated carbon-ion beams remained narrow down to the depths of the Bragg peaks. With the formulated selection criterion, a beam-element separation which was close to the beam-element width was found optimal for grids containing 3.0-mm-wide beam elements, while a separation which was considerably larger than the beam-element width was found advantageous for grids containing 0.5-mm-wide beam elements. With the single-grid irradiation setup, the VPDRs were close to 1.0 already at a distance of several cm from the target. The valley doses given to the normal tissue at 0.5 cm distance from the target volume could be limited to less than 10% of the mean target dose if a crossfiring setup with four interlaced grids was used. The dose distributions produced by grids containing 0.5- and 3.0-mm wide beam elements had characteristics which could be useful for grid therapy. Grids containing mm-wide carbon-ion beam elements could be advantageous due to the technical ease with which these beams can be produced and delivered, despite the reduced threshold doses observed for early and late responding normal tissue for beams of millimeter width, compared to submillimetric beams. The treatment simulations showed that nearly homogeneous dose distributions could be created inside the target volumes, combined with low valley doses in the normal tissue located close to the target volume, if the carbon-ion beam grids were crossfired in an interlaced manner with optimally selected beam-element separations. The formulated selection criterion was found useful for the quantitative evaluation of the dose distributions produced by the different irradiation setups. © 2018 The Authors. Medical Physics published by Wiley Periodicals, Inc. on behalf of American Association of Physicists in Medicine.

Thermal Design and Analysis of the Optical Telescope Assembly for the Gondola for High Altitude Planetary Science

NASA Technical Reports Server (NTRS)

O'Connor, Brian; Brooks, Thomas

2017-01-01

The NASA Gondola for High Altitude Planetary Science (GHAPS) project is an effort to design, build, and fly a balloon-borne platform for planetary science missions. GHAPS observations will be in the 300 nm to 5 micron wavelength region covering UV, visible, and near-mid IR. The primary element of the project is the Optical Telescope Assembly (OTA). It is a one meter aperture narrow-field-of-view telescope that contains the primary and secondary mirrors, the support system/metering structure, a secondary mirror focusing system, baffles, and insulation. This paper presents the thermal design and analysis that has been done to support the design of the OTA. A major part of the thermal analysis was bounding the flight environment for the six potential Columbia Scientific Balloon Facility launch sites. These analyses were used to give input into the Structural Thermal Optical Performance (STOP) analysis of the telescope. Also the analysis was used to select heater sizes for the few OTA associated electronic components. Currently the telescope is scheduled to have its first flight in 2019.

A spatial decision support system (SDSS) for sustainable tourism planning in Cameron Highlands, Malaysia

NASA Astrophysics Data System (ADS)

Aminu, M.; Matori, A. N.; Yusof, K. W.

2014-02-01

The study describes a methodological approach based on an integrated use of Geographic Information System (GIS) and Analytic Network Process (ANP) of Multi Criteria Evaluation (MCE) to determine nature conservation and tourism development priorities among the highland areas. A set of criteria and indicators were defined to evaluate the highlands biodiversity conservation and tourism development. Pair wise comparison technique was used in order to support solution of a decision problem by evaluating possible alternatives from different perspectives. After the weights have been derived from the pairwise comparison technique, the next step was to compute the unweighted supermatrix, weighted supermatrix and the limit matrix. The limit matrix was normalized to obtain the priorities and the results transferred into GIS environment. Elements evaluated and ranked were represented by criterion maps. Map layers reflecting the opinion of different experts involved were summed using the weighted overlay approach of GIS. Subsequently sustainable tourism development scenarios were generated. The generation of scenarios highlighted the critical issues of the decision problem because it allows one to gradually narrow down a problem.

Efficient finite element simulation of slot spirals, slot radomes and microwave structures

NASA Technical Reports Server (NTRS)

Gong, J.; Volakis, J. L.

1995-01-01

This progress report contains the following two documents: (1) 'Efficient Finite Element Simulation of Slot Antennas using Prismatic Elements' - A hybrid finite element-boundary integral (FE-BI) simulation technique is discussed to treat narrow slot antennas etched on a planar platform. Specifically, the prismatic elements are used to reduce the redundant sampling rates and ease the mesh generation process. Numerical results for an antenna slot and frequency selective surfaces are presented to demonstrate the validity and capability of the technique; and (2) 'Application and Design Guidelines of the PML Absorber for Finite Element Simulations of Microwave Packages' - The recently introduced perfectly matched layer (PML) uniaxial absorber for frequency domain finite element simulations has several advantages. In this paper we present the application of PML for microwave circuit simulations along with design guidelines to obtain a desired level of absorption. Different feeding techniques are also investigated for improved accuracy.

Calibration of AXAF Mirrors Using Synchrotron Radiation

NASA Astrophysics Data System (ADS)

Graessle, D. E.; Fitch, J.; Harris, B.; Hsieh, P.; Nguyen, D.; Hughes, J.; Schwartz, D.; Blake, R.

1995-12-01

Over the past five years, the SAO AXAF Mission Support Team has been developing methods and systems to provide a tunable, narrow-energy-bandwidth calibration of the reflecting efficiency of the AXAF High Resolution Mirror Assembly. A group of synchrotron beamlines at the National Synchrotron Light Source was selected for this calibration. Measurements and analysis are now available for the 2-12 keV energy range. An X-ray beam with energy purity E/Delta E ~ 5000 has been used to calibrate several witness flats which were coated simultaneously with elements of the flight mirror. In the iridium-edge range, (2010-3200 eV), these may be the first measurements ever to be reported. Optical constants for the iridium have been derived from a fit of reflectance versus grazing angle to a Fresnel equation model for the 2-12 keV energy range. The eight AXAF HRMA elements are being coated individually; however reflectance results are quite consistent from coating run to coating run for the first few pieces. The measurement precision is approximately 0.2%-0.4%. Residuals of the fit are nearly always within 1.0% of the data values, in the angle ranges of interest to AXAF.

NEW ADVANCES IN BORON SOIL CHEMISTRY

EPA Science Inventory

Boron is an essential plant micronutrient for which the range between deficiency and toxicity is narrower than for any other nutrient element. Plants respond directly to the amount of B in soil solution and only indirectly to the amount of B adsorbed on soil particle surfaces. ...

NEW ADVANCES IN BORON SOIL CHEMISTRY - Paper

EPA Science Inventory

Boron is an essential plant micronutrient for which the range between deficiency and toxicity is narrower than for any other nutrient element. Plants respond directly to the amount of B in soil solution and only indirectly to the amount of B adsorbed on soil particle surfaces. ...

Neutral details associated with emotional events are encoded: evidence from a cued recall paradigm.

PubMed

Mickley Steinmetz, Katherine R; Knight, Aubrey G; Kensinger, Elizabeth A

2016-11-01

Enhanced emotional memory often comes at the cost of memory for surrounding background information. Narrowed-encoding theories suggest that this is due to narrowed attention for emotional information at encoding, leading to impaired encoding of background information. Recent work has suggested that an encoding-based theory may be insufficient. Here, we examined whether cued recall-instead of previously used recognition memory tasks-would reveal evidence that non-emotional information associated with emotional information was effectively encoded. Participants encoded positive, negative, or neutral objects on neutral backgrounds. At retrieval, they were given either the item or the background as a memory cue and were asked to recall the associated scene element. Counter to narrowed-encoding theories, emotional items were more likely than neutral items to trigger recall of the associated background. This finding suggests that there is a memory trace of this contextual information and that emotional cues may facilitate retrieval of this information.

Community violence, children's development, and mass media: in pursuit of new insights, new goals, and new strategies.

PubMed

Friedlander, B Z

1993-02-01

Community violence that victimizes children is an unmitigated evil that is exacerbated by vast economic and social forces that leave people in central cities and the rural countryside adrift on seas of rolelessness, hopelessness, group disintegration, and alienation. The contemporary drug scene and the easy availability of guns greatly intensify violence on a local scale, while crimes of violence, especially with guns, appear to be level or declining in the nation as a whole. Claims that the persistently high levels of violence in mass media, mostly television, are largely responsible for violence in society represent narrow views of very large issues. These narrow views overlook essential elements of both phenomena--violence and media. Direct models of interpersonal violence in families and in the community probably give rise to more violent behavior than indirect models in media. Disinhibitory and provocative aspects of media probably do as much or more to trigger violent behavior than violent narratives and violent actions. Comprehensive meta-analysis indicates that prosocial messages on television can have greater effects on behavior than antisocial messages. These data support the contention that mass media can play a strong and positive role in alleviating some of the distress of victims of community violence, and in redirecting the behavior of some of its perpetrators so as to protect the children.

Fracture strength and probability of survival of narrow and extra-narrow dental implants after fatigue testing: In vitro and in silico analysis.

PubMed

Bordin, Dimorvan; Bergamo, Edmara T P; Fardin, Vinicius P; Coelho, Paulo G; Bonfante, Estevam A

2017-07-01

To assess the probability of survival (reliability) and failure modes of narrow implants with different diameters. For fatigue testing, 42 implants with the same macrogeometry and internal conical connection were divided, according to diameter, as follows: narrow (Ø3.3×10mm) and extra-narrow (Ø2.9×10mm) (21 per group). Identical abutments were torqued to the implants and standardized maxillary incisor crowns were cemented and subjected to step-stress accelerated life testing (SSALT) in water. The use-level probability Weibull curves, and reliability for a mission of 50,000 and 100,000 cycles at 50N, 100, 150 and 180N were calculated. For the finite element analysis (FEA), two virtual models, simulating the samples tested in fatigue, were constructed. Loading at 50N and 100N were applied 30° off-axis at the crown. The von-Mises stress was calculated for implant and abutment. The beta (β) values were: 0.67 for narrow and 1.32 for extra-narrow implants, indicating that failure rates did not increase with fatigue in the former, but more likely were associated with damage accumulation and wear-out failures in the latter. Both groups showed high reliability (up to 97.5%) at 50 and 100N. A decreased reliability was observed for both groups at 150 and 180N (ranging from 0 to 82.3%), but no significant difference was observed between groups. Failure predominantly involved abutment fracture for both groups. FEA at 50N-load, Ø3.3mm showed higher von-Mises stress for abutment (7.75%) and implant (2%) when compared to the Ø2.9mm. There was no significant difference between narrow and extra-narrow implants regarding probability of survival. The failure mode was similar for both groups, restricted to abutment fracture. Copyright © 2017 Elsevier Ltd. All rights reserved.

A systematic review of chronic disease management interventions in primary care.

PubMed

Reynolds, Rebecca; Dennis, Sarah; Hasan, Iqbal; Slewa, Jan; Chen, Winnie; Tian, David; Bobba, Sangeetha; Zwar, Nicholas

2018-01-09

Primary and community care are key settings for the effective management of long term conditions. We aimed to evaluate the pattern of health outcomes in chronic disease management interventions for adults with physical health problems implemented in primary or community care settings. The methods were based on our previous review published in 2006. We performed database searches for articles published from 2006 to 2014 and conducted a systematic review with narrative synthesis using the Cochrane Effective Practice and Organisation of Care taxonomy to classify interventions and outcomes. The interventions were mapped to Chronic Care Model elements. The pattern of outcomes related to interventions was summarized by frequency of statistically significant improvements in health care provision and patient outcomes. A total of 9589 journal articles were retrieved from database searches and snowballing. After screening and verification, 165 articles that detailed 157 studies were included. There were few studies with Health Care Organization (1.9% of studies) or Community Resources (0.6% of studies) as the primary intervention element. Self-Management Support interventions (45.8% of studies) most frequently resulted in improvements in patient-level outcomes. Delivery System Design interventions (22.6% of studies) showed benefits in both professional and patient-level outcomes for a narrow range of conditions. Decision Support interventions (21.3% of studies) had impact limited to professional-level outcomes, in particular use of medications. The small number of studies of Clinical Information System interventions (8.9%) showed benefits for both professional- and patient-level outcomes. The published literature has expanded substantially since 2006. This review confirms that Self-Management Support is the most frequent Chronic Care Model intervention that is associated with statistically significant improvements, predominately for diabetes and hypertension.

Field testing of the Wolf Creek curved girder bridge : part I : vibration tests.

DOT National Transportation Integrated Search

2009-01-01

The Wolf Creek Bridge is a curved, multi-girder three span steel composite bridge located south of Narrows, Virginia, that was completed in 2006. A finite element model of the bridge revealed that pier flexibility may be important in modeling the bri...

Field testing of the Wolf Creek curved girder bridge : part II : strain measurements.

DOT National Transportation Integrated Search

2009-01-01

The Wolf Creek Bridge is a curved, multi-girder three span steel composite bridge located south of Narrows, Virginia, that was completed in 2006. A finite element (FE) model of the bridge revealed that pier flexibility may be important in modeling th...

The narrow pass band filter of tunable 1D phononic crystals with a dielectric elastomer layer

NASA Astrophysics Data System (ADS)

Wu, Liang-Yu; Wu, Mei-Ling; Chen, Lien-Wen

2009-01-01

In this paper, we study the defect bands of a 1D phononic crystal consisting of aluminum (Al) and polymethyl methacrylate (PMMA) layers with a dielectric elastomer (DE) defect layer. The plane wave expansion (PWE) method and supercell calculation are used to calculate the band structure and the defect bands. The transmission spectra are obtained using the finite element method (FEM). Since the thickness of the dielectric elastomer defect layer is controlled by applying an electric voltage, the frequencies of the defect bands can be tuned. A narrow pass band filter can be developed and designed by using the dielectric elastomer.

The blues broaden, but the nasty narrows: attentional consequences of negative affects low and high in motivational intensity.

PubMed

Gable, Philip; Harmon-Jones, Eddie

2010-02-01

Positive and negative affects high in motivational intensity cause a narrowing of attentional focus. In contrast, positive affects low in motivational intensity cause a broadening of attentional focus. The attentional consequences of negative affects low in motivational intensity have not been experimentally investigated. Experiment 1 compared the attentional consequences of negative affect low in motivational intensity (sadness) relative to a neutral affective state. Results indicated that low-motivation negative affect caused attentional broadening. Experiment 2 found that disgust, a high-motivation negative affect not previously investigated in attentional studies, narrowed attentional focus. These experiments support the conceptual model linking high-motivation affective states to narrowed attention and low-motivation affective states to broadened attention.

Performance analysis and material dependence of micro holographic optical elements as couplers for fiber optic communication

NASA Astrophysics Data System (ADS)

Ambadiyil, Sajan; Prasannan, G.; Sathyan, Jithesh; Ajith Kumar, P. T.

2005-01-01

Holographic Optical Elements (HOEs) are gaining much importance and finding newer and better applications in areas of optical fiber communication and optical information processing systems. In contrast to conventional HOEs, optical communication and information systems require smaller and efficient elements of desired characteristics and transfer functions. Such Micro Holographic Optical Elements (MHOEs) can either be an HOE, recorded with two narrow beams of laser light or a segment cut from a larger HOE (SHOEs), and recorded in the conventional manner. In this study, micro holographic couplers, having specific focusing and diffraction characteristics were recorded in different holographic recording media such as silver halide and dichromated gelatin. Wavelength response of the elements was tested at 633 nm and 442 nm. Variation in diffraction efficiency/coupling factor, and insertion loss of the elements were studied. The paper reports in detail about the above results and related design considerations.

A review of concentrated flow erosion processes on rangelands: fundamental understanding and knowledge gaps

USDA-ARS?s Scientific Manuscript database

Concentrated flow erosion processes are distinguished from splash and sheetflow processes in their enhanced ability to mobilize and transport large amounts of soil, water and dissolved elements. On rangelands, soil, nutrients and water are scarce and only narrow margins of resource losses are tolera...

Narrowing the Achievement Gap: Factors That Support English Learner and Hispanic Student Academic Achievement in an Urban Intermediate School

ERIC Educational Resources Information Center

Flores, Patricia Arleen

2010-01-01

A persistent and pervasive disparity in academic achievement exists between ethnic minority and English Learner students and their White and Asian peers. This qualitative single-case study of a high-poverty, high-performing middle school focused on the cultural norms, practices, and programs that were perceived to be contributing to narrowing the…

Why Hart found narrow ecospheres--a minor science mystery solved.

PubMed

Levenson, Barton Paul

2015-05-01

To explain why two NASA computer simulation studies in the 1970s (Hart, 1978 , 1979 ) briefly rocked the subfield of astrobiology and SETI studies by showing very narrow habitable zones (HZs) for solar-type stars. Although other studies later supported wider HZs, it was never clear why the Hart simulations found the narrow limits they did. Investigation of the state of climate studies and radiative transfer models in the period 1960-1970 provides a likely explanation. Hart's findings were in line with earlier results, preventing him from noticing that his radiation model was inadequate.

Spark discharge trace element detection system

DOEpatents

Adler-Golden, Steven; Bernstein, Lawrence S.; Bien, Fritz

1988-01-01

A spark discharge trace element detection system is provided which includes a spark chamber including a pair of electrodes for receiving a sample of gas to be analyzed at no greater than atmospheric pressure. A voltage is provided across the electrodes for generating a spark in the sample. The intensity of the emitted radiation in at least one primary selected narrow band of the radiation is detected. Each primary band corresponds to an element to be detected in the gas. The intensity of the emission in each detected primary band is integrated during the afterglow time interval of the spark emission and a signal representative of the integrated intensity of the emission in each selected primary bond is utilized to determine the concentration of the corresponding element in the gas.

Spark discharge trace element detection system

DOEpatents

Adler-Golden, S.; Bernstein, L.S.; Bien, F.

1988-08-23

A spark discharge trace element detection system is provided which includes a spark chamber including a pair of electrodes for receiving a sample of gas to be analyzed at no greater than atmospheric pressure. A voltage is provided across the electrodes for generating a spark in the sample. The intensity of the emitted radiation in at least one primary selected narrow band of the radiation is detected. Each primary band corresponds to an element to be detected in the gas. The intensity of the emission in each detected primary band is integrated during the afterglow time interval of the spark emission and a signal representative of the integrated intensity of the emission in each selected primary bond is utilized to determine the concentration of the corresponding element in the gas. 12 figs.

Spectral diffraction efficiency characterization of broadband diffractive optical elements.

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

Choi, Junoh; Cruz-Cabrera, Alvaro Augusto; Tanbakuchi, Anthony

Diffractive optical elements, with their thin profile and unique dispersion properties, have been studied and utilized in a number of optical systems, often yielding smaller and lighter systems. Despite the interest in and study of diffractive elements, the application has been limited to narrow spectral bands. This is due to the etch depths, which are optimized for optical path differences of only a single wavelength, consequently leading to rapid decline in efficiency as the working wavelength shifts away from the design wavelength. Various broadband diffractive design methodologies have recently been developed that improve spectral diffraction efficiency and expand the workingmore » bandwidth of diffractive elements. We have developed diffraction efficiency models and utilized the models to design, fabricate, and test two such extended bandwidth diffractive designs.« less

Cryogenic Detectors (Narrow Field Instruments)

NASA Astrophysics Data System (ADS)

Hoevers, H.; Verhoeve, P.

Two cryogenic imaging spectrometer arrays are currently considered as focal plane instruments for XEUS. The narrow field imager 1 (NFI 1) will cover the energy range from 0.05 to 3 keV with an energy resolution of 2 eV, or better, at 500 eV. A second narrow field imager (NFI 2) covers the energy range from 1 to 15 keV with an energy resolution of 2 eV (at 1 keV) and 5 eV (at 7 keV), creating some overlap with part of the NFI 1 energy window. Both narrow field imagers have a 0.5 arcmin field of view. Their imaging capabilities are matched to the XEUS optics of 2 to 5 arcsec leading to 1 arcsec pixels. The detector arrays will be cooled by a closed cycle system comprising a mechanical cooler with a base temperature of 2.5 K and either a low temperature 3He sorption pump providing the very low temperature stage and/or an Adiabatic Demagnetization Refrigerator (ADR). The ADR cooler is explicitly needed to cool the NFI 2 array. The narrow field imager 1} Currently a 48 times 48 element array of superconducting tunnel junctions (STJ) is envisaged. Its operating temperature is in the range between 30 and 350 mK. Small, single Ta STJs (20-50 mum on a side) have shown 3.5 eV (FWHM) resolution at E = 525 eV and small arrays have been successfully demonstrated (6 times 6 pixels), or are currently tested (10 times 12 pixels). Alternatively, a prototype Distributed Read-Out Imaging Device (DROID), consisting of a linear superconducting Ta absorber of 20 times 100 mum2, including a 20 times 20 mum STJ for readout at either end, has shown a measured energy resolution of 2.4 eV (FWHM) at E = 500 eV. Simulations involving the diffusion properties as well as loss and tunnel rates have shown that the performance can be further improved by slight modifications in the geometry, and that the size of the DROIDS can be increased to 0.5-1.0 mm without loss in energy resolution. The relatively large areas and good energy resolution compared to single STJs make DROIDS good candidates for the basic elements of the NFI 1 detector array. With a DROID-based array of 48 times 10 elements covering the NFI 1 field of view of 0.5 arcmin, the number of signal wires would already be reduced by a factor 2.4 compared to a 48 times 48 array of single pixels. While the present prototype DROIDS are still covered with a 480 nm thick SiOx insulation layer, this layer could easily be reduced in thickness or omitted. The detection efficiency of such a device with a 500 nm thick Ta absorber would be >80% in the energy range of 100-3000eV, without any disturbing contributions from other layers as in single STJs. Further developments involve devices of lower Tc-superconductors for better energy resolution and faster diffusion (e.g. Mo). The narrow field imager 2 The NFI 2 will consist of an array of 32 times 32 detector pixels. Each detector is a microcalorimeter which consists of a a superconducting to normal phase transition edge thermometer (transition edge sensor, TES) with an operating temperature of 100 mK, and an absorber which allows a detection efficiency of >90% and a filling factor of the focal plane in excess of 90%. Single pixel microcalorimeters with a Ti/Au TES have already shown an energy resolution of 3.9 eV at 5.89 keV in combination with a thermal response time of 100 mus. These results imply that they the high-energy requirement for XEUS can be met, in terms of energy resolution and response time. It has been demonstrated that bismuth can be applied as absorber material without impeding on the detector performance. Bi increases the stopping power in excess of 90 % and allows for a high filling factor since the absorber is can be modeled in the shape of a mushroom, allowing that the wiring to the detector and the thermal support structure are placed under the hat of the mushroom. In order to realize the NFI 2 detector array, there are two major development areas. Firstly, there is the development of micromachined Si and SiN structures that will provide proper cooling for each of the pixels and the production of small membranes to support the detector pixels. Micromechanical prototypes of this cooling and support structure have been made and are currently characterized. Secondly, the read-out of the array has to be developed. The current baseline for research is frequency division multiplexing (FDM) which will allow that a large detector can be read-out with a minimum of low-temperature electronics (Superconducting Quantum Interference Devices) and with a minimum of wires to the detector, thus reducing the thermal load on the detector cooling. Significant progress has been achieved since a microcalorimeter has been successfully biased at a frequency of 46 kHz, showing a performance which is very similar to that under conventional dc-bias conditions, proving the FDM concept.

Multi-level damage identification with response reconstruction

NASA Astrophysics Data System (ADS)

Zhang, Chao-Dong; Xu, You-Lin

2017-10-01

Damage identification through finite element (FE) model updating usually forms an inverse problem. Solving the inverse identification problem for complex civil structures is very challenging since the dimension of potential damage parameters in a complex civil structure is often very large. Aside from enormous computation efforts needed in iterative updating, the ill-condition and non-global identifiability features of the inverse problem probably hinder the realization of model updating based damage identification for large civil structures. Following a divide-and-conquer strategy, a multi-level damage identification method is proposed in this paper. The entire structure is decomposed into several manageable substructures and each substructure is further condensed as a macro element using the component mode synthesis (CMS) technique. The damage identification is performed at two levels: the first is at macro element level to locate the potentially damaged region and the second is over the suspicious substructures to further locate as well as quantify the damage severity. In each level's identification, the damage searching space over which model updating is performed is notably narrowed down, not only reducing the computation amount but also increasing the damage identifiability. Besides, the Kalman filter-based response reconstruction is performed at the second level to reconstruct the response of the suspicious substructure for exact damage quantification. Numerical studies and laboratory tests are both conducted on a simply supported overhanging steel beam for conceptual verification. The results demonstrate that the proposed multi-level damage identification via response reconstruction does improve the identification accuracy of damage localization and quantization considerably.

Eolian additions to late Quaternary alpine soils, Indian Peaks Wilderness Area, Colorado Front Range

USGS Publications Warehouse

Muhs, D.R.; Benedict, J.B.

2006-01-01

Surface horizons of many alpine soils on Quaternary deposits in high-mountain settings are enriched in silt. The origin of these particles has been debated, particularly in the Rocky Mountain region of North America. The most common explanations are frost shattering of coarser particles and eolian additions from distant sources. We studied soil A horizons on alpine moraines of late-glacial (Satanta Peak) age in the Colorado Front Range. Surface horizons of soils on these moraines are enriched in silt and have a particle size distribution that resembles loess and dust deposits found elsewhere. The compositions of sand and silt fractions of the soils were compared to possible local source rocks, using immobile trace elements Ti, Nb, Zr, Ce, and Y. The sand fractions of soils have a wide range of trace element ratios, similar to the range of values in the local biotite gneiss bedrock. In contrast, silt fractions have narrower ranges of trace element ratios that do not overlap the range of these ratios in biotite gneiss. The particle size and geochemical results support an interpretation that silts in these soils are derived from airborne dust. Eolian silts were most likely derived from distant sources, such as the semiarid North Park and Middle Park basins to the west. We hypothesize that much of the eolian influx to soils of the Front Range occurred during an early to mid-Holocene warm period, when sediment availability in semiarid source basins was at a maximum.

Primary and Secondary Superresolution by Data Inversion (Postprint)

DTIC Science & Technology

2005-06-06

4. H. Liu, Y. Yan, Q. Tan, and G. Jin, “Theories for the design of diffractive superresolution elements and limits of optical superresolution ,” J...optical system. This latter approach is often referred to as “ optical superresolution ” and is useful when a narrow pre-detection PSF is desired as is the

Conically scanned lidar telescope using holographic optical elements

NASA Technical Reports Server (NTRS)

Schwemmer, Geary K.; Wilkerson, Thomas D.

1992-01-01

Holographic optical elements (HOE) using volume phase holograms make possible a new class of lightweight scanning telescopes having advantages for lidar remote sensing instruments. So far, the only application of HOE's to lidar has been a non-scanning receiver for a laser range finder. We introduce a large aperture, narrow field of view (FOV) telescope used in a conical scanning configuration, having a much smaller rotating mass than in conventional designs. Typically, lidars employ a large aperture collector and require a narrow FOV to limit the amount of skylight background. Focal plane techniques are not good approaches to scanning because they require a large FOV within which to scan a smaller FOV mirror or detector array. Thus, scanning lidar systems have either used a large flat scanning mirror at which the receiver telescope is pointed, or the entire telescope is steered. We present a concept for a conically scanned lidar telescope in which the only moving part is the HOE which serves as the primary collecting optic. We also describe methods by which a multiplexed HOE can be used simultaneously as a dichroic beamsplitter.

First-principle approach based bandgap engineering for cubic boron nitride doped with group IIA elements

NASA Astrophysics Data System (ADS)

Li, Yubo; Wang, Pengtao; Hua, Fei; Zhan, Shijie; Wang, Xiaozhi; Luo, Jikui; Yang, Hangsheng

2018-03-01

Electronic properties of cubic boron nitride (c-BN) doped with group IIA elements were systematically investigated using the first principle calculation based on density functional theory. The electronic bandgap of c-BN was found to be narrowed when the impurity atom substituted either the B (IIA→B) or the N (IIA→N) atom. For IIA→B, a shallow accept level degenerated into valence band (VB); while for IIA→N, a shallow donor level degenerated conduction band (CB). In the cases of IIBe→N and IIMg→N, deep donor levels were also induced. Moreover, a zigzag bandgap narrowing pattern was found, which is in consistent with the variation pattern of dopants' radius of electron occupied outer s-orbital. From the view of formation energy, the substitution of B atom under N-rich conditions and the substitution of N atom under B-rich conditions were energetically favored. Our simulation results suggested that Mg and Ca are good candidates for p-type dopants, and Ca is the best candidate for n-type dopant.

Dye laser traveling wave amplifier

NASA Technical Reports Server (NTRS)

Davidson, F.; Hohman, J.

1985-01-01

Injection locking was applied to a cavity-dumped coaxial flashlamp pumped dye laser in an effort to obtain nanosecond duration pulses which have both high energy and narrow-linewidth. In the absence of an injected laser pulse, the cavity-dumped dye laser was capable of generating high energy (approx. 60mJ) nanosecond duration output pulses. These pulses, however, had a fixed center wavelength and were extremely broadband (approx. 6nm FWHM). Experimental investigations were performed to determine if the spectral properties of these outputs could be improved through the use of injection-locking techniques. A parametric study to determine the specific conditions under which the laser could be injection-locked was also carried out. Significant linewidth reduction to 0.0015nm) of the outputs was obtained through injection-locking but only at wavelengths near the peak lasing wavelength of the dye. It was found, however; that by inserting weakly dispersive tuning elements in the laser cavity, these narrow-linewidth outputs could be obtained over a wide (24nm) tuning range. Since the tuning elements had low insertion losses, the tunability of the output was obtained without sacrificing output pulse energy.

Neutral Details Associated with Emotional Events are Encoded: Evidence from a Cued Recall Paradigm

PubMed Central

Steinmetz, Katherine R. Mickley; Knight, Aubrey G.; Kensinger, Elizabeth A.

2015-01-01

Enhanced emotional memory often comes at the cost of memory for surrounding background information. Narrowed-encoding theories suggest that this is due to narrowed attention for emotional information at encoding, leading to impaired encoding of background information. Recent work has suggested that an encoding-based theory may be insufficient. Here, we examined whether cued recall – instead of previously used recognition memory tasks - would reveal evidence that non-emotional information associated with emotional information was effectively encoded. Participants encoded positive, negative, or neutral objects on neutral backgrounds. At retrieval, they were given either the item or the background as a memory cue and were asked to recall the associated scene element. Counter to narrowed-encoding theories, emotional items were more likely than neutral items to trigger recall of the associated background. This finding suggests that there is a memory trace of this contextual information and that emotional cues may facilitate retrieval of this information. PMID:26220708

Single-mode SOA-based 1kHz-linewidth dual-wavelength random fiber laser.

PubMed

Xu, Yanping; Zhang, Liang; Chen, Liang; Bao, Xiaoyi

2017-07-10

Narrow-linewidth multi-wavelength fiber lasers are of significant interests for fiber-optic sensors, spectroscopy, optical communications, and microwave generation. A novel narrow-linewidth dual-wavelength random fiber laser with single-mode operation, based on the semiconductor optical amplifier (SOA) gain, is achieved in this work for the first time, to the best of our knowledge. A simplified theoretical model is established to characterize such kind of random fiber laser. The inhomogeneous gain in SOA mitigates the mode competition significantly and alleviates the laser instability, which are frequently encountered in multi-wavelength fiber lasers with Erbium-doped fiber gain. The enhanced random distributed feedback from a 5km non-uniform fiber provides coherent feedback, acting as mode selection element to ensure single-mode operation with narrow linewidth of ~1kHz. The laser noises are also comprehensively investigated and studied, showing the improvements of the proposed random fiber laser with suppressed intensity and frequency noises.

Petrographic and geochemical investigation of magma chamber processes beneath small Quaternary volcanic centers between Mt. Jefferson and Mt. Hood volcanoes, Cascade Range Volcanic Arc

NASA Astrophysics Data System (ADS)

Cunningham, E.; Cribb, J. W.

2017-12-01

The northern Oregon Cascade Range has been dominated by andesite to rhyodacite lavas at both Mt. Jefferson (Conrey, 1991) and at Mt. Hood (Cribb and Barton, 1996) during the Quaternary period. Eruptive sequences at both Mt. Hood and Mt. Jefferson have been attributed to open-system mama mixing (Kent et al., 2010) (Ferrell et al., 2015), and the narrow range of lavas erupted at both centers has been derived from repeated cycles of magma mixing-fractionation (Cribb and Barton, 1996). This research examines major and trace element geochemistry as well as the petrographic characteristics of Clear Lake Butte (CLB), Pinhead Butte (PB), and Olallie Butte (OB), all of which are located between Mt. Hood and Mt. Jefferson, and have ben active in the Quaternary period. The research investigates whether the same type of open-system magma mixing known to have occurred at Mt. Hood and Mt. Jefferson has also occurred at CLB, PB, or OB, or whether those systems were closed to mixing and dominated by fractional crystallization. One of the main goals of this project is to highlight the similarities and differences exhibited by neighboring magmatic systems of similar age, but different scale. Disequilibrium textures observed in thin sections from CLB, OB, and PB suggest open-system magma mixing is likely occurring beneath all three buttes. This petrographic evidence includes plagioclase and pyroxene zoning, embayed margins, sieving, and reaction rims. Major element oxide trends at all three buttes are consistent with fractional crystallization, but show narrow concentrations and non-overlapping compositions between PB, CLB, and OB. All three buttes are characterized by narrow ranges of incompatible and compatible trace element concentrations. CLB, PB, and OB all exhibit LREE enrichment and lack significant HFSE depletions, with PB exhibiting greatest enrichment in REE.

Trace element distribution in waters of the northern catchment area of Lake Linneret, northern Israel

NASA Astrophysics Data System (ADS)

Sandler, A.; Brenner, I. B.; Halicz, L.

1988-02-01

Waters of the northern watershed of Lake Kineret, sampled during the period 1978 1983, were analyzed for their major and trace element contents. The trace element concentrations of the major water sources of the watershed (the Dan and Banias springs) represent background values. After emergence, the waters are subjected to human activity. In crossing the populated and cultivated Hula Basin in man-made canals, the major and trace element contents increase. In comparison to the trace element concentrations, those of the major elements have narrow ranges and small temporal fluctuations. Trace element concentrations varied by 3 orders of magnitude, and temporal variations were large but not neccessarily seasonal. Point sources of trace elements were urban effluents, fish pond wastes, and peat soil drainage. The trace element concentrations decrease in the waters of the last segment of the Jordan River. All measured trace elements were below the criteria levels established by regulatory agencies. Several, however, were of the same order of magnitude. Addition of wastes from enhanced recycling, and morphologic modification of the final course of the Jordan River could result in increase in the trace element concentrations in the water.

Resilience from coastal protection.

PubMed

Ewing, Lesley C

2015-10-28

Coastal areas are important residential, commercial and industrial areas; but coastal hazards can pose significant threats to these areas. Shoreline/coastal protection elements, both built structures such as breakwaters, seawalls and revetments, as well as natural features such as beaches, reefs and wetlands, are regular features of a coastal community and are important for community safety and development. These protection structures provide a range of resilience to coastal communities. During and after disasters, they help to minimize damages and support recovery; during non-disaster times, the values from shoreline elements shift from the narrow focus on protection. Most coastal communities have limited land and resources and few can dedicate scarce resources solely for protection. Values from shore protection can and should expand to include environmental, economic and social/cultural values. This paper discusses the key aspects of shoreline protection that influence effective community resilience and protection from disasters. This paper also presents ways that the economic, environmental and social/cultural values of shore protection can be evaluated and quantified. It presents the Coastal Community Hazard Protection Resilience (CCHPR) Index for evaluating the resilience capacity to coastal communities from various protection schemes and demonstrates the use of this Index for an urban beach in San Francisco, CA, USA. © 2015 The Author(s).

An Extensible Model and Analysis Framework

DTIC Science & Technology

2010-11-01

Eclipse or Netbeans Rich Client Platform (RCP). We call this the Triquetrum Project. Configuration files support narrower variability than Triquetrum/RCP...Triquetrum/RCP supports assembling in arbitrary ways. (12/08 presentation) 2. Prototyped OSGi component architecture for use with Netbeans and

Elemental Abundances in NGC 3516

NASA Technical Reports Server (NTRS)

Turner, T. J.; Kraemer, S. B.; Mushotzky, R. F.; George, I. M.; Gabel, J. R.

2003-01-01

We present Reflection Grating Spectrometer data from an XMM-Newton observation of the Seyfert 1 galaxy NGC 3516, taken while the continuum source was in an extremely low flux state. This observation offers a rare opportunity for a detailed study of emission from a Seyfert 1 galaxy as these are usually dominated by high nuclear continuum levels and heavy absorption. The spectrum shows numerous narrow emission lines (FWHM approximately less than 1300 kilometers per second) in the 0.3 - 2 keV range, including the H-like lines of C, N, and O and the He-like lines of N, O and Ne. The emission-line ratios and the narrow width of the radiative recombination continuum of CVI indicate that the gas is photoionized and of fairly low temperature (kT approximately less than 0.01 keV). The availability of emission lines from different elements for two iso-electronic sequences allows us to constrain the element abundances. These data show that the N lines are far stronger than would be expected from gas of solar abundances. Based on our photoionization models we find that nitrogen is overabundant in the central regions of the galaxy, compared to carbon, oxygen and neon by at least a factor of 2.5. We suggest that this is the result of secondary production of nitrogen in intermediate mass stars, and indicative of the history of star formation in NGC 3516.

Strengthening the Regression Discontinuity Design Using Additional Design Elements: A Within-Study Comparison

ERIC Educational Resources Information Center

Wing, Coady; Cook, Thomas D.

2013-01-01

The sharp regression discontinuity design (RDD) has three key weaknesses compared to the randomized clinical trial (RCT). It has lower statistical power, it is more dependent on statistical modeling assumptions, and its treatment effect estimates are limited to the narrow subpopulation of cases immediately around the cutoff, which is rarely of…

41 CFR 105-62.202 - Review of classified materials for declassification purposes.

Code of Federal Regulations, 2010 CFR

2010-07-01

... particularity or narrow the scope of the request, the element that received the request shall notify the... referral, it shall process the request in accordance with the requirements of this paragraph and, if so...) Based upon the outcome of the appeal, a reply shall be made to the person making the appeal that either...

Curriculum Elements of a Politically Liberal Education in a Developing Democracy

ERIC Educational Resources Information Center

Çelik, Rasit

2016-01-01

A previous study has justified the idea that a politically liberal conception of formal education can be applied in a developing democracy if such a society has reached a narrow overlapping consensus on its education system or modifies its education system from a minimally coercive perspective. This study further considers the fundamental question…

Non-proximity resonant tunneling in multi-core photonic band gap fibers: An efficient mechanism for engineering highly-selective ultra-narrow band pass splitters

NASA Astrophysics Data System (ADS)

Florous, Nikolaos J.; Saitoh, Kunimasa; Murao, Tadashi; Koshiba, Masanori; Skorobogatiy, Maksim

2006-05-01

The objective of the present investigation is to demonstrate the possibility of designing compact ultra-narrow band-pass filters based on the phenomenon of non-proximity resonant tunneling in multi-core photonic band gap fibers (PBGFs). The proposed PBGF consists of three identical air-cores separated by two defected air-holes which act as highly-selective resonators. With a fine adjustment of the design parameters associated with the resonant-air-holes, phase matching at two distinct wavelengths can be achieved, thus enabling very narrow-band resonant directional coupling between the input and the two output cores. The validation of the proposed design is ensured with an accurate PBGF analysis based on finite element modal and beam propagation algorithms. Typical characteristics of the proposed device over a single polarization are: reasonable short coupling length of 2.7 mm, dual bandpass transmission response at wavelengths of 1.339 and 1.357 μm, with corresponding full width at half maximum bandwidths of 1.2 nm and 1.1 nm respectively, and a relatively high transmission of 95% at the exact resonance wavelengths. The proposed ultra-narrow band-pass filter can be employed in various applications such as all-fiber bandpass/bandstop filtering and resonant sensors.

Non-proximity resonant tunneling in multi-core photonic band gap fibers: An efficient mechanism for engineering highly-selective ultra-narrow band pass splitters.

PubMed

Florous, Nikolaos J; Saitoh, Kunimasa; Murao, Tadashi; Koshiba, Masanori; Skorobogatiy, Maksim

2006-05-29

The objective of the present investigation is to demonstrate the possibility of designing compact ultra-narrow band-pass filters based on the phenomenon of non-proximity resonant tunneling in multi-core photonic band gap fibers (PBGFs). The proposed PBGF consists of three identical air-cores separated by two defected air-holes which act as highly-selective resonators. With a fine adjustment of the design parameters associated with the resonant-air-holes, phase matching at two distinct wavelengths can be achieved, thus enabling very narrow-band resonant directional coupling between the input and the two output cores. The validation of the proposed design is ensured with an accurate PBGF analysis based on finite element modal and beam propagation algorithms. Typical characteristics of the proposed device over a single polarization are: reasonable short coupling length of 2.7 mm, dual bandpass transmission response at wavelengths of 1.339 and 1.357 mum, with corresponding full width at half maximum bandwidths of 1.2 nm and 1.1 nm respectively, and a relatively high transmission of 95% at the exact resonance wavelengths. The proposed ultra-narrow band-pass filter can be employed in various applications such as all-fiber bandpass/bandstop filtering and resonant sensors.

High resolution collimator system for X-ray detector

DOEpatents

Eberhard, Jeffrey W.; Cain, Dallas E.

1987-01-01

High resolution in an X-ray computerized tomography (CT) inspection system is achieved by using a collimator/detector combination to limit the beam width of the X-ray beam incident on a detector element to the desired resolution width. In a detector such as a high pressure Xenon detector array, a narrow tapered collimator is provided above a wide detector element. The collimator slits have any desired width, as small as a few mils at the top, the slit width is easily controlled, and they are fabricated on standard machines. The slit length determines the slice thickness of the CT image.

Effects of laser source parameters on the generation of narrow band and directed laser ultrasound

NASA Technical Reports Server (NTRS)

Spicer, James B.; Deaton, John B., Jr.; Wagner, James W.

1992-01-01

Predictive and prescriptive modeling of laser arrays is performed to demonstrate the effects of the extension of array elements on laser array performance. For a repetitively pulsed laser source (the temporal laser array), efficient frequency compression is best achieved by detecting longitudinal waves off-epicenter in plates where the source size and shape directly influence the longitudinal wave shape and duration; the longitudinal array may be tailored for a given repetition frequency to yield efficient overtone energy compression into the fundamental frequency band. For phased arrays, apparent array directivity is heavily influenced by array element size.

Facile doping of anionic narrow-band-gap conjugated polyelectrolytes during dialysis.

PubMed

Mai, Cheng-Kang; Zhou, Huiqiong; Zhang, Yuan; Henson, Zachary B; Nguyen, Thuc-Quyen; Heeger, Alan J; Bazan, Guillermo C

2013-12-02

PCPDTBTSO3 K, an anionic, narrow-band-gap conjugated polyelectrolyte, was found to be doped after dialysis. The proposed doping mechanism involves protonation of the polymer backbone, followed by electron transfer from a neutral chain, to generate radical cations, which are stabilized by the pendant sulfonate anions. Formation of polarons is supported by spectroscopy and electrical-conductivity measurements. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Fault tolerance in space-based digital signal processing and switching systems: Protecting up-link processing resources, demultiplexer, demodulator, and decoder

NASA Technical Reports Server (NTRS)

Redinbo, Robert

1994-01-01

Fault tolerance features in the first three major subsystems appearing in the next generation of communications satellites are described. These satellites will contain extensive but efficient high-speed processing and switching capabilities to support the low signal strengths associated with very small aperture terminals. The terminals' numerous data channels are combined through frequency division multiplexing (FDM) on the up-links and are protected individually by forward error-correcting (FEC) binary convolutional codes. The front-end processing resources, demultiplexer, demodulators, and FEC decoders extract all data channels which are then switched individually, multiplexed, and remodulated before retransmission to earth terminals through narrow beam spot antennas. Algorithm based fault tolerance (ABFT) techniques, which relate real number parity values with data flows and operations, are used to protect the data processing operations. The additional checking features utilize resources that can be substituted for normal processing elements when resource reconfiguration is required to replace a failed unit.

Supporting Digital Literacy across the Curriculum through Blended Support: A Pilot Project Report

ERIC Educational Resources Information Center

Smith, Samara

2014-01-01

This article describes the Collaborative Media Center pilot at SUNY Old Westbury, a digital literacy project with the aim of narrowing the digital divide at the College by embedding digital projects across the curriculum. The article explains how the Center supported students in four linked courses to create digital projects. Assessment data and…

Prevalence of Extracranial Venous Narrowing on Magnetic Resonance Venography Is Similar in People With Multiple Sclerosis, Their Siblings, and Unrelated Healthy Controls: A Blinded, Case-Control Study.

PubMed

Martin, Nancy; Traboulsee, Anthony L; Machan, Lindsay; Klass, Darren; Ellchuk, Tasha; Zhao, Yinshan; Knox, Katherine B; Kopriva, David; Lala, Shantilal; Nickel, Darren; Otani, Robert; Perera, Warren R; Rauscher, Alexander; Sadovnick, A Dessa; Szkup, Peter; Li, David K

2017-05-01

The study sought to assess and compare the prevalence of narrowing of the major extracranial veins in subjects with multiple sclerosis and controls, and to assess the sensitivity and specificity of magnetic resonance venography (MRV) for describing extracranial venous narrowing as it applies to the chronic cerebrospinal venous insufficiency theory, using catheter venography (CV) as the gold standard. The jugular and azygos veins were assessed with time-of-flight MRV in this assessor-blinded, case-control study of subjects with multiple sclerosis, their unaffected siblings, and unrelated controls. The veins were evaluated by diameter and area, and compared with CV. Collateral vessels were also analyzed for maximal diameter, as a potential indicator of compensatory flow. A high prevalence of extracranial venous narrowing was demonstrated in all study groups, collectively up to 84% by diameter criteria and 90% by area, with no significant difference between the groups when assessed independently (P = .34 and .63, respectively). There was high interobserver variability in the reporting of vessel narrowing (kappa = 0.32), and poor vessel per vessel correlation between narrowing on MRV and CV (kappa = 0.064). Collateral neck veins demonstrated no convincing difference in maximum size or correlation with jugular narrowing. There is a high prevalence of narrowing of the major extracranial veins on MRV in all 3 study groups, with no significant difference between them. These findings do not support the chronic cerebrospinal venous insufficiency theory. Although MRV has shown a high sensitivity for identifying venous narrowing, time-of-flight imaging demonstrates poor interobserver agreement and poor specificity when compared with the gold standard CV. Copyright © 2016 Canadian Association of Radiologists. Published by Elsevier Inc. All rights reserved.

Concerted formation of macromolecular Suppressor–mutator transposition complexes

PubMed Central

Raina, Ramesh; Schläppi, Michael; Karunanandaa, Balasulojini; Elhofy, Adam; Fedoroff, Nina

1998-01-01

Transposition of the maize Suppressor–mutator (Spm) transposon requires two element-encoded proteins, TnpA and TnpD. Although there are multiple TnpA binding sites near each element end, binding of TnpA to DNA is not cooperative, and the binding affinity is not markedly affected by the number of binding sites per DNA fragment. However, intermolecular complexes form cooperatively between DNA fragments with three or more TnpA binding sites. TnpD, itself not a sequence-specific DNA-binding protein, binds to TnpA and stabilizes the TnpA–DNA complex. The high redundancy of TnpA binding sites at both element ends and the protein–protein interactions between DNA-bound TnpA complexes and between these and TnpD imply a concerted transition of the element from a linear to a protein crosslinked transposition complex within a very narrow protein concentration range. PMID:9671711

Age-resolved chemistry of red giants in the solar neighbourhood

NASA Astrophysics Data System (ADS)

Feuillet, Diane K.; Bovy, Jo; Holtzman, Jon; Weinberg, David H.; García-Hernández, D.; Hearty, Fred R.; Majewski, Steven R.; Roman-Lopes, Alexandre; Rybizki, Jan; Zamora, Olga

2018-06-01

In the age of high-resolution spectroscopic stellar surveys of the Milky Way, the number of stars with detailed abundances of multiple elements is rapidly increasing. These elemental abundances are directly influenced by the evolutionary history of the Galaxy, but this can be difficult to interpret without an absolute timeline of the abundance enrichment. We present age-abundance trends for [M/H], [α/M], and 17 individual elements using a sample of 721 solar neighbourhood Hipparcos red giant stars observed by Apache Point Observatory Galactic Evolution Experiment. These age trends are determined through a Bayesian hierarchical modelling method presented by Feuillet et al. We confirm that the [α/M]-age relation in the solar neighbourhood is steep and relatively narrow (0.20 dex age dispersion), as are the [O/M]-age and [Mg/M]-age relations. The age trend of [C/N] is steep and smooth, consistent with stellar evolution. The [M/H]-age relation has a mean age dispersion of 0.28 dex and a complex overall structure. The oldest stars in our sample are those with the lowest and highest metallicities, while the youngest stars are those with solar metallicity. These results provide strong constraints on theoretical models of Galactic chemical evolution (GCE). We compare them to the predictions of one-zone GCE models and multizone mixtures, both analytic and numerical. These comparisons support the hypothesis that the solar neighbourhood is composed of stars born at a range of Galactocentric radii, and that the most metal-rich stars likely migrated from a region with earlier and more rapid star formation such as the inner Galaxy.

Isolation and Distinctiveness in the Design of E-Learning Systems Influence User Preferences

ERIC Educational Resources Information Center

Al-Samarraie, Hosam; Selim, Hassan; Teo, Timothy; Zaqout, Fahed

2017-01-01

When faced with excessive detail in an online environment, typical users have difficulty processing all the elements of representation. This in turn creates cognitive overload, which narrows the user's focus to a few select items. In the context of e-learning, we translated this aspect as the learner's demand for a system that facilitates the…

Stabilizing an optoelectronic microwave oscillator with photonic filters

NASA Technical Reports Server (NTRS)

Strekalov, D.; Aveline, D.; Yu, N.; Thompson, R.; Matsko, A. B.; Maleki, L.

2003-01-01

This paper compares methods of active stabilization of an optoelectronic microwave oscillator (OEO) based on insertion of a source of optical group delay into an OEO loop. The performance of an OEO stabilized with either a high- optical cavity or an atomic cell is analyzed. We show that the elements play a role of narrow-band microwave filters improving an OEO stability.

SN2005da: A Spectroscopic and Photometric Analysis of a Peculiar Type Ic Supernova

NASA Astrophysics Data System (ADS)

Williamson, Jacob

2017-12-01

Core collapse supernovae are an important class of objects in stellar evolution research as they are the final life stage of high mass stars. Supernovae in general are classified into several spectral types; this paper explores SN 2005da, classified as a Type Ic, meaning it lacks hydrogen and helium lines. The supernova was originally classified as a broad-lined Type Ic (Type Ic-BL), with expansion velocities near maximum light greater than or approximately equal to 15000 km/s. However, some of the elements present in the spectrum, namely carbon and oxygen, have narrower lines (FWHM approximately equal to 2300 km/s) than other elements, indicating an interaction with a previously ejected envelope. The supernova is also found to have a decay time, with a change in magnitude over 15 days following maximum light of about 1.4 magnitudes, that is significantly faster than typical Type Ic or Ic-BL. This is more akin to a rarer object type known as a Type Ibn, although it lacks the characteristic narrow helium lines of this type. Therefore, SN 2005da appears to be unlike known examples of Type Ic supernovae.

Broadband implementation of coprime linear microphone arrays for direction of arrival estimation.

PubMed

Bush, Dane; Xiang, Ning

2015-07-01

Coprime arrays represent a form of sparse sensing which can achieve narrow beams using relatively few elements, exceeding the spatial Nyquist sampling limit. The purpose of this paper is to expand on and experimentally validate coprime array theory in an acoustic implementation. Two nested sparse uniform linear subarrays with coprime number of elements ( M and N) each produce grating lobes that overlap with one another completely in just one direction. When the subarray outputs are combined it is possible to retain the shared beam while mostly canceling the other superfluous grating lobes. In this way a small number of microphones ( N+M-1) creates a narrow beam at higher frequencies, comparable to a densely populated uniform linear array of MN microphones. In this work beampatterns are simulated for a range of single frequencies, as well as bands of frequencies. Narrowband experimental beampatterns are shown to correspond with simulated results even at frequencies other than the arrays design frequency. Narrowband side lobe locations are shown to correspond to the theoretical values. Side lobes in the directional pattern are mitigated by increasing bandwidth of analyzed signals. Direction of arrival estimation is also implemented for two simultaneous noise sources in a free field condition.

When the Japanese Bombed the Huertgen Forest: How the Army’s Investigation of Pearl Harbor Influenced the Outcome of the Huertgen Forest, Major General Leonard T. Gerow and His Command of V Corps from 1943-1945

DTIC Science & Technology

2011-05-19

only a narrow supply line that passed along a narrow one-lane path called the Kall Trail.13 The Germans mounted fierce counter-attacks well supported...Bradley. New York: Ballantine Books, 1971 . ________. West Wall: The Battle For Hitler’s Siegfried Line. Conshohocken, PA.: Da Capo Press, 2000

Development of a Fitness-for-Duty Assessment Battery for Recovering Dismounted Warriors

DTIC Science & Technology

2014-04-07

pressure waves and can include injury to internal organs due to air pressure; secondary effects are due to objects that strike the victim, and tertiary...battery with a narrow stance ( knee to heel ) 3 lane configuration 1 target at a time, 10 targets total, targets appear at 75m; Targets appear at...balance himself due to the narrow base of support ( knee -to- heel ). 23 Figure 12. Phase 2: Mean (±SE

Importance of Resolving the Spectral Support of Beam-plasma Instabilities in Simulations

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

Shalaby, Mohamad; Broderick, Avery E.; Chang, Philip

2017-10-20

Many astrophysical plasmas are prone to beam-plasma instabilities. For relativistic and dilute beams, the spectral support of the beam-plasma instabilities is narrow, i.e., the linearly unstable modes that grow with rates comparable to the maximum growth rate occupy a narrow range of wavenumbers. This places stringent requirements on the box-sizes when simulating the evolution of the instabilities. We identify the implied lower limits on the box size imposed by the longitudinal beam plasma instability, i.e., typically the most stringent condition required to correctly capture the linear evolution of the instabilities in multidimensional simulations. We find that sizes many orders ofmore » magnitude larger than the resonant wavelength are typically required. Using one-dimensional particle-in-cell simulations, we show that the failure to sufficiently resolve the spectral support of the longitudinal instability yields slower growth and lower levels of saturation, potentially leading to erroneous physical conclusion.« less

Postural Control During Cascade Ball Juggling: Effects of Expertise and Base of Support.

PubMed

Rodrigues, Sérgio T; Polastri, Paula F; Gotardi, Gisele C; Aguiar, Stefane A; Mesaros, Marcelo R; Pestana, Mayara B; Barbieri, Fabio A

2016-08-01

Cascade ball juggling is a complex perceptual motor skill which requires efficient postural stabilization. The aim of this study was to investigate effects of experience (expert and intermediate groups) and foot distance (wide and narrow stances) on body sway of jugglers during three ball cascade juggling. A total of 10 expert jugglers and 11 intermediate jugglers participated in this study. Participants stood barefoot on the force plate (some participants wore a gaze tracking system), with feet maintained in wide and narrow conditions and performed three 40-seconds trials of the three-ball juggling task. Dependent variables were sway mean velocity, amplitude, mean frequency, number of ball cycles, fixation number, mean duration and its variability, and area of gaze displacement. Two-way analyses of variance with factors for group and condition were conducted. Experts' body sway was characterized by lower velocity and smaller amplitude as compared to intermediate group. Interestingly, the more challenging (narrow) basis of support caused significant attenuation in body sway only for the intermediate group. These data suggest that expertise in cascade juggling was associated with refined postural control. © The Author(s) 2016.

Application of closed-form solutions to a mesh point field in silicon solar cells

NASA Technical Reports Server (NTRS)

Lamorte, M. F.

1985-01-01

A computer simulation method is discussed that provides for equivalent simulation accuracy, but that exhibits significantly lower CPU running time per bias point compared to other techniques. This new method is applied to a mesh point field as is customary in numerical integration (NI) techniques. The assumption of a linear approximation for the dependent variable, which is typically used in the finite difference and finite element NI methods, is not required. Instead, the set of device transport equations is applied to, and the closed-form solutions obtained for, each mesh point. The mesh point field is generated so that the coefficients in the set of transport equations exhibit small changes between adjacent mesh points. Application of this method to high-efficiency silicon solar cells is described; and the method by which Auger recombination, ambipolar considerations, built-in and induced electric fields, bandgap narrowing, carrier confinement, and carrier diffusivities are treated. Bandgap narrowing has been investigated using Fermi-Dirac statistics, and these results show that bandgap narrowing is more pronounced and that it is temperature-dependent in contrast to the results based on Boltzmann statistics.

The Role of Crustal Strength in Controlling Magmatism and Melt Chemistry During Rifting and Breakup

NASA Astrophysics Data System (ADS)

Armitage, John J.; Petersen, Kenni D.; Pérez-Gussinyé, Marta

2018-02-01

The strength of the crust has a strong impact on the evolution of continental extension and breakup. Strong crust may promote focused narrow rifting, while wide rifting might be due to a weaker crustal architecture. The strength of the crust also influences deeper processes within the asthenosphere. To quantitatively test the implications of crustal strength on the evolution of continental rift zones, we developed a 2-D numerical model of lithosphere extension that can predict the rare Earth element (REE) chemistry of erupted lava. We find that a difference in crustal strength leads to a different rate of depletion in light elements relative to heavy elements. By comparing the model predictions to rock samples from the Basin and Range, USA, we can demonstrate that slow extension of a weak continental crust can explain the observed depletion in melt chemistry. The same comparison for the Main Ethiopian Rift suggests that magmatism within this narrow rift zone can be explained by the localization of strain caused by a strong lower crust. We demonstrate that the slow extension of a strong lower crust above a mantle of potential temperature of 1,350 °C can fit the observed REE trends and the upper mantle seismic velocity for the Main Ethiopian Rift. The thermo-mechanical model implies that melt composition could provide quantitative information on the style of breakup and the initial strength of the continental crust.

Whale phylogeny and rapid radiation events revealed using novel retroposed elements and their flanking sequences.

PubMed

Chen, Zhuo; Xu, Shixia; Zhou, Kaiya; Yang, Guang

2011-10-27

A diversity of hypotheses have been proposed based on both morphological and molecular data to reveal phylogenetic relationships within the order Cetacea (dolphins, porpoises, and whales), and great progress has been made in the past two decades. However, there is still some controversy concerning relationships among certain cetacean taxa such as river dolphins and delphinoid species, which needs to be further addressed with more markers in an effort to address unresolved portions of the phylogeny. An analysis of additional SINE insertions and SINE-flanking sequences supported the monophyly of the order Cetacea as well as Odontocete, Delphinoidea (Delphinidae + Phocoenidae + Mondontidae), and Delphinidae. A sister relationship between Delphinidae and Phocoenidae + Mondontidae was supported, and members of classical river dolphins and the genera Tursiops and Stenella were found to be paraphyletic. Estimates of divergence times revealed rapid divergences of basal Odontocete lineages in the Oligocene and Early Miocene, and a recent rapid diversification of Delphinidae in the Middle-Late Miocene and Pliocene within a narrow time frame. Several novel SINEs were found to differentiate Delphinidae from the other two families (Monodontidae and Phocoenidae), whereas the sister grouping of the latter two families with exclusion of Delphinidae was further revealed using the SINE-flanking sequences. Interestingly, some anomalous PCR amplification patterns of SINE insertions were detected, which can be explained as the result of potential ancestral SINE polymorphisms and incomplete lineage sorting. Although a few loci were potentially anomalous, this study demonstrated that the SINE-based approach is a powerful tool in phylogenetic studies. Identifying additional SINE elements that resolve the relationships in the superfamily Delphinoidea and family Delphinidae will be important steps forward in completely resolving cetacean phylogenetic relationships in the future.

Whale phylogeny and rapid radiation events revealed using novel retroposed elements and their flanking sequences

PubMed Central

2011-01-01

Background A diversity of hypotheses have been proposed based on both morphological and molecular data to reveal phylogenetic relationships within the order Cetacea (dolphins, porpoises, and whales), and great progress has been made in the past two decades. However, there is still some controversy concerning relationships among certain cetacean taxa such as river dolphins and delphinoid species, which needs to be further addressed with more markers in an effort to address unresolved portions of the phylogeny. Results An analysis of additional SINE insertions and SINE-flanking sequences supported the monophyly of the order Cetacea as well as Odontocete, Delphinoidea (Delphinidae + Phocoenidae + Mondontidae), and Delphinidae. A sister relationship between Delphinidae and Phocoenidae + Mondontidae was supported, and members of classical river dolphins and the genera Tursiops and Stenella were found to be paraphyletic. Estimates of divergence times revealed rapid divergences of basal Odontocete lineages in the Oligocene and Early Miocene, and a recent rapid diversification of Delphinidae in the Middle-Late Miocene and Pliocene within a narrow time frame. Conclusions Several novel SINEs were found to differentiate Delphinidae from the other two families (Monodontidae and Phocoenidae), whereas the sister grouping of the latter two families with exclusion of Delphinidae was further revealed using the SINE-flanking sequences. Interestingly, some anomalous PCR amplification patterns of SINE insertions were detected, which can be explained as the result of potential ancestral SINE polymorphisms and incomplete lineage sorting. Although a few loci were potentially anomalous, this study demonstrated that the SINE-based approach is a powerful tool in phylogenetic studies. Identifying additional SINE elements that resolve the relationships in the superfamily Delphinoidea and family Delphinidae will be important steps forward in completely resolving cetacean phylogenetic relationships in the future. PMID:22029548

Investigation of single lateral mode for 852nm diode lasers with ridge waveguide design

NASA Astrophysics Data System (ADS)

Liu, Chu; Guan, Baolu; Mi, Guoxin; Liao, Yiru; Liu, Zhenyang; Li, Jianjun; Xu, Chen

2016-11-01

852nm Narrow linewidth lasers can be widely used in the field of ultra-fine spectrum measurement, Cs atomic clock control, satellite and optical fiber communication and so on. Furthermore, the stability of the single lateral mode is a very important condition to guarantee the narrow linewidth lasers. Here we investigate experimentally the influence of the narrow ridge structure and asymmetrical waveguide design on the stability single lateral mode of an 852nm diode laser. According to the waveguide theoretical analysis, ridge mesa etch depth (Δη , related to the refractive index difference of parallel to the junction) and ridge mesa width (the narrower the more control force to low order mode) are the main elements for lateral modes. In this paper, we designed different structures to investigate and verify major factors for lateral mode by experiment, and to confirm our thought. Finally, the 5μm mesa ridge laser, 800nm etch depth, with groove structure obtains excellent steady single lateral mode output by 150mA operating current and 30°C temperature. The optical spectrum FWHM is 0.5nm and side mode suppression ratio is 27dBm with uncoated. The laser with 1mm cavity length showed the threshold current of 50mA, a lasing wavelength of λ = 852.6nm, slope efficiency of above 0.7mW/mA. We accomplished single lateral mode of ridge waveguide edge-emitting lasers which can also be used as a laser source in the ultra-narrow linewidth external cavity laser system.

A Six-Node Curved Triangular Element and a Four-Node Quadrilateral Element for Analysis of Laminated Composite Aerospace Structures

NASA Technical Reports Server (NTRS)

Martin, C. Wayne; Breiner, David M.; Gupta, Kajal K. (Technical Monitor)

2004-01-01

Mathematical development and some computed results are presented for Mindlin plate and shell elements, suitable for analysis of laminated composite and sandwich structures. These elements use the conventional 3 (plate) or 5 (shell) nodal degrees of freedom, have no communicable mechanisms, have no spurious shear energy (no shear locking), have no spurious membrane energy (no membrane locking) and do not require arbitrary reduction of out-of-plane shear moduli or under-integration. Artificial out-of-plane rotational stiffnesses are added at the element level to avoid convergence problems or singularity due to flat spots in shells. This report discusses a 6-node curved triangular element and a 4-node quadrilateral element. Findings show that in regular rectangular meshes, the Martin-Breiner 6-node triangular curved shell (MB6) is approximately equivalent to the conventional 8-node quadrilateral with integration. The 4-node quadrilateral (MB4) has very good accuracy for a 4-node element, and may be preferred in vibration analysis because of narrower bandwidth. The mathematical developments used in these elements, those discussed in the seven appendices, have been applied to elements with 3, 4, 6, and 10 nodes and can be applied to other nodal configurations.

Millimeter-wave/infrared rectenna development at Georgia Tech

NASA Technical Reports Server (NTRS)

Gouker, Mark A.

1989-01-01

The key design issues of the Millimeter Wave/Infrared (MMW/IR) monolithic rectenna have been resolved. The work at Georgia Tech in the last year has focused on increasing the power received by the physically small MMW rectennas in order to increase the rectification efficiency. The solution to this problem is to place a focusing element on the back side of the substrate. The size of the focusing element can be adjusted to help maintain the optimum input power density not only for different power densities called for in various mission scenarios, but also for the nonuniform power density profile of a narrow EM-beam.

Aquifer characteristics near cuestas and their relation to rock tensile strength

USGS Publications Warehouse

Morin, Roger H.; Schulz, William; LoCoco, James

2010-01-01

Along the northeast coast of North America, extensional tectonic processes have generated lithologic and topographic features that are common to several rift basins. A cap of igneous rock overlies sedimentary rock to form a cuesta with both rock types exposed along a steep ridge flank. Field studies investigating the near‐surface hydrogeologic properties of the caprocks at several of these sites have reported a narrow range of results; some fractured rocks form modest aquifers whereas others do not. To examine this behavior in terms of geomechanical responses to gravitational stresses imposed near ridges, a finite‐element model is presented that incorporates the geometry of a ridge‐valley configuration and its major structural elements. Model simulations reflect the effects of a lack of buttressing along free faces and a contrast in Poisson's ratios between the superposed igneous and sedimentary rocks. Three‐dimensional Mohr's circles are constructed from principal stress magnitudes and directions to evaluate the response of individual fracture planes to this stress state. Results depict a predominantly tensional stress environment where numerous pre‐existing fractures may be favorably aligned for opening and enhanced caprock permeability. However, the lack of conclusive field evidence to support this hypothesis suggests that the in situ tensile strength of the fractured rock mass is substantial enough to resist failure by shear or dilation, and that critically‐stressed fracture planes do not convey large volumes of groundwater in ridge‐valley settings.

Spatial distribution of airway wall displacements during breathing and bronchoconstriction measured by ultrasound elastography using finite element image registration.

PubMed

Harvey, Brian C; Lutchen, Kenneth R; Barbone, Paul E

2017-03-01

With every breath, the airways within the lungs are strained. This periodic stretching is thought to play an important role in determining airway caliber in health and disease. Particularly, deep breaths can mitigate excessive airway narrowing in healthy subjects, but this beneficial effect is absent in asthmatics, perhaps due to an inability to stretch the airway smooth muscle (ASM) embedded within an airway wall. The heterogeneous composition throughout an airway wall likely modulates the strain felt by the ASM but the magnitude of ASM strain is difficult to measure directly. In this study, we optimized a finite element image registration method to measure the spatial distribution of displacements and strains throughout an airway wall during pressure inflation within the physiological breathing range before and after induced narrowing with acetylcholine (ACh). The method was shown to be repeatable, and displacements estimated from different image sequences of the same deformation agreed to within 5.3μm (0.77%). We found the magnitude and spatial distribution of displacements were radially and longitudinally heterogeneous. The region in the middle layer of the airway experienced the largest radial strain due to a transmural pressure (Ptm) increase simulating tidal breathing and a deep inspiration (DI), while the region containing the ASM (i.e., closest to the lumen) strained least. During induced narrowing with ACh, we observed temporal longitudinal heterogeneity of the airway wall. After constriction, the displacements and strain are much smaller than the relaxed airway and the pattern of strains changed, suggesting the airway stiffened heterogeneously. Copyright © 2016 Elsevier B.V. All rights reserved.

Selective CO2 conversion to formate in water using a CZTS photocathode modified with a ruthenium complex polymer.

PubMed

Arai, Takeo; Tajima, Shin; Sato, Shunsuke; Uemura, Keiko; Morikawa, Takeshi; Kajino, Tsutomu

2011-12-21

Highly selective photoelectrochemical CO(2) reduction (>80% selectivity) in water was successfully achieved by combining Cu(2)ZnSnS(4) (CZTS) with a metal-complex electrocatalyst. CZTS, a sulfide semiconductor that possesses a narrow band gap and consists of earth-abundant elements, is demonstrated to be a candidate photoabsorber for a CO(2) reduction hybrid photocatalyst.

A novel, multiplexed, probe-based quantitative PCR assay for the soybean root- and stem-rot pathogen, Phytophthora sojae, utilizes its transposable element

USDA-ARS?s Scientific Manuscript database

Phytophthora root rot of soybean (Glycine max Merr.) is caused by the oomycete Phytophthora sojae (Kaufm. and Gerd.). P. sojae has a narrow host range, consisting primarily of soybean, and it is a serious pathogen worldwide. It exists in root and stem tissues as mycelium, wherein it can form oospo...

High ionic strength narrows the population of sites participating in protein ion-exchange adsorption: A single-molecule study

PubMed Central

Kisley, Lydia; Chen, Jixin; Mansur, Andrea P.; Dominguez-Medina, Sergio; Kulla, Eliona; Kang, Marci; Shuang, Bo; Kourentzi, Katerina; Poongavanam, Mohan-Vivekanandan; Dhamane, Sagar; Willson, Richard C.; Landes, Christy F.

2014-01-01

The retention and elution of proteins in ion-exchange chromatography is routinely controlled by adjusting the mobile phase salt concentration. It has repeatedly been observed, as judged from adsorption isotherms, that the apparent heterogeneity of adsorption is lower at more-eluting, higher ionic strength. Here, we present an investigation into the mechanism of this phenomenon using a single-molecule, super-resolution imaging technique called motion-blur Points Accumulation for Imaging in Nanoscale Topography (mbPAINT). We observed that the number of functional adsorption sites was smaller at high ionic strength and that these sites had reduced desorption kinetic heterogeneity, and thus narrower predicted elution profiles, for the anion-exchange adsorption of α-lactalbumin on an agarose-supported, clustered-charge ligand stationary phase. Explanations for the narrowing of the functional population such as inter-protein interactions and protein or support structural changes were investigated through kinetic analysis, circular dichroism spectroscopy, and microscopy of agarose microbeads, respectively. The results suggest the reduction of heterogeneity is due to both electrostatic screening between the protein and ligand and tuning the steric availability within the agarose support. Overall, we have shown that single molecule spectroscopy can aid in understanding the influence of ionic strength on the population of functional adsorbent sites participating in the ion-exchange chromatographic separation of proteins. PMID:24751557

78 FR 51277 - Endangered and Threatened Wildlife and Plants; Determination of Endangered Species Status for the...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-20

... and materials received, as well as supporting documentation used in preparing this final rule is... Salado salamanders; however, molecular evidence strongly supports that there is a high level of... al. 2001, p. 268). Habitat Each species inhabits water of high quality with a narrow range of...

The Future of Educational Research: Has Nietzsche Led the Way?

ERIC Educational Resources Information Center

Moran, Paul

2016-01-01

This brief editorial suggests that educational research has allowed itself to be constructed in a very narrow way, that seeks, sometimes despite itself, even when the research is of excellent quality, to support the underlying neoliberal values and practices that support its current educational regime. Rather than lamenting this state of affairs,…

Boundary Kernel Estimation of the Two Sample Comparison Density Function

DTIC Science & Technology

1989-05-01

not for the understand- ing, love, and steadfast support of my wife, Catheryn . She supported my move to statistics a mere fortnight after we were...school one learns things of a narrow and technical nature; 0 Catheryn has shown me much of what is fundamentally true and important in this world. To her

Superconducting coil and method of stress management in a superconducting coil

DOEpatents

McIntyre, Peter M.; Shen, Weijun; Diaczenko, Nick; Gross, Dan A.

1999-01-01

A superconducting coil (12) having a plurality of superconducting layers (18) is provided. Each superconducting layer (18) may have at least one superconducting element (20) which produces an operational load. An outer support structure (24) may be disposed outwardly from the plurality of layers (18). A load transfer system (22) may be coupled between at least one of the superconducting elements (20) and the outer support structure (24). The load transfer system (22) may include a support matrix structure (30) operable to transfer the operational load from the superconducting element (20) directly to the outer support structure (24). A shear release layer (40) may be disposed, in part, between the superconducting element (20) and the support matrix structure (30) for relieving a shear stress between the superconducting element (20) and the support matrix structure (30). A compliant layer (42) may also be disposed, in part, between the superconducting element (20) and the support matrix structure (30) for relieving a compressive stress on the superconducting element (20).

Leber Congenital Amaurosis

MedlinePlus

... Campaign to End Blindness Other Ways to Fight Blindness Corporate Support Volunteer Take Action You are here ... become narrow and constricted. A variety of pigmentary (color) changes can also occur in the retinal pigment ...

Hot gas cross flow filtering module

DOEpatents

Lippert, Thomas E.; Ciliberti, David F.

1988-01-01

A filter module for use in filtering particulates from a high temperature gas has a central gas duct and at least one horizontally extending support mount affixed to the duct. The support mount supports a filter element thereon and has a chamber therein, which communicates with an inner space of the duct through an opening in the wall of the duct, and which communicates with the clean gas face of the filter element. The filter element is secured to the support mount over an opening in the top wall of the support mount, with releasable securement provided to enable replacement of the filter element when desired. Ceramic springs may be used in connection with the filter module either to secure a filter element to a support mount or to prevent delamination of the filter element during blowback.

Narrow linewidth operation of a spectral beam combined diode laser bar.

PubMed

Zhu, Zhanda; Jiang, Menghua; Cheng, Siqi; Hui, Yongling; Lei, Hong; Li, Qiang

2016-04-20

Our experiment is expected to provide an approach for realizing ultranarrow linewidth for a spectral beam combined diode laser bar. The beams of a diode laser bar are combined in a fast axis after a beam transformation system. With the help of relay optics and a transform lens with a long focal length of 1.5 m, the whole wavelength of a spectral combined laser bar can be narrowed down to 0.48 nm from more than 10 nm. We have achieved 56.7 W cw from a 19-element single bar with an M² of 1.4  (in horizontal direction)×11.6  (in vertical direction). These parameters are good evidence that all the beams from the diode laser bar are combined together to increase the brightness.

Active full-shell grazing-incidence optics

NASA Astrophysics Data System (ADS)

Roche, Jacqueline M.; Elsner, Ronald F.; Ramsey, Brian D.; O'Dell, Stephen L.; Kolodziejczak, Jeffrey J.; Weisskopf, Martin C.; Gubarev, Mikhail V.

2016-09-01

MSFC has a long history of developing full-shell grazing-incidence x-ray optics for both narrow (pointed) and wide field (surveying) applications. The concept presented in this paper shows the potential to use active optics to switch between narrow and wide-field geometries, while maintaining large effective area and high angular resolution. In addition, active optics has the potential to reduce errors due to mounting and manufacturing lightweight optics. The design presented corrects low spatial frequency error and has significantly fewer actuators than other concepts presented thus far in the field of active x-ray optics. Using a finite element model, influence functions are calculated using active components on a full-shell grazing-incidence optic. Next, the ability of the active optic to effect a change of optical prescription and to correct for errors due to manufacturing and mounting is modeled.

The development of a tunable, single-frequency ultraviolet laser source for UV filtered Rayleigh scattering

NASA Technical Reports Server (NTRS)

Finkelstein, N.; Gambogi, J.; Lempert, Walter R.; Miles, Richard B.; Rines, G. A.; Finch, A.; Schwarz, R. A.

1995-01-01

We present the development of a flexible, high power, narrow line width, tunable ultraviolet source for diagnostic application. By frequency tripling the output of a pulsed titanium-sapphire laser, we achieve broadly tunable (227-360 nm) ultraviolet light with high quality spatial and spectral resolution. We also present the characterization of a mercury vapor cell which provides a narrow band, sharp edge absorption filter at 253.7 nm. These two components form the basis for the extension of the Filtered Rayleigh Scattering technique into the ultraviolet. The UV-FRS system is comprised of four pieces: a single frequency, cw tunable Ti:Sapphire seeding source; a high-powered pulsed Ti:Sapphire oscillator; a third harmonic generator system; and an atomic mercury vapor filter. In this paper we discuss the development and characterization of each of these elements.

Single steady frequency and narrow-linewidth external-cavity semiconductor laser

NASA Astrophysics Data System (ADS)

Zhao, Weirui; Jiang, Pengfei; Xie, Fuzeng

2003-11-01

A single longitudinal mode and narrow line width external cavity semiconductor laser is proposed. It is constructed with a semiconductor laser, collimator, a flame grating, and current and temperature control systems. The one facet of semiconductor laser is covered by high transmission film, and another is covered by high reflection film. The flame grating is used as light feedback element to select the mode of the semiconductor laser. The temperature of the constructed external cavity semiconductor laser is stabilized in order of 10-3°C by temperature control system. The experiments have been carried out and the results obtained - the spectral line width of this laser is compressed to be less than 1.4MHz from its original line-width of more than 1200GHz and the output stability (including power and mode) is remarkably enhanced.

Active Full-Shell Grazing-Incidence Optics

NASA Technical Reports Server (NTRS)

Davis, Jacqueline M.; Elsner, Ronald F.; Ramsey, Brian D.; O'Dell, Stephen L.; Kolodziejczak, Jeffery; Weisskopf, Martin C.; Gubarev, Mikhail V.

2016-01-01

MSFC has a long history of developing full-shell grazing-incidence x-ray optics for both narrow (pointed) and wide field (surveying) applications. The concept presented in this paper shows the potential to use active optics to switch between narrow and wide-field geometries, while maintaining large effective area and high angular resolution. In addition, active optics has the potential to reduce errors due to mounting and manufacturing lightweight optics. The design presented corrects low spatial frequency error and has significantly fewer actuators than other concepts presented thus far in the field of active x-ray optics. Using a finite element model, influence functions are calculated using active components on a full-shell grazing-incidence optic. Next, the ability of the active optic to effect a change of optical prescription and to correct for errors due to manufacturing and mounting is modeled.

Laminar-Turbulent Transition Behind Discrete Roughness Elements in a High-Speed Boundary Layer

NASA Technical Reports Server (NTRS)

Choudhari, Meelan M.; Li, Fei; Wu, Minwei; Chang, Chau-Lyan; Edwards, Jack R., Jr.; Kegerise, Michael; King, Rudolph

2010-01-01

Computations are performed to study the flow past an isolated roughness element in a Mach 3.5, laminar, flat plate boundary layer. To determine the effects of the roughness element on the location of laminar-turbulent transition inside the boundary layer, the instability characteristics of the stationary wake behind the roughness element are investigated over a range of roughness heights. The wake flow adjacent to the spanwise plane of symmetry is characterized by a narrow region of increased boundary layer thickness. Beyond the near wake region, the centerline streak is surrounded by a pair of high-speed streaks with reduced boundary layer thickness and a secondary, outer pair of lower-speed streaks. Similar to the spanwise periodic pattern of streaks behind an array of regularly spaced roughness elements, the above wake structure persists over large distances and can sustain strong enough convective instabilities to cause an earlier onset of transition when the roughness height is sufficiently large. Time accurate computations are performed to clarify additional issues such as the role of the nearfield of the roughness element during the generation of streak instabilities, as well as to reveal selected details of their nonlinear evolution. Effects of roughness element shape on the streak amplitudes and the interactions between multiple roughness elements aligned along the flow direction are also investigated.

Pile construction

DOEpatents

Johnson, Alfred A.; Carleton, John T.

1978-05-02

A graphite-moderated, water-cooled nuclear reactor including graphite blocks disposed in transverse alternate layers, one set of alternate layers consisting of alternate full size blocks and smaller blocks through which cooling tubes containing fuel extend, said smaller blocks consisting alternately of tube bearing blocks and support block, the support blocks being smaller than the tube bearing blocks, the aperture of each support block being tapered so as to provide the tube extending therethrough with a narrow region of support while being elsewhere spaced therefrom.

The Nanocrystalline State of Narrow Gap Semiconducting Chalcogenides

DTIC Science & Technology

2010-08-23

using a 1 nm scanning probe and the EDS microanalysis . For Annealing studies nanocrystal powder samples were placed in ceramic crucibles and annealed...nanocrystals are homogenous single phase EDS spectral images were collected in scanning transmission electron microcopy using a 1 nm electron probe...explorations with alio-valent elements (e.g. Sb3+, Ag+ doping in PbTe). • Perform chemical and physical characterization to demonstrate that nanocrystals are

Warfighting in Cyberspace

DTIC Science & Technology

2007-01-01

warfare ). Although the defensive elements of IO and cyber warfare are important, to narrow the scope of our thesis, the remainder of the argu- ment...adversary decisions away from taking action against our will. Now, let us contrast IO doctrine with what we propose for cyber warfare . The focus of... cyber warfare is on using cyberspace (by operating within or through it) to attack personnel, facilities, or equipment with the intent of degrading

Development of Multidisciplinary, Multifidelity Analysis, Integration, and Optimization of Aerospace Vehicles

DTIC Science & Technology

2010-02-27

investigated in more detail. The intermediate level of fidelity, though more expensive, is then used to refine the analysis , add geometric detail, and...design stage is used to further refine the analysis , narrowing the design to a handful of options. Figure 1. Integrated Hierarchical Framework. In...computational structural and computational fluid modeling. For the structural analysis tool we used McIntosh Structural Dynamics’ finite element code CNEVAL

Selenium, zinc, copper, Cu/Zn ratio and total antioxidant status in the serum of vitiligo patients treated by narrow-band ultraviolet-B phototherapy.

PubMed

Wacewicz, Marta; Socha, Katarzyna; Soroczyńska, Jolanta; Niczyporuk, Marek; Aleksiejczuk, Piotr; Ostrowska, Jolanta; Borawska, Maria H

2018-03-01

Vitiligo is a chronic, depigmenting skin disorder, whose pathogenesis is still unknown. Narrow band ultraviolet-B (NB-UVB) is now one of the most widely used treatment of vitiligo. It was suggested that trace elements may play a role in pathogenesis of vitiligo. The aim of this study was to estimate the concentration of selenium (Se), zinc (Zn), copper (Cu) and Cu/Zn ratio as well as total antioxidant status (TAS) in the serum of patients with vitiligo. We assessed 50 patients with vitiligo and 58 healthy controls. Serum levels of Se, Zn and Cu were determined by the atomic absorption spectrometry method, and the Cu/Zn ratio was also calculated. TAS in serum was measured spectrophotometrically. Serum concentration of Se in patients with vitiligo before and after phototherapy was significantly lower as compared to the control group. Zn level in the serum of patients decreased significantly after phototherapy. We observed higher Cu/Zn ratio (p < .05) in examined patients than in the control group and after NB-UVB. We have found decrease in TAS in the serum of vitiligo patients after NB-UVB. The current study showed some disturbances in the serum levels of trace elements and total antioxidant status in vitiligo patients.

Multifrequency Ultra-High Resolution Miniature Scanning Microscope Using Microchannel And Solid-State Sensor Technologies And Method For Scanning Samples

NASA Technical Reports Server (NTRS)

Wang, Yu (Inventor)

2006-01-01

A miniature, ultra-high resolution, and color scanning microscope using microchannel and solid-state technology that does not require focus adjustment. One embodiment includes a source of collimated radiant energy for illuminating a sample, a plurality of narrow angle filters comprising a microchannel structure to permit the passage of only unscattered radiant energy through the microchannels with some portion of the radiant energy entering the microchannels from the sample, a solid-state sensor array attached to the microchannel structure, the microchannels being aligned with an element of the solid-state sensor array, that portion of the radiant energy entering the microchannels parallel to the microchannel walls travels to the sensor element generating an electrical signal from which an image is reconstructed by an external device, and a moving element for movement of the microchannel structure relative to the sample. Discloses a method for scanning samples whereby the sensor array elements trace parallel paths that are arbitrarily close to the parallel paths traced by other elements of the array.

Coherently coupled high-power fiber arrays

NASA Astrophysics Data System (ADS)

Anderegg, Jesse; Brosnan, Stephen; Cheung, Eric; Epp, Paul; Hammons, Dennis; Komine, Hiroshi; Weber, Mark; Wickham, Michael

2006-02-01

A four-element fiber array has demonstrated 470 watts of coherently phased, linearly polarized light energy in a single far-field spot. Each element consists of a single-mode fiber-amplifier chain. Phase control of each element is achieved with a Lithium-Niobate phase modulator. A master laser provides a linearly polarized, narrow linewidth signal that is split into five channels. Four channels are individually amplified using polarization maintaining fiber power amplifiers. The fifth channel is used as a reference arm. It is frequency shifted and then combined interferometrically with a portion of each channel's signal. Detectors sense the heterodyne modulation signal, and an electronics circuit measures the relative phase for each channel. Compensating adjustments are then made to each channel's phase modulator. This effort represents the results of a multi-year effort to achieve high power from a single element fiber amplifier and to understand the important issues involved in coherently combining many individual elements to obtain sufficient optical power for directed energy weapons. Northrop Grumman Corporation and the High Energy Laser Joint Technology Office jointly sponsored this work.

High-Energy Anomaly in the Angle-Resolved Photoemission Spectra of Nd2-xCexCuO4: Evidence for a Matrix Element Effect

NASA Astrophysics Data System (ADS)

Rienks, E. D. L.; ńrrälä, M.; Lindroos, M.; Roth, F.; Tabis, W.; Yu, G.; Greven, M.; Fink, J.

2014-09-01

We use polarization-dependent angle-resolved photoemission spectroscopy (ARPES) to study the high-energy anomaly (HEA) in the dispersion of Nd2-xCexCuO4, x =0.123. We find that at particular photon energies the anomalous, waterfall-like dispersion gives way to a broad, continuous band. This suggests that the HEA is a matrix element effect: it arises due to a suppression of the intensity of the broadened quasiparticle band in a narrow momentum range. We confirm this interpretation experimentally, by showing that the HEA appears when the matrix element is suppressed deliberately by changing the light polarization. Calculations of the matrix element using atomic wave functions and simulation of the ARPES intensity with one-step model calculations provide further evidence for this scenario. The possibility to detect the full quasiparticle dispersion further allows us to extract the high-energy self-energy function near the center and at the edge of the Brillouin zone.

High-energy anomaly in the angle-resolved photoemission spectra of Nd(2-x)Ce(x)CuO₄: evidence for a matrix element effect.

PubMed

Rienks, E D L; Ärrälä, M; Lindroos, M; Roth, F; Tabis, W; Yu, G; Greven, M; Fink, J

2014-09-26

We use polarization-dependent angle-resolved photoemission spectroscopy (ARPES) to study the high-energy anomaly (HEA) in the dispersion of Nd(2-x)Ce(x)CuO₄, x=0.123. We find that at particular photon energies the anomalous, waterfall-like dispersion gives way to a broad, continuous band. This suggests that the HEA is a matrix element effect: it arises due to a suppression of the intensity of the broadened quasiparticle band in a narrow momentum range. We confirm this interpretation experimentally, by showing that the HEA appears when the matrix element is suppressed deliberately by changing the light polarization. Calculations of the matrix element using atomic wave functions and simulation of the ARPES intensity with one-step model calculations provide further evidence for this scenario. The possibility to detect the full quasiparticle dispersion further allows us to extract the high-energy self-energy function near the center and at the edge of the Brillouin zone.

Situational awareness within objective structured clinical examination stations in undergraduate medical training - a literature search.

PubMed

Fischer, Markus A; Kennedy, Kieran M; Durning, Steven; Schijven, Marlies P; Ker, Jean; O'Connor, Paul; Doherty, Eva; Kropmans, Thomas J B

2017-12-21

Medical students may not be able to identify the essential elements of situational awareness (SA) necessary for clinical reasoning. Recent studies suggest that students have little insight into cognitive processing and SA in clinical scenarios. Objective Structured Clinical Examinations (OSCEs) could be used to assess certain elements of situational awareness. The purpose of this paper is to review the literature with a view to identifying whether levels of SA based on Endsley's model can be assessed utilising OSCEs during undergraduate medical training. A systematic search was performed pertaining to SA and OSCEs, to identify studies published between January 1975 (first paper describing an OSCE) and February 2017, in peer reviewed international journals published in English. PUBMED, EMBASE, PsycINFO Ovid and SCOPUS were searched for papers that described the assessment of SA using OSCEs among undergraduate medical students. Key search terms included "objective structured clinical examination", "objective structured clinical assessment" or "OSCE" and "non-technical skills", "sense-making", "clinical reasoning", "perception", "comprehension", "projection", "situation awareness", "situational awareness" and "situation assessment". Boolean operators (AND, OR) were used as conjunctions to narrow the search strategy, resulting in the limitation of papers relevant to the research interest. Areas of interest were elements of SA that can be assessed by these examinations. The initial search of the literature retrieved 1127 publications. Upon removal of duplicates and papers relating to nursing, paramedical disciplines, pharmacy and veterinary education by title, abstract or full text, 11 articles were eligible for inclusion as related to the assessment of elements of SA in undergraduate medical students. Review of the literature suggests that whole-task OSCEs enable the evaluation of SA associated with clinical reasoning skills. If they address the levels of SA, these OSCEs can provide supportive feedback and strengthen educational measures associated with higher diagnostic accuracy and reasoning abilities. Based on the findings, the early exposure of medical students to SA is recommended, utilising OSCEs to evaluate and facilitate SA in dynamic environments.

OWL representation of the geologic timescale implementing stratigraphic best practice

NASA Astrophysics Data System (ADS)

Cox, S. J.

2011-12-01

The geologic timescale is a cornerstone of the earth sciences. Versions are available from many sources, with the following being of particular interest: (i) The official International Stratigraphic Chart (ISC) is maintained by the International Commission for Stratigraphy (ICS), following principles developed over the last 40 years. ICS provides the data underlying the chart as part of a specialized software package, and the chart itself as a PDF using the standard colours; (ii) ITC Enschede has developed a representation of the timescale as a thesaurus in SKOS, used in a Web Map Service delivery system; (iii) JPL's SWEET ontology includes a geologic timescale. This takes full advantage of the capabilities of OWL. However, each of these has limitations - The ISC falls down because of incompatibility with web technologies; - While SKOS supports multilingual labelling, SKOS does not adequately support timescale semantics, in particular since it does not include ordering relationships; - The SWEET version (as of version 2) is not fully aligned to the model used by ICS, in particular not recognizing the role of the Global Boundary Stratotype Sections and Point (GSSP). Furthermore, it is distributed as static documents, rather than through a dynamic API using SPARQL. The representation presented in this paper overcomes all of these limitations as follows: - the timescale model is formulated as an OWL ontology - the ontology is directly derived from the UML representation of the ICS best practice proposed by Cox & Richard [2005], and subsequently included as the Geologic Timescale package in GeoSciML (http://www.geosciml.org); this includes links to GSSPs as per the ICS process - key properties in the ontology are also asserted to be subProperties of SKOS properties (topConcept and broader/narrower relations) in order to support SKOS-based queries; SKOS labelling is used to support multi-lingual naming and synonyms - the International Stratigraphic Chart is implemented as a set of instances of classes from the ontology, and published through a SPARQL end-point - the elements of the Stratigraphic chart are linked to the corresponding elements in SWEET (Raskin et al., 2011) and DBpedia to support traceability between different commonly accessed representations. The ontology builds on standard geospatial information models, including the Observations and Measurements model (ISO 19156), and GeoSciML. This allows the ages given in the chart to be linked to the evidence basis found in the associated GeoSciML features.

Cascaded chirped narrow bandpass filter with flat-top based on two-dimensional photonic crystals.

PubMed

Zhuang, Yuyang; Chen, Heming; Ji, Ke

2017-05-10

We propose a structure of a cascaded chirped narrow bandpass filter with a flat-top based on two-dimensional (2D) photonic crystals (PhCs). The filter discussed here consists of three filter units, each with a resonator and two reflectors. Coupled mode theory and transfer matrix method are methodologies applied in the analysis of the features. The calculations show that the bandwidth of the filter can be adjusted by changing the distances between resonators and reflectors, and based on this, a flat-top response can be achieved by chirped-cascading the filter units. According to the theoretical model, we design a narrow bandpass filter based on 2D PhCs with a triangular lattice of air holes, the parameters of which are calculated using the finite element method. The simulation results show that the filter has a center frequency of 193.40 THz, an insertion loss of 0.18 dB, a flat bandwidth of 40 GHz, and ripples of about 0.2 dB in the passband. The filter is suitable for dense-wavelength-division-multiplexed optical communication systems with 100 GHz channel spacing.

Dynamics of a population of oscillatory and excitable elements.

PubMed

O'Keeffe, Kevin P; Strogatz, Steven H

2016-06-01

We analyze a variant of a model proposed by Kuramoto, Shinomoto, and Sakaguchi for a large population of coupled oscillatory and excitable elements. Using the Ott-Antonsen ansatz, we reduce the behavior of the population to a two-dimensional dynamical system with three parameters. We present the stability diagram and calculate several of its bifurcation curves analytically, for both excitatory and inhibitory coupling. Our main result is that when the coupling function is broad, the system can display bistability between steady states of constant high and low activity, whereas when the coupling function is narrow and inhibitory, one of the states in the bistable regime can show persistent pulsations in activity.

Measuring Elemental Abundances in Impulsive Heating Events with EIS

NASA Astrophysics Data System (ADS)

Warren, Harry; Doschek, George A.; Young, Peter

2015-04-01

It is well established that elemental abundances vary in the solar atmosphere and that this variation is organized by first ionization potential (FIP). Previous studies have indicated that in the solar corona low FIP elements, such as Fe, Si, and Mg, are enriched relative to high FIP elements, such as H, He, C, N, and O. In this paper we report on measurements of plasma composition made during transient heating events observed at transition region temperatures with the Extreme Ultraviolet Imaging Spectrometer (EIS) on Hinode. During these events the intensities of O IV, V, and VI emission lines are enhanced relative to emission lines from Mg V, VI, and VII and indicate a composition close to that of the photosphere. Differential emission measure calculations show a broad distribution of temperatures in these events. Long-lived coronal structures, in contrast, show an enrichment of low FIP elements and relatively narrow temperature distributions. We conjecture that plasma composition is an important signature of the coronal heating process, with impulsive heating leading to the evaporation of unfractionated material from the lower layers of the solar atmosphere and higher frequency heating leading to the accumulation of low-FIP elements in the corona.

Narrow-Front Loop Migration in a Population of the Common Cuckoo Cuculus canorus, as Revealed by Satellite Telemetry

PubMed Central

Willemoes, Mikkel; Strandberg, Roine; Klaassen, Raymond H. G.; Tøttrup, Anders P.; Vardanis, Yannis; Howey, Paul W.; Thorup, Kasper; Wikelski, Martin; Alerstam, Thomas

2014-01-01

Narrow migration corridors known in diurnal, social migrants such as raptors, storks and geese are thought to be caused by topographical leading line effects in combination with learning detailed routes across generations. Here, we document narrow-front migration in a nocturnal, solitary migrant, the common cuckoo Cuculus canorus, using satellite telemetry. We tracked the migration of adult cuckoos from the breeding grounds in southern Scandinavia (n = 8), to wintering sites in south-western Central Africa (n = 6) and back to the breeding grounds (n = 3). Migration patterns were very complex; in addition to the breeding and wintering sites, six different stopover sites were identified during the 16,000 km annual route that formed a large-scale clockwise loop. Despite this complexity, individuals showed surprisingly similar migration patterns, with very little variation between routes. We compared observed tracks with simulated routes based on vector orientation (with and without effects of barriers on orientation and survival). Observed distances between routes were often significantly smaller than expected if the routes were established on the basis of an innate vector orientation programme. Average distance between individuals in eastern Sahel after having migrated more than 5,000 km for example, was merely 164 km. This implies that more sophisticated inherent guiding mechanisms, possibly involving elements of intermediate goal area navigation or more elaborate external cues, are necessary to explain the complex narrow-front migration pattern observed for the cuckoos in this study. PMID:24421890

Single-mode surface plasmon distributed feedback lasers.

PubMed

Karami Keshmarzi, Elham; Tait, R Niall; Berini, Pierre

2018-03-29

Single-mode surface plasmon distributed feedback (DFB) lasers are realized in the near infrared using a two-dimensional non-uniform long-range surface plasmon polariton structure. The surface plasmon mode is excited onto a 20 nm-thick, 1 μm-wide metal stripe (Ag or Au) on a silica substrate, where the stripe is stepped in width periodically, forming a 1st order Bragg grating. Optical gain is provided by optically pumping a 450 nm-thick IR-140 doped PMMA layer as the top cladding, which covers the entire length of the Bragg grating, thus creating a DFB laser. Single-mode lasing peaks of very narrow linewidth were observed for Ag and Au DFBs near 882 nm at room temperature. The narrow linewidths are explained by the low spontaneous emission rate into the surface plasmon lasing mode as well as the high quality factor of the DFB structure. The lasing emission is exclusively TM polarized. Kinks in light-light curves accompanied by spectrum narrowing were observed, from which threshold pump power densities can be clearly identified (0.78 MW cm-2 and 1.04 MW cm-2 for Ag and Au DFB lasers, respectively). The Schawlow-Townes linewidth for our Ag and Au DFB lasers is estimated and very narrow linewidths are predicted for the lasers. The lasers are suitable as inexpensive, recyclable and highly coherent sources of surface plasmons, or for integration with other surface plasmon elements of similar structure.

Stability and Marginal Bone Level Changes of SLActive Titanium-Zirconium Implants Placed with Flapless Surgery: A Prospective Pilot Study.

PubMed

Altinci, Pinar; Can, Gulsen; Gunes, Onur; Ozturk, Caner; Eren, Hakan

2016-12-01

Immediately-loaded, narrow-diameter implants can be a less invasive alternative for the implant-supported fixed rehabilitation of narrow, posterior crests. To determine the stability and marginal bone level (MBL) changes of narrow-diameter, titanium-zirconium (TiZr) implants placed with flapless surgery and loaded immediately in the posterior region. Thirty-eight TiZr implants (3.3 mm diameter, 10 mm length, Roxolid, Straumann AG) were placed in the posterior crests of 14 patients with computer-guided flapless surgery as a support of 3-unit posterior bridges. Eighteen implants were loaded immediately, and 20 implants were loaded conventionally. The implant stability quotients were determined at the 1, 2, 4, and 8. weeks of healing before conventional loading, and at the 3, 6, and 12. months after loading by resonance frequency analysis. The MBL changes were measured by digital radiography. The surgical protocols were accomplished without any biological complications. There was no significant difference in the stability changes of TiZr implants between the loading groups (p > .05). The MBL changes were -0.18 ± 0.27 mm and -0.24 ± 0.27 mm at the 12. month of immediate and conventional loading, respectively, which was not statistically significant (p > .05). The stability and MBL changes of TiZr implants supporting posterior 3-unit bridges were clinically acceptable at the first year of loading. © 2016 Wiley Periodicals, Inc.

Determinant factors of industrial symbiosis: greening Pasir Gudang industrial park

NASA Astrophysics Data System (ADS)

Teh, B. T.; Ho, C. S.; Matsuoka, Y.; Chau, L. W.; Gomi, K.

2014-02-01

Green industry has been identified as an important element in attaining greater sustainability. It calls for harmonizing robust economic growth with environment protection. Industries, particularly in developing and transitional nations such as Malaysia, are in need of a reform. Many experts and international organizations suggest the concept of industrial symbiosis. Mainly, there are successful cases of industrial symbiosis practices around the world. However, there are numerous cases of failure too. As industrial symbiosis is an emerging new approach, with a short history of two decades, a lot of researches are generally focused on narrow context and technical details. There is a lack of concerted efforts to look into the drivers and barriers of industrial symbiosis across different cases. This paper aims to examine the factors influencing the development of industrial symbiosis from various countries to supports such networks to evolve in Pasir Gudang. The findings show institution, law and regulation, finance, awareness and capacity building, technology, research and development, information, collaboration, market, geography proximity, environmental issues and industry structure affect the formation of industrial symbiosis.

Size, Shape and Impurity Effects on Superconducting critical temperature.

NASA Astrophysics Data System (ADS)

Umeda, Masaki; Kato, Masaru; Sato, Osamu

Bulk superconductors have their own critical temperatures Tc. However, for a nano-structured superconductor, Tc depends on size and shape of the superconductor. Nishizaki showed that the high pressure torsion on bulks of Nb makes Tc higher, because the torsion makes many nano-sized fine grains in the bulks. However the high pressure torsion on bulks of V makes Tc lower, and Nishizaki discussed that the decrease of Tc is caused by impurities in the bulks of V. We studied size, shape, and impurity effects on Tc, by solving the Gor'kov equations, using the finite element method. We found that smaller and narrower superconductors show higher Tc. We found how size and shape affects Tc by studying spacial order parameter distributions and quasi-particle eigen-energies. Also we studied the impurity effects on Tc, and found that Tc decreases with increase of scattering rate by impurities. This work was supported in part of KAKENHI Grant Number JP26400367 and JP16K05460, and program for leading graduate schools of ministry of education, culture, sports, science and technology-Japan.

Performance of an on-chip superconducting circulator for quantum microwave systems

NASA Astrophysics Data System (ADS)

Chapman, Benjamin; Rosenthal, Eric; Moores, Bradley; Kerckhoff, Joseph; Mates, J. A. B.; Hilton, G. C.; Vale, L. R.; Ullom, J. N.; LalumíEre, Kevin; Blais, Alexandre; Lehnert, K. W.

Microwave circulators enforce a single propagation direction for signals in an electrical network. Unfortunately, commercial circulators are bulky, lossy, and cannot be integrated close to superconducting circuits because they require strong ( kOe) magnetic fields produced by permanent magnets. Here we report on the performance of an on-chip, active circulator for superconducting microwave circuits, which uses no permanent magnets. Non-reciprocity is achieved by actively modulating reactive elements around 100 MHz, giving roughly a factor of 50 in the separation between signal and control frequencies, which facilitates filtering. The circulator's active components are dynamically tunable inductors constructed with arrays of dc-SQUIDs in series. Array inductance is tuned by varying the magnetic flux through the SQUIDs with fields weaker than 1 Oe. Although the instantaneous bandwidth of the device is narrow, the operation frequency is tunable between 4 and 8 GHz. This presentation will describe the device's theory of operation and compare its measured performance to design goals. This work is supported by the ARO under contract W911NF-14-1-0079 and the National Science Foundation under Grant Number 1125844.

Polarization-dependent thin-film wire-grid reflectarray for terahertz waves

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

Niu, Tiaoming; School of Information Science and Engineering, Lanzhou University, Lanzhou 730000; Upadhyay, Aditi

2015-07-20

A thin-film polarization-dependent reflectarray based on patterned metallic wire grids is realized at 1 THz. Unlike conventional reflectarrays with resonant elements and a solid metal ground, parallel narrow metal strips with uniform spacing are employed in this design to construct both the radiation elements and the ground plane. For each radiation element, a certain number of thin strips with an identical length are grouped to effectively form a patch resonator with equivalent performance. The ground plane is made of continuous metallic strips, similar to conventional wire-grid polarizers. The structure can deflect incident waves with the polarization parallel to the stripsmore » into a designed direction and transmit the orthogonal polarization component. Measured radiation patterns show reasonable deflection efficiency and high polarization discrimination. Utilizing this flexible device approach, similar reflectarray designs can be realized for conformal mounting onto surfaces of cylindrical or spherical devices for terahertz imaging and communications.« less

Excited Ejecta in Light of Sight from Eta Car

NASA Technical Reports Server (NTRS)

Vieira, G.; Gull, T. R.; Danks, A.

2003-01-01

In the NUV spectrum of Eta Car, we have resolved many narrow absorption lines of neutral and singly-ionized elements with the Space Telescope Imaging Spectrograph. We report for the first time the detection of interstellar vanadium in absorption, and many highly-excited absorption lines of Fe, Cr, Ti, Ni, Co, Mn, and Mg. These elements, normally tied up in dust grains in the ISM, are located within wall of the Homunculus within 20,000 A.U. of Eta Car. Stellar radiation and stellar wind are interacting with the wall. Dust is likely being modified and/or destroyed. Previous Homunculus studies have demonstrated that nitrogen is overabundant and that carbon and oxygen emission lines are weak, or non-existent. Are the large column densities of these heavy elements due to abundance effects, excitation mechanisms, or modified grains? We may gain insight as Eta Car goes through its spectroscopic minimum in the summer of 2003.

Dynamics of reflection high-energy electron diffraction intensity oscillations during molecular beam epitaxial growth of GaAs on (111)B GaAs substrates

NASA Astrophysics Data System (ADS)

Yen, M. Y.; Haas, T. W.

1990-06-01

We have observed intensity oscillations in reflection high-energy electron diffraction during molecular beam epitaxial growth of GaAs on (111)B GaAs substrates. These oscillations only exist over a narrow range of growth conditions and their behavior is strongly dependent on the migration kinetics of group III and the molecular dissociative reaction of group V elements.

Finite Ground Coplanar (FGC) Waveguide: It's Characteristics and Advantages for Use in RF and Wireless Communication Circuits

NASA Technical Reports Server (NTRS)

Ponchak, George E.; Katehi, Linda P. B.; Tentzeris, Emmanouil M.

1998-01-01

To solve many of the problems encountered when using conventional coplanar waveguide (CPW) with its semi-infinite ground planes, a new version of coplanar waveguide with electrically narrow ground planes has been developed. This new transmission line which we call Finite Ground Coplanar (FGC) waveguide has several advantages which make it a better transmission line for RF and wireless circuits. Since the ground planes are electrically narrow, spurious resonances created by the CPW ground planes and the metal carrier or package base are eliminated. In addition, lumped and distributed circuit elements may now be integrated into the ground strips in the same way as they traditionally have been integrated into the center conductor to realize novel circuit layouts that are smaller and have less parasitic reactance. Lastly, FGC is shown to have lower coupling between adjacent transmission lines than conventional CPW.

Linewidth dependence of coherent terahertz emission from Bi2Sr2CaCu2O8 intrinsic Josephson junction stacks in the hot-spot regime

NASA Astrophysics Data System (ADS)

Li, Mengyue; Yuan, Jie; Kinev, Nickolay; Li, Jun; Gross, Boris; Guénon, Stefan; Ishii, Akira; Hirata, Kazuto; Hatano, Takeshi; Koelle, Dieter; Kleiner, Reinhold; Koshelets, Valery P.; Wang, Huabing; Wu, Peiheng

2012-08-01

We report on measurements of the linewidth Δf of terahertz radiation emitted from intrinsic Josephson junction stacks, using a Nb/AlN/NbN integrated receiver for detection. Previous resolution-limited measurements indicated that Δf may be below 1 GHz—much smaller than expected from a purely cavity-induced synchronization. While at low bias we found Δf to be not smaller than ˜500 MHz, at high bias, where a hot spot coexists with regions which are still superconducting, Δf turned out to be as narrow as 23 MHz. We attribute this to the hot spot acting as a synchronizing element. Δf decreases with increasing bath temperature, a behavior reminiscent of motional narrowing in NMR or electron spin resonance (ESR), but hard to explain in standard electrodynamic models of Josephson junctions.

Narrow sidebranch arrays for low frequency duct noise control.

PubMed

Tang, S K

2012-11-01

The present study investigates the sound transmission loss across a section of an infinitely long duct where one or more narrow sidebranch tubes are installed flushed with the duct wall. The finite-element method is used to compute the wave propagation characteristics, and a simplified theoretical analysis is carried out at the same time to explain the wave mechanism at frequencies of high sound reduction. Results show that the high sound transmission loss at a particular frequency is due to the concerted actions of three consecutive sidebranch tubes with the most upstream one in the resonant state. The expansion chamber effect of the setup also plays a role in enhancing sound attenuation at non-resonance frequencies. Broadband performance of the device can be greatly enhanced by appropriate arrangements of tube lengths and/or by coupling arrays on the two sides of the duct.

Microstrip patch antenna receiving array operating in the Ku band

NASA Technical Reports Server (NTRS)

Walcher, Douglas A.

1996-01-01

Microstrip patch antennas were first investigated from the idea that it would be highly advantageous to fabricate radiating elements (antennas) on the same dielectric substrate as RF circuitry and transmission lines. Other advantages were soon discovered to be its lightweight, low profile, conformability to shaped surfaces, and low manufacturing costs. Unfortunately, these same patches continually exhibit narrow bandwidths, wide beamwidths, and low antenna gain. This thesis will present the design and experimental results of a microstrip patch antenna receiving array operating in the Ku band. An antenna array will be designed in an attempt to improve its performance over a single patch. Most Ku band information signals are either wide band television images or narrow band data and voice channels. An attempt to improve the gain of the array by introducing parasitic patches on top of the array will also be presented in this thesis.

Lubricated immersed boundary method in two dimensions

NASA Astrophysics Data System (ADS)

Fai, Thomas G.; Rycroft, Chris H.

2018-03-01

Many biological examples of fluid-structure interaction, including the transit of red blood cells through the narrow slits in the spleen and the intracellular trafficking of vesicles into dendritic spines, involve the near-contact of elastic structures separated by thin layers of fluid. Motivated by such problems, we introduce an immersed boundary method that uses elements of lubrication theory to resolve thin fluid layers between immersed boundaries. We demonstrate 2nd-order accurate convergence for simple two-dimensional flows with known exact solutions to showcase the increased accuracy of this method compared to the standard immersed boundary method. Motivated by the phenomenon of wall-induced migration, we apply the lubricated immersed boundary method to simulate an elastic vesicle near a wall in shear flow. We also simulate the dynamics of a vesicle traveling through a narrow channel and observe the ability of the lubricated method to capture the vesicle motion on relatively coarse fluid grids.

Narrow-field imaging of the lunar sodium exosphere

NASA Technical Reports Server (NTRS)

Stern, S. Alan; Flynn, Brian C.

1995-01-01

We present the first results of a new technique for imaging the lunar Na atmosphere. The technique employs high resolution, a narrow bandpass, and specific observing geometry to suppress scattered light and image lunar atmospheric Na I emission down to approximately 50 km altitude. Analysis of four latitudinally dispersed images shows that the lunar Na atmosphere exhibits intersting latitudinal and radial dependencies. Application of a simple Maxwellian collisionless exosphere model indicates that: (1) at least two thermal populations are required to adequately fit the soldium's radial intensity behavior, and (2) the fractional abundances and temperatures of the two components vary systematically with latitude. We conclude that both cold (barometric) and hot (suprathermal) Na may coexist in the lunar atmosphere, either as distinct components or as elements of a continuum of populations ranging in temperature from the local surface temperature up to or exceeding escape energies.

Method for fabricating a microscale anemometer

NASA Technical Reports Server (NTRS)

Liu, Chang (Inventor); Chen, Jack (Inventor)

2008-01-01

Method for fabricating a microscale anemometer on a substrate. A sacrificial layer is formed on the substrate, and a metal thin film is patterned to form a sensing element. At least one support for the sensing element is patterned. The sacrificial layer is removed, and the sensing element is lifted away from the substrate by raising the supports, thus creating a clearance between the sensing element and the substrate to allow fluid flow between the sensing element and the substrate. The supports are raised preferably by use of a magnetic field applied to magnetic material patterned on the supports.

Physicochemically functional ultrathin films by interfacial polymerization

DOEpatents

Lonsdale, Harold K.; Babcock, Walter C.; Friensen, Dwayne T.; Smith, Kelly L.; Johnson, Bruce M.; Wamser, Carl C.

1990-01-01

Interfacially-polymerized ultrathin films containing physicochemically functional groups are disclosed, both with and without supports. Various applications are disclsoed, including membrane electrodes, selective membranes and sorbents, biocompatible materials, targeted drug delivery, and narrow band optical absorbers.

The method for scanning reshaping the spectrum of chirped laser pulse based on the quadratic electro-optic effects

NASA Astrophysics Data System (ADS)

Ye, Rong; Yin, Ming; Wu, Xianyun; Tan, Hang

2017-10-01

T A new method for scanning reshaping the spectrum of chirped laser pulse based on quadratic electro-optic effects is proposed. The scanning reshaping scheme with a two-beam interference system is designed and the spectrum reshaping properties are analyzed theoretically. For the Gaussian chirped laser pulse with central wavelength λ0=800nm, nearly flat-topped spectral profiles with wider bandwidth is obtained with the proposed scanning reshaping method, which is beneficial to compensate for the gain narrowing effect in CPA and OPCPA. Further numerical simulations show that the reshaped spectrum is sensitive to the time-delay and deviation of the voltage applied to the crystal. In order to avoid narrowing or distorting the reshaped spectrum pointing to target, it is necessary to reduce the unfavorable deviations. With the rapid and wide applications of ultra-short laser pulse supported by some latter research results including photo-associative formation of ultra-cold molecules from ultra-cold atoms[1-3], laser-induced communications[4], capsule implosions on the National Ignition Facility(NIF)[5-6], the control of the temporal and spectral profiles of laser pulse is very important and urgently need to be addressed. Generally, the control of the pulse profiles depends on practical applications, ranging from femtosecond and picosecond to nanosecond. For instance, the basic shaping setup is a Fourier transform system for ultra-short laser pulse. The most important element is a spatially patterned mask which modulates the phase or amplitude, or sometimes the polarization after the pulse is decomposed into its constituent spectral components by usually a grating and a lens[7]. One of the generation techniques of ultra-short laser pulse is the chirped pulse amplifications(CPA), which brings a new era of development for high energy and high peak intensity ultra-short laser pulse, proposed by D. Strcik and G. Mourou from the chirping radar technology in microwave region since 1985[8]. The other generation technique of ultra-short pulse is the optical parametric chirped pulse amplification(OPCPA) invented by Dubietis et al. in 1992, which combined the respective superiorities of CPA and optical parametric amplification(OPA). However, there are disadvantages for the both technologies such as gain narrowing, gain saturation effects, and even spectrum shift. The first one among the three is the most significant which narrows the spectrum after amplification so that it limits the minimum durations of ultra-short laser pulse. This paper proposed a approach for scanning reshaping the spectrum of chirped laser pulse to compensate for the gain narrowing effect, according to the characteristics of the chirped laser pulse, i.e. the frequency varies with time linearly. The spectral characteristics of the scanning reshaping was analyzed quantitatively. Furthermore, the influence of the time-delay and deviation of the controlling voltage employed on the electro-optic crystal on the reshaped spectrum was also been discussed in detail.

Single-Layer, All-Metal Patch Antenna Element with Wide Bandwidth

NASA Technical Reports Server (NTRS)

Chamberlain, Neil F.; Hodges, Richard E.; Zawardzki, Mark S.

2012-01-01

It is known that the impedance at the center of a patch antenna element is a short circuit, implying that a wire or post can be connected from the patch to the groundplane at this point without impacting radiation performance. In principle, this central post can be used to support the patch element, thus eliminating the need for dielectric. In spaceborne applications, this approach is problematic because a patch element supported by a single, thin post is highly susceptible to acoustic loads during launch. The technology reported here uses a large-diameter center post as its supporting structure. The supporting structure allows for the fabrication of a sufficiently rigid antenna element that can survive launch loads. The post may be either hollow or solid, depending on fabrication approach and/or mass constraints. The patch antenna element and support post are envisioned as being fabricated (milled) from a single piece of aluminum or other metal. Alternately, the patch plate and support column can be fabricated separately and then joined using fasteners, adhesive, or welding. Casting and electroforming are also viable techniques for manufacturing the metal patch part(s). The patch structure is then either bonded or fastened to the supporting groundplane. Arrays of patch elements can be fabricated by attaching several structures to a common groundplane/support structure.

Support for the beam focusing hypothesis in the false killer whale.

PubMed

Kloepper, Laura N; Buck, John R; Smith, Adam B; Supin, Alexander Ya; Gaudette, Jason E; Nachtigall, Paul E

2015-08-01

The odontocete sound production system is complex and composed of tissues, air sacs and a fatty melon. Previous studies suggested that the emitted sonar beam might be actively focused, narrowing depending on target distance. In this study, we further tested this beam focusing hypothesis in a false killer whale. Using three linear arrays of hydrophones, we recorded the same emitted click at 2, 4 and 7 m distance and calculated the beamwidth, intensity, center frequency and bandwidth as recorded on each array at every distance. If the whale did not focus her beam, acoustics predicts the intensity would decay with range as a function of spherical spreading and the angular beamwidth would remain constant. On the contrary, our results show that as the distance from the whale to the array increases, the beamwidth is narrower and the received click intensity is higher than that predicted by a spherical spreading function. Each of these measurements is consistent with the animal focusing her beam on a target at a given range. These results support the hypothesis that the false killer whale is 'focusing' its sonar beam, producing a narrower and more intense signal than that predicted by spherical spreading. © 2015. Published by The Company of Biologists Ltd.

No evidence for [O III] variability in Mrk 142

NASA Astrophysics Data System (ADS)

Barth, Aaron J.; Bentz, Misty C.

2016-05-01

Using archival data from the 2008 Lick AGN Monitoring Project, Zhang & Feng claimed to find evidence for flux variations in the narrow [O III] emission of the Seyfert 1 galaxy Mrk 142 over a two-month time span. If correct, this would imply a surprisingly compact size for the narrow-line region. We show that the claimed [O III] variations are merely the result of random errors in the overall flux calibration of the spectra. The data do not provide any support for the hypothesis that the [O III] flux was variable during the 2008 monitoring period.

Enabling Narrow(est) IWA Coronagraphy with STIS BAR5 and BAR10 Occulters

NASA Astrophysics Data System (ADS)

Schneider, Glenn; Gaspar, Andras; Debes, John; Gull, Theodore; Hines, Dean; Apai, Daniel; Rieke, George

2017-09-01

The Space Telescope Imaging Spectrograph's (STIS) BAR5 coronagraphic occulter was designed to provide high-contrast, visible-light, imaging in close (> 0.15") angular proximity to bright point-sources. We explored and verified the functionality and utility of the BAR5 occulter. We also investigated, and herein report on, the use of the BAR10 rounded corners as narrow-angle occulters and compare IWA vs. contrast performance for the BAR5, BAR10, and Wedge occulters. With that, we provide recommendations for the most efficacious BAR5 and BAR10 use on-orbit in support of GO science.

Biomechanics of Tetrahymena escaping from dead ends

NASA Astrophysics Data System (ADS)

Ishikawa, Takuji; Kikuchi, Kenji

2017-11-01

Behaviors of swimming microorganisms in complex environments are important in understanding cells' distribution in nature and in industries. Although cell's swimming and spreading in an infinite fluid has been intensively investigated, that in a narrow region bounded by walls is still unclear. Thus, in this study, we used Tetrahymena thermophila as a model microorganism, and experimentally investigated its behavior between flat plates with an angle. The results showed that the cells tended to escape from the narrow region, and the swimming velocity and the radius of curvature of the trajectories decreased as they swam narrower region. We then developed a computational model of swimming Tetrahymena. The results showed that the escaping behavior could be well explained by fluid mechanics. The obtained knowledge is useful in understanding cells' behaviors in complex environments, such as in porous media and in a granular matter. This research was supported by JSPS KAKENHI Grants, numbers 25000008 and 17H00853.

Large bandgap narrowing in rutile TiO2 aimed towards visible light applications and its correlation with vacancy-type defects history and transformation

NASA Astrophysics Data System (ADS)

Nair, Radhika V.; Gayathri, P. K.; Siva Gummaluri, Venkata; Nambissan, P. M. G.; Vijayan, C.

2018-01-01

Extension of photoactivity of TiO2 to the visible region is achievable via effective control over the intrinsic defects such as oxygen and Ti vacancies, which has several applications in visible photocatalysis and sensing. We present here the first observation of an apparent bandgap narrowing and bandgap tuning effect due to vacancy cluster transformation in rutile TiO2 structures to 1.84 eV from the bulk bandgap of 3 eV. A gradual transformation of divacancies (V Ti-O) to tri vacancies ({{V}Ti-O-T{{i-}}} ) achieved through a controlled solvothermal scheme appears to result in an apparent narrowing bandgap and tunability, as supported by positron annihilation lifetime and electron paramagnetic resonance spectroscopy measurements. Visible photocatalytic activity of the samples is demonstrated in terms of photodegradation of rhodamine B dye molecules.

Activin receptor inhibition by Smad2 regulates Drosophila wing disc patterning through BMP-response elements

PubMed Central

Peterson, Aidan J.; O'Connor, Michael B.

2013-01-01

Imaginal disc development in Drosophila requires coordinated cellular proliferation and tissue patterning. In our studies of TGFβ superfamily signaling components, we found that a protein null mutation of Smad2, the only Activin subfamily R-Smad in the fruit fly, produces overgrown wing discs that resemble gain of function for BMP subfamily signaling. The wing discs are expanded specifically along the anterior-posterior axis, with increased proliferation in lateral regions. The morphological defect is not observed in mutants for the TGFβ receptor baboon, and epistasis tests showed that baboon is epistatic to Smad2 for disc overgrowth. Rescue experiments indicate that Baboon binding, but not canonical transcription factor activity, of Smad2 is required for normal disc growth. Smad2 mutant discs generate a P-Mad stripe that is narrower and sharper than the normal gradient, and activation targets are correspondingly expressed in narrowed domains. Repression targets of P-Mad are profoundly mis-regulated, with brinker and pentagone reporter expression eliminated in Smad2 mutants. Loss of expression requires a silencer element previously shown to be controlled by BMP signaling. Epistasis experiments show that Baboon, Mad and Schnurri are required to mediate the ectopic silencer output in the absence of Smad2. Taken together, our results show that loss of Smad2 permits promiscuous Baboon activity, which represses genes subject to control by Mad-dependent silencer elements. The absence of Brinker and Pentagone in Smad2 mutants explains the compound wing disc phenotype. Our results highlight the physiological relevance of substrate inhibition of a kinase, and reveal a novel interplay between the Activin and BMP pathways. PMID:23293296

The effect of pre-evaporation on ion distributions in inductively coupled plasma mass spectrometry

NASA Astrophysics Data System (ADS)

Liu, Shulan; Beauchemin, Diane

2006-02-01

The connecting tube (2 or 5-mm i. d., 11-cm long) between the spray chamber and the torch was heated (to 400 °C) to investigate the effect of pre-evaporation on the distribution of ions in inductively coupled plasma mass spectrometry (ICP-MS). Axial and radial profiles of analyte ions (Al +, V +, Cr +, Ni +, Zn +, Mn +, Zn +, As +, Se +, Mo +, Cd +, Sb +, La +, Pb +) in 1% HNO 3 as well as some polyatomic ions (LaO +, ArO +, ArN +, CO 2+) were simultaneously obtained on a time-of-flight ICP-MS instrument. Upon heating the connecting tube, the optimal axial position of all elements shifted closer to the load coil. Without the heated tube, 3.5 mm was the compromise axial position for multielemental analysis, which was optimal for 6 analytes. With the heated tube, this position became 1.5 mm, which was then optimal for 9 of the 14 analytes. Furthermore, the radial profiles, which were wide with a plateau in their middle without heating, became significantly narrower and Gaussian-like with a heated tube. This narrowing, which was most important for the 5-mm tube, slightly (by a factor of two at the most) yet significantly (at the 95% confidence level) improved the sensitivity of all elements but Mn upon optimisation of the axial position for compromise multi-element analysis. Furthermore, a concurrent decrease in the standard deviation of the blank was significant at the 95% confidence level for 9 of the 14 analytes. For most of the analytes, this translated into a two-fold to up to an order of magnitude improvement in detection limit, which is commensurate with a reduction of noise resulting from the smaller droplets entering the plasma after traversing the pre-evaporation tube.

Photoeffect cross sections of several rare-earth elements for 323-keV photons

NASA Astrophysics Data System (ADS)

Umesh, T. K.; Anasuya, S. J.; Shylaja Kumari, J.; Gowda, Channe; Gopinathan Nair, K. P.; Gowda, Ramakrishna

1992-02-01

Total-attenuation cross sections of the oxides of rare-earth elements such as La, Ce, Pr, Nd, Sm, Gd, Dy, Ho, and Er, and also NaNO3 and NaNO2 have been measured in a narrow-beam geometry setup at 323 keV. The total-attenuation cross section for oxygen was obtained as the difference in NaNO3 and NaNO2 cross sections. Using this, the total-attenuation cross sections of the individual lanthanides have been obtained with the aid of the mixture rule. From these, the photoeffect cross sections were derived by subtracting the scattering contribution. These values are found to agree well with Scofield's theoretical data [University of California Report No. UCRL 51326, 1973 (unpublished)].

Physicochemically functional ultrathin films by interfacial polymerization

DOEpatents

Lonsdale, H.K.; Babcock, W.C.; Friensen, D.T.; Smith, K.L.; Johnson, B.M.; Wamser, C.C.

1990-08-14

Interfacially-polymerized ultrathin films containing physicochemically functional groups are disclosed, both with and without supports. Various applications are disclosed, including membrane electrodes, selective membranes and sorbents, biocompatible materials, targeted drug delivery, and narrow band optical absorbers. 3 figs.

The stability of cassette walls in compression

NASA Astrophysics Data System (ADS)

Voutay, Pierre-Arnaud

Much research into the behaviour of cold formed steel columns in the last decade has focused on channel sections undergoing local, distortional and overall buckling. Light gauge steel cassette sections are a particular form of channel section which offers an alternative form of load-bearing wall assembly for use in low-rise steel framed construction. Cassette wall sections possess wide and slender flanges so that, by including intermediate stiffeners in these wide flanges, a significant increase in the ultimate load capacity may be achieved. However, the introduction of intermediate stiffeners also increases the number of buckling modes (stiffener buckling) and, therefore complicates the behaviour and increases the risk of interactive buckling between these modes. The work undertaken in this thesis aims to clarify the behaviour of wide flanges in compression with and without intermediate stiffeners. In this research, the distortional mode of web and narrow flange buckling was inhibited by connecting the narrow flanges of the cassettes together at suitable intervals. "Generalised Beam Theory" (GBT), which allows the individual buckling modes to be considered individually and in predetermined combinations, provides a particularly good tool with which to analyse and understand the buckling behaviour of cassette sections with and without intermediate stiffeners. "Generalised Beam Theory" (GBT) is used throughout this work to determine the elastic buckling stress of the sections studied (simply supported stiffened plates, as well as cassette sections). Since the economic design of cold-formed steel sections requires the consideration of post- buckling behaviour, elastic buckling values are not directly comparable with design code values which are usually based on the concept of effective width. Therefore, finite element analysis with both material and geometric nonlinearity has also been carried out in order to obtain the ultimate strength in the critical mode or mode combination. Firstly the results of experimental test are analysed and their behaviour reproduced numerically. This serves to explain the test results and verify the numerical model. Confidence in modelling non-linear instability phenomena with the finite element method is acquired. Secondly, an initial parametric study was undertaken on the behaviour of cassette sections with and without intermediate stiffeners. This study considers the effect of the length and overall buckling on the behaviour of cassette sections, the effect of load eccentricity and the effect of the rotational restraint given by the web to the stiffened wide flange. A second parametric study including 96 specimens was undertaken next. This study considered the effect of the number (up to three intermediate stiffeners) and sizes of intermediate stiffeners on slender flanges with a slenderness ratio between 150 ≤ w/t ≤ 600. A wide range of geometries was studied covering single and interactive buckling modes. Comparison of the ultimate strength obtained from finite element analysis with the ultimate strength obtained using the effective width approach of modem design codes such as Eurocode 3 part 1.3 (1996) and NAS (North American specification (2001)) was then possible. By integrating the stress distribution over the length of the specimen, the stiffened wide flange can be isolated from the rest of the section (webs and narrow flanges). Design procedures tor plate elements incorporating one or two intermediate stiffeners under compressive load are given in Eurocode 3; Part 1.3. However, cassette sections, which have wider and more slender flanges than typical sheeting and decking, are increasingly being used in practical construction. For such cases, the design procedures in Eurocode 3 are less well founded. An improvement of the Eurocode 3 procedure dealing with intermediate stiffeners is proposed and validated for one, two or three stiffeners. Throughout the work, simple expressions suitable for design calculations are presented. Modern design codes as well as Direct Strength Method are evaluated in the light of findings of this work and wherever possible suggestions for improvements are made.

Effects of narrow-base walking and dual tasking on gait spatiotemporal characteristics in anterior cruciate ligament-injured adults compared to healthy adults.

PubMed

Mazaheri, Masood; Negahban, Hossein; Soltani, Maryam; Mehravar, Mohammad; Tajali, Shirin; Hessam, Masumeh; Salavati, Mahyar; Kingma, Idsart

2017-08-01

The present experiment was conducted to examine the hypothesis that challenging control through narrow-base walking and/or dual tasking affects ACL-injured adults more than healthy control adults. Twenty male ACL-injured adults and twenty healthy male adults walked on a treadmill at a comfortable speed under two base-of-support conditions, normal-base versus narrow-base, with and without a cognitive task. Gait patterns were assessed using mean and variability of step length and mean and variability of step velocity. Cognitive performance was assessed using the number of correct counts in a backward counting task. Narrow-base walking resulted in a larger decrease in step length and a more pronounced increase in variability of step length and of step velocity in ACL-injured adults than in healthy adults. For most of the gait parameters and for backward counting performance, the dual-tasking effect was similar between the two groups. ACL-injured adults adopt a more conservative and more unstable gait pattern during narrow-base walking. This can be largely explained by deficits of postural control in ACL-injured adults, which impairs gait under more balance-demanding conditions. The observation that the dual-tasking effect did not differ between the groups may be explained by the fact that walking is an automatic process that involves minimal use of attentional resources, even after ACL injury. Clinicians should consider the need to include aspects of terrain complexity, such as walking on a narrow walkway, in gait assessment and training of patients with ACL injury. III.

Elements of a Workplace Culture of Health, Perceived Organizational Support for Health, and Lifestyle Risk.

PubMed

Payne, Julianne; Cluff, Laurie; Lang, Jason; Matson-Koffman, Dyann; Morgan-Lopez, Antonio

2018-01-01

We investigated the impact of elements of a workplace culture of health (COH) on employees' perceptions of employer support for health and lifestyle risk. We used 2013 and 2015 survey data from the National Healthy Worksite Program, a Centers for Disease Control and Prevention (CDC)-led initiative to help workplaces implement health-promoting interventions. Forty-one employers completed the CDC Worksite Health Scorecard to document organizational changes. Eight hundred twenty-five employees provided data to evaluate changes in their health and attitudes. We defined elements of a COH as environmental, policy, and programmatic supports; leadership and coworker support; employee engagement (motivational interventions); and strategic communication. Outcomes included scores of employees' perceptions of employer support for health and lifestyle risk derived from self-reported physical activity, nutrition, and tobacco use. We estimated effects using multilevel regression models. At the employee level and across time, regression coefficients show positive associations between leadership support, coworker support, employee engagement, and perceived support for health ( P < .05). Coefficients suggest a marginally significant negative association between lifestyle risk and the presence of environmental and policy supports ( P < .10) and significant associations with leadership support in 2015 only ( P < .05). Relational elements of COH (leadership and coworker support) tend to be associated with perceived support for health, while workplace elements (environmental and policy supports) are more associated with lifestyle risk. Employers need to confront relational and workplace elements together to build a COH.

Charge line quad pulser

DOEpatents

Booth, R.

1996-10-08

A quartet of parallel coupled planar triodes is removably mounted in a quadrahedron shaped PCB structure. Releasable brackets and flexible means attached to each triode socket make triode cathode and grid contact with respective conductive coatings on the PCB and a detachable cylindrical conductive element enclosing and contacting the triode anodes jointly permit quick and easy replacement of faulty triodes. By such orientation, the quad pulser can convert a relatively low and broad pulse into a very high and narrow pulse. 16 figs.

Charge line quad pulser

DOEpatents

Booth, Rex

1996-01-01

A quartet of parallel coupled planar triodes is removably mounted in a quadrahedron shaped PCB structure. Releasable brackets and flexible means attached to each triode socket make triode cathode and grid contact with respective conductive coatings on the PCB and a detachable cylindrical conductive element enclosing and contacting the triode anodes jointly permit quick and easy replacement of faulty triodes. By such orientation, the quad pulser can convert a relatively low and broad pulse into a very high and narrow pulse.

Electrochemical photovoltaic cell having ternary alloy film

DOEpatents

Russak, Michael A.

1984-01-01

A thin film compound semiconductor electrode comprising CdSe.sub.1-x Te.sub.x (0.ltoreq.x.ltoreq.1) is deposited on a transparent conductive substrate. An electrolyte contacts the film to form a photoactive site. The semiconductor material has a narrow energy bandgap permitting high efficiency for light conversion. The film may be fabricated by: (1) co-evaporation of two II-VI group compounds with a common cation, or (2) evaporation of three elements, concurrenty.

Large magnetoresistance in non-magnetic silver chalcogenides and new class of magnetoresistive compounds

DOEpatents

Saboungi, Marie-Louis; Price, David C. L.; Rosenbaum, Thomas F.; Xu, Rong; Husmann, Anke

2001-01-01

The heavily-doped silver chalcogenides, Ag.sub.2+.delta. Se and Ag.sub.2+.delta. Te, show magnetoresistance effects on a scale comparable to the "colossal" magnetoresistance (CMR) compounds. Hall coefficient, magnetoconductivity, and hydrostatic pressure experiments establish that elements of narrow-gap semiconductor physics apply, but both the size of the effects at room temperature and the linear field dependence down to fields of a few Oersteds are surprising new features.

Airborne water vapor DIAL system and measurements of water and aerosol profiles

NASA Technical Reports Server (NTRS)

Higdon, Noah S.; Browell, Edward V.

1991-01-01

The Lidar Applications Group at NASA Langley Research Center has developed a differential absorption lidar (DIAL) system for the remote measurement of atmospheric water vapor (H2O) and aerosols from an aircraft. The airborne H2O DIAL system is designed for extended flights to perform mesoscale investigations of H2O and aerosol distributions. This DIAL system utilizes a Nd:YAG-laser-pumped dye laser as the off-line transmitter and a narrowband, tunable Alexandrite laser as the on-line transmitter. The dye laser has an oscillator/amplifier configuration which incorporates a grating and prism in the oscillator cavity to narrow the output linewidth to approximately 15 pm. This linewidth can be maintained over the wavelength range of 725 to 730 nm, and it is sufficiently narrow to satisfy the off-line spectral requirements. In the Alexandrite laser, three intracavity tuning elements combine to produce an output linewidth of 1.1 pm. These spectral devices include a five-plate birefringent tuner, a 1-mm thick solid etalon and a 1-cm air-spaced etalon. A wavelength stability of +/- 0.35 pm is achieved by active feedback control of the two Fabry-Perot etalons using a frequency stabilized He-Ne laser as a wavelength reference. The three tuning elements can be synchronously scanned over a 150 pm range with microprocessor-based scanning electronics. Other aspects of the DIAL system are discussed.

Does the stoichiometric carbon:phosphorus knife edge apply for predaceous copepods?

PubMed

Laspoumaderes, Cecilia; Modenutti, Beatriz; Elser, James J; Balseiro, Esteban

2015-06-01

Recent work has indicated that stoichiometric food quality in terms of the carbon:phosphorus (C:P) ratio affects consumers whether the imbalance involves a deficit or an excess of nutrients; hence, organisms exist on a "stoichiometric knife edge". While previous studies have focused primarily on autotroph-herbivore trophic transfer, nutritional imbalances may also affect the interactions between species at higher trophic levels. Since the foods of carnivores are normally stoichiometrically similar to the body compositions of those carnivores, they may be more severely affected than herbivores if imbalances become pronounced. We analysed the response of the predatory copepod Parabroteas sarsi to monospecific diet treatments consisting of high and low C:P prey items. These dietary treatments strongly affected the predator's elemental composition and growth, although prey selection, excretion, egestion, and respiration rates were not affected. We suggest that, due to their low threshold elemental ratio and a narrow C:P stoichiometric knife edge, these predators are highly vulnerable to stoichiometric imbalances, whether an excess or a deficit of nutrients is involved. Our results demonstrating this high sensitivity to prey C:P ratio show that the stoichiometric knife edge may apply to not only herbivores but also higher trophic levels. Thus, predators such as P. sarsi, with a much narrower range of food quality, may also be strongly affected by fluctuations in the quality of their prey, with negative consequences for their secondary production.

Spectral element method for elastic and acoustic waves in frequency domain

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

Shi, Linlin; Zhou, Yuanguo; Wang, Jia-Min

Numerical techniques in time domain are widespread in seismic and acoustic modeling. In some applications, however, frequency-domain techniques can be advantageous over the time-domain approach when narrow band results are desired, especially if multiple sources can be handled more conveniently in the frequency domain. Moreover, the medium attenuation effects can be more accurately and conveniently modeled in the frequency domain. In this paper, we present a spectral-element method (SEM) in frequency domain to simulate elastic and acoustic waves in anisotropic, heterogeneous, and lossy media. The SEM is based upon the finite-element framework and has exponential convergence because of the usemore » of GLL basis functions. The anisotropic perfectly matched layer is employed to truncate the boundary for unbounded problems. Compared with the conventional finite-element method, the number of unknowns in the SEM is significantly reduced, and higher order accuracy is obtained due to its spectral accuracy. To account for the acoustic-solid interaction, the domain decomposition method (DDM) based upon the discontinuous Galerkin spectral-element method is proposed. Numerical experiments show the proposed method can be an efficient alternative for accurate calculation of elastic and acoustic waves in frequency domain.« less

Precision Measurements with a Molecular Clock

NASA Astrophysics Data System (ADS)

Grier, Andrew; McDonald, Mickey; McGuyer, Bart; Iwata, Geoffrey; Apfelbeck, Florian; Tarallo, Marco; Zelevinsky, Tanya

2015-05-01

We report on recent results obtained with photoassociated Sr2 molecules confined in a lattice. Sr2 has a range of electronically excited bound states which are readily accessible with optical wavelengths using the narrow 1S0->3P1 intercombination line. As in Nat. Phys. 11, 32, we measure the lifetimes of the narrow, deeply-bound subradiant states in the 1g (1S0+3P1 dissociative limit) potential, allowing for coherent control of molecules and a comparison with theoretical predictions of the lifetimes and transition strengths of these states. Next, we study ultracold photodissociation of Sr2 molecules through abortion of one and two photons near the atomic intercombination line. This allows us to observe the vector character of transition elements through the angular dissociation pattern and to directly measure barrier heights in the excited state potentials. Finally, as shown in PRL 114, 023001, we demonstrate that in a non-magic lattice, a narrow transition can be used to measure the trapped gas temperature through the linewidth of the spectral feature corresponding to the carrier transitions. We use this technique to measure the temperature of Sr2 molecules to 10x higher precision than with standard techniques. We discuss future prospects with this molecular lattice clock. Funding from NIST, ARO, and NSF IGERT.

Inter-band optoelectronic properties in quantum dot structure of low band gap III-V semiconductors

NASA Astrophysics Data System (ADS)

Dey, Anup; Maiti, Biswajit; Chanda Sarkar, Debasree

2014-04-01

A generalized theory is developed to study inter-band optical absorption coefficient (IOAC) and material gain (MG) in quantum dot structures of narrow gap III-V compound semiconductor considering the wave-vector (k→) dependence of the optical transition matrix element. The band structures of these low band gap semiconducting materials with sufficiently separated split-off valance band are frequently described by the three energy band model of Kane. This has been adopted for analysis of the IOAC and MG taking InAs, InSb, Hg1-xCdxTe, and In1-xGaxAsyP1-y lattice matched to InP, as example of III-V compound semiconductors, having varied split-off energy band compared to their bulk band gap energy. It has been found that magnitude of the IOAC for quantum dots increases with increasing incident photon energy and the lines of absorption are more closely spaced in the three band model of Kane than those with parabolic energy band approximations reflecting the direct the influence of energy band parameters. The results show a significant deviation to the MG spectrum of narrow-gap materials having band nonparabolicity compared to the parabolic band model approximations. The results reflect the important role of valence band split-off energies in these narrow gap semiconductors.

Fano resonances of a ring-shaped "hexamer" cluster at near-infrared wavelength

NASA Astrophysics Data System (ADS)

Liu, Tong-Tong; Xia, Feng; Sun, Peng; Liu, Li-Li; Du, Wei; Li, Meng-Xue; Kong, Wei-Jin; Wan, Yong; Dong, Li-Feng; Yun, Mao-Jin

2018-03-01

Fano resonances have been studied intensely in the last decade, since it is an important way to decrease the resonance line width and enhance local electric field. However, achieving a Fano line-shape with both narrow line width and high spectral contrast ratio is still a challenge. In this paper, we theoretically predict the Fano resonance induced by the extinction of normal plane wave in a ring-shaped hexamer cluster at near-infrared wavelength. In order to obtain the narrow Fano line width and high spectral contrast ratio, the relationships between the Fano line-shape and the parameters of the nanostructure are analyzed in detail. The nanostructure is simulated by using commercial software based on finite element method. The simulation results show that when the structural parameters are optimized, the Fano line width can be narrowed down 0.028 eV with a contrast ratio of 86%, and the local electric field enhancement factor at the Fano resonance wavelength can reach to 36. Furthermore, the effective mode volume of the structure is 3.9 ×10-23m3 which is lower than the available literature. These results indicate many potential applications of the Fano resonance in multiwavelength surface-enhanced Raman scattering and biosensing.

Finite Element-Based Mechanical Assessment of Bone Quality on the Basis of In Vivo Images.

PubMed

Pahr, Dieter H; Zysset, Philippe K

2016-12-01

Beyond bone mineral density (BMD), bone quality designates the mechanical integrity of bone tissue. In vivo images based on X-ray attenuation, such as CT reconstructions, provide size, shape, and local BMD distribution and may be exploited as input for finite element analysis (FEA) to assess bone fragility. Further key input parameters of FEA are the material properties of bone tissue. This review discusses the main determinants of bone mechanical properties and emphasizes the added value, as well as the important assumptions underlying finite element analysis. Bone tissue is a sophisticated, multiscale composite material that undergoes remodeling but exhibits a rather narrow band of tissue mineralization. Mechanically, bone tissue behaves elastically under physiologic loads and yields by cracking beyond critical strain levels. Through adequate cell-orchestrated modeling, trabecular bone tunes its mechanical properties by volume fraction and fabric. With proper calibration, these mechanical properties may be incorporated in quantitative CT-based finite element analysis that has been validated extensively with ex vivo experiments and has been applied increasingly in clinical trials to assess treatment efficacy against osteoporosis.

Discovery deep space optical communications (DSOC) transceiver

NASA Astrophysics Data System (ADS)

Roberts, W. Thomas

2017-02-01

NASA's 22 cm diameter Deep Space Optical Communications (DSOC) Transceiver is designed to provide a bidirectional optical link between a spacecraft in the inner solar system and an Earth-based optical ground station. This design, optimized for operation across a wide range of illumination conditions, is focused on minimizing blinding from stray light, and providing reliable, accurate attitude information to point its narrow communication beam accurately to the future location of the ground terminal. Though our transceiver will transmit in the 1550 nm waveband and receive in the 1064 nm waveband, the system design relies heavily on reflective optical elements, extending flexibility to be modified for use at different wavebands. The design makes use of common path propagation among transmit, receive and pointing verification optical channels to maintain precise alignment among its components, and to naturally correct for element misalignment resulting from launch or thermal element perturbations. This paper presents the results of trade studies showing the evolution of the design, unique operational characteristics of the design, elements that help to maintain minimal stray light contamination, and preliminary results from development and initial testing of a functional aluminum test model.

Social Cognitive Factors, Support, and Engagement: Early Adolescents' Math Interests as Precursors to Choice of Career

ERIC Educational Resources Information Center

Rowan-Kenyon, Heather T.; Swan, Amy K.; Creager, Marie F.

2012-01-01

The authors examined the central hypothesis that students' early perceptions of support and sense of engagement in math classes and math activities strongly influence the broadening or narrowing of their math interest. The focus was on the first wave of qualitative data collected from 5th-, 7th-, and 9th-grade students during the 2007-2008…

Into the Weeds: A Critical Analysis of Game Mechanics and Learning Goals in Games for Learning

ERIC Educational Resources Information Center

Horstman, Theresa

2013-01-01

In the broadest scope, the purpose of this research is to expose the range and complexity of how educational games support learning. In a more narrowed scope, the purpose is to develop a method to help identify the qualities of educational video games that support learning. This is accomplished by analyzing the design of the game and the…

Space-Based Space Surveillance Logistics Case Study: A Qualitative Product Support Element Analysis

DTIC Science & Technology

2017-12-01

Facilities and Infrastructure. Product Support Management and Design Interface are also covered, but only in a general manner. Conclusions from the study...core analysis, with the overarching two elements ( Design Interface and Product Support Management) mentioned briefly. G. THESIS STATEMENT This...were implemented. The two overarching elements of Product Support Management and Design Interface will be discussed briefly in the findings section

Repetitive thinking about the mother during distress moderates the link between children's attentional breadth around the mother and depressive symptoms in middle childhood.

PubMed

Van de Walle, Magali; Bijttebier, Patricia; De Raedt, Rudi; Bosmans, Guy

2017-03-01

It has been suggested that an increased attentional focus on the mother should be maladaptive in middle childhood. However, the effect of a more narrow attentional field around the mother may depend on the mother-child relationship. The current study tested whether a more narrow attentional field around the mother is mainly maladaptive for children who tend to think repetitively about their mother (RTm) during distress. More specifically, it investigates whether RTm during distress provides the context in which an increased attentional focus on the mother is linked to depressive symptoms in middle childhood. RTm was measured using a self-report questionnaire. The breadth of children's attentional field around the mother was measured with the Attentional Breadth Task. This computer task assesses the extent to which children have a more narrow attentional field around the mother compared to unfamiliar women. Results of the current study (N = 157) support the hypothesis that 9-12 year old children who have a more narrow attentional field around the mother and who at the same time report more RTm during distress, have more depressive symptoms. Copyright © 2016 Elsevier Ltd. All rights reserved.

High-Pressure Study of Perovskite-Like Organometal Halide: Band-Gap Narrowing and Structural Evolution of [NH 3 -(CH 2 ) 4 -NH 3 ]CuCl 4

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

Li, Qian; Li, Shourui; Wang, Kai

Searching for nontoxic and stable perovskite-like alternatives to lead-based halide perovskites for photovoltaic application is one urgent issue in photoelectricity science. Such exploration inevitably requires an effective method to accurately control both the crystalline and electronic structures. This work applies high pressure to narrow the band gap of perovskite-like organometal halide, [NH 3-(CH 2) 4-NH 3]CuCl 4 (DABCuCl4), through the crystalline-structure tuning. The band gap keeps decreasing below ~12 GPa, involving the shrinkage and distortion of CuCl 4 2–. Inorganic distortion determines both band-gap narrowing and phase transition between 6.4 and 10.5 GPa, and organic chains function as the springmore » cushion, evidenced by the structural transition at ~0.8 GPa. The supporting function of organic chains protects DABCuCl 4 from phase transition and amorphization, which also contributes to the sustaining band-gap narrowing. This work combines crystal structure and macroscopic property together and offers new strategies for the further design and synthesis of hybrid perovskite-like alternatives.« less

Ergonomically neutral arm support system

DOEpatents

Siminovitch, Michael J; Chung, Jeffrey Y; Dellinges, Steven; Lafever, Robin E

2005-08-02

An ergonomic arm support system maintains a neutral position for the forearm. A mechanical support structure attached to a chair or other mounting structure supports the arms of a sitting or standing person. The system includes moving elements and tensioning elements to provide a dynamic balancing force against the forearms. The support structure is not fixed or locked in a rigid position, but is an active dynamic system that is maintained in equipoise by the continuous operation of the opposing forces. The support structure includes an armrest connected to a flexible linkage or articulated or pivoting assembly, which includes a tensioning element such as a spring. The pivoting assembly moves up and down, with the tensioning element providing the upward force that balances the downward force of the arm.

A decrease in phytic acid content substantially affects the distribution of mineral elements within rice seeds.

PubMed

Sakai, Hiroaki; Iwai, Toru; Matsubara, Chie; Usui, Yuto; Okamura, Masaki; Yatou, Osamu; Terada, Yasuko; Aoki, Naohiro; Nishida, Sho; Yoshida, Kaoru T

2015-09-01

Phytic acid (myo-inositol hexakisphosphate; InsP6) is the storage compound of phosphorus and many mineral elements in seeds. To determine the role of InsP6 in the accumulation and distribution of mineral elements in seeds, we performed fine mappings of mineral elements through synchrotron-based X-ray microfluorescence analysis using developing seeds from two independent low phytic acid (lpa) mutants of rice (Oryza sativa L.). The reduced InsP6 in lpa seeds did not affect the translocation of mineral elements from vegetative organs into seeds, because the total amounts of phosphorus and the other mineral elements in lpa seeds were identical to those in the wild type (WT). However, the reduced InsP6 caused large changes in mineral localization within lpa seeds. Phosphorus and potassium in the aleurone layer of lpa greatly decreased and diffused into the endosperm. Zinc and copper, which were broadly distributed from the aleurone layer to the inner endosperm in the WT, were localized in the narrower space around the aleurone layer in lpa mutants. We also confirmed that similar distribution changes occurred in transgenic rice with the lpa phenotype. Using these results, we discussed the role of InsP6 in the dynamic accumulation and distribution patterns of mineral elements during seed development. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

A Coast Mountains provenance for the Valdez and Orca groups, southern Alaska, based on Nd, Sr, and Pb isotopic evidence

USGS Publications Warehouse

Farmer, G.L.; Ayuso, R.; Plafker, G.

1993-01-01

Nd, Sr, and Pb isotopic data were obtained for fourteen fine- to coarse-grained samples of accreted flysch of the Late Cretaceous and early Tertiary Valdez and Orca Groups in southern Alaska to determine the flysch provenance. Argillites and greywackes from the Orca Group, as well as compositionally similar but higher metamorphic grade rocks from the Valdez Group, show a restricted range of correlated ??{lunate}Nd ( -0.6 to -3.8) and 87Sr 86Sr (0.7060-0.7080) at the time of sediment deposition ( ??? 50 Ma). Pb isotopic compositions also vary over a narrow range ( 206Pb 204Pb = 19.138-19.395, 207Pb 204Pb = 15.593-15.703, 208Pb 204Pb = 38.677-39.209), and in the Orca Group the samples generally become more radiogenic with decreasing ??{lunate}Nd and increasing 87Sr 86Sr. All samples have similar trace element compositions characterized by moderate light rare earth element enrichments, and low ratios of high field strength elements to large ion lithophile elements. Based on petrographic, geochemical, and isotopic data the sedimentary rocks are interpreted to have been derived largely from a Phanerozoic continental margin arc complex characterized by igneous rocks with ??{lunate}Nd values between 0 and -5. The latter conclusion is supported by the ??{lunate}Nd values of a tonalite clast and a rhyodacite clast in the Orca Group (??{lunate}Nd = -4.9 and -0.9, respectively). However, trondjemitic clasts in the Orca Group have significantly lower ??{lunate}Nd ( ??? -10) and require a derivation of a portion of the flysch from Precambrian crustal sources. The Nd, Sr, and Pb isotopic compositions of both the Valdez and Orca Groups overlap the values determined for intrusive igneous rocks exposed within the northern portion of the Late Cretaceous to early Tertiary Coast Mountains Plutonic Complex in western British Columbia and equivalent rocks in southeastern Alaska. The isotopic data support previous conclusions based on geologic studies which suggest that the flysch was shed from this portion of the batholith, and from overlying continental margin arc-related volcanic rocks, following its rapid uplift in the Late Cretaceous and early Tertiary. The Precambrian crustal material present in the flysch may have been derived from Late Proterozoic or older metasedimentary and metaigneous rocks now exposed along the western margin of the Coast Mountains Plutonic Complex. ?? 1993.

Fire resistant PV shingle assembly

DOEpatents

Lenox, Carl J.

2012-10-02

A fire resistant PV shingle assembly includes a PV assembly, including PV body, a fire shield and a connection member connecting the fire shield below the PV body, and a support and inter-engagement assembly. The support and inter-engagement assembly is mounted to the PV assembly and comprises a vertical support element, supporting the PV assembly above a support surface, an upper interlock element, positioned towards the upper PV edge, and a lower interlock element, positioned towards the lower PV edge. The upper interlock element of one PV shingle assembly is inter-engageable with the lower interlock element of an adjacent PV shingle assembly. In some embodiments the PV shingle assembly may comprise a ventilation path below the PV body. The PV body may be slidably mounted to the connection member to facilitate removal of the PV body.

Electrical Connector for Graphite Heating Elements

NASA Technical Reports Server (NTRS)

Mackintosh, B. H.

1982-01-01

Connection method applies force to two interfaces: that between heating element proper and heating-element support members and between heating-element support members and metal conductor. Inner rod of new connector system is maintained in tension by a spring (for example, Belleville washers). Connection is sufficiently complaint so tension remains within desired range, regardless of thermal expansion and contraction of various elements.

Lasing of a Solid-State Active Element Based on Anodized Aluminum Oxide Film Doped with Rhodamine 6G

NASA Astrophysics Data System (ADS)

Shelkovnikov, V. V.; Lyubas, G. A.; Korotaev, S. V.; Kopylova, T. N.; Tel'minov, E. N.; Gadirov, R. M.; Nikonova, E. N.; Nikonov, S. Yu.; Solodova, T. A.; Novikov, V. A.

2017-04-01

Spectral-luminescent and lasing characteristics of rhodamine 6G in porous aluminum oxide films anodized under various conditions are investigated. Lasing is obtained without external resonator in the longitudinal scheme under excitation by the second harmonic of Nd3+:YAG-laser radiation. The threshold pump power densities are in the range 3.5-15 MW/cm2 depending on the anodizing conditions. Wherein, the lasing line narrows down from 12 to 5 nm.

Effect of Implant Diameter and Ridge Dimension on Stress Distribution in Mandibular First Molar Sites-A Photoelastic Study.

PubMed

Termeie, Deborah; Klokkevold, Perry R; Caputo, Angelo A

2015-10-01

The long-term clinical success of a dental implant is dependent upon maintaining sufficient osseointegration to resist forces of occlusion. The purpose of this study was to investigate the effect of implant diameter on stress distribution around screw-type dental implants in mandibular first molar sites using photoelastic models. The design included models with different buccal-lingual dimension. Twelve composite photoelastic models were assembled using 2 different resins to simulate trabecular and cortical bone. Half of the models were fabricated with average dimensions for ridge width and the other half with narrower buccal-lingual dimensions. One internal connection implant (13 mm length) with either a standard (4 mm), wide (5 mm), or narrow (3.3 mm) diameter was embedded in the first molar position of each photoelastic model. Half the implants were tapered and the other half were straight. Full gold crowns in the shape of a mandibular first molar were fabricated and attached to the implants. Vertical and angled loads of 15 and 30 pounds were applied to specific points on the crown. Wide-diameter implants produced the least stress in all ridges while narrow-diameter implants generated the highest stress, especially in narrow ridges. It may be that the volume and quality of bone surrounding implants influences stress distribution with a greater ratio of cortical to trabecular bone, thus providing better support. Models with wide-diameter implants loaded axially had a more symmetrical stress distribution compared to standard and narrow diameter implants. A more asymmetrical stress pattern developed along the entire implant length with angled loads. Implant diameter and ridge width had considerable influence on stress distribution. Narrow-diameter implants produced more stress than wide diameter implants in all conditions tested.

Laser-excited fluorescence of rare earth elements in fluorite: Initial observations with a laser Raman microprobe

USGS Publications Warehouse

Burruss, R.C.; Ging, T.G.; Eppinger, R.G.; Samson, a.M.

1992-01-01

Fluorescence emission spectra of three samples of fluorite containing 226-867 ppm total rare earth elements (REE) were excited by visible and ultraviolet wavelength lines of an argon ion laser and recorded with a Raman microprobe spectrometer system. Narrow emission lines ( 0.9 for Eu2+ and 0.99 for Er3+. Detection limits for three micrometer spots are about 0.01 ppm Eu2+ and 0.07 ppm Er3+. These limits are less than chondrite abundance for Eu and Er, demonstrating the potential microprobe analytical applications of laser-excited fluorescence of REE in fluorite. However, application of this technique to common rock-forming minerals may be hampered by competition between fluorescence emission and radiationless energy transfer processes involving lattice phonons. ?? 1992.

Optimization of thermoelectric performance of SrSi2-based alloys via the modification in band structure and phonon-point-defect scattering

PubMed Central

Kuo, Yung-Kang; Ramachandran, Balakrishnan; Lue, Chin-Shan

2014-01-01

Thermoelectric properties of alkaline-earth-metal disilicides are strongly dependent on their electronic band structure in the vicinity of the Fermi level. In particular, the strontium disilicide, SrSi2 with a narrow band gap of about few tens of meV is composed of non-toxic, naturally abundant elements, and its thermoelectric properties are very sensitive to the substitution/alloying with third elements. In this article, we summarize the thermoelectric performance of substituted and Sr-deficient/Sr-rich SrSi2 alloys to realize the high thermoelectric figure-of-merit (ZT) for practical applications in the electronic and thermoelectric aspects, and also to explore the alternative routes to further improve its ZT value. PMID:25505784

Adding Some Gas Can Completely Change How an Object in a Liquid-Filled Housing Responds to Vibration

NASA Astrophysics Data System (ADS)

Torczynski, J. R.; O'Hern, T. J.; Clausen, J. R.

2015-11-01

Adding a little gas can completely change the motion of an object in a liquid-filled housing during vibration. A common system exhibiting this behavior is a spring-supported piston in a liquid-filled cylinder, where the gaps between them are narrow and depend on the piston position. When gas is absent, the piston's vibrational response is highly overdamped due to forcing viscous liquid through narrow gaps. When a small amount of gas is added, Bjerknes forces cause some of the gas to migrate below the piston. The resulting two gas regions form a pneumatic spring that enables the liquid to move with the piston, with the result that very little liquid is forced through the narrow gaps. This ``Couette mode'' has low damping and thus has a strong resonance near the frequency given by the pneumatic spring constant and the piston mass. At this frequency, the piston response is large, and the nonlinearity from the gap geometry produces a net force on the piston. This ``rectified'' force can be many times the piston's weight and can cause the piston to compress its supporting spring. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

FINAL REPORT ON GDE GAP CELL

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

Herman, D.; Summers, W.; Danko, E.

2009-09-28

A project has been undertaken to develop an electrochemical cell and support equipment for evaluation of a gas diffusion electrode-based, narrow-electrolyte-gap anode for SO{sub 2} oxidation in the hydrogen production cycle of the hybrid sulfur (HyS) process. The project supported the HyS development program at the Savannah River National Lab (SRNL). The benefits of using a gas diffusion electrode in conjunction with the narrow anolyte gap are being determined through electrochemical polarization testing under a variety conditions, and by comparison to results produced by SRNL and others using anode technologies that have no anolyte gap. These test results indicate thatmore » the NGA cell has low resistance suitable for use in the HyS electrolyzer, exhibits good efficiency at high current densities compared to the direct feed HyS electrolyzer, and indicates robust performance in extended testing over 65 hours. Seepage episodes were mostly caused by port clogging, which can be mitigated in future designs through minor modifications to the hardware. Significant reductions in sulfur crossover have not yet been demonstrated in the NGA configuration compared to in-house direct feed testing, but corroborative sulfur layer analysis is as yet incomplete. Further testing in a single-pass anolyte configuration is recommended for complete evaluation of steady-state electrochemical efficiency and SO{sub 2} crossover in the narrow gap configuration.« less

The (Biological or Cultural) Essence of Essentialism: Implications for Policy Support among Dominant and Subordinated Groups

PubMed Central

Soylu Yalcinkaya, Nur; Estrada-Villalta, Sara; Adams, Glenn

2017-01-01

Most research links (racial) essentialism to negative intergroup outcomes. We propose that this conclusion reflects both a narrow conceptual focus on biological/genetic essence and a narrow research focus from the perspective of racially dominant groups. We distinguished between beliefs in biological and cultural essences, and we investigated the implications of this distinction for support of social justice policies (e.g., affirmative action) among people with dominant (White) and subordinated (e.g., Black, Latino) racial identities in the United States. Whereas, endorsement of biological essentialism may have similarly negative implications for social justice policies across racial categories, we investigated the hypothesis that endorsement of cultural essentialism would have different implications across racial categories. In Studies 1a and 1b, we assessed the properties of a cultural essentialism measure we developed using two samples with different racial/ethnic compositions. In Study 2, we collected data from 170 participants using an online questionnaire to test the implications of essentialist beliefs for policy support. Consistent with previous research, we found that belief in biological essentialism was negatively related to policy support for participants from both dominant and subordinated categories. In contrast, the relationship between cultural essentialism and policy support varied across identity categories in the hypothesized way: negative for participants from the dominant category but positive for participants from subordinated categories. Results suggest that cultural essentialism may provide a way of identification that subordinated communities use to mobilize support for social justice. PMID:28611723

The assessment of source attribution of soil pollution in a typical e-waste recycling town and its surrounding regions using the combined organic and inorganic dataset.

PubMed

Luo, Jie; Qi, Shihua; Xie, Xianming; Gu, X W Sophie; Wang, Jinji

2017-01-01

Guiyu is a well-known electronic waste dismantling and recycling town in south China. Concentrations and distribution of the 21 mineral elements and 16 polycyclic aromatic hydrocarbons (PAHs) collected there were evaluated. Principal component analyses (PCA) applied to the data matrix of PAHs in the soil extracted three major factors explaining 85.7% of the total variability identified as traffic emission, coal combustion, and an unidentified source. By using metallic or metalloid element concentrations as variables, five principal components (PCs) were identified and accounted for 70.4% of the information included in the initial data matrix, which can be denoted as e-waste dismantling-related contamination, two different geological origins, anthropogenic influenced source, and marine aerosols. Combining the 21 metallic and metalloid element datasets with the 16 PAH concentrations can narrow down the coarse source and decrease the unidentified contribution to soil in the present study and therefore effectively assists the source identification process.

How Principals Support Teacher Effectiveness

ERIC Educational Resources Information Center

Gallagher, Michael

2012-01-01

The current standards and accountability regime describes effective teaching as the ability to increase student achievement on standardized tests. This narrow definition of effectiveness can lead principals to create school cultures myopically focused on student achievement data. A "laser-like focus on academic achievement," if employed…

Tools for the Mind

ERIC Educational Resources Information Center

Burns, Mary

2006-01-01

An overly narrow and specialized focus on technology in schools discourages the use of computers to promote higher-order thinking. Many districts have concentrated on skills training, failed to supply such necessary supports as professional development, conflated technology use with instructional quality, and classified all software applications…

Emile's Moral Development. A Rousseauan Perspective on Kohlberg.

ERIC Educational Resources Information Center

Simpson, Evan

1983-01-01

Uses Rousseau's "Emile" to explicate Kohlberg's characterization of moral development and to illuminate several theoretical problems in Kohlberg's cognitive-developmental account. Analysis supports contentions that Kohlberg's concept of morality is unduly narrow and suggests that his one-sidedly rationalistic approach exaggerates the…

Bias Dependence of Radiation-Induced Narrow-Width Channel Effects in 65nm NMOSFETs

NASA Astrophysics Data System (ADS)

Zheng, Qi-Wen; Cui, Jiang-Wei; Wei, Ying; Yu, Xue-Feng; Lu, Wu; Ren, Diyuan; Guo, Qi

2018-04-01

Not Available Supported by the National Natural Science Foundation of China under Grant Nos 11605282, 11505282 and U1532261, and the West Light Foundation of the Chinese Academy of Sciences under Grant No 2015-XBQN-B-15.

FUEL ELEMENT SUPPORT

DOEpatents

Wyman, W.L.

1961-06-27

The described cylindrical fuel element has longitudinally spaced sets of short longitudinal ribs circumferentially spaced from one another. The ribs support the fuel element in a coolant tube so that there is an annular space for coolant flow between the fuel element and the interior of the coolant tube. If the fuel element grows as a result of reactor operation, the circumferential distribution of the ribs maintains the uniformity of the annular space between the coolant tube and the fuel element, and the collapsibility of the ribs prevents the fuel element from becoming jammed in the coolant tube.

The contribution of the polio eradication initiative to narrowing the gaps in the health workforce in the African Region.

PubMed

Kamso, Jean; Mvika, Eddy S; Ota, M O C; Okeibunor, Joseph; Mkanda, Pascal; Mihigo, Richard

2016-10-10

The Global Polio Eradication Initiative (GPEI) massively invested to overcome the crippling disease in countries of the WHO African Region. In the context of economic crisis, almost all countries in the Region lack an adequate health workforce. Large amounts were invested by GPEI in human resources. This paper shows how the human resources funded by polio contributed to narrowing the gaps in health workforce and helped strengthening and supporting other priority health programmes in Angola, Chad, DRC, Nigeria, Tanzania, and Togo. The health workforce strengthening methods used in the five different countries included the following: policy development and strategic planning, microplanning, capacity building of public health and community workers, implementation and services, monitoring and evaluation, advocacy and social mobilization, and programme review. Staff funded by polio helped with achieving good coverage in vitamin A and insecticide-treated mosquito nets (Angola, Chad); improvement of EPI and integrated disease surveillance indicators, improved quality of data (all five countries), administrative support, smooth introduction of new vaccines, increased case detection, and early isolation of patients suffering from the Guinea worm (Chad); reduction of cholera, extension of directly observed TB short course treatment (Democratic Republic of Congo); significant staff performance improvement (Nigeria). GPEI investment achieved far beyond its primary goal, and contributed to narrowing the gaps in the health workforce in countries of the African Region, as demonstrated by the best practice documentation exercise. We recommend that expertise and experience of polio funded staff should be leveraged to strengthen, expand and support other public health programmes. Copyright © 2016 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Dual small fragment plating improves screw-to-screw load sharing for mid-diaphyseal humeral fracture fixation: a finite element study.

PubMed

Kosmopoulos, Victor; Luedke, Colten; Nana, Arvind D

2015-01-01

A smaller humerus in some patients makes the use of a large fragment fixation plate difficult. Dual small fragment plate constructs have been suggested as an alternative. This study compares the biomechanical performance of three single and one dual plate construct for mid-diaphyseal humeral fracture fixation. Five humeral shaft finite element models (1 intact and 4 fixation) were loaded in torsion, compression, posterior-anterior (PA) bending, and lateral-medial (LM) bending. A comminuted fracture was simulated by a 1-cm gap. Fracture fixation was modelled by: (A) 4.5-mm 9-hole large fragment plate (wide), (B) 4.5-mm 9-hole large fragment plate (narrow), (C) 3.5-mm 9-hole small fragment plate, and (D) one 3.5-mm 9-hole small fragment plate and one 3.5-mm 7-hole small fragment plate. Model A showed the best outcomes in torsion and PA bending, whereas Model D outperformed the others in compression and LM bending. Stress concentrations were located near and around the unused screw holes for each of the single plate models and at the neck of the screws just below the plates for all the models studied. Other than in PA bending, Model D showed the best overall screw-to-screw load sharing characteristics. The results support using a dual small fragment locking plate construct as an alternative in cases where crutch weight-bearing (compression) tolerance may be important and where anatomy limits the size of the humerus bone segment available for large fragment plate fixation.

Structure and Function in the Lunge Feeding Apparatus: Mechanical Properties of the Fin Whale Mandible.

PubMed

Shadwick, Robert E; Goldbogen, Jeremy A; Pyenson, Nicholas D; Whale, James C A

2017-11-01

The mandibles of rorqual whales are highly modified to support loads associated with lunge-feeding, a dynamic filter feeding mechanism that is characterized by rapid changes in gape angle and acceleration. Although these structures are the largest ossified elements in animals and an important part of the rorqual engulfment apparatus, details of internal structure are limited and no direct measurements of mechanical properties exist. Likewise, the forces that are sustained by the mandibles are unknown. Here we report on the structure and mechanical behavior of the mandible of an adult fin whale. A series of transverse sections were cut at locations along the entire length of a 3.6-m left mandible recovered post-mortem from a 16-m fin whale, and CT scanned to make density maps. Cored samples 6-8 mm in diameter were tested in compression to determine the Young's modulus and strength. In addition, wet density, dry density and mineral density were measured. Dense cortical bone occupies only a relatively narrow peripheral layer while much less dense and oil-filled trabecular bone occupies the rest. Mineral density of both types is strongly correlated with dry density and CT Hounsfield units. Compressive strength is strongly correlated with Young's modulus, while strength and stiffness are both correlated with mineral density. It appears that the superficial compact layer is the main load bearing element, and that the mandible is reinforced against dorso-vental flexion that would occur during the peak loads while feeding. Anat Rec, 300:1953-1962, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Postacute rehabilitation quality of care: toward a shared conceptual framework.

PubMed

Jesus, Tiago Silva; Hoenig, Helen

2015-05-01

There is substantial interest in mechanisms for measuring, reporting, and improving the quality of health care, including postacute care (PAC) and rehabilitation. Unfortunately, current activities generally are either too narrow or too poorly specified to reflect PAC rehabilitation quality of care. In part, this is caused by a lack of a shared conceptual understanding of what construes quality of care in PAC rehabilitation. This article presents the PAC-rehab quality framework: an evidence-based conceptual framework articulating elements specifically pertaining to PAC rehabilitation quality of care. The widely recognized Donabedian structure, process, and outcomes (SPO) model furnished the underlying structure for the PAC-rehab quality framework, and the International Classification of Functioning, Disability and Health (ICF) framed the functional outcomes. A comprehensive literature review provided the evidence base to specify elements within the SPO model and ICF-derived framework. A set of macrolevel-outcomes (functional performance, quality of life of patient and caregivers, consumers' experience, place of discharge, health care utilization) were defined for PAC rehabilitation and then related to their (1) immediate and intermediate outcomes, (2) underpinning care processes, (3) supportive team functioning and improvement processes, and (4) underlying care structures. The role of environmental factors and centrality of patients in the framework are explicated as well. Finally, we discuss why outcomes may best measure and reflect the quality of PAC rehabilitation. The PAC-rehab quality framework provides a conceptually sound, evidence-based framework appropriate for quality of care activities across the PAC rehabilitation continuum. Copyright © 2015 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Solar System Portrait - Earth as Pale Blue Dot

NASA Image and Video Library

1996-09-12

This narrow-angle color image of the Earth, dubbed Pale Blue Dot, is a part of the first ever 'portrait' of the solar system taken by NASA’s Voyager 1. The spacecraft acquired a total of 60 frames for a mosaic of the solar system from a distance of more than 4 billion miles from Earth and about 32 degrees above the ecliptic. From Voyager's great distance Earth is a mere point of light, less than the size of a picture element even in the narrow-angle camera. Earth was a crescent only 0.12 pixel in size. Coincidentally, Earth lies right in the center of one of the scattered light rays resulting from taking the image so close to the sun. This blown-up image of the Earth was taken through three color filters -- violet, blue and green -- and recombined to produce the color image. The background features in the image are artifacts resulting from the magnification. http://photojournal.jpl.nasa.gov/catalog/PIA00452

Acousto-optic filtering of lidar signals

NASA Technical Reports Server (NTRS)

Kolarov, G.; Deleva, A.; Mitsev, TS.

1992-01-01

The predominant part of the noise in lidar receivers is created by the background radiation; therefore, one of the most important elements of the receiving optics is a spectrally selecting filter placed in front of the photodetector. Interference filters are usually used to transmit a given wavelength. Specific properties of the interference filters, such as simple design, reliability, small size, and large aperture, combined with high transmission coefficient and narrow spectral band, make them the preferred spectral device in many cases. However, problems arise in applications such as the Differential Absorption Lidar (DIAL) technique, where fast tuning within a wide spectral region is necessary. Tunable acousto-optical filters (TAOF), used recently in astrophysical observations to suppress the background radiation, can be employed with success in lidar sounding. They are attractive due to the possibility for fast spectral scanning with a narrow transmission band. The TAOF's advantages are fully evident in DIAL lidars where one must simultaneously receive signals at two laser frequencies.

Mass loss, levitation, accretion, and the sharp-lined features in hot white dwarfs

NASA Technical Reports Server (NTRS)

Bruhweiler, F. C.; Kondo, Y.

1983-01-01

A study has been conducted of eight white dwarfs, including seven DA and one He-rich types. The study is based on high-resolution observations conducted with the aid of the International Ultraviolet Explorer. Four of the dwarfs show features related to heavy elements which are not interstellar in origin. It is tentatively suggested that, at least in the hottest low-gravity DA white dwarfs, the observed narrow-lined features are formed in expanding halos or winds associated with the white dwarfs. Theoretically, stable white dwarf halos should actually be coronae with temperatures in excess of 1,000,000 K. However, the observed narrow-lined features do not suggest such high temperatures. The observed radial velocities suggest weak stellar winds in two hot white dwarfs, namely, G191-B2B and 2111+49. It is tentatively proposed that radiative levitation can explain the appearance of the observed metallic lines in the hot DA white dwarfs.

Noise Radiation From a Leading-Edge Slat

NASA Technical Reports Server (NTRS)

Lockard, David P.; Choudhari, Meelan M.

2009-01-01

This paper extends our previous computations of unsteady flow within the slat cove region of a multi-element high-lift airfoil configuration, which showed that both statistical and structural aspects of the experimentally observed unsteady flow behavior can be captured via 3D simulations over a computational domain of narrow spanwise extent. Although such narrow domain simulation can account for the spanwise decorrelation of the slat cove fluctuations, the resulting database cannot be applied towards acoustic predictions of the slat without invoking additional approximations to synthesize the fluctuation field over the rest of the span. This deficiency is partially alleviated in the present work by increasing the spanwise extent of the computational domain from 37.3% of the slat chord to nearly 226% (i.e., 15% of the model span). The simulation database is used to verify consistency with previous computational results and, then, to develop predictions of the far-field noise radiation in conjunction with a frequency-domain Ffowcs-Williams Hawkings solver.

Performance analysis of higher mode spoof surface plasmon polariton for terahertz sensing

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

Yao, Haizi; Tu, Wanli; Zhong, Shuncong, E-mail: zhongshuncong@hotmail.com

2015-04-07

We investigated the spoof surface plasmon polaritons (SSPPs) on 1D grooved metal surface for terahertz sensing of refractive index of the filling analyte through a prism-coupling attenuated total reflection setup. From the dispersion relation analysis and the finite element method-based simulation, we revealed that the dispersion curve of SSPP got suppressed as the filling refractive index increased, which cause the coupling resonance frequency redshifting in the reflection spectrum. The simulated results for testing various refractive indexes demonstrated that the incident angle of terahertz radiation has a great effect on the performance of sensing. Smaller incident angle will result in amore » higher sensitive sensing with a narrower detection range. In the meanwhile, the higher order mode SSPP-based sensing has a higher sensitivity with a narrower detection range. The maximum sensitivity is 2.57 THz/RIU for the second-order mode sensing at 45° internal incident angle. The proposed SSPP-based method has great potential for high sensitive terahertz sensing.« less

Spectral line narrowing in PPLN OPO devices for 1-μm wavelength doubling

NASA Astrophysics Data System (ADS)

Perrett, Brian J.; Terry, Jonathan A. C.; Mason, Paul D.; Orchard, David A.

2004-12-01

One route to generating mid-infrared (mid-IR) radiation is through a two-stage non-linear conversion process from the near-IR, exploiting powerful neodymium lasers operating at wavelengths close to 1 μm. In the first stage of this process non-linear conversion within a degenerate optical parametric oscillator (OPO) is used to double the wavelength of the 1 μm laser. The resultant 2 μm radiation is then used to pump a second OPO, based on a material such as ZGP, for conversion into the 3 to 5 μm mid-IR waveband. Periodically poled lithium niobate (PPLN) is a useful material for conversion from 1 to 2 μm due to its high non-linear coefficient (deff ~ 16 pm/V) and the long crystal lengths available (up to 50 mm). Slope efficiencies in excess of 40% have readily been achieved using a simple plane-plane resonator when pumped at 10 kHz with 3.5 mJ pulses from a 1.047 μm Nd:YLF laser. However, the OPO output was spectrally broad at degeneracy with a measured full-width-half-maximum (FWHM) linewidth of approximately 65 nm. This output linewidth is significantly broader than the spectral acceptance bandwidth of ZGP for conversion into the mid-IR. In this paper techniques for spectral narrowing the output from a degenerate PPLN OPO are investigated using two passive elements, a diffraction grating and an air spaced etalon. Slope efficiencies approaching 20% have been obtained using the grating in a dog-leg cavity configuration producing spectrally narrow 2 μm output with linewidths as low as 2 nm. A grating-narrowed degenerate PPLN OPO has been successfully used to pump a ZGP OPO.

Intelligent Elements for ISHM

NASA Technical Reports Server (NTRS)

Schmalzel, John L.; Morris, Jon; Turowski, Mark; Figueroa, Fernando; Oostdyk, Rebecca

2008-01-01

There are a number of architecture models for implementing Integrated Systems Health Management (ISHM) capabilities. For example, approaches based on the OSA-CBM and OSA-EAI models, or specific architectures developed in response to local needs. NASA s John C. Stennis Space Center (SSC) has developed one such version of an extensible architecture in support of rocket engine testing that integrates a palette of functions in order to achieve an ISHM capability. Among the functional capabilities that are supported by the framework are: prognostic models, anomaly detection, a data base of supporting health information, root cause analysis, intelligent elements, and integrated awareness. This paper focuses on the role that intelligent elements can play in ISHM architectures. We define an intelligent element as a smart element with sufficient computing capacity to support anomaly detection or other algorithms in support of ISHM functions. A smart element has the capabilities of supporting networked implementations of IEEE 1451.x smart sensor and actuator protocols. The ISHM group at SSC has been actively developing intelligent elements in conjunction with several partners at other Centers, universities, and companies as part of our ISHM approach for better supporting rocket engine testing. We have developed several implementations. Among the key features for these intelligent sensors is support for IEEE 1451.1 and incorporation of a suite of algorithms for determination of sensor health. Regardless of the potential advantages that can be achieved using intelligent sensors, existing large-scale systems are still based on conventional sensors and data acquisition systems. In order to bring the benefits of intelligent sensors to these environments, we have also developed virtual implementations of intelligent sensors.

Coordinating management of water, salinity and trace elements for cotton under mulched drip irrigation with brackish water

NASA Astrophysics Data System (ADS)

Jin, M.; Chen, W.; Liang, X.

2016-12-01

Rational irrigation with brackish water can increase crop production, but irrational use may cause soil salinization. In order to understand the relationships among water, salt, and nutrient (including trace elements) and find rational schemes to manage water, salinity and nutrient in cotton fields, field and pot experiments were conducted in an arid area of southern Xinjiang, northwest China. Field experiments were performed from 2008 to 2015, and involved mulched drip irrigation during the growing season and flood irrigation afterwards. The average cotton yield of seven years varied between 3,575 and 5,095 kg/ha, and the irrigation water productivity between 0.91 and 1.16 kg/m3. With the progress of brackish water irrigation, Cu, Fe, Mn, and Na showed strong aggregation in topsoil at the narrow row, whereas the contents of Ca and K decreased in the order of inter-mulch gap, the wide inter row, and the narrow row. The contents of Cu, Fe, Mn, Ca and K in root soil reduced with cotton growth, whereas Na increased. Although mulched drip irrigation during the growing season resulted in an increase in salinity in the root zone, flood irrigation after harvesting leached the accumulated salts below background levels. Based on experiments a scheme for coordinating management of soil water, salt, and nutrient is proposed, that is, under the planting pattern of one mulch, two drip lines and four rows, the alternative irrigation plus a flood irrigation after harvesting or before seeding was the ideal scheme. Numerical simulations using solute transport model coupled with the root solute uptake based on the experiments and extended by another 20 years, suggest that the mulched drip irrigation using alternatively fresh and brackish water during the growing season and flood irrigation with fresh water after harvesting, is a sustainable irrigation practice that should not lead to soil salinization. Pot experiments with trace elements and different saline water showed significantly antagonistic effects on cotton growth and yield between NaCl and Mn or Zn or B. Zn concentration in irrigation water under salinity stress affected the uptake of nutrient elements and caused the different contents of nutrient elements in cotton, and influenced cotton growth and yields.

Magma Mixing, Mingling and Its Accompanying Isotopic and Elemental Partitioning: Records from Titanites in Guojialing-type Granodiorites and Dioritic Enclaves, Jiaodong, North China

NASA Astrophysics Data System (ADS)

Jiang, P.; Yang, K. F.; Fan, H. R.; Liu, X.

2016-12-01

The grain-scale textural and in-situ compositional analyses on accessory minerals (such as titanite, rutile, apatite, monazite, etc.) have recently been a hot topic for geologists, through which a detailed information on magmatic, metamorphic or hydrothermal process can be extracted. As an attempt to unravel the petrogenesis of Early Cretaceous Guojialing-type granodiorites and their bearing dioritic enclaves, we accomplished an integrated geochronological and geochemical study on titanites within these rocks. Three types of titanites, with distinguishable textural and geochemical features, are identified. G-type titanites (from granodiorites) and E-type-I titanites (from plagioclase-rich dioritic enclaves) yield identical U-Pb age of 130 Ma, but reveal distinct back-scattered electron (BSE) zonings. G-type titanites are characterized by oscillatory zonings whereas E-type-I titanites are marked by core-mantle-rim zonings, exhibiting drastic but contrary variation trends for several key elements (such as LREEs, Zr, Hf and F) among their transition BSE zones. These two types of titanites are interpreted to crystallize coevally, and record a notable temperature and compositional change of two corresponding melts, as a response to magma mixing. E-type-II titanites (from plagioclase-poor dioritic enclaves) yield a relatively younger U-Pb age at 128 Ma, and show typical interstitial growth with narrower and lower range of Zr, total REEs contents, but higher F content and Nb/Ta ratios. Such titanites are perceived to record late-stage mingling, during which F-rich and REE-poor hybrid granodioritic magma squeezed into the incompletely consolidated dioritic enclaves with accompanying fluid-rock interaction. Unlike the dramatic elemental changes in these differentiated titanites, in-situ Nd isotopic compositions are relatively homogeneous, which in our view is a good sign of showing that isotopic equilibrium among two magma systems was more easily reached compared to elemental homogenization during the process of magma mixing and mingling. Our titanite work provides new and solid evidence to support a magma mixing genesis for Guojialing intrusion, and also presents a good case study of utilizing accessory titanite to decipher a detailed magmatic chamber process.

DOUBLE-PEAKED NARROW-LINE ACTIVE GALACTIC NUCLEI. II. THE CASE OF EQUAL PEAKS

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

Smith, K. L.; Shields, G. A.; Salviander, S.

Active galactic nuclei (AGNs) with double-peaked narrow lines (DPAGNs) may be caused by kiloparsec-scale binary AGNs, bipolar outflows, or rotating gaseous disks. We examine the class of DPAGNs in which the two narrow-line components have closely similar intensity as being especially likely to involve disks or jets. Two spectroscopic indicators support this likelihood. For DPAGNs from Smith et al., the 'equal-peaked' objects (EPAGNs) have [Ne V]/[O III]ratios lower than for a control sample of non-double-peaked AGNs. This is unexpected for a pair of normal AGNs in a galactic merger, but may be consistent with [O III] emission from a rotatingmore » ring with relatively little gas at small radii. Also, [O III]/H{beta} ratios of the redshifted and blueshifted systems in the EPAGN are more similar to each other than in a control sample, suggestive of a single ionizing source and inconsistent with the binary interpretation.« less

Polyploidization mechanisms: temperature environment can induce diploid gamete formation in Rosa sp.

PubMed

Pécrix, Yann; Rallo, Géraldine; Folzer, Hélène; Cigna, Mireille; Gudin, Serge; Le Bris, Manuel

2011-06-01

Polyploidy is an important evolutionary phenomenon but the mechanisms by which polyploidy arises still remain underexplored. There may be an environmental component to polyploidization. This study aimed to clarify how temperature may promote diploid gamete formation considered an essential element for sexual polyploidization. First of all, a detailed cytological analysis of microsporogenesis and microgametogenesis was performed to target precisely the key developmental stages which are the most sensitive to temperature. Then, heat-induced modifications in sporad and pollen characteristics were analysed through an exposition of high temperature gradient. Rosa plants are sensitive to high temperatures with a developmental sensitivity window limited to meiosis. Moreover, the range of efficient temperatures is actually narrow. 36 °C at early meiosis led to a decrease in pollen viability, pollen ectexine defects but especially the appearance of numerous diploid pollen grains. They resulted from dyads or triads mainly formed following heat-induced spindle misorientations in telophase II. A high temperature environment has the potential to increase gamete ploidy level. The high frequencies of diplogametes obtained at some extreme temperatures support the hypothesis that polyploidization events could have occurred in adverse conditions and suggest polyploidization facilitating in a global change context.

Continuum Gyrokinetic Simulations of Turbulence in a Helical Model SOL with NSTX-type parameters

NASA Astrophysics Data System (ADS)

Hammett, G. W.; Shi, E. L.; Hakim, A.; Stoltzfus-Dueck, T.

2017-10-01

We have developed the Gkeyll code to carry out 3D2V full- F gyrokinetic simulations of electrostatic plasma turbulence in open-field-line geometries, using special versions of discontinuous-Galerkin algorithms to help with the computational challenges of the edge region. (Higher-order algorithms can also be helpful for exascale computing as they reduce the ratio of communications to computations.) Our first simulations with straight field lines were done for LAPD-type cases. Here we extend this to a helical model of an SOL plasma and show results for NSTX-type parameters. These simulations include the basic elements of a scrape-off layer: bad-curvature/interchange drive of instabilities, narrow sources to model plasma leaking from the core, and parallel losses with model sheath boundary conditions (our model allows currents to flow in and out of the walls). The formation of blobs is observed. By reducing the strength of the poloidal magnetic field, the heat flux at the divertor plate is observed to broaden. Supported by the Max-Planck/Princeton Center for Plasma Physics, the SciDAC Center for the Study of Plasma Microturbulence, and DOE Contract DE-AC02-09CH11466.

Transforming common III-V/II-VI insulating building blocks into topological heterostructure via the intrinsic electric polarization

NASA Astrophysics Data System (ADS)

Zunger, Alex; Zhang, Xiuwen; Abdalla, Leonardo; Liu, Qihang

Currently known topological insulators (TIs) are limited to narrow gap compounds incorporating heavy elements, thus severely limiting the material pool available for such applications. We show how a heterovalent superlattice made of common semiconductor building blocks can transform its non-TI components into a topological heterostructure. The heterovalent nature of such interfaces sets up, in the absence of interfacial atomic exchange, a natural internal electric field that along with the quantum confinement leads to band inversion, transforming these semiconductors into a topological phase while also forming a giant Rashba spin splitting. We demonstrate this paradigm of designing TIs from ordinary semiconductors via first-principle calculations on III-V/II-VI superlattice InSb/CdTe. We illustrate the relationship between the interfacial stability and the topological transition, finding a ``window of opportunity'' where both conditions can be optimized. This work illustrates the general principles of co-evaluation of TI functionality with thermodynamic stability as a route of identifying realistic combination of common insulators that could produce topological heterostructures. This work was supported by Basic Energy Science, MSE division (Grant DE-FG02-13ER46959).

Transitional Flow in an Arteriovenous Fistula: Effect of Wall Distensibility

NASA Astrophysics Data System (ADS)

McGah, Patrick; Leotta, Daniel; Beach, Kirk; Aliseda, Alberto

2012-11-01

Arteriovenous fistulae are created surgically to provide adequate access for dialysis in patients with end-stage renal disease. Transitional flow and the subsequent pressure and shear stress fluctuations are thought to be causative in the fistula failure. Since 50% of fistulae require surgical intervention before year one, understanding the altered hemodynamic stresses is an important step toward improving clinical outcomes. We perform numerical simulations of a patient-specific model of a functioning fistula reconstructed from 3D ultrasound scans. Rigid wall simulations and fluid-structure interaction simulations using an in-house finite element solver for the wall deformations were performed and compared. In both the rigid and distensible wall cases, transitional flow is computed in fistula as evidenced by aperiodic high frequency velocity and pressure fluctuations. The spectrum of the fluctuations is much more narrow-banded in the distensible case, however, suggesting a partial stabilizing effect by the vessel elasticity. As a result, the distensible wall simulations predict shear stresses that are systematically 10-30% lower than the rigid cases. We propose a possible mechanism for stabilization involving the phase lag in the fluid work needed to deform the vessel wall. Support from an NIDDK R21 - DK08-1823.

Application and Analysis of the Isoelectronic Line Ratio Temperature Diagnostic in a Planar Ablating-Plasma Experiment at the National Ignition Facility

NASA Astrophysics Data System (ADS)

Epstein, R.; Rosenberg, M. J.; Solodov, A. A.; Myatt, J. F.; Regan, S. P.; Seka, W.; Hohenberger, M.; Barrios, M. A.; Moody, J. D.

2015-11-01

The Mn/Co isoelectronic emission-line ratio from a microdot source in planar CH foil targets was measured to infer the electron temperature (Te) in the ablating plasma during two-plasmon-decay experiments at the National Ignition Facility (NIF). We examine the systematic uncertainty in the Te estimate based on the temperature and density sensitivities of the line ratio in conjunction with plausible density constraints, and its contribution to the total Te estimate uncertainty. The potential advantages of alternative microdot elements (e.g., Ti/Cr and Sc/V) are considered. The microdot mass was selected to provide ample line strength while minimizing the effect of self-absorption on the line emission, which is of particular concern, given the narrow linewidths of mid- Z emitters at subcritical electron densities. Atomic line-formation theory and detailed atomic-radiative simulations show that the straight forward interpretation of the isoelectronic ratio solely in terms of its temperature independence remains valid with lines of moderate optical thickness (up to ~ 10) at line center. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

Extraction of mineral elements from inedible wastes of biological components of a life-support system and their utilization for plant nutrition

NASA Astrophysics Data System (ADS)

Gribovskaya, I. V.; Gladchenko, I. A.; Zinenko, G. K.

Two methods of extracting mineral elements from otherwise deadlock products of a life-support system are presented. We describe first optimum conditions for recovering elements by water extraction from dry wastes of plants, biomass ash, and solid human wastes after passing them through the catalytic furnace; and, second, we describe acid extracts of biogenous elements by 1N and 2N HNO_3 from these products. Ways to use the extracts of elements in plant nutrition are considered in order to increase the extent to which the mineral loop of a life-support system can be closed.

Enhanced radiation-induced narrow channel effects in 0.13-{\\boldsymbol{\\mu }}{\\rm{m}} PDSOI nMOSFETs with shallow trench isolation

NASA Astrophysics Data System (ADS)

Zhang, Meng-Ying; Hu, Zhi-Yuan; Bi, Da-Wei; Dai, Li-Hua; Zhang, Zheng-Xuan

2018-02-01

Not Available Project supported by the Weapon Equipment Pre-Research Foundation of China (Grant No. 9140A11020114ZK34147) and the Shanghai Municipal Natural Science Foundation, China (Grant No. 15ZR1447100).

Building with integral solar-heat storage--Starkville, Mississippi

NASA Technical Reports Server (NTRS)

1981-01-01

Column supporting roof also houses rock-storage bin of solar-energy system supplying more than half building space heating load. Conventional heaters supply hot water. Since bin is deeper and narrower than normal, individual pebble size was increased to keep airflow resistance at minimum.

The Case for an Arts-Based Curriculum

ERIC Educational Resources Information Center

Stuht, Amy Colcord; Gates, Janie Yuguchi

2007-01-01

Continuation schools were developed to enable students to continue earning a high school diploma while they worked, often full time, to support themselves and their families. Traditionally, continuation schools were home to poor teachers, narrowed curriculum and an unwelcoming culture. Intuitively, students attending today's continuation schools…

Rapid evolution of regulatory element libraries for tunable transcriptional and translational control of gene expression.

PubMed

Jin, Erqing; Wong, Lynn; Jiao, Yun; Engel, Jake; Holdridge, Benjamin; Xu, Peng

2017-12-01

Engineering cell factories for producing biofuels and pharmaceuticals has spurred great interests to develop rapid and efficient synthetic biology tools customized for modular pathway engineering. Along the way, combinatorial gene expression control through modification of regulatory element offered tremendous opportunity for fine-tuning gene expression and generating digital-like genetic circuits. In this report, we present an efficient evolutionary approach to build a range of regulatory control elements. The reported method allows for rapid construction of promoter, 5'UTR, terminator and trans -activating RNA libraries. Synthetic overlapping oligos with high portion of degenerate nucleotides flanking the regulatory element could be efficiently assembled to a vector expressing fluorescence reporter. This approach combines high mutation rate of the synthetic DNA with the high assembly efficiency of Gibson Mix. Our constructed library demonstrates broad range of transcriptional or translational gene expression dynamics. Specifically, both the promoter library and 5'UTR library exhibits gene expression dynamics spanning across three order of magnitude. The terminator library and trans -activating RNA library displays relatively narrowed gene expression pattern. The reported study provides a versatile toolbox for rapidly constructing a large family of prokaryotic regulatory elements. These libraries also facilitate the implementation of combinatorial pathway engineering principles and the engineering of more efficient microbial cell factory for various biomanufacturing applications.

Chemical and boron isotopic composition of tourmaline from the Mariinsky emerald deposit, Central Urals, Russia

NASA Astrophysics Data System (ADS)

Baksheev, Ivan A.; Trumbull, Robert B.; Popov, Mikhail P.; Erokhin, Yuri V.; Kudryavtseva, Olesya E.; Yapaskurt, Vasily O.; Khiller, Vera V.; Vovna, Galina M.; Kiselev, Vladimir I.

2018-04-01

Tourmaline is abundant at the Mariinsky schist-hosted emerald deposit in the Central Urals, Russia, both in emerald-bearing phlogopite veins (type 1) and later, emerald-free pockets, lenses, and veinlets cutting the phlogopite veins (type 2). The Ca content in tourmaline is influenced by the host rocks (ultramafic and mafic rocks), associated minerals, and minerals crystallized before tourmaline (amphibole, fluorite, margarite). The Na concentration in tourmaline depends on the presence or absence of paragonite, and the association with micas also strongly influences the contents of Li, Zn, Ni, and Co in tourmaline. Type 1 tourmalines associated with phlogopite are relatively depleted in these elements, whereas type 2 tourmalines associated with margarite or paragonite are enriched. Some differences in isomorphic substitutions along with the trace element composition (Zn, V, Sr, Co, REE) may have value in exploration of emerald-bearing and emerald-free veins in schist-hosted emerald deposits. The δ11B values in tourmaline of all types fall in a narrow total range from -11.3 to -8.4‰. These values, combined with a mineralization temperature of 420-360 °C, yield an estimated δ11B fluid composition of -7.4 to -6.8‰ suggesting a mixed source of boron, likely dominated from the granitic rocks surrounding the emerald belt. The narrow range of B-isotope compositions in tourmaline from throughout the Mariinsky deposit suggests a well-mixed hydrothermal system.

An experimental investigation of high temperature superconducting microstrip antennas at K- and Ka-band frequencies. Ph.D. Thesis Final Report

NASA Technical Reports Server (NTRS)

Richard, Mark A.

1993-01-01

The recent discovery of high temperature superconductors (HTS) has generated a substantial amount of interest in microstrip antenna applications. However, the high permittivity of substrates compatible with HTS results in narrow bandwidths and high patch edge impedances of such antennas. To investigate the performance of superconducting microstrip antennas, three antenna architectures at K and Ka-band frequencies are examined. Superconducting microstrip antennas that are directly coupled, gap coupled, and electromagnetically coupled to a microstrip transmission line were designed and fabricated on lanthanum aluminate substrates using YBa2Cu3O7 superconducting thin films. For each architecture, a single patch antenna and a four element array were fabricated. Measurements from these antennas, including input impedance, bandwidth, patterns, efficiency, and gain are presented. The measured results show usable antennas can be constructed using any of the architectures. All architectures show excellent gain characteristics, with less than 2 dB of total loss in the four element arrays. Although the direct and gap coupled antennas are the simplest antennas to design and fabricate, they suffer from narrow bandwidths. The electromagnetically coupled antenna, on the other hand, allows the flexibility of using a low permittivity substrate for the patch radiator, while using HTS for the feed network, thus increasing the bandwidth while effectively utilizing the low loss properties of HTS. Each antenna investigated in this research is the first of its kind reported.

Design Change Model for Effective Scheduling Change Propagation Paths

NASA Astrophysics Data System (ADS)

Zhang, Hai-Zhu; Ding, Guo-Fu; Li, Rong; Qin, Sheng-Feng; Yan, Kai-Yin

2017-09-01

Changes in requirements may result in the increasing of product development project cost and lead time, therefore, it is important to understand how requirement changes propagate in the design of complex product systems and be able to select best options to guide design. Currently, a most approach for design change is lack of take the multi-disciplinary coupling relationships and the number of parameters into account integrally. A new design change model is presented to systematically analyze and search change propagation paths. Firstly, a PDS-Behavior-Structure-based design change model is established to describe requirement changes causing the design change propagation in behavior and structure domains. Secondly, a multi-disciplinary oriented behavior matrix is utilized to support change propagation analysis of complex product systems, and the interaction relationships of the matrix elements are used to obtain an initial set of change paths. Finally, a rough set-based propagation space reducing tool is developed to assist in narrowing change propagation paths by computing the importance of the design change parameters. The proposed new design change model and its associated tools have been demonstrated by the scheduling change propagation paths of high speed train's bogie to show its feasibility and effectiveness. This model is not only supportive to response quickly to diversified market requirements, but also helpful to satisfy customer requirements and reduce product development lead time. The proposed new design change model can be applied in a wide range of engineering systems design with improved efficiency.

Dynamic surface electronic reconstruction as symmetry-protected topological orders in topological insulator Bi2Se3

NASA Astrophysics Data System (ADS)

Shu, G. J.; Liou, S. C.; Karna, S. K.; Sankar, R.; Hayashi, M.; Chou, F. C.

2018-04-01

The layered narrow-band-gap semiconductor Bi2Se3 is composed of heavy elements with strong spin-orbital coupling, which has been identified both as a good candidate for a thermoelectric material with high thermoelectric figure of merit (Z T ) and as a topological insulator of the Z2 type with a gapless surface band in a Dirac-cone shape. The existence of a conjugated π -bond system on the surface of each Bi2Se3 quintuple layer is proposed based on an extended valence bond model with valence electrons distributed in the hybridized orbitals. Supporting experimental evidence of a two-dimensional (2D) conjugated π -bond system on each quintuple layer of Bi2Se3 is provided using electron energy-loss spectroscopy and electron density mapping through inverse Fourier transform of x-ray diffraction data. Quantum chemistry calculations support the π -bond existence between partially filled 4 pz orbitals of Se via side-to-side orbital overlap positively. The conjugated π -bond system on the surface of each quintuple Bi2Se3 layer is proposed to be similar to that found in graphite (graphene) and responsible for the unique 2D conduction mechanism. The van der Waals (vdW) attractive force between quintuple layers is interpreted to be coming from the antiferroelectrically ordered effective electric dipoles, which are constructed with π -bond trimer pairs on Se layers across the vdW gap of minimized Coulomb repulsion.

Narrowing the wingless-2 mutation to a 227 kb candidate region on chicken chromosome 12

PubMed Central

Webb, A E; Youngworth, I A; Kaya, M; Gitter, C L; O’Hare, E A; May, B; Cheng, H H; Delany, M E

2018-01-01

ABSTRACT Wingless-2 (wg-2) is an autosomal recessive mutation in chicken that results in an embryonic lethal condition. Affected individuals exhibit a multisystem syndrome characterized by absent wings, truncated legs, and craniofacial, kidney, and feather malformations. Previously, work focused on phenotype description, establishing the autosomal recessive pattern of Mendelian inheritance and placing the mutation on an inbred genetic background to create the congenic line UCD Wingless-2.331. The research described in this paper employed the complementary tools of breeding, genetics, and genomics to map the chromosomal location of the mutation and successively narrow the size of the region for analysis of the causative element. Specifically, the wg-2 mutation was initially mapped to a 7 Mb region of chromosome 12 using an Illumina 3 K SNP array. Subsequent SNP genotyping and exon sequencing combined with analysis from improved genome assemblies narrowed the region of interest to a maximum size of 227 kb. Within this region, 3 validated and 3 predicted candidate genes are found, and these are described. The wg-2 mutation is a valuable resource to contribute to an improved understanding of the developmental pathways involved in chicken and avian limb development as well as serving as a model for human development, as the resulting syndrome shares features with human congenital disorders. PMID:29562287

Estimating the vibration level of an L-shaped beam using power flow techniques

NASA Technical Reports Server (NTRS)

Cuschieri, J. M.; Mccollum, M.; Rassineux, J. L.; Gilbert, T.

1986-01-01

The response of one component of an L-shaped beam, with point force excitation on the other component, is estimated using the power flow method. The transmitted power from the source component to the receiver component is expressed in terms of the transfer and input mobilities at the excitation point and the joint. The response is estimated both in narrow frequency bands, using the exact geometry of the beams, and as a frequency averaged response using infinite beam models. The results using this power flow technique are compared to the results obtained using finite element analysis (FEA) of the L-shaped beam for the low frequency response and to results obtained using statistical energy analysis (SEA) for the high frequencies. The agreement between the FEA results and the power flow method results at low frequencies is very good. SEA results are in terms of frequency averaged levels and these are in perfect agreement with the results obtained using the infinite beam models in the power flow method. The narrow frequency band results from the power flow method also converge to the SEA results at high frequencies. The advantage of the power flow method is that detail of the response can be retained while reducing computation time, which will allow the narrow frequency band analysis of the response to be extended to higher frequencies.

78 FR 54242 - 36(b)(1) Arms Sales Notification

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-03

... elements of logistical and program support. The estimated cost is $1.2 billion. This proposed sale will... support services, and other related elements of logistical and program support. (iv) Military Department... logistical support to sustain the combat and operational readiness of its existing aircraft fleet. The...

Recurrence quantification analysis to characterize cyclical components of environmental elemental exposures during fetal and postnatal development

PubMed Central

Austin, Christine; Gennings, Chris; Tammimies, Kristiina; Bölte, Sven; Arora, Manish

2017-01-01

Environmental exposures to essential and toxic elements may alter health trajectories, depending on the timing, intensity, and mixture of exposures. In epidemiologic studies, these factors are typically analyzed as a function of elemental concentrations in biological matrices measured at one or more points in time. Such an approach, however, fails to account for the temporal cyclicity in the metabolism of environmental chemicals, which if perturbed may lead to adverse health outcomes. Here, we conceptualize and apply a non-linear method–recurrence quantification analysis (RQA)–to quantify cyclical components of prenatal and early postnatal exposure profiles for elements essential to normal development, including Zn, Mn, Mg, and Ca, and elements associated with deleterious health effects or narrow tolerance ranges, including Pb, As, and Cr. We found robust evidence of cyclical patterns in the metabolic profiles of nutrient elements, which we validated against randomized twin-surrogate time-series, and further found that nutrient dynamical properties differ from those of Cr, As, and Pb. Furthermore, we extended this approach to provide a novel method of quantifying dynamic interactions between two environmental exposures. To achieve this, we used cross-recurrence quantification analysis (CRQA), and found that elemental nutrient-nutrient interactions differed from those involving toxicants. These rhythmic regulatory interactions, which we characterize in two geographically distinct cohorts, have not previously been uncovered using traditional regression-based approaches, and may provide a critical unit of analysis for environmental and dietary exposures in epidemiological studies. PMID:29112980

Narrowing the creativity gap: the moderating effects of perceived support for creativity.

PubMed

DiLiello, Trudy C; Houghton, Jeffery D; Dawley, David

2011-01-01

This article examines the role of 3 types of perceived support for creativity in moderating the relation between creative self-efficacy and self-perceived creativity. The findings suggest significant interaction effects for perceived work-group support and supervisor support, but not for perceived organizational support. This study is among the first to (a) examine the importance of perceived support for creativity in unlocking creative potential and increasing creativity in organizations and (b) use interaction terms in structural equation modeling (SEM) to investigate moderator effects in an applied research setting. These results imply that organizational interventions focused on training supervisors and work-group members to support creativity in the workplace may be more effective than broader and less focused interventions at the organizational level.

A finite element method with overlapping meshes for free-boundary axisymmetric plasma equilibria in realistic geometries

NASA Astrophysics Data System (ADS)

Heumann, Holger; Rapetti, Francesca

2017-04-01

Existing finite element implementations for the computation of free-boundary axisymmetric plasma equilibria approximate the unknown poloidal flux function by standard lowest order continuous finite elements with discontinuous gradients. As a consequence, the location of critical points of the poloidal flux, that are of paramount importance in tokamak engineering, is constrained to nodes of the mesh leading to undesired jumps in transient problems. Moreover, recent numerical results for the self-consistent coupling of equilibrium with resistive diffusion and transport suggest the necessity of higher regularity when approximating the flux map. In this work we propose a mortar element method that employs two overlapping meshes. One mesh with Cartesian quadrilaterals covers the vacuum chamber domain accessible by the plasma and one mesh with triangles discretizes the region outside. The two meshes overlap in a narrow region. This approach gives the flexibility to achieve easily and at low cost higher order regularity for the approximation of the flux function in the domain covered by the plasma, while preserving accurate meshing of the geometric details outside this region. The continuity of the numerical solution in the region of overlap is weakly enforced by a mortar-like mapping.

School Tort Law in Illinois.

ERIC Educational Resources Information Center

Menacker, Julius

1990-01-01

Illinois tort policy has swung from supporting the sovereign immunity of school districts, to completely striking down sovereign immunity, to narrowing conditions in which districts and employees could be liable. Advises Illinois and other states with similar problems to develop legislation and court precedents to reduce the complexity of tort…

Counties Without a Physician.

ERIC Educational Resources Information Center

Getz, Virginia

1982-01-01

Uses a budgeting technique to determine if free-market incentives or forces would provide an economic base sufficient to support medical professionals who might practice in the approximately 140 U.S. counties that lack a physician (located mainly in a narrow band from west Texas north through South Dakota). (AH)

Joint Enabling Capabilities Command

Science.gov Websites

Executive Director Chief of Staff Joint Planning Support Element Joint Communications Support Element mission Joint Enabling Capabilities Command provides decisive joint communications, planning and public and responsive support for joint communications, planning and public affairs. Priorities * Deliver

GAUSSIAN BEAM LASER RESONATOR PROGRAM

NASA Technical Reports Server (NTRS)

Cross, P. L.

1994-01-01

In designing a laser cavity, the laser engineer is frequently concerned with more than the stability of the resonator. Other considerations include the size of the beam at various optical surfaces within the resonator or the performance of intracavity line-narrowing or other optical elements. Laser resonators obey the laws of Gaussian beam propagation, not geometric optics. The Gaussian Beam Laser Resonator Program models laser resonators using Gaussian ray trace techniques. It can be used to determine the propagation of radiation through laser resonators. The algorithm used in the Gaussian Beam Resonator program has three major components. First, the ray transfer matrix for the laser resonator must be calculated. Next calculations of the initial beam parameters, specifically, the beam stability, the beam waist size and location for the resonator input element, and the wavefront curvature and beam radius at the input surface to the first resonator element are performed. Finally the propagation of the beam through the optical elements is computed. The optical elements can be modeled as parallel plates, lenses, mirrors, dummy surfaces, or Gradient Index (GRIN) lenses. A Gradient Index lens is a good approximation of a laser rod operating under a thermal load. The optical system may contain up to 50 elements. In addition to the internal beam elements the optical system may contain elements external to the resonator. The Gaussian Beam Resonator program was written in Microsoft FORTRAN (Version 4.01). It was developed for the IBM PS/2 80-071 microcomputer and has been implemented on an IBM PC compatible under MS DOS 3.21. The program was developed in 1988 and requires approximately 95K bytes to operate.

Apparatus and method for the spectrochemical analysis of liquids using the laser spark

DOEpatents

Cremers, David A.; Radziemski, Leon J.; Loree, Thomas R.

1990-01-01

A method and apparatus for the qualitative and quantitative spectroscopic investigation of elements present in a liquid sample using the laser spark. A series of temporally closely spaced spark pairs is induced in the liquid sample utilizing pulsed electromagnetic radiation from a pair of lasers. The light pulses are not significantly absorbed by the sample so that the sparks occur inside of the liquid. The emitted light from the breakdown events is spectrally and temporally resolved, and the time period between the two laser pulses in each spark pair is adjusted to maximize the signal-to-noise ratio of the emitted signals. In comparison with the single pulse technique, a substantial reduction in the limits of detectability for many elements has been demonstrated. Narrowing of spectral features results in improved discrimination against interfering species.

Apparatus and method for the spectrochemical analysis of liquids using the laser spark

DOEpatents

Cremers, D.A.; Radziemski, L.J.; Loree, T.R.

1984-05-01

A method and apparatus are disclosed for the qualitative and quantitative spectroscopic investigation of elements present in a liquid sample using the laser spark. A series of temporally closely spaced spark pairs is induced in the liquid sample utilizing pulsed electromagnetic radiation from a pair of lasers. The light pulses are not significantly absorbed by the sample so that the sparks occur inside of the liquid. The emitted light from the breakdown events is spectrally and temporally resolved, and the time period between the two laser pulses in each spark pair is adjusted to maximize the signal-to-noise ratio of the emitted signals. In comparison with the single pulse technique, a substantial reduction in the limits of detectability for many elements has been demonstrated. Narrowing of spectral features results in improved discrimination against interfering species.

New Techniques for Investigating Properties of Energetic Solids at High Static and Dynamic Pressures.

DTIC Science & Technology

1976-09-01

fluid. For optical measurements in the regions of extremely high absorption ( lOs — io6 cm~~) thin films are required with a thickness of 500—5000L The top...round trip in the cavity. The result is a series of extremely narrow pulses, each pulse a few picoseconds ( lO ~~2 seconds) in duration and separated...electronic pulsar and electro—optic selection elements, it is possible to extract a single picosecond pulse from the train. This is I achieved by placing a

MBE Growth, Characterization and Electronic Device Processing of HgCdTe, HgZnTe, Related Heterojunctions and HgCdTe-CdTe Superlattices

DTIC Science & Technology

1987-06-30

metal lattice sites using the liquid phase epitaxy. However, group V elements have not been successfully Incorporated Into MBE grown HgCdTe layer as...narrow-gap side was first Both groups used the liquid pweepitaxy (LPE) growth made with a thicknem of 2 to 3/pm before the growth condi- technique and...higher quasiequilibrium pressure than with the shutter opened. This study shows that with the particular geometry 27 used the time constant required

Kinematics of a vertical axis wind turbine with a variable pitch angle

NASA Astrophysics Data System (ADS)

Jakubowski, Mateusz; Starosta, Roman; Fritzkowski, Pawel

2018-01-01

A computational model for the kinematics of a vertical axis wind turbine (VAWT) is presented. A H-type rotor turbine with a controlled pitch angle is considered. The aim of this solution is to improve the VAWT productivity. The discussed method is related to a narrow computational branch based on the Blade Element Momentum theory (BEM theory). The paper can be regarded as a theoretical basis and an introduction to further studies with the application of BEM. The obtained torque values show the main advantage of using the variable pitch angle.

A mirror for science.

PubMed

Jasanoff, Sheila

2014-01-01

Early conceptions of the public understanding of science suffered from a narrow framing of what science means and a presumption that science is divided from its publics by walls of ignorance and indifference. Those assumptions amplified misunderstanding and led to faulty policies. It is time to reopen each element in the term "public understanding of science" to renewed reflection. This journal can advance that goal by encouraging research on actual rather than imagined public responses to science, on representations of science in the public sphere, and on interactions between science, technology and society.

Piezoelectric film load cell robot collision detector

DOEpatents

Lembke, J.R.

1988-03-15

A piezoelectric load cell which can be utilized for detecting collisions and obstruction of a robot arm end effector includes a force sensing element of metallized polyvinylidene fluoride (PVDF) film. The piezoelectric film sensing element and a resilient support pad are clamped in compression between upper and lower plates. The lower plate has a central recess in its upper face for supporting the support pad and sensing element, while the upper plate has a corresponding central projection formed on its lower face for bearing on the sensing element and support pad. The upper and lower plates are dowelled together for concentric alignment and screwed together. The upper and lower plates are also adapted for mounting between the robot arm wrist and end effector. 3 figs.

Piezoelectric film load cell robot collision detector

DOEpatents

Lembke, John R.

1989-04-18

A piezoelectric load cell which can be utilized for detecting collisions and obstruction of a robot arm end effector includes a force sensing element of metallized polyvinylidene fluoride (PVDF) film. The piezoelectric film sensing element and a resilient support pad are clamped in compression between upper and lower plates. The lower plate has a central recess in its upper face for supporting the support pad and sensing element, while the upper plate has a corresponding central projection formed on its lower face for bearing on the sensing element and support pad. The upper and lower plates are dowelled together for concentric alignment and screwed together. The upper and lower plates are also adapted for mounting between the robot arm wrist and end effector.

Piezoelectric film load cell robot collision detector

DOEpatents

Lembke, J.R.

1989-04-18

A piezoelectric load cell which can be utilized for detecting collisions and obstruction of a robot arm end effector includes a force sensing element of metallized polyvinylidene fluoride (PVDF) film. The piezoelectric film sensing element and a resilient support pad are clamped in compression between upper and lower plates. The lower plate has a central recess in its upper face for supporting the support pad and sensing element, while the upper plate has a corresponding central projection formed on its lower face for bearing on the sensing element and support pad. The upper and lower plates are doweled together for concentric alignment and screwed together. The upper and lower plates are also adapted for mounting between the robot arm wrist and end effector. 3 figs.

Colorado's Singular "No"

ERIC Educational Resources Information Center

Wiedeman, Reeves

2008-01-01

Supporters of affirmative action may have finally found a way to defeat state ballot measures that would ban such programs: Latch onto an inspirational presidential candidate with piles of cash and an unprecedented voter-turnout machine. Those activists won a narrow victory in Colorado this month, when 50.7 percent of voters made the state the…

Attitudes toward Family Life Education: A Survey of Israeli Arab Teachers.

ERIC Educational Resources Information Center

Oz, Sheri

1991-01-01

Investigated Israeli Arab teachers' attitudes toward inclusion of family life education program in schools, possible subject areas for instruction, and parent involvement. Results indicated high degree of support for family life education and narrow range of subject areas considered appropriate for Arab classes. Parent involvement was considered…

GYPCHEK biological insecticide for the gypsy moth

Treesearch

John D. Podgwaite

1999-01-01

With administrative and financial support from its State and Private Forestry division, the USDA Forest Service has directed much effort toward developing viral pesticides that kill forest insect pests. Most environmentally benign viral pesticides are narrow host-range products (Groner 1986) that are most useful in situations where environmental concerns are paramount...

76 FR 16365 - Approval and Promulgation of Implementation Plans; Washington: Correction

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-23

... precursors to a NAAQS pollutant: Department of Ecology (Ecology): WAC 173-400-040 (except WAC 173- 400-040(1..., Ecology and SWCAA stated their support of EPA's approval of this correction and narrowing of the... address, as appropriate, disproportionate human health or environmental effects, using practicable and...

Algebra Homework: A Sandwich!

ERIC Educational Resources Information Center

Jackson, D. Bruce

2014-01-01

At a time when the debate continues over whether homework is overused, optional, or essential or favors well-off students over those with little home support, teachers must understand ways in which effective homework strategies can help narrow the achievement gap. Vatterott (2009, p. 94) argues convincingly that the "old paradigm" of…

Chronic Absenteeism and Preschool Children's Executive Functioning Skills Development

ERIC Educational Resources Information Center

Fuhs, Mary Wagner; Nesbitt, Kimberly Turner; Jackson, Hannah

2018-01-01

Investments in preschool programs for children from disadvantaged backgrounds have historically been supported by research showing that these programs help children build school readiness skills and narrow the income-achievement gap. However, results from recent studies of the links between preschool participation and increases in school readiness…

Framework for Transforming Departmental Culture to Support Educational Innovation

ERIC Educational Resources Information Center

Corbo, Joel C.; Reinholz, Daniel L.; Dancy, Melissa H.; Deetz, Stanley; Finkelstein, Noah

2016-01-01

This paper provides a research-based framework for promoting institutional change in higher education. To date, most educational change efforts have focused on relatively narrow subsets of the university system (e.g., faculty teaching practices or administrative policies) and have been largely driven by implicit change logics; both of these…

Beyond Cognitivisation: Creating Collectively Constructed Imaginary Situations for Supporting Learning and Development

ERIC Educational Resources Information Center

Fleer, Marilyn; Peers, Chris

2012-01-01

Renewed emphasis in Western political and economic debate on improving outcomes and reducing play opportunities are resulting in a "cognitivisation" of early childhood education, which is at odds with parallel attention to outcomes for creativity and imagination. Defining this "cognitivisation" as a narrowing of acceptable performance descriptions…

Students from Australian Universities Studying Abroad: A Demographic Profile

ERIC Educational Resources Information Center

Nerlich, Steve

2015-01-01

Australia is one of many countries to encourage its students to study abroad and hence develop a global perspective. Traditionally, students who have pursued this option represented a relatively privileged and demographically narrow group. More recently, governments and other agencies have been offering funding support with the aim of…

Lay food and health worker involvement in community nutrition and dietetics in England: roles, responsibilities and relationship with professionals.

PubMed

Kennedy, L A; Milton, B; Bundred, P

2008-06-01

Community-based food initiatives have developed in recent years with the aim of engaging previously 'hard to reach' groups. Lay workers engaged in community nutrition activities are promoted as a cost-effective mechanism for reaching underserved groups. The main objective of the study was to explore perceptions and definitions of lay food and health worker (LFHW) helping roles within the context of National Health Service (NHS) community nutrition and dietetic services in order to define the conceptual and practical elements of this new role and examine the interface with professional roles. Interpretive qualitative inquiry; semi-structured interviews with LFHW and NHS professionals employed by community-based programmes, serving 'hard-to-reach' neighbourhoods, across England. A total sampling framework was used to capture all existing and 'fully operational' lay food initiatives in England at the commencement of fieldwork (January 2002). In total, 29 professionals and 53 LFHWs were interviewed across 15 of the 18 projects identified. Although all 15 projects shared a universal goal, to promote healthy eating, this was achieved through a limited range of approaches, characterized by a narrow, individualistic focus. Lay roles spanned three broad areas: nutrition education; health promotion; and administration and personal development. Narratives from both professionals and LFHWs indicated that the primary role for LFHWs was to encourage dietary change by translating complex messages into credible and culturally appropriate advice. This research confirms the emerging discipline involving lay helping within the NHS and community dietetics. The primary role of LFHWs in the 15 projects involved was to support existing NHS services to promote healthy eating amongst 'hard to reach' communities. The activities undertaken by LFHWs are strongly influenced by professionals and the NHS. Inherent to this is a fairly narrow interpretation of health, resulting in a limited range of practice.

Calibration and Performance of the Michelson Doppler Imager on SOHO.

NASA Astrophysics Data System (ADS)

Zayer, I.; Morrison, M.; Tarbell, T. D.; Title, A.; Wolfson, C. J.; MDI Engineering Team; Bogart, R. S.; Bush, R. I.; Hoeksema, J. T.; Duvall, T.; Sa, L. A. D.; Scherrer, P. H.; Schou, J.

1996-05-01

The Michelson Doppler Imager (MDI) instrument probes the interior of the Sun by measuring the photospheric manifestations of solar oscillations. MDI was launched in December, 1995, on the Solar and Heliospheric Observatory (SOHO) and has been successfully observing the Sun since then. The instrument images the Sun on a 1024 x 1024 pixel CCD camera through a series of increasingly narrow spectral filters. The final elements, a pair of tunable Michelson interferometers, enable MDI to record filtergrams with FWHM bandwidth of 94 m Angstroms with a resolution of 4 arcseconds over the whole disk. Images can also be collected in MDI's higher resolution (1.25 arcsecond) field centered about 160 arcseconds north of the equator. An extensive calibration program has verified the end-to-end performance of the instrument in flight. MDI is working very well; we present the most important calibration results and a sample of early science observations. The Image Stabilization System (ISS) maintains overall pointing to better than ca. 0.01 arcsec, while the ISS' diagnostic mode allows us to measure spectrally narrow pointing jitter down to less than 1 mili-arcsec. We have confirmed the linearity of each CCD pixel to lie within 0.5%\\ (the FWHM of the distribution is 0.2% ), and have to date not detected any contamination on the detector, which is cooled to -72 C. The noise in a single Dopplergram is of the order of 20 m/s, and initial measurements of transverse velocities are reliable to 100 m/s. The sensitivity of magnetograms reach 5G in a 10 minute average (15G in a single magnetogram). MDI's primary observable, the p-modes from full-disk medium-l data, are of very high quality out to l=300 as seen in the initial l-nu diagram. The SOI-MDI program is supported by NASA contract NAG5-3077.

Bevel gear driver and method having torque limit selection

NASA Technical Reports Server (NTRS)

Cook, Joseph S., Jr. (Inventor)

1994-01-01

This invention comprises a torque drive mechanism utilizing axially translatable, mutually engageable transmission members having mating crown gears, driven and driving members with a three-element drive train being biased together by resilient means or by a fluid actuator system, the apparatus being operable to transmit a precisely controlled degree of torque to a driven member. The apparatus is applicable for use in hand tools and as a replacement for impact torque drivers, torque wrenches, motorized screw drivers, or the like, wherein the applied torque must be precisely controlled or limited. The bevel torque drive includes a drive gear which is axially displaceable and rotatable within cylindrical driver housing, a rotatable intermediate gear, and an output gear. Key rotationally secures displaceable gear with respect to input shaft but permits axial movement therebetween. A thrust bearing is preferably connected to the lower end of shaft for support to reduce play and friction between shaft and a transmission joint disc during rotation of the gear train. Coaxially mounted coiled spring is footed against displaceable gear for biasing the displaceable gear toward and into engagement with the intermediate gear for driving intermediate gear and output gear. Torque control is achieved by the use of straight or spiral beveled gears which are of configurations adapted to withdraw from mutual engagement upon the torque exceeding a predetermined limit. The novel, advantageous features of the invention include the configuration of the mating, crown gear sets and the axially translatable, slidable drive gear. The mechanism is capable of transmitting a high degree of torque within a narrow, compact transmission housing. The compact size and narrow, elongated configuration of the housing is particularly applicable for use in hand tools and in multiple torque driver mechanisms in which it is necessary to drive multiple fasteners which are located in close proximity. Prior torque drivers such as 'click-type' torque wrenches do not actually limit torque application but only provide an audible warning that the limit has been reached.

Marine light attack helicopter close air support trainer for situation awareness

DTIC Science & Technology

2017-06-01

environmental elements outside the aircraft. The initial environment elements included in the trainer are those relating directly to the CAS execution...ambient environmental elements. These elements were limited the few items required to create a virtual environment . The terrain is simulated to...words) In today’s dynamic combat environment , the importance of Close Air Support (CAS) has increased significantly due to a greater need to avoid

Deformations of temporary wooden supports used to reduce building deflections in mining areas

NASA Astrophysics Data System (ADS)

Gromysz, Krzysztof

2018-04-01

Temporary supports, consisting of a stack of wooden elements and a hydraulic jack, are used in the process of removing deflections in buildings with one to three aboveground floors in mining areas. During uneven raising, the supports are loaded monotonically, unloaded and loaded cyclically. Laboratory tests were designed for the supports. For the investigated range of loads of 0 to 400 kN, under a growing load, a linear relationship exists between a load and the change in the stack length, which signifies that the deformations of wooden elements and displacements related to their mutual interactions increase proportionally. A seemingly higher stack stiffness is seen at the beginning of the unloading process and for cyclical loads, meaning that in this phase of loading, the material deformation of the wooden elements and the jack is responsible for changing the jack length in this load phase, with a negligible presence of mutual displacements of wooden elements. The support, after being unloaded, returns to the initial position and its permanent deformations are not observed. The stiffness of a temporary support decreases as the height of the stack of wooden elements increases.

Process for oxidation of hydrogen halides to elemental halogens

DOEpatents

Lyke, Stephen E.

1992-01-01

An improved process for generating an elemental halogen selected from chlorine, bromine or iodine, from a corresponding hydrogen halide by absorbing a molten salt mixture, which includes sulfur, alkali metals and oxygen with a sulfur to metal molar ratio between 0.9 and 1.1 and includes a dissolved oxygen compound capable of reacting with hydrogen halide to produce elemental halogen, into a porous, relatively inert substrate to produce a substrate-supported salt mixture. Thereafter, the substrate-supported salt mixture is contacted (stage 1) with a hydrogen halide while maintaining the substrate-supported salt mixture during the contacting at an elevated temperature sufficient to sustain a reaction between the oxygen compound and the hydrogen halide to produce a gaseous elemental halogen product. This is followed by purging the substrate-supported salt mixture with steam (stage 2) thereby recovering any unreacted hydrogen halide and additional elemental halogen for recycle to stage 1. The dissolved oxygen compound is regenerated in a high temperature (stage 3) and an optical intermediate temperature stage (stage 4) by contacting the substrate-supported salt mixture with a gas containing oxygen whereby the dissolved oxygen compound in the substrate-supported salt mixture is regenerated by being oxidized to a higher valence state.

78 FR 59342 - 36(b)(1) Arms Sales Notification

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-26

... related elements of logistical and program support. (iv) Military Department: Air Force (QAI) (v) Prior... contractor engineering, technical and logistics support services, and other related elements of logistical and program support. The estimated cost is $60 million. This proposed sale will contribute to the...

Preparation, characterization, and activity of α-Ti(HPO4)2 supported metallocene catalysts

NASA Astrophysics Data System (ADS)

Shi, Yasai; Yuan, Yuan; Xu, Qinghong; Yi, Jianjun

2016-10-01

A series of heterogeneous catalysts by loading metallocenes on surface of α-Ti(HPO4)2, a kind of solid acid, has been synthesized. Polymerization of alkenes, including ethylene and propylene, based on participation of the heterogeneous catalysts were studied and the results were compared to metallocenes supported on silica gel, α-Zr(HPO4)2 and clay. Higher catalytic activity, larger polymer molecular weight and narrow distribution of polymer molecular weight were obtained. Acidic strength of the support and its influence to metallocenes were studied to discover intrinsic factors in the polymerizations.

Dynamic formation and magnetic support of loop or arcade prominences

NASA Technical Reports Server (NTRS)

Vanhoven, Gerard; Mok, Y.; Drake, J. F.

1992-01-01

The results of model dynamic simulations of the formation and support of a narrow prominence at the apex of a coronal magnetic loop or arcade are described. The condensation process proceeds via an initial radiative cooling and pressure drop, and a secondary siphon flow from the dense chromospheric ends. The antibuoyancy effect as the prominence forms causes a bending of a confining magnetic field, which propagates toward the semirigid ends of the magnetic loop. Thus, a wide magnetic 'hammock' or well (of a normal polarity Kippenhahn-Schlueter type) is formed, which supports the prominence at or near the field apex.

Effectiveness of Multimedia Elements in Computer Supported Instruction: Analysis of Personalization Effects, Students' Performances and Costs

ERIC Educational Resources Information Center

Zaidel, Mark; Luo, XiaoHui

2010-01-01

This study investigates the efficiency of multimedia instruction at the college level by comparing the effectiveness of multimedia elements used in the computer supported learning with the cost of their preparation. Among the various technologies that advance learning, instructors and students generally identify interactive multimedia elements as…

35. DETAILS AND SECTIONS OF FUEL ELEMENT SUPPORT PLATFORM, FUEL ...

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

35. DETAILS AND SECTIONS OF FUEL ELEMENT SUPPORT PLATFORM, FUEL ELEMENT HOLDER, TRIP MECHANISM COVER, AND OTHER DETAILS. F.C. TORKELSON DRAWING NUMBER 842-ARVFS-701-S-3. INEL INDEX CODE NUMBER: 075 0701 60 851 151977. - Idaho National Engineering Laboratory, Advanced Reentry Vehicle Fusing System, Scoville, Butte County, ID

Tube wall thickness measurement apparatus

DOEpatents

Lagasse, P.R.

1985-06-21

An apparatus for measuring the thickness of a tube's wall for the tube's entire length and radius by determining the deviation of the tube wall thickness from the known thickness of a selected standard item. The apparatus comprises a base and a first support member having first and second ends. The first end is connected to the base and the second end is connected to a spherical element. A second support member is connected to the base and spaced apart from the first support member. A positioning element is connected to and movable relative to the second support member. An indicator is connected to the positioning element and is movable to a location proximate the spherical element. The indicator includes a contact ball for first contacting the selected standard item and holding it against the spherical element. The contact ball then contacts the tube when the tube is disposed about the spherical element. The indicator includes a dial having a rotatable needle for indicating the deviation of the tube wall thickness from the thickness of the selected standard item.

Tube wall thickness measurement apparatus

DOEpatents

Lagasse, Paul R.

1987-01-01

An apparatus for measuring the thickness of a tube's wall for the tube's entire length and circumference by determining the deviation of the tube wall thickness from the known thickness of a selected standard item. The apparatus comprises a base and a first support member having first and second ends. The first end is connected to the base and the second end is connected to a spherical element. A second support member is connected to the base and spaced apart from the first support member. A positioning element is connected to and movable relative to the second support member. An indicator is connected to the positioning element and is movable to a location proximate the spherical element. The indicator includes a contact ball for first contacting the selected standard item and holding it against the spherical element. The contact ball then contacts the tube when the tube is disposed about the spherical element. The indicator includes a dial having a rotatable needle for indicating the deviation of the tube wall thickness from the thickness of the selected standard item.

Importance of numerical analyses for determining support systems in tunneling: A comparative study from the trabzon-gumushane tunnel, Turkey

NASA Astrophysics Data System (ADS)

Kanik, Mustafa; Gurocak, Zulfu

2018-07-01

In this study, we determined the consistency of support elements from empirical rock mass classification systems, to obtain optimum support elements via comparative numerical analyses. For this purpose, the Macka tunnel, on the Trabzon-Gumushane highway and still under construction, was selected as the study area. Along the tunnel route, Late Cretaceous-aged Catak, Macka and Esiroglu Formations crop out. All the formations are cut by a Late Cretaceous Kackar Rhyodacite. Laboratory and field studies were done to determine the properties of the rock material and discontinuities. The results were used to define rock mass properties. Preliminary support systems were defined by using Rock Mass Rating (RMR), Rock Mass Quality (Q) and Rock Mass Index (RMi) systems, respectively. The suggested support elements of all classification systems were in turn evaluated using the Finite Elements Method (FEM), allowing the thickness of the plastic zone and total displacement values to be determined. Results of the analyses showed that it is possible to remove the instabilities around the tunnel section by applying lower numbers of support elements. When using the support systems from the numerical analyses it was found that the optimum support systems were compatible with the support systems suggested by the RMi system. Besides, when the shotcrete strength was increased to 40 MPa, the displacements and thickness of the plastic zone around the tunnel could be reduced to minimal values.

Bimetal catalysts

DOEpatents

Ng, K. Y. Simon; Salley, Steve O.; Wang, Huali

2017-10-03

A catalyst comprises a carbide or nitride of a metal and a promoter element. The metal is selected from the group consisting of Mo, W, Co, Fe, Rh or Mn, and the promoter element is selected from the group consisting of Ni, Co, Al, Si, S or P, provided that the metal and the promoter element are different. The catalyst also comprises a mesoporous support having a surface area of at least about 170 m.sup.2 g.sup.-1, wherein the carbide or nitride of the metal and the promoter element is supported by the mesoporous support, and is in a non-sulfided form and in an amorphous form.

METHOD OF OPERATING NUCLEAR REACTORS

DOEpatents

Untermyer, S.

1958-10-14

A method is presented for obtaining enhanced utilization of natural uranium in heavy water moderated nuclear reactors by charging the reactor with an equal number of fuel elements formed of natural uranium and of fuel elements formed of uranium depleted in U/sup 235/ to the extent that the combination will just support a chain reaction. The reactor is operated until the rate of burnup of plutonium equals its rate of production, the fuel elements are processed to recover plutonium, the depleted uranium is discarded, and the remaining uranium is formed into fuel elements. These fuel elements are charged into a reactor along with an equal number of fuel elements formed of uranium depleted in U/sup 235/ to the extent that the combination will just support a chain reaction, and reuse of the uranium is continued as aforesaid until it wlll no longer support a chain reaction when combined with an equal quantity of natural uranium.

Instrumentation for remote sensing solar radiation from light aircraft.

PubMed

Howard, J A; Barton, I J

1973-10-01

The paper outlines the instrumentation needed to study, from a light aircraft, the solar radiation reflected by ground surfaces and the incoming solar radiation. A global shortwave radiometer was mounted on the roof of the aircraft and a specially designed mount was used to support a downward pointing 70-mm aerial camera, a downward pointing narrow-beam pyranometer, and, sometimes, a downward pointing global shortwave pyranometer. Calibration factors were determined for the three pyranometers by comparison with a standard Angstrom compensation pyrheliometer. Results have indicated trends in the albedos of major plant communities and have shown that the calculated albedo values vary according to whether the downward pointing instrument is narrow-beam or global. Comparisons were also made with albedos measured on the ground.

Low-temperature synthesis of single-walled carbon nanotubes with a narrow diameter distribution using size-classified catalyst nanoparticles

NASA Astrophysics Data System (ADS)

Kondo, Daiyu; Sato, Shintaro; Awano, Yuji

2006-05-01

Single-walled carbon nanotubes (SWNTs) with a narrow diameter distribution have been synthesized by hot-filament chemical vapor deposition using acetylene at 590 °C. Iron nanoparticles with diameters of 1.6, 2.0, 2.5, 5.0 and 10 nm (standard deviation: ≈10%) obtained with a differential mobility analyzer were used as a catalyst without any supporting materials on a substrate. SWNTs were obtained from 2.0 nm or smaller particles. The ratio of G band to D band in Raman spectra was as high as 35 without purification, indicating that high-quality SWNTs were synthesized. The SWNT diameters correlated with the particle diameters, demonstrating diameter-controlled SWNT growth.

Studies of silicon p-n junction solar cells

NASA Technical Reports Server (NTRS)

Neugroschel, A.; Lindholm, F. A.

1979-01-01

To provide theoretical support for investigating different ways to obtain high open-circuit voltages in p-n junction silicon solar cells, an analytical treatment of heavily doped transparent-emitter devices is presented that includes the effects of bandgap narrowing, Fermi-Dirac statistics, a doping concentration gradient, and a finite surface recombination velocity at the emitter surface. Topics covered include: (1) experimental determination of bandgap narrowing in the emitter of silicon p-n junction devices; (2) heavily doped transparent regions in junction solar cells, diodes, and transistors; (3) high-low-emitter solar cell; (4) determination of lifetimes and recombination currents in p-n junction solar cells; (5) MOS and oxide-charged-induced BSF solar cells; and (6) design of high efficiency solar cells for space and terrestrial applications.

Static behavior of the weld in the joint of the steel support element using experiment and numerical modeling

NASA Astrophysics Data System (ADS)

Krejsa, M.; Brozovsky, J.; Mikolasek, D.; Parenica, P.; Koubova, L.

2018-04-01

The paper is focused on the numerical modeling of welded steel bearing elements using commercial software system ANSYS, which is based on the finite element method - FEM. It is important to check and compare the results of FEM analysis with the results of physical verification test, in which the real behavior of the bearing element can be observed. The results of the comparison can be used for calibration of the computational model. The article deals with the physical test of steel supporting elements, whose main purpose is obtaining of material, geometry and strength characteristics of the fillet and butt welds including heat affected zone in the basic material of welded steel bearing element. The pressure test was performed during the experiment, wherein the total load value and the corresponding deformation of the specimens under the load was monitored. Obtained data were used for the calibration of numerical models of test samples and they are necessary for further stress and strain analysis of steel supporting elements.

Static, free vibration and thermal analysis of composite plates and shells using a flat triangular shell element

NASA Astrophysics Data System (ADS)

Kapania, R. K.; Mohan, P.

1996-09-01

Finite element static, free vibration and thermal analysis of thin laminated plates and shells using a three noded triangular flat shell element is presented. The flat shell element is a combination of the Discrete Kirchhoff Theory (DKT) plate bending element and a membrane element derived from the Linear Strain Triangular (LST) element with a total of 18 degrees of freedom (3 translations and 3 rotations per node). Explicit formulations are used for the membrane, bending and membrane-bending coupling stiffness matrices and the thermal load vector. Due to a strong analogy between the induced strain caused by the thermal field and the strain induced in a structure due to an electric field the present formulation is readily applicable for the analysis of structures excited by surface bonded or embedded piezoelectric actuators. The results are presented for (i) static analysis of (a) simply supported square plates under doubly sinusoidal load and uniformly distributed load (b) simply supported spherical shells under a uniformly distributed load, (ii) free vibration analysis of (a) square cantilever plates, (b) skew cantilever plates and (c) simply supported spherical shells; (iii) Thermal deformation analysis of (a) simply supported square plates, (b) simply supported-clamped square plate and (c) simply supported spherical shells. A numerical example is also presented demonstrating the application of the present formulation to analyse a symmetrically laminated graphite/epoxy laminate excited by a layer of piezoelectric polyvinylidene flouride (PVDF). The results presented are in good agreement with those available in the literature.

Improved particle impactor assembly for size selective high volume air sampler

DOEpatents

Langer, G.

1987-03-23

Air containing entrained particulate matter is directed through a plurality of parallel, narrow, vertically oriented apertures of an inlet element toward an adjacently located, relatively large, dust impaction surface preferably covered with an adhesive material. The air flow turns over the impaction surface, leaving behind, the relatively larger particles and passes through two elongate apertures defining the outer bounds of the impaction collection surface to pass through divergent passages which slow down and distribute the air flow, with entrained smaller particles, over a fine filter element that separates the fine particles from the air. By appropriate selection of dimensions and the number of inlet apertures air flow through the inlet element is provided a nonuniform velocity distribution with the lower velocities being obtained near the center of the inlet apertures, to separate out particles larger than a certain predetermined size on the impaction collection surface. The impaction collection surface, even in a moderately sized apparatus, is thus relatively large and permits the prolonged sampling of air for periods extending to four weeks. 6 figs.

The effect of embodied emotive states on cognitive categorization.

PubMed

Price, Tom F; Harmon-Jones, Eddie

2010-12-01

Research has uncovered that positive affect broadens cognitive categorization. The motivational dimensional model, however, posits that positive affect is not a unitary construct with only one cognitive consequence. Instead, this model puts forth that there are different positive affects varying in approach motivational intensity. According to this model, only positive affects lower in motivational intensity should broaden cognitive processes, whereas positive affects higher in motivational intensity should narrow cognitive processes. Consistent with these predictions, high approach positive affect has been shown to narrow attention, whereas low approach positive affect has been shown to broaden it (Gable & Harmon-Jones, 2008). High approach positive affect, therefore, might narrow categorization. Two experiments investigated this possibility by having participants respond to cognitive categorization tasks in 3 body postures designed to elicit different levels of approach motivation: reclining backward, which should evoke low approach motivation; sitting upright, which should evoke moderate approach motivation; and leaning forward, which should evoke high approach motivation. Participants smiled while in each posture in order to experience positive affect. Experiment 1 provided initial support for the idea that high approach positive affect narrows categorization and low approach positive affect broadens categorization. Experiment 2 replicated these findings with improved smiling instructions. These results extend previous work by showing that the motivational model's predictions hold for basic attentional processes as well as higher level cognitive processes such as categorization.

"I thought this course was going to be streamlined!": the limits of normal and the possibilities of transgression.

PubMed

Simpson, Jennifer S

2012-01-01

This article offers an analysis of the parallels between neo-liberalism, epistemology, and pedagogy, specifically related to how neoliberal ideologies narrow the possibilities for considering transgressive sexualities. Lesbian, gay, bisexual, transgender, and queer (LGBTQ) education encourages educators to consider queer lives and communities, and can do so in ways that leave intact or challenge dominant norms. Neoliberalism, an economic expression of liberalism, rests on ideologies that support privatization and a diminished notion of the public good. These ideologies can become intertwined with epistemological expectations in the classroom. Related to queer theory and pedagogy, neoliberalism can profoundly narrow the possibilities for queer subjecthood. Epistemological neoliberalism, or structures of knowing that endorse an often falsely rendered normality, can be active in the classroom. This article explores two comments students offered in courses on gender and communication to explore the ways in which neoliberal ideologies bear on epistemological and pedagogical practices in ways that profoundly narrow conceptions of the social and constitutions of the subject, particularly related to transgressive sexualities and queer lives.

QSO Narrow [OIII] Line Width and Host Galaxy Luminosity

NASA Astrophysics Data System (ADS)

Bonning, E. W.; Shields, G. A.; Salviander, S.

2004-05-01

Established correlations between galaxy bulge luminosity L, black hole mass MBH, and stellar velocity dispersion sigma in galaxies suggest a close relationship between the growth of supermassive black holes and their host galaxies. Measurements of the MBH - sigma relationship as a function of cosmic time may shed light on the origin of this relationship. One approach is to derive MBH and sigma from the widths of QSO broad and narrow lines, respectively (Shields et al. 2003, ApJ, 583, 124; Nelson 2000, ApJ, 544, L91). We investigate the utility of using the velocity of the narrow line emitting gas as a surrogate for stellar velocity dispersion in QSOs by examining host magnitudes and [OIII] line widths for low redshift QSOs. For our limited range of L, the increase in sigma with L predicted by the Faber-Jackson relation is substantially obscured by scatter. However, sigma([O III]) is consistent in the mean with host galaxy luminosity. EWB is a NASA GSRP fellow. GAS and SS are supported under Texas Advanced Research Program grant 003658-0177-2001 and NSF grant AST-0098594.

Rapid trench initiated recrystallization and stagnation in narrow Cu interconnect lines

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

O'Brien, Brendan B.; Rizzolo, Michael; Prestowitz, Luke C.

2015-10-26

Understanding and ultimately controlling the self-annealing of Cu in narrow interconnect lines has remained a top priority in order to continue down-scaling of back-end of the line interconnects. Recently, it was hypothesized that a bottom-up microstructural transformation process in narrow interconnect features competes with the surface-initiated overburden transformation. Here, a set of transmission electron microscopy images which captures the grain coarsening process in 48 nm lines in a time resolved manner is presented, supporting such a process. Grain size measurements taken from these images have demonstrated that the Cu microstructural transformation in 48 nm interconnect lines stagnates after only 1.5 h atmore » room temperature. This stubborn metastable structure remains stagnant, even after aggressive elevated temperature anneals, suggesting that a limited internal energy source such as dislocation content is driving the transformation. As indicated by the extremely low defect density found in 48 nm trenches, a rapid recrystallization process driven by annihilation of defects in the trenches appears to give way to a metastable microstructure in the trenches.« less

77 FR 32598 - 36(b)(1) Arms Sales Notification

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-01

... engineering and logistics support services, and other related elements of logistics support. (iv) Military.... Government and contractor engineering and logistics support services, and other related elements of logistics... acceptable military balance in the area. The Republic of Korea (ROK) intends to use the HARPOON Block II...

Laser apparatus

DOEpatents

Lewis, Owen; Stogran, Edmund M.

1980-01-01

Laser apparatus is described wherein an active laser element, such as the disc of a face-pumped laser, is mounted in a housing such that the weight of the element is supported by glass spheres which fill a chamber defined in the housing between the walls of the housing and the edges of the laser element. The uniform support provided by the spheres enable the chamber and the pump side of the laser element to be sealed without affecting the alignment or other optical properties of the laser element. Cooling fluid may be circulated through the sealed region by way of the interstices between the spheres. The spheres, and if desired also the cooling fluid may contain material which absorbs radiation at the wavelength of parasitic emissions from the laser element. These parasitic emissions enter the spheres through the interface along the edge surface of the laser element and it is desirable that the index of refraction of the spheres and cooling fluid be near the index of refraction of the laser element. Thus support, cooling, and parasitic suppression functions are all accomplished through the use of the arrangement.

Fabrication Method for LOBSTER-Eye Optics in <110> Silicon

NASA Technical Reports Server (NTRS)

Chervenak, James; Collier, Michael; Mateo, Jennette

2013-01-01

Soft x-ray optics can use narrow slots to direct x-rays into a desirable pattern on a focal plane. While square-pack, square-pore, slumped optics exist for this purpose, they are costly. Silicon (Si) is being examined as a possible low-cost replacement. A fabrication method was developed for narrow slots in <110> Si demonstrating the feasibility of stacked slot optics to replace micropores. Current micropore optics exist that have 20-micron-square pores on 26-micron pitch in glass with a depth of 1 mm and an extent of several square centimeters. Among several proposals to emulate the square pore optics are stacked slot chips with etched vertical slots. When the slots in the stack are positioned orthogonally to each other, the component will approach the soft x-ray focusing observed in the micropore optics. A specific improvement Si provides is that it can have narrower sidewalls between slots to permit greater throughput of x-rays through the optics. In general, Si can have more variation in slot geometry (width, length). Further, the sidewalls can be coated with high-Z materials to enhance reflection and potentially reduce the surface roughness of the reflecting surface. Narrow, close-packed deep slots in <110> Si have been produced using potassium hydroxide (KOH) etching and a patterned silicon nitride (SiN) mask. The achieved slot geometries have sufficient wall smoothness, as observed through scanning electron microscope (SEM) imaging, to enable evaluation of these slot plates as an optical element for soft x-rays. Etches of different angles to the crystal plane of Si were evaluated to identify a specific range of etch angles that will enable low undercut slots in the Si <110> material. These slots with the narrow sidewalls are demonstrated to several hundred microns in depth, and a technical path to 500-micron deep slots in a precision geometry of narrow, closepacked slots is feasible. Although intrinsic stress in ultrathin wall Si is observed, slots with walls approaching 1.5 microns can be achieved (a significant improvement over the 6-micron walls in micro - pore optics). The major advantages of this technique are the potential for higher x-ray throughout (due to narrow slot walls) and lower cost over the existing slumped micropore glass plates. KOH etching of smooth sidewalls has been demonstrated for many applications, suggesting its feasibility for implementation in x-ray optics. Si cannot be slumped like the micropore optics, so the focusing will be achieved with millimeter-scale slot plates that populate a spherical dome. The possibility for large-scale production exists for Si parts that is more difficult to achieve in micropore parts.

Cranial architecture of tube-snouted gasterosteiformes (Syngnathus rostellatus and Hippocampus capensis).

PubMed

Leysen, Heleen; Jouk, Philippe; Brunain, Marleen; Christiaens, Joachim; Adriaens, Dominique

2010-03-01

The long snout of pipefishes and seahorses (Syngnathidae, Gasterosteiformes) is formed as an elongation of the ethmoid region. This is in contrast to many other teleosts with elongate snouts (e.g., butterflyfishes) in which the snout is formed as an extension of the jaws. Syngnathid fishes perform very fast suction feeding, accomplished by powerful neurocranial elevation and hyoid retraction. Clearly, suction through a long and narrow tube and its hydrodynamic implications can be expected to require certain adaptations in the cranium, especially in musculoskeletal elements of the feeding apparatus. Not much is known about which skeletal elements actually support the snout and what the effect of elongation is on related structures. Here, we give a detailed morphological description of the cartilaginous and bony feeding apparatus in both juvenile and adult Syngnathus rostellatus and Hippocampus capensis. Our results are compared with previous morphological studies of a generalized teleost, Gasterosteus aculeatus. We found that the ethmoid region is elongated early during development, with the ethmoid plate, the hyosymplectic, and the basihyal cartilage being extended in the chondrocranium. In the juveniles of both species almost all bones are forming, although only as a very thin layer. The elongation of the vomeral, mesethmoid, quadrate, metapterygoid, symplectic, and preopercular bones is already present. Probably, because of the long and specialized parental care which releases advanced developmental stages from the brooding pouch, morphology of the feeding apparatus of juveniles is already very similar to that of the adults. We describe morphological features related to snout elongation that may be considered adaptations for suction feeding; e.g. the peculiar shape of the interhyal bone and its saddle-shaped articulation with the posterior ceratohyal bone might aid in explosive hyoid retraction by reducing the risk of hyoid dislocation.

Formation of fast-spreading lower oceanic crust as revealed by a new Mg-REE coupled geospeedometer

NASA Astrophysics Data System (ADS)

Sun, Chenguang; Lissenberg, C. Johan

2018-04-01

A new geospeedometer is developed based on the differential closures of Mg and rare earth element (REE) bulk-diffusion between coexisting plagioclase and clinopyroxene. By coupling the two elements with distinct bulk closure temperatures, this speedometer can numerically solve the initial temperatures and cooling rates for individual rock samples. As the existing Mg-exchange thermometer was calibrated for a narrow temperature range and strongly relies on model-dependent silica activities, a new thermometer is developed using literature experimental data. When the bulk closure temperatures of Mg and REE are determined, respectively, using this new Mg-exchange thermometer and the existing REE-exchange thermometer, this speedometer can be implemented for a wide range of compositions, mineral modes, and grain sizes. Applications of this new geospeedometer to oceanic gabbros from the fast-spreading East Pacific Rise at Hess Deep reveal that the lower oceanic crust crystallized at temperatures of 998-1353 °C with cooling rates of 0.003-10.2 °C/yr. Stratigraphic variations of the cooling rates and crystallization temperatures support deep hydrothermal circulations and in situ solidification of various replenished magma bodies. Together with existing petrological, geochemical and geophysical evidence, results from this new speedometry suggest that the lower crust formation at fast-spreading mid-ocean ridges involves emplacement of primary mantle melts in the deep section of the crystal mush zone coupled with efficient heat removal by crustal-scale hydrothermal circulations. The replenished melts become chemically and thermally evolved, accumulate as small magma bodies at various depths, feed the shallow axial magma chamber, and may also escape from the mush zone to generate off-axial magma lenses.

Experimental Study of Slat Noise from 30P30N Three-Element High-Lift Airfoil in JAXA Hard-Wall Low-Speed Wind Tunnel

NASA Technical Reports Server (NTRS)

Murayama, Mitsuhiro; Nakakita, Kazuyuki; Yamamoto, Kazuomi; Ura, Hiroki; Ito, Yasushi; Choudhari, Meelan M.

2014-01-01

Aeroacoustic measurements associated with noise radiation from the leading edge slat of the canonical, unswept 30P30N three-element high-lift airfoil configuration have been obtained in a 2 m x 2 m hard-wall wind tunnel at the Japan Aerospace Exploration Agency (JAXA). Performed as part of a collaborative effort on airframe noise between JAXA and the National Aeronautics and Space Administration (NASA), the model geometry and majority of instrumentation details are identical to a NASA model with the exception of a larger span. For an angle of attack up to 10 degrees, the mean surface Cp distributions agree well with free-air computational fluid dynamics predictions corresponding to a corrected angle of attack. After employing suitable acoustic treatment for the brackets and end-wall effects, an approximately 2D noise source map is obtained from microphone array measurements, thus supporting the feasibility of generating a measurement database that can be used for comparison with free-air numerical simulations. Both surface pressure spectra obtained via KuliteTM transducers and the acoustic spectra derived from microphone array measurements display a mixture of a broad band component and narrow-band peaks (NBPs), both of which are most intense at the lower angles of attack and become progressively weaker as the angle of attack is increased. The NBPs exhibit a substantially higher spanwise coherence in comparison to the broadband portion of the spectrum and, hence, confirm the trends observed in previous numerical simulations. Somewhat surprisingly, measurements show that the presence of trip dots between the stagnation point and slat cusp enhances the NBP levels rather than mitigating them as found in a previous experiment.

Crystal structure of the mobile metallo-β-lactamase AIM-1 from Pseudomonas aeruginosa: insights into antibiotic binding and the role of Gln157.

PubMed

Leiros, Hanna-Kirsti S; Borra, Pardha S; Brandsdal, Bjørn Olav; Edvardsen, Kine Susann Waade; Spencer, James; Walsh, Timothy R; Samuelsen, Orjan

2012-08-01

Metallo-β-lactamase (MBL) genes confer resistance to virtually all β-lactam antibiotics and are rapidly disseminated by mobile genetic elements in Gram-negative bacteria. MBLs belong to three different subgroups, B1, B2, and B3, with the mobile MBLs largely confined to subgroup B1. The B3 MBLs are a divergent subgroup of predominantly chromosomally encoded enzymes. AIM-1 (Adelaide IMipenmase 1) from Pseudomonas aeruginosa was the first B3 MBL to be identified on a readily mobile genetic element. Here we present the crystal structure of AIM-1 and use in silico docking and quantum mechanics and molecular mechanics (QM/MM) calculations, together with site-directed mutagenesis, to investigate its interaction with β-lactams. AIM-1 adopts the characteristic αβ/βα sandwich fold of MBLs but differs from other B3 enzymes in the conformation of an active site loop (residues 156 to 162) which is involved both in disulfide bond formation and, we suggest, interaction with substrates. The structure, together with docking and QM/MM calculations, indicates that the AIM-1 substrate binding site is narrower and more restricted than those of other B3 MBLs, possibly explaining its higher catalytic efficiency. The location of Gln157 adjacent to the AIM-1 zinc center suggests a role in drug binding that is supported by our in silico studies. However, replacement of this residue by either Asn or Ala resulted in only modest reductions in AIM-1 activity against the majority of β-lactam substrates, indicating that this function is nonessential. Our study reveals AIM-1 to be a subclass B3 MBL with novel structural and mechanistic features.

Crystal Structure of the Mobile Metallo-β-Lactamase AIM-1 from Pseudomonas aeruginosa: Insights into Antibiotic Binding and the Role of Gln157

PubMed Central

Borra, Pardha S.; Brandsdal, Bjørn Olav; Edvardsen, Kine Susann Waade; Spencer, James; Walsh, Timothy R.; Samuelsen, Ørjan

2012-01-01

Metallo-β-lactamase (MBL) genes confer resistance to virtually all β-lactam antibiotics and are rapidly disseminated by mobile genetic elements in Gram-negative bacteria. MBLs belong to three different subgroups, B1, B2, and B3, with the mobile MBLs largely confined to subgroup B1. The B3 MBLs are a divergent subgroup of predominantly chromosomally encoded enzymes. AIM-1 (Adelaide IMipenmase 1) from Pseudomonas aeruginosa was the first B3 MBL to be identified on a readily mobile genetic element. Here we present the crystal structure of AIM-1 and use in silico docking and quantum mechanics and molecular mechanics (QM/MM) calculations, together with site-directed mutagenesis, to investigate its interaction with β-lactams. AIM-1 adopts the characteristic αβ/βα sandwich fold of MBLs but differs from other B3 enzymes in the conformation of an active site loop (residues 156 to 162) which is involved both in disulfide bond formation and, we suggest, interaction with substrates. The structure, together with docking and QM/MM calculations, indicates that the AIM-1 substrate binding site is narrower and more restricted than those of other B3 MBLs, possibly explaining its higher catalytic efficiency. The location of Gln157 adjacent to the AIM-1 zinc center suggests a role in drug binding that is supported by our in silico studies. However, replacement of this residue by either Asn or Ala resulted in only modest reductions in AIM-1 activity against the majority of β-lactam substrates, indicating that this function is nonessential. Our study reveals AIM-1 to be a subclass B3 MBL with novel structural and mechanistic features. PMID:22664968

The relationship between the availability of the supporting elements of pedestrian with pedestrian crossing facility usage based on user preferences (Case Study corridor of Sumbersari Street, Gajayana Street, MT. Haryono Street, Malang City)

NASA Astrophysics Data System (ADS)

Soetrisno, D. P.

2017-06-01

Pedestrian crossing facilities are effective enough to avoid pedestrians with vehicles, but its utilization is still quite low. It indicated that safety is not the only factor that influences a person to utilize the pedestrian crossing facilities. In addition, the availability of supporting elements of the pedestrian is still not quite attention, which is also became a factor that causes the pedestrians doesn’t utilize the pedestrian crossing facilities. Therefore, this research was structured to examine the relationship between the availability of the supporting elements of the pedestrian with pedestrian crossing facility usage based on user preferences. Data collection method used is primary survey consist of observation and the questionnaire. Sampling techniques used is purposive sampling with the number of respondents as many as 211 respondents by using questionnaire with ordinal scales to identify respondents’ consideration level of supporting elements pedestrian and crossing facility utilization factors. The survey is done on 15 crossing facilities area in 3 different locations with the same characteristics of land use in the form of higher education area (university area) and trades and services activities area. The analysis technique used is frequency distribution analysis in order to identify preference pedestrian on the availability of supporting elements of pedestrian and pedestrian crossing facility utilization factors, and chi square analysis is used to analyze the relationship between the availability of the supporting elements of the pedestrian with pedestrian crossing facility utilization. Based on the chi square analysis results with significance 5 % obtained the result that there are six supporting elements of pedestrian having correlation to the factors of pedestrian crossing facility utilization consist of the availability of sidewalk, pedestrian lights, Street Lighting Lamps, Pedestrian Crossing Markings Facilities, Sign Crossings Facilities, vegetation, and dustbin. So the result of this research can be considered for the government as main stakehoder especially the local government in preparing policy to provide supporting elements of pedestrian that should be on the area of pedestrian crossing facilities.

Shear Stress induced Stretching of Red Blood Cells by Oscillating Bubbles within a Narrow Gap

NASA Astrophysics Data System (ADS)

Li, Fenfang; Mohammadzadeh, Milad; Ohl, Claus-Dieter; Claus-Dieter Ohl Team

2013-11-01

The flow pattern, especially the boundary layer caused by the expanding/contracting bubble in a narrow gap (15 μm) and the resultant stretching of red blood cells is investigated in this work. High speed recordings show that a red blood cell (biconcave shape, thickness of 1-2 μm) can be elongated to five times its original length by a laser-induced cavitation bubble within the narrow gap. However, flexible cancer cells in suspension (RKO, spherical shape, diameter of 10-15 μm) are hardly elongated under the same experimental condition. We hypothesize that the shear stress at the boundary layer is crucial for this elongation to occur. Therefore, in order to resolve the related fluid dynamics, we conducted numerical simulations using the finite element method (Fluent). The rapidly expanding/contracting vapor bubble is successfully modeled by employing viscosity and surface tension. The transient pressure inside the bubble and the velocity profile of the flow is obtained. We observe strong shear near the upper and lower boundary during the bubble oscillation. The flow fields are compared with analytical solutions to transient and pulsating flows in 2D. In the experiment the red blood cells sit within the lower boundary layer, thus are probably elongated by this strong shear flow. In contrast, the spherical cancer cells are of comparable size to the gap height so that they are lesser affected by this boundary layer flow.

Hormone purification by isoelectric focusing in space

NASA Technical Reports Server (NTRS)

Bier, M.

1988-01-01

The objective of the program was the definition and development of optimal methods for electrophoretic separations in microgravity. The approach is based on a triad consisting of ground based experiments, mathematical modeling and experiments in microgravity. Zone electrophoresis is a rate process, where separation is achieved in uniform buffers on the basis of differences in electrophoretic mobilities. Optimization and modeling of continuous flow electrophoresis mainly concern the hydrodynamics of the flow process, including gravity dependent fluid convection due to density gradients and gravity independent electroosmosis. Optimization of focusing requires a more complex model describing the molecular transport processes involved in electrophoresis of interacting systems. Three different focusing instruments were designed, embodying novel principles of fluid stabilization. Fluid stability was achieved by: (1) flow streamlining by means of membrane elements in combination with rapid fluid recycling; (2) apparatus rotation in combination with said membrane elements; and (3) shear stress induced by rapid recycling through a narrow gap channel.

Anti-Hermitian photodetector facilitating efficient subwavelength photon sorting.

PubMed

Kim, Soo Jin; Kang, Ju-Hyung; Mutlu, Mehmet; Park, Joonsuk; Park, Woosung; Goodson, Kenneth E; Sinclair, Robert; Fan, Shanhui; Kik, Pieter G; Brongersma, Mark L

2018-01-22

The ability to split an incident light beam into separate wavelength bands is central to a diverse set of optical applications, including imaging, biosensing, communication, photocatalysis, and photovoltaics. Entirely new opportunities are currently emerging with the recently demonstrated possibility to spectrally split light at a subwavelength scale with optical antennas. Unfortunately, such small structures offer limited spectral control and are hard to exploit in optoelectronic devices. Here, we overcome both challenges and demonstrate how within a single-layer metafilm one can laterally sort photons of different wavelengths below the free-space diffraction limit and extract a useful photocurrent. This chipscale demonstration of anti-Hermitian coupling between resonant photodetector elements also facilitates near-unity photon-sorting efficiencies, near-unity absorption, and a narrow spectral response (∼ 30 nm) for the different wavelength channels. This work opens up entirely new design paradigms for image sensors and energy harvesting systems in which the active elements both sort and detect photons.

Temporal behavior of RHEED intensity oscillations during molecular beam epitaxial growth of GaAs and AlGaAs on (111)B GaAs substrates

NASA Astrophysics Data System (ADS)

Yen, Ming Y.; Haas, T. W.

1990-10-01

We present the temporal behavior of intensity oscillations in reflection high-energy electron diffraction (RHEED) during molecular beam epitaxial (MBE) growth of GaAs and A1GaAs on (1 1 1)B GaAs substrates. The RHEED intensity oscillations were examined as a function of growth parameters in order to provide the insight into the dynamic characteristics and to identify the optimal condition for the two-dimensional layer-by-layer growth. The most intense RHEED oscillation was found to occur within a very narrow temperature range which seems to optimize the surface migration kinetics of the arriving group III elements and the molecular dissodiative reaction of the group V elements. The appearance of an initial transient of the intensity upon commencement of the growth and its implications are described.

On sound transmission into a stiffened cylindrical shell with rings and stringers treated as discrete elements

NASA Technical Reports Server (NTRS)

Koval, L. R.

1980-01-01

In the context of the transmission of airborne noise into an aircraft fuselage, a mathematical model is presented for the transmission of an oblique plane sound wave into a finite cylindrical shell stiffened by stringers and ring frames. The rings and stringers are modeled as discrete structural elements. The numerical case studied was typical of a narrow-bodied jet transport fuselage. The numerical results show that the ring-frequency dip in the transmission loss curve that is present for a monocoque shell is still present in the case of a stiffened shell. The ring frequency effect is a result of the cylindrical geometry of the shell. Below the ring frequency, stiffening does not appear to have any significant effect on transmission loss, but above the ring frequency, stiffeners can enhance the transmission loss of a cylindrical shell.

4D Printed Actuators with Soft-Robotic Functions.

PubMed

López-Valdeolivas, María; Liu, Danqing; Broer, Dick Jan; Sánchez-Somolinos, Carlos

2018-03-01

Soft matter elements undergoing programed, reversible shape change can contribute to fundamental advance in areas such as optics, medicine, microfluidics, and robotics. Crosslinked liquid crystalline polymers have demonstrated huge potential to implement soft responsive elements; however, the complexity and size of the actuators are limited by the current dominant thin-film geometry processing toolbox. Using 3D printing, stimuli-responsive liquid crystalline elastomeric structures are created here. The printing process prescribes a reversible shape-morphing behavior, offering a new paradigm for active polymer system preparation. The additive character of this technology also leads to unprecedented geometries, complex functions, and sizes beyond those of typical thin-films. The fundamental concepts and devices presented therefore overcome the current limitations of actuation energy available from thin-films, thereby narrowing the gap between materials and practical applications. © 2017 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Vertical velocity structure and geometry of clear air convective elements

NASA Technical Reports Server (NTRS)

Rowland, J. R.; Arnold, A.

1975-01-01

The paper discusses observations of individual convective elements with a high-power narrow-beam scanning radar, an FM-CW radar, and an acoustic sounder, including the determination of the vertical air velocity patterns of convective structures with the FM-CW radar and acoustic sounder. Data are presented which link the observed velocity structure and geometrical patterns to previously proposed models of boundary layer convection. It is shown that the high-power radar provides a clear three-dimensional picture of convective cells and fields over a large area with a resolution of 150 m, where the convective cells are roughly spherical. Analysis of time-height records of the FM-CW radar and acoustic sounder confirms the downdraft-entrainment mechanism of the convective cell. The Doppler return of the acoustic sounder and the insect-trail slopes on FM-CW radar records are independent but redundant methods for obtaining the vertical velocity patterns of convective structures.

Effect of periodic fluctuation of soil particle rotation resistance on interface shear behaviour

NASA Astrophysics Data System (ADS)

Ebrahimian, Babak; Noorzad, Asadollah

2010-06-01

The interface behaviour between infinite extended narrow granular layer and bounding structure is numerically investigated using finite element method. The micro-polar (Cosserat) continuum approach within the framework of elasto-plasticity is employed to remove the numerical difficulties caused by strain-softening of materials in classical continuum mechanics. Mechanical properties of cohesionless granular soil are described with Lade's model enhanced with polar terms including Cosserat rotations, curvatures and couple stresses via mean grain diameter as the internal length. The main attention of paper is laid on the influence of spatial periodic fluctuation of rotation resistance of soil particles interlocked with the surface of bounding structure on evolution and location of shear band developed inside granular body. The finite element results demonstrate that the location and evolution of shear localization in granular body is strongly affected by prescribed non-uniform micro-polar kinematic boundary conditions along the interface.

Sources of anthropogenic platinum-group elements (PGE): Automotive catalysts versus PGE-processing industries.

PubMed

Zereini, F; Dirksen, F; Skerstupp, B; Urban, H

1998-01-01

Soil samples from the area of Hanau (Hessen, Germany) were analyzed for anthropogenic platinum-group elements (PGE). The results confirm the existence of two different sources for anthropogenic PGE: 1. automotive catalysts, and 2. PGE-processing plants. Both sources emit qualitatively and quantitatively different PGE spectra and PGE interelemental ratios (especially the Pt/Rh ratio). Elevated PGE values which are due to automotive catalysts are restricted to a narrow-range along roadside soil, whereas those due to PGE-processing plants display a large-area dispersion. The emitted PGE-containing particles in the case of automotive catalysts are subject to transport by wind and water, whereas those from PGE-processing plants are preferably transported by wind. This points to a different aerodynamic particle size. Pt, Pd, and Rh concentrations along motorways are dependent on the amount of traffic and the driving characteristics.

The Automated Logistics Element Planning System (ALEPS)

NASA Technical Reports Server (NTRS)

Schwaab, Douglas G.

1991-01-01

The design and functions of ALEPS (Automated Logistics Element Planning System) is a computer system that will automate planning and decision support for Space Station Freedom Logistical Elements (LEs) resupply and return operations. ALEPS provides data management, planning, analysis, monitoring, interfacing, and flight certification for support of LE flight load planning activities. The prototype ALEPS algorithm development is described.

Talk to Me, Baby! How You Can Support Young Children's Language Development

ERIC Educational Resources Information Center

Bardige, Betty S.

2009-01-01

Playful, engaging talk with young children is much more than a social activity: it's the foundation of language, intellectual, and social-emotional development, and it's also the key to narrowing the achievement gap between children from different socioeconomic backgrounds. Now there's a practical, easy-to-read guidebook that shows professionals…

Personalized Surgical Risk Assessment Using Population-Based Data Analysis

ERIC Educational Resources Information Center

AbuSalah, Ahmad Mohammad

2013-01-01

The volume of information generated by healthcare providers is growing at a relatively high speed. This tremendous growth has created a gap between knowledge and clinical practice that experts say could be narrowed with the proper use of healthcare data to guide clinical decisions and tools that support rapid information availability at the…

Regression Discontinuity and Beyond: Options for Studying External Validity in an Internally Valid Design

ERIC Educational Resources Information Center

Wing, Coady; Bello-Gomez, Ricardo A.

2018-01-01

Treatment effect estimates from a "regression discontinuity design" (RDD) have high internal validity. However, the arguments that support the design apply to a subpopulation that is narrower and usually different from the population of substantive interest in evaluation research. The disconnect between RDD population and the…

Roadblocks to Integrating Technology into Classroom Instruction

ERIC Educational Resources Information Center

Knight, Courteney Lester

2012-01-01

Although research has concluded that technology can enhance the teaching and learning processes, teachers have not yet fully adopted technology to support their teaching methodologies. In the last decade or so, as the accessible gap narrowed, the focus switched to other factors. This study attempts to answer the question: Why teachers do not fully…

Locating Object Knowledge in the Brain: Comment on Bowers's (2009) Attempt to Revive the Grandmother Cell Hypothesis

ERIC Educational Resources Information Center

Plaut, David C.; McClelland, James L.

2010-01-01

According to Bowers, the finding that there are neurons with highly selective responses to familiar stimuli supports theories positing localist representations over approaches positing the type of distributed representations typically found in parallel distributed processing (PDP) models. However, his conclusions derive from an overly narrow view…

Ontology-Based Peer Exchange Network (OPEN)

ERIC Educational Resources Information Center

Dong, Hui

2010-01-01

In current Peer-to-Peer networks, distributed and semantic free indexing is widely used by systems adopting "Distributed Hash Table" ("DHT") mechanisms. Although such systems typically solve a. user query rather fast in a deterministic way, they only support a very narrow search scheme, namely the exact hash key match. Furthermore, DHT systems put…

Educational Decentralization, Public Spending, and Social Justice in Nigeria

ERIC Educational Resources Information Center

Geo-Jaja, Macleans A.

2006-01-01

This study situates the process of educational decentralization in the narrower context of social justice. Its main object, however, is to analyze the implications of decentralization for strategies of equity and social justice in Nigeria. It starts from the premise that the early optimism that supported decentralization as an efficient and…

Challenges Faced by Faculty Who Transition to Post-Secondary Online Education

ERIC Educational Resources Information Center

Chester, Maryanne Christine

2012-01-01

Online education has provided the opportunity for many learners to pursue higher education. However, training is crucial for instructors who may be hesitant to transition to online teaching, unaware of online teaching strategies, and lack support from educational institutions. The purpose of this qualitative case study was to narrow the knowledge…

Pack Factor Measurementss for Corn in Grain Storage Bins

USDA-ARS?s Scientific Manuscript database

Grain is commonly stored commercially in tall bins, which often are as deep as 35 m (114.8 ft) for tall and narrow concrete bins and about 32 m (105 ft) in diameter for large corrugated steel bins. Grain can support the great pressure without crushing, but it yields somewhat to compaction under its ...

Transforming Supervision: Using Video Elicitation to Support Preservice Teacher-Directed Reflective Conversations

ERIC Educational Resources Information Center

Sewall, Marcia

2009-01-01

Since constraints on time, resources, and even energy often come into play in finding opportunities for meaningful discussions about pedagogy between the novice teacher (NT) and the supervisor, post-lesson conversations at the school site can often be brief, superficial, lacking reflective self-analysis, narrow in focus, interrupted, or even…

Supporting Oral Narrative Development of Kindergarten English Language Learners Using Multimedia Stories

ERIC Educational Resources Information Center

Yang, Sha

2016-01-01

Narrative ability comes before literacy for bilingual students and helps narrow down the gap in text-level literacy between English language learners (ELLs) and native English speakers. Kindergarten ELLs are the best age group to receive intervention to improve their oral narrative skills. Multimedia stories have potential to assist kindergarten…

Revisiting Reform in North Carolina: Responding to "First in America"--An Open Letter to Former Governor James B. Hunt, Jr.

ERIC Educational Resources Information Center

Gabbard, David A.; L'Esperance, Mark

2002-01-01

Makes the case that the narrow approach to accountability mandated in North Carolina hinders the realization of the governor's plan for education reform. States that school cultures shaped by a testing environment do not support what is recognized as good teaching. (SK)

75 FR 79035 - Nationally Recognized Testing Laboratories; Supplier's Declaration of Conformity

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-17

... statistic, however, covers only a narrow subset of ICT equipment, and excludes laptop computers and computer... between 2003 and March of 2009 shows a total of 60 product recalls, including laptop computers, scanners..., statistical or similar data and studies, of a credible nature, supporting any claims made by commenters.'' (73...

Contemporary Public Policy Influencing Children and Families: "Compassionate" Social Provision or the Regulation of "Others"?

ERIC Educational Resources Information Center

Cannella, Gaile S.; Swadener, Beth Blue

2006-01-01

Critical analysis of change in public policy within and across nations recognizes that the education and welfare of children, families, and all citizens is intertwined with economics, politics, and cultural discourse(s). In the United States, increasingly narrow media, judiciary, and academic discourses have supported legislative actions that…

Observations of GAIA-identified Cataclysmic Variables Using the TUBITAK National Observatory

NASA Astrophysics Data System (ADS)

Esenoglu, Hasan H.; Kirbiyik, Halil; Kaynar, Suleyman; Okuyan, Oguzhan; Hamitoglu, Irek; Galeev, Almaz; Uluc, Kadir; Kocak, Murat; Kilic, Sila E.; Parmaksizoglu, Murat; Erece, Orhan; Ozisik, Tuncay; Gulsecen, Hulusi

2016-07-01

TUBITAK National Observatory supports the GAIA alerts with observations using three telescopes (RTT150, T100, T60) at the site with a limited time quota. We have observed 10 variable stars among GAIA sources discovered in the years 2014-2016 that may be candidate Cataclysmic Variables (CVs). Our TUG observations at this stage involve photometry and spectroscopy to aid the identification of these sources. The first preliminary result of our observations of Gaia14aat among them showed a dwarf nova outburst with an amplitude of 2.69 mag. We aim to construct a GAIA astrophysics group to study CVs along with supported studies using the SRG (Spectrum Roentgen Gamma astrophysical observatory) after the year of 2016. These observations will basically involve spectroscopy, narrow-band CCD imaging and photometry using several filters to aid the identification of these sources. RTT150 observations with very narrow filters (like H-alpha, SII, OIII with band width of range of 2 to 5 nm) will reveal whether shell around the SRG sources to aid identification novae among them.

Voyager spacecraft images of Jupiter and Saturn

NASA Technical Reports Server (NTRS)

Birnbaum, M. M.

1982-01-01

The Voyager imaging system is described, noting that it is made up of a narrow-angle and a wide-angle TV camera, each in turn consisting of optics, a filter wheel and shutter assembly, a vidicon tube, and an electronics subsystem. The narrow-angle camera has a focal length of 1500 mm; its field of view is 0.42 deg and its focal ratio is f/8.5. For the wide-angle camera, the focal length is 200 mm, the field of view 3.2 deg, and the focal ratio of f/3.5. Images are exposed by each camera through one of eight filters in the filter wheel on the photoconductive surface of a magnetically focused and deflected vidicon having a diameter of 25 mm. The vidicon storage surface (target) is a selenium-sulfur film having an active area of 11.14 x 11.14 mm; it holds a frame consisting of 800 lines with 800 picture elements per line. Pictures of Jupiter, Saturn, and their moons are presented, with short descriptions given of the area being viewed.

Integration of narrow-host-range vectors from Escherichia coli into the genomes of amino acid-producing corynebacteria after intergeneric conjugation.

PubMed

Mateos, L M; Schäfer, A; Kalinowski, J; Martin, J F; Pühler, A

1996-10-01

Conjugative transfer of mobilizable derivatives of the Escherichia coli narrow-host-range plasmids pBR322, pBR325, pACYC177, and pACYC184 from E. coli to species of the gram-positive genera Corynebacterium and Brevibacterium resulted in the integration of the plasmids into the genomes of the recipient bacteria. Transconjugants appeared at low frequencies and reproducibly with a delay of 2 to 3 days compared with matings with replicative vectors. Southern analysis of corynebacterial transconjugants and nucleotide sequences from insertion sites revealed that integration occurs at different locations and that different parts of the vector are involved in the process. Integration is not dependent on indigenous insertion sequence elements but results from recombination between very short homologous DNA segments (8 to 12 bp) present in the vector and in the host DNA. In the majority of the cases (90%), integration led to cointegrate formation, and in some cases, deletions or rearrangements occurred during the recombination event. Insertions were found to be quite stable even in the absence of selective pressure.

Integration of narrow-host-range vectors from Escherichia coli into the genomes of amino acid-producing corynebacteria after intergeneric conjugation.

PubMed Central

Mateos, L M; Schäfer, A; Kalinowski, J; Martin, J F; Pühler, A

1996-01-01

Conjugative transfer of mobilizable derivatives of the Escherichia coli narrow-host-range plasmids pBR322, pBR325, pACYC177, and pACYC184 from E. coli to species of the gram-positive genera Corynebacterium and Brevibacterium resulted in the integration of the plasmids into the genomes of the recipient bacteria. Transconjugants appeared at low frequencies and reproducibly with a delay of 2 to 3 days compared with matings with replicative vectors. Southern analysis of corynebacterial transconjugants and nucleotide sequences from insertion sites revealed that integration occurs at different locations and that different parts of the vector are involved in the process. Integration is not dependent on indigenous insertion sequence elements but results from recombination between very short homologous DNA segments (8 to 12 bp) present in the vector and in the host DNA. In the majority of the cases (90%), integration led to cointegrate formation, and in some cases, deletions or rearrangements occurred during the recombination event. Insertions were found to be quite stable even in the absence of selective pressure. PMID:8824624

Conversion of evanescent Lamb waves into propagating waves via a narrow aperture edge.

PubMed

Yan, Xiang; Yuan, Fuh-Gwo

2015-06-01

This paper presents a quantitative study of conversion of evanescent Lamb waves into propagating in isotropic plates. The conversion is substantiated by prescribing time-harmonic Lamb displacements/tractions through a narrow aperture at an edge of a semi-infinite plate. Complex-valued dispersion and group velocity curves are employed to characterize the conversion process. The amplitude coefficient of the propagating Lamb modes converted from evanescent is quantified based on the complex reciprocity theorem via a finite element analysis. The power flow generated into the plate can be separated into radiative and reactive parts made on the basis of propagating and evanescent Lamb waves, where propagating Lamb waves are theoretically proved to radiate pure real power flow, and evanescent Lamb waves carry reactive pure imaginary power flow. The propagating power conversion efficiency is then defined to quantitatively describe the conversion. The conversion efficiency is strongly frequency dependent and can be significant. With the converted propagating waves from evanescent, sensors at far-field can recapture some localized damage information that is generally possessed in evanescent waves and may have potential application in structural health monitoring.

Composite oxygen ion transport element

DOEpatents

Chen, Jack C [Getzville, NY; Besecker, Charles J [Batavia, IL; Chen, Hancun [Williamsville, NY; Robinson, Earil T [Mentor, OH

2007-06-12

A composite oxygen ion transport element that has a layered structure formed by a dense layer to transport oxygen ions and electrons and a porous support layer to provide mechanical support. The dense layer can be formed of a mixture of a mixed conductor, an ionic conductor, and a metal. The porous support layer can be fabricated from an oxide dispersion strengthened metal, a metal-reinforced intermetallic alloy, a boron-doped Mo.sub.5Si.sub.3-based intermetallic alloy or combinations thereof. The support layer can be provided with a network of non-interconnected pores and each of said pores communicates between opposite surfaces of said support layer. Such a support layer can be advantageously employed to reduce diffusion resistance in any type of element, including those using a different material makeup than that outlined above.

Recycling of trace elements required for humans in CELSS.

PubMed

Ashida, A

1994-11-01

Recycle of complete nourishment necessary for human should be constructed in CELSS (Controlled Ecological Life Support Systems). Essential elements necessary for human support are categorized as major elements, semi-major elements and trace elements. Recently, trace elements have been identified from considerations of local diseases, food additive problems, pollution problems and adult diseases, consisting of Fe, Zn, Cu, Se, Co, F, Si, Mn, Cr, I, As, Mo, Ni, V, Sn, Li, Br, Cd, Pb, B. A review of the biogeochemical history of the earth's biosphere and the physiological nature of humans and plants explains some of the requirements. A possible route for intake of trace elements is considered that trace elements are dissolved in some chemical form in water, absorbed by plants through their roots and then transfered to human as foods. There may be a possibility that living things absorb some trace elements from atmosphere. Management and recycling of trace elements in CELSS is discussed.

Recycling of trace elements required for humans in CELSS

NASA Astrophysics Data System (ADS)

Ashida, A.

1994-11-01

Recycle of complete nourishment necessary for human should be constructed in CELSS (Controlled Ecological Life Support Systems). Essential elements necessary for human support are categorized as major elements, semi-major elements and trace elements. Recently, trace elements have been identified from considerations of local diseases, food additive problems, pollution problems and adult diseases, consisting of Fe, Zn, Cu, Se, Co, F, Si, Mn, Cr, I, As, Mo, Ni, V, Sn, Li, Br, Cd, Pb, B. A review of the biogeochemical history of the earth's biosphere and the physiological nature of humans and plants explains some of the requirements. A possible route for intake of trace elements is considered that trace elements are dissolved in some chemical form in water, absorbed by plants through their roots and then transfered to human as foods. There may be a posibility that living things absorb some trace elements from atmosphere. Management and recycling of trace elements in CELSS is discussed.

Chromatin insulation by a transcriptional activator

PubMed Central

Sutter, Nathan B.; Scalzo, David; Fiering, Steven; Groudine, Mark; Martin, David I. K.

2003-01-01

In eukaryotic genomes, transcriptionally active regions are interspersed with silent chromatin that may repress genes in its vicinity. Chromatin insulators are elements that can shield a locus from repressive effects of flanking chromatin. Few such elements have been characterized in higher eukaryotes, but transcriptional activating elements are an invariant feature of active loci and have been shown to suppress transgene silencing. Hence, we have assessed the ability of a transcriptional activator to cause chromatin insulation, i.e., to relieve position effects at transgene integration sites in cultured cells. The transgene contained a series of binding sites for the metal-inducible transcriptional activator MTF, linked to a GFP reporter. Clones carrying single integrated transgenes were derived without selection for expression, and in most clones the transgene was silent. Induction of MTF resulted in transition of the transgene from the silent to the active state, prolongation of the active state, and a marked narrowing of the range of expression levels at different genomic sites. At one genomic site, prolonged induction of MTF resulted in suppression of transgene silencing that persisted after withdrawal of the induction stimulus. These results are consistent with MTF acting as a chromatin insulator and imply that transcriptional activating elements can insulate active loci against chromatin repression. PMID:12547916

Particle impactor assembly for size selective high volume air sampler

DOEpatents

Langer, Gerhard

1988-08-16

Air containing entrained particulate matter is directed through a plurality of parallel, narrow, vertically oriented impactor slots of an inlet element toward an adjacently located, relatively large, dust impaction surface preferably covered with an adhesive material. The air flow turns over the impaction surface, leaving behind the relatively larger particles according to the human thoracic separation system and passes through two elongate exhaust apertures defining the outer bounds of the impaction collection surface to pass through divergent passages which slow down and distribute the air flow, with entrained smaller particles, over a fine filter element that separates the fine particles from the air. The elongate exhaust apertures defining the impaction collection surface are spaced apart by a distance greater than the lengths of elongate impactor slots in the inlet element and are oriented to be normal thereto. By appropriate selection of dimensions and the number of impactor slots air flow through the inlet element is provided a nonuniform velocity distribution with the lower velocities being obtained near the center of the impactor slots, in order to separate out particles larger than a certain predetermined size on the impaction collection surface. The impaction collection surface, even in a moderately sized apparatus, is thus relatively large and permits the prolonged sampling of air for periods extending to four weeks.

The use of olive tree (Olea europaea L.) leaves as a bioindicator for environmental pollution in the Province of Aydın, Turkey.

PubMed

Turan, Dilek; Kocahakimoglu, Cemre; Kavcar, Pınar; Gaygısız, Handan; Atatanir, Levent; Turgut, Cafer; Sofuoglu, Sait C

2011-03-01

In this study, olive tree leaves, collected from 50 sampling sites throughout the Province of Aydın, Turkey, were used to estimate level of pollution by measuring Al, As, B, Ba, Ca, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Na, Ni, Pb, Sr, and Zn concentrations and calculating pollution factor (PF) values. After sample preparation, collected leaves were microwave digested, and extracts were analyzed by an inductively coupled plasma-mass spectrometer. The maximum PF values were ≥10 for a number of elements ranging from 11-13 (Al, As, Cr, Fe, Mn, Ni) to >100 for Cu, Li, and Na. Urban-rural and roadside-nonroadside concentration comparisons showed that some of the elements (As, Cu, and Pb) were at significantly higher levels on urban and/or roadside sampling sites. Correlations and factor analysis showed that there may be common sources for some elements, which included several soil types and anthropogenic activities. Based on the results of the statistical source apportionment, possible sources were narrowed down with help of the constructed elemental concentration maps. In conclusion, utilization of olive tree leaves for biomonitoring and assessment of environmental pollution was shown to be possible in the Mediterranean region where they are indigenous and cultivated.

Epidermal Growth Factor Signaling towards Proliferation: Modeling and Logic Inference Using Forward and Backward Search

PubMed Central

Riesco, Adrián; Santos-Buitrago, Beatriz; De Las Rivas, Javier; Knapp, Merrill; Talcott, Carolyn

2017-01-01

In biological systems, pathways define complex interaction networks where multiple molecular elements are involved in a series of controlled reactions producing responses to specific biomolecular signals. These biosystems are dynamic and there is a need for mathematical and computational methods able to analyze the symbolic elements and the interactions between them and produce adequate readouts of such systems. In this work, we use rewriting logic to analyze the cellular signaling of epidermal growth factor (EGF) and its cell surface receptor (EGFR) in order to induce cellular proliferation. Signaling is initiated by binding the ligand protein EGF to the membrane-bound receptor EGFR so as to trigger a reactions path which have several linked elements through the cell from the membrane till the nucleus. We present two different types of search for analyzing the EGF/proliferation system with the help of Pathway Logic tool, which provides a knowledge-based development environment to carry out the modeling of the signaling. The first one is a standard (forward) search. The second one is a novel approach based on narrowing, which allows us to trace backwards the causes of a given final state. The analysis allows the identification of critical elements that have to be activated to provoke proliferation. PMID:28191459

Effect of catalyst calcination temperature in the visible light photocatalytic oxidation of gaseous formaldehyde by multi-element doped titanium dioxide.

PubMed

de Luna, Mark Daniel G; Laciste, Maricris T; Tolosa, Nolan C; Lu, Ming-Chun

2018-03-20

The present study investigates the influence of calcination temperature on the properties and photoactivity of multi-element doped TiO 2 . The photocatalysts were prepared by incorporating silver (Ag), fluorine (F), nitrogen (N), and tungsten (W) into the TiO 2 structure via the sol-gel method. Spectroscopic techniques were used to elucidate the correlation between the structural and optical properties of the doped photocatalyst and its photoactivity. XRD results showed that the mean crystallite size increased for undoped photocatalysts and decreased for the doped photocatalysts when calcination was done at higher temperatures. UV-Vis spectra showed that the absorption cut-off wavelength shifted towards the visible light region for the as-synthesized photocatalysts and band gap narrowing was attributed to multi-element doping and calcination. FTIR spectra results showed the shifting of OH-bending absorption bands towards increasing wave numbers. The activity of the photocatalysts was evaluated in terms of gaseous formaldehyde removal under visible light irradiation. The highest photocatalytic removal of gaseous formaldehyde was found at 88%. The study confirms the effectiveness of multi-element doped TiO 2 to remove gaseous formaldehyde in air by visible light photocatalysis and the results have a lot of potential to extend the application to other organic air contaminants.

Design and development of a unit element microstrip antenna for aircraft collision avoidance system

NASA Astrophysics Data System (ADS)

De, Debajit; Sahu, Prasanna Kumar

2017-10-01

Aircraft/traffic alert and collision avoidance system (ACAS/TCAS) is an airborne system which is designed to provide the service as a last defense equipment for avoiding mid-air collisions between the aircraft. In the existing system, four monopole stub-elements are used as ACAS directional antenna and one blade type element is used as ACAS omnidirectional antenna. The existing ACAS antenna has some drawbacks such as low gain, large beamwidth, frequency and beam tuning/scanning issues etc. Antenna issues like unwanted signals reception may create difficulties to identify the possible threats. In this paper, the focus is on the design and development of a unit element microstrip antenna which can be used for ACAS application and to overcome the possible limitations associated with the existing techniques. Two proposed antenna models are presented here, which are single feed and dual feed microstrip dual patch slotted antenna. These are designed and simulated in CST Microwave Studio tool. The performance and other antenna characteristics have been explored from the simulation results followed by the antenna fabrication and measurement. A good reflection coefficient, Voltage Standing Wave Ratio (VSWR), narrow beamwidth, perfect directional radiation pattern, high gain and directivity make this proposed antenna a good candidate for this application.

PM source identification at Sunland Park, New Mexico, using a simple heuristic meteorological and chemical analysis.

PubMed

Li, Wen-Whai; Cardenas, Nidia; Walton, John; Trujillo, David; Morales, Hugo; Arimoto, Richard

2005-03-01

The causes for evening low-wind PM10 and PM2.5 peaks at Sunland Park, NM, were investigated by using wind sector analysis and by assessing relationships between PM loadings and meteorological parameters through canonical ordination analysis. Both PM10 and PM2.5 concentrations during the evening hours accounted for approximately 50% of their respective 24-hr averages, and the PM10 was mainly composed of coarse material (PM10-2.5 amounted to 77% of PM10). A wind sector analysis based on data from three surface meteorological monitoring stations in the region narrowed the potential source region for PM10 and PM2.5 to an area within a few kilometers south of Sunland Park. Canonical ordination analysis confirmed that the peak frequently occurred under stable conditions with weak southerly winds. Chemical analyses of PM showed that elemental and organic carbon (EC and OC, respectively) dominate PM2.5 and inorganic elements dominate PM10-2.5. The combined data for EC/OC, geologic elements, and various trace elements indicate that under low wind and stable conditions, traffic-related PM emissions (motor vehicle exhausts and re-suspended road dust) from the south of the site are the most likely sources for the evening PM10 and PM2.5 peaks.

Source Methodology for Turbofan Noise Prediction (SOURCE3D Technical Documentation)

NASA Technical Reports Server (NTRS)

Meyer, Harold D.

1999-01-01

This report provides the analytical documentation for the SOURCE3D Rotor Wake/Stator Interaction Code. It derives the equations for the rotor scattering coefficients and stator source vector and scattering coefficients that are needed for use in the TFANS (Theoretical Fan Noise Design/Prediction System). SOURCE3D treats the rotor and stator as isolated source elements. TFANS uses this information, along with scattering coefficients for inlet and exit elements, and provides complete noise solutions for turbofan engines. SOURCE3D is composed of a collection of FORTRAN programs that have been obtained by extending the approach of the earlier V072 Rotor Wake/Stator Interaction Code. Similar to V072, it treats the rotor and stator as a collection of blades and vanes having zero thickness and camber contained in an infinite, hardwall annular duct. SOURCE3D adds important features to the V072 capability-a rotor element, swirl flow and vorticity waves, actuator disks for flow turning, and combined rotor/actuator disk and stator/actuator disk elements. These items allow reflections from the rotor, frequency scattering, and mode trapping, thus providing more complete noise predictions than previously. The code has been thoroughly verified through comparison with D.B. Hanson's CUP2D two- dimensional code using a narrow annulus test case.

Epidermal Growth Factor Signaling towards Proliferation: Modeling and Logic Inference Using Forward and Backward Search.

PubMed

Riesco, Adrián; Santos-Buitrago, Beatriz; De Las Rivas, Javier; Knapp, Merrill; Santos-García, Gustavo; Talcott, Carolyn

2017-01-01

In biological systems, pathways define complex interaction networks where multiple molecular elements are involved in a series of controlled reactions producing responses to specific biomolecular signals. These biosystems are dynamic and there is a need for mathematical and computational methods able to analyze the symbolic elements and the interactions between them and produce adequate readouts of such systems. In this work, we use rewriting logic to analyze the cellular signaling of epidermal growth factor (EGF) and its cell surface receptor (EGFR) in order to induce cellular proliferation. Signaling is initiated by binding the ligand protein EGF to the membrane-bound receptor EGFR so as to trigger a reactions path which have several linked elements through the cell from the membrane till the nucleus. We present two different types of search for analyzing the EGF/proliferation system with the help of Pathway Logic tool, which provides a knowledge-based development environment to carry out the modeling of the signaling. The first one is a standard (forward) search. The second one is a novel approach based on narrowing , which allows us to trace backwards the causes of a given final state. The analysis allows the identification of critical elements that have to be activated to provoke proliferation.

Competing effects of pain and fear of pain on postural control in low back pain?

PubMed

Mazaheri, Masood; Heidari, Elham; Mostamand, Javid; Negahban, Hossein; van Dieen, Jaap H

2014-12-01

A cross-sectional, observational study. To determine whether pain and fear of pain have competing effects on postural sway in patients with low back pain (LBP). Competing effects of pain and pain-related fear on postural control can be proposed as the likely explanation for inconsistent results regarding postural sway in the LBP literature. We hypothesized that although pain might increase postural sway, fear of pain might reduce sway through an increased cognitive effort or increased cocontraction to restrict body movement. The cognitive strategy would be less effective under dual-task conditions and the cocontraction strategy was expected to be less effective when standing on a narrow base of support surface. Postural sway was measured in combined conditions of base of support (full and narrow) and cognitive loading (single and dual tasks) in 3 experimental groups with current LBP, recent LBP, and no LBP. Sway amplitude, path length, mean power frequency, and sample entropy were extracted from center-of-pressure data. The current-LBP group and recent-LBP group reported significantly different levels of pain, but similar levels of pain catastrophizing and kinesiophobia. The current-LBP group tended to display larger sway amplitudes in the anteroposterior direction compared with the other 2 groups. Mean power frequency values in mediolateral direction were lower in patients with the current LBP compared with recent LBP. Smaller sample entropy was found in the current-LBP group than the other groups in most experimental conditions, particularly when standing on a narrow base of support. Alterations of postural sway are mostly mediated by pain but not pain-related fear. LBP tends to increase sway amplitude, which seems to be counteracted by increased effort invested in postural control leading to decreased frequency and increased regularity of sway particularly under increased task demands. Cross-sectional study.

HIGH ENERGY GASEOUS DISCHARGE DEVICES

DOEpatents

Josephson, V.

1960-02-16

The high-energy electrical discharge device described comprises an envelope, a pair of main discharge electrodes supported in opposition in the envelope, and a metallic shell symmetrically disposed around and spaced from the discharge path between the electrodes. The metallic shell comprises a first element of spaced helical turns of metallic material and a second element of spaced helical turns of methllic material insulatedly supported in superposition outside the first element and with the turns overlapping the gap between the turns of the first element.

Orbital operations study. Volume 2: Interfacing activities analysis. Part 4: Support operations activity group

NASA Technical Reports Server (NTRS)

Steinwachs, W. L.; Patrick, J. W.; Galvin, D. M.; Turkel, S. H.

1972-01-01

The findings of the support operations activity group of the orbital operations study are presented. Element interfaces, alternate approaches, design concepts, operational procedures, functional requirements, design influences, and approach selection are presented. The following areas are considered: (1) crew transfer, (2) cargo transfer, (3) propellant transfer, (4) attached element operations, and (5) attached element transport.

36. DETAILS AND SECTIONS OF SHIELDING TANK, FUEL ELEMENT SUPPORT ...

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

36. DETAILS AND SECTIONS OF SHIELDING TANK, FUEL ELEMENT SUPPORT FRAME AND SUPPORT PLATFORM, AND SAFETY MECHANISM ASSEMBLY (SPRING-LOADED HINGE). F.C. TORKELSON DRAWING NUMBER 842-ARVFS-701-S-1. INEL INDEX CODE NUMBER: 075 0701 60 851 151975. - Idaho National Engineering Laboratory, Advanced Reentry Vehicle Fusing System, Scoville, Butte County, ID

Association of Broad- vs Narrow-Spectrum Antibiotics With Treatment Failure, Adverse Events, and Quality of Life in Children With Acute Respiratory Tract Infections.

PubMed

Gerber, Jeffrey S; Ross, Rachael K; Bryan, Matthew; Localio, A Russell; Szymczak, Julia E; Wasserman, Richard; Barkman, Darlene; Odeniyi, Folasade; Conaboy, Kathryn; Bell, Louis; Zaoutis, Theoklis E; Fiks, Alexander G

2017-12-19

Acute respiratory tract infections account for the majority of antibiotic exposure in children, and broad-spectrum antibiotic prescribing for acute respiratory tract infections is increasing. It is not clear whether broad-spectrum treatment is associated with improved outcomes compared with narrow-spectrum treatment. To compare the effectiveness of broad-spectrum and narrow-spectrum antibiotic treatment for acute respiratory tract infections in children. A retrospective cohort study assessing clinical outcomes and a prospective cohort study assessing patient-centered outcomes of children between the ages of 6 months and 12 years diagnosed with an acute respiratory tract infection and prescribed an oral antibiotic between January 2015 and April 2016 in a network of 31 pediatric primary care practices in Pennsylvania and New Jersey. Stratified and propensity score-matched analyses to account for confounding by clinician and by patient-level characteristics, respectively, were implemented for both cohorts. Broad-spectrum antibiotics vs narrow-spectrum antibiotics. In the retrospective cohort, the primary outcomes were treatment failure and adverse events 14 days after diagnosis. In the prospective cohort, the primary outcomes were quality of life, other patient-centered outcomes, and patient-reported adverse events. Of 30 159 children in the retrospective cohort (19 179 with acute otitis media; 6746, group A streptococcal pharyngitis; and 4234, acute sinusitis), 4307 (14%) were prescribed broad-spectrum antibiotics including amoxicillin-clavulanate, cephalosporins, and macrolides. Broad-spectrum treatment was not associated with a lower rate of treatment failure (3.4% for broad-spectrum antibiotics vs 3.1% for narrow-spectrum antibiotics; risk difference for full matched analysis, 0.3% [95% CI, -0.4% to 0.9%]). Of 2472 children enrolled in the prospective cohort (1100 with acute otitis media; 705, group A streptococcal pharyngitis; and 667, acute sinusitis), 868 (35%) were prescribed broad-spectrum antibiotics. Broad-spectrum antibiotics were associated with a slightly worse child quality of life (score of 90.2 for broad-spectrum antibiotics vs 91.5 for narrow-spectrum antibiotics; score difference for full matched analysis, -1.4% [95% CI, -2.4% to -0.4%]) but not with other patient-centered outcomes. Broad-spectrum treatment was associated with a higher risk of adverse events documented by the clinician (3.7% for broad-spectrum antibiotics vs 2.7% for narrow-spectrum antibiotics; risk difference for full matched analysis, 1.1% [95% CI, 0.4% to 1.8%]) and reported by the patient (35.6% for broad-spectrum antibiotics vs 25.1% for narrow-spectrum antibiotics; risk difference for full matched analysis, 12.2% [95% CI, 7.3% to 17.2%]). Among children with acute respiratory tract infections, broad-spectrum antibiotics were not associated with better clinical or patient-centered outcomes compared with narrow-spectrum antibiotics, and were associated with higher rates of adverse events. These data support the use of narrow-spectrum antibiotics for most children with acute respiratory tract infections.

The ESPAS e-infrastructure: Access to data from near-Earth space

NASA Astrophysics Data System (ADS)

Belehaki, Anna; James, Sarah; Hapgood, Mike; Ventouras, Spiros; Galkin, Ivan; Lembesis, Antonis; Tsagouri, Ioanna; Charisi, Anna; Spogli, Luca; Berdermann, Jens; Häggström, Ingemar; ESPAS Consortium

2016-10-01

ESPAS, the ;near-Earth space data infrastructure for e-science; is a data e-infrastructure facilitating discovery and access to observations, ground-based and space borne, and to model predictions of the near-Earth space environment, a region extending from the Earth's atmosphere up to the outer radiation belts. ESPAS provides access to metadata and/or data from an extended network of data providers distributed globally. The interoperability of the heterogeneous data collections is achieved with the adoption and adaption of the ESPAS data model which is built entirely on ISO 19100 series geographic information standards. The ESPAS data portal manages a vocabulary of space physics keywords that can be used to narrow down data searches to observations of specific physical content. Such content-targeted search is an ESPAS innovation provided in addition to the commonly practiced data selection by time, location, and instrument. The article presents an overview of the architectural design of the ESPAS system, of its data model and ontology, and of interoperable services that allow the discovery, access and download of registered data. Emphasis is given to the standardization, and expandability concepts which represent also the main elements that support the building of long-term sustainability activities of the ESPAS e-infrastructure.

Solid-state ensemble of highly entangled photon sources at rubidium atomic transitions

NASA Astrophysics Data System (ADS)

Zopf, Michael; Keil, Robert; Chen, Yan; HöFer, Bianca; Zhang, Jiaxiang; Ding, Fei; Schmidt, Oliver G.

Semiconductor InAs/GaAs quantum dots grown by the Stranski-Krastanov method are among the leading candidates for the deterministic generation of polarization entangled photon pairs. Despite remarkable progress in the last twenty years, many challenges still remain for this material, such as the extremely low yield (< 1% quantum dots can emit entangled photons), the low degree of entanglement, and the large wavelength distribution. Here we show that, with an emerging family of GaAs/AlGaAs quantum dots grown by droplet etching and nanohole infilling, it is possible to obtain a large ensemble (close to 100%) of polarization-entangled photon emitters on a wafer without any post-growth tuning. Under pulsed resonant two-photon excitation, all measured quantum dots emit single pairs of entangled photons with ultra-high purity, high degree of entanglement (fidelity up to F=0.91, with a record high concurrence C=0.90), and ultra-narrow wavelength distribution at rubidium transitions. Therefore, a solid-state quantum repeater - among many other key enabling quantum photonic elements - can be practically implemented with this new material. Financially supported by BMBF Q.Com-H (16KIS0106) and the Euro- pean Union Seventh Framework Programme 209 (FP7/2007-2013) under Grant Agreement No. 601126 210 (HANAS).

Mapping Strain Gradients in the FIB-Structured InGaN/GaN Multilayered Films with 3D X-ray Microbeam

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

Barabash, Rozaliya; Gao, Yanfei; Ice, Gene E

2010-01-01

This research presents a combined experimental-modeling study of lattice rotations and deviatoric strain gradients induced by focused-ion beam (FIB) milling in nitride heterostructures. 3D X-ray polychromatic microdiffraction (PXM) is used to map the local lattice orientation distribution in FIB-structured areas. Results are discussed in connection with microphotoluminescence ({mu}-PL), fluorescent analysis, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) data. It is demonstrated that FIB-milling causes both direct and indirect damage to the InGaN/GaN layers. In films subjected to direct ion beam impact, a narrow amorphidized top layer is formed. Near the milling area, FIB-induced stress relaxation and formation ofmore » complicated 3D strain fields are observed. The resulting lattice orientation changes are found to correlate with a decrease and/or loss of PL intensity, and agree well with finite element simulations of the three-dimensional strain fields near the relaxed trenches. Experimentally, it is found that the lattice surface normal has an in-plane rotation, which only appears in simulations when the GaN-substrate lattice mismatch annihilates the InGaN-substrate mismatch. This behavior further supports the notion that the film/substrate interface is incoherent.« less

Mapping strain gradients in the FIB-structured InGaN/GaN multilayered films with 3D x-ray microbeam.

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

Barabash, R. I.; Gao, Y. F.; Ice, G. E.

2010-11-25

This research presents a combined experimental-modeling study of lattice rotations and deviatoric strain gradients induced by focused-ion beam (FIB) milling in nitride heterostructures. 3D X-ray polychromatic microdiffraction (PXM) is used to map the local lattice orientation distribution in FIB-structured areas. Results are discussed in connection with microphotoluminescence ({mu}-PL), fluorescent analysis, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) data. It is demonstrated that FIB-milling causes both direct and indirect damage to the InGaN/GaN layers. In films subjected to direct ion beam impact, a narrow amorphidized top layer is formed. Near the milling area, FIB-induced stress relaxation and formation ofmore » complicated 3D strain fields are observed. The resulting lattice orientation changes are found to correlate with a decrease and/or loss of PL intensity, and agree well with finite element simulations of the three-dimensional strain fields near the relaxed trenches. Experimentally, it is found that the lattice surface normal has an in-plane rotation, which only appears in simulations when the GaN-substrate lattice mismatch annihilates the InGaN-substrate mismatch. This behavior further supports the notion that the film/substrate interface is incoherent.« less

Changes in hyperspectral reflectance signatures of lettuce leaves in response to macronutrient deficiencies

NASA Astrophysics Data System (ADS)

Pacumbaba, R. O.; Beyl, C. A.

2011-07-01

The adaptation of specific remote sensing and hyperspectral analysis techniques for the determination of incipient nutrient stress in plants could allow early detection and precision supplementation for remediation, important considerations for minimizing mass of advanced life support systems on space station and long term missions. This experiment was conducted to determine if hyperspectral reflectance could be used to detect nutrient stress in Lactuca sativa L. cv. Black Seeded Simpson. Lettuce seedlings were grown for 90 days in a greenhouse or growth chamber in vermiculite containing modified Hoagland's nutrient solution with key macronutrient elements removed in order to induce a range of nutrient stresses, including nitrogen, phosphorus, potassium, calcium, and magnesium. Leaf tissue nutrient concentrations were compared with corresponding spectral reflectances taken at the end of 90 days. Spectral reflectances varied with growing location, position on the leaf, and nutrient deficiency treatment. Spectral responses of lettuce leaves under macronutrient deficiency conditions showed an increase in reflectance in the red, near red, and infrared wavelength ranges. The data obtained suggest that spectral reflectance shows the potential as a diagnostic tool in predicting nutrient deficiencies in general. Overlapping of spectral signatures makes the use of wavelengths of narrow bandwidths or individual bands for the discrimination of specific nutrient stresses difficult without further data processing.

In vivo degradation effects of alloy MgNd2 in contact with mucous tissue.

PubMed

Seitz, J-M; Eifler, R; Weber, C; Lenarz, T H; Maier, H J; Durisin, M

2015-07-01

Magnesium alloys are currently being investigated for use as resorbable biomaterials. Various applications for magnesium based implant materials have already been presented. Currently, stents and structures that sustain diseased or narrowed vessels seem to be the most promising areas. This study focuses on the use of a magnesium fluoride (MgF2 ) coated magnesium neodymium based alloy (MgNd2 ) and its use as a postsurgery stent material to avoid proliferation in the sinus region. Simple cylindrical shaped specimens were sown to the sinus' mucosa of pigs and left in place for different periods of time to investigate the long-term corrosion resistance of the alloy and its coating during direct contact with physiological tissue. Investigations made within this study explicitly focused on the corrosive behavior of the alloy in the region of a physiological sinus. Thus, losses in mass and volume, and element analyses were considered to obtain information about the specimens' corrosion performance over time. Furthermore, micrographs support the alloy specific corrosion type analyses which focus on grain boundary effects. This study demonstrates the general in vivo applicability of fluoride coated MgNd2 . The progress of corrosion was determined to be adequate and homogeneous over a total period of 180 days. © 2014 Wiley Periodicals, Inc.

Preparation of the spacer for narrow electrode gap configuration in ionization-based gas sensor

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

Saheed, Mohamed Shuaib Mohamed; Mohamed, Norani Muti; Burhanudin, Zainal Arif

2012-09-26

Carbon nanotubes (CNTs) have started to be developed as the sensing element for ionization-based gas sensors due to the demand for improved sensitivity, selectivity, stability and other sensing properties beyond what can be offered by the conventional ones. Although these limitations have been overcome, the problems still remain with the conventional ionization-based gas sensors in that they are bulky and operating with large breakdown voltage and high temperature. Recent studies have shown that the breakdown voltage can be reduced by using nanostructured electrodes and narrow electrode gap. Nanostructured electrode in the form of aligned CNTs array with evenly distributed nanotipsmore » can enhance the linear electric field significantly. The later is attributed to the shorter conductivity path through narrow electrode gap. The paper presents the study on the design consideration in order to realize ionization based gas sensor using aligned carbon nanotubes array in an optimum sensor configuration with narrow electrode gap. Several deposition techniques were studied to deposit the spacer, the key component that can control the electrode gap. Plasma spray deposition, electron beam deposition and dry oxidation method were employed to obtain minimum film thickness around 32 {mu}m. For plasma spray method, sand blasting process is required in order to produce rough surface for strong bonding of the deposited film onto the surface. Film thickness, typically about 39 {mu}m can be obtained. For the electron beam deposition and dry oxidation, the film thickness is in the range of nanometers and thus unsuitable to produce the spacer. The deposited multilayer film consisting of copper, alumina and ferum on which CNTs array will be grown was found to be removed during the etching process. This is attributed to the high etching rate on the thin film which can be prevented by reducing the rate and having a thicker conductive copper film.« less

Stoichiometry and climatic stress drive respiration and nutrient dynamics of beech litter decomposition

NASA Astrophysics Data System (ADS)

Keiblinger, Katharina Maria; Hämmerle, Ieda; Zechmeister-Boltenstern, Sophie

2010-05-01

Little is known about how the variance in resources in terms of carbon (C), nitrogen (N), phosphorus (P) ratios affects respiration and nutrient dynamics. To elucidate how resource quantity and stoichiometry affect the decomposition process of beech (Fagus sylvatica) litter a terrestrial microcosm experiment was conducted. Our aim was to follow changes of beech litter stoichiometry and biogeochemical processes, and to quantify element losses as affected by temperature and moisture extremes. In addition to gaseous element losses (CO2) we examined the release of nutrients prone to leaching and the importance of environmental controls. We addressed mechanisms and pathways of carbon, nitrogen and phosphorus losses. In our experiment sterilised dried leaves were inoculated with a litter-soil suspension from a beech forest in order to ensure similar starting conditions. Beech litter from different Austrian sites covering C:N ratios from 45 to 66 and C:P ratios from 652 to 1467 were incubated at 15°C for six months. The water content was adjusted to 60% at regular intervals to keep the moisture constant. To monitor transient and persistent influences of environmental stress, the microcosms were subject to extreme changes in temperature (+30°C and -20°C) and moisture (draught) after an incubation time of three months. Litter stoichiometries (C:N, C:P) turned out to be strong predictors for respiration, and nitrogen, and phosphorous losses. (i) Litter with narrow litter C:nutrient ratios decomposed faster than litter with wider litter C:nutrient ratios; and therefore showed higher respiration rates. (ii) Increased nutrient losses as leachates were observed for high quality leaf litter i.e. inorganic nitrogen losses for sites with narrow litter C:N ratios and phosphate was released more quickly in sites with narrow C:P ratios. There was a strong functional response of the microbial community to environmental extremes. Respiration increased upon temperature extremes, especially in the litter with highest C:P ratio. A persistent effect of temperature extremes on NH4 and NO3 concentrations was observed for three months after stress application. However, the effect on PO4 concentrations was only transient. Environmental conditions had a strong affect on nutrient losses but only a minor affect on microbial carbon Cmic and microbial nitrogen Nmic. The impact of environmental stress (heat or freezing) on microbes in terms of Cmic, Nmic and C:Nmic was strongest in sites with narrow litter C:N ratios. Our results indicate a similar stoichiometric demand of microbes, with temporal changes which results in differences in nutrient cycling on substrates with different C:N:P ratios.

Speckles in interstellar radio-wave scattering

NASA Technical Reports Server (NTRS)

Desai, K. M.; Gwinn, C. R.; Reynolds, J.; King, E. A.; Jauncey, D.; Nicholson, G.; Flanagan, C.; Preston, R. A.; Jones, D. L.

1991-01-01

Observations of speckles in the scattering disk of the Vela pulsar are presented and speckle techniques for studying and circumventing scattering of radio waves by the turbulent interstellar plasma are discussed. The speckle pattern contains, in a hologrammatic fashion, complete information on the structure of the radio source as well as the distribution of the scattering material. Speckle observations of interstellar scattering of radio waves are difficult because of their characteristically short timescales and narrow bandwidths. Here, first observations are presented, taken at 13 cm wavelength with elements of the SHEVE VLBI network, of speckles in interstellar scattering.

Application of a demountable water-cooled hollow-cathode lamp to atomic-fluorescence spectrometry.

PubMed

Rossi, G; Omenetto, N

1969-02-01

A demountable water-cooled hollow-cathode lamp has been investigated as a primary source in atomic fluorescence spectrometry. The discharge current ranged from 300 to 500 mA, and the flowing argon pressure between 0.4 and 4 mbar. Sensitivities ranging from 0.03 to 2 mug ml were obtained for 12 elements. The performances of the hollow-cathode lamp and those of the customary metal vapour discharge lamps for thallium, indium and gallium are compared. The role of the narrowness of the exciting lines in increasing the signal-to-scattering ratios is stressed.

Sound transmission in narrow pipes with superimposed uniform mean flow and acoustic modelling of automobile catalytic converters

NASA Astrophysics Data System (ADS)

Dokumaci, E.

1995-05-01

The theory of Zwikker and Kosten for axisymmetric wave propagation in circular pipes has been extended to include the effect of uniform mean flow. This formulation can be used in acoustical modelling of both the honeycomb pipes in monolithic catalytic converters and the standard pipes in internal combustion engine exhaust lines. The effects of mean flow on the propagation constants are shown. Two-port elements for acoustic modelling of the honeycomb structure of monolithic catalytic converters are developed and applied to the prediction of the transmission loss characteristics.

NASA advanced turboprop research and concept validation program

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

Whitlow, J.B. Jr.; Sievers, G.K.

1988-01-01

NASA has determined by experimental and analytical effort that use of advanced turboprop propulsion instead of the conventional turbofans in the older narrow-body airline fleet could reduce fuel consumption for this type of aircraft by up to 50 percent. In cooperation with industry, NASA has defined and implemented an Advanced Turboprop (ATP) program to develop and validate the technology required for these new high-speed, multibladed, thin, swept propeller concepts. This paper presents an overview of the analysis, model-scale test, and large-scale flight test elements of the program together with preliminary test results, as available.

Hyperspectral remote sensing for terrestrial applications

USGS Publications Warehouse

Thenkabail, Prasad S.; Teluguntla, Pardhasaradhi G.; Murali Krishna Gumma,; Venkateswarlu Dheeravath,

2015-01-01

Remote sensing data are considered hyperspectral when the data are gathered from numerous wavebands, contiguously over an entire range of the spectrum (e.g., 400–2500 nm). Goetz (1992) defines hyperspectral remote sensing as “The acquisition of images in hundreds of registered, contiguous spectral bands such that for each picture element of an image it is possible to derive a complete reflectance spectrum.” However, Jensen (2004) defines hyperspectral remote sensing as “The simultaneous acquisition of images in many relatively narrow, contiguous and/or non contiguous spectral bands throughout the ultraviolet, visible, and infrared portions of the electromagnetic spectrum.

Spectrum Analyzers Incorporating Tunable WGM Resonators

NASA Technical Reports Server (NTRS)

Savchenkov, Anatoliy; Matsko, Andrey; Strekalov, Dmitry; Maleki, Lute

2009-01-01

A photonic instrument is proposed to boost the resolution for ultraviolet/ optical/infrared spectral analysis and spectral imaging allowing the detection of narrow (0.00007-to-0.07-picometer wavelength resolution range) optical spectral signatures of chemical elements in space and planetary atmospheres. The idea underlying the proposal is to exploit the advantageous spectral characteristics of whispering-gallery-mode (WGM) resonators to obtain spectral resolutions at least three orders of magnitude greater than those of optical spectrum analyzers now in use. Such high resolutions would enable measurement of spectral features that could not be resolved by prior instruments.

Thanatophoric Dwarfism

PubMed Central

Shah, K.; Astley, R.; Cameron, A. H.

1973-01-01

A review of the radiographs of children previously classified as achondroplasiacs revealed six thanatophoric dwarfs. The main radiological differentiating features were the greater degree of shortening of the long bones, including the fibula, the curvature of the femora, the very small size of the thorax and, particularly, the very narrow ossified elements of the vertebral bodies. Perhaps the most important aspect of differential diagnosis lies in recognition in utero. The reported association with clover-leaf deformity of the skull in sibs provides the strongest evidence for genetic differentiation from classical achondroplasia. More evidence might be obtained by a widespread search through hospital radiological museums. Images PMID:4204337

Negative emotional content disrupts the coherence of episodic memories.

PubMed

Bisby, James A; Horner, Aidan J; Bush, Daniel; Burgess, Neil

2018-02-01

Events are thought to be stored in episodic memory as coherent representations, in which the constituent elements are bound together so that a cue can trigger reexperience of all elements via pattern completion. Negative emotional content can strongly influence memory, but opposing theories predict strengthening or weakening of memory coherence. Across a series of experiments, participants imagined a number of person-location-object events with half of the events including a negative element (e.g., an injured person), and memory was tested across all within event associations. We show that the presence of a negative element reduces memory for associations between event elements, including between neutral elements encoded after a negative element. The presence of a negative element reduces the coherence with which a multimodal event is remembered. Our results, supported by a computational model, suggest that coherent retrieval from neutral events is supported by pattern completion, but that negative content weakens associative encoding which impairs this process. Our findings have important implications for understanding the way traumatic events are encoded and support therapeutic strategies aimed at restoring associations between negative content and its surrounding context. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Technical challenges involved in supporting the Lambda Point Experiment

NASA Technical Reports Server (NTRS)

Petrac, D.; Israelsson, U.; Otth, D.; Simmons, L.; Staats, J.; Thompson, A.

1990-01-01

The Lambda Point Experiment (LPE) is one of the instruments included in the U.S. Microgravity Payload Mission 1 planned for one of the Space Shuttle flights in 1992. The objective of the experiment is to measure the heat capacity of liquid helium within a narrow interval around the transition between superfluid and normal helium (the lambda point) with an unprecedented temperature resolution of about 10 to the -10th. Multiple technical challenges are presented in the areas of structural support, safety analysis, and modal frequency tests. This paper describes the technical challenges of JPL's multidisciplinary involvement in support of these experiments in microgravity.

Rotating electric machine with fluid supported parts

DOEpatents

Smith, Jr., Joseph L.; Kirtley, Jr., James L.

1981-01-01

A rotating electric machine in which the armature winding thereof and other parts are supported by a liquid to withstand the mechanical stresses applied during transient overloads and the like. In particular, a narrow gap is provided between the armature winding and the stator which supports it and this gap is filled with an externally pressurized viscous liquid. The liquid is externally pressurized sufficiently to balance the static loads on the armature winding. Transient mechanical loads which deform the armature winding alter the gap dimensions and thereby additionally pressurize the viscous liquid to oppose the armature winding deformation and more nearly uniformly to distribute the resulting mechanical stresses.

Eye movement evidence for defocused attention in dysphoria--a perceptual span analysis.

PubMed

Brzezicka, Aneta; Krejtz, Izabela; von Hecker, Ulrich; Laubrock, Jochen

2012-07-01

The defocused attention hypothesis (von Hecker and Meiser, 2005) assumes that negative mood broadens attention, whereas the analytical rumination hypothesis (Andrews and Thompson, 2009) suggests a narrowing of the attentional focus with depression. We tested these conflicting hypotheses by directly measuring the perceptual span in groups of dysphoric and control subjects, using eye tracking. In the moving window paradigm, information outside of a variable-width gaze-contingent window was masked during reading of sentences. In measures of sentence reading time and mean fixation duration, dysphoric subjects were more pronouncedly affected than controls by a reduced window size. This difference supports the defocused attention hypothesis and seems hard to reconcile with a narrowing of attentional focus. Copyright © 2011 Elsevier B.V. All rights reserved.

The importance of surface recombination and energy-bandgap narrowing in p-n-junction silicon solar cells

NASA Technical Reports Server (NTRS)

Fossum, J. G.; Lindholm, F. A.; Shibib, M. A.

1979-01-01

Experimental data demonstrating the sensitivity of open-circuit voltage to front-surface conditions are presented for a variety of p-n-junction silicon solar cells. Analytical models accounting for the data are defined and supported by additional experiments. The models and the data imply that a) surface recombination significantly limits the open-circuit voltage (and the short-circuit current) of typical silicon cells, and b) energy-bandgap narrowing is important in the manifestation of these limitations. The models suggest modifications in both the structural design and the fabrication processing of the cells that would result in substantial improvements in cell performance. The benefits of one such modification - the addition of a thin thermal silicon-dioxide layer on the front surface - are indicated experimentally.

Experimental study of cryogen spray properties for application in dermatologic laser surgery.

PubMed

Aguilar, Guillermo; Majaron, Boris; Karapetian, Emil; Lavernia, Enrique J; Nelson, J Stuart

2003-07-01

Cryogenic sprays are used for cooling human skin during laser dermatologic surgery. In this paper, six straight-tube nozzles are characterized by photographs of cryogenic spray shapes, as well as measurements of average droplet diameter, velocity, and temperature. A single-droplet evaporation model to predict average spray droplet diameter and temperature is tested using the experimental data presented here. The results show two distinct spray patterns--sprays for 1.4-mm-diameter nozzles (wide nozzles) show significantly larger average droplet diameters and higher temperatures as a function of distance from the nozzle compared with those for 0.5-0.8-mm-diameter nozzles (narrow nozzles). These results complement and support previously reported studies, indicating that wide nozzles induce more efficient heat extraction than the narrow nozzles.

The Two Voices of Alzheimer's: Attitudes toward Brain Health by Diagnosed Individuals and Support Persons

ERIC Educational Resources Information Center

Beard, Renee L.; Fetterman, David J.; Wu, Bei; Bryant, Lucinda

2009-01-01

Purpose: Most individuals with Alzheimer's are cared for in their homes by unpaid family members. Research on caregiving focuses disproportionally on costs of care, service utilization, and negative psychosocial outcomes. Few narrative accounts of Alzheimer's exist; those that do suffer similar pejorative framings and narrow foci. No studies that…

Salvation from Narrow-Mindedness

ERIC Educational Resources Information Center

Rice, H. William

2008-01-01

Few Americans outside the Bible Belt understand the pressure placed on nonconformists in the South. The historical roots are deep: The people who had been defeated in the Civil War felt they had to stick together, so they feared the man or woman who spoke up and said, "I do not agree." As a Southerner whose parents passionately supported the…

Will Obama's "My Brother's Keeper" and Similar Initiatives Have a Positive Impact on Low-Income Students?

ERIC Educational Resources Information Center

Sanacore, Joseph

2017-01-01

Barack Obama's "My Brother's Keeper" is designed to narrow persistent gaps that boys and young men of color confront often and to help all young people achieve their potential in college and career. An important part of this initiative is comprehensive mentoring that supports students in schools and in communities. Because…

Early Childhood Teachers at the Center: A Qualitative Case Study of Professional Development in an Urban District

ERIC Educational Resources Information Center

Baker, Megina

2018-01-01

Professional development for early childhood educators (ECE PD) is an essential component of supporting a professional early childhood workforce. Yet research on ECE PD frequently centers on narrow fidelity data, while teachers' individual voices and teaching contexts are only rarely considered in order to understand teacher experiences with PD…

Fabrication and characterization of ultra-low noise narrow and wide band Josephson parametric amplifiers

NASA Astrophysics Data System (ADS)

Huang, Keqiang; Guo, Qiujiang; Song, Chao; Zheng, Yarui; Deng, Hui; Wu, Yulin; Jin, Yirong; Zhu, Xiaobo; Zheng, Dongning

2017-08-01

Not Available Project supported by the National Natural Science Foundation of China (Grant Nos. 91321208, 11374344, 11404386, 11574380, and 11674376), the Ministry of Science and Technology of China (Grant Nos. 2014CB921401 and 2016YFA0300601), and the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDB07010300).

Plasticity: The Online Learning Environment's Potential to Support Varied Learning Styles and Approaches

ERIC Educational Resources Information Center

Greener, Susan L.

2010-01-01

Purpose: "I can't do online learning". This is a surprisingly common response from professional postgraduate students who have a narrow view of what online learning might comprise. Images of screen-gazing at mega-bytes of text or childish multi-choice quizzes on CD-ROMs have encouraged strange reactionary responses from many otherwise…

Narrowing the Gap: Effects of Intervention on Developmental Trajectories in Autism

ERIC Educational Resources Information Center

Klintwall, Lars; Eldevik, Sigmund; Eikeseth, Svein

2015-01-01

Although still a matter of some debate, there is a growing body of research supporting Early and Intensive Behavioral Intervention as the intervention of choice for children with autism. Learning rate is an alternative to change in standard scores as an outcome measure in studies of early intervention. Learning rates can be displayed graphically…

Meeting 2020 Workforce Goals: The Role of Industry-College Collaboration and Goals for Instructional Design

ERIC Educational Resources Information Center

Yarnall, Louise

2014-01-01

Since the 1990s, federal programs for workforce training have aimed to transform the role of community colleges from narrow contract training to a broader role that encompasses strategic instructional program planning and innovation to support lifelong learning for a changing workforce and economic development (Jacobs & Teahen, 1996). Yet, to…

Tire/wheel concept

NASA Technical Reports Server (NTRS)

Harper, P. M., Sr. (Inventor)

1981-01-01

A tire and wheel assembly is disclosed in which a low profile pneumatic tire (having sidewalls which deflect inwardly under load) and a wheel (having a rim featuring a narrow central channel and extended rim flanges) form the combination. The extended rim flanges support the tire sidewalls under static and dynamic loading conditions to produce a combination particularly suited to aircraft applications.

Transformation of Marine Corps Artillery in Support of the 2015 Expeditionary Force

DTIC Science & Technology

2008-01-01

artillery electronics maintenance, and meterological sections in support ofsubordinate elements. On order, the Regiment assumes the primary civil...order capability), engineer, counterbattery radar, artillery electronics maintenance, and meterological sections in support ofsubordinate elements...www.tecom.usmc.mil. (accessed December 15,2007). Training and Education Command. MOS Roadmap: 0847 - Field Artillery Meterological Crew Member. Quantico

Outer midplane scrape-off layer profiles and turbulence in simulations of Alcator C-Mod inner-wall limited discharges

DOE PAGES

Halpern, Federico D.; LaBombard, Brian; Terry, James L.; ...

2017-06-27

A region of steep plasma gradients, the so-called ”narrow-feature”, has been found in the near scrape-off layer (SOL) of inner-wall limited (IWL) discharges. Dedicated IWL discharges were carried out in Alcator C-Mod [E.S. Marmar et al., Nucl. Fusion 55, (2015)] to study this phenomenon, allowing detailed observations of the plasma profiles and fluctuations. Langmuir probe (LP) measurements show a clear two decay length n e and T e profile structure at the outer midplane. The Gas-Puff Imaging (GPI) diagnostic shows large turbulent fluctuations across the last closed flux-surface, hence supporting the hypothesis that turbulent phenomena play a role in settingmore » the profile steepness. We have carried out the flux-driven non-linear turbulence simulations of two C-Mod discharges which allows a three-way comparison between LP, GPI, and simulation data. Observations and simulations correlate the steep gradient region characterizing the narrow feature with sheared poloidal flows and a deviation of the plasma potential from its floating value. Furthermore, the E x B shear rate exceeds the linear ballooning growth rate, indicating that the narrow feature could result from the effects of sheared flows, although causality could not be established. The fluctuation level in the narrow feature remains of order unity across the entire SOL, indicating that the transport reduction in the near-SOL cannot result from a simple quench rule.« less

Outer midplane scrape-off layer profiles and turbulence in simulations of Alcator C-Mod inner-wall limited discharges

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

Halpern, Federico D.; LaBombard, Brian; Terry, James L.

A region of steep plasma gradients, the so-called ”narrow-feature”, has been found in the near scrape-off layer (SOL) of inner-wall limited (IWL) discharges. Dedicated IWL discharges were carried out in Alcator C-Mod [E.S. Marmar et al., Nucl. Fusion 55, (2015)] to study this phenomenon, allowing detailed observations of the plasma profiles and fluctuations. Langmuir probe (LP) measurements show a clear two decay length n e and T e profile structure at the outer midplane. The Gas-Puff Imaging (GPI) diagnostic shows large turbulent fluctuations across the last closed flux-surface, hence supporting the hypothesis that turbulent phenomena play a role in settingmore » the profile steepness. We have carried out the flux-driven non-linear turbulence simulations of two C-Mod discharges which allows a three-way comparison between LP, GPI, and simulation data. Observations and simulations correlate the steep gradient region characterizing the narrow feature with sheared poloidal flows and a deviation of the plasma potential from its floating value. Furthermore, the E x B shear rate exceeds the linear ballooning growth rate, indicating that the narrow feature could result from the effects of sheared flows, although causality could not be established. The fluctuation level in the narrow feature remains of order unity across the entire SOL, indicating that the transport reduction in the near-SOL cannot result from a simple quench rule.« less

Comparison of liquid chemical sterilization with peracetic acid and ethylene oxide sterilization for long narrow lumens.

PubMed

Alfa, M J; DeGagne, P; Olson, N; Hizon, R

1998-10-01

The aim of this study was to determine how well peracetic acid liquid chemical sterilization (LCPAS) killed test organisms in the presence of 10% fetal bovine serum and 0.65% salt challenge (RPMI-S) compared with a 100% ethylene oxide (ETO) sterilizer and an ETO hydrochlorofluorocarbon (ETO-HCFC) sterilization method with long (125 cm), narrow (3-mm internal diameter) flexible lumens as the test carrier. The inoculated lumens were dried overnight before processing. The test organisms included Mycobacterium chelonei, Enterococcus faecalis, and Bacillus subtilis. For all 3 organisms tested, the LCPAS process resulted in a 6 log10 reduction in bacterial load compared with a 2.5 log10 to 6 log10 reduction for the 100% ETO and ETO-HCFC sterilizers. Sterilization was achieved for 100%, 61%, and 67% of the lumen test carriers for the LCPAS, 100% ETO, and ETO-HCFC sterilizers, respectively. The data indicate that of the sterilization methods evaluated, LCPAS was the most effective for sterilizing narrow flexible lumens in the presence of residual inorganic and organic soil. This effectiveness was achieved through a combination of organism wash-off and peracetic acid sterilant killing of organisms. Salt was the major compounding factor for effective ETO gas sterilization, because carriers inoculated with organisms in 10% fetal bovine serum alone all were sterilized by both 100% ETO and ETO-HCFC sterilization methods. Our data support the critical need to ensure adequate precleaning of narrow flexible lumen endoscopes before any sterilization method.

Load responsive hydrodynamic bearing

DOEpatents

Kalsi, Manmohan S.; Somogyi, Dezso; Dietle, Lannie L.

2002-01-01

A load responsive hydrodynamic bearing is provided in the form of a thrust bearing or journal bearing for supporting, guiding and lubricating a relatively rotatable member to minimize wear thereof responsive to relative rotation under severe load. In the space between spaced relatively rotatable members and in the presence of a liquid or grease lubricant, one or more continuous ring shaped integral generally circular bearing bodies each define at least one dynamic surface and a plurality of support regions. Each of the support regions defines a static surface which is oriented in generally opposed relation with the dynamic surface for contact with one of the relatively rotatable members. A plurality of flexing regions are defined by the generally circular body of the bearing and are integral with and located between adjacent support regions. Each of the flexing regions has a first beam-like element being connected by an integral flexible hinge with one of the support regions and a second beam-like element having an integral flexible hinge connection with an adjacent support region. A least one local weakening geometry of the flexing region is located intermediate the first and second beam-like elements. In response to application of load from one of the relatively rotatable elements to the bearing, the beam-like elements and the local weakening geometry become flexed, causing the dynamic surface to deform and establish a hydrodynamic geometry for wedging lubricant into the dynamic interface.

The Marine Engineers in Today’s MAGTF: Historical Perspective, Consequences and Alternatives

DTIC Science & Technology

2013-04-15

Inhibited Flexibility for Resource Leveling ...........................................................................17 Mission and Capability...21 Inhibited Flexibility for Resource Leveling ...ground combat element ( GCE ); an engineer support battalion (ESB) supports the logistics combat element (LCE); and engineer operations divisions

Small ICBM area narrowing report. Volume 3: Hard silo in patterned array basing mode

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

Not Available

The purpose of this report is to identify those areas that could potentially support deployment of the Small Intercontinental Ballistic Missile (ICBM) utilizing basing modes presently considered viable: the Hard Mobile Launcher in Random Movement, the Hard Mobile Launcher at Minuteman Facilities, or the Hard Silo in Patterned Array. Specifically, this report describes the process and the rationale supporting the application of Exclusionary and Evaluative Criteria and lists those locations that were eliminated through the application of these criteria. The remaining locations will be the subject of further investigations.

SCaN Network Ground Station Receiver Performance for Future Service Support

NASA Technical Reports Server (NTRS)

Estabrook, Polly; Lee, Dennis; Cheng, Michael; Lau, Chi-Wung

2012-01-01

Objectives: Examine the impact of providing the newly standardized CCSDS Low Density Parity Check (LDPC) codes to the SCaN return data service on the SCaN SN and DSN ground stations receivers: SN Current Receiver: Integrated Receiver (IR). DSN Current Receiver: Downlink Telemetry and Tracking (DTT) Receiver. Early Commercial-Off-The-Shelf (COTS) prototype of the SN User Service Subsystem Component Replacement (USS CR) Narrow Band Receiver. Motivate discussion of general issues of ground station hardware design to enable simple and cheap modifications for support of future services.

Defining the Marine Corps for the Long War

DTIC Science & Technology

2009-03-20

will adopt a specific regional orientation with specialized manpower and training. Foreign Area Officer (FAO), Regional Affairs Officer (RAO) and...less company grade in the Marine Corps Reserve is a natural and positive consequence of the way the Marine Corps develops its officer corps. It...Support Element • Law Enforcement Element 3rd ANGLICO 4th ANGLICO 3rd FORECON 4th FORECON supports supports supports SC MAGTF SOUTH * MFR directs each

Assessment of chemical element migration in soil-plant complex of Urov endemic localities of East Transbaikalia

NASA Astrophysics Data System (ADS)

Vadim V., Ermakov; Valentina, Danilova; Sabsbakhor, Khushvakhtova; Aklexander, Degtyarev; Sergey, Tyutikov; Victor, Berezkin; Elena, Karpova

2014-05-01

The comparative evaluation of the levels of biologically active chemical elements and their migration in the soil-plant complex of two Urov endemic locations in East Transbaikalia (Zolinsky and Uryumkansky) and background areas (Western Baikal region and the western area of the Trans-Baikal region) was conducted. The predominant soil-forming rocks in East Transbaikalia are weathering products of Proterozoic carbonated granitoids PR2. The surface rocks consist from granite, granodiorite, diorite quartz diorite, gabbro, norite, gabbro-norite and other. Soils - mountain and cryogenic meadow forests, mountain permafrost taiga podzolised, meadow alluvial, peaty meadow [2]. The paludification of narrow valleys and thermokarst phenomena are typical in Urov endemic localities. It reflects on the spotted of soil and differentiation of chemical composition of soils and plants. Most of the chemical elements in soils were determined by means of X-ray fluorescence, and trace elements in soils and plants - by atomic absorption spectrometry. The selenium content was measured by spectrofluorimetric method [3]. The research processed by methods of variation statistics. It was found that the soils of two locations of the Urov subregion of the biosphere were more enriched with iron, barium, calcium, uranium, thorium, phosphorus, and to a lesser extent strontium compared to background soils. The ratio of Ca: P was significantly higher in the soil of background areas, and Ca: Sr, on the contrary, in endemic soils. In assessing the migration of trace elements in soil-plant complex by means of the total content of trace elements and biological absorption coefficient found a marked accumulation by plants manganese, chromium, arsenic and weak plants accumulation of cobalt and nickel. Soil landscape is not much different in content of selenium, but its migration in plants was reduced in places of spread of Urov disease [1]. The concentrators of cadmium (leaves of different species of willow - Salicaceae) and selenium (needles of larch - Larix sibirica L.) were found among the plants. References 1. Ermakov V., Jovanovic L. Characteristics of selenium migration in soil-plant system of East Meshchera and Transbaikalia// J. Geochem. Explor., 2010. Vol. 107, 200-205. 2. Ermakov Vadim, Jovanovic Larisa, Berezkin Victor, Tyutikov Sergey, Danilogorskaya Anastasiya, Danilova Valentina, Krechetova Elena, Degtyarev Alexander, Khushvakhtova Sabsbakhor. Chemical assessment of soil and water of Urov biogeochemical provinces of Eastern Transbaikalia// Ecologica, 2012. Vol. 19, 69, 5-9. 3. Ermakov V.V., Tuytikov S.F. Khushvakhtova S.D., Danilova V.N. Boev V.A., Barabanschikova R.N., Chudinova E.A. Peculiarities of quantitative determination of selenium in biological materials// Bulletin of the Tyumen State University Press, 2010, 3, 206-214. Supported by the Russian Foundation for Basic Research, grant number 12-05-00141a.

Methodological approaches for using synchrotron X-ray fluorescence (SXRF) imaging as a tool in ionomics: Examples from Arabidopsis thaliana

PubMed Central

Hindt, Maria; Socha, Amanda L.; Zuber, Hélène

2013-01-01

Here we present approaches for using multi-elemental imaging (specifically synchrotron X-ray fluorescence microscopy, SXRF) in ionomics, with examples using the model plant Arabidopsis thaliana. The complexity of each approach depends on the amount of a priori information available for the gene and/or phenotype being studied. Three approaches are outlined, which apply to experimental situations where a gene of interest has been identified but has an unknown phenotype (Phenotyping), an unidentified gene is associated with a known phenotype (Gene Cloning) and finally, a Screening approach, where both gene and phenotype are unknown. These approaches make use of open-access, online databases with which plant molecular genetics researchers working in the model plant Arabidopsis will be familiar, in particular the Ionomics Hub and online transcriptomic databases such as the Arabidopsis eFP browser. The approaches and examples we describe are based on the assumption that altering the expression of ion transporters can result in changes in elemental distribution. We provide methodological details on using elemental imaging to aid or accelerate gene functional characterization by narrowing down the search for candidate genes to the tissues in which elemental distributions are altered. We use synchrotron X-ray microprobes as a technique of choice, which can now be used to image all parts of an Arabidopsis plant in a hydrated state. We present elemental images of leaves, stem, root, siliques and germinating hypocotyls. PMID:23912758

Multi-Element Behaviour Support as a Model for the Delivery of a Human Rights Based Approach for Working with People with Intellectual Disabilities and Behaviours that Challenge

ERIC Educational Resources Information Center

Doody, Christina

2009-01-01

This paper demonstrates the effectiveness of the multi-element behaviour support (MEBS) model in meeting the rights of persons with intellectual disabilities and behaviours that challenge. It does this through explicitly linking the multi-element model to the guiding principles of a human rights based approach (HRBA) using a vignette to…

Static knee alignment and its association with radiographic knee osteoarthritis.

PubMed

Teichtahl, A J; Cicuttini, F M; Janakiramanan, N; Davis, S R; Wluka, A E

2006-09-01

Although knee alignment is associated with the progression of knee osteoarthritis (OA), it is unclear which features that characterize radiographic OA are related to alignment. The aim of this study was to examine the relationship between static knee joint alignment (measured as a continuous variable) and the radiographic features of knee OA (joint space narrowing and osteophytes). One hundred and twenty one adults with symptomatic knee OA were recruited using a combined strategy including referral from specialist centres, arthritis support groups and media advertising. X-rays were performed to classify the severity of disease and to determine static knee alignment. Increasing varus knee alignment was associated with increasing risk of medial compartment joint space narrowing (P < 0.001) and osteophytes (P = 0.005). Increasing valgus knee alignment was associated with an increased risk for lateral compartment joint space narrowing (P < 0.001) and osteophytes (P = 0.002). This study has demonstrated that the static knee angle, measured as a continuous variable, is an important determinant of the compartment-specific features of radiographic knee OA. Further work is required to determine whether interventions aimed at correcting these relatively minor levels of varus and valgus angulation will have an effect on the risk of tibiofemoral OA.

Urban sparrows respond to a sexually selected trait with increased aggression in noise.

PubMed

Phillips, Jennifer N; Derryberry, Elizabeth P

2018-05-14

Animals modify acoustic communication signals in response to noise pollution, but consequences of these modifications are unknown. Vocalizations that transmit best in noise may not be those that best signal male quality, leading to potential conflict between selection pressures. For example, slow paced, narrow bandwidth songs transmit better in noise but are less effective in mate choice and competition than fast paced, wide bandwidth songs. We test the hypothesis that noise affects response to song pace and bandwidth in the context of competition using white-crowned sparrows (Zonotrichia leucophrys). We measure male response to song variation along a gradient of ambient noise levels in San Francisco, CA. We find that males discriminate between wide and narrow bandwidth songs but not between slow and fast paced songs. These findings are biologically relevant because songs in noisy areas tend to have narrow bandwidths. Therefore, this song phenotype potentially increases transmission distance in noise, but elicits weaker responses from competitors. Further, we find that males respond more strongly to stimuli in noisier conditions, supporting the 'urban anger' hypothesis. We suggest that noise affects male responsiveness to song, possibly leading to more territorial conflict in urban areas.

Pinched flow fractionation of microbubbles for ultrasound contrast agent enrichment

NASA Astrophysics Data System (ADS)

Versluis, Michel; Kok, Maarten; Segers, Tim

2014-11-01

An ultrasound contrast agent (UCA) suspension contains a wide size distribution of encapsulated microbubbles (typically 1-10 μm in diameter) that resonate to the driving ultrasound field by the intrinsic relationship between bubble size and ultrasound frequency. Medical transducers, however, operate in a narrow frequency range, which severely limits the number of bubbles that contribute to the echo signal. Thus, the sensitivity can be improved by narrowing down the size distribution of the bubble suspension. Here, we present a novel, low-cost, lab-on-a-chip method for the sorting of contrast microbubbles by size, based on a microfluidic separation technique known as pinched flow fractionation (PFF). We show by experimental and numerical investigation that the inclusion of particle rotation is essential for an accurate physical description of the sorting behavior of the larger bubbles. Successful sorting of a bubble suspension with a narrow size distribution (3.0 +/- 0.6 μm) has been achieved with a PFF microdevice. This sorting technique can be easily parallelized, and may lead to a significant improvement in the sensitivity of contrast-enhanced medical ultrasound. This work is supported by NanoNextNL, a micro and nanotechnology consortium of the Government of the Netherlands and 130 partners.

Generation of narrow energy spread ion beams via collisionless shock waves using ultra-intense 1 um wavelength laser systems

NASA Astrophysics Data System (ADS)

Albert, Felicie; Pak, A.; Kerr, S.; Lemos, N.; Link, A.; Patel, P.; Pollock, B. B.; Haberberger, D.; Froula, D.; Gauthier, M.; Glenzer, S. H.; Longman, A.; Manzoor, L.; Fedosejevs, R.; Tochitsky, S.; Joshi, C.; Fiuza, F.

2017-10-01

In this work, we report on electrostatic collisionless shock wave acceleration experiments that produced proton beams with peak energies between 10-17.5 MeV, with narrow energy spreads between Δ E / E of 10-20%, and with a total number of protons in these peaks of 1e7-1e8. These beams of ions were created by driving an electrostatic collisionless shock wave in a tailored near critical density plasma target using the ultra-intense ps duration Titan laser that operates at a wavelength of 1 um. The near critical density target was produced through the ablation of an initially 0.5 um thick Mylar foil with a separate low intensity laser. A narrow energy spread distribution of carbon / oxygen ions with a similar velocity to the accelerated proton distribution, consistent with the reflection and acceleration of ions from an electrostatic field, was also observed. This work was supported by Lawrence Livermore National Laboratory's Laboratory Directed Research and Development program under project 15-LW-095, and the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA2734.

The string-junction picture of multiquark states: an update

NASA Astrophysics Data System (ADS)

Rossi, G. C.; Veneziano, G.

2016-06-01

We recall and update, both theoretically and phenomenologically, our (nearly) forty-years-old proposal of a string-junction as a necessary complement to the conventional classification of hadrons based just on their quark-antiquark constituents. In that proposal single (though in general metastable) hadronic states are associated with "irreducible" gauge-invariant operators consisting of Wilson lines (visualized as strings of color flux tubes) that may either end on a quark or an antiquark, or annihilate in triplets at a junction J or an anti-junction overline{J} . For the junction-free sector (ordinary qoverline{q} mesons and glueballs) the picture is supported by large- N (number of colors) considerations as well as by a lattice strong-coupling expansion. Both imply the famous OZI rule suppressing quark-antiquark annihilation diagrams. For hadrons with J and/or overline{J} constituents the same expansions support our proposal, including its generalization of the OZI rule to the suppression of J-overline{J} annihilation diagrams. Such a rule implies that hadrons with junctions are "mesophobic" and thus unusually narrow if they are below threshold for decaying into as many baryons as their total number of junctions (two for a tetraquark, three for a pentaquark). Experimental support for our claim, based on the observation that narrow multiquark states typically lie below (well above) the relevant baryonic (mesonic) thresholds, will be presented.

Transformation of Marine Corps Artillery in Support of the 2015 Expeditionary Force

DTIC Science & Technology

2008-04-30

artillery electronics maintenance, and meterological sections in support ofsubordinate elements. On order, the Regiment assumes the primary civil...3rd order capability), engineer, counterbattery radar, artillery electronics maintenance, and meterological sections in support ofsubordinate elements...www.tecom.usmc.mil. (accessed December 15,2007). Training and Education Command. MOS Roadmap: 0847 - Field Artillery Meterological Crew Member. Quantico

Finite Ground Coplanar (FGC) Waveguide: Characteristics and Advantages Evaluated for Radiofrequency and Wireless Communication Circuits

NASA Technical Reports Server (NTRS)

Ponchak, George E.

1999-01-01

Researchers in NASA Lewis Research Center s Electron Device Technology Branch are developing transmission lines for radiofrequency and wireless circuits that are more efficient, smaller, and make lower cost circuits possible. Traditionally, radiofrequency and wireless circuits have employed a microstrip or coplanar waveguide to interconnect the various electrical elements that comprise a circuit. Although a coplanar waveguide (CPW) is widely viewed as better than a microstrip for most applications, it too has problems. To solve these problems, NASA Lewis and the University of Michigan developed a new version of a coplanar waveguide with electrically narrow ground planes. Through extensive numerical modeling and experimental measurements, we have characterized the propagation constant of the FGC waveguide, the lumped and distributed circuit elements integrated in the FGC waveguide, and the coupling between parallel transmission lines. Although the attenuation per unit length is higher for the FGC waveguide because of higher conductor loss, the attenuation is comparable when the ground plane width is twice the center conductor width as shown in the following graph. An upper limit to the line width is derived from observations that when the total line width is greater than ld/2, spurious resonances due to the parallel plate waveguide mode are established. Thus, the ground plane width must be less than ld/4 where ld is the wavelength in the dielectric. Since the center conductor width S is typically less than l/10 to maintain good transverse electromagnetic mode characteristics, it follows that a ground plane width of B = 2S would also be electrically narrow. Thus, we can now treat the ground strips of the FGC waveguide the same way that the center conductor is treated.

Microstructural and hardness investigations on a dissimilar metal weld between low alloy steel and Alloy 82 weld metal

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

Chen, Z.R., E-mail: raymix@aliyun.com

The investigation on microstructure and hardness at the fusion boundary (FB) region of a dissimilar metal weld (DMW) between low alloy steel (LAS) A508-III and Alloy 82 weld metal (WM) was carried out. The results indicated that there were two kinds of FBs, martensite FB and sharp FB, with obvious different microstructures, alternately distributed in the same FB. The martensite FB region had a gradual change of elemental concentration across FB, columnar WM grains with high length/width ratios, a thick martensite layer and a wide heat affected zone (HAZ) with large prior austenite grains. By comparison, the sharp FB regionmore » had a relatively sharp change of elemental concentration across the FB, WM grains with low length/width ratios and a narrow HAZ with smaller prior austenite grains. The martensite possessed a K-S orientation relationship with WM grains, while no orientation relationship was found between the HAZ grains and WM grains at the sharp FB. Compared with sharp FB there were much more Σ3 boundaries in the HAZ beside martensite FB. The hardness maximum of the martensite FB was much higher than that of the sharp FB, which was attributed to the martensite layer at the martensite FB. - Highlights: •Martensite and sharp FBs with different microstructures were found in the same FB. •There were high length/width-ratio WM grains and a wide HAZ beside martensite FB. •There were low length/width-ratio WM grains and a narrow HAZ beside sharp FB. •Compared with sharp FB, there were much more Σ3 boundaries in HAZ of martensite FB. •Hardness maximium of martensite FB was much higher than that of sharp FB.« less

Development and Progress in Enabling the Photocatalyst Ti02 Visible-Light-Active

NASA Technical Reports Server (NTRS)

Levine, Lanfang H.; Coutts, Janelle L.; Clausen, Christian A.

2011-01-01

Photocatalytic oxidation (PCO) of organic contaminants is a promising air and water quality management approach which offers energy and cost savings compared to thermal catalytic oxidation (TCO). The most widely used photocatalyst, anatase TiO2, has a wide band gap (3.2 eV) and is activated by UV photons. Since solar radiation consists of less than 4% UV, but contains 45% visible light, catalysts capable of utilizing these visible photons need to be developed to make peo approaches more efficient, economical, and safe. Researchers have attempted various approaches to enable TiO2 to be visible-light-active with varied degrees of success'. Strategies attempted thus far fall into three categories based on their electrochemical' mechanisms: 1) narrowing the band gap of TiO2 by implantation of transition metal elements or nonmetal elements such as N, S, and C, 2) modifying electron-transfer processes during PCO by adsorbing sensitizing dyes, and 3) employing light-induced interfacial electron transfer in the heteronanojunction systems consisting of narrow band gap semiconductors represented by metal sulfides and TiO2. There are diverse technical approaches to implement each of these strategies. This paper presents a review of these approaches and results of the photocatalytic activity and photonic efficiency of the end .products under visible light. Although resulting visible-light-active (VLA) photocatalysts show promise, there is often no comparison with unmodified TiO2 under UV. In a limited number of studies where such comparison was provided, the UV-induced catalytic activity of bare TiO2 is much greater than the visible-light-induced catalytic activity of the VLA catalyst. Furthermore, VLA-catalysts have much lower quantum efficiency compared to the approx.50% quantum efficiency of UV-catalysts. This stresses the need for continuing research in this area.

Ternary arsenides ATt{sub 3}As{sub 3} (A=K, Rb; Tt=Ge, Sn) with layered structures

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

Khatun, Mansura; Stoyko, Stanislav S.; Mar, Arthur, E-mail: arthur.mar@ualberta.ca

2016-06-15

The four ternary arsenides ATt{sub 3}As{sub 3} (A=K, Rb; Tt=Ge, Sn) were obtained by reaction of the elements at 600–650 °C. They adopt an orthorhombic structure (space group Pnma, Z=4, with cell parameters ranging from a=9.9931(11) Å, b=3.7664(4) Å, c=18.607(2) Å for KGe{sub 3}As{sub 3} to a=10.3211(11) Å, b=4.0917(4) Å, c=19.570(2) Å for RbSn{sub 3}As{sub 3}) containing corrugated [Tt{sub 3}As{sub 3}] layers built from Tt-centred trigonal pyramids and tetrahedra forming five-membered rings decorated with As handles. They can be considered to be Zintl phases with Tt atoms in +4, +3, and +1 oxidation states. Band structure calculations predict that thesemore » compounds are semiconductors with narrow band gaps (0.71 eV in KGe{sub 3}As{sub 3}, 0.50 eV in KSn{sub 3}As{sub 3}). - Graphical abstract: Ternary arsenides ATt{sub 3}As{sub 3} (A=K, Rb; Tt=Ge, Sn) contain corrugated layers with Tt atoms in three different oxidation states and are narrow band gap semiconductors. Display Omitted - Highlights: • ATt{sub 3}As{sub 3} (A=K, Rb; Tt=Ge, Sn) contains Tt atoms in three oxidation states. • The structure differs from NaGe{sub 3}P{sub 3} in terms of layer stacking arrangement. • The compounds are predicted to be narrow band gap semiconductors.« less

IUE Spectra and photoionization models of the Seyfert 2 glaxies NGC 7674 and I Zw 92

NASA Technical Reports Server (NTRS)

Kraemer, Steven B.; Wu, Chi-Chao; Crenshaw, D. Michael; Harrington, J. Patrick

1994-01-01

The physical conditions in the narrow-line regions of two Seyfert 2 galaxies, NGC 7674 and I Zw 92, are examined using IUE spectra, published optical spectra and multifrequency observations, and photoionization models. For each Seyfert galaxy, the emission-line fluxes were dereddened using the He II lambda(1640)/lambda(4686) ratio. Photoionization models were calculated using a power-law index determined from the He II lambda(4686)/H-beta ratio; the index is very similar to that obtained from a fit to the observed multifrequency continuum from the infrared to the X-rays. The models were calculated in a way that minimized the number of assumptions, and given the uncertainties in the reddening corrections, the calculated ratios match nearly all of the dereddened ratios successfully. a multicomponent model (three components with different densities and ionization parameters) was required to fit the spectrum of I Zw 92, whereas a single component was sufficient for NGC 7674. The CNO abundances are close to solar, although a reduced abundance of up to one-third solar for one or more of the heavy elements is possible. In contrast to a previous study of Mrk 3, dust inside the narrow-line region (NLR) louds was not required to fit the spectra of these two Seyfert galaxies, although the emission lines experience considerable reddening from external dust. Higher signal-to-noise spectra in the UV are essential for placing further restrictions on the reddening and physical conditions in the narrow-line regions of Seyfert galaxies.

A tactile sensing element based on a hetero-core optical fiber for force measurement and texture detection

NASA Astrophysics Data System (ADS)

Yamazaki, Hiroshi; Koyama, Yuya; Watanabe, Kazuhiro

2014-05-01

Tactile sensing technology can measure a given property of an object through physical contact between a sensing element and the object. Various tactile sensing techniques have been developed for several applications such as intelligent robots, tactile interface, medical support and nursing care support. A desirable tactile sensing element for supporting human daily life can be embedded in the soft material with high sensitivity and accuracy in order to prevent from damaging to human or object physically. This report describes a new tactile sensing element. Hetero-core optical fibers have high sensitivity of macro-bending at local sensor portion and temperature independency, including advantages of optical fiber itself; thin size, light weight, flexible transmission line, and immunity to electro-magnetic interference. The proposed tactile sensing element could detect textures of touched objects through the optical loss caused by the force applied to the sensing element. The characteristics of the sensing element have been evaluated, in which the sensing element has the monotonic and non-linear sensitivity against the normal force ranged from 0 to 5 N with lower accuracy than 0.25 dB. Additionally, texture detection have been successfully demonstrated in which small surface figures of 0.1 mm in height were detected with spatial resolution of 0.4 mm.

Elemental selenium at nano size (Nano-Se) as a potential chemopreventive agent with reduced risk of selenium toxicity: comparison with se-methylselenocysteine in mice.

PubMed

Zhang, Jinsong; Wang, Xufang; Xu, Tongwen

2008-01-01

Selenium (Se) is an essential trace element with a narrow margin between beneficial and toxic effects. As a promising chemopreventive agent, its use requires consumption over the long term, so the toxicity of Se is always a crucial concern. Based on clinical findings and recent studies in selenoprotein gene-modified mice, it is likely that the antioxidant function of one or more selenoproteins is responsible for the chemopreventive effect of Se. Furthermore, upregulation of phase 2 enzymes by Se has been implicated as a possible chemopreventive mechanism at supranutritional dietary levels. Se-methylselenocysteine (SeMSC), a naturally occurring organic Se product, is considered as one of the most effective chemopreventive selenocompounds. The present study revealed that, as compared with SeMSC, elemental Se at nano size (Nano-Se) possessed equal efficacy in increasing the activities of glutathione peroxidase, thioredoxin reductase, and glutathione S-transferase, but had much lower toxicity as indicated by median lethal dose, acute liver injury, survival rate, and short-term toxicity. Our results suggest that Nano-Se can serve as a potential chemopreventive agent with reduced risk of Se toxicity.

Photoabsorption Study of Bacillus megaterium, DNA and Related Biological Materials in the Phosphorus K-edge Region

NASA Technical Reports Server (NTRS)

Frigo, Sean P.; McNulty, Ian; Richmond, Robert C.; Ehret, Charles F.

2002-01-01

We have measured the x-ray transmission spectra of several biologically related samples in the phosphorus K-edge absorption region. These include elemental red phosphorus, hydrated sodium phosphate (Na3PO4.12H2O), deoxyribonucleic acid (DNA), adenosinetriphosphate (ATP), diolylphosphatidyl choline (DOPC), and Bacillus megaterium spores. Elemental red phosphorus essentially displays an edge-jump. All other spectra are similar in form and energy position. Each spectrum for these substances is dominated by a narrower, more intense first peak and a broader but less intense second peak. The corresponding K-edge absorption thresholds are shifted towards higher energy relative to that for elemental red phosphorus, as expected for increasing degrees of phosphorus oxidation. The B. megaterium spectrum has aspects common to both the phosphate and DNA spectra and is therefore interpreted as a composite of spectra arising from DNA/RNA and phosphates within the spore. The B. megaterium spore spectrum provides needed information for resonant radiation damage studies in the phosphorus K-edge absorption region by identifying candidate photoexcitations. In addition,the absorption spectra will be useful in macromolecular crystallography studies employing anomalous dispersion effects at the phosphorus K-edge.

Evaluation of a MMW active through-the-wall surveillance system

NASA Astrophysics Data System (ADS)

Currie, Nicholas C.; Stiefvater, Kenneth

2002-08-01

This paper discusses the TWS data collected with a state-of- the-art 100 GHz radar imager developed for law enforcement use by Millivision, PPC. The system collects a cube of data consisting of 16 azimuth elements by 16 elevation elements by 256 range elements. The cube represents 11 degrees by 11 degrees by 25 m of coverage. The relatively narrow field-of- view (fov) was extended by physically moving the antenna in 11 degree segments and collecting data which is stitched together into larger images, e.g. a 3X3 stitched image represents 33 degrees by 33 degrees by 26 m of coverage. Unfortunately, this stitching process required up to 5 minutes to collect a single (3X3) stitched image. Thus, motion had to be simulated. The paper will discuss the phenomenology of the MMW radar return from various objects including walls, wall-corners, desks and other furniture, and persons simulating walking. Successive frames from a simulated move of a man and woman walking will be presented, and the actual movie shown at the presentation. Comments will be offered as to the practicality of active MMW imaging for TWS application.

Discrete Element Simulations of Density-Driven Volcanic Deformation: Applications to Martian Caldera Complexes

NASA Astrophysics Data System (ADS)

Zivney, L. L.; Morgan, J. K.; McGovern, P. J.

2009-12-01

We have carried out 2-D numerical simulations using the discrete element method (DEM) to investigate density-driven deformation in Martian volcanic edifices. Our initial simulations demonstrated that gravitationally-driven settling of a dense, ductile cumulate body within a volcano causes enhanced lateral spreading of the edifice flanks, influencing the overall volcano morphology and generating pronounced summit subsidence. Here, we explore the effects of cumulate bodies and their geometries on the generation of summit calderas, to gain insight into the origin of Martian caldera complexes, in particular the Olympus Mons and Arsia Mons calderas. The Olympus Mons caldera, roughly 80 km in diameter, is composed of several small over-lapping craters with steep walls, thought to be produced by episodic collapse events of multiple shallow magma chambers. The Arsia Mons caldera spans ~130 km across and displays one prominent crater with gently sloping margins, possibly reflecting the collapse of a single magma chamber. Although the depth of the magma chamber is debated, its lateral width is thought to approximate the diameter of the caldera. Our models indicate that cumulate bodies located at shallow depths of <10 km below the edifice surface produce caldera complexes on the order of 80-100 km in width, with increasing cumulate widths producing widening calderas. Narrow cumulate bodies with densities near 4000 kg/m3 produce the deepest calderas (up to ~8 km deep). We conclude that the generation of large Arsia-type calderas may be adequately modeled by the presence of a wide cumulate body found at shallow depths beneath the summit. Although we do not model the multiple magma chamber systems thought to exist beneath the Olympus Mons summit, the closely spaced craters and the small size of the caldera relative to the size of the volcano (~13% of the edifice) suggests that the cumulate body would be narrow; our simulations of a single narrow cumulate body are capable of generating summit subsidence that is similar in dimension to the Olympus Mons caldera. Our findings suggest that cumulate spreading may play a primary role in the long-term development of caldera geometry, although the collapse of magma reservoirs (not modeled here) may cause important short-term changes in caldera structure.

The merging dwarf galaxy UM 448: chemodynamics of the ionized gas from VLT integral field spectroscopy

NASA Astrophysics Data System (ADS)

James, B. L.; Tsamis, Y. G.; Barlow, M. J.; Walsh, J. R.; Westmoquette, M. S.

2013-01-01

Using Very Large Telescope/Fibre Large Array Multi Element Spectrograph optical integral field unit observations, we present a detailed study of UM 448, a nearby blue compact galaxy (BCG) previously reported to have an anomalously high N/O abundance ratio. New Technology Telescope/Superb-Seeing Imager images reveal a morphology suggestive of a merger of two systems of contrasting colour, whilst our Hα emission maps resolve UM 448 into three separate regions that do not coincide with the stellar continuum peaks. UM 448 exhibits complex emission line profiles, with most lines consisting of a narrow [full width at half-maximum (FWHM) ≲ 100 km s-1], central component, an underlying broad component (FWHM ˜ 150-300 km s-1) and a third, narrow blueshifted component. Radial velocity maps of all three components show signs of solid body rotation across UM 448, with a projected rotation axis that correlates with the continuum morphology of the galaxy. A spatially resolved, chemodynamical analysis, based on the [O iii] λλ4363, 4959, [N ii] λ6584, [S ii] λλ6716, 6731 and [Ne iii] λ3868 line maps, is presented. Whilst the eastern tail of UM 448 has electron temperatures (Te) that are typical of BCGs, we find a region within the main body of the galaxy where the narrow and broad [O iii] λ4363 line components trace temperatures differing by 5000 K and oxygen abundances differing by 0.4 dex. We measure spatially resolved and integrated ionic and elemental abundances for O, N, S and Ne throughout UM 448, and find that they do not agree, possibly due the flux weighting of Te from the integrated spectrum. This has significant implications for abundances derived from long-slit and integrated spectra of star-forming galaxies in the nearby and distant universe. A region of enhanced N/O ratio is indeed found, extended over a ˜0.6 kpc2 region within the main body of the galaxy. Contrary to previous studies, however, we do not find evidence for a large Wolf-Rayet (WR) population, and conclude that WR stars alone cannot be responsible for producing the observed N/O excess. Instead, the location and disturbed morphology of the N-enriched region suggest that interaction-induced inflow of metal-poor gas may be responsible.

Finite Element Analysis of Tube Hydroforming in Non-Symmetrical Dies

NASA Astrophysics Data System (ADS)

Nulkar, Abhishek V.; Gu, Randy; Murty, Pilaka

2011-08-01

Tube hydroforming has been studied intensively using commercial finite element programs. A great deal of the investigations dealt with models with symmetric cross-sections. It is known that additional constraints due to symmetry may be imposed on the model so that it is properly supported. For a non-symmetric model, these constraints become invalid and the model does not have sufficient support resulting in a singular finite element system. Majority of commercial codes have a limited capability in solving models with insufficient supports. Recently, new algorithms using penalty variable and air-like contact element (ALCE) have been developed to solve positive semi-definite finite element systems such as those in contact mechanics. In this study the ALCE algorithm is first validated by comparing its result against a commercial code using a symmetric model in which a circular tube is formed to polygonal dies with symmetric shapes. Then, the study investigates the accuracy and efficiency of using ALCE in analyzing hydroforming of tubes with various cross-sections in non-symmetrical dies in 2-D finite element settings.

Computer-aided diagnosis of colorectal polyp histology by using a real-time image recognition system and narrow-band imaging magnifying colonoscopy.

PubMed

Kominami, Yoko; Yoshida, Shigeto; Tanaka, Shinji; Sanomura, Yoji; Hirakawa, Tsubasa; Raytchev, Bisser; Tamaki, Toru; Koide, Tetsusi; Kaneda, Kazufumi; Chayama, Kazuaki

2016-03-01

It is necessary to establish cost-effective examinations and treatments for diminutive colorectal tumors that consider the treatment risk and surveillance interval after treatment. The Preservation and Incorporation of Valuable Endoscopic Innovations (PIVI) committee of the American Society for Gastrointestinal Endoscopy published a statement recommending the establishment of endoscopic techniques that practice the resect and discard strategy. The aims of this study were to evaluate whether our newly developed real-time image recognition system can predict histologic diagnoses of colorectal lesions depicted on narrow-band imaging and to satisfy some problems with the PIVI recommendations. We enrolled 41 patients who had undergone endoscopic resection of 118 colorectal lesions (45 nonneoplastic lesions and 73 neoplastic lesions). We compared the results of real-time image recognition system analysis with that of narrow-band imaging diagnosis and evaluated the correlation between image analysis and the pathological results. Concordance between the endoscopic diagnosis and diagnosis by a real-time image recognition system with a support vector machine output value was 97.5% (115/118). Accuracy between the histologic findings of diminutive colorectal lesions (polyps) and diagnosis by a real-time image recognition system with a support vector machine output value was 93.2% (sensitivity, 93.0%; specificity, 93.3%; positive predictive value (PPV), 93.0%; and negative predictive value, 93.3%). Although further investigation is necessary to establish our computer-aided diagnosis system, this real-time image recognition system may satisfy the PIVI recommendations and be useful for predicting the histology of colorectal tumors. Copyright © 2016 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.

Age-related modifications in steering behaviour: effects of base-of-support constraints at the turn point.

PubMed

Paquette, Maxime R; Fuller, Jason R; Adkin, Allan L; Vallis, Lori Ann

2008-09-01

This study investigated the effects of altering the base of support (BOS) at the turn point on anticipatory locomotor adjustments during voluntary changes in travel direction in healthy young and older adults. Participants were required to walk at their preferred pace along a 3-m straight travel path and continue to walk straight ahead or turn 40 degrees to the left or right for an additional 2-m. The starting foot and occasionally the gait starting point were adjusted so that participants had to execute the turn using a cross-over step with a narrow BOS or a lead-out step with a wide BOS. Spatial and temporal gait variables, magnitudes of angular segmental movement, and timing and sequencing of body segment reorientation were similar despite executing the turn with a narrow or wide BOS. A narrow BOS during turning generated an increased step width in the step prior to the turn for both young and older adults. Age-related changes when turning included reduced step velocity and step length for older compared to young adults. Age-related changes in the timing and sequencing of body segment reorientation prior to the turn point were also observed. A reduction in walking speed and an increase in step width just prior to the turn, combined with a delay in motion of the center of mass suggests that older adults used a more cautious combined foot placement and hip strategy to execute changes in travel direction compared to young adults. The results of this study provide insight into mobility constraints during a common locomotor task in older adults.

Ringing in an HNBody Upgrade

NASA Astrophysics Data System (ADS)

Rimlinger, Thomas; Hamilton, Douglas; Hahn, Joseph M.

2017-06-01

We are in the process of developing a useful extension to the N-body integrator HNBody (Rauch & Hamilton 2002), enabling it to simulate a viscous, self-gravitating ring orbiting an oblate body. Our algorithm follows that used in the symplectic integrator epi_int (Hahn & Spitale 2013), in which the ring is simulated as many (~100) interacting, elliptic, confocal streamlines. This idea was first introduced in an analytic context by Goldreich & Tremaine (1979) and enabled rapid progress in the theory of ring evolution; since then, such discretization has been standard in the literature. While we adopt epi_int’s streamline formalism, we nevertheless improve upon its design in several ways. Epi_int uses epicyclic elements in its drift step; approximating these elements introduces small, systematic errors that build up with time. We sidestep this problem by instead using the more traditional Keplerian osculating elements. In addition, epi_int uses several particles per wire to effectively calculate the inter-gravitational forces everywhere along each streamline. We replicate this ability but can often gain a speed boost by using a single tracer particle per streamline; while this restricts us to simulating rings dominated by the m = 1 mode, this is typical of most observed narrow eccentric ringlets. We have also extended epi_int’s two dimensional algorithm into 3D. Finally, whereas epi_int is written in IDL, HNBody is written in C, which yields considerably faster integrations.Braga-Ribas et al. (2014) reported a set of narrow rings orbiting the Centaur Chariklo, but neither their investigation nor that of Pan & Wu (2016) yielded a satisfactory origin and evolution scenario. Eschewing the assumption that such rings must be short-lived, we instead argue (as in Rimlinger et al. 2016) that sufficiently eccentric rings can self-confine for hundreds of millions of years while circularizing. In this case, Chariklo may have formed rings as a KBO. We are working towards demonstrating both the feasibility of this theory and the utility of the HNBody extension by using it to simulate such a ring around Chariklo.

Redesigning Systems of School Accountability: A Multiple Measures Approach to Accountability and Support

ERIC Educational Resources Information Center

Bae, Soung

2018-01-01

The challenges facing our children in the 21st century are rapidly changing. As a result, schools bear a greater responsibility to prepare students for college, career, and life and must be held accountable for more than just testing and reporting on a narrow set of outcomes aimed at minimum levels of competency. Thus, scholars, educators, and…

Stable wafer-carrier system

DOEpatents

Rozenzon, Yan; Trujillo, Robert T; Beese, Steven C

2013-10-22

One embodiment of the present invention provides a wafer-carrier system used in a deposition chamber for carrying wafers. The wafer-carrier system includes a base susceptor and a top susceptor nested inside the base susceptor with its wafer-mounting side facing the base susceptor's wafer-mounting side, thereby forming a substantially enclosed narrow channel. The base susceptor provides an upward support to the top susceptor.

Civic Engagement and the Arts and Humanities: A UK Perspective

ERIC Educational Resources Information Center

Gallagher, Tony

2015-01-01

Higher education in the UK is in a state of flux and this is having particular impact on the humanities. On the one hand, the pressure to support a STEM agenda is seen by some as forcing higher education down a narrow economic agenda, while government requirements for assessing the social and economic impact of research have raised concerns about…

5 CFR Appendix A to Subpart E of... - Schedule of Environmental Differentials Paid for Exposure to Various Degrees of Hazards, Physical...

Code of Federal Regulations, 2011 CFR

2011-01-01

.... 1, 1970. Examples —Working with, or in close proximity to operations involved in research, in... adequate (for example, working from a swinging stage, boatswain chair, a similar support); or (3) If... employees; such as the following: July 1, 1972. Examples: —Working on cliffs, narrow ledges, or steep...

Picture That: Supporting Sexuality Educators in Narrowing the Knowledge/Practice Gap

ERIC Educational Resources Information Center

Beyers, Christa

2012-01-01

Teaching about sex and relationships is one of the greatest challenges in not only the combating of HIV and AIDS, but also in preparing the youth for responsible sexual behaviour. Although it seems as if teachers to some extent do feel comfortable with the teaching of sexuality education at school, the question however remains as to whether youth…

Mental Health, Well-Being, and Learning: Supporting Our Students in Times of Need

ERIC Educational Resources Information Center

Schwitzer, Alan M.; Vaughn, John A.

2017-01-01

Everybody on campus is responsible for recognizing and responding to students in crisis. Sometimes the difficulty is knowing when to intervene. Being alert to students' mental health and wellness needs is an essential part of work life on today's campuses--even when it means stepping out of one's own narrow professional roles or risking leaving…

Factors affecting songbird nest survival in riparian forests in a Midwestern agricultural landscape

Treesearch

Rebecca G. Peak; Frank R. Thompson; Terry L. Shaffer

2004-01-01

We investigated factors affecting nest success of songbirds in riparian forest and buffers in northeastern Missouri. We used an information-theoretic approach to determine support for hypotheses concerning effects of nest-site, habitat-patch, edge, and temporal factors on nest success of songbirds in three narrow (55-95 m) and three wide (400-530 m) riparian forests...

Examining the Relationship between Secondary Mathematics Teachers' Self-Efficacy, Attitudes, and Use of Technology to Support Communication and Mathematics Literacy

ERIC Educational Resources Information Center

Letwinsky, Karim Medico

2017-01-01

The rich language surrounding mathematical concepts often is reduced in many classrooms to a narrow process of memorizing isolated procedures with little context. This approach has proven to be detrimental to students' ability to understand mathematics at deeper levels and remain engaged with this content. The current generation of students values…

Consolidation of Federal Aid Programs for Education: A Case for Block Grant Funding.

ERIC Educational Resources Information Center

Main, Robert G.

The need for a new approach to federal support of education by reducing the number of narrow categorical aid programs is developed through a case study of the 1976 Ford Administration proposal for a consolidated block grant of 24 separate authorities. The merits of block grant funding are examined both in terms of the administration-sponsored bill…

A Forest of Sub-1.5-nm-wide Single-Walled Carbon Nanotubes over an Engineered Alumina Support

NASA Astrophysics Data System (ADS)

Yang, Ning; Li, Meng; Patscheider, Jörg; Youn, Seul Ki; Park, Hyung Gyu

2017-04-01

A precise control of the dimension of carbon nanotubes (CNTs) in their vertical array could enable many promising applications in various fields. Here, we demonstrate the growth of vertically aligned, single-walled CNTs (VA-SWCNTs) with diameters in the sub-1.5-nm range (0.98 ± 0.24 nm), by engineering a catalyst support layer of alumina via thermal annealing followed by ion beam treatment. We find out that the ion beam bombardment on the alumina allows the growth of ultra-narrow nanotubes, whereas the thermal annealing promotes the vertical alignment at the expense of enlarged diameters; in an optimal combination, these two effects can cooperate to produce the ultra-narrow VA-SWCNTs. According to micro- and spectroscopic characterizations, ion beam bombardment amorphizes the alumina surface to increase the porosity, defects, and oxygen-laden functional groups on it to inhibit Ostwald ripening of catalytic Fe nanoparticles effectively, while thermal annealing can densify bulk alumina to prevent subsurface diffusion of the catalyst particles. Our findings contribute to the current efforts of precise diameter control of VA-SWCNTs, essential for applications such as membranes and energy storage devices.

Low-dimensional organization of angular momentum during walking on a narrow beam.

PubMed

Chiovetto, Enrico; Huber, Meghan E; Sternad, Dagmar; Giese, Martin A

2018-01-08

Walking on a beam is a challenging motor skill that requires the regulation of upright balance and stability. The difficulty in beam walking results from the reduced base of support compared to that afforded by flat ground. One strategy to maintain stability and hence avoid falling off the beam is to rotate the limb segments to control the body's angular momentum. The aim of this study was to examine the coordination of the angular momentum variations during beam walking. We recorded movement kinematics of participants walking on a narrow beam and computed the angular momentum contributions of the body segments with respect to three different axes. Results showed that, despite considerable variability in the movement kinematics, the angular momentum was characterized by a low-dimensional organization based on a small number of segmental coordination patterns. When the angular momentum was computed with respect to the beam axis, the largest fraction of its variation was accounted for by the trunk segment. This simple organization was robust and invariant across all participants. These findings support the hypothesis that control strategies for complex balancing tasks might be easier to understand by investigating angular momentum instead of the segmental kinematics.

The Case for General Relativistic Effects in the Fe K(alpha) Profile of an Active Galaxy

NASA Technical Reports Server (NTRS)

Turner, T. J.; Mushotzky, R.; Yaqoob, T.; George, I. M.; Snowden, S. L.; Netzer, H.; Kraemer, S. B.; Nandra, K.; Chelouche, D.; White, Nicholas E. (Technical Monitor)

2002-01-01

We present results from a simultaneous Chandra HETG (High Energy Transmission Grating) and XMM (X-ray Multi-mirror Mission)-Newton observation of NGC 3516. We find evidence for several narrow components of Fe K(alpha) along with a broad line. We consider the possibility that the lines arise in a blob of material ejected from the nucleus with velocity of approximately 0.25c. We also consider an origin in a neutral accretion disk, suffering enhanced illumination at 35 and 175 R(sub g), perhaps due to magnetic reconnection. The presence of these narrow features indicates there is no Comptonizing region along the line-of-sight to the nucleus. This in turn is compelling support for the hypothesis that broad Fe K(alpha) components are, in general, produced by strong gravity.

Cultivating the field of psychology. Psychological journals at the turn of the century and beyond.

PubMed

Johnson, D F

2000-10-01

Prominent psychologists, including G. Stanley Hall, James Mark Baldwin, and James McKeen Cattell, cultivated the field of psychological publishing with privately owned and managed journals. Hall's journals, including the American Journal of Psychology and Pedagogical Seminary, reflected his view of psychology as the empirical study of human nature and his support for applied psychology. Baldwin and Cattell's periodicals, including Psychological Review and Psychological Monographs, reflected a narrower scientific and academic view of psychology. Baldwin and Cattell were more successful editors than Hall and strategically linked their journals to the American Psychological Association (APA). The Psychological Review journals were purchased by APA in 1925. The narrower vision represented in these journals may have contributed to applied psychologists' dissatisfaction with APA during the late 1920s and early 1930s.

Radicals mediated magnetism in Ar plasma treated high-density polyethylene

NASA Astrophysics Data System (ADS)

Orendáč, M.; Čižmár, E.; Kažiková, V.; Orendáčová, A.; Řezníčková, A.; Kolská, Z.; Švorčík, V.

2018-05-01

Electron-spin resonance of high-density polyethylene treated by Ar plasma at 300 K was performed in X-band at temperatures from 2.1 K to 290 K. The observed spectra suggest presence of allyl radicals, whereas the central peak may be attributed to polyenyl radicals or dangled bonds. Pronounced narrowing of the resonance line observed above glassy temperature of polyethylene may be ascribed to thermally activated motional effect with the activation energy Ea /kB = 160 K. The absence of strong exchange interactions is suggested by negligible exchange narrowing found at 2.1 K. The suggestion is supported by the analysis of the temperature dependence of the intensity at low temperatures, which is explicable assuming the coexistence of non-interacting radicals and S = 1/2 dimers with a distribution of antiferromagnetic couplings varying from 2 K to nominally 25 K.

Predation by killer whales (Orcinus orca) and the evolution of whistle loss and narrow-band high frequency clicks in odontocetes.

PubMed

Morisaka, T; Connor, R C

2007-07-01

A disparate selection of toothed whales (Odontoceti) share striking features of their acoustic repertoires including the absence of whistles and high frequency but weak (low peak-to-peak source level) clicks that have a relatively long duration and a narrow bandwidth. The non-whistling, high frequency click species include members of the family Phocoenidae, members of one genus of delphinids, Cephalorhynchus, the pygmy sperm whale, Kogia breviceps, and apparently the sole member of the family Pontoporiidae. Our review supports the 'acoustic crypsis' hypothesis that killer whale predation risk was the primary selective factor favouring an echolocation and communication system in cephalorhynchids, phocoenids and possibly Pontoporiidae and Kogiidae restricted to sounds that killer whales hear poorly or not at all (< 2 and > 100 kHz).

Electro-statically controllable graphene local heater

NASA Astrophysics Data System (ADS)

Wang, Hui-Shan; Deng, Lian-Wen; Li, Lei; Sun, Qiu-Juan; Xie, Hong; Wang, Hao-Min

2018-03-01

We report on current-induced thermal power investigation of graphene nanostructure for potential local-heating applications. It is found that the efficiency of heating can be greatly improved if graphene is patterned into structures with narrow width and long channel. In a narrow graphene-ribbon, the Joule heating power exhibits an obvious dependence on the back-gate voltage. By monitoring Raman spectra, the temperature of graphene-ribbon can be determined. The temperature of graphene-ribbon is modulated by the electric field effect when the sample is sourced with a relatively high current. Project supported by the National Key R&D Program of China (Grant No. 2017YFF0206106), the Chinese Academy of Sciences (Grant No. XDB04040300), the National Natural Science Foundation of China (Grant No. 51772317), and the Science and Technology Commission of Shanghai Municipality, China (Grant No. 16ZR1442700).

77 FR 48969 - Record of Decision for the U.S. Marine Corps Basing of MV-22 and H-1 Aircraft in Support of III...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-15

... DEPARTMENT OF DEFENSE Department of the Navy Record of Decision for the U.S. Marine Corps Basing of MV-22 and H-1 Aircraft in Support of III Marine Expeditionary Force Elements in Hawaii AGENCY... aircraft) in support of III Marine Expeditionary Force elements in Hawaii. SUPPLEMENTARY INFORMATION: The...

Force Structure: Better Information Needed to Support Air Force A-10 and Other Future Divestment Decisions

DTIC Science & Technology

2016-08-01

estimate should have a standardized structure that breaks costs into discrete elements with sufficient detail to ensure that cost elements are...FORCE STRUCTURE Better Information Needed to Support Air Force A-10 and Other Future Divestment Decisions Report...Accountability Office Highlights of GAO-16-816, a report to congressional committees August 2016 FORCE STRUCTURE Better Information Needed to Support

34. DETAILS AND SECTIONS OF SHIELDING TANK FUEL ELEMENT SUPPORT ...

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

34. DETAILS AND SECTIONS OF SHIELDING TANK FUEL ELEMENT SUPPORT FRAME. F.C. TORKELSON DRAWING NUMBER 842-ARVFS-701-S-4. INEL INDEX CODE NUMBER: 075 0701 60 851 151978. - Idaho National Engineering Laboratory, Advanced Reentry Vehicle Fusing System, Scoville, Butte County, ID

Moment free toroidal magnet

DOEpatents

Bonanos, Peter

1983-01-01

A toroidal magnet for confining a high magnetic field for use in fusion reactor research and nuclear particle detection. The magnet includes a series of conductor elements arranged about and fixed at its small major radius portion to the outer surface of a central cylindrical support each conductor element having a geometry such as to maintain the conductor elements in pure tension when a high current flows therein, and a support assembly which redistributes all or part of the tension which would otherwise arise in the small major radius portion of each coil element to the large major radius portion thereof.

RELATIVE ABUNDANCE MEASUREMENTS IN PLUMES AND INTERPLUMES

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

Guennou, C.; Hahn, M.; Savin, D. W., E-mail: cguennou@iac.es

2015-07-10

We present measurements of relative elemental abundances in plumes and interplumes. Plumes are bright, narrow structures in coronal holes that extend along open magnetic field lines far out into the corona. Previous work has found that in some coronal structures the abundances of elements with a low first ionization potential (FIP) <10 eV are enhanced relative to their photospheric abundances. This coronal-to-photospheric abundance ratio, commonly called the FIP bias, is typically 1 for elements with a high-FIP (>10 eV). We have used Extreme Ultraviolet Imaging Spectrometer observations made on 2007 March 13 and 14 over a ≈24 hr period tomore » characterize abundance variations in plumes and interplumes. To assess their elemental composition, we used a differential emission measure analysis, which accounts for the thermal structure of the observed plasma. We used lines from ions of iron, silicon, and sulfur. From these we estimated the ratio of the iron and silicon FIP bias relative to that for sulfur. From the results, we have created FIP-bias-ratio maps. We find that the FIP-bias ratio is sometimes higher in plumes than in interplumes and that this enhancement can be time dependent. These results may help to identify whether plumes or interplumes contribute to the fast solar wind observed in situ and may also provide constraints on the formation and heating mechanisms of plumes.« less

Photon interaction studies using 241Am g-rays

NASA Astrophysics Data System (ADS)

Ramachandran, N.; Karunakaran Nair, K.; Abdullah, K. K.; Varier, K. M.

2006-09-01

We have carried out some photon interaction measurements using 59.54 keV γ-rays from a ^{241}Am source. These include γ attenuation studies as well as photoelectric absorption studies in various samples. The attenuation studies have been made using leaf and wood samples, samples like sand, sugar etc., which contain particles of varying sizes as well as pellets and aqueous solutions of rare earth compounds. In the case of the leaf and wood samples, we have used the γ-ray attenuation technique for the determination of the water content in fresh and dried samples. The variation of the attenuation coefficient with particle size has been investigated for sand and sugar samples. The attenuation studies as well as the photoelectric studies in the case of rare earth elements have been carried out on samples containing such elements whose K-absorption edge energies lie below and close to the γ-energy used. Suitable compounds of the rare earth elements have been chosen as mixture absorbers in these investigations. A narrow beam good geometry set-up was used for the attenuation measurements. A well-shielded scattering geometry was used for the photoelectric measurements. The mixture rule was invoked to extract the values of the mass attenuation coefficients for the elements from those of the corresponding compounds. The results are consistent with theoretical values derived from the XCOM package.

Isotopic and trace element geochemistry of the Seligdar magnesiocarbonatites (South Yakutia, Russia): Insights regarding the mantle evolution beneath the Aldan-Stanovoy shield

NASA Astrophysics Data System (ADS)

Doroshkevich, Anna G.; Prokopyev, Ilya R.; Izokh, Andrey E.; Klemd, Reiner; Ponomarchuk, Anton V.; Nikolaeva, Irina V.; Vladykin, Nikolay V.

2018-04-01

The Paleoproterozoic Seligdar magnesiocarbonatite intrusion of the Aldan-Stanovoy shield in Russia underwent extensive postmagmatic hydrothermal alteration and metamorphic events. This study comprises new isotopic (Sr, Nd, C and O) data, whole-rock major and trace element compositions and trace element characteristics of the major minerals to gain a better understanding of the source and the formation process of the carbonatites. The Seligdar carbonatites have high concentrations of P2O5 (up to 18 wt%) and low concentrations of Na, K, Sr and Ba. The chondrite-normalized REE patterns of these carbonatites display significant enrichments of LREE relative to HREE with an average La/Ybcn ratio of 95. Hydrothermal and metamorphic overprints changed the trace element characteristics of the carbonatites and their minerals. These alteration processes were responsible for Sr loss and the shifting of the Sr isotopic compositions towards more radiogenic values. The altered carbonatites are further characterized by distinct 18O- and 13C-enrichments compared to the primary igneous carbonatites. The alteration most likely resulted from both the percolation of crustal-derived hydrothermal fluids and subsequent metamorphic processes accompanied by interaction with limestone-derived CO2. The narrow range of negative εNd(T) values indicates that the Seligdar carbonatites are dominated by a homogenous enriched mantle source component that was separated from the depleted mantle during the Archean.

Supported inorganic membranes

DOEpatents

Sehgal, Rakesh; Brinker, Charles Jeffrey

1998-01-01

Supported inorganic membranes capable of molecular sieving, and methods for their production, are provided. The subject membranes exhibit high flux and high selectivity. The subject membranes are substantially defect free and less than about 100 nm thick. The pores of the subject membranes have an average critical pore radius of less than about 5 .ANG., and have a narrow pore size distribution. The subject membranes are prepared by coating a porous substrate with a polymeric sol, preferably under conditions of low relative pressure of the liquid constituents of the sol. The coated substrate is dried and calcined to produce the subject supported membrane. Also provided are methods of derivatizing the surface of supported inorganic membranes with metal alkoxides. The subject membranes find use in a variety of applications, such as the separation of constituents of gaseous streams, as catalysts and catalyst supports, and the like.

SDMS: A scientific data management system

NASA Technical Reports Server (NTRS)

Massena, W. A.

1978-01-01

SDMS is a data base management system developed specifically to support scientific programming applications. It consists of a data definition program to define the forms of data bases, and FORTRAN-compatible subroutine calls to create and access data within them. Each SDMS data base contains one or more data sets. A data set has the form of a relation. Each column of a data set is defined to be either a key or data element. Key elements must be scalar. Data elements may also be vectors or matrices. The data elements in each row of the relation form an element set. SDMS permits direct storage and retrieval of an element set by specifying the corresponding key element values. To support the scientific environment, SDMS allows the dynamic creation of data bases via subroutine calls. It also allows intermediate or scratch data to be stored in temporary data bases which vanish at job end.

Space Operations Center system analysis. Volume 3, book 2: SOC system definition report, revision A

NASA Technical Reports Server (NTRS)

1982-01-01

The Space Operations Center (SOC) orbital space station program operations are described. A work breakdown structure for the general purpose support equipment, construction and transportation support, and resupply and logistics support systems is given. The basis for the design of each element is presented, and a mass estimate for each element supplied. The SOC build-up operation, construction, flight support, and satellite servicing operations are described. Detailed programmatics and cost analysis are presented.

HIGH TEMPERATURE, HIGH POWER HETEROGENEOUS NUCLEAR REACTOR

DOEpatents

Hammond, R.P.; Wykoff, W.R.; Busey, H.M.

1960-06-14

A heterogeneous nuclear reactor is designed comprising a stationary housing and a rotatable annular core being supported for rotation about a vertical axis in the housing, the core containing a plurality of radial fuel- element supporting channels, the cylindrical empty space along the axis of the core providing a central plenum for the disposal of spent fuel elements, the core cross section outer periphery being vertically gradated in radius one end from the other to provide a coolant duct between the core and the housing, and means for inserting fresh fuel elements in the supporting channels under pressure and while the reactor is in operation.

Linear Mathematical Model for Seam Tracking with an Arc Sensor in P-GMAW Processes

PubMed Central

Liu, Wenji; Li, Liangyu; Hong, Ying; Yue, Jianfeng

2017-01-01

Arc sensors have been used in seam tracking and widely studied since the 80s and commercial arc sensing products for T and V shaped grooves have been developed. However, it is difficult to use these arc sensors in narrow gap welding because the arc stability and sensing accuracy are not satisfactory. Pulse gas melting arc welding (P-GMAW) has been successfully applied in narrow gap welding and all position welding processes, so it is worthwhile to research P-GMAW arc sensing technology. In this paper, we derived a linear mathematical P-GMAW model for arc sensing, and the assumptions for the model are verified through experiments and finite element methods. Finally, the linear characteristics of the mathematical model were investigated. In torch height changing experiments, uphill experiments, and groove angle changing experiments the P-GMAW arc signals all satisfied the linear rules. In addition, the faster the welding speed, the higher the arc signal sensitivities; the smaller the groove angle, the greater the arc sensitivities. The arc signal variation rate needs to be modified according to the welding power, groove angles, and weaving or rotate speed. PMID:28335425

Three-dimensional cavity nanoantennas with resonant-enhanced surface plasmons as dynamic color-tuning reflectors.

PubMed

Fan, J R; Wu, W G; Chen, Z J; Zhu, J; Li, J

2017-03-09

As plasmonic antennas for surface-plasmon-assisted control of optical fields at specific frequencies, metallic nanostructures have recently emerged as crucial optical components for fascinating plasmonic color engineering. Particularly, plasmonic resonant nanocavities can concentrate lightwave energy to strongly enhance light-matter interactions, making them ideal candidates as optical elements for fine-tuning color displays. Inspired by the color mixing effect found on butterfly wings, a new type of plasmonic, multiresonant, narrow-band (the minimum is about 45 nm), high-reflectance (the maximum is about 95%), and dynamic color-tuning reflector is developed. This is achieved from periodic patterns of plasmonic resonant nanocavities in free-standing capped-pillar nanostructure arrays. Such cavity-coupling structures exhibit multiple narrow-band selective and continuously tunable reflections via plasmon standing-wave resonances. Consequently, they can produce a variety of dark-field vibrant reflective colors with good quality, strong color signal and fine tonal variation at the optical diffraction limit. This proposed multicolor scheme provides an elegant strategy for realizing personalized and customized applications in ultracompact photonic data storage and steganography, colorimetric sensing, 3D holograms and other plasmon-assisted photonic devices.

Linear Mathematical Model for Seam Tracking with an Arc Sensor in P-GMAW Processes.

PubMed

Liu, Wenji; Li, Liangyu; Hong, Ying; Yue, Jianfeng

2017-03-14

Arc sensors have been used in seam tracking and widely studied since the 80s and commercial arc sensing products for T and V shaped grooves have been developed. However, it is difficult to use these arc sensors in narrow gap welding because the arc stability and sensing accuracy are not satisfactory. Pulse gas melting arc welding (P-GMAW) has been successfully applied in narrow gap welding and all position welding processes, so it is worthwhile to research P-GMAW arc sensing technology. In this paper, we derived a linear mathematical P-GMAW model for arc sensing, and the assumptions for the model are verified through experiments and finite element methods. Finally, the linear characteristics of the mathematical model were investigated. In torch height changing experiments, uphill experiments, and groove angle changing experiments the P-GMAW arc signals all satisfied the linear rules. In addition, the faster the welding speed, the higher the arc signal sensitivities; the smaller the groove angle, the greater the arc sensitivities. The arc signal variation rate needs to be modified according to the welding power, groove angles, and weaving or rotate speed.

Dynamical heterogeneities and mechanical non-linearities: Modeling the onset of plasticity in polymer in the glass transition.

PubMed

Masurel, R J; Gelineau, P; Lequeux, F; Cantournet, S; Montes, H

2017-12-27

In this paper we focus on the role of dynamical heterogeneities on the non-linear response of polymers in the glass transition domain. We start from a simple coarse-grained model that assumes a random distribution of the initial local relaxation times and that quantitatively describes the linear viscoelasticity of a polymer in the glass transition regime. We extend this model to non-linear mechanics assuming a local Eyring stress dependence of the relaxation times. Implementing the model in a finite element mechanics code, we derive the mechanical properties and the local mechanical fields at the beginning of the non-linear regime. The model predicts a narrowing of distribution of relaxation times and the storage of a part of the mechanical energy --internal stress-- transferred to the material during stretching in this temperature range. We show that the stress field is not spatially correlated under and after loading and follows a Gaussian distribution. In addition the strain field exhibits shear bands, but the strain distribution is narrow. Hence, most of the mechanical quantities can be calculated analytically, in a very good approximation, with the simple assumption that the strain rate is constant.

Membrane emulsification to produce perfume microcapsules

NASA Astrophysics Data System (ADS)

Pan, Xuemiao

Microencapsulation is an efficient technology to deliver perfume oils from consumer products onto the surface of fabrics. Microcapsules having uniform size/mechanical strength, may provide better release performance. Membrane emulsification in a dispersion cell followed by in-situ polymerization was used to prepare narrow size distribution melamine-formaldehyde (MF) microcapsules containing several types of oil-based fragrances or ingredients. Investigated in this study are the parameters impacting to the size and size distribution of the droplets and final MF microcapsules. A pilot plant-scale cross-flow membrane system was also used to produce MF microcapsules, demonstrating that the membrane emulsification process has potential to be scaled up for industrial applications. In this study, health and environmental friendly poly (methyl methacrylate) (PMMA) microcapsules with narrow size distribution were also prepared for the first time using the dispersion cell membrane emulsification system. Characterization methods previously used for thin-shell microcapsules were expanded to analyse microcapsules with thick shells. The intrinsic mechanical properties of thick shells were determined using a micromanipulation technique and finite element analysis (FEM). The microcapsules structure was also considered in the determination of the permeability and diffusivity of the perfume oils in good solvents..

Fiber optic sensors for sub-centimeter spatially resolved measurements: Review and biomedical applications

NASA Astrophysics Data System (ADS)

Tosi, Daniele; Schena, Emiliano; Molardi, Carlo; Korganbayev, Sanzhar

2018-07-01

One of the current frontier of optical fiber sensors, and a unique asset of this sensing technology is the possibility to use a whole optical fiber, or optical fiber device, as a sensor. This solution allows shifting the whole sensing paradigm, from the measurement of a single physical parameter (such as temperature, strain, vibrations, pressure) to the measurement of a spatial distribution, or profiling, of a physical parameter along the fiber length. In the recent years, several technologies are achieving this task with unprecedentedly narrow spatial resolution, ranging from the sub-millimeter to the centimeter-level. In this work, we review the main fiber optic sensing technologies that achieve a narrow spatial resolution: Fiber Bragg Grating (FBG) dense arrays, chirped FBG (CFBG) sensors, optical frequency domain reflectometry (OFDR) based on either Rayleigh scattering or reflective elements, and microwave photonics (MWP). In the second part of the work, we present the impact of spatially dense fiber optic sensors in biomedical applications, where they find the main impact, presenting the key results obtained in thermo-therapies monitoring, high-resolution diagnostic, catheters monitoring, smart textiles, and other emerging applicative fields.

Spatiotemporal Distribution of U5MR and Their Relationship with Geographic and Socioeconomic Factors in China.

PubMed

Li, Zeng; Fu, Jingying; Jiang, Dong; Lin, Gang; Dong, Donglin; Yan, Xiaoxi

2017-11-21

Epidemiological studies conducted around the world have reported that the under-five mortality rate (U5MR) is closely associated with income and educational attainment. However, geographic elements should also remain a major concern in further improving child health issues, since they often play an important role in the survival environment. This study was undertaken to investigate the relationship between the U5MR, geographic, and socioeconomic factors, and to explore the associated spatial variance of the relationship in China using the geographically weighted regression (GWR) model. The results indicate that the space pattern of a high U5MR had been narrowed notably during the period from 2001 to 2010. Nighttime lights (NL) and the digital elevation model (DEM) both have obvious influences on the U5MR, with the NL having a negative impact and DEM having a positive impact. Additionally, the relationship between the NL and DEM varied over space in China. Moreover, the relevance between U5MR and DEM was narrowed in 2010 compared to 2001, which indicates that the development of economic and medical standards can overcome geographical limits.

Supporting the Essential Elements with CD-ROM Storybooks

ERIC Educational Resources Information Center

Pearman, Cathy J.; Lefever-Davis, Shirley

2006-01-01

CD-ROM storybooks can support the development of the five essential elements of reading instruction identified by The National Reading Panel: phonemic awareness, phonics, fluency, vocabulary, and comprehension. Specific features inherent in these texts, audio pronunciation of text, embedded vocabulary definitions and animated graphics can be used…

Inappropriate Use of Homeostasis Model Assessment Cutoff Values for Diagnosing Insulin Resistance in Pediatric Studies.

PubMed

Fox, Carrie; Bernardino, Lourdes; Cochran, Jill; Essig, Mary; Bridges, Kristie Grove

2017-11-01

Assessing pediatric patients for insulin resistance is one way to identify those who are at a high risk of developing type 2 diabetes mellitus. The homoeostasis model assessment (HOMA) is a measure of insulin resistance based on fasting blood glucose and insulin levels. Although this measure is widely used in research, cutoff values for pediatric populations have not been established. To assess the validity of HOMA cutoff values used in pediatric studies published in peer-reviewed journals. Studies published from January 2010 to December 2015 were identified through MEDLINE. Initial screening of abstracts was done to select studies that were conducted in pediatric populations and used HOMA to assess insulin resistance. Subsequent full-text review narrowed the list to only those studies that used a specific HOMA score to diagnose insulin resistance. Each study was classified as using a predetermined fixed HOMA cutoff value or a cutoff that was a percentile specific to that population. For studies that used a predetermined cutoff value, the references cited to provide evidence in support of that cutoff were evaluated. In the 298 articles analyzed, 51 different HOMA cutoff values were used to classify patients as having insulin resistance. Two hundred fifty-five studies (85.6%) used a predetermined fixed cutoff value, but only 72 (28.2%) of those studies provided a reference that supported its use. One hundred ten studies (43%) that used a fixed cutoff either cited a study that did not mention HOMA or provided no reference at all. Tracing of citation history indicated that the most commonly used cutoff values were ultimately based on studies that did not validate their use for defining insulin resistance. Little evidence exists to support HOMA cutoff values commonly used to define insulin resistance in pediatric studies. These findings highlight the importance of validating study design elements when training medical students and novice investigators. Using available data to generate population ranges for HOMA would improve its clinical utility.

Status of the EDDA experiment at COSY

NASA Astrophysics Data System (ADS)

Scobel, W.; EDDA Collaboration; Bisplinghoff, J.; Bollmann, R.; Cloth, P.; Dohrmann, F.; Dorner, G.; Drüke, V.; Ernst, J.; Eversheim, P. D.; Filges, D.; Gasthuber, M.; Gebel, R.; Groß, A.; Groß-Hardt, R.; Hinterberger, F.; Jahn, R.; Lahr, U.; Langkau, R.; Lippert, G.; Mayer-Kuckuk, T.; Maschuw, R.; Mertler, G.; Metsch, B.; Mosel, F.; Paetz gen Schieck, H.; Petry, H. R.; Prasuhn, D.; von Przewoski, B.; Rohdjeß, H.; Rosendaal, D.; von Rossen, P.; Scheid, H.; Schirm, N.; Schwandt, F.; Stein, H.; Theis, D.; Weber, J.; Wiedmann, W.; Woller, K.; Ziegler, R.

1993-07-01

The EDDA experiment is designed to study p + p excitation functions with high energy resolution and narrow step size in the kinetic energy range from 250 MeV to 2500 MeV at the Cooler Synchrotron COSY. Measurements during the accelertion phase in conjunction with internal targets will allow to achieve a fast and precise energy variation. Prototypes of the detector elements and the fiber target have been extensively tested with proton and electron beams; the detector performance and trigger efficiency have been studied in Monte Carlo simulations. In this contribution, results concerning detector design, prototype studies, Monte Carlo simulations and the anticipated detector resolutions will be reported.

Calculating Second-Order Effects in MOSFET's

NASA Technical Reports Server (NTRS)

Benumof, Reuben; Zoutendyk, John A.; Coss, James R.

1990-01-01

Collection of mathematical models includes second-order effects in n-channel, enhancement-mode, metal-oxide-semiconductor field-effect transistors (MOSFET's). When dimensions of circuit elements relatively large, effects neglected safely. However, as very-large-scale integration of microelectronic circuits leads to MOSFET's shorter or narrower than 2 micrometer, effects become significant in design and operation. Such computer programs as widely-used "Simulation Program With Integrated Circuit Emphasis, Version 2" (SPICE 2) include many of these effects. In second-order models of n-channel, enhancement-mode MOSFET, first-order gate-depletion region diminished by triangular-cross-section deletions on end and augmented by circular-wedge-cross-section bulges on sides.

High-power linearly-polarized operation of a cladding-pumped Yb fibre laser using a volume Bragg grating for wavelength selection.

PubMed

Jelger, P; Wang, P; Sahu, J K; Laurell, F; Clarkson, W A

2008-06-23

In this work a volume Bragg grating is used as a wavelength selective element in a high-power cladding-pumped Yb-doped silica fiber laser. The laser produced 138 W of linearly-polarized single-spatial-mode output at 1066 nm with a relatively narrow linewidth of 0.2 nm for approximately 202 W of launched pump power at 976 nm. The beam propagation factor (M(2)) for the output beam was determined to be 1.07. Thermal limitations of volume Bragg gratings are discussed in the context of power scaling for fiber lasers.

Microstructure characterization of the non-modulated martensite in Ni-Mn-Ga alloy

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

Han, M.; Bennett, J.C.; Gharghouri, M.A.

2008-06-15

The microstructure of the non-modulated martensite in a Ni-Mn-Ga alloy has been characterized in detail by conventional transmission electron microscopy. Bright field images show that the martensite exhibits an internal substructure consisting of a high density of narrow twins. Using electron diffraction, it is found that the martensite has a tetragonal crystal structure. The lattice correspondence between the parent phase and the non-modulated martensite is investigated. Furthermore, the four twinning elements describing the microtwinning have been graphically and quantitatively determined. The results indicate that the microtwinning within the non-modulated martensite belongs to the compound type.

Cyclooxygenase Reaction Mechanism of PGHS ------- Evidence for a Reversible Transition between a Pentadienyl Radical and a New Tyrosyl Radical by Nitric Oxide Trapping

PubMed Central

Lü, Jian-Ming; Rogge, Corina E.; Wu, Gang; Kulmacz, Richard J.; van der Donk, Wilfred A.; Tsai, Ah-lim

2011-01-01

Incubation of prostaglandin H synthase-1 (PGHS-1) under anaerobic conditions with peroxide and arachidonic acid leads to two major radical species: a pentadienyl radical and a radical with a narrow EPR spectrum. The proportions of the two radicals are sensitive to temperature, favoring the narrow radical species at 22 °C. The EPR characteristics of this latter radical are somewhat similar to the previously reported narrow-singlet tyrosine radical NS1a and are insensitive to deuterium labeling of AA. To probe the origin and structure of this radical, we combined EPR analysis with nitric oxide (NO) trapping of tyrosine and substrate derived radicals for both PGHS-1 and -2. Formation of 3-nitrotyrosine in the proteins was analyzed by immunoblotting, whereas NO adducts to AA and AA metabolites were analyzed by mass spectrometry and by chromatography of 14C-labeled products. The results indicate that both nitrated tyrosine residues and NO-AA adducts formed upon NO trapping. The NO-AA adduct was predominantly an oxime at C11 of AA with three conjugated double bonds, as indicated by absorption at 275 nm and by mass spectral analysis. This adduct amounted to 10% and 20% of the heme concentration of PGHS-1 and -2, respectively. For PGHS-1, the yield of NO-AA adduct matched the yield of the narrow radical signal obtained in parallel EPR experiments. High frequency EPR characterization of this narrow radical, reported in an accompanying paper, supports assignment to a new tyrosyl radical, NS1c, rather than an AA-based radical. To reconcile the results from EPR and NO-trapping studies, we propose that the NS1c is in equilibrium with an AA pentadienyl radical, and that the latter reacts preferentially with NO. PMID:21403766

Field ionizing elements and applications thereof

NASA Technical Reports Server (NTRS)

Hartley, Frank T. (Inventor)

2003-01-01

A field ionizing element formed of a membrane that houses electrodes therein that are located closer to one another than the mean free path of the gas being ionized. The membrane includes a supporting portion, and a non supporting portion where the ions are formed. The membrane may be used as the front end for a number of different applications including a mass spectrometer, a thruster, an ion mobility element, or an electrochemical device such as a fuel cell.

Major and trace element and volatile constraints on magma systematics of seamounts and axial ridge glasses from the East Pacific Rise between 8°N and 12°N

NASA Astrophysics Data System (ADS)

Lytle, M. L.; Kelley, K. A.; Wanless, V. D.; Hauri, E. H.

2017-12-01

The East Pacific Rise is a fast spreading mid-ocean ridge system (6-16cm/yr) consisting of many spreading ridges and transform faults. Focusing on a well-studied segment between 8-12°N, we present new SIMS measurements of magmatic volatiles (H2O, CO2, S, Cl, F) and new LA-ICP-MS trace element data in both on-axis and off-axis glasses, coupled with previously published data and use these data to relate melt composition to crystallization and melting processes. The seamounts range in composition from evolved (MgO = 5.54 wt%) to fairly primitive (MgO = 9.70 wt%), whereas on-axis samples have a narrower range of MgO (5.85 - 8.83 wt%). Seamounts span a wide range of enrichment in trace element compositions (La/Sm 0.45 - 4.63; Th/La 0.02 - 0.14; K/Ti 0.02 - 0.66), whereas on-axis glasses reflect NMORB compositions (La/Sm 0.5 - 1; Th/La 0.035 - 0.07; K/Ti 0.05 - 0.15). Light rare earth elements in the seamounts vary from depleted to enriched and have variable Eu anomalies (0.79 - 1.10), while on-axis samples have NMORB patterns with more negative Eu anomalies (0.74 - 1.00). The H2O content of the seamounts ranges from dry (0.05 wt%) to fairly wet (0.96 wt%), whereas on-axis samples have a narrower range (0.15 - 0.31 wt%). Cl contents show variable mixing between seawater and a magmatic component, with seamounts assimilating more seawater. Magmatic liquid lines of descent (LLD), recorded in glass, reflect fractional crystallization of olivine, plagioclase, and clinopyroxene, consistent with modal phenocryst abundances of the rocks. A multi-element approach (e.g., MgO vs. Al2O3, CaO, CaO/Al2O3), constrains LLDs, providing fractionation slopes, allowing mafic basalt compositions to be accurately corrected back to primary melts in equilibrium with Fo90. Using these melts, pressures and temperatures of melt equilibration can be constrained using melt thermobarometry. On-axis samples reflect higher PT conditions (1371°C; 1.37 GPa), although within error of seamounts (1340°C; 1.25 GPa). Overall, on-axis samples are more homogeneous, likely reflecting residence and homogenization of magma batches in an axial magma chamber, whereas off-axis seamounts reflect greater heterogeneity that arises from the localized nature of seamount magmatic systems and extraction of smaller-volume, discrete magma batches from the ridge mantle.

Flexible organic transistors and circuits with extreme bending stability

NASA Astrophysics Data System (ADS)

Sekitani, Tsuyoshi; Zschieschang, Ute; Klauk, Hagen; Someya, Takao

2010-12-01

Flexible electronic circuits are an essential prerequisite for the development of rollable displays, conformable sensors, biodegradable electronics and other applications with unconventional form factors. The smallest radius into which a circuit can be bent is typically several millimetres, limited by strain-induced damage to the active circuit elements. Bending-induced damage can be avoided by placing the circuit elements on rigid islands connected by stretchable wires, but the presence of rigid areas within the substrate plane limits the bending radius. Here we demonstrate organic transistors and complementary circuits that continue to operate without degradation while being folded into a radius of 100μm. This enormous flexibility and bending stability is enabled by a very thin plastic substrate (12.5μm), an atomically smooth planarization coating and a hybrid encapsulation stack that places the transistors in the neutral strain position. We demonstrate a potential application as a catheter with a sheet of transistors and sensors wrapped around it that enables the spatially resolved measurement of physical or chemical properties inside long, narrow tubes.

Twelve years of IUE spectra of the interacting binary VV Cephei

NASA Technical Reports Server (NTRS)

Bauer, W. H.; Stencel, R. E.; Neff, D. H.

1991-01-01

All well-exposed high-resolution IUE spectra obtained of the eclipsing binary system VV Cephei (M2Iabep + B) are examined. High-temperature absorption features attributable to the hot companion were detected, indicating that the companion (or the inner regions of its accretion disk) are not as hot as a B1-B2 star. Doubling of Fe II (UV 1) lines, with an additional narrow component redshifted by about 60 km/sec, occurs only when the B star is behind the plane of the sky containing the M supergiant, suggesting the existence of mass transfer from the red to the blue star. Absorption features from neutral elements weaken dramatically during egress, while those from ionized elements remain at nearly constant strength. During egress from primary eclipse, the Mg II resonance doublet shows asymmetric double-peaked emission indicative of formation in an expanding chromosphere. It is concluded that the outer atmosphere of the M supergiant is highly clumped.

Deficit in visual temporal integration in autism spectrum disorders.

PubMed

Nakano, Tamami; Ota, Haruhisa; Kato, Nobumasa; Kitazawa, Shigeru

2010-04-07

Individuals with autism spectrum disorders (ASD) are superior in processing local features. Frith and Happe conceptualize this cognitive bias as 'weak central coherence', implying that a local enhancement derives from a weakness in integrating local elements into a coherent whole. The suggested deficit has been challenged, however, because individuals with ASD were not found to be inferior to normal controls in holistic perception. In these opposing studies, however, subjects were encouraged to ignore local features and attend to the whole. Therefore, no one has directly tested whether individuals with ASD are able to integrate local elements over time into a whole image. Here, we report a weakness of individuals with ASD in naming familiar objects moved behind a narrow slit, which was worsened by the absence of local salient features. The results indicate that individuals with ASD have a clear deficit in integrating local visual information over time into a global whole, providing direct evidence for the weak central coherence hypothesis.

Design and Simulation of Optically Actuated Bistable MEMS

NASA Astrophysics Data System (ADS)

Lucas, Thomas; Moiseeva, Evgeniya; Harnett, Cindy

2012-02-01

In this project, bistable three-dimensional MEMS actuators are designed to be optically switched between stable states for biological research applications. The structure is a strained rectangular frame created with stress-mismatched metal-oxide bilayers. The devices curl into an arc in one of two directions tangent to the substrate, and can switch orientation when regions are selectively heated. The heating is powered by infrared laser, and localized with patterned infrared-resonant gold nanoparticles on critical regions. The enhanced energy absorption on selected areas provides switching control and heightened response to narrow-band infrared light. Coventorware has been used for finite element analysis of the system. The numerical simulations indicate that it has two local minimum states with extremely rapid transition time (<<0.1 s) when the structure is thermally deformed. Actuation at laser power and thermal limits compatible with physiological applications will enable microfluidic pumping elements and fundamental studies of tissue response to three-dimensional mechanical stimuli, artificial-muscle based pumps and other biomedical devices triggered by tissue-permeant infrared light.

Quantification of cellular penetrative forces using lab-on-a-chip technology and finite element modeling

PubMed Central

Sanati Nezhad, Amir; Naghavi, Mahsa; Packirisamy, Muthukumaran; Bhat, Rama; Geitmann, Anja

2013-01-01

Tip-growing cells have the unique property of invading living tissues and abiotic growth matrices. To do so, they exert significant penetrative forces. In plant and fungal cells, these forces are generated by the hydrostatic turgor pressure. Using the TipChip, a microfluidic lab-on-a-chip device developed for tip-growing cells, we tested the ability to exert penetrative forces generated in pollen tubes, the fastest-growing plant cells. The tubes were guided to grow through microscopic gaps made of elastic polydimethylsiloxane material. Based on the deformation of the gaps, the force exerted by the elongating tubes to permit passage was determined using finite element methods. The data revealed that increasing mechanical impedance was met by the pollen tubes through modulation of the cell wall compliance and, thus, a change in the force acting on the obstacle. Tubes that successfully passed a narrow gap frequently burst, raising questions about the sperm discharge mechanism in the flowering plants. PMID:23630253

Sensitive elemental detection using microwave-assisted laser-induced breakdown imaging

NASA Astrophysics Data System (ADS)

Iqbal, Adeel; Sun, Zhiwei; Wall, Matthew; Alwahabi, Zeyad T.

2017-10-01

This study reports a sensitive spectroscopic method for quantitative elemental detection by manipulating the temporal and spatial parameters of laser-induced plasma. The method was tested for indium detection in solid samples, in which laser ablation was used to generate a tiny plasma. The lifetime of the laser-induced plasma can be extended to hundreds of microseconds using microwave injection to remobilize the electrons. In this novel method, temporal integrated signal of indium emission was significantly enhanced. Meanwhile, the projected detectable area of the excited indium atoms was also significantly improved using an interference-, instead of diffraction-, based technique, achieved by directly imaging microwave-enhanced plasma through a novel narrow-bandpass filter, exactly centered at the indium emission line. Quantitative laser-induce breakdown spectroscopy was also recorded simultaneously with the new imaging method. The intensities recorded from both methods exhibit very good mutual linear relationship. The detection intensity was improved to 14-folds because of the combined improvements in the plasma lifetime and the area of detection.

Holographic Optical Elements as Scanning Lidar Telescopes

NASA Technical Reports Server (NTRS)

Schwemmer, Geary K.; Rallison, Richard D.; Wilkerson, Thomas D.; Guerra, David V.

2005-01-01

We have developed and investigated the use of holographic optical elements (HOEs) and holographic transmission gratings for scanning lidar telescopes. For example, rotating a flat HOE in its own plane with the focal spot on the rotation axis makes a very simple and compact conical scanning telescope. We developed and tested transmission and reflection HOEs for use at the first three harmonic wavelengths of Nd:YAG lasers. The diffraction efficiency, diffraction angle, focal length, focal spot size and optical losses were measured for several HOEs and holographic gratings, and found to be suitable for use as lidar receiver telescopes, and in many cases could also serve as the final collimating and beam steering optic for the laser transmitter. Two lidar systems based on this technology have been designed, built, and successfully tested in atmospheric science applications. This technology will enable future spaceborne lidar missions by significantly lowering the size, weight, power requirement and cost of a large aperture, narrow field of view scanning telescope.

Zone-boundary optimization for direct laser writing of continuous-relief diffractive optical elements.

PubMed

Korolkov, Victor P; Nasyrov, Ruslan K; Shimansky, Ruslan V

2006-01-01

Enhancing the diffraction efficiency of continuous-relief diffractive optical elements fabricated by direct laser writing is discussed. A new method of zone-boundary optimization is proposed to correct exposure data only in narrow areas along the boundaries of diffractive zones. The optimization decreases the loss of diffraction efficiency related to convolution of a desired phase profile with a writing-beam intensity distribution. A simplified stepped transition function that describes optimized exposure data near zone boundaries can be made universal for a wide range of zone periods. The approach permits a similar increase in the diffraction efficiency as an individual-pixel optimization but with fewer computation efforts. Computer simulations demonstrated that the zone-boundary optimization for a 6 microm period grating increases the efficiency by 7% and 14.5% for 0.6 microm and 1.65 microm writing-spot diameters, respectively. The diffraction efficiency of as much as 65%-90% for 4-10 microm zone periods was obtained experimentally with this method.

The fate of moderately volatile elements during planetary formation in the inner Solar System

NASA Astrophysics Data System (ADS)

Pringle, E. A.; Moynier, F.

2017-12-01

Moderately volatile element abundances are variable among inner Solar System bodies, with differing degrees of depletion compared to chondrites. These variations are a consequence of the processes of planetary formation. The conditions and the specific mechanisms of planetary accretion and differentiation can be investigated by analyzing the stable isotope compositions of terrestrial and extraterrestrial samples. The moderately volatile lithophile elements are particularly useful to distinguish between the effects of accretion and those of core formation. Recent work has shown isotope variations in inner Solar System bodies for the moderately volatile elements Zn and K. The purely lithophile nature of Rb (in contrast to Zn) and the higher volatility of Rb compared to K make Rb an ideal element with which to further study moderately volatile element depletion. We have developed a new method for the high-precision measurement of Rb isotope ratios by MC-ICP-MS. Terrestrial rocks define a narrow range in Rb isotope composition, indicating that Rb isotope fractionation during igneous differentiation is limited (<30 ppm/amu). Larger Rb isotope variations are observed in extraterrestrial materials. Carbonaceous chondrites display a trend toward lighter Rb isotope composition coupled with decreasing Rb/Sr, opposite to the effect expected if their volatile element variations were caused by evaporative loss of Rb. This relationship indicates that the volatile element abundance variations in carbonaceous chondrites are not due to evaporation or condensation, but rather are due to the mixing of chemically and isotopically distinct primordial reservoirs. In contrast, there is a clear signature of Rb loss during evaporation in volatile-depleted achondrites and lunar rocks. Significant heavy isotope enrichments (up to several per mil for 87Rb/85Rb) are found for volatile-depleted planetesimals, including eucrites. In addition, lunar rocks also display heavy Rb isotope enrichments compared to the BSE. The most likely cause of these variations is Rb isotope fractionation due to evaporation during accretion.

Composite battery separator

NASA Technical Reports Server (NTRS)

Edwards, Dean B. (Inventor); Rippel, Wally E. (Inventor)

1987-01-01

A composite battery separator comprises a support element (10) having an open pore structure such as a ribbed lattice and at least one liquid permeable sheet (20,22) to distribute the compressive force evenly onto the surfaces of the layers (24, 26) of negative active material and positive active material. In a non-flooded battery cell the compressible, porous material (18), such as a glass mat which absorbs the electrolyte, is compressed into a major portion of the pores or openings (16) in the support element. The unfilled pores in the material (18) form a gas diffusion path as the channels (41) formed between adjacent ribs in the lattice element (30,36). Facing two lattice elements (30, 31) with acute angled cross-ribs (34, 38) facing each other prevents the elements from interlocking and distorting a porous, separator (42) disposed between the lattice elements.

Quasi-Static Electric Field Generator

NASA Technical Reports Server (NTRS)

Generazio, Edward R. (Inventor)

2017-01-01

A generator for producing an electric field for with an inspection technology system is provided. The generator provides the required variable magnitude quasi-static electric fields for the "illumination" of objects, areas and volumes to be inspected by the system, and produces human-safe electric fields that are only visible to the system. The generator includes a casing, a driven, non-conducting and triboelectrically neutral rotation shaft mounted therein, an ungrounded electrostatic dipole element which works in the quasi-static range, and a non-conducting support for mounting the dipole element to the shaft. The dipole element has a wireless motor system and a charging system which are wholly contained within the dipole element and the support that uses an electrostatic approach to charge the dipole element.

From well-defined Pt(II) surface species to the controlled growth of silica supported Pt nanoparticles.

PubMed

Laurent, Pierre; Veyre, Laurent; Thieuleux, Chloé; Donet, Sébastien; Copéret, Christophe

2013-01-07

Silica-supported Pt nanoparticles were prepared from well-defined surface platinum(II) surface species, obtained by grafting of well-defined Pt(II) molecular precursors with specific ligands (Cl, Me, N(SiMe(3))(2), OSi(OtBu)(3)) onto silica partially dehydroxylated at 200 and 700 °C yielding well-defined platinum(II) surface species. This approach allowed for testing the effect of Pt density and ligands on nanoparticle size. Higher grafting densities are achieved on silica partially dehydroxylated at 200 °C due to its initially higher surface silanol density. Surface species have been synthesized from symmetrical and dissymmetrical complexes, namely (COD)Pt(Me)(2), (COD)Pt(OSi(OtBu)(3))(2), (COD)Pt(Me)(OSi(OtBu)(3)), (COD)Pt(Me)(N(SiMe(3))(2)), (COD)Pt(Cl)(N(SiMe(3))(2)) and (COD)Pt(N(SiMe(3))(2))(OSi(OtBu)(3)) yielding mono-grafted complexes of general formula (COD)Pt(R)(OSi≡) according to elemental analyses, diffuse reflectance infrared fourier transform (DRIFT) and carbon-13 solid-state nuclear magnetic resonance (NMR) spectroscopies. While the dimethyl-complex shows low reactivity towards grafting, bis-siloxy and dissymmetric complexes demonstrate better reactivity yielding platinum loadings up to 7.4 wt%. Upon grafting amido complexes, the surface passivation yielding Me(3)SiOSi≡ surface species is demonstrated. Nanoparticles have been synthesized from these well-defined surface species by reduction under H(2) at 300 °C, under static or flow conditions. This process yields nanoparticles with sizes ranging from 2 to 3.3 nm and narrow size dispersion from 0.5 to 1.2 nm. Interestingly, the chloride complex yields large nanoparticles from 5 to 40 nm demonstrating the strong influence of chloride over the nanoparticles growth.

Data Element Dictionary: Staff. Second Edition.

ERIC Educational Resources Information Center

Martin, James S.

This document is intended to serve as a guide for institutions in the development of data bases to support the implementation of planning and management systems. This publication serves to identify and describe those staff-related data elements: (1) required to support current National Center for Higher Education Management Systems (NCHEMS)…

Data Element Dictionary: Facilities. Second Edition.

ERIC Educational Resources Information Center

Martin, James S.

This document is intended to serve as a guide for institutions in the development of data bases to support the implementation of planning and management systems. This publication serves to identify and describe those facilities-related data elements: (1) required to support current National Center for Higher Education Management Systems (NCHEMS)…

Data Element Dictionary: Course. Second Edition.

ERIC Educational Resources Information Center

Martin, James S.

This document is intended to serve as a guide for institutions in the development of data bases to support the implementation of planning and management systems. This publication serves to identify and describe those course-related data elements: (1) required to support current National Center for Higher Education Management Systems (NCHEMS)…

Data Element Dictionary: Finance. Second Edition.

ERIC Educational Resources Information Center

Martin, James S.

This document is intended to serve as a guide for institutions in the development of data bases to support the implementation of planning and management systems. This publication serves to identify and describe those finance-related data elements: (1) required to support current National Center for Higher Education Management Systems (NCHEMS)…

Data Element Dictionary: Student. Second Edition.

ERIC Educational Resources Information Center

Martin, James S.

This document is intended to serve as a guide for institutions in the development of data bases to support the implementation of planning and management systems. This publication serves to identify and describe those student-related data elements: (1) required to support current National Center for Higher Education Systems (NCHEMS) products; (2)…

CEDS Addresses: Virtual and Blended Learning

ERIC Educational Resources Information Center

US Department of Education, 2015

2015-01-01

The Common Education Data Standards (CEDS) common data vocabulary supports the collection and use of information about virtual and blended learning. The data element "Virtual Indicator", introduced in version 3 of CEDS, supports a range of virtual learning-related use cases. The Virtual Indicator element may be related to a Course…

Small ICBM area narrowing report. Volume 1. Hard mobile launcher in random movement basing mode

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

Not Available

The purpose of this report is to identify those areas that could potentially support deployment of the Small Intercontinental Ballistic Missile (ICBM) utilizing basing modes presently considered viable: the Hard Mobile Launcher in Random Movement, the Hard Mobile Launcher at Minuteman Facilities, and the Hard Silo in Patterned Array. Specifically, this report describes the process and the rationale supporting the application of Exclusionary and Evaluative Criteria and lists those locations that were eliminated through the application of these criteria. The remaining locations will be the subject of further investigations.

Small ICBM area narrowing report. Volume 2. Hard mobile launcher at minuteman facilities basing mode

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

Not Available

The purpose of this report is to identify those areas that could potentially support deployment of the Small Intercontinental Ballistic Missile (ICBM) utilizing basing modes presently considered viable: the Hard Mobile Launcher in Random Movement, the Hard Mobile Launcher at Minuteman Facilities, and the Hard Silo in Patterned Array. Specifically, this report describes the process and the rationale supporting the application of Exclusionary and Evaluative Criteria and lists those locations that were eliminated through the application of these criteria. The remaining locations will be the subject of further investigations.

Phase Space Generation for Proton and Carbon Ion Beams for External Users' Applications at the Heidelberg Ion Therapy Center.

PubMed

Tessonnier, Thomas; Marcelos, Tiago; Mairani, Andrea; Brons, Stephan; Parodi, Katia

2015-01-01

In the field of radiation therapy, accurate and robust dose calculation is required. For this purpose, precise modeling of the irradiation system and reliable computational platforms are needed. At the Heidelberg Ion Therapy Center (HIT), the beamline has been already modeled in the FLUKA Monte Carlo (MC) code. However, this model was kept confidential for disclosure reasons and was not available for any external team. The main goal of this study was to create efficiently phase space (PS) files for proton and carbon ion beams, for all energies and foci available at HIT. PSs are representing the characteristics of each particle recorded (charge, mass, energy, coordinates, direction cosines, generation) at a certain position along the beam path. In order to achieve this goal, keeping a reasonable data size but maintaining the requested accuracy for the calculation, we developed a new approach of beam PS generation with the MC code FLUKA. The generated PSs were obtained using an infinitely narrow beam and recording the desired quantities after the last element of the beamline, with a discrimination of primaries or secondaries. In this way, a unique PS can be used for each energy to accommodate the different foci by combining the narrow-beam scenario with a random sampling of its theoretical Gaussian beam in vacuum. PS can also reproduce the different patterns from the delivery system, when properly combined with the beam scanning information. MC simulations using PS have been compared to simulations, including the full beamline geometry and have been found in very good agreement for several cases (depth dose distributions, lateral dose profiles), with relative dose differences below 0.5%. This approach has also been compared with measured data of ion beams with different energies and foci, resulting in a very satisfactory agreement. Hence, the proposed approach was able to fulfill the different requirements and has demonstrated its capability for application to clinical treatment fields. It also offers a powerful tool to perform investigations on the contribution of primary and secondary particles produced in the beamline. These PSs are already made available to external teams upon request, to support interpretation of their measurements.

Two Sides of the Same Coin: U. S. "Residual" Inequality and the Gender Gap

ERIC Educational Resources Information Center

Bacolod, Marigee P.; Blum, Bernardo S.

2010-01-01

We show that the narrowing gender gap and the growth in earnings inequality are consistent with a simple model in which skills are heterogeneous, and the growth in skill prices has been particularly strong for skills with which women are well endowed. Empirical analysis of DOT, CPS, and NLSY79 data finds evidence to support this model. A large…

Beyond the Straight and Narrow: Librarians Can Give Gay Teens the Support They Need

ERIC Educational Resources Information Center

Jones, Jami

2004-01-01

For gay students, some always feel like they are wearing a mask. They cannot let their family, even their friends, see the real them. According to researchers, the road to adulthood for gay, lesbian, bisexual, and transgendered teens is riddled with more potholes than for other teens. For starters, gay teens are two to three times more likely to…

Airline Wheelchair

NASA Technical Reports Server (NTRS)

1982-01-01

Accutron Tool & Instrument Co.'s wheelchair was designed to increase mobility within the airplane. Utilizing NASA's structural analysis and materials engineering technologies, it allows passage through narrow airline aisles to move passengers to their seats and give access to lavatories. Stable, durable, comfortable and easy to handle, it's made of composite materials weighing only 17 pounds, yet is able to support a 200 pound person. Folded easily and stored when not in use.

Quality management and the work environment: an empirical investigation in a public sector organization.

PubMed

Taveira, Alvaro D; James, Craig A; Karsh, Ben -Tzion; Sainfort, François

2003-07-01

The integration of quality management initiatives, particularly total quality management (TQM), and ergonomics has received increasing attention from scholars and practitioners. Above all, the question of how TQM programs relate to ergonomic aspects of organizational design and culture is at the center of this discussion. This study examines how elements of a "typical", Deming-inspired, TQM program in the public sector interact with the work environment. Elements of the TQM program were defined and measured using the Malcom Baldridge Award criteria. The specific elements examined were "Management Support of Quality", "Information and Analysis", "Human Resources", "Processes and Quality Results", and "Customer Focus and Satisfaction". The relationship between these TQM elements and the work environment were defined through five separate hypotheses. The work environment was described by the constructs "Supervisor Support", "Task Clarity", "Task Orientation", and "Innovation". Data were obtained through survey questionnaires administered to employees of four departments in a municipal government organization. Results supported three of the hypotheses, but produced some unanticipated outcomes with regard to the other two. Namely, "Management Support of Quality" was significantly related to "Supervisor Support", "Task Orientation", "Task Clarity" and "Innovation"; "Human Resources" was significantly related to "Supervisor Support"; "Processes and Quality Results" was significantly related to "Task Orientation" and "Innovation". Contrary to predicted "Information and Analysis" was negatively related to "Innovation", and "Customer Focus" was unrelated to any of the outcome variables. The relationships between these TQM elements and work environment dimensions are discussed. Implications for TQM and ergonomic practice are analyzed, and directions for future research proposed.

Hardware support for collecting performance counters directly to memory

DOEpatents

Gara, Alan; Salapura, Valentina; Wisniewski, Robert W.

2012-09-25

Hardware support for collecting performance counters directly to memory, in one aspect, may include a plurality of performance counters operable to collect one or more counts of one or more selected activities. A first storage element may be operable to store an address of a memory location. A second storage element may be operable to store a value indicating whether the hardware should begin copying. A state machine may be operable to detect the value in the second storage element and trigger hardware copying of data in selected one or more of the plurality of performance counters to the memory location whose address is stored in the first storage element.

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

Tsujimoto, Takuji; Shigeyama, Toshikazu, E-mail: taku.tsujimoto@nao.ac.jp

Growing interests in neutron star (NS) mergers as the origin of r-process elements have sprouted since the discovery of evidence for the ejection of these elements from a short-duration γ-ray burst. The hypothesis of a NS merger origin is reinforced by a theoretical update of nucleosynthesis in NS mergers successful in yielding r-process nuclides with A > 130. On the other hand, whether the origin of light r-process elements are associated with nucleosynthesis in NS merger events remains unclear. We find a signature of nucleosynthesis in NS mergers from peculiar chemical abundances of stars belonging to the Galactic globular cluster M15.more » This finding combined with the recent nucleosynthesis results implies a potential diversity of nucleosynthesis in NS mergers. Based on these considerations, we are successful in the interpretation of an observed correlation between [light r-process/Eu] and [Eu/Fe] among Galactic halo stars and accordingly narrow down the role of supernova nucleosynthesis in the r-process production site. We conclude that the tight correlation by a large fraction of halo stars is attributable to the fact that core-collapse supernovae produce light r-process elements while heavy r-process elements such as Eu and Ba are produced by NS mergers. On the other hand, stars in the outlier, composed of r-enhanced stars ([Eu/Fe] ≳ +1) such as CS22892-052, were exclusively enriched by matter ejected by a subclass of NS mergers that is inclined to be massive and consist of both light and heavy r-process nuclides.« less

High-Voltage Breakdown Penalties for the Beam-Breakup Instability

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

Ekdahl, Carl August

2016-11-22

The strength of the dangerous beam breakup (BBU) instability in linear induction accelerators (LIAs) is determined by the transverse coupling impedance Z ⊥ of the induction cell cavity. For accelerating gap width w less than the beam pipe radius b, the transverse impedance is theoretically proportional to w/b, favoring narrow gaps to suppress BBU. On the other hand, cells with narrow gaps cannot support high accelerating gradients, because of electrical breakdown and shorting of the gap. Thus, there is an engineering trade-off between BBU growth and accelerating gradient, which must be considered for next generation LIAs now being designed. Inmore » this article this tradeoff is explored, using a simple pillbox cavity as an illustrative example. For this model, widening the gap to reduce the probability of breakdown increases BBU growth, unless higher magnetic focusing fields are used to further suppress the instability.« less

Specific minor groove solvation is a crucial determinant of DNA binding site recognition

PubMed Central

Harris, Lydia-Ann; Williams, Loren Dean; Koudelka, Gerald B.

2014-01-01

The DNA sequence preferences of nearly all sequence specific DNA binding proteins are influenced by the identities of bases that are not directly contacted by protein. Discrimination between non-contacted base sequences is commonly based on the differential abilities of DNA sequences to allow narrowing of the DNA minor groove. However, the factors that govern the propensity of minor groove narrowing are not completely understood. Here we show that the differential abilities of various DNA sequences to support formation of a highly ordered and stable minor groove solvation network are a key determinant of non-contacted base recognition by a sequence-specific binding protein. In addition, disrupting the solvent network in the non-contacted region of the binding site alters the protein's ability to recognize contacted base sequences at positions 5–6 bases away. This observation suggests that DNA solvent interactions link contacted and non-contacted base recognition by the protein. PMID:25429976

Bronchoscopic phototherapy at comparable dose rates: Early results

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

Pass, H.I.; Delaney, T.; Smith, P.D.

1989-05-01

Photodynamic therapy is a recently introduced treatment for surface malignancies. Since January 1987, 10 patients with endobronchial neoplasms have had bronchoscopic photodynamic therapy at similar dose rates (400 mW/cm) for total atelectasis (2), carinal narrowing with respiratory insufficiency (2), or partial obstruction without collapse (4). Two patients underwent photodynamic therapy as a preliminary to immunotherapy. Histologies included endobronchial metastases (colon, ovary, melanoma, and sarcoma, 1 each; and renal cell, 3) and primary lung cancer (3). The 2 patients with total atelectasis had complete reexpansion after photodynamic therapy, which permitted eventual sleeve lobectomy in 1. Carinal narrowing was ameliorated in themore » 2 patients seen with inspiratory stridor, thereby permitting hospital discharge. Endoscopically resected fragments after photodynamic therapy exhibited avascular necrosis. These data support further controlled studies of photodynamic therapy by thoracic surgical oncologists to define its limitations as well as to improve and expand its efficacy as a palliative or surgical adjuvant.« less

DNA Barcodes Confirm the Taxonomic and Conservation Status of a Species of Tree on the Brink of Extinction in the Pacific.

PubMed

Costion, Craig M; Kress, W John; Crayn, Darren M

2016-01-01

The taxonomic status of a single island, narrow range endemic plant species from Palau, Micronesia (Timonius salsedoi) was assessed using DNA barcode markers, additional plastid loci, and morphology in order to verify its conservation status. DNA barcode loci distinguished T. salsedoi from all other Timonius species sampled from Palau, and were supported by sequence data from the atpB-rbcL intergenic spacer region. Timonius salsedoi was only known from two mature individual trees in 2012. Due to its extremely narrow range and population size, it had previously been recommended to be listed as Critically Endangered Status under three separate IUCN Criteria. In 2014 a second survey of the population following a typhoon revealed that the only two known trees had died suggesting that this species may now be extinct. Comprehensive follow up surveys of suitable habitat for this species are urgently required.

Asynchronous glimpsing of speech: Spread of masking and task set-size

PubMed Central

Ozmeral, Erol J.; Buss, Emily; Hall, Joseph W.

2012-01-01

Howard-Jones and Rosen [(1993). J. Acoust. Soc. Am. 93, 2915–2922] investigated the ability to integrate glimpses of speech that are separated in time and frequency using a “checkerboard” masker, with asynchronous amplitude modulation (AM) across frequency. Asynchronous glimpsing was demonstrated only for spectrally wide frequency bands. It is possible that the reduced evidence of spectro-temporal integration with narrower bands was due to spread of masking at the periphery. The present study tested this hypothesis with a dichotic condition, in which the even- and odd-numbered bands of the target speech and asynchronous AM masker were presented to opposite ears, minimizing the deleterious effects of masking spread. For closed-set consonant recognition, thresholds were 5.1–8.5 dB better for dichotic than for monotic asynchronous AM conditions. Results were similar for closed-set word recognition, but for open-set word recognition the benefit of dichotic presentation was more modest and level dependent, consistent with the effects of spread of masking being level dependent. There was greater evidence of asynchronous glimpsing in the open-set than closed-set tasks. Presenting stimuli dichotically supported asynchronous glimpsing with narrower frequency bands than previously shown, though the magnitude of glimpsing was reduced for narrower bandwidths even in some dichotic conditions. PMID:22894234

The evolution of environmental tolerance and range size: a comparison of geographically restricted and widespread Mimulus.

PubMed

Sheth, Seema N; Angert, Amy L

2014-10-01

The geographic ranges of closely related species can vary dramatically, yet we do not fully grasp the mechanisms underlying such variation. The niche breadth hypothesis posits that species that have evolved broad environmental tolerances can achieve larger geographic ranges than species with narrow environmental tolerances. In turn, plasticity and genetic variation in ecologically important traits and adaptation to environmentally variable areas can facilitate the evolution of broad environmental tolerance. We used five pairs of western North American monkeyflowers to experimentally test these ideas by quantifying performance across eight temperature regimes. In four species pairs, species with broader thermal tolerances had larger geographic ranges, supporting the niche breadth hypothesis. As predicted, species with broader thermal tolerances also had more within-population genetic variation in thermal reaction norms and experienced greater thermal variation across their geographic ranges than species with narrow thermal tolerances. Species with narrow thermal tolerance may be particularly vulnerable to changing climatic conditions due to lack of plasticity and insufficient genetic variation to respond to novel selection pressures. Conversely, species experiencing high variation in temperature across their ranges may be buffered against extinction due to climatic changes because they have evolved tolerance to a broad range of temperatures. © 2014 The Author(s). Evolution © 2014 The Society for the Study of Evolution.

Black holes, disks, and jets following binary mergers and stellar collapse: The narrow range of electromagnetic luminosities and accretion rates.

PubMed

Shapiro, Stuart L

2017-05-15

We have performed magnetohydrodynamic simulations in general relativity of binary neutron star and binary black hole-neutron star mergers, as well as the magnetorotational collapse of supermassive stars. In many cases the outcome is a spinnng black hole (BH) immersed in a magnetized disk, with a jet emanating from the poles of the BH. While their formation scenarios differ and their BH masses, as well as their disk masses, densities, and magnetic field strengths, vary by orders of magnitude, these features conspire to generate jet Poynting luminosities that all lie in the same, narrow range of ~10 52±1 erg s -1 . A similar result applies to their BH accretion rates upon jet launch, which is ~0.1-10 M ⊙ s -1 . We provide a simple model that explains these unanticipated findings. Interestingly, these luminosities reside in the same narrow range characterizing the observed luminosity distributions of over 400 short and long GRBs with distances inferred from spectroscopic redshifts or host galaxies. This result, together with the GRB lifetimes predicted by the model, supports the belief that a compact binary merger is the progenitor of an SGRB, while a massive, stellar magnetorotational collapse is the progenitor of an LGRB.

Black holes, disks, and jets following binary mergers and stellar collapse: The narrow range of electromagnetic luminosities and accretion rates

PubMed Central

Shapiro, Stuart L.

2018-01-01

We have performed magnetohydrodynamic simulations in general relativity of binary neutron star and binary black hole-neutron star mergers, as well as the magnetorotational collapse of supermassive stars. In many cases the outcome is a spinnng black hole (BH) immersed in a magnetized disk, with a jet emanating from the poles of the BH. While their formation scenarios differ and their BH masses, as well as their disk masses, densities, and magnetic field strengths, vary by orders of magnitude, these features conspire to generate jet Poynting luminosities that all lie in the same, narrow range of ~1052±1 erg s−1. A similar result applies to their BH accretion rates upon jet launch, which is ~0.1–10 M⊙ s−1. We provide a simple model that explains these unanticipated findings. Interestingly, these luminosities reside in the same narrow range characterizing the observed luminosity distributions of over 400 short and long GRBs with distances inferred from spectroscopic redshifts or host galaxies. This result, together with the GRB lifetimes predicted by the model, supports the belief that a compact binary merger is the progenitor of an SGRB, while a massive, stellar magnetorotational collapse is the progenitor of an LGRB. PMID:29881790

Bandwidth Dependence of Laser Plasma Instabilities Driven by the Nike KrF Laser

NASA Astrophysics Data System (ADS)

Weaver, J. L.; Oh, J.; Seely, J.; Kehne, D.; Brown, C. M.; Obenschain, S.; Serlin, V.; Schmitt, A. J.; Phillips, L.; Lehmberg, R. H.; McLean, E.; Manka, C.; Feldman, U.

2011-10-01

The Nike krypton-fluoride (KrF) laser at the Naval Research Laboratory operates in the deep UV (248 nm) and employs beam smoothing by induced spatial incoherence (ISI). In the first ISI studies at longer wavelengths (1054 nm and 527 nm) [Obenschain, PRL 62, 768(1989);Mostovych, PRL, 59, 1193(1987); Peyser, Phys. Fluids B 3, 1479(1991)], stimulated Raman scattering, stimulated Brillouin scattering, and the two plasmon decay instability were reduced when wide bandwidth ISI (δν / ν ~ 0.03-0.19%) pulses irradiated targets at moderate to high intensities (1014-1015W/cm2) . Recent Nike work showed that the threshold for quarter critical instabilities increased with the expected wavelength scaling, without accounting for the large bandwidth (δν ~ 1-3 THz). New experiments will compare laser plasma instabilities (LPI) driven by narrower bandwidth pulses to those observed with the standard operation. The bandwidth of KrF lasers can be reduced by adding narrow filters (etalons or gratings) in the initial stages of the laser. This talk will discuss the method used to narrow the output spectrum of Nike, the laser performance for this new operating mode, and target observations of LPI in planar CH targets. Work supported by DoE/NNSA.

Experimental Characterization of Thermo-electric Driven Liquid Lithium Flow in Narrow Trenches for Magnetic Confinement Fusion

NASA Astrophysics Data System (ADS)

Xu, Wenyu; Christenson, Michael; Fiflis, Peter; Curreli, Davide; Andruczyk, Daniel; Ruzic, David

2013-10-01

The application of liquid metal, especially liquid lithium has become an important topic for plasma facing component (PFC) design. A liquid PFC can effectively eliminate the erosion and thermal stress problems compared to the solid PFC while transferring heat and prolong the lifetime limit of the PFCs. A liquid lithium surface can also suppress the hydrogen isotopes recycling and getter the impurities in fusion reactors. The Lithium/metal infused trench (LiMIT) concept successfully proved that the thermoelectric effect can be utilized to drive liquid lithium flow within horizontally placed metallic open trenches in transverse magnetic field. A limiter based on this concept was tested in HT-7 and gave out positive results. However a broader application of this concept may require the trench be tilted or even placed vertically, for which strong capillary force caused by narrow trenches may be the solution. A new LiMIT design with very narrow trenches have been manufactured and tested in University of Illinois and related results will be presented. Based on this idea new limiters are designed for EAST and LTX and scheduled experiments on both devices will be discussed. This project is supported by DOE/ALPS contract: DEFG02- 99ER54515.

Ridge expansion and immediate placement with piezosurgery and screw expanders in atrophic maxillary sites: two case reports.

PubMed

Kelly, Andrew; Flanagan, Dennis

2013-02-01

Endosseous dental implants may require bone augmentation before implant placement. Herein is described an approach to edentulous ridge expansion with the use of piezosurgery and immediate placement of implants. This may allow for a shortened treatment time and the elimination of donor-site morbidity. Two cases are reported. This technique uses a piezoelectric device to cut the crestal and proximal facial cortices. Space is then created with motorized osteotomes to widen the split ridge. This technique allows for expansion of narrow, anatomically limiting, atrophic ridges, creating space for immediate implant placement. The facial and lingual cortices provide support with vital osteocytes for osteogenesis. The 2 patients presented had adequate bone height for implant placement but narrow edentulous ridges. In patient 1 at site #11, the ridge crest was 3.12 mm thick and was expanded to accept a 4.3 mm × 13 mm implant. The resulting ridge width was 8.88 mm, which was verified using cone beam computerized tomography (CBCT). In patient 2 at site #8 and site #9, the narrow ridge was expanded using the same technique to accept 2 adjacent 3.5 mm × 14 mm implants. The implants were restored to a functional and esthetic outcome.

A Frequency-Domain Substructure System Identification Algorithm

NASA Technical Reports Server (NTRS)

Blades, Eric L.; Craig, Roy R., Jr.

1996-01-01

A new frequency-domain system identification algorithm is presented for system identification of substructures, such as payloads to be flown aboard the Space Shuttle. In the vibration test, all interface degrees of freedom where the substructure is connected to the carrier structure are either subjected to active excitation or are supported by a test stand with the reaction forces measured. The measured frequency-response data is used to obtain a linear, viscous-damped model with all interface-degree of freedom entries included. This model can then be used to validate analytical substructure models. This procedure makes it possible to obtain not only the fixed-interface modal data associated with a Craig-Bampton substructure model, but also the data associated with constraint modes. With this proposed algorithm, multiple-boundary-condition tests are not required, and test-stand dynamics is accounted for without requiring a separate modal test or finite element modeling of the test stand. Numerical simulations are used in examining the algorithm's ability to estimate valid reduced-order structural models. The algorithm's performance when frequency-response data covering narrow and broad frequency bandwidths is used as input is explored. Its performance when noise is added to the frequency-response data and the use of different least squares solution techniques are also examined. The identified reduced-order models are also compared for accuracy with other test-analysis models and a formulation for a Craig-Bampton test-analysis model is also presented.

Deposition Profile Analysis from DIII-D Metal Rings Campaign Outer-Midplane Collector Probe Diagnostic and Utilization of Enriched Isotopic Tungsten Tracer Particles

NASA Astrophysics Data System (ADS)

Donovan, D. C.; Duran, J.; Zamperini, S.; Lee, S.; Unterberg, E. A.; Wampler, W. R.; Rudakov, D. L.; Elder, D.; Stangeby, P. C.; Abrams, T.

2017-10-01

The DIII-D Metal Rings Campaign used isotopically-enriched, W-coated divertor tiles coupled with dual-facing midplane collector probes (CPs) in the far Scrape-off Layer (SOL). Inductively Coupled Plasma Mass Spectroscopy (ICP-MS) results are presented characterizing the isotopic ratios of deposited W on the CPs and which give quantitative information on the transport of W from specific poloidal locations within the lower outer divertor region having different isotopically-marked tiles. Rutherford Backscattering Spectrometry (RBS) of these CPs has provided areal densities of elemental W content. These resultant W deposition profiles were compared with DIVIMP modelling of the far-SOL to better understand impurity transport in the edge plasma. CPs were exposed for 37 distinct operating configurations (L-mode/H-mode, forward/reverse Bt, strikepoint position). Radial decay lengths (RDL) between 5 and 50 mm were observed with consistently narrower RDL and higher peak W content on the side of the probes connected along field lines to the inner divertor, indicating a concentration of W in the upstream plasma. Correlations are discussed between peak W content, RDL, and isotopic profiles on the CPs over a wide range of conditions. Work supported by US DOE under DE-AC05-00OR22725, DE-FG02-07ER54917, DE-FC02-04ER54698, DE-NA0003525.

Galaxy Formation through Filamentary Accretion at z = 6.1

NASA Astrophysics Data System (ADS)

Jones, G. C.; Willott, C. J.; Carilli, C. L.; Ferrara, A.; Wang, R.; Wagg, J.

2017-08-01

We present Atacama Large Millimeter/submillimeter Array observations of the dust continuum and [C II] 158 μm line emission from the z = 6.0695 Lyman-Break Galaxy (LBG) WMH5. These observations at 0.″3 spatial resolution show a compact (˜3 kpc) main galaxy in dust and [C II] emission, with a “tail” of emission extending to the east by about 5 kpc (in projection). The [C II] tail is comprised predominantly of two distinct sub-components in velocity, separated from the core by ˜100 and 250 km s-1, with narrow intrinsic widths of about 80 km s-1, which we call “sub-galaxies.” The sub-galaxies themselves are extended east-west by about 3 kpc in individual channel images. The [C II] tail joins smoothly into the main galaxy velocity field. The [C II] line to continuum ratios are comparable for the main and sub-galaxy positions, within a factor two. In addition, these ratios are comparable to z˜ 5.5 LBGs. We conjecture that the WMH5 system represents the early formation of a galaxy through the accretion of smaller satellite galaxies, embedded in a smoother gas distribution, along a possibly filamentary structure. The results are consistent with current cosmological simulations of early galaxy formation and support the idea of very early enrichment with dust and heavy elements of the accreting material.

High-resolution compact shear stress sensor for direct measurement of skin friction in fluid flow

NASA Astrophysics Data System (ADS)

Xu, Muchen; Kim, Chang-Jin ``Cj''

2015-11-01

The high-resolution measurement of skin friction in complex flows has long been of great interest but also a challenge in fluid mechanics. Compared with indirect measurement methods (e.g., laser Doppler velocimetry), direct measurement methods (e.g., floating element) do not involve any analogy and assumption but tend to suffer from instrumentation challenges, such as low sensing resolution or misalignments. Recently, silicon micromachined floating plates showed good resolution and perfect alignment but were too small for general purposes and too fragile to attach other surface samples repeatedly. In this work, we report a skin friction sensor consisting of a monolithic floating plate and a high-resolution optical encoder to measure its displacement. The key for the high resolution is in the suspension beams, which are very narrow (e.g., 0.25 mm) to sense small frictions along the flow direction but thick (e.g., 5 mm) to be robust along all other directions. This compact, low profile, and complete sensor is easy to use and allows repeated attachment and detachment of surface samples. The sheer-stress sensor has been tested in water tunnel and towing tank at different flow conditions, showing high sensing resolution for skin friction measurement. Supported by National Science Foundation (NSF) (No. 1336966) and Defense Advanced Research Projects Agency (DARPA) (No. HR0011-15-2-0021).

In vivo degradation effects of alloy MgNd2 in contact with mucous tissue.

PubMed

Seitz, J-M; Eifler, R; Weber, C; Lenarz, Th; Maier, H J; Durisin, M

2014-12-10

Magnesium alloys are currently being investigated for use as resorbable bio-materials. Various applications for magnesium based implant materials have already been presented. Currently, stents and structures that sustain diseased or narrowed vessels seem to be the most promising areas. This study focuses on the use of a magnesium fluoride (MgF 2 ) coated magnesium neodymium based alloy (MgNd2) and its use as a post-surgery stent material to avoid proliferation in the sinus region. Simple cylindrical shaped specimens were sewn to the sinus' mucosa of pigs and left in place for different periods of time to investigate the long-term corrosion resistance of the alloy and its coating during direct contact with physiological tissue. Investigations made within this study explicitly focused on the corrosive behavior of the alloy in the region of a physiological sinus. Thus, losses in mass and volume, and element analyses were considered to obtain information about the specimens' corrosion performance over time. Furthermore, micrographs support the alloy specific corrosion type analyses which focus on grain boundary effects. This study demonstrates the general in vivo applicability of fluoride coated MgNd2. The progress of corrosion was determined to be adequate and homogeneous over a total period of 180 days. This article is protected by copyright. All rights reserved. Copyright © 2014 Wiley Periodicals, Inc., A Wiley Company.

REACTOR CONTROL DEVICE

DOEpatents

Kaufman, H.B.; Weiss, A.A.

1959-08-18

A shadow control device for controlling a nuclear reactor is described. The device comprises a series of hollow neutron-absorbing elements arranged in groups, each element having a cavity for substantially housing an adjoining element and a longitudinal member for commonly supporting the groups of elements. Longitudinal actuation of the longitudinal member distributes the elements along its entire length in which position maximum worth is achieved.

45 CFR 1356.83 - Reporting requirements and data elements.

Code of Federal Regulations, 2014 CFR

2014-10-01

... specifically designed instruction, at no cost to parents, to meet the unique needs of a child with a disability... element must be left blank. (21) Academic support. Academic supports are services designed to help a youth... are services designed to help a youth enter or complete a post-secondary education and include the...