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Sample records for fish ladder design

  1. Selectivity of fish ladders: a bottleneck in Neotropical fish movement

    Carlos Sérgio Agostinho

    Full Text Available Although dozens of fish ladders have been constructed at dams of Brazilian reservoirs, there are few studies evaluating their efficiency as a tool for the conservation of Neotropical ichthyofauna, especially for migratory species. Therefore, the present study evaluated the selectivity of the species that entered and ascended the fish ladder located next to Lajeado Dam (Luis Eduardo Magalhães Hydroelectric Power Plant on the Tocantins River. Samples were taken monthly from November, 2002 through October, 2003, in the resting pools of the ladder, using cast nets, and in the downstream stretch, using gillnets. The selectivity of the ladder in attracting fish was evaluated by comparing the occurrence, relative abundance, dominance and the congruence of abundance ranks of migratory and non-migratory species in the ladder and in the stretch of river immediately downstream. Species richness and fish abundance in the resting pools were used to evaluate selectivity along the ladder. The effects on selectivity by temporal variations in water level downriver and maximum flow velocity in the fish ladder were also analyzed. Out of the 130 species recorded downriver, 62.3% were caught in the ladder, and migratory species were clearly favored. However, more than 2/3 of the catch belonged to only three species (Rhaphiodon vulpinus, Psectrogaster amazonica and Oxydoras niger. Although the majority of the species that entered the ladder were able to reach its top, there was a sharp reduction in abundance of individuals towards the top. Temporal variations in the water level below the dam influenced richness and abundance of fish concentrated downstream and in the ladder, with lower values during periods of low water. In the ladder, a maximum flow velocity of 2.3 m/s, although also selective, proved to be more appropriate for fish ascension than a velocity of 2.8 m/s. It was concluded that the entry and ascension of the fish in the ladder were not congruent with

  2. New Concepts in Fish Ladder Design, Volume III of IV, Assessment of Fishway Development and Design, 1982-1983 Final Report.

    Powers, Patrick D.; Orsborn, John F.

    1985-08-01

    This volume covers the broad, though relatively short, historical basis for this project. The historical developments of certain design features, criteria and research activities are traced. Current design practices are summarized based on the results of an international survey and interviews with agency personnel and consultants. The fluid mechanics and hydraulics of fishway systems are discussed. Fishways (or fishpasses) can be classified in two ways: (1) on the basis of the method of water control (chutes, steps (ladders), or slots); and (2) on the basis of the degree and type of water control. This degree of control ranges from a natural waterfall to a totally artificial environment at a hatchery. Systematic procedures for analyzing fishways based on their configuration, species, and hydraulics are presented. Discussions of fish capabilities, energy expenditure, attraction flow, stress and other factors are included.

  3. Selectivity of fish ladders: a bottleneck in Neotropical fish movement

    Carlos Sérgio Agostinho

    2007-01-01

    Full Text Available Although dozens of fish ladders have been constructed at dams of Brazilian reservoirs, there are few studies evaluating their efficiency as a tool for the conservation of Neotropical ichthyofauna, especially for migratory species. Therefore, the present study evaluated the selectivity of the species that entered and ascended the fish ladder located next to Lajeado Dam (Luis Eduardo Magalhães Hydroelectric Power Plant on the Tocantins River. Samples were taken monthly from November, 2002 through October, 2003, in the resting pools of the ladder, using cast nets, and in the downstream stretch, using gillnets. The selectivity of the ladder in attracting fish was evaluated by comparing the occurrence, relative abundance, dominance and the congruence of abundance ranks of migratory and non-migratory species in the ladder and in the stretch of river immediately downstream. Species richness and fish abundance in the resting pools were used to evaluate selectivity along the ladder. The effects on selectivity by temporal variations in water level downriver and maximum flow velocity in the fish ladder were also analyzed. Out of the 130 species recorded downriver, 62.3% were caught in the ladder, and migratory species were clearly favored. However, more than 2/3 of the catch belonged to only three species (Rhaphiodon vulpinus, Psectrogaster amazonica and Oxydoras niger. Although the majority of the species that entered the ladder were able to reach its top, there was a sharp reduction in abundance of individuals towards the top. Temporal variations in the water level below the dam influenced richness and abundance of fish concentrated downstream and in the ladder, with lower values during periods of low water. In the ladder, a maximum flow velocity of 2.3 m/s, although also selective, proved to be more appropriate for fish ascension than a velocity of 2.8 m/s. It was concluded that the entry and ascension of the fish in the ladder were not congruent with

  4. New Concepts in Fish Ladder Design, Part I of IV, Summary Report, 1982-1984 Final Project Report.

    Orsborn, John F.

    1985-08-01

    The report looks at the most active periods of fishway research since 1938 as background for a project to apply fundamental fluid and bio-mechanics to fishway design, and develop more cost effective fish passage facilities with primary application to small scale hydropower facilities. Also discussed are new concepts in fishway design, an assessment of fishway development and design, and an analysis of barriers to upstream migration. (ACR)

  5. Fish ladders: safe fish passage or hotspot for predation?

    Angelo Antonio Agostinho

    2012-10-01

    Full Text Available Fish ladders are a strategy for conserving biodiversity, as they can provide connectivity between fragmented habitats and reduce predation on shoals that accumulate immediately below dams. Although the impact of predation downstream of reservoirs has been investigated, especially in juvenile salmonids during their downstream movements, nothing is known about predation on Neotropical fish in the attraction and containment areas commonly found in translocation facilities. This study analysed predation in a fish passage system at the Lajeado Dam on the Tocantins River in Brazil. The abundance, distribution, and the permanence (time spent of large predatory fish along the ladder, the injuries imposed by piranhas during passage and the presence of other vertebrate predators were investigated. From December 2002 to October 2003, sampling was conducted in four regions (downstream, along the ladder, in the forebay, and upstream of the reservoir using gillnets, cast nets and counts or visual observations. The captured fish were tagged with thread and beads, and any mutilations were registered. Fish, birds and dolphins were the main predator groups observed, with a predominance of the first two groups. The entrance to the ladder, in the downstream region, was the area with the highest number of large predators and was the only region with relevant non-fish vertebrates. The main predatory fish species were Rhaphiodon vulpinus, Hydrolycus armatus, and Serrasalmus rhombeus. Tagged individuals were detected predating along the ladder for up to 90 days. Mutilations caused by Serrasalmus attacks were noted in 36% of species and 4% of individuals at the top of the ladder. Our results suggested that the high density of fish in the restricted ladder environment, which is associated with injuries suffered along the ladder course and the presence of multiple predator groups with different predation strategies, transformed the fish corridor into a hotspot for

  6. Passage and behaviour of cultured Lake Sturgeon in a prototype side-baffle fish ladder: I. Ladder hydraulics and fish ascent

    Kynard, B.; Pugh, D.; Parker, T.

    2011-01-01

    Research and development of a fish ladder for sturgeons requires understanding ladder hydraulics and sturgeon behaviour in the ladder to insure the ladder is safe and provides effective passage. After years of research and development, we designed and constructed a full-scale prototype side-baffle ladder inside a spiral flume (38.3m long??1m wide??1m high) on a 6% (1:16.5) slope with a 1.92-m rise in elevation (bottom to top) to test use by sturgeons. Twenty-eight triangular side baffles, each extending part way across the flume, alternated from inside wall to outside wall down the ladder creating two major flow habitats: a continuous, sinusoidal flow down the ladder through the vertical openings of side-baffles and an eddy below each side baffle. Ascent and behaviour was observed on 22 cultured Lake Sturgeon=LS (Acipenser fulvescens) repeatedly tested in groups as juveniles (as small as 105.1cm TL, mean) or as adults (mean TL, 118cm) during four periods (fall 2002 and 2003; spring 2003 and 2007). Percent of juveniles entering the ladder that ascended to the top was greater in spring (72.7%) than in fall (40.9-45.5%) and 90.9% of 11 adults, which ascended as juveniles, ascended to the top. Six LS (27.3%) never swam to the top and seven (31.8%) swam to the top in all tests, indicating great variability among individuals for ascent drive. Some LS swam directly to the top in mean velocity, 1.2ms-1) swam at 1.8-2.2body lengthss-1 and 3.2-3.3tail beatss-1, either at or approaching prolonged swimming speed. The side-baffle ladder was stream-like and provided key factors for a sturgeon ladder: a continuous flow and no full cross-channel walls, abundant eddies for resting, an acceptable water depth, and a water velocity fish could ascend swimming 2bls-1. A side-baffle ladder passes LS and other moderate-swimming fishes. ?? 2011 Blackwell Verlag, Berlin.

  7. Design and Realization of Numerical Control Ladder Diagram Edition Software

    ZHAO Haixin; MO Yimin; PAN Yunping

    2006-01-01

    The thesis is directed by the idea of oriented- object. Considering the basic functions that NC system Ladder Diagram editor should provide, and through theoretical research and practice, the thesis developed a set of NC system Ladder Diagram editor which can form a Ladder Diagram editor based on vector plotting, intelligently compiling, simulation. This system uses the ladder diagram symbol to express operational order and use the chart symbol series-parallel connection and the position order to express the logical relations between the operational orders, divide the ladder diagram into four parts: the stave, the line, the row and the part, uses the standard order vessel list vessel of the standard template stack (STL) to save the data which involved in the design process. This system can write PLC program by ladder diagram language and is easy to use. The compilation and simulation for PLC diagram have been achieved. It greatly improves the work-efficiency.

  8. New Concepts in Fish Ladder Design: Analysis of Barriers to Upstream Fish Migration, Volume IV of IV, Investigation of the Physical and Biological Conditions Affecting Fish Passage Success at Culverts and Waterfalls, 1982-1984 Final Report.

    Powers, Patrick D.; Orsborn, John F.

    1985-08-01

    A synopsis of the project components was prepared to provide an overview for persons who are not fisheries scientists or engineers. This short report can be used also by technical persons who are interested in the scope of the project, and as a summary of the three main reports. The contents includes an historical perspective on fishway design which provides the basis for this project. The major project accomplishments and significant additions to the body of knowledge about the analysis and design of fishways are discussed. In the next section the research project organization, objectives and components are presented to familiarize the reader with the scope of this project. The summary report concludes with recommendations for assisting in the enhancement and restoration of fisheries resources from the perspective of fish passage problems and their solution. Promising research topics are included.

  9. Ladder Arrangement Method for Stealth Design of Vivaldi Antenna Array

    XiaoXiang He

    2013-01-01

    Full Text Available A novel stealth design method for X-band Vivaldi antenna arrays is proposed in this paper by ladder arrangement along radiation direction. Two-element array, eight-element array, and 3 × 7-element array are investigated in this paper. S parameters, RCSs, and radiation patterns are studied, respectively. According to the ladder arrangement of Vivaldi antennas presented, 16.3 dBsm maximal RCS reduction is achieved with satisfied radiation performance. As simulated and measured, results demonstrate that the effectiveness of the presented low RCS design method is validated.

  10. Improved Design Techniques for Switched-Capacitor Ladder Filters.

    Hsu, Teng-Hsien

    Using the new developments of MOS technology, switched-capacitor filters which consist of operational amplifiers, capacitors and switches in monolithic form, were widely investigated and put into practical forms. The switched-capacitor ladder filters have derived from doubly-terminated reactance two-ports. The main part of this dissertation is aimed at improving the efficiency and eliminating some shortcomings of the bilinear design technique. Two novel input stages which incorporate the necessary sample-and-hold function into the bilinear ladder filters are presented. The circuits are insensitive to parasitic capacitances. Some techniques to reduce the number of operational amplifier for bilinear switched-capacitor ladder filters are given. The number of top-plate parasitic-sensitive capacitors is less than in any of the existing design techniques. The clock feedthrough effects of pseudo-N-path switched-capacitor filter using lowpass filters as path filters are eliminated by the improved technique with doubling the number of operational amplifiers. Two-phase pseudo -N-path switched-capacitor filters can be obtained by tripling the number of operational amplifiers. The design technique for extending bilinear lowpass switched-capacitor ladder filters from odd orders to even orders is presented. One of the factors limiting the speed of bilinear switched-capacitor ladder filters is the delay-free loops. The techniques for breaking delay-free loops of low-order switched -capacitor filters are introduced. Digital ladder filters can be obtained through those switched-capacitor filters without delay-free loops. Numerical examples are given to compare the following digital filters: general cascade realization, wave digital filter, the digital filters derived from switched-capacitor filters - cascade and ladder. An improved high speed switched-capacitor linear interpolator, and nonlinear interpolators are described. The circuits are completely parasitic-insensitive. Two

  11. New Concepts in Fish Ladder Design, Volume II of IV, Results of Laboratory and Field Research on New Concepts in Weir and Pool Fishways, 1982-1984 Final Project Report.

    Aaserude, Robert G.; Orsborn, John F.

    1985-08-01

    A comprehensive review of fishway design practice led to new design concepts that had previously been untested. This concept was based on the observation that fish can be stimulated to leap when presented with certain hydraulic conditions. A laboratory test program was conducted to develop this concept into a new fishway configuration. Field testing revealed that components of the new design improved fish passage. Verification of the initial premise that fish can be stimulated to leap needs further study.

  12. Selection of an experimental fish ladder located at the dam of the Itaipu Binacional, Paraná River, Brazil

    Domingo Rodriguez Fernandez

    2004-08-01

    Full Text Available The specific selection of a weir and orifice type experimental fish ladder in the dam of the Itaipu Reservoir (Paraná River was evaluated by samplings in the river downstream and at two points along the ladder (at heights of 10 m and 27 m during 28 months. Among the 65 species recorded in the river (immediate downstream of the dam, 27 were captured on the ladder. The species that showed highest density on the ladder, the majority migratory, were moderately, or only slightly, abundant downstream. Among the most abundant species downstream, only one, non-migratory, was recorded in the ladder. The structure presented a negative selection in relation to large migratory pimelodids that might be overcome by enlarging the scale of its design. The sampling demonstrated a moderate selection of species along the ladder and its hydraulic model proved satisfactory regarding the attraction and efficient ascent of the fishes.A seleção específica de uma escada de peixes do tipo seqüência de tanques, com passagem de fundo (tipo weir and orifice, na barragem da hidrelétrica de Itaipu (rio Paraná, foi avaliada através de amostragens no rio a jusante (amostragem trimestral em 1997 e em dois pontos ao longo da escada (10 e 27m de altura; nov/94 a jan/97 e nov/94 a fev/97, respectivamente. Das 65 espécies registradas no rio imediatamente a jusante da barragem, 27 foram capturadas na escada. As espécies com maior densidade na escada, em sua maioria migradoras, tiveram abundância moderada ou baixa a jusante. Entre as mais abundantes a jusante, apenas uma, não migradora, foi registrada na escada. A escada apresentou seleção negativa aos grandes pimelodídeos migradores que pode ser superada com a ampliação na escala do projeto. As amostragens evidenciaram baixa seletividade específica ao longo da escada, sendo seu modelo hidráulico satisfatório na atração e eficiente na ascensão de peixes.

  13. Influence of seasonal, diel, lunar, and other environmental factors on upstream fish passage in the igarapava fish ladder, Brazil

    Bizzotto, P.M.; Godinho, Alexandre L.; Vono, V.; Kynard, B.; Godinho, Hugo P.

    2009-01-01

    Upstream fish passage was evaluated during 12 months in the vertical-slot Igarapava Fish Ladder constructed around Igarapava Dam, in the heavily dammed Grande River, Southeast Brazil. A video monitoring system was used to observe 61,621 fish that passed the ladder, of which 93.5% were identified to 15 taxa. Among the migratory species, the most abundant were Pimelodus maculatus (33.6% of all fish), Leporinus octofasciatus (31.4%), Leporinus friderici (4.5%), and Prochilodus lineatus (3.1%). Seven taxa were classified as nonmigratory, and of these taxa, the small Bryconamericus stramineus was the most abundant (12.7%) of all fishes. Passage of the 'nonmigratory' taxa upstream in the ladder shows they are migratory in this system and have a strong behavioural drive to move to upstream habitat. Passage of most taxa had a strong seasonal pattern. While some species passed primarily during the day, others showed a distinct nocturnal pattern. Lunar phase and water temperature also strongly affected passage of some taxa. Rainfall and dam discharge had a small or null influence on most taxa; perhaps due to the fairly small catchment area of the reservoir and the highly regulated discharge at Igarapava Dam. ?? 2009 John Wiley & Sons A/S.

  14. Design of Dual Bandpass and Bandreject LC Ladder Filters

    J. Hospodka

    2006-09-01

    Full Text Available This paper deals with the design of two-passband bandpass and two-stopband bandreject LC ladder filters. The design method is based on the special dual frequency transformation that transforms normalized lowpass to either bandpass with two passbands or to bandreject with two stopbands that are specified by four cutoff frequencies. The paper shows analytical solution relating these four cutoff frequencies to parameters of dual frequency transformation. It enables a direct computation of dual band LC filter elements from a normalized lowpass filter by means of simple relations. These relations have been implemented in the mathematical program Maple (TM as new user functions. They are supposed to be used as an enhancement of Syntfil package which is intended for analog filter design in program Maple. Specific application is shown on an example of the two-passband bandpass LC filter design.

  15. Design and construction of double-sided silicon ladders for the L3 microvertex detector

    Ambrosi, G.; Babucci, E.; Battiston, R.; Biasini, M.; Easo, S.; Krastev, V.; Pauluzzi, M.; Santocchia, A.; Bay, A.; Burger, W.J.; Extermann, P.; Perrin, E.; Susinno, G.; Brooks, M.; Kapustinsky, J.S.; Kinnison, W.W.; Lee, D.M.; Mills, G.B.; Thompson, T.C.; DiBitonto, D.; Pennington, T.; Subhani, K.; Hauviller, C. (Univ. Degli Studi di Perugia (Italy) INFN, Perugia (Italy) Univ. of Geneva (Switzerland) Los Alamos National Lab., Los Alamos, NM (United States) Univ. of Alabama, Tuscaloosa, AL (United States) European Lab. for Particle Physics (CERN), Geneva (Switzerland))

    1994-04-21

    The techniques used in the construction of the double-sided ladders for the L3 Silicon Microvertex Detector (SMD) are presented. The detector consists of two cylindrical layers, each of 12 ladders, with double-sided silicon detectors which provide r-phi and z coordinates measurements. This description includes ladder mechanical design and the assembly. A novel solution to readout the z-coordinates is presented. It optimizes very effectively the removal of heat generated by the readout electronics and minimizes the radiation length in the central region. Some results from the survey of the individual ladders are also discussed. (orig.)

  16. Design of a 325 MHz ladder - type RFQ for FAIR

    Schuett, Maximilian; Brodhage, Robert; Almomani, Ali; Ratzinger, Ulrich [Institut fuer Angewandte Physik, Goethe-Universitaet Frankfurt, Max-von-Laue-Str. 1, 60438 Frankfurt am Main (Germany)

    2014-07-01

    For the research program with cooled antiprotons at FAIR a dedicated 70 MeV, 70 mA proton injector is required. The first rf accelerator element is a 325 MHz RFQ accelerating from 95 keV to 3.0 MeV. RFQ's beyond 300 MHz were realized in 4-Vane-type geometry so far. At IAP there is a tradition in 4-Rod-type RFQ development. This RFQ-type is dominating at lower frequencies. Very promising results have been reached with a ladder type-RFQ, which has been investigated during 2013. We show most recent 3D simulations of the general layout and of a whole cavity demonstrating the power of a ladder type RFQ. An RFQ layout for the new FAIR proton injector is presented. In comparison with a traditional 4-Rod RFQ approach the geometry is more convenient at high frequencies.

  17. Assessments to determine the effect of current and alternate ladder operations on brood stock collection and behavior of hatchery fall Chinook Salmon at Spring Creek National Fish Hatchery during 2003-2005

    US Fish and Wildlife Service, Department of the Interior — Spring Creek National Fish Hatchery traditionally operates an adult ladder, without closure, from the start of the tule fall Chinook salmon run in late August until...

  18. Design and test of the final ALICE SDD CARLOS end ladder board

    Antinori, S; Falchieri, D; Gabrielli, A; Gandolfi, E; Masetti, M; Tosellob, F

    2007-01-01

    The paper presents the design and test of the final prototype of the CARLOS (Compression And Run Length Encoding Subsystem) end ladder board that is going to be used in the ALICE experiment at CERN. This board is able to compress data coming from one Silicon Drift Detector (SDD) front-end electronics and to send them towards the data concentrator card CARLOSrx in counting room via a 800 Mb/s optical link. The board design faces several constraints, mainly size (54x49 mm) and radiation tolerance: for this reason the board contains several CERN developed ASICs. A test setup has been realized for selecting the good devices among the 500 cards already produced.

  19. Theoretical Design of a 104 MHz Ladder Type IH-RFQ Accelerator

    NIE Yuan-Cun; LU Yuan-Rong; CHEN Jia-Er; YAN Xue-Qing; GAO Shu-Li; ZHU Kun; LIU Ke-Xin; GUO Zhi-Yu

    2010-01-01

    @@ Beam dynamics and rf designs of a 104 MHz ladder type IH-RFQ (L-IH-RFQ) accelerator are finished at Peking University for the acceleration of 14C+ from 40 keV to 500 keV. As a specific feature, the output beam energy spread is as low as 0.6% achieved with the internal discrete bunching method, which makes potential applications of RFQ feasible, such as accelerator mass spectrometry and ion implantation. Tolerances of the beam dynamics design are studied by means of changing the input beam parameters, and the results are quite satisfying. On the other hand, the L-IH-RFQ structure is employed, taking advantage of its mechanical stability and the absence of inter-electrode voltage asymmetry. Radio-frequency properties are studied and optimized for reducing power loss with Microwave Studio (MWS). Tuning of the field fiatness and frequency is investigated in principle.

  20. 29 CFR 1910.27 - Fixed ladders.

    2010-07-01

    .... (v) The rungs of an individual-rung ladder shall be so designed that the foot cannot slide off the... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Walking-Working Surfaces § 1910.27 Fixed ladders. (a) Design requirements—(1) Design considerations. All ladders, appurtenances, and fastenings shall be designed to...

  1. Towards Monodisperse Star-Shaped Ladder-Type Conjugated Systems: Design, Synthesis, Stabilized Blue Electroluminescence and Amplified Spontaneous Emission.

    Lai, Wen-Yong; Jiang, Yi; Fang, Mei; Chang, Si-Ju; Huang, Jin-Jin; Chu, Shuang-Quan; Hu, Shan-Ming; Liu, Cheng-Fang; Huang, Wei

    2017-02-14

    A novel series of monodisperse star-shaped ladder-type oligo(p-phenylene)s, named as TrL-n (n = 1-3), have been explored. Their thermal and electrochemical properties, fluorescence transients, photoluminescence quantum yields, density functional theory calculations, electroluminescence (EL) and amplified spontaneous emission (ASE) properties have been systematically investigated to unravel the molecular design on optoelectronic properties. The resulting materials showed excellent structural perfection free of chemical defects, exhibiting great thermal stability (Td: 404-418°C and Tg:147-184°C) and amorphous glassy morphologies. Compared with their corresponding linear counterparts FL-m (m = 1-3), TrL-n showed only little bathochromic shifts (5-12 nm) for the absorption maxima λmax in both solution and films. The star-shaped ladder-type compounds exhibited enhanced optical stability and suppressed low-energy emission. Their EL spectra exhibited excellent stability with increasing the driving voltage from 6 to 12 V. Moreover, superior low ASE thresholds were recorded for TrL-n compared with FL-m. Rather low ASE threshold (29 nJ/pulse or 1.60 μJ/cm2) was recorded for TrL-3, demonstrating their promising potential as excellent gain media. This study provides a novel design concept to develop monodisperse star-shaped ladder-type materials with excellent structural perfection, which are vital for shedding light on exploring robust organic emitters for optoelectronic applications.

  2. Voegelin's Ladder

    Nathan Harter

    2006-06-01

    Full Text Available Leadership has non-logical aspects. One of these is spirituality. Voegelin’s Ladder provides a context for studying spirituality as a part of leadership. What it reveals is that spirituality arises at the intersection of the human with the divine. Spirituality expresses itself as purpose and aspiration, which a leader embodies.

  3. The latrine ownership ladder

    Obeng, Peter Appiah; Keraita, Bernard; Oduro-Kwarteng, Sampson;

    2015-01-01

    Purpose – The purpose of this paper is to present the latrine ownership ladder as a conceptual policy framework to enhance sanitation uptake in low-income peri-urban areas. Design/methodology/approach – The paper draws from literature and a case study in a Ghanaian peri-urban community to highlight...... the challenges that undermine sanitation uptake in low-income peri-urban areas and the prospects of various levels of facility sharing as conceived in the latrine ownership ladder approach. Findings – The authors argue that the infrastructural and other socio-economic challenges of low-income peri-urban areas...... to the promotion of household latrines. The paper identifies provision of special concessions for peri-urban areas in policy formulation, education and technical support to households, regulation and enforcement of sanitation by-laws among complimentary policy interventions to make the latrine ownership ladder...

  4. Novel Zn(II) ladder-like coordination polymer constructed from designed ferrocenyl ligand

    2008-01-01

    Reaction of Zn(NO3)2.6H2O with 3-(4-carboxylphenylamino)-1-ferrocenyl-2-butylen-1-one (HL) and 4,4'-bipyridine (4,4'-bipy) in methanol solution resulted in a novel ladder-like coordination polymer {[Zn2L2(μ2-L)2(4,4'-bipy)2].MeOH}n (1). Its crystal structure, thermal and electrochemical properties axe presented.

  5. Designing and constructing an 100 bp DNA Ladder by combining PCR and enzyme digestion methods

    Saidijam M

    2011-05-01

    Full Text Available "n Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:Arial; mso-bidi-theme-font:minor-bidi;} Background: Molecular DNA markers are one of the most important tools in molecular biology labs. The size of DNA molecules is determined by comparing them with known bands of markers during gel electrophoresis. There are many different protocols to produce these kinds of molecular markers. In this study we have suggested an efficient strategy to produce molecular weight markers in industrial proportions."n"nMethods : To achieve the desired sizes of DNA fragments, a combination of two previously known methods, restriction enzyme digestion and polymerase chain reaction (PCR, were used. The enzymatic digestion process was based on designing and constructing plasmids which equaled in size with the desired length of DNA fragments and produced the desired DNA fragment upon linearization. In the PCR method, the desired length of DNA fragments were cloned in multiple cloning sites of pTZ57R plasmid and in a PCR reaction, the new constructed plasmid was used as a template to produce the final fragment."n"nResults : Upon application of this strategy, 2000 and 3000 bp DNA fragments were produced by enzymatic digestion of plasmids of the same size. Moreover, 100 to 1500 bp fragments were produced during PCR using only a set of

  6. A High Efficiency, Miniaturized Ka Band Traveling Wave Tube Based on a Novel Finned Ladder RF Circuit Design

    Wintucky, E. G.; Wilson, J. D.; Vaden, K. R.; Force, D. A.; Freeman, J. C.; Lesny, G. G.; Kory, C. L.; Chevalier, C. T.; Ebihara, B.; Dayton, J. A.; Williams, W. D. (Technical Monitor)

    2001-01-01

    Space communications architectures are being planned to meet the high rate data distribution requirements of future NASA Enterprise missions. These will require the use of traveling wave tube amplifiers (TWTAs) to provide the high frequency, RF (radio frequency) power and efficiency needed for many of the communications links. A program addressing these requirements is currently underway at NASA Glenn Research Center (GRC) for the development of a high efficiency, 20 watt, 32 GHz TWT of reduced size and weight that is based on a novel high gain n circuit design, termed the 'finned ladder'.

  7. Design of Bunk Bed with Dual-purpose Ladder%学生双层床两用梯的设计

    张西珠; 耿振香

    2016-01-01

    Based on an analysis of the bunk bed in a current student’s dormitory, a dual-purpose ladder of the bunk bed for students is designed to diversity the function of the ladder. This dual-propose ladder is more than a common one, it can be used as a table after being folded up by sliding and flipping. The ladder’s function can be improved as well as a guarantee of security. The designed ladder not only change the understanding of a bunk bed ladder, but also highlight its perfect innovation features.%通过对目前宿舍学生双层床梯子功能的分析,设计出一种新型的学生双层床两用梯。本文不仅介绍了梯子通过滑动和翻转,使两用梯在完成正常梯子功能后,又可折叠当作书桌使用功能;在保证安全性的同时,完成了结构性设计。本设计具有创新特性,让双层床的梯子功能实现了多样化。

  8. Design of Lightweight-style Escape Ladders%轻巧式逃生梯的设计

    袁健

    2011-01-01

    This paper presents a design method of Lightweight-style escape ladders, mainly researches on their functional and structural design and checks them on strength. The product is not only used for escape, but also for drying and other use with the characteristics of no power,no pollution,simple structure,convenient operation,easy manufacture,low cost,safety and reliability.%提出了一种轻巧式选生梯的设计方法.主要进行逃生梯的功能设计和强度校核,介绍了关键结构设计.指出该产品无需电源,无污染,结构简单,操作方便,制造容易,成本低,安全可靠,可以实现速生、晾晒等多种功能.

  9. Design of a reliable PUF circuit based on R-2R ladder digital-to-analog convertor

    Pengjun, Wang; Xuelong, Zhang; Yuejun, Zhang; Jianrui, Li

    2015-07-01

    A novel physical unclonable functions (PUF) circuit is proposed, which relies on non-linear characteristic of analog voltage generated by R-2R ladder DAC. After amplifying the deviation signal, the robustness of the DAC-PUF circuit has increased significantly. The DAC-PUF circuit is designed in TSMC 65 nm CMOS technology and the layout occupies 86.06 × 63.56 μm2. Monte Carlo simulation results show that the reliability of the DAC-PUF circuit is above 98% over a comprehensive range of environmental variation, such as temperature and supply voltage. Project supported by the National Natural Science Foundation of China (Nos. 61474068, 61404076, 61274132), the Zhejiang Provincial Natural Science Foundation of China (No. LQ14F040001), and the K. C. Wong Magna Fund in Ningbo University, China.

  10. Ladder Safety Live #12985

    Chochoms, Michael [Los Alamos National Laboratory

    2017-02-23

    This course presents information for working safely with portable ladders: specifically, stepladders, extensions ladders, and their derivations. Additionally, this course provides limited information on the safe use of stepstools and fixed ladders. The skills, techniques, and good practices needed for selecting, inspecting, setting up and securing, and using ladders are presented in this course.

  11. Design concepts for a high-impedance narrow-band 42 GHz power TWT using a fundamental/forward ladder-based circuit

    Karp, A.

    1980-01-01

    A low-cost, narrowband, millimeter wave space communications TWT design was studied. Cold test interaction structure scale models were investigated and analyses were undertaken to predict the electrical and thermal response of the hypothetical 200 W TWT at 42 GHz and 21 kV beam voltage. An intentionally narrow instantaneous bandwidth (1%, with the possibility of electronic tuning of the center frequency over several percent) was sought with a highly dispersive, high impedance "forward wave' interaction structure based on a ladder (for economy in fabrication) and nonspace harmonic interaction, for a high gain rate and a short, economically focused tube. The "TunneLadder' interaction structure devised combines ladder properties with accommodation for a pencil beam. Except for the impedance and bandwidth, there is much in common with the millimeter wave helix TWTs which provided the ideal of diamond support rods. The benefits of these are enhanced in the TunneLadder case because of spatial separation of beam interception and RF current heating.

  12. Understanding the Behaviour of Infinite Ladder Circuits

    Ucak, C.; Yegin, K.

    2008-01-01

    Infinite ladder circuits are often encountered in undergraduate electrical engineering and physics curricula when dealing with series and parallel combination of impedances, as a part of filter design or wave propagation on transmission lines. The input impedance of such infinite ladder circuits is derived by assuming that the input impedance does…

  13. Hood River and Pelton Ladder Monitoring and Evaluation Project and Hood River Fish Habitat Project : Annual Progress Report 1999-2000.

    Lambert, Michael B.; McCanna, Joseph P.; Jennings, Mick

    2001-02-01

    The Hood River subbasin is home to four species of anadromous salmonids: chinook salmon (Oncorhynchus tshawytscha), coho salmon (Oncorhynchus kisutch), steelhead (Oncorhynchus mykiss), and sea run cutthroat trout (Salmo clarki). Indigenous spring chinook salmon were extirpated during the late 1960's. The naturally spawning spring chinook salmon currently present in the subbasin are progeny of Deschutes stock. Historically, the Hood River subbasin hatchery steelhead program utilized out-of-basin stocks for many years. Indigenous stocks of summer and winter steelhead were listed in March 1998 by National Marine Fisheries Service (NMFS) under the Endangered Species Act (ESA) as a ''Threatened'' Species along with similar genetically similar steelhead in the Lower Columbia Basin. This annual report summarizes work for two consecutive contract periods: the fiscal year (FY) 1999 contract period was 1 October, 1998 through 30 September, 1999 and 1 October, 1999 through 30 September, 2000 for FY 2000. Work implemented during FY 1999 and FY 2000 included (1) acclimation of hatchery spring chinook salmon and hatchery summer and winter steelhead smolts, (2) spring chinook salmon spawning ground surveys on the West Fork Hood River (3) genetic analysis of steelhead and cutthroat [contractual service with the ODFW], (4) Hood River water temperature studies, (5) Oak Springs Hatchery (OSH) and Round Butte Hatchery (RBH) coded-wire tagging and clipping evaluation, (6) preparation of the Hood River Watershed Assessment (Coccoli et al., December 1999) and the Fish Habitat Protection, Restoration, and Monitoring Plan (Coccoli et al., February 2000), (7) project implementation of early action habitat protection and restoration projects, (8) Pelton Ladder evaluation studies, (9) management oversight and guidance to BPA and ODFW engineering on HRPP facilities, and (10) preparation of an annual report summarizing project objectives for FY 1999 and FY 2000.

  14. Detecting Cerebellar Phenotypes with the Erasmus Ladder

    A. Cupido (Alexander)

    2009-01-01

    textabstractI designed, created and established a new motor behavioural task for mice, the Erasmus Ladder. It is now a quick and reliable behavioural task to determine if (mutant) mice could be a good model for a neurological disease.

  15. Experimental evidence of variable-order behavior of ladders and nested ladders

    Sierociuk, Dominik; Petras, Ivo

    2011-01-01

    The experimental study of two kinds of electrical circuits, a domino ladder and a nested ladder, is presented. While the domino ladder is known and already appeared in the theory of fractional-order systems, the nested ladder circuit is presented in this article for the first time. For fitting the measured data, a new approach is suggested, which is based on using the Mittag-Leffler function and which means that the data are fitted by a solution of an initial-value problem for a two-term fractional differential equation. The experiment showed that in the frequency domain the domino ladder behaves as a system of order 0.5 and the nested ladder as a system of order 0.25, which is in perfect agreement with the theory developed for their design. In the time domain, however, the order of the domino ladder is changing from roughly 0.5 to almost 1, and the order of the nested ladder is changing in a similar manner, from roughly 0.25 to almost 1; in both cases, the order 1 is never reached, and both systems remain th...

  16. Ladder attachment platform

    Swygert,; Richard, W [Springfield, SC

    2012-08-28

    A ladder attachment platform is provided that includes a base for attachment to a ladder that has first and second side rails and a plurality of rungs that extend between in a lateral direction. Also included is a user platform for having a user stand thereon that is carried by the base. The user platform may be positioned with respect to the ladder so that it is not located between a first plane that extends through the first side rail and is perpendicular to the lateral direction and a second plane that extends through the second side rail and is perpendicular to the lateral direction.

  17. Mechanical design and implementation of a new biomimetic robot fish

    Wang Long; Cao Zhiqiang; Tan Min; Wang Shuo

    2007-01-01

    A mechanical design method of robot fish is introduced in this paper.Based on this method an antonomous 3-Dimension(3D)locomotion robot fish with two pectoral fins and a caudal fin is developed.The pectoral fin mechanism has 3 degrees of freedom(3-DOFs),which enables the robot fish to realize yawing and pitching motions by controlling two pectoral fins.And the caudal fin mechanism is designed based on fish body wave curve fitting.The forward velocity can be adjusted by changing the caudal mechanism's oscillating frequency.Finally a physical implementation of the robot fish and experimental results are given.

  18. Fish Protection: Cooperative research advances fish-friendly turbine design

    Brown, Richard S.; Ahmann, Martin L.; Trumbo, Bradly A.; Foust, Jason

    2012-12-01

    Renewable hydropower is a tremendous resource within the Pacific Northwest that is managed with considerable cost and consideration for the safe migration of salmon. Recent research conducted in this region has provided results that could lower the impacts of hydro power production and make the technology more fish-friendly. This research is now being applied during a period when a huge emphasis is being made to develop clean, renewable energy sources.

  19. Theory of Double Ladder Lumped Circuits With Degenerate Band Edge

    Sloan, Jeff; Capolino, Filippo

    2016-01-01

    Conventional periodic LC ladder circuits exhibit a regular band edge between a pass and a stop band. Here for the first time we develop the theory of simple yet unconventional double ladder circuits exhibiting a special degeneracy condition referred to as degenerate band edge (DBE). This special DBE condition is associated with four independent eigenstates of the double ladder that coalesce into a single one when the operative frequency coincides with the DBE one. In particular, we show that double ladder resonators may exhibit giant loaded quality factor near the DBE and stable resonance frequency against load variations. These two properties in the proposed circuit are superior to the analogous properties in single ladder circuits. Our proposed analysis leads to analytic expressions for all circuit quantities thus providing insight into the very complex behavior near points of degeneracy in periodic circuits; and provides a design procedure for the use of such double ladder in practical applications. Intere...

  20. Novel high-gain, improved-bandwidth, finned-ladder V-band Traveling-Wave Tube slow-wave circuit design

    Kory, Carol L.; Wilson, Jeffrey D.

    1994-01-01

    The V-band frequency range of 59-64 GHz is a region of the millimeter-wave spectrum that has been designated for inter-satellite communications. As a first effort to develop a high-efficiency V-band Traveling-Wave Tube (TWT), variations on a ring-plane slow-wave circuit were computationally investigated to develop an alternative to the more conventional ferruled coupled-cavity circuit. The ring-plane circuit was chosen because of its high interaction impedance, large beam aperture, and excellent thermal dissipation properties. Despite these advantages, however, low bandwidth and high voltage requirements have, until now, prevented its acceptance outside the laboratory. In this paper, the three-dimensional electrodynamic simulation code MAFIA (solution of MAxwell's Equation by the Finite-Integration-Algorithm) is used to investigate methods of increasing the bandwidth and lowering the operating voltage of the ring-plane circuit. Calculations of frequency-phase dispersion, beam on-axis interaction impedance, attenuation and small-signal gain per wavelength were performed for various geometric variations and loading distributions of the ring-plane TWT slow-wave circuit. Based on the results of the variations, a circuit termed the finned-ladder TWT slow-wave circuit was designed and is compared here to the scaled prototype ring-plane and a conventional ferruled coupled-cavity TWT circuit over the V-band frequency range. The simulation results indicate that this circuit has a much higher gain, significantly wider bandwidth, and a much lower voltage requirement than the scaled ring-plane prototype circuit, while retaining its excellent thermal dissipation properties. The finned-ladder circuit has a much larger small-signal gain per wavelength than the ferruled coupled-cavity circuit, but with a moderate sacrifice in bandwidth.

  1. Ladder Variational Autoencoder

    Sønderby, Casper Kaae; Raiko, Tapani; Maaløe, Lars

    2016-01-01

    Variational autoencoders are powerful models for unsupervised learning. However deep models with several layers of dependent stochastic variables are difficult to train which limits the improvements obtained using these highly expressive models. We propose a new inference model, the Ladder Variat...

  2. Ladders to Success.

    Hersch, Paul

    1982-01-01

    The Metropolitan Sewerage District (Green Bay, Wisconsin) has developed a reputation as a well-engineered, competently managed, and efficiently operated facility. Describes management devices to foster positive employee attitudes (human resources development plan, career ladders), money-wise approaches used by the facility, and new developments…

  3. Design and testing of small scale fish meat bone separator useful for fish processing.

    Ali Muhammed, M; Manjunatha, N; Murthy, K Venkatesh; Bhaskar, N

    2015-06-01

    The present study relates to the food processing machinery and, more specifically machine for producing boneless comminuted meat from raw fish fillet. This machine is of belt and drum type meat bone separator designed for small scale fish processing in a continuous mode. The basic principal involved in this machine is compression force. The electric geared motor consists of 1HP and the conveyor belt has a linear velocity of 19 to 22 m min(-1), which was sufficient to debone the fish effectively. During the meat bone separation trials an efficiency up to 75 % on dressed fish weight basis was observed and with a capacity to separate 70 kg h(-1) of meat from fish at the machine speed of 25 rpm. During the trials, it was demonstrated that there was no significant change in the proximate composition of comminuted fish meat when compared to unprocessed fish meat. This design has a greater emphasis on hygiene, provision for cleaning-in-place (CIP) and gives cost effective need and reliability for small scale industries to produce fish meat in turn used for their value added products.

  4. Design of a re-entrant double-staggered ladder circuit for V-band coupled-cavity traveling-wave tubes

    Liu Yang; Xu Jin; Lai Jian-Qiang; Xu Xiong; Shen Fei; Wei Yan-Yu; Huang Min-Zhi; Tang Tao; Gong Yu-Bin

    2012-01-01

    The re-entrant double-staggered ladder slow-wave structure is employed in a high-power V-band coupled-cavity traveling-wave tube.This structure has a wide bandwidth,a moderate interaction impedance,and excellent thermal dissipation properties,as well as easy fabrication.A well-matched waveguide coupler is proposed for the structure.Combining the design of attenuators,a full-scale three-dimensional circuit model for the V-band coupled-cavity travelingwave tube is constructed.The electromagnetic characteristics and the beam-wave interaction of this structure are investigated.The beam current is set to be 100 mA,and the cathode voltage is tuned from 16.8 kV to 15.8 kV.The calculation results show that this tube can produce a saturated average output power over 100 W with an instantaneous bandwidth greater than 1.25 GHz in the frequency ranging from 58 GHz to 62 GHz.The corresponding gain and electronic efficiency can reach over 32 dB and 6.5%,respectively.

  5. Biologically Inspired Behaviour Design for Autonomous Robotic Fish

    Jin-Dong Liu; Huosheng Hu

    2006-01-01

    Behaviour-based approach plays a key role for mobile robots to operate safely in unknown or dynamically changing environments. We have developed a hybrid control architecture for our autonomous robotic fish that consists of three layers: cognitive, behaviour and swim pattern. In this paper, we describe some main design issues of the behaviour layer, which is the centre of the layered control architecture of our robotic fish. Fuzzy logic control (FLC) is adopted here to design individual behaviours. Simulation and real experiments are presented to show the feasibility and the performance of the designed behaviour layer.

  6. Optimal design and motion control of biomimetic robotic fish

    YU JunZhi; WANG Long; ZHAO Wei; TAN Min

    2008-01-01

    This paper is concerned with the design, optimization, and motion control of a radio-controlled, multi-link, free-swimming biomimetic robotic fish based on an opti-mized kinematic and dynamic model of fish swimming. The performance of the robotic fish is determined by both the fish's morphological characteristics and ki-nematic parameters. By applying ichthyologic theories of propulsion, a design framework that takes into consideration both mechatronic constraints in physical realization and feasibility of control methods is presented, under which a multiple linked robotic fish that integrates both the carangiform and anguilliform swimming modes can be easily developed. Taking account of both theoretic hydrodynamic issues and practical problems in engineering realization, the optimal link-length-ratios are numerically calculated by an improved constrained cyclic variable method, which are successfully applied to a series of real robotic fishes. The rhythmic movements of swimming are driven by a central pattern generator (CPG) based on nonlinear oscillations, and up-and-down motion by regulating the rotating angle of pectoral fins. The experimental results verify that the presented scheme and method are effective in design and implementation.

  7. Bioinspiration from fish for smart material design and function

    Lauder, G. V.; Madden, P. G. A.; Tangorra, J. L.; Anderson, E.; Baker, T. V.

    2011-09-01

    Fish are a potentially rich source of inspiration for the design of smart materials. Fish exemplify the use of flexible materials to generate forces during locomotion, and a hallmark of fish functional design is the use of body and fin deformation to power propulsion and maneuvering. As a result of nearly 500 million years of evolutionary experimentation, fish design has a number of interesting features of note to materials engineers. In this paper we first provide a brief general overview of some key features of the mechanical design of fish, and then focus on two key properties of fish: the bilaminar mechanical design of bony fish fin rays that allows active muscular control of curvature, and the role of body flexibility in propulsion. After describing the anatomy of bony fish fin rays, we provide new data on their mechanical properties. Three-point bending tests and measurement of force inputs to and outputs from the fin rays show that these fin rays are effective displacement transducers. Fin rays in different regions of the fin differ considerably in their material properties, and in the curvature produced by displacement of one of the two fin ray halves. The mean modulus for the proximal (basal) region of the fin rays was 1.34 GPa, but this varied from 0.24 to 3.7 GPa for different fin rays. The distal fin region was less stiff, and moduli for the different fin rays measured varied from 0.11 to 0.67 GPa. These data are similar to those for human tendons (modulus around 0.5 GPa). Analysis of propulsion using flexible foils controlled using a robotic flapping device allows investigation of the effect of altering flexural stiffness on swimming speed. Flexible foils with the leading edge moved in a heave show a distinct peak in propulsive performance, while the addition of pitch input produces a broad plateau where the swimming speed is relatively unaffected by the flexural stiffness. Our understanding of the material design of fish and the control of tissue

  8. Six-Degree-of-Freedom Sensor Fish Design and Instrumentation

    Marshall C. Richmond

    2007-11-01

    Full Text Available Fish passing through dams may be injured or killed despite advances in turbinedesign, project operations and other fish bypass systems. The six-degree-of-freedom (6DOFSensor Fish device is an autonomous sensor package that characterizes the physical conditionsand physical stresses to which fish are exposed when they pass through complex hydraulicenvironments. It has been used to identify the locations and operations where conditions aresevere enough to injure or kill fish. During the design process, a set of governing equationsof motion for the Sensor Fish was derived and simulated to understand the design implica-tions of instrument selection and placement within the body of the device. The Sensor Fishpackage includes three rotation sensors, three acceleration sensors, a pressure sensor, and atemperature sensor with a sampling frequency of 2,000 Hz. Its housing is constructed of clearpolycarbonate plastic. It is 24.5 mm in diameter and 90 mm in length and weighs about 43 g,similar to the size and density of a yearling salmon smolt. The accuracy of the pressure sensorwas determined to be within 0.2 psi. In laboratory acceptance tests, the relative errors of boththe linear acceleration and angular velocity measurements were determined to be less than5%. An exposure is defined as a significant event when the acceleration reaches predefinedthresholds. Based on the different characteristic of acceleration and rotation velocities, theexposure event is categorized as either a collision between the Sensor Fish and a solid struc-ture or shear caused by turbulence. Since its development in 2005, the 6DOF Sensor Fish hasbeen deployed successfully at many major dams in the United States.

  9. Chemodiversity of Ladder-Frame Prymnesin Polyethers in Prymnesium parvum

    Rasmussen, Silas Anselm; Meier, Sebastian; Andersen, Nikolaj Gedsted;

    2016-01-01

    Blooms of the microalga Prymnesium parvum cause devastating fish kills worldwide, which are suspected to be caused by the supersized ladder-frame polyether toxins prymnesin-1 and -2. These toxins have, however, only been detected from P. parvum in rare cases since they were originally described two...

  10. Design and Implementation of Paired Pectoral Fins Locomotion of Labriform Fish Applied to a Fish Robot

    Patar Ebenezer Sitorus; Yul Yunazwin Nazaruddin; Edi Leksono; Agus Budiyono

    2009-01-01

    In present, there are increasing interests in the research on mechanical and control system of underwater vehicles. These ongoing research efforts are motivated by more pervasive applications of such vehicles including seabed oil and gas explorations, scientific deep ocean surveys, military purposes, ecological and water environmental studies, and also entertainments.However, the performance of underwater vehicles with screw type propellers is not prospective in terms of its efficiency and maneuverability. The main weaknesses of this kind of propellers are the production of vortices and sudden generation of thrust forces which make the control of the position and motion difficult.On the other hand, fishes and other aquatic animals are efficient swimmers, posses high maneuverability, are able to follow trajectories, can efficiently stabilize themselves in currents and surges, create less wakes than currently used underwater vehicle,and also have a noiseless propulsion. The fish's locomotion mechanism is mainly controlled by its caudal fin and paired pectoral fins. They are classified into Body and/or Caudal Fin (BCF) and Median and/or paired Pectoral Fins (MPF). The study of highly efficient swimming mechanisms of fish can inspire a better underwater vehicles thruster design and its mechanism.There are few studies on underwater vehicles or fish robots using paired pectoral fins as thruster. The work presented in this paper represents a contribution in this area covering study, design and implementation of locomotion mechanisms of paired pectoral fins in a fish robot. The performance and viability of the biomimetic method for underwater vehicles are highlighted through in-water experiment of a robotic fish.

  11. Novel Design Solutions for Fishing Reel Mechanisms

    LOVASZ Erwin-Christian; MODLER Karl-Heinz; NEUMANN Rudolf; GRUESCU Corina Mihaela; PERJU Dan; CIUPE Valentin; MANIU Inocentiu

    2015-01-01

    Currently, there are various reels on the market regarding the type of mechanism, which achieves the winding and unwinding of the line. The designers have the purpose of obtaining a linear transmission function, by means of a simple and small-sized mechanism. However, the present solutions are not satisfactory because of large deviations from linearity of the transmission function and complexity of mechanical schema. A novel solution for the reel spool mechanism is proposed. Its kinematic schema and synthesis method are described. The kinematic schema of the chosen mechanism is based on a noncircular gear in series with a scotch-yoke mechanism. The yoke is driven by a stud fixed on the driving noncircular gear. The drawbacks of other models regarding the effects occurring at the ends of the spool are eliminated through achieving an appropriate transmission function of the spool. The linear function approximation with curved end-arches appropriately computed to ensure mathematical continuity is very good. The experimental results on the mechanism model validate the theoretical approach. The developed mechanism solution is recorded under a reel spool mechanism patent.

  12. Traffic lights system in comparison instructions ladder program design ingenious application%比较指令在交通信号灯系统梯形图程序设计中的巧妙应用

    陈永方; 陈帮军; 刘朝中

    2015-01-01

    本篇文章简单介绍了西门子S7-200PLC系统在交通灯信号灯系统中的应用,重点介绍比较指令在交通信号灯系统梯形图程序设计当中的巧妙应用.%This article introduces the Siemens S7-200PLC system in the traffic light signal system, focusing on the comparison instruction in the ladder program traffic lights system designs clever applications.

  13. Evaluation through research of a three-track career ladder program for registered nurses.

    Korman, Carol; Eliades, Aris Beoglos

    2010-01-01

    A descriptive study design was employed to survey registered nurse participants in a career ladder program comprising of three tracks: clinical, education, and management. Findings indicate that participation allows nurses of varying education preparation and roles to demonstrate professional development. Implications for staff development include efficacy of the online survey technique, provision of a reliable tool to evaluate a career ladder, and evaluation of a career ladder that includes the staff development educator.

  14. Bending continuous structures with SMAs: a novel robotic fish design.

    Rossi, C; Colorado, J; Coral, W; Barrientos, A

    2011-12-01

    In this paper, we describe our research on bio-inspired locomotion systems using deformable structures and smart materials, concretely shape memory alloys (SMAs). These types of materials allow us to explore the possibility of building motor-less and gear-less robots. A swimming underwater fish-like robot has been developed whose movements are generated using SMAs. These actuators are suitable for bending the continuous backbone of the fish, which in turn causes a change in the curvature of the body. This type of structural arrangement is inspired by fish red muscles, which are mainly recruited during steady swimming for the bending of a flexible but nearly incompressible structure such as the fishbone. This paper reviews the design process of these bio-inspired structures, from the motivations and physiological inspiration to the mechatronics design, control and simulations, leading to actual experimental trials and results. The focus of this work is to present the mechanisms by which standard swimming patterns can be reproduced with the proposed design. Moreover, the performance of the SMA-based actuators' control in terms of actuation speed and position accuracy is also addressed.

  15. Variations of the Sliding Ladder Problem

    Kapranidis, Stelios; Koo, Reginald

    2008-01-01

    This article takes another look at the sliding ladder problem that students meet in the study of related rates in calculus. Physically realistic situations with both constrained and understrained ladders are explored.

  16. A Review and Modern Approach to LC Ladder Synthesis

    Alexander J. Casson

    2011-01-01

    Full Text Available Ultra low power circuits require robust and reliable operation despite the unavoidable use of low currents and the weak inversion transistor operation region. For analogue domain filtering doubly terminated LC ladder based filter topologies are thus highly desirable as they have very low sensitivities to component values: non-exact component values have a minimal effect on the realised transfer function. However, not all transfer functions are suitable for implementation via a LC ladder prototype, and even when the transfer function is suitable the synthesis procedure is not trivial. The modern circuit designer can thus benefit from an updated treatment of this synthesis procedure. This paper presents a methodology for the design of doubly terminated LC ladder structures making use of the symbolic maths engines in programs such as MATLAB and MAPLE. The methodology is explained through the detailed synthesis of an example 7th order bandpass filter transfer function for use in electroencephalogram (EEG analysis.

  17. Oscillator Based on Lumped Double Ladder Circuit with Band Edge Degeneracy

    Oshmarin, Dmitry; Othman, Mohamed A K; Sloan, Jeff; Radfar, Mohammad; Green, Michael M; Capolino, Filippo

    2016-01-01

    An oscillator design based on a periodic, double ladder resonant circuit is proposed. The circuit exhibits a degenerate band edge (DBE) in the dispersion diagram of its phase-frequency eigenstates, and possesses unique resonance features associated with a high Q-factor resonance, compared to a single ladder or a conventional LC tank circuit. This oscillator is shown to have an oscillation threshold that is half that of a single LC ladder circuit having the same total quality factor, and thus is more robust than an LC oscillator in the presence of losses. It is also shown that the output and amplitude of the double-ladder oscillator is much less sensitive to the output loading compared to single-ladder oscillators. We show the analysis and design of such oscillators that potentially lead to enhancing the efficiency of RF components and sources.

  18. Discrete breathers in Josephson ladders

    Trias, E.; Mazo, J.J.; Brinkman, A.; Orlando, T.P.

    2001-01-01

    We present a study of nonlinear localized excitations called discrete breathers in a superconducting array. These localized solutions were recently observed in Josephson-junction ladder arrays by two different experimental groups [Phys. Rev. Lett. 84 (2000) 741; Phys. Rev. Lett. 84 (2000) 745; Phys.

  19. Genus Distributions of Moebius Ladders

    李德明

    2005-01-01

    The genus distribution of a graph is a polynomial whose coefficients are the partition of the number of embeddings with respect to the genera. In this paper,the genus distribution of Moebius ladders is provided which is an infinite class of 3-connected simple graphs.

  20. Assessments to determine the effect of current and alternate ladder operations on brood stock collection and behavior of hatchery fall Chinook Salmon at Little White Salmon National Fish Hatchery during 2004-05

    US Fish and Wildlife Service, Department of the Interior — Production of upriver bright fall Chinook salmon at Little White Salmon National Fish Hatchery was introduced as part of the John Day Dam mitigation program in the...

  1. Fish-inspired robots: design, sensing, actuation, and autonomy--a review of research.

    Raj, Aditi; Thakur, Atul

    2016-04-13

    Underwater robot designs inspired by the behavior, physiology, and anatomy of fishes can provide enhanced maneuverability, stealth, and energy efficiency. Over the last two decades, robotics researchers have developed and reported a large variety of fish-inspired robot designs. The purpose of this review is to report different types of fish-inspired robot designs based upon their intended locomotion patterns. We present a detailed comparison of various design features like sensing, actuation, autonomy, waterproofing, and morphological structure of fish-inspired robots reported in the past decade. We believe that by studying the existing robots, future designers will be able to create new designs by adopting features from the successful robots. The review also summarizes the open research issues that need to be taken up for the further advancement of the field and also for the deployment of fish-inspired robots in practice.

  2. Chemodiversity of Ladder-Frame Prymnesin Polyethers in Prymnesium parvum

    Rasmussen, Silas Anselm; Meier, Sebastian; Andersen, Nikolaj Gedsted;

    2016-01-01

    Blooms of the microalga Prymnesium parvum cause devastating fish kills worldwide, which are suspected to be caused by the supersized ladder-frame polyether toxins prymnesin-1 and -2. These toxins have, however, only been detected from P. parvum in rare cases since they were originally described two......-HRMS) of 10 strains of P. parvum collected worldwide showed that only one strain produced the original prymnesin-1 and -2, whereas four strains produced the novel B-type prymnesin. In total 13 further prymnesin analogues differing in their core backbone and chlorination and glycosylation patterns could...

  3. Six-degree-of-freedom Sensor Fish design - Governing equations and motion modeling

    Zeng, D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Richmond, M. C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Simmons, C. S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Carlson, T. J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2004-07-01

    The Sensor Fish device is being used at Northwest hydropower projects to better understand the conditions fish experience during passage through hydro turbines and other dam bypass alternatives. Since its initial development in 1997, the Sensor Fish has undergone numerous design changes to improve its function and extend the range of its use. The most recent Sensor Fish design, the three degree of freedom (3DOF) device, has been used successfully to characterize the environment fish experience when passing through turbines, in spill, or in engineered fish bypass facilities at dams. Pacific Northwest National Laboratory (PNNL) is in the process of redesigning the current 3DOF Sensor Fish device package to improve its field performance. Rate gyros will be added to the new six degree of freedom (6DOF) device so that it will be possible to observe the six linear and angular accelerations of the Sensor Fish as it passes the dam. Before the 6DOF Sensor Fish device can be developed and deployed, governing equations of motion must be developed in order to understand the design implications of instrument selection and placement within the body of the device. The report describes a fairly general formulation for the coordinate systems, equations of motion, force and moment relationships necessary to simulate the 6DOF movement of an underwater body.

  4. A marsupial robotic fish team: Design, motion and cooperation

    2010-01-01

    A bio-inspired marsupial robotic fish system composed of heterogeneous robotic fish is proposed in this paper. A miniature robotic fish, as the daughter robotic fish, can adapt to some narrow space, while the mother robotic fish, with a cabin to transport the daughter, possesses a powerful movement ability to improve the mobility and endurance of the team. The structures for mimicking bio-motion and the method for fishlike-motion are presented. A typical task of daughter-mother following is given to show the cooperation of the team. A motion model of free swimming is built based on the Lagrangian function, and the coupled dynamic and kinematic functions are calculated based on the relation between the generalized force and fluid force. Then, a neural network is trained through the data generated from this model to get a predictive yaw controller, which can control the orientation by a different offset of each link. The daughter robotic fish adopts a dynamic light source tracking approach to follow the mother, and a heterogeneous communication-based finite state machine is presented for task modeling. Experiments are carried out to verify the system.

  5. INVESTIGATING PECTORAL SHAPES AND LOCOMOTIVE STRATEGIES FOR CONCEPTUAL DESIGNING BIO-INSPIRED ROBOTIC FISH

    A. I. MAINONG

    2017-01-01

    Full Text Available This paper describes the performance analysis of a conceptual bio-inspired robotic fish design, which is based on the morphology similar to the boxfish (Ostracion melagris. The robotic fish prototype is driven by three micro servos; two on the pectoral fins, and one on the caudal fin. Two electronic rapid prototyping boards were employed; one for the movement of robotic fish, and one for the force sensors measurements. The robotic fish were built using fused deposition modeling (FDM, more popularly known as the 3D printing method. Several designs of pectoral fins (rectangular, triangular and quarter-ellipse with unchanging the value of aspect ratio (AR employed to measure the performance of the prototype robotic fish in terms of hydrodynamics, thrust and maneuvering characteristics. The analysis of the unmanned robotic system performance is made experimentally and the results show that the proposed bioinspired robotic prototype opens up the possibility of design optimization research for future work.

  6. Laddering em pesquisa de marketing

    Tânia Modesto Veludo-de-Oliveira

    Full Text Available O artigo discute a técnica de pesquisa laddering em marketing, considerando a proposta de renovação de conhecimentos sobre metodologia na área. Para isso investiga diversos estudos, artigos e pesquisas que tratam do assunto em nível nacional e internacional. O conceito de cadeias meios-fins é abordado pela estrutura teórica que fundamenta a técnica, ligando atributos, conseqüências percebidas do consumo e valores pessoais relativos a um produto. O artigo segue com a explicação dos procedimentos de campo, como a entrevista e a análise dos dados. A laddering é um instrumento de pesquisa qualitativa bastante útil e poderoso, mas ainda pouco utilizado tanto por acadêmicos como por profissionais de mercado, no Brasil, provavelmente por desconhecimento e pouca divulgação. Cabe, portanto, uma maior disseminação de seu uso.

  7. Fishing

    姜群山

    2002-01-01

    @@ Last Saturday my cousin (表兄) came to my home. We were very happy to see each other. We decided that the next day we went to fish. We got up very early that day. When we left home,the moon could still be seen in the sky.

  8. Final turbine and test facility design report Alden/NREC fish friendly turbine

    Cook, Thomas C. [Alden Research Lab., Holden, MA (United States); Cain, Stuart A. [Alden Research Lab., Holden, MA (United States); Fetfatsidis, Paul [Alden Research Lab., Holden, MA (United States); Hecker, George E. [Alden Research Lab., Holden, MA (United States); Stacy, Philip S. [Alden Research Lab., Holden, MA (United States)

    2000-09-01

    The final report provides an overview of the Alden/NREC Fish Friendly turbine design phase, turbine test plan, preliminary test results, costs, schedule, and a hypothetical application at a real world project.

  9. Fish Farm Challenge Provides STEM Design Experiences for Youth

    Horton , Robert L.; House, Patty L.

    2015-01-01

    In 2014, Monsanto Corporation partnered with National 4-H Council to help inspire and develop professional skills among young agriculturalists. The Ohio State University created Fish Farm Challenge, which engaged more than 8,000 youth across eight states. Youth were taught about worldwide food insecurity and the importance of aquaculture. They…

  10. White Porcelain Jar with Double-Fish Design

    1999-01-01

    Fish were a frequently used theme forartwork in ancient times, as they arebelieved to represent ’surplus in thecoming years.’ This white porcelain jarwas a product of the Xing Kiln, HebeiProvince in the late Tang Dynasty and wasunearthed in Jingjing County. Xing Kiln is located in the areas ofNeiqiu and Lincheng and got the name

  11. Six-Degree-of-Freedom Sensor Fish Design: Governing Equations and Motion Modeling

    Deng, Zhiqun; Richmond, Marshall C.; Simmons, Carver S.; Carlson, Thomas J.

    2004-08-19

    The Sensor Fish device is being used at Northwest hydropower projects to better understand the conditions fish experience during passage through hydroturbines and other dam bypass alternatives. Since its initial development in 1997, the Sensor Fish has undergone numerous design changes to improve its function and extend the range of its use. The most recent Sensor Fish design, the three degree of freedom (3DOF) device, has been used successfully to characterize the environment fish experience when passing through turbines, in spill, or in engineered fish bypass facilities at dams. Pacific Northwest National Laboratory (PNNL) is in the process of redesigning the current 3DOF Sensor Fish device package to improve its field performance. Rate gyros will be added to the new six degree of freedom (6DOF) device so that it will be possible to observe the six linear and angular accelerations of the Sensor Fish as it passes the dam. Before the 6DOF Sensor Fish device can be developed and deployed, governing equations of motion must be developed in order to understand the design implications of instrument selection and placement within the body of the device. In this report, we describe a fairly general formulation for the coordinate systems, equations of motion, force and moment relationships necessary to simulate the 6DOF movement of an underwater body. Some simplifications are made by considering the Sensor Fish device to be a rigid, axisymmetric body. The equations of motion are written in the body-fixed frame of reference. Transformations between the body-fixed and interial reference frames are performed using a formulation based on quaternions. Force and moment relationships specific to the Sensor Fish body are currently not available. However, examples of the trajectory simulations using the 6DOF equations are presented using existing low and high-Reynolds number force and moment correlations. Animation files for the test cases are provided in an attached CD. The next

  12. The transient ladder synchronization of chaotic systems

    Chen, H.-K. [Department of Industrial Engineering and Management, Hsiuping Institute of Technology, No. 11, Gungye Rd., Dali City, Taichung, Taiwan (China)]. E-mail: kanechen@giga.net.tw; Sheu, L.-J. [Department of Mechanical Engineering, Chung Hua University, Hsinchu, Taiwan (China)]. E-mail: ljsheu@chu.edu.tw

    2006-07-03

    A new type for chaotically synchronizing systems, transient ladder chaos synchronization, is proposed in this Letter. For some physical systems, chaotic synchronization is possible in only some of the variables. It is shown that, for the non-synchronizing variable, synchronization up to a constant difference for t{sub 1}=ladder chaos synchronization and anti-synchronization are illustrated by using two identical chaotic Froude pendulums. Numerical simulations are shown for demonstration.

  13. Nuclear Escalation Ladders in South Asia

    2011-04-01

    Ibid., pp. 211-212. 23 Fig. 3. Indian Escalation Ladder - Facing China in the Himalayas Response or Initiative Rung Order Thresholds and Rungs Peace...potential land-warfare ladders in the Himalayas . A. Territorial Boundaries India and Pakistan face each other across a common international... Himalayas from Ladakh in Kashmir south and east for 2,100 miles, interrupted by Nepal and Bhutan, which have their own northern borders with China of 768 and

  14. Clinical career ladders: Hamot Medical Center.

    Meyer, J D; Chrymko, M M; Kelly, W N

    1989-11-01

    The clinical career ladder program for pharmacists at Hamot Medical Center (HMC), a 500-bed not-for-profit community teaching hospital, is described. Between 1980 and 1989 a career ladder at HMC evolved from an idea to an established program with parallel administrative, business, and clinical tracks. The development of the career ladder mirrored the growth of clinical programs and the diversification of pharmaceutical services. A formal plan for a clinical ladder was developed when the first satellite pharmacy opened in 1984. An entry-level pharmacist at HMC starts with a six-month period during which he or she learns the drug distribution system and prepares for several certification tests. The employee is then promoted to staff pharmacist. Staff pharmacists are promoted to clinical pharmacist II (CP II) upon meeting requirements for competence in a broad range of clinical skills and knowledge. Candidates for the position of clinical pharmacist specialist (CP I) must have either a minimum of three years of experience as a CP II or a Pharm.D. degree and have established an area of clinical expertise. A CP I can progress to assistant and associate director positions as vacancies occur. The clinical ladder has enhanced job satisfaction and encouraged the development of clinical practitioners who provide improved care. Problems have included time constraints, competition for positions, and management of incentives. A parallel career ladder program with a clinical track has enhanced the growth of pharmacy practice at HMC and improved the quality of pharmaceutical care.

  15. FishPath: computer application for design of vertical slot fishways

    María Bermúdez

    2015-07-01

    Full Text Available Vertical slot fishways are hydraulic structures designed to allow fish migration through obstacles in rivers. The appropriate design of these devices depends on an interplay between hydraulic and biological variables, since the hydrodynamic properties of the fishway must meet the requirements of the fish species for which it is intended. This paper presents a computer application to analyze the efficiency of a fishway model according to biological criteria. The proposed model applies restrictions relative to the swimming capacity of fish, their depth requirements and their needs regarding turbulent energy dissipation. It allows the objective comparison of designs and the determination of which is to be more efficient. It is expected that the application can provide guidance to the technicians involved in fishway design regarding the systematic application of hydrobiological criteria, which also incorporate the latest research findings in this field.

  16. A towed body designed for side-scanning hydroacoustic surveying of fish stocks in shallow waters

    Mous, P.J.; Kemper, J.; Schelvis, A.

    1999-01-01

    An aluminum towed body was designed for use in hydroacoustic surveying of fish stocks in shallow (2–10 m depth) inland waters. The design allows applications in deep (>10 m) water bodies as well. Test results showed that the towed body was a stable platform for the hydroacoustic transducer. The towe

  17. Locomotion Generation and Motion Library Design for an Anguilliform Robotic Fish

    Xuelei Niu; Jianxin Xu; Qinyuan Ren; Qingguo Wang

    2013-01-01

    In this paper,modeling,locomotion generation,motion library design and path planning for a real prototype of an Anguilliform robotic fish are presented.The robotic fish consists of four links and three joints,and the driving forces are the torques applied to the joints.Considering kinematic constraints and hydrodynamic forces,Lagrangian formulation is used to obtain the dynamic model of the fish.Using this model,three major locomotion patterns of Anguilliform fish,including forward locomotion,backward locomotion and turning locomotion are investigated.It is found that the fish exhibits different locomotion pattems by giving different reference joint angles,such as adding reversed phase difference,or adding deflections to the original reference angles.The results are validated by both simulations and experiments.Furthermore,the relations among the speed of the fish,angular frequency,undulation amplitude,phase difference,as well as the relationship between the turning radius and deflection angle are investigated.These relations provide an elaborated motion library that can be used for motion planning of the robotic fish.

  18. Evolutionary multiobjective design of a flexible caudal fin for robotic fish.

    Clark, Anthony J; Tan, Xiaobo; McKinley, Philip K

    2015-11-25

    Robotic fish accomplish swimming by deforming their bodies or other fin-like appendages. As an emerging class of embedded computing system, robotic fish are anticipated to play an important role in environmental monitoring, inspection of underwater structures, tracking of hazardous wastes and oil spills, and the study of live fish behaviors. While integration of flexible materials (into the fins and/or body) holds the promise of improved swimming performance (in terms of both speed and maneuverability) for these robots, such components also introduce significant design challenges due to the complex material mechanics and hydrodynamic interactions. The problem is further exacerbated by the need for the robots to meet multiple objectives (e.g., both speed and energy efficiency). In this paper, we propose an evolutionary multiobjective optimization approach to the design and control of a robotic fish with a flexible caudal fin. Specifically, we use the NSGA-II algorithm to investigate morphological and control parameter values that optimize swimming speed and power usage. Several evolved fin designs are validated experimentally with a small robotic fish, where fins of different stiffness values and sizes are printed with a multi-material 3D printer. Experimental results confirm the effectiveness of the proposed design approach in balancing the two competing objectives.

  19. Transport properties of a ladder with two random dimer chains

    Hu Donng-Sheng; Zhu Chen-Ping; Zhang Yong-Mei

    2011-01-01

    We investigate the transport properties of a ladder with two random dimer (RD) chains. It is found that there are two extended states in the ladder with identical RD chains and a critical state regarded as an extended state in the ladder with pairing RD chains. Such a critical state is caused by the chiral symmetry. The ladder with identical RD chains can be decoupled into two isolated RD chains and the ladder with pairing RD chains can not. The analytic expressions of the extended states are presented for the ladder with identical RD chains.

  20. Design and Implementation of SoftPLC Ladder Diagram Programming Tool Based on MiniGUI%基于MiniGUI的梯形图编程工具的设计与实现

    姚家庆; 陶耀东; 郑一麟

    2013-01-01

    针对数控系统可编程逻辑控制器(PLC),使用MiniGUI实现一个梯形图编程工具.首先指出MiniGUI占用资源低、移植性好等优点.随后提出图元的数据结构、手动绘制图元的方法,在此基础之上给出梯形图的数据结构以及如何刷新梯形图.此外,编程系统使用“正向深度扫描算法”来实现梯图向IL程序的转换并且在转换之前还对梯图进行一些语法正确性的检查.最后给出一个梯形图转换的实例,验证了编辑工具的实用性.%In view of the Programmable Logic Controller ( PLC ) in numerical controller system, MiniGUI is used to realize a ladder diagram programming tool. Firstly, some advantages such as low occupancy of system resources, good portability are pointed out. Then the data structure and the method of drawing graphical objects are devised. On the the basis of graphical object, the data structure and the method of refreshing ladder diagram are proposed. In addition, an algorithm named " straight and deep traversal algorithm" is used to convert ladder diagram into IL program and syntactic correctness check is also needed befor the conversion. Finally, this paper gives a ladder diagram conversion instance which validates the utility of this tool.

  1. Dipoles on a Two-leg Ladder

    Gammelmark, Søren; Zinner, Nikolaj Thomas

    2013-01-01

    We study polar molecules with long-range dipole-dipole interactions confined to move on a two-leg ladder for different orientations of the molecular dipole moments with respect to the ladder. Matrix product states are employed to calculate the many-body ground state of the system as function...... of lattice filling fractions, perpendicular hopping between the legs, and dipole interaction strength. We show that the system exhibits zig-zag ordering when the dipolar interactions are predominantly repulsive. As a function of dipole moment orientation with respect to the ladder, we find...... that there is a critical angle at which ordering disappears. This angle is slightly larger than the angle at which the dipoles are non-interacting along a single leg. This behavior should be observable using current experimental techniques....

  2. First Catch Your Fish: Designing a “Low Energy Fish” Label

    Andy Grinnall

    2015-05-01

    Full Text Available This paper explores the application of information design principles to label design for fish packaging, identifying energy implications for the product. This stage of the project has consisted of: A review and distillation of the relevant literature on information and label design; environmental and labelling standards; and literature on consumer reaction to the design and information content of the label. Considering the design of a label requires the analysis and integration of a variety of factors while attempting to satisfy the demands of consumers and retailers.

  3. Design, Implementation and Control of a Fish Robot with Undulating Fins

    Mohsen Siahmansouri

    2011-11-01

    Full Text Available Biomimetic robots can potentially perform better than conventional robots in underwater vehicle designing. This paper describes the design of the propulsion system and depth control of a robotic fish. In this study, inspired by knife fish, we have designed and implemented an undulating fin to produce propulsive force. This undulating fin is a segmental anal fin that produces sinusoidal wave to propel the robot. The relationship between the individual fin segment and phase angles with the overall fin trajectory has also been discussed. This propulsive force can be adjusted and directed for fish robot manoeuvre by a mechanical system with two servomotors. These servomotors regulate the direction and depth of swimming. A wireless remote control system is designed to adjust the servomotors which enables us to control revolution, speed and phase differences of neighbor servomotors of fins. Finally, Field trials are conducted in an outdoor pool to demonstrate the relationship between robotic fish speed and fin parameters like phase difference, the number of phase and undulatory amplitude.

  4. Hydraulic design of a tilting weir allowing for periodic fish migration

    Hoitink, A.J.F.; Dommerholt, A.; Gerven, van L.P.A.

    2008-01-01

    The hydraulic design of a tilting weir is presented, which allows for periodic exchange of potadromous fish between freshwater ecosystems. The application domain includes inland waters that need to be isolated hydraulically, preserving the existing ecological connection with the surrounding areas as

  5. DNA Ladder的制备%Preparation of DNA Ladder

    王俐; 董卫华; 张俊河; 王天云

    2011-01-01

    definition and could be equal with that of commercial products. It could be used in the molecular biology experiments.OBJECTIVE: To prepare DNA molecular weight standard control.METHODS: A specific plasmid pUC-DNA for PCR amplification was constructed, according to the sequence of pUC-DNA.Primers were designed to amplify 100-1 000 bp DNA fragments followed by primer5.0. 100-1 000 b p series DNA fragments were amplified and electrophoresised in 2% agarose gels. After identification by PCR recovery products and DNA sequencing,the DNA sequences were analyzed according to the pUC-DNA and the homology analysis was compared analyzed by blast. The PCR products were extracted by phenol/chloroform, precipitated with ethanol and mixed them proportionally.RESULTS AND CONCLUSION: 100-1 000 bp DNA fragments were successfully amplified by PCR technique, and the size of the bands were the same as the expected. The purified bands were clear. The 100-1000 bp DNA ladder was prepared in our laboratory. The method is convenient and the size of the prepared DNA ladder is standard, it could be used in the molecular biology experiments.

  6. Vibrational ladder climbing in NO using ultrashort IR laser pulses

    Maas, D. J.; Duncan, D. I.; van der Meer, A. F. G.; van der Zande, W. J.; Noordam, L. D.; Lambropoulos, P.; Walther, H.

    1997-01-01

    Chirped excitation of an electronic ladder system has shown complete transfer of the population to the top-level of the ladder system. Similar excitation of vibrational ladders in molecules may provide a tool for state-selective chemistry. Experimental results on the climbing of the anharmonic vibra

  7. 46 CFR 197.320 - Diving ladder and stage.

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Diving ladder and stage. 197.320 Section 197.320... STANDARDS GENERAL PROVISIONS Commercial Diving Operations Equipment § 197.320 Diving ladder and stage. (a) Each diving ladder must— (1) Be capable of supporting the weight of at least two divers; (2) Extend...

  8. The Static Ladder Problem with Two Sources of Friction

    Bennett, Jonathan; Mauney, Alex

    2011-01-01

    The problem of a ladder leaning against a wall in static equilibrium is a classic example encountered in introductory mechanics texts. Most discussions of this problem assume that the static frictional force between the ladder and wall can be ignored. A few authors consider the case where the static friction coefficients between ladder/wall…

  9. 5 CFR 335.104 - Eligibility for career ladder promotion.

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Eligibility for career ladder promotion... REGULATIONS PROMOTION AND INTERNAL PLACEMENT General Provisions § 335.104 Eligibility for career ladder promotion. No employee shall receive a career ladder promotion unless his or her current rating of...

  10. Analysis of Environmental Issues Related to Small-Scale Hydroelectric Development II: Design Consideration for Passing Fish Upstream Around Dams

    Hildebrandt, S. G. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bell, M. C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Anderson, J. J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Richey, E. P. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Parkhurst, Z. E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    1980-08-01

    The purpose of this report is to provide general information for use by potential developers of small scale hydroelectric projects that will include facilities to pass migrating fish upstream around dams. The document is not intended to be a textbook on design of fish passage facilities, but rather to be a general guide to some factors that are important when designing such facilities.

  11. Application of biological design criteria and computational fluid dynamics to investigate fish survival in Kaplan turbines

    Garrison, Laura A. [Voith Siemens Hydro Power Generation, Inc., York, PA (United States); Fisher, Jr., Richard K. [Voith Siemens Hydro Power Generation, Inc., York, PA (United States); Sale, Michael J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Cada, Glenn [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2002-07-01

    One of the contributing factors to fish injury in a turbine environment is shear stress. This paper presents the use of computational fluid dynamics (CFD) to display and quantify areas of elevated shear stress in the Wanapum Kaplan turbine operating at four different flow conditions over its operating range. CFD observations will be compared to field test observations at the same four flow conditions. Methods developed here could be used to facilitate the design of turbines and related water passages with lower risks of fish injury.

  12. Effect of spray nozzle design on fish oil-whey protein microcapsule properties.

    Legako, Jerrad; Dunford, Nurhan Turgut

    2010-08-01

    Microencapsulation improves oxidative stability and shelf life of fish oil. Spray and freeze drying are widely used to produce microcapsules. Newer spray-nozzles utilize multiple fluid channels allowing for mixing of wall and core materials at the point of atomization. Sonic energy has also been employed as a means of atomization. The objective of this study was to examine the effect of nozzle type and design on fish oil encapsulation efficiency and microcapsule properties. A total of 3 nozzle types, a pressure nozzle with 1 liquid channel, a pressure nozzle with 2 liquid channels, and a sonic atomizer with 2 liquid channels were examined for their suitability to encapsulate fish oil in whey protein isolate. Physical and chemical properties of freeze dried microcapsules were compared to those of microcapsules produced by spray drying. The 2-fluid pressure and ultrasonic nozzles had the highest (91.6%) and the lowest microencapsulation efficiencies (76%), respectively. There was no significant difference in bulk density of microcapsules produced by ultrasonic and 3-fluid pressure nozzles. The ultrasonic nozzle showed a significantly narrower particle size distribution than the other nozzles. This study demonstrated that new nozzle designs that eliminate emulsion preparation prior to spray drying can be beneficial for microencapsulation applications. However, there is still a need for research to improve microencapsulation efficiency of multiple channel spray nozzles. Practical Application: Since this research evaluates new spray nozzle designs for oil microencapsulation, the information presented in this article could be an interest to fish oil producers and food industry.

  13. Calculated Investigation of Gravitational Sagging of ITS Outer Layer Model Ladder for ALICE and Optimization of Parameters of Ladder

    Gloukhov, N P; CERN. Geneva

    1996-01-01

    The report presents results of stiffness' calculations of the about 1.1 m length lightweight model ladder and some of its modifications for Inner Tracking System Abstract: for ALICE. As a result, dependences of the ladder's stiffness and mass Abstract: Abstract: characteristics on its geometrical parameters are investigated and an optimum structure of the ladder Abstract: (carbon fibre space frame) is determined.

  14. Contribution of experimental fluid mechanics to the design of vertical slot fish passes

    Wang R.W.

    2010-02-01

    Full Text Available This paper presents the main results of an experimental study of mean and turbulent characteristics of flow in a scale model of a vertical slot fish pass with varying width and slope (from 5% to 15%. Experimental hydraulic modelling was combined with the study of fish behaviour in the model. The discharge coefficient, which significantly affects the design of such facilities, varied from 0.67 to 0.89 and was strongly influenced by the slope. Two distinct flow patterns were observed, depending on the slope and the fish pass width. The point of transition between the two states was determined. Low velocity areas are likely resting zones for fish and particular attention was paid to evaluating these areas. Slope was found to affect both the volume of the low velocity zone, and the value of turbulent kinetic energy in these areas. The statistical characteristics of turbulent kinetic energy in the pools were linked primarily to the maximum velocity in the jet. An analysis of the behaviour of juvenile brown trout (Salmo trutta in the scale model clearly showed that the fish avoided the areas of high velocities in the jet, except at the slot itself where they took advantage of the jet’s non-stationary character. Low-velocity areas were not frequented uniformly by fish, which stayed most frequently in the zone located just downstream from the slot and behind the small side baffle. It is suggested that future studies might investigate lower pool-length to slot-width ratios, which might make it possible to increase the slope significantly and should also examine ways of improving hydraulic conditions for fish by carefully distributing obstacles in pools.

  15. A comparison of two sampling designs for fish assemblage assessment in a large river

    Kiraly, Ian A.; Coghlan Jr., Stephen M.; Zydlewski, Joseph; Hayes, Daniel

    2014-01-01

    We compared the efficiency of stratified random and fixed-station sampling designs to characterize fish assemblages in anticipation of dam removal on the Penobscot River, the largest river in Maine. We used boat electrofishing methods in both sampling designs. Multiple 500-m transects were selected randomly and electrofished in each of nine strata within the stratified random sampling design. Within the fixed-station design, up to 11 transects (1,000 m) were electrofished, all of which had been sampled previously. In total, 88 km of shoreline were electrofished during summer and fall in 2010 and 2011, and 45,874 individuals of 34 fish species were captured. Species-accumulation and dissimilarity curve analyses indicated that all sampling effort, other than fall 2011 under the fixed-station design, provided repeatable estimates of total species richness and proportional abundances. Overall, our sampling designs were similar in precision and efficiency for sampling fish assemblages. The fixed-station design was negatively biased for estimating the abundance of species such as Common Shiner Luxilus cornutus and Fallfish Semotilus corporalis and was positively biased for estimating biomass for species such as White Sucker Catostomus commersonii and Atlantic Salmon Salmo salar. However, we found no significant differences between the designs for proportional catch and biomass per unit effort, except in fall 2011. The difference observed in fall 2011 was due to limitations on the number and location of fixed sites that could be sampled, rather than an inherent bias within the design. Given the results from sampling in the Penobscot River, application of the stratified random design is preferable to the fixed-station design due to less potential for bias caused by varying sampling effort, such as what occurred in the fall 2011 fixed-station sample or due to purposeful site selection.

  16. Optimizing of the functionality of fish passes; Optimierung der Auffindbarkeit von Fischaufstiegsanlagen

    Sobirey, Axel [WAGU GmbH Kassel (Germany)

    2011-07-01

    An important criterion of the correct operation of fish passes is their ease of localize for fishes and benthos willing to migrate upstream. If in practice an optimal solution can not be realized because of local restrictions, some aids can improve the functionality of fish ladders, such as a supplied tube, a fish attracting pump or a useful positioned fish deflector. (orig.)

  17. Multiinstanton ladders in baryon number violating processes

    Lazarides, G

    1995-01-01

    We estimate the contribution of a class of multiinstanton ladder graphs to baryon and lepton number violating processes in the standard model. We find that this contribution is negligible and does not alter the high energy behavior of the leading semiclassical approximation.

  18. The Entrepreneurial Ladder and its Determinants

    Zwan, van der Peter; Thurik, Roy; Grilo, Isabel

    2006-01-01

    We test a new model where the entrepreneurial decision is described as a process of successive engagement levels, i.e., as an entrepreneurial ladder. Five levels are distinguished using nearly 12,000 observations from the 2004 Flash Eurobarometer survey on Entrepreneurship covering the 25 European U

  19. Development of Single- and Double-sided Ladders for the ILD Vertex Detectors

    Baudot, Jerome; Chon-Sen, Nathalie; Dulinski, Wojciech; Hegner, Franziska; Gelin-Galibel, Marie; Gauld, Rhorry; Goffe, Mathieu; Goldstein, Joel; Gregor, Ingrid; Hu-Guo, Christine; Koetz, Ulrich; Nomerotski, Andrei; Winter, Marc

    2012-01-01

    We discuss two projects exploring the integration of thin CMOS pixel sensors in order to prototype ladders matching the geometry needed for the ILD vertex detector. The PLUME project has designed and fabricated full-size and fully functional double- sided layers which currently reach 0.6 % X0 and aim for 0.3 % X0 in mid-2012. Another approach, SERNWIETE, consists in wrapping the sensors in a polyimide-based micro-cable to obtain a supportless single-sided ladder with a material budget around 0.15 % X0. First promising samples have been produced and the full-size prototype is expected in spring 2012.

  20. LADDER SUPERSTRUCTURE-DIRECTED SYNTHESIS OF A WELL-DEFINED m-PHENELENEDIIMINO-BRIDGED LADDER POLYMETHYLSILOXANE

    Yin-sheng Lv; Zhong-jie Ren; You-zhi Wan; Ping Xie; Rong-ben Zhang

    2009-01-01

    A well-defined m-phenylenediimino-bridged ladder polymethylsiloxane (LP) was first synthesized through a well-defined ladder superstructure (LS) acting as synthetic template, which was self-assembled by concerted interaction of hydrogen bonding and aromatic π-π stacking of the monomer (M), N,N'-bis(phenyldichlorosilyl)-m-phenylenediamine. Some key characterization data of LP and, in particular, the extremely vulnerable LS with very unstable Si--Cl and Si-N groups were given. The molecular weights (Mn) of LS and LP are 5010 and 10480, corresponding to about 15 and 46 monomer units, respectively. To monitor the real in situ status of LS in solution the XRD measurements of special freeze-drying samples were performed, demonstrating two characteristic peaks of ladder structure. Most importantly, both LP and LS display exceedingly sharp resonance absorption peaks with a half peak width (△1/2) as small as < 0.3 of MeSi(NH)O2/2 moieties in 29Si-NMR spectra. It is well-known that the higher the regularity of the ladder polysiloxane, the narrower the resonance peak of the siloxane moiety on the ladder backbone, and the smaller the half peak width △1/2. Therefore, the very small values of △1/2 for both LS and LP confirm that both LS and LP possess well-defined ladder structures.

  1. Walla Walla River Fish Passage Operations Program, 2004-2005 Annual Report.

    Bronson, James P. (Confederated Tribes of the Umatilla Indian Reservation, Department of Natural Resources, Pendleton, OR); Duke, Bill B. (Oregon Department of Fish and Wildlife, Pendleton, OR)

    2006-02-01

    In the late 1990s, the Confederated Tribes of the Umatilla Indian Reservation, Oregon Department of Fish and Wildlife, and Washington Department of Fish and Wildlife, along with many other agencies, began implementing fisheries restoration activities in the Walla Walla Basin. An integral part of these efforts is to alleviate the inadequate fish migration conditions in the basin. The migration concerns are being addressed by removing diversion structures, constructing fish passage facilities, implementing minimum instream flow requirements, and providing trap and haul efforts when needed. The objective of the Walla Walla River Fish Passage Operations Project is to increase the survival of migrating adult and juvenile salmonids in the Walla Walla River basin. The project is responsible for coordinating operation and maintenance of ladders, screen sites, bypasses, trap facilities, and transportation equipment. In addition, the project provides technical input on passage criteria and passage and trapping facility design and operation. Operation of the various passage facilities and passage criteria guidelines are outlined in an annual operations plan that the project develops. During the 2004-2005 project year, there were 590 adult summer steelhead, 31 summer steelhead kelts (Oncorhynchus mykiss), 70 adult bull trout (Salvelinus confluentus); 80 adult and 1 jack spring Chinook (O. tshawytscha) enumerated at the Nursery Bridge Dam fishway video counting window between December 13, 2004, and June 16, 2005. Summer steelhead and spring chinook were observed moving upstream while bull trout were observed moving both upstream and downstream of the facility. In addition, the old ladder trap was operated by ODFW in order to enumerate fish passage. Of the total, 143 adult summer steelhead and 15 summer steelhead kelts were enumerated at the west ladder at Nursery Bridge Dam during the video efforts between February 4 and May 23, 2005. Operation of the Little Walla Walla River

  2. Design, synthesis, and characterization of ladder-type molecules and polymers. Air-stable, solution-processable n-channel and ambipolar semiconductors for thin-film transistors via experiment and theory.

    Usta, Hakan; Risko, Chad; Wang, Zhiming; Huang, Hui; Deliomeroglu, Murat K; Zhukhovitskiy, Aleksandr; Facchetti, Antonio; Marks, Tobin J

    2009-04-22

    The design, synthesis, and characterization of new high-performance n-channel molecular/polymeric semiconductors that are solution-processable and air-stable is of great interest for the development of p-n junctions, bipolar transistors, and organic complementary circuitry (CMOS). While over the past two decades there have been many reports on n-channel materials, solution-processability and air-stability still remain as major challenges. We report here the synthesis and detailed characterization of a highly electron-deficient class of indeno[1,2-b]fluorene-6,12-dione, 2,2'-(indeno[1,2-b]fluorene-6,12-diylidene) dimalononitrile, bisindenofluorene-12,15-dione, and 2,2'-(bisindenofluorene-12,15-diylidene) dimalononitrile-based ladder-type building blocks (1-12) and their corresponding homo- and copolymers (P1-P14), and examine in detail the effects of core size, thiophene vs core regiochemistry, carbonyl vs dicyanovinylene functionality, and alkyl chain orientation on the physicochemical properties, thin film microstructures, and OFET device performance. New compounds are characterized by DSC, TGA, melting point, single-crystal X-ray diffraction (XRD), solution/thin film optical, PL, and cyclic voltammetry measurements to evaluate frontier molecular orbital energetics and intermolecular cohesive forces. Thin films are grown by vacuum deposition and spin-coating, and investigated by X-ray diffraction (XRD) and AFM. By tuning the HOMO/LUMO energetics of the present materials over a 1.1 eV range, p-type, n-type, or ambipolar charge transport characteristics can be observed, thus identifying the MO energetic windows governing majority carrier polarity and air stability. One of these systems, thiophene-terminated indenofluorenedicyanovinylene 10 exhibits an electron mobility of 0.16 cm(2)/V x s and an I(on)/I(off) ratio of 10(7)-10(8), one of the highest to date for a solution-cast air-stable n-channel semiconductor. Here we also report solution-processed ambipolar films

  3. Evaluation of Juvenile Fish Bypass and Adult Fish Facilities at Water Diversions in the Umatilla River; 1992 Annual Report.

    Knapp, Suzanne M.

    1993-03-01

    We report on our progress from October 1991 through September 1992 in evaluating juvenile fish bypass facilities at Three Mile Falls and Westland dams on the Umatilla River. We also report on our progress from October 1991 through June 1992 in evaluating adult fish passage in the lower Umatilla River and adult fish passage facilities at Three Mile Falls Dam. The study is a cooperative effort by the Oregon Department of Fish and Wildlife (ODFW) and the Confederated Tribes of the Umatilla Indian Reservation (CTUIR). These are the study objectives addressed by ODFW and CTUIR: (1) Report A (ODFW): To evaluate the juvenile fish bypass facility in the West Extension Irrigation District Canal at Three Mile Falls Dam and document juvenile salmonid passage through the juvenile fish bypass facility and east-bank adult fish ladder. To measure velocity and develop trap designs at Westland Dam. (2) Report B (CTUIR): To examine the passage of adult salmonids at Three Mile Falls Dam. The study is part of a program to rehabilitate anadromous fish stocks in the Umatilla River Basin, including restoration of coho salmon (Oncorhynchus kisutch) and chinook salmon (Oncorhynchus tshawytscha), as well as enhancement of summer steelhead (Oncorhynchus mykiss).

  4. Design and implementation of a new autonomous sensor fish to support advanced hydropower development

    Deng, Z. D.; Lu, J.; Myjak, M. J.; Martinez, J. J.; Tian, C.; Morris, S. J.; Carlson, T. J.; Zhou, D.; Hou, H.

    2014-11-01

    Acceleration in development of additional conventional hydropower requires tools and methods to perform laboratory and in-field validation of turbine performance and fish passage claims. The new-generation Sensor Fish has been developed with more capabilities to accommodate a wider range of users over a broader range of turbine designs and operating environments. It provides in situ measurements of three-dimensional (3D) linear accelerations, 3D rotational velocities, 3D orientation, pressure, and temperature at a sampling frequency of 2048 Hz. It also has an automatic floatation system and built-in radio-frequency transmitter for recovery. The relative errors of the pressure, acceleration, and rotational velocity were within ±2%, ±5%, and ±5%, respectively. The accuracy of orientation was within ±4° and accuracy of temperature was ±2 °C. The new-generation Sensor Fish is becoming a major technology and being deployed for evaluating the conditions for fish passage of turbines or other hydraulic structures in both the United States and several other countries.

  5. Optimal Design and Numerical Simulation on Fish-Like Flexible Hydrofoil Propeller

    Xue Gang

    2016-12-01

    Full Text Available Hydrofoil is widely used in underwater vehicle for the excellent hydrodynamic characteristics. Currently, researches are mostly about the rigid hydrofoil while the flexible hydrofoil, like the caudal fin, has not been studied adequately. In this paper, the fish was regarded as the bionic object. Then the kinematics model to describe the fish swimming was put forward. A fin-peduncle propulsion mechanism was designed based on the kinematics model to achieve the similar sine curve swimming model. The propulsion mechanism was optimized by Matlab to reduce the deviation between the output curve of the fin-peduncle propulsion mechanism and the ideal motion trajectory. Moreover, the motion phase angles among flexible articulations are optimized to reduce fluid resistance and improve propulsive efficiency. Finally, the fish-like hydrofoil oscillation is simulated by fluid-solid coupling method based on the Fluent. It was shown that the optimized flexible fish-like oscillation could generate the motion that follows the similar law of sine. The propulsive efficiency of oscillating hydrofoil propeller is much higher than that of the screw propeller, and the flexible oscillation has higher propulsive efficiency than the rigid oscillation without obvious fluid resistance increase.

  6. Ising Model on an Infinite Ladder Lattice

    2007-01-01

    In this paper we propose an Ising model on an infinite ladder lattice, which is made of two infinite Ising spin chains with interactions. It is essentially a quasi-one-dimessional Ising model because the length of the ladder lattice is infinite, while its width is finite. We investigate the phase transition and dynamic behavior of Ising model on this quasi-one-dimessional system. We use the generalized transfer matrix method to investigate the phase transition of the system. It is found that there is no nonzero temperature phase transition in this system. At the same time, we are interested in Glauber dynamics. Based on that, we obtain the time evolution of the local spin magnetization by exactly solving a set of master equations.

  7. Ladder Forms in Estimation and System Identification.

    1977-01-01

    system identification . Many record applications, such as in geophysical signal processing, high resolution (’maximum entropy’) spectral estimation and speech encoding, justify the interest in these forms. They appear in many contexts, such as scattering and network theory and the theory of orthogonal polynomials. The state-space model ladder realizations are very closely related in (block) Schwarz matrix canonical forms, which generally appear in the context of stability analysis. In fact they are the natural ’stability canonical form’ for

  8. Braess like Paradox on Ladder Network

    Toyota, Norihito

    2015-01-01

    Braess \\cite{1} has been studied about a traffic flow on a diamond type network and found that introducing new edges to the networks always does not achieve the efficiency. Some researchers studied the Braess' paradox in similar type networks by introducing various types of cost functions. But whether such paradox occurs or not is not scarcely studied in complex networks except for Dorogovtsev-Mendes network\\cite{2}. In this article, we study the paradox on Ladder type networks, as the first step to the research about Braess' paradox on Watts and Strogatz type small world network\\cite{Watt1}\\cite{Watt2}. %We theoretically and numerically studied Braess' paradox on Ladder networks. For the purpose, we construct $4 \\times 3$ models as extensions of the original Braess' models. We analyze theoretically and numerically studied the models on Ladder networks. Last we give a phase diagram for (a) model, where the cost functions of bypasses are constant =0 or flow, base on two parameters $r$ and $p$ by numerical simu...

  9. Dispersal patterns of coastal fish: implications for designing networks of marine protected areas.

    Antonio Di Franco

    Full Text Available Information about dispersal scales of fish at various life history stages is critical for successful design of networks of marine protected areas, but is lacking for most species and regions. Otolith chemistry provides an opportunity to investigate dispersal patterns at a number of life history stages. Our aim was to assess patterns of larval and post-settlement (i.e. between settlement and recruitment dispersal at two different spatial scales in a Mediterranean coastal fish (i.e. white sea bream, Diplodus sargus sargus using otolith chemistry. At a large spatial scale (∼200 km we investigated natal origin of fish and at a smaller scale (∼30 km we assessed "site fidelity" (i.e. post-settlement dispersal until recruitment. Larvae dispersed from three spawning areas, and a single spawning area supplied post-settlers (proxy of larval supply to sites spread from 100 to 200 km of coastline. Post-settlement dispersal occurred within the scale examined of ∼30 km, although about a third of post-settlers were recruits in the same sites where they settled. Connectivity was recorded both from a MPA to unprotected areas and vice versa. The approach adopted in the present study provides some of the first quantitative evidence of dispersal at both larval and post-settlement stages of a key species in Mediterranean rocky reefs. Similar data taken from a number of species are needed to effectively design both single marine protected areas and networks of marine protected areas.

  10. Dispersal patterns of coastal fish: implications for designing networks of marine protected areas.

    Di Franco, Antonio; Gillanders, Bronwyn M; De Benedetto, Giuseppe; Pennetta, Antonio; De Leo, Giulio A; Guidetti, Paolo

    2012-01-01

    Information about dispersal scales of fish at various life history stages is critical for successful design of networks of marine protected areas, but is lacking for most species and regions. Otolith chemistry provides an opportunity to investigate dispersal patterns at a number of life history stages. Our aim was to assess patterns of larval and post-settlement (i.e. between settlement and recruitment) dispersal at two different spatial scales in a Mediterranean coastal fish (i.e. white sea bream, Diplodus sargus sargus) using otolith chemistry. At a large spatial scale (∼200 km) we investigated natal origin of fish and at a smaller scale (∼30 km) we assessed "site fidelity" (i.e. post-settlement dispersal until recruitment). Larvae dispersed from three spawning areas, and a single spawning area supplied post-settlers (proxy of larval supply) to sites spread from 100 to 200 km of coastline. Post-settlement dispersal occurred within the scale examined of ∼30 km, although about a third of post-settlers were recruits in the same sites where they settled. Connectivity was recorded both from a MPA to unprotected areas and vice versa. The approach adopted in the present study provides some of the first quantitative evidence of dispersal at both larval and post-settlement stages of a key species in Mediterranean rocky reefs. Similar data taken from a number of species are needed to effectively design both single marine protected areas and networks of marine protected areas.

  11. Artisanal fishing net float loss and a proposal for a float design solution

    Paulo de Tarso Chaves

    2016-03-01

    Full Text Available Abstract Plastic floats from fishing nets are commonly found washed up on beaches in southern Brazil. They are usually broken and show signs of having been repaired. Characteristics of floats and interviews with fishermen suggest two main causes of float loss. First, collisions between active gear, bottom trawl nets for shrimp, and passive gear, drift nets for fish, destroy nets and release fragments of them, including floats. Second, the difficulty with which floats are inserted on the float rope of the nets when they are used near the surface. Floats are inserted to replace damaged or lost floats, or they may be removed if it is desired that the nets be used in deeper waters. Floats may thus be poorly fixed to the cables and lost. Here a new float design that offers greater safety in use and for the replacement of floats is described and tested.

  12. Fish canning wastewater treatment by activated sludge: Application of factorial design optimization

    Raquel O. Cristóvão

    2015-06-01

    Full Text Available The optimization of hydraulic retention time (HRT and initial organic matter concentration for dissolved organic carbon (DOC abatement of wastewater from a fish canning industry of northern Portugal by activated sludge was investigated using response surface methodology (RSM. The two parameters were chosen since it was found that the treatment efficiency is mainly influenced by them. The experimental data on DOC removal were fitted into a quadratic polynomial model using factorial design and RSM. The optimum process conditions were determined by analyzing the response surface of a three-dimensional plot and by solving the regression model equation. The obtained results showed a HRT of 6.4 h and an initial DOC of 406.2 mg/L as the best treatment conditions. Under these conditions, the maximum predicted DOC removal was 88.0%, confirming the feasibility and the reliability of fish canning wastewater treatment by activated sludge for organic content removal.

  13. Hood River and Pelton Ladder Evaluation Studies, Annual Report 2000-2001.

    Olsen, Erik

    2009-09-01

    The Bonneville Power Administration (BPA) funded the development of two master plans which outline the rationale, and general approach, for implementing a defined group of projects that are an integral part of a comprehensive watershed goal to 'Protect, enhance and restore wild and natural populations of anadromous and resident fish within the Hood River Subbasin'. The Hood River Production Master Plan and the Pelton Ladder Master Plan were completed in 1991 and subsequently approved by the Northwest Power Planning Council in 1992. Action items identified in the two master plans, as well as in a later document entitled 'Hood River/Pelton Ladder Master Agreement' (ODFW and CTWSRO Undated), are designed to achieve two biological fish objectives: (1) to increase production of wild summer and winter steelhead (Oncorhynchus mykiss) to levels commensurate with the subbasins current carrying capacity and (2) re-establishing a self-sustaining population of spring chinook salmon (Oncorhynchus tshawytscha). Numerical fish objectives for subbasin escapement, spawner escapement, and subbasin harvest are defined for each of these species in Coccoli (2000). Several projects are presently funded by the BPA to achieve the Hood River subbasin's numerical fish objectives for summer and winter steelhead and spring chinook salmon. They include BPA project numbers 1998-021-00 (Hood River Fish Habitat), 1998-053-03 (Hood River Production Program - CTWSRO: M&E), 1998-053-07 (Parkdale Fish Facility), 1998-053-08 (Powerdale/Oak Springs O&M), and 1998-053-12 (Hood River Steelhead Genetics Study). Collectively, they are implemented under the umbrella of what has come to be defined as the Hood River Production Program (HRPP). The HRPP is jointly implemented by the Oregon Department of Fish and Wildlife (ODFW) and The Confederated Tribes of the Warm Springs Reservation of Oregon (CTWSRO). Strategies for achieving the HRPP's biological fish objectives for the Hood

  14. SYNTHESIS AND CHARACTERIZATION OF AN ORDERED LADDER POLYESTER

    Ping-ping Zhang; Tao-yi Zhang; Chuan-feng Zhu; Yu-xia Diao; You-zhi Wan; Ping Xie; Rong-ben Zhang

    2006-01-01

    An ordered ladder polyester (LPE) was first synthesized through the ladder superstructure (LS) constructed by concerted interactions of hydroxyl- and aramide-based H-bonding and p-terphenyl (TP)-based π-stacking by dehydrochlorination condensation using phosgene (COCl2) as coupling agent. LPE was characterized by GPC, FTIR, NMR,XRD, DSC and AFM. Among them, a distinct image of regularly linear alignment corresponding to the ladder main chain of LPE was first revealed by high-resolution AFM.

  15. Fish Dishes.

    Derby, Marie

    2003-01-01

    Describes an art project that was inspired by Greek pottery, specifically dishes shaped as fish. Explains that fourth-grade students drew a fish shape that was later used to create their clay version of the fish. Discusses how the students examined the pottery to make decisions about color and design. (CMK)

  16. Design a light pattern of multiple concentric circles for LED fishing lamps using Fourier series and an energy mapping method.

    Shen, S C; Li, J S; Huang, M C

    2014-06-02

    Fourier series and an energy mapping method were used in this study to design a lens that produces a light pattern of multiple concentric circles (LPMCC) for a light-emitting diode (LED) fishing lamp. Fourier series were used to represent the light intensity distribution curve (LIDC) of the LPMCC light pattern. Energy mapping involves performing angular energy mapping based on the LIDCs of an LED light source and LPMCC to design a freeform lens. Type I and Type II LPMCC lenses were designed according to the phototaxis behavior of fish to create a LPMCC light pattern of interleaving light-dark zones that attracts fish shoals to stay in an area for a long period. The experimental results indicated that, in comparing the LIDCs of the Type I and II lenses with the respective simulation values, the normalized cross-correlation (NCC) value reached 96%. According to a 24-hour observation of the phototaxis of Poecilia reticulata to evaluate the effectiveness of the proposed light pattern to attract fish, when a fish shoal was habituated to a light source that emitted constant illumination light, it gradually moved away from the intense light zone and hovered around the junction of the light and dark zones. In the future, the design used in this study can be applied to LED fishing lamps to replace traditional fishing lamps.

  17. Dynamic analysis of rail transit elevated bridge with ladder track

    He XIA; Yushu DENG; Yongwei ZOU; Guido DE ROECK; Geert DEGRANDE

    2009-01-01

    In this paper, a dynamic analysis model of an elevated bridge with ladder tracks under moving train load is established. The whole process of a train running through an elevated bridge at different speeds is simulated.The dynamic responses of the elevated bridge with ladder track and the running safety and comfort index of train vehicles are evaluated. Compared with the dynamic responses of an elevated bridge with ordinary non-ballasted slab track, the ladder track's effect on reducing the vibration of an elevated bridge is analyzed. The analysis results show that the ladder track has good vibration reduction characteristics as compared to ordinary non-ballasted track.

  18. NB Power`s fish handling facilities

    Hickman, C. N. [New Brunswick Power, Fredericton, NB (Canada)

    1995-12-31

    Fish handling facilities at the various hydroelectric power generating stations of New Brunswick Power on the St. John River, were described. The facilities described included the fish hoist at the Beechwood Generating Station , the fish ladder at the Tobique Generating Station and a trap and truck operation at the Mactaquac Station. Details of operating arrangements were provided. Operating issues, solutions and ongoing efforts to improve operations further, were discussed. 4 refs., 4 figs.

  19. Hood River and Pelton Ladder Evaluation Studies, Annual Report 2000-2001.

    Olsen, Erik

    2009-09-01

    The Bonneville Power Administration (BPA) funded the development of two master plans which outline the rationale, and general approach, for implementing a defined group of projects that are an integral part of a comprehensive watershed goal to 'Protect, enhance and restore wild and natural populations of anadromous and resident fish within the Hood River Subbasin'. The Hood River Production Master Plan and the Pelton Ladder Master Plan were completed in 1991 and subsequently approved by the Northwest Power Planning Council in 1992. Action items identified in the two master plans, as well as in a later document entitled 'Hood River/Pelton Ladder Master Agreement' (ODFW and CTWSRO Undated), are designed to achieve two biological fish objectives: (1) to increase production of wild summer and winter steelhead (Oncorhynchus mykiss) to levels commensurate with the subbasins current carrying capacity and (2) re-establishing a self-sustaining population of spring chinook salmon (Oncorhynchus tshawytscha). Numerical fish objectives for subbasin escapement, spawner escapement, and subbasin harvest are defined for each of these species in Coccoli (2000). Several projects are presently funded by the BPA to achieve the Hood River subbasin's numerical fish objectives for summer and winter steelhead and spring chinook salmon. They include BPA project numbers 1998-021-00 (Hood River Fish Habitat), 1998-053-03 (Hood River Production Program - CTWSRO: M&E), 1998-053-07 (Parkdale Fish Facility), 1998-053-08 (Powerdale/Oak Springs O&M), and 1998-053-12 (Hood River Steelhead Genetics Study). Collectively, they are implemented under the umbrella of what has come to be defined as the Hood River Production Program (HRPP). The HRPP is jointly implemented by the Oregon Department of Fish and Wildlife (ODFW) and The Confederated Tribes of the Warm Springs Reservation of Oregon (CTWSRO). Strategies for achieving the HRPP's biological fish objectives for the Hood

  20. Design and control of an embedded vision guided robotic fish with multiple control surfaces.

    Yu, Junzhi; Wang, Kai; Tan, Min; Zhang, Jianwei

    2014-01-01

    This paper focuses on the development and control issues of a self-propelled robotic fish with multiple artificial control surfaces and an embedded vision system. By virtue of the hybrid propulsion capability in the body plus the caudal fin and the complementary maneuverability in accessory fins, a synthesized propulsion scheme including a caudal fin, a pair of pectoral fins, and a pelvic fin is proposed. To achieve flexible yet stable motions in aquatic environments, a central pattern generator- (CPG-) based control method is employed. Meanwhile, a monocular underwater vision serves as sensory feedback that modifies the control parameters. The integration of the CPG-based motion control and the visual processing in an embedded microcontroller allows the robotic fish to navigate online. Aquatic tests demonstrate the efficacy of the proposed mechatronic design and swimming control methods. Particularly, a pelvic fin actuated sideward swimming gait was first implemented. It is also found that the speeds and maneuverability of the robotic fish with coordinated control surfaces were largely superior to that of the swimming robot propelled by a single control surface.

  1. Designing and validating the methodology for the Internet assessment of fish consumption at a university setting

    Erika da Silva Maciel

    2014-06-01

    Full Text Available Assessing fish consumption is complex and involves several factors; however, the use of questionnaires in surveys and the use of the Internet as tool to collect data have been considered promising approaches. Therefore, the objective of this research was to design a data collection technique using a questionnaire to assess fish consumption by making it available on a specific home page on the Internet. A bibliographical survey or review was carried out to identify the features of the instrument, and therefore pre-tests were conducted with previous instruments, followed by the Focus Group technique. Specialists then performed an analysis and conducted an online pre-test. Multivariate data analysis was applied using the SmartPLS software. The results indicate that 1.966 participants belonging to the University of São Paulo (USP community participated in the test, and after the exclusion of some variables, a statistically significant results were obtained. The final constructs comprised consumption, quality, and general characteristics. The instrument consisted of behavioral statements in a 5-point Likert scale and multiple-choice questions. The Cronbach's alpha reliability coefficient was 0.66 for general characteristics, 0.98 for quality, and 0.91 for consumption, which indicate good reliability of the instrument. In conclusion, the results proved that the Internet assessment is efficient. The instrument of analysis allowed us to better understand the process of buying and consuming fish in the country, and it can be used as base for further research.

  2. Healthcare organization-education partnerships and career ladder programs for health care workers.

    Dill, Janette S; Chuang, Emmeline; Morgan, Jennifer C

    2014-12-01

    Increasing concerns about quality of care and workforce shortages have motivated health care organizations and educational institutions to partner to create career ladders for frontline health care workers. Career ladders reward workers for gains in skills and knowledge and may reduce the costs associated with turnover, improve patient care, and/or address projected shortages of certain nursing and allied health professions. This study examines partnerships between health care and educational organizations in the United States during the design and implementation of career ladder training programs for low-skill workers in health care settings, referred to as frontline health care workers. Mixed methods data from 291 frontline health care workers and 347 key informants (e.g., administrators, instructors, managers) collected between 2007 and 2010 were analyzed using both regression and fuzzy-set qualitative comparative analysis (QCA). Results suggest that different combinations of partner characteristics, including having an education leader, employer leader, frontline management support, partnership history, community need, and educational policies, were necessary for high worker career self-efficacy and program satisfaction. Whether a worker received a wage increase, however, was primarily dependent on leadership within the health care organization, including having an employer leader and employer implementation policies. Findings suggest that strong partnerships between health care and educational organizations can contribute to the successful implementation of career ladder programs, but workers' ability to earn monetary rewards for program participation depends on the strength of leadership support within the health care organization.

  3. Using career ladders to motivate and retain employees: an implementation success story.

    Garletts, Joseph A

    2002-01-01

    In October 2000, Phoenix-based Sonora Quest Laboratories, LLC (SQL), commissioned The Gelfond Group to survey SQL employees. Responding to negative survey scores, SQL developed and implemented an entry-level career ladder for line staff of the specimen management/referral testing department. The program was piloted in February 2001, and was implemented fully shortly thereafter. The ladder was designed to provide job enrichment opportunities through company-conducted training and advancement provisions. It contained requirements for productivity and quality of work performed in addition to increasingly rigorous training and competency documentation. Employees were accountable for their own advancement and for ensuring that all documentation was complete. Advancement was automatic once requirements were completed. Pay increases accompanied each advancement on a predetermined scale. At the end of 12 months, employee turnover dropped from 39% to less than 20% annually. Both productivity and morale improved, and results on a second employee survey indicated dramatic improvement in five key areas. The career ladder concept has been replicated successfully in several other departments, including phlebotomy, and a six-tiered ladder is under development for the clinical laboratory. It will encompass CLA, MLT, and MT positions from entry level to technical coordinator.

  4. Design and fabrication of thin microvascularised polymer matrices inspired from secondary lamellae of fish gills

    Kumar, Prasoon; Gandhi, Prasanna S.; Majumder, Mainak

    2016-04-01

    Gills are one of the most primitive gas, solute exchange organs available in fishes. They facilitate exchange of gases, solutes and ions with a surrounding water medium through their functional unit called secondary lamella. These lamellae through their extraordinary morphometric features and peculiar arrangement in gills, achieve remarkable mass transport properties. Therefore, in the current study, modeling and simulation of convection-diffusion transport through a two dimensional model of secondary lamella and theoretical analysis of morphometric features of fish gills were carried out. Such study suggested an evolutionary conservation of parametric ratios across fishes of different weights. Further, we have also fabricated a thin microvascularised PDMS matrices mimicking secondary lamella by use of micro-technologies like electrospinning. In addition, we have also demonstrated the fluid flow by capillary action through these thin microvascularised PDMS matrices. Eventually, we also illustrated the application of these thin microvascularied PDMS matrices in solute exchange process under capillary flow conditions. Thus, our study suggested that fish gills have optimized parameteric ratios, at multiple length scale, throughout an evolution to achieve an organ with enhanced mass transport capabilities. Thus, these defined parametric ratios could be exploited to design and develop efficient, scaled-up gas/solute exchange microdevices. We also proposed an inexpensive and scalable method of fabrication of thin microvascularised polymer matrices and demonstrated its solute exchange capabilities under capillary flow conditions. Thus, mimicking the microstructures of secondary lamella will enable fabrication of microvascularised thin polymer systems through micro manufacturing technologies for potential applications in filtration, self-healing/cooling materials and bioengineering.

  5. Design optimization of a vaneless ``fish-friendly'' swirl injector for small water turbines

    Airody, Ajith; Peterson, Sean D.

    2015-11-01

    Small-scale hydro-electric plants are attractive options for powering remote sites, as they draw energy from local bodies of water. However, the environmental impact on the aquatic life drawn into the water turbine is a concern. To mitigate adverse consequences on the local fauna, small-scale water turbine design efforts have focused on developing ``fish-friendly'' facilities. The components of these turbines tend to have wider passages between the blades when compared to traditional turbines, and the rotors are designed to spin at much lower angular velocities, thus allowing fish to pass through safely. Galt Green Energy has proposed a vaneless casing that provides the swirl component to the flow approaching the rotor, eliminating the need for inlet guide vanes. We numerically model the flow through the casing using ANSYS CFX to assess the evolution of the axial and circumferential velocity symmetry and uniformity in various cross-sections within and downstream of the injector. The velocity distributions, as well as the pressure loss through the injector, are functions of the pitch angle and number of revolutions of the casing. Optimization of the casing design is discussed via an objective function consisting of the velocity and pressure performance measures.

  6. Designing a mathematical model of management techniques (TQM, BPR in Zahedan , weave fishing net industries

    Dr.Baqer Kord, Dr. Habibollah Salarzehi, Hamed Aramesh, Somayeh Mousavi

    2010-10-01

    Full Text Available Currently reengineering and Total Quality Management (TQM techniques known improvement in organizations. in this research initially a Mathematical model was designed to find out the main factors in relative reengineering and TQM. Based on finding factors of Model, a 40 element questionary formed and the questionnaire distributed among the staff of fishing net factory in a random order, finding by using of SPSS, the data analyzed and concluding Remark shows the installation and acceptance of TQM by using reengineering is possible to the factory.

  7. Thermodynamics of strongly disordered spin ladders

    Yusuf, Eddy; Yang, Kun

    2002-01-01

    We study antiferromagnetic two-leg spin-1/2 ladders with strong bond randomness, using the real space renormalization group method. We find the low-temperature spin susceptibility of the system follows non-universal power laws, and the ground state spin-spin correlation is short-ranged. Our results suggest that there is no phase transition when the bond randomness increases from zero; for strong enough randomness the system is in a Griffith region with divergent spin susceptibility and short-...

  8. 29 CFR 1910.26 - Portable metal ladders.

    2010-07-01

    ...—(1) General. To get maximum serviceability, safety, and to eliminate unnecessary damage of equipment... following rules and regulations are essential to the life of the equipment and the safety of the user. (2... of ladders. (i). A simple rule for setting up a ladder at the proper angle is to place the base...

  9. 29 CFR 1910.25 - Portable wood ladders.

    2010-07-01

    ... user equips them with safety shoes; (xviii) (xix) The user should equip all portable rung ladders with... Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR OCCUPATIONAL SAFETY AND HEALTH STANDARDS Walking-Working Surfaces § 1910.25 Portable wood ladders....

  10. Using ergonomics digital human modeling in evaluation of workplaces design and prevention of occupational hazards onboard fishing vessel

    Zhang, Bing; Álvarez Casado, Enrique; Tello Sandoval, Sonia; Rodríguez Mondelo, Pedro Manuel

    2010-01-01

    This paper seeks to present methods for improving the occupational health and safety of Spanish fishermen, and for redesigning the workplace onboard small fishing vessels. To achieve its objective, the research project was designed in four steps: First, the equipment and procedures for catching, handling, and storing fish was studied. Second, the work postures of all the fishermen were simulated and assessed by using an ergonomic digital human modeling system (ManneQuin Pro). Third, the wo...

  11. A millimeter-wave tunneLadder TWT

    Jacquez, A.; Karp, A.; Wilson, D.; Scott, A.

    1988-01-01

    A millimeter wave traveling wave tube was developed using a dispersive, high impedance forward interaction structure based on a ladder, with non-space harmonic interaction, for a tube with high gain per unit length and high efficiency. The TunneLadder interaction structure combines ladder properties modified to accommodate Pierce gun beam optics in a radially magnetized permanent magnet focusing structure. The development involved the fabrication of chemically milled, shaped ladders diffusion brazed to diamond cubes which are in turn active-diffusion brazed to each ridge of a doubly ridged waveguide. Cold test data are presented, representing the omega-beta and impedance characteristics of the modified ladder circuit. These results were used in small and large signal computer programs to predict TWT gain and efficiency. Actual data from tested tubes verify the predicted performance while providing broader bandwidth than expected.

  12. Chemodiversity of Ladder-Frame Prymnesin Polyethers in Prymnesium parvum.

    Rasmussen, Silas Anselm; Meier, Sebastian; Andersen, Nikolaj Gedsted; Blossom, Hannah Eva; Duus, Jens Øllgaard; Nielsen, Kristian Fog; Hansen, Per Juel; Larsen, Thomas Ostenfeld

    2016-09-23

    Blooms of the microalga Prymnesium parvum cause devastating fish kills worldwide, which are suspected to be caused by the supersized ladder-frame polyether toxins prymnesin-1 and -2. These toxins have, however, only been detected from P. parvum in rare cases since they were originally described two decades ago. Here, we report the isolation and characterization of a novel B-type prymnesin, based on extensive analysis of 2D- and 3D-NMR data of natural as well as 90% (13)C enriched material. B-type prymnesins lack a complete 1,6-dioxadecalin core unit, which is replaced by a short acyclic C2 linkage compared to the structure of the original prymnesins. Comparison of the bioactivity of prymnesin-2 with prymnesin-B1 in an RTgill-W1 cell line assay identified both compounds as toxic in the low nanomolar range. Chemical investigations by liquid chromatography high-resolution mass spectrometry (LC-HRMS) of 10 strains of P. parvum collected worldwide showed that only one strain produced the original prymnesin-1 and -2, whereas four strains produced the novel B-type prymnesin. In total 13 further prymnesin analogues differing in their core backbone and chlorination and glycosylation patterns could be tentatively detected by LC-MS/HRMS, including a likely C-type prymnesin in five strains. Altogether, our work indicates that evolution of prymnesins has yielded a diverse family of fish-killing toxins that occurs around the globe and has significant ecological and economic impact.

  13. Larval dispersal and movement patterns of coral reef fishes, and implications for marine reserve network design.

    Green, Alison L; Maypa, Aileen P; Almany, Glenn R; Rhodes, Kevin L; Weeks, Rebecca; Abesamis, Rene A; Gleason, Mary G; Mumby, Peter J; White, Alan T

    2015-11-01

    Well-designed and effectively managed networks of marine reserves can be effective tools for both fisheries management and biodiversity conservation. Connectivity, the demographic linking of local populations through the dispersal of individuals as larvae, juveniles or adults, is a key ecological factor to consider in marine reserve design, since it has important implications for the persistence of metapopulations and their recovery from disturbance. For marine reserves to protect biodiversity and enhance populations of species in fished areas, they must be able to sustain focal species (particularly fishery species) within their boundaries, and be spaced such that they can function as mutually replenishing networks whilst providing recruitment subsidies to fished areas. Thus the configuration (size, spacing and location) of individual reserves within a network should be informed by larval dispersal and movement patterns of the species for which protection is required. In the past, empirical data regarding larval dispersal and movement patterns of adults and juveniles of many tropical marine species have been unavailable or inaccessible to practitioners responsible for marine reserve design. Recent empirical studies using new technologies have also provided fresh insights into movement patterns of many species and redefined our understanding of connectivity among populations through larval dispersal. Our review of movement patterns of 34 families (210 species) of coral reef fishes demonstrates that movement patterns (home ranges, ontogenetic shifts and spawning migrations) vary among and within species, and are influenced by a range of factors (e.g. size, sex, behaviour, density, habitat characteristics, season, tide and time of day). Some species move marine reserves in tropical marine ecosystems to maximise benefits for conservation and fisheries management for a range of taxa. We recommend that: (i) marine reserves should be more than twice the size of the home

  14. Convergent validation study of the Contemplation Ladder for application via telephone in tobacco users Estudo da validação convergente da Escala de Contemplação Ladder aplicada por telefone em tabagistas

    Mauro Barbosa Terra

    2009-01-01

    Full Text Available OBJECTIVE: This work was designed to validate the Portuguese version of the Contemplation Ladder, whose purpose is to assess the motivational phase to quit smoking among tobacco users using a telephone service. METHOD: A cross-sectional study was conducted in a nationwide drug use information hotline. In order to assess the convergent validation, the correlation between the Contemplation Ladder and the URICA Scale was calculated, which was previously validated. RESULTS: The study included 271 tobacco users. Statistically significant correlations were found between the Contemplation Ladder scores and the scores of the URICA precontemplation (r=-0.16; pOBJETIVO: Este estudo teve como objetivo validar a versão em português da Escala de Contemplação Ladder, que visa verificar o estágio motivacional para parar de fumar em tabagistas, em um serviço de atendimento telefônico. MÉTODO: Um estudo transversal foi conduzido em um serviço de âmbito nacional de informação sobre uso de drogas por telefone. Para avaliação da validação convergente foi calculada a correlação entre a Escala de Contemplação Ladder e a Escala URICA, a qual já foi validada anteriormente. RESULTADOS: O estudo incluiu 271 tabagistas. Foram encontradas correlações estatisticamente significativas entre os escores da Escala de Contemplação Ladder e os escores das subescalas de pré-contemplação (r=-0,16; p<0,01, ação (r=0,15; p<0,01 e manutenção (r=0,18; p<0,01 da URICA. A correlação entre o escore composto da Escala URICA e a Escala de Contemplação Ladder também foi significativa (r=0,31; p<0,01. CONCLUSÃO: Os resultados do nosso estudo sugerem que a Escala de Contemplação Ladder pode ser uma alternativa para a Escala URICA (cuja aplicação dura no máximo 20 minutos, sem se impor uma carga maior de perguntas ao entrevistado. O estudo mostrou evidências de validade convergente da Escala de Contemplação Ladder, quando aplicada por telefone, em

  15. Climbing the Ladder: Experience with Developing a Large Group Genetic Counselor Career Ladder at Children's National Health System.

    Kofman, Laura; Seprish, Mary Beth; Summar, Marshall

    2016-08-01

    Children's National Health System (CNHS) is a not-for-profit pediatric hospital that employs around twenty genetic counselors in a range of specialties, including clinical pediatric, neurology, fetal medicine, research, and laboratory. CNHS lacked a structured system of advancement for their genetic counselors; therefore, a formal career ladder was proposed by the genetic counselors based on years of experience, responsibility, and job performance. This career ladder utilized monetary, academic, and seniority incentives to encourage advancement and continue employment at CNHS. The creation and ultimate approval of the career ladder required direct input from genetic counselors, Department Chairs, and Human Resource personnel. The establishment of a genetic counselor career ladder at CNHS will hopefully benefit the profession of genetic counselors as a whole and allow other facilities to create and maintain their own career ladder to meet the needs of the growing, competitive, field of genetic counseling.

  16. Bioenvironmental Engineering and Environmental Medicine Career Ladders (AFS 907X0 and 908X0).

    1985-12-01

    cine career ladder complete a training program designed for entry level personnel. This program is devided into two parts, with an 8-week course...perform a great number of sanitary support functions. They perform an average of 108 tasks. Common tasks include: prepare AF Forms 977 (Facility...TE) data are available to assist in making various decisions about the adequacy of the STS. There is no pattern of great overlap identified between

  17. Sodium-reduced lean sausages with fish oil optimized by a mixture design approach.

    Marchetti, L; Argel, N; Andrés, S C; Califano, A N

    2015-06-01

    A partial NaCl replacement by KCl and sodium tripolyphosphate on low-fat meat sausages formulated with fish oil was studied using a mixture design. Thermal behavior by modulated differential scanning calorimetry, physicochemical, and textural properties were determined; afterwards they were mathematically modeled as a function of salts content. The thermo-rheological behavior of the different formulations was also studied in a control-stress rheometer. The optimal sodium reduction was found employing a desirability function approach. This formulation was experimentally validated and employed for microstructure analysis by environmental scanning microscopy. The results obtained in this work revealed that partial sodium replacement affected the matrix microstructure, but this change had no impact on sensory acceptability. In comparison with US and Argentinean commercial sausages, our product has 58% and 70% less Na(+) respectively.

  18. Design of Heat Pipe Type Adsorption Ice Maker for Fishing Boats

    王丽伟; 王如竹; 夏再忠; 吴静怡

    2005-01-01

    A heat pipe type adsorption ice maker with two adsorbers for fishing boats is designed by using ammonia as refrigerant and compound of activated carbon-GaG12 as adsorbent. This type of heat pipe adsorber can solve the problem of incompatibility between ammonia, copper, seawater and steel. The working process of the ice maker with 8.7kg adsorbent per bed is simulated. The results show that the optimal semi-cycle time is about 9min at the evaporating temperature of -15℃, where the corresponding cooling power, specific cooling power per kilogram adsorbent SCP and coefficient of refrigerant performance COP are respectively 3.6 kW, 217 W·kg-1 and 0.404.

  19. Magnetizing and heating quantum spin ladders

    Andrey Zheludev

    2008-11-01

    Quasi-one-dimensional quantum spin liquids, such as weakly coupled even-legged S=1/2 spin ladders or spin tubes, have a singlet non-magnetic ground state and gap in the excitation spectrum. Their low-temperature properties can be described in terms of triplet massive quasiparticles. These magnons possess some unique features due to the peculiar topology of one dimension. For example, two-particle interactions totally destroy single-particle states for certain energy and momentum transfers, resulting in the so-called termination of the magnon spectrum. At high field a Bose–Einstein condensation of these magnons produces a `quantum spin solid' phase, where `conventional` antiferromagnetic order coexists with excitations that are totally outside conventional spin wave theory. At finite temperatures strong repulsion between quasiparticles leads to a universal renormalization of their masses and lifetimes. These diverse phenomena are best probed by neutron scattering experiments that directly measure the spin correlation functions and excitation spectra.

  20. Integrable Renormalization I: the Ladder Case

    Ebrahimi-Fard, K; Kreimer, D; Ebrahimi-Fard, Kurusch; Guo, Li; Kreimer, Dirk

    2004-01-01

    In recent years a Hopf algebraic structure underlying the process of renormalization in quantum field theory was found. It led to a Birkhoff factorization for (regularized) Hopf algebra characters, i.e. for Feynman rules. In this work we would like to show that this Birkhoff factorization finds its natural formulation in terms of a classical r-matrix, coming from a Rota-Baxter structure underlying the target space of the regularized Hopf algebra characters. Working in the rooted tree Hopf algebra, the simple case of the Hopf subalgebra of ladder trees is treated in detail. The extension to the general case, i.e. the full Hopf algebra of rooted trees or Feynman graphs is briefly outlined.

  1. Ladder Climbing and Autoresonant Acceleration of Plasma Waves

    Barth, Ido; Fisch, Nathaniel J

    2015-01-01

    Classical plasma waves are predicted to exhibit quantumlike ladder climbing, which is achieved by chirped modulations of the background density. An equivalence with the quantum particle in a box is identified and used to calculate the efficiency and the rate of this effect. In the limit of densely spaced spectrum, ladder climbing transforms into continuous autoresonance; plasmons may then be manipulated by chirped background modulations much like electrons are autoresonantly manipulated by chirped fields. Such ladder climbing and autoresonance effects are also predicted for other classical waves by means of a unifying Lagrangian theory.

  2. Log-concavity of the genus polynomials of Ringel Ladders

    Jonathan L Gross

    2015-10-01

    Full Text Available A Ringel ladder can be formed by a self-bar-amalgamation operation on a symmetric ladder, that is, by joining the root vertices on its end-rungs. The present authors have previously derived criteria under which linear chains of copies of one or more graphs have log-concave genus polyno- mials. Herein we establish Ringel ladders as the first significant non-linear infinite family of graphs known to have log-concave genus polynomials. We construct an algebraic representation of self-bar-amalgamation as a matrix operation, to be applied to a vector representation of the partitioned genus distribution of a symmetric ladder. Analysis of the resulting genus polynomial involves the use of Chebyshev polynomials. This paper continues our quest to affirm the quarter-century-old conjecture that all graphs have log-concave genus polynomials.

  3. Straightforward Procedure for Laboratory Production of DNA Ladder

    Vo Thi Thuong Lan

    2012-01-01

    Full Text Available DNA ladder is commonly used to determine the size of DNA fragments by electrophoresis in routine molecular biology laboratories. In this study, we report a new procedure to prepare a DNA ladder that consists of 10 fragments from 100 to 1000 bp. This protocol is a combination of routinely employed methods: cloning, PCR, and partial digestion with restriction enzymes. DNA fragments of 100 bp with unique restriction site at both ends were self-ligated to create a tandem repeat. Once being cloned, the tandem repeat was rapidly amplified by PCR and partially digested by restriction enzymes to produce a ladder containing multimers of the repeated DNA fragments. Our procedure for production of DNA ladder could be simple, time saving, and inexpensive in comparison with current ones widely used in most laboratories.

  4. THERMODYNAMIC PROPERTIES OF LADDER--LIKE HEISENBERG SYSTEM

    蒋青; 潘可扬

    1993-01-01

    By combining the cumulant expansion method with the double-chain approximation, we study thermodynamic properties of ladder-like He isenberg system. We find the interaction between interchains has different effect in high and low temperature.

  5. 9 CFR 93.902 - Ports designated for the importation of live fish, fertilized eggs, and gametes.

    2010-01-01

    ... (INCLUDING POULTRY) AND ANIMAL PRODUCTS IMPORTATION OF CERTAIN ANIMALS, BIRDS, FISH, AND POULTRY, AND CERTAIN ANIMAL, BIRD, AND POULTRY PRODUCTS; REQUIREMENTS FOR MEANS OF CONVEYANCE AND SHIPPING CONTAINERS Aquatic.... (3) Mexican border ports. Otay Mesa, CA. (b) Designation of other ports. Other ports may...

  6. Structural characterization of the cyclic cystine ladder motif of θ-defensins.

    Conibear, Anne C; Rosengren, K Johan; Harvey, Peta J; Craik, David J

    2012-12-04

    The θ-defensins are, to date, the only known ribosomally synthesized cyclic peptides in mammals, and they have promising antimicrobial bioactivities. The characteristic structural motif of the θ-defensins is the cyclic cystine ladder, comprising a cyclic peptide backbone and three parallel disulfide bonds. In contrast to the cyclic cystine knot, which characterizes the plant cyclotides, the cyclic cystine ladder has not been as well described as a structural motif. Here we report the solution structures and nuclear magnetic resonance relaxation properties in aqueous solution of three representative θ-defensins from different species. Our data suggest that the θ-defensins are more rigid and structurally defined than previously thought. In addition, all three θ-defensins were found to self-associate in aqueous solution in a concentration-dependent and reversible manner, a property that might have a role in their mechanism of action. The structural definition of the θ-defensins and the cyclic cystine ladder will help to guide exploitation of these molecules as structural frameworks for the design of peptide drugs.

  7. On The Ladder Bethe-Salpeter Equation

    Efimov, G V

    2003-01-01

    The Bethe-Salpeter (BS) equation in the ladder approximation is studied within a scalar theory: two scalar fields (constituents) with mass $m$ interacting via an exchange of a scalar field (tieon) with mass $\\mu$. The BS equation is written in the form of an integral equation in the configuration Euclidean $x$-space with the kernel which for stable bound states $M<2m$ is a self-adjoint positive operator. The solution of the BS equation is formulated as a variational problem. The nonrelativistic limit of the BS equation is considered. The role of so-called abnormal states is discussed. The analytical form of test functions for which the accuracy of calculations of bound state masses is better than 1% (the comparison with available numerical calculations is done) is determined. These test functions make it possible to calculate analytically vertex functions describing the interaction of bound states with constituents. As a by-product a simple solution of the Wick-Cutkosky model for the case of massless bound...

  8. Percent Stomach Emptiness in Fish Collections: Sources of Variation and Study Design Implications

    We summarized fish stomach content data from 369,000 fish from 402 species in 1,096 collections made between 1925 and 2009 and report on the percentage of individuals with empty stomachs (PES). The mean PES among all species, locations, habitats, dates, and collection methods was...

  9. Dynamics of blood flow in a microfluidic ladder network

    Maddala, Jeevan; Zilberman-Rudenko, Jevgenia; McCarty, Owen

    The dynamics of a complex mixture of cells and proteins, such as blood, in perturbed shear flow remains ill-defined. Microfluidics is a promising technology for improving the understanding of blood flow under complex conditions of shear; as found in stent implants and in tortuous blood vessels. We model the fluid dynamics of blood flow in a microfluidic ladder network with dimensions mimicking venules. Interaction of blood cells was modeled using multiagent framework, where cells of different diameters were treated as spheres. This model served as the basis for predicting transition regions, collision pathways, re-circulation zones and residence times of cells dependent on their diameters and device architecture. Based on these insights from the model, we were able to predict the clot formation configurations at various locations in the device. These predictions were supported by the experiments using whole blood. To facilitate platelet aggregation, the devices were coated with fibrillar collagen and tissue factor. Blood was perfused through the microfluidic device for 9 min at a physiologically relevant venous shear rate of 600 s-1. Using fluorescent microscopy, we observed flow transitions near the channel intersections and at the areas of blood flow obstruction, which promoted larger thrombus formation. This study of integrating model predictions with experimental design, aids in defining the dynamics of blood flow in microvasculature and in development of novel biomedical devices.

  10. On the Impact of Cepheid Outliers on the Distance Ladder

    Becker, M R; Rozo, E; Marshall, P; Rykoff, E S

    2015-01-01

    Recent work by Efstathiou (2014) highlighted the importance of outliers in the period-luminosity (PL) relation of Cepheid data on the distance ladder. We present a statistical framework designed to address this difficulty, and apply it to the Cepheid data from the Milky Way (MW), the Large Magellanic Cloud (LMC), and the Riess et al. (2011) (hereafter R11) dataset. We consider two possible models of the outlier population in the R11 Cepheid dataset. One of these models exhibits tension between the PL relation of the R11 cepheids and the MW+LMC cepheids, while the other does not. We extend our models to adequately account for tension between the cepheid data sets when appropriate. Our outlier treatment has a significant impact on the distance scales to Supernovae hosts with Cepheid distances, increasing the uncertainty in these distances by a median factor of ~30%. We further find that our Cepheid outlier treatment translates into a modest, but non-negligible increase in the statistical uncertainty of H0, addi...

  11. Real-time fish type recognition in underwater images for sustainable fishing

    Jonsson, Fritjof

    2015-01-01

    It has been investigated if it is possible to selectivly catch farmed salmon (Salmo salar L., 1758) and sea trout (Salmo trutta L., 1758) without disturbing the wild fish. A image analysis software that can separate wild from farmed salmon and salmon from sea trout has been developed. This is interesting since the advent of hydro power stations has obstructed the natural migration of these species to their natal river streams. Even though ladders have been built, fewer fish find their way bac...

  12. Analysis of environmental issues related to small scale hydroelectric development. II. Design considerations for passing fish upstream around dams. Environmental Sciences Division Publication No. 1567

    Hildebrand, S.G. (ed.)

    1980-08-01

    The possible requirement of facilities to move migrating fish upstream around dams may be a factor in determining the feasibility of retrofitting small dams for hydroelectric generation. Basic design considerations are reported that should be evaluated on a site-specific basis if upstream fish passage facilities are being considered for a small scale hydroelectric project (defined as an existing dam that can be retrofitted to generate 25 MW or less). Information on general life history and geographic distribution of fish species that may require passage is presented. Biological factors important in the design of upstream passage facilities are discussed: gas bubble disease, fish swimming speed, oxygen consumption by fish, and diel and photo behavior. Three general types of facilities (fishways, fish locks, and fish lifts) appropriate for upstream fish passage at small scale hydroelectric projects are described, and size dimensions are presented. General design criteria for these facilities (including fish swimming ability and behavior) and general location of facilities at a site are discussed. Basic cost considerations for each type of passage facility, including unit cost, operation and maintenance costs, and costs for supplying attraction water, are indicated.

  13. Stomach emptiness in fishes: Sources of variation and study design implications

    Vinson, M.R.; Angradi, T.R.

    2011-01-01

    This study summarizes fish stomach content data from 369,000 fish from 402 species in 1,096 collections and reports on the percentage of individuals with empty stomachs. The mean percentage of individuals with empty stomachs among all species, locations, habitats, seasons, regions, and collection methods was 26.4%. Mean percentage of individuals with empty stomachs varied significantly among fish collection gear types, taxonomic orders, trophic groups, feeding behaviors, and habitats, and with species length at maturity. Most of the variation in percentage of individuals with empty stomachs was explained by species length at maturity, fish collection gear type, and two autecological factors: trophic group (piscivore percentage of individuals with empty stomachs > non-piscivore percentage of individuals with empty stomachs) and feeding habitat (water column feeder percentage of individuals with empty stomachs > benthic feeder percentage of individuals with empty stomachs). After accounting for variation with fish length, the percentage of individuals with empty stomachs did not vary with the stomach removal collection method (dissection vs. gastric lavage), feeding time (diurnal or nocturnal), or time of collection (day or night). The percentage of individuals with empty stomachs was similar between fresh and saltwater fish, but differed within finer habitat classifications and appeared to follow a general prey availability or productivity gradient: percentage of individuals with empty stomachs of open ocean collections > estuary collections, lentic > lotic, and pelagic > littoral. Gear type (active or passive) was the most influential factor affecting the occurrence of empty stomachs that can be readily controlled by researchers.

  14. PT-symmetric ladders with a scattering core

    D' Ambroise, J. [Department of Mathematics, Amherst College, Amherst, MA 01002-5000 (United States); Lepri, S. [CNR – Consiglio Nazionale delle Ricerche, Istituto dei Sistemi Complessi, via Madonna del piano 10, I-50019 Sesto Fiorentino (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Firenze, via G. Sansone 1, I-50019 Sesto Fiorentino (Italy); Malomed, B.A. [Department of Physical Electronics, School of Electrical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv 69978 (Israel); Kevrekidis, P.G. [Department of Mathematics and Statistics, University of Massachusetts, Amherst, MA 01003-9305 (United States)

    2014-08-01

    We consider a PT-symmetric chain (ladder-shaped) system governed by the discrete nonlinear Schrödinger equation where the cubic nonlinearity is carried solely by two central “rungs” of the ladder. Two branches of scattering solutions for incident plane waves are found. We systematically construct these solutions, analyze their stability, and discuss non-reciprocity of the transmission associated with them. To relate the results to finite-size wavepacket dynamics, we also perform direct simulations of the evolution of the wavepackets, which confirm that the transmission is indeed asymmetric in this nonlinear system with the mutually balanced gain and loss. - Highlights: • We model a PT-symmetric ladder system with cubic nonlinearity on two central rungs. • We examine non-reciprocity and stability of incident plane waves. • Simulations of wavepackets confirm our results.

  15. The design, hysteresis modeling and control of a novel SMA-fishing-line actuator

    Xiang, Chaoqun; Yang, Hui; Sun, Zhiyong; Xue, Bangcan; Hao, Lina; Asadur Rahoman, M. D.; Davis, Steve

    2017-03-01

    Fishing line can be combined with shape memory alloy (SMA) to form novel artificial muscle actuators which have low cost, are lightweight and soft. They can be applied in bionic, wearable and rehabilitation robots, and can reduce system weight and cost, increase power-to-weight ratio and offer safer physical human-robot interaction. However, these actuators possess several disadvantages, for example fishing line based actuators possess low strength and are complex to drive, and SMA possesses a low percentage contraction and has high hysteresis. This paper presents a novel artificial actuator (known as an SMA-fishing-line) made of fishing line and SMA twisted then coiled together, which can be driven directly by an electrical voltage. Its output force can reach 2.65 N at 7.4 V drive voltage, and the percentage contraction at 4 V driven voltage with a 3 N load is 7.53%. An antagonistic bionic joint driven by the novel SMA-fishing-line actuators is presented, and based on an extended unparallel Prandtl-Ishlinskii (EUPI) model, its hysteresis behavior is established, and the error ratio of the EUPI model is determined to be 6.3%. A Joule heat model of the SMA-fishing-line is also presented, and the maximum error of the established model is 0.510 mm. Based on this accurate hysteresis model, a composite PID controller consisting of PID and an integral inverse (I-I) compensator is proposed and its performance is compared with a traditional PID controller through simulations and experimentation. These results show that the composite PID controller possesses higher control precision than basic PID, and is feasible for implementation in an SMA-fishing-line driven antagonistic bionic joint.

  16. [Identification of fish species based on ribosomal DNA ITS2 locus].

    Yuan, Wan-An

    2010-04-01

    To prevent illegal fishing and sale, the most difficult problem is identification of marketed fish species, especially the parts that are difficult to be differentiated with morphological method (e.g., larval, eggs, scales, meat, products etc. To assist conservation and management of fishery resources, this paper reported a molecular genetic approach based on ribosomal internal transcribed spacer 2 locus. The method includes two steps: (1) the order general primers were designed according to the conservative nature of 5.8SrRAN and 28SrRNA genes within an order, and the DNA ribosomal internal transcribed spacer 2 locus fragment were then amplified and sequenced. (2) The species-specific ladders and the species-specific primers for each species were designed according to the sequencing results. The map of molecular taxonomy was constructed. This approach employs multiplex PCR that is formatted for fish species identification. We tested 210 single-species samples and 40 mix-species samples from different regions of China. The approach distinguished accurately and sensitively samples from each of the five species. This genetic and molecular approach will be useful for fish conservation, assessment, management and exploitation, strengthen in law enforcement of fishery manager, combat rare and endangered fish smuggling, and prevent commercial fraud and biological invasion by harmful nonnative species.

  17. Triptycene-based ladder monomers and polymers, methods of making each, and methods of use

    Pinnau, Ingo

    2015-02-05

    Embodiments of the present disclosure provide for a triptycene-based A-B monomer, a method of making a triptycene-based A-B monomer, a triptycene-based ladder polymer, a method of making a triptycene-based ladder polymers, a method of using triptycene-based ladder polymers, a structure incorporating triptycene-based ladder polymers, a method of gas separation, and the like.

  18. DUNDRUM Restriction-Intrusion of Liberty Ladders (DRILL) Audit Toolkit

    Kennedy, Harry G

    2011-09-01

    This series of rating \\'ladders\\' is intended to allow a quantitative and qualitative analysis of the use of restrictive and intrusive interventions as part of the therapeutic management of violence and aggression in psychiatric hospital settings. This is an evolving handbook. The ladders are currently organised to facilitate a behavioural analysis. Context, antecedents, behaviour, interventions, consequences are conceptualised as a series of events organised in temporal sequence so that causes, interactions and effects can be considered. The complexity of analysis possible is limited by the statistical power of the numbers of cases and events available. \\r\

  19. Notebook Positioning by Perceptual Map and Laddering Method

    Mehdi Zaribaf

    2012-01-01

    Full Text Available The purpose of this applied paper is to determine positioning of laptops by perceptual map and laddering method. Data collection method was survey using questionnaire. First by using the views of computer experts of selected brands, including Sony, Acer, Asus, Dell and Msi, 5 among 20 attributes, which were considered more important, were selected through application of factor analysis technique. Then, after classification of these features by laddering technique, they were analyzed by using another questionnaire to determine the position of each brand in the perceptual map. We try to show factors and laptop brands position with regard two factors of price and quality in the resulted perceptual map.

  20. Thermoelectric Properties of Solution-Processed n-Doped Ladder-Type Conducting Polymers

    Wang, Suhao; Sun, Hengda; Ail, Ujwala;

    2016-01-01

    Ladder-type "torsion-free" conducting polymers (e.g., polybenzimidazobenzophenanthroline (BBL)) can outperform "structurally distorted" donor-acceptor polymers (e.g., P(NDI2OD-T2)), in terms of conductivity and thermoelectric power factor. The polaron delocalization length is larger in BBL than...... in P(NDI2OD-T2), resulting in a higher measured polaron mobility. Structure-function relationships are drawn, setting material-design guidelines for the next generation of conducting thermoelectric polymers....

  1. Corrosion Control Specialist Career Ladder AFSC 53530, 53550, 53570, and 53690. Occupational Survey Report.

    Air Force Occupational Measurement Center, Lackland AFB, TX.

    The report describes the results of a detailed occupational survey of the corrosion control career ladder. Responses to a 457-task, time rating inventory from 1,015 personnel (representing 64 percent of the career field) were analyzed to produce seven specific findings and the career ladder structure. The career ladder includes a variety of jobs…

  2. Design of object surveillance system based on enhanced fish-eye lens

    Jianhui Wu; Kuntao Yang; Qiaolian Xiang; Nanyang Zhang

    2009-01-01

    A new method is proposed for the object surveillance system based on the enhanced fish-eye lens and the high speed digital signal processor (DSP). The improved fish-eye lens images an ellipse picture on the charge-coupled device (CCD) surface, which increases both the utilization rate of the 4:3 rectangular CCD and the imaging resolution, and remains the view angle of 183°. The algorithm of auto-adapted renewal background subtraction (ARBS) is also explored to extract the object from the monitoring image. The experimental result shows that the ARBS algorithm has high anti-jamming ability and high resolution, leading to excellent object detecting ability from the enhanced elliptical fish-eye image under varies en-vironments. This system has potential applications in different security monitoring fields due to its wide monitoring space, simple structure, working stability, and reliability.

  3. Lock and Dam No. 9 : Arkansas River, Arkansas : Supplement No. 2 to Design Memorandum No. 1, General Fish and Wildlife Facilities at Holla Bend National Wildlife Refuge

    US Fish and Wildlife Service, Department of the Interior — This supplement is prepared in compliance with instructions included in 2d endorsement ENGCW-EZ dated 9 June 1965 to the transmittal letter for Design Memorandum No....

  4. Essential Fish Habitat (EFH) Areas Protected From Fishing

    National Oceanic and Atmospheric Administration, Department of Commerce — Designated Essential Fish Habitat (EFH) areas where fishing or the use of fishing gears has been restricted or modified in order to minimize the adverse effects of...

  5. Genus distribution of ladder type and cross type graphs

    2009-01-01

    In this paper a method is given to calculate the explicit expressions of embedding genus distribution for ladder type graphs and cross type graphs. As an example, we refind the genus distri- bution of the graph Jn which is the first class of graphs studied for genus distribution where its genus depends on n.

  6. Genus distribution of ladder type and cross type graphs

    WAN LiangXia; FENG KeQin; LIU YanPei; WANG DianJun

    2009-01-01

    In this paper a method is given to calculate the explicit expressions of embedding genus distribution for ladder type graphs and cross type graphs.As an example,we refind the genus distribution of the graph Jn which is the first class of graphs studied for genus distribution where its genus depends on n.

  7. SYNTHESIS AND CHARACTERIZATION OF LADDER-LIKE POLYDECYLSILSESQUIOXANE

    Liao-yun Zhang; Dao-rong Dai; Ze Li; Rong-ben Zhang

    1999-01-01

    Ladder-like polydecylsilsesquioxane (LPDS) was synthesized by a preamminolysis reaction of decyltrichlorosilane with ethylene diamine, followed by hydrolysis and polycondensation reaction. LPDS is soluble in a nonpolar solvent such as heptane and insoluble in a high polar solvent such as methanol. It was charaterized by IR, 1H-NMR, 29Si-NMR, GPC and X-ray diffraction.

  8. Undergraduate Education: An Essential Rung on the Rehabilitation Career Ladder

    Evenson, Tom; Holloway, Linda

    2007-01-01

    This article presents the historical pertinence of undergraduate education to developing a career ladder within the field of vocational rehabilitation. Support for the relevance is presented through the results of an investigation of baccalaureate-level competence and preparation as perceived by graduates of rehabilitation services programs. Job…

  9. Mentoring clinical ladder advancement with a facilitated prep class.

    Winslow, Susan A; Blankenship, Jean

    2007-01-01

    The authors describe a strategy for encouraging participation and overcoming reluctance of staff to participate in an optional professional advancement career ladder program. A facilitated prep class in a computer skills laboratory provides nurses with the framework for completing application requirements in a casual, supportive atmosphere.

  10. Towards flavored bound states beyond rainbows and ladders

    El-Bennich, B; Paracha, M A; de Melo, J P B C

    2013-01-01

    We give a snapshot of recent progress in solving the Dyson-Schwinger equation with a beyond rainbow-ladder ansatz for the dressed quark-gluon vertex which includes ghost contributions. We discuss the motivations for this approach with regard to heavy-flavored bound states and form factors and briefly describe future steps to be taken.

  11. Schroedinger operators with the q-ladder symmetry algebras

    Skorik, Sergei; Spiridonov, Vyacheslav

    1994-01-01

    A class of the one-dimensional Schroedinger operators L with the symmetry algebra LB(+/-) = q(+/-2)B(+/-)L, (B(+),B(-)) = P(sub N)(L), is described. Here B(+/-) are the 'q-ladder' operators and P(sub N)(L) is a polynomial of the order N. Peculiarities of the coherent states of this algebra are briefly discussed.

  12. Education for Sustainability: A Snakes and Ladders Game?

    Daniella Tilbury

    2015-07-01

    Full Text Available How to reference this articleTilbury, D. (2015. Education for Sustainability: A Snakes and Ladders Game?. Foro de Educación, 13(19, 7-10. doi: http://dx.doi.org/10.14516/fde.2015.013.019.000

  13. Space Systems Equipment Maintenance Career Ladder AFSC-309X0.

    1986-09-01

    26 ELECTRONICS PRINCIPLES INVENTORY (EPI) .... ............... .... 31 JOB SATISFACTION ANALYSIS ........... ........... . . . . 32...the-job training) are ade- quately meeting the needs of the career ladder. ELECTRONICS PRINCIPLES INVENTORY (EPI) - An additional source of information...for AFSC 309X0 training developers is the EPI. The EPI is a 1,366 item, knowledge-based inventory which identifies the range of electronics principles personnel

  14. Magnetic interactions in calcium and sodium ladder vanadates

    de Graaf, C; Hozoi, L.; Broer-Braam, Henderika

    2004-01-01

    Magnetic interactions in ladder vanadates are determined with quantum chemical computational schemes using the embedded cluster model approach to represent the material. The available experimental data for calcium vanadate is accurately reproduced and the nature of the interladder interaction is est

  15. Based on the FPGA a key called ladder and lock system design and implementation%基于FPGA的街边身份识别报警系统设计与实现

    胡广洲; 白娜; 张春志

    2016-01-01

    With the progress of the society, people's standard of living has improved greatly;But there is still a crime, and robb-ery, rape and other malignant cases still happen;Many after the occurrence of the vicious crimes, the parties concerned or the masses not timely report, or a crime scene does not have the timely and effective reporting conditions, missed the gold report time, lead to fail to catch the criminal suspect, likely to lead to the suspect will continue to commit crime, to people's life and property caused by the threat of further and losses. Based on this, this design with FPGA as the core control device of street fixed identity alarm system.%随着社会的进步,人们的生活水平有了大幅度的提高;但是犯罪案件却仍然存在,而且抢劫、强奸等恶性案件仍时有发生;很多这种恶性犯罪案件发生后,当事人或群众没有及时的报案,或犯罪现场不具备及时有效的报案条件,错过了黄金的报案时间,导致不能及时地抓捕犯罪嫌疑人,有可能导致此嫌疑人会继续作案,给人们的生命财产造成进一步的威胁及损失。基于此,本设计提出一种以FPGA为核心控制器件的街边固定身份识别报警系统。

  16. Ladder contours are undetectable in the periphery: a crowding effect?

    May, Keith A; Hess, Robert F

    2007-10-29

    We studied the perceptual integration of contours consisting of Gabor elements positioned along a smooth path, embedded among distractor elements. Contour elements either formed tangents to the path ("snakes") or were perpendicular to it ("ladders"). Perfectly straight snakes and ladders were easily detected in the fovea but, at an eccentricity of 6 degrees , only the snakes were detectable. The disproportionate impairment of peripheral ladder detection remained when we brought foveal performance away from ceiling by jittering the orientations of the elements. We propose that the failure to detect peripheral ladders is a form of crowding, the phenomenon observed when identification of peripherally located letters is disrupted by flanking letters. D. G. Pelli, M. Palomares, and N. J. Majaj (2004) outlined a model in which simple feature detectors are followed by integration fields, which are involved in tasks, such as letter identification, that require the outputs of several detectors. They proposed that crowding occurs because small integration fields are absent from the periphery, leading to inappropriate feature integration by large peripheral integration fields. We argue that the "association field," which has been proposed to mediate contour integration (D. J. Field, A. Hayes, & R. F. Hess, 1993), is a type of integration field. Our data are explained by an elaboration of Pelli et al.'s model, in which weak ladder integration competes with strong snake integration. In the fovea, the association fields were small, and the model integrated snakes and ladders with little interference. In the periphery, the association fields were large, and integration of ladders was severely disrupted by interference from spurious snake contours. In contrast, the model easily detected snake contours in the periphery. In a further demonstration of the possible link between contour integration and crowding, we ran our contour integration model on groups of three-letter stimuli

  17. PLUME collaboration: Ultra-light ladders for linear collider vertex detector

    Nomerotski, A., E-mail: A.Nomerotski@physics.ox.ac.uk [University of Oxford, Particle Physics, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH (United Kingdom); Bachynska, O. [DESY Hamburg, Notkestr. 85, D-22607 Hamburg (Germany); Baudot, J.; Chon-Sen, N.; Claus, G.; De Masi, R. [IPHC/IN2P3/CNRS and Universite de Strasbourg, Strasbourg (France); Deveaux, M. [IK-Frankfurt, Goethe-Universitaet, Frankfurt am Main (Germany); Dulinski, W. [IPHC/IN2P3/CNRS and Universite de Strasbourg, Strasbourg (France); Gauld, R. [University of Oxford, Particle Physics, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH (United Kingdom); Goffe, M. [IPHC/IN2P3/CNRS and Universite de Strasbourg, Strasbourg (France); Goldstein, J. [University of Bristol, Tyndall Avenue, Bristol BS8 1TL (United Kingdom); Gregor, I.-M. [DESY Hamburg, Notkestr. 85, D-22607 Hamburg (Germany); Hu-Guo, Ch.; Imhoff, M. [IPHC/IN2P3/CNRS and Universite de Strasbourg, Strasbourg (France); Koetz, U. [DESY Hamburg, Notkestr. 85, D-22607 Hamburg (Germany); Lau, W. [University of Oxford, Particle Physics, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH (United Kingdom); Muntz, C. [IK-Frankfurt, Goethe-Universitaet, Frankfurt am Main (Germany); Santos, C. [IPHC/IN2P3/CNRS and Universite de Strasbourg, Strasbourg (France); Schrader, C. [IK-Frankfurt, Goethe-Universitaet, Frankfurt am Main (Germany); Specht, M. [IPHC/IN2P3/CNRS and Universite de Strasbourg, Strasbourg (France); and others

    2011-09-11

    The PLUME (Pixelated Ladder with Ultra-Low Material Embedding) Collaboration is developing ultra-light ladders for the vertex detector for a future linear collider. The double-sided ladder will integrate the sensors, readout infrastructure and mechanical supports with the aim of total material budget of 0.3% of radiation length. The requirement of as light as possible construction is driven by physics, in particular by measurements requiring determination of the quark charge sign. The first prototype ladders were prepared and tested in the beam. The alignment issues for the ladders will be tested within the AIDA (Advanced European Infrastructures for Detectors at Accelerators) EU FP7 project.

  18. Changing How Schools and the Profession Are Organized: Building a Foundation for a National System of Teacher Career Ladders at the National Center on Education and the Economy

    Yang Keo, Seng-Dao

    2016-01-01

    This capstone examines the National Center on Education and the Economy’s (NCEE) efforts in its initial planning stage to lead the design of and build support for a proposed national system of teacher career ladders. In this career ladder system, teachers can voluntarily seek advanced certification leading up to the role of Master Teacher, and states can volunteer to use the system and determine how to use it. I describe my role in strengthening NCEE’s relationship with the National Board for...

  19. Means – End Chain Theory and Laddering Technique: Applications in Consumer Behavior Research

    Ayca Kangal

    2013-04-01

    Full Text Available Means – end chain (MEC theory and laddering technique uncovers the decision making process of consumers related to marketing offerings such as goods, services and experiences in a cognitive approach from a consumer perspective view which are popularly used approaches in marketing context. The purpose of the study is to discusss and present the laddering techique to Turkish literature, which is a frequently used qualitative research method in consumer behavior, both with related theoretical structure and practice. With this purpose, the overview of the literature within the frame of means – end chain theory, practices in consumer behavior, laddering technique, data collection, data analyze and interperation steps, limits of the laddering technique and alternatives of soft laddering (hard laddering is discussed. Laddering technique among with alternative data collection tools are anticipated Turkish researchers’ interest.

  20. New phenazine-containing ladder polymer of intrinsic microporosity from a spirobisindane-based AB-type monomer

    Ghanem, Bader

    2016-08-15

    A new solution-processable ladder polymer (PSBI-AB) of intrinsic microporosity with dibenzodioxane linkages and bis(phenazine) units was designed and synthesized by self-polymerization of an AB-type monomer containing both catechol and aromatic dichloride groups. Such polymerization is an effective way to synthesize high molecular weight polymers and has a significant advantage over AA-BB polycondensation due to the lack of the requirement for strict control over stoichiometric balance. This protocol can be used to prepare a variety of phenazine-containing ladder type PIMs from their aromatic tetramethoxy precursors. The obtained polymer had high average molecular mass, excellent thermal stability, a high BET surface area of 705 m(2) g(-1) and good solubility in some organic solvents such as chloroform, m-cresol and dichlorobenzene. Gas permeation measurements showed comparable results to the previously reported analogous PIM-7 for films made under the same formation protocol.

  1. Design and application of a fish-shaped lateral line probe for flow measurement

    Tuhtan, J. A.; Fuentes-Pérez, J. F.; Strokina, N.; Toming, G.; Musall, M.; Noack, M.; Kämäräinen, J. K.; Kruusmaa, M.

    2016-04-01

    We introduce the lateral line probe (LLP) as a measurement device for natural flows. Hydraulic surveys in rivers and hydraulic structures are currently based on time-averaged velocity measurements using propellers or acoustic Doppler devices. The long-term goal is thus to develop a sensor system, which includes spatial gradients of the flow field along a fish-shaped sensor body. Interpreting the biological relevance of a collection of point velocity measurements is complicated by the fact that fish and other aquatic vertebrates experience the flow field through highly dynamic fluid-body interactions. To collect body-centric flow data, a bioinspired fish-shaped probe is equipped with a lateral line pressure sensing array, which can be applied both in the laboratory and in the field. Our objective is to introduce a new type of measurement device for body-centric data and compare its output to estimates of conventional point-based technologies. We first provide the calibration workflow for laboratory investigations. We then provide a review of two velocity estimation workflows, independent of calibration. Such workflows are required as existing field investigations consist of measurements in environments where calibration is not feasible. The mean difference for uncalibrated LLP velocity estimates from 0 to 50 cm/s under in a closed flow tunnel and open channel flume was within 4 cm/s when compared to conventional measurement techniques. Finally, spatial flow maps in a scale vertical slot fishway are compared for the LLP, direct measurements, and 3D numerical models where it was found that the LLP provided a slight overestimation of the current velocity in the jet and underestimated the velocity in the recirculation zone.

  2. NEW DESIGN FOR AIRLIFT PUMP USED IN FISH CULTURE TANKS WITH THE ENDANGERED RIO GRANDE SILVERY MINNOW (Hybognathus amarus

    Alison M. Hutson

    2012-10-01

    Full Text Available This article describes an airlift pump used to produce a circular flow in a fish culture tank that does not attach to the tank. The design produces an airlift pump that does not swing back and forth or float upwards while in use. It is easy to build, inexpensive, and can be quickly installed and removed so that it does not interfere with sampling or harvest. The airlift pump was evaluated during a 30-d survival trial with the endangered Rio Grande silvery minnow (Hybognathus amarus in 2.44-m-diameter circular tanks (3,666 l. Because the fish is endangered, all new culture units must be evaluated in a survival trial. To be able to use a new 15-tank system, survival had to be evaluated in a random representation of three tanks. U.S. Fish and Wildlife Service, which regulates all activities with this endangered species, decided that permitted take (maximum permitted mortality was 60% for the survival trial; consequently, survival >40% in each tank would be considered successful. Two airlift pumps were placed in each tank. The two airlift pumps moved a mean±SD of 33.697±5.563 l/min; this produced total tank turnovers through the airlift pumps of 110.65±16.93 min. Water velocities were measured at nine locations in the tanks. Water velocities were 0.0-0.04 m/sec. Dissolved oxygen concentration never went below 6.30 mg/l. The airlift pumps operated flawlessly and required no maintenance. They produced water velocities preferred by the fish and helped keep dissolved oxygen concentration above the permitted minimum (5 mg/l. The airlift pumps will be used in future fish culture activities in these and other tanks. Survival in the three tanks was 78%, 94% and 96%; overall survival was 89.3%. Because take (10.7% was under the permitted level (60%, the trial was successful.

  3. Design and characterization of self-assembled fish sarcoplasmic protein-alginate nanocomplexes

    Boutrup Stephansen, Karen; Mattebjerg, Maria Ahlm; Wattjes, Jasper;

    2015-01-01

    Macrostructures based on natural polymers are subject to large attention, as the application range is wide within the food and pharmaceutical industries. In this study we present nanocomplexes (NCXs) made from electrostatic self-assembly between negatively charged alginate and positively charged...... fish sarcoplasmic proteins (FSP), prepared by bulk mixing. A concentration screening revealed that there was a range of alginate and FSP concentrations where stable NCXs with similar properties were formed, rather than two exact concentrations. The size of the NCXs was 293 +/- 3 nm, and the zeta...

  4. Using ergonomics Digital Human Modeling in Evaluation of workplace Design and Prevention of work related musculoeskeletal disorders aboard small fishing vessels r

    Álvarez Casado, Enrique; Zhang, Bing; Tello Sandoval, Sonia; Rodríguez Mondelo, Pedro Manuel

    2011-01-01

    This article seeks to presentmethods for preventing work-relatedmusculoskeletal disorders of Spanish fishermen and for redesigning the workplace aboard small fishing vessels. To achieve its objective, the research project was designed in four steps. First, the equipment and procedures for catching, handling, and storing fish were studied. Second, the work postures of all the fishermen were simulated and assessed by using an ergonomic digital human modeling system (ManneQuin Pro). ...

  5. New Design of Crypto-Based Pseudo random number generator (CBPRNG using BLOW FISH cipher

    T.Chalama Reddy

    2013-06-01

    Full Text Available Random Number Generators (RNGs are an important building block for algorithms and protocols in cryptography. Random number generation is used in a wide variety of cryptographic operations, such as key generation and challenge/response protocols. A random number generator outputs a sequence of 0s and 1s such that at any position, the next bit cannot be expected on the previous bits. However, true random number produces non- deterministic output since if the same random generator is run twice, identical results are not received. Thus we go for pseudo random number generator that is deterministic device because if this random number generator is run twice or more, it gives same results. Our paper presents new crypto based pseudorandom number generator. It uses BLOW FISH ciphers and the Cipher-Block chaining (CBC mode that uses three stages of the block chaining. The plain text for each stage comes from the output of the first BLOW FISH, which uses the 64-Bit date and time as the plain text. CBPRNG creates three 64-bit random numbers, the first and the second are concatenated to create a 128-random number and the third is used as next initial vector (IV for CBPRNG. Our Crypto-Based Pseudo-random Number Generator produces a sequence of bits that has arandom looking distribution. This new generator helps to develop huge range cryptographic applications to increase the system security. A number of applications such as financial security applications and Pretty Good Privacy (PGP use this technique.

  6. Designing long-term fish community assessments in connecting channels: Lessons from the Saint Marys River

    Schaeffer, Jeff; Rogers, Mark W.; Fielder, David G.; Godby, Neal; Bowen, Anjanette K.; O'Connor, Lisa; Parrish, Josh; Greenwood, Susan; Chong, Stephen; Wright, Greg

    2014-01-01

    Long-term surveys are useful in understanding trends in connecting channel fish communities; a gill net assessment in the Saint Marys River performed periodically since 1975 is the most comprehensive connecting channels sampling program within the Laurentian Great Lakes. We assessed efficiency of that survey, with intent to inform development of assessments at other connecting channels. We evaluated trends in community composition, effort versus estimates of species richness, ability to detect abundance changes for four species, and effects of subsampling yellow perch catches on size and age-structure metrics. Efficiency analysis revealed low power to detect changes in species abundance, whereas reduced effort could be considered to index species richness. Subsampling simulations indicated that subsampling would have allowed reliable estimates of yellow perch (Perca flavescens) population structure, while greatly reducing the number of fish that were assigned ages. Analyses of statistical power and efficiency of current sampling protocols are useful for managers collecting and using these types of data as well as for the development of new monitoring programs. Our approach provides insight into whether survey goals and objectives were being attained and can help evaluate ability of surveys to answer novel questions that arise as management strategies are refined.

  7. Bethe–Salpeter studies of mesons beyond rainbow-ladder

    Williams R.

    2010-04-01

    Full Text Available We investigate the masses of light mesons from a coupled system of Dyson–Schwinger and Bethe– Salpeter equations. We explicitly take into account dominant non-Abelian and sub-leading Abelian contributions to the dressed quark-gluon vertex. We also include unquenching effects in the form of hadronic resonance contributions via the back-reaction of pions. We construct the corresponding Bethe–Salpeter kernel that satisfies the axial-vector Ward-Takahashi identity. Our numerical treatment fully includes all momentum dependencies with all equations solved completely in the complex plane. This approach goes well beyond the rainbow-ladder approximation and permits us to investigate the relative impact of different corrections beyond rainbow-ladder on the properties of mesons. We find that sub-leading Abelian corrections are further dynamically suppressed, and that our results supersede early qualitative predictions with significantly simpler truncation schemes.

  8. Quantum Phase Transitions and Dimerized Phases in Frustrated Spin Ladder

    WEN Rui; LIU Guang-Hua; TIAN Guang-Shan

    2011-01-01

    In this paper, we study the phase diagram of a frustrated spin ladder model by applying the bosonization technique and the density-matrix renormalization-group (DMRG) algorithm. Effect of the intra-chain next-nearestneighbor (NNN) super-exchange interaction is investigated in detail and the order parameters are calculated to detect the emergence of the dimerized phases. We find that the intra-chain NNN interaction plays a key role in inducing dimerized phases.

  9. Snakes and ladders: localized solutions of plane Couette flow

    Schneider, Tobias M; Burke, John

    2009-01-01

    We demonstrate the existence of a large number of exact solutions of plane Couette flow, which share the topology of known periodic solutions but are localized in space. Solutions of different size are organized in a snakes-and-ladders structure strikingly similar to that observed for simpler pattern-forming PDE systems. These new solutions are a step towards extending the dynamical systems view of transitional turbulence to spatially extended flows.

  10. Laplace-Runge-Lenz vector, ladder operators and supersymmetry

    Mota, R.D. [Unidad Profesional Interdisciplinaria de Ingenieria y Tecnologias Avanzadas, Mexico DF (Mexico)]. E-mail: mota@gina.esfm.ipn.mx; Garcia, J.; Granados, V.D. [Departamento de Fisica, Escuela Superior de Fisica y Matematicas, Mexico DF (Mexico)

    2001-03-16

    We show that the Laplace-Runge-Lenz vector (LRLV) generates the Infeld-Hull radial factorization and the pair of isospectral Hamiltonians for the non-relativistic Kepler-Coulomb quantum problem. To do this we only use the LRLV and arguments of general soundness. Finally, the well known restrictions on the orbital angular momentum and the principal quantum numbers are rederived from the corresponding ladder operators. (author)

  11. On the impedance of infinite LC ladder networks

    Klimo, Paul

    2017-01-01

    The subject of electrical impedance is on the syllabi of most undergraduate courses in physics and electrical engineering. For example, Richard Feynman in his famous undergraduate text Lectures on Physics shows how to calculate the impedance of an infinite LC ladder. However, the formula he obtains has no useful physical interpretation if considered in the steady state frequency domain. In fact the value of this impedance becomes infinite unless one assumes that the energy flow along the infinite LC ladder is spatially uniform and in one direction only. This ad-hoc assumption, which renders the solution non-causal, is entirely unnecessary if the problem is considered in the time domain. It is important for students to appreciate that the concept of impedance works well only in dissipative circuits where the effects of transients are largely short lived. The purpose of this paper is to show that the same problem treated in the time domain by the Laplace transform method provides a qualitatively different and more satisfying explanation. We show that the current response of an infinite LC ladder, which is in the zero state before a causal harmonic driving voltage is applied, contains a significant non-harmonic component. This component, which is present in addition to the forced harmonic waveform, decays only very slowly and extracts an infinite amount of energy from the source.

  12. The cyclic cystine ladder of theta-defensins as a stable, bifunctional scaffold: A proof-of-concept study using the integrin-binding RGD motif.

    Conibear, Anne C; Bochen, Alexander; Rosengren, K Johan; Stupar, Petar; Wang, Conan; Kessler, Horst; Craik, David J

    2014-02-10

    Peptides have the specificity and size required to target the protein-protein interactions involved in many diseases. Some cyclic peptides have been utilised as scaffolds for peptide drugs because of their stability; however, other cyclic peptide scaffolds remain to be explored. θ-Defensins are cyclic peptides from mammals; they are characterised by a cyclic cystine ladder motif and have low haemolytic and cytotoxic activity. Here we demonstrate the potential of the cyclic cystine ladder as a scaffold for peptide drug design by introducing the integrin-binding Arg-Gly-Asp (RGD) motif into the θ-defensin RTD-1. The most active analogue had an IC50 of 18 nM for the αv β3 integrin as well as high serum stability, thus demonstrating that a desired bioactivity can be imparted to the cyclic cystine ladder. This study highlights how θ-defensins can provide a stable and conformationally restrained scaffold for bioactive epitopes in a β-strand or turn conformation. Furthermore, the symmetry of the cyclic cystine ladder presents the opportunity to design peptides with dual bioactive epitopes to increase activity and specificity.

  13. Solutions of Bethe-Salpeter and Light-Front equations with cross-ladder kernel

    Carbonell, J

    2005-01-01

    By method developed in our previous paper we solve the Bethe-Salpeter (BS) equation for the kernel given by sum of ladder and cross-ladder exchanges. We solve also corresponding equation in light-front dynamics (LFD), where we add the time-ordered stretched boxes. Cross-ladder contribution is large and attractive, whereas the influence of stretched boxes is negligible. Both approaches -- BS and LFD -- give very close results.

  14. Progress in the Supramolecular Architecture-directed Synthesis of Perfect Ladder Polysiloxanes

    C; C; Han

    2007-01-01

    1 Introduction Ladder polysiloxanes (LPSs) including organo-bridged ladder polyorganosiloxanes (R-OLPSs, R is side group) and ladder polyorganosilsesquioxanes (R-LPSQs) have intrigued polymer chemists for about 50 years due to their excellent resistance to all kinds of degradations. However, their synthesis has been a great challenge to polymer chemists. Here, we describe a new approach based on supramolecular concerted interactions as follows.2 Results2.1 Synthesis of Perfect R-OLPSsA series of real ...

  15. Chain Growth Cross Coupling Polymerizations Towards Chiral and Ladder Main Chain Polymers

    2014-11-20

    SECURITY CLASSIFICATION OF: We developed a new method to synthesize rigid ladder polymers using efficient, clean palladium catalyzed annulation...reactions with low catalyst loading (1 mol%). Rigid ladder polymers with benzocyclobutene backbone linkages can be synthesized from copolymerization of...High molecular weight (10-40 kDa) rigid ladder polymers can be obtained with complete monomer conversions. Diverse monomers also gave different, fixed

  16. Development of ultra-light pixelated ladders for an ILC vertex detector

    Chon-Sen, N; Claus, G; De Masi, R; Deveaux, M; Dulinski, W; Goffe, M; Goldstein, J; Gregor, I -M; Imhoff, Ch Hu-Guo M; Müntz, C; Nomerotski, A; Santos, C; Schrader, C; Specht, M; Stroth, J; Winter, M

    2010-01-01

    The development of ultra-light pixelated ladders is motivated by the requirements of the ILD vertex detector at ILC. This paper summarizes three projects related to system integration. The PLUME project tackles the issue of assembling double-sided ladders. The SERWIETE project deals with a more innovative concept and consists in making single-sided unsupported ladders embedded in an extra thin plastic enveloppe. AIDA, the last project, aims at building a framework reproducing the experimental running conditions where sets of ladders could be tested.

  17. Fish schooling as a basis for vertical axis wind turbine farm design.

    Whittlesey, Robert W; Liska, Sebastian; Dabiri, John O

    2010-09-01

    Most wind farms consist of horizontal axis wind turbines (HAWTs) due to the high power coefficient (mechanical power output divided by the power of the free-stream air through the turbine cross-sectional area) of an isolated turbine. However when in close proximity to neighboring turbines, HAWTs suffer from a reduced power coefficient. In contrast, previous research on vertical axis wind turbines (VAWTs) suggests that closely spaced VAWTs may experience only small decreases (or even increases) in an individual turbine's power coefficient when placed in close proximity to neighbors, thus yielding much higher power outputs for a given area of land. A potential flow model of inter-VAWT interactions is developed to investigate the effect of changes in VAWT spatial arrangement on the array performance coefficient, which compares the expected average power coefficient of turbines in an array to a spatially isolated turbine. A geometric arrangement based on the configuration of shed vortices in the wake of schooling fish is shown to significantly increase the array performance coefficient based upon an array of 16 x 16 wind turbines. The results suggest increases in power output of over one order of magnitude for a given area of land as compared to HAWTs.

  18. Fish Allergy

    ... Old Feeding Your 1- to 2-Year-Old Fish Allergy KidsHealth > For Parents > Fish Allergy Print A ... From Home en español Alergia al pescado About Fish Allergy A fish allergy is not exactly the ...

  19. Improved design of multi-beam underwater acoustic monitoring system for fish in offshore fish cage%深水网箱多波束水声鱼群状态监测仪的改进设计

    彭阳明; 许肖梅; 张小康

    2011-01-01

    针对离岸深水网箱养殖的鱼群安全问题,采用多波束水声技术监测鱼群状态的方法.结合信号处理技术、通用分组无线业务(GPRS)无线传输技术及串口通信技术,开发了一套多波束水声鱼群状态监测仪.监测仪完成1次网箱扫描只需5s;实现了监测数据的即采即发功能,提高了系统的实时性;改进了电路结构,降低了系统复杂度,减小了系统体积,降低了成本.试验表明,监测仪操作简便,性能稳定,能有效完成深水网箱的实时监测任务.%To the security issue of fish shoal in offshore fish cage, a monitoring method based on multi-beam underwater acoustic technique is employed. Integrating with the techniques of signal processing, GPRS wireless data communication and serial interface communication, a multi-beam underwater acoustic monitoring system for breeding fish in offshore fish cage is designed. It takes only five second to accomplish an entire cage scanning. Detecting data are delivered to the user monitoring system immediately upon acquisition, which improves the real-time property of the system. As its circuit is improved, the system structure is simplified. Both the volume and the cost of the monitor is reduced. Tests show that the monitoring system is simplified, easy placement and robust under different environmental conditions. It is well performed in real-time monitoring fish in offshore fish cage.

  20. Yang-Lee Circle Theorem for an Antiferromagnetic Heisenberg Ladder

    王先智

    2001-01-01

    The Yang-Lee zeros of an antiferromagnetic Heisenberg ladder model are determined. It is found that if J4≤0 Yang-Lee zeros are located on the unit circle and on the negative real axis in the complex activity plane. In particular, if J4≤0 and 2J2≥J4, Yang-Lee zeros are located on the unit circle and the Yang-Lee circle theorem is valid. If J4 > 0, Yang-Lee zeros are located on some complicated curves.

  1. Period Halving of Persistent Currents in Mesoscopic Mobius Ladders

    邓文基; 许基桓; 刘平

    2002-01-01

    We investigate the period halving of persistent currents (PCs) of non-interacting electrons in isolated mesoscopicMobius ladders without disorder, pierced by Aharonov-Bohm flux. The mechanisms of the period halving effectdepend on the parity of the number of electrons as well as on the interchain hopping. Although the data of PCsin mesoscopic systems are sample specific, some simple rules are found in the canonical ensemble average, forexample, all the odd harmonics of the PCs disappear and the signals of even harmonics are non-negative.

  2. The phonon and thermal properties of a ladder nanostructure

    M Mardaani

    2011-12-01

    Full Text Available  In this paper, we study the phonon thermal properties of a ladder nanostructure in harmonic approximation. We present a model consisting of two infinite chains with different masses. Then, we investigate the effect of different masses on the phonon spectrum. Moreover, as a specific case, in the absence of the second neighbor interaction, we calculate the phonon density of states/modes. Finally, we consider the thermal conductivity of the system. The results show that the phonon spectrum shifts down to the lower frequencies by increasing the masses. Furthermore, a frequency gap appears in the phonon spectrum. By increasing the springs constants, the thermal conductance decreases.

  3. The QCD gluon ladders and HERA structure function

    Lengyel, A I

    2002-01-01

    We report on the extension of the data fitting considering the QCD inspired model based on the summation of gluon ladders applied to the $ep$ scattering. In lines of a two Pomeron approach, the structure function $F_2$ has a hard piece given by the model and the remaining soft contribution: a soft Pomeron and non-singlet content. In this contribution, we carefully estimate the relative role of the hard and the soft pieces from a global fit in a large span of $x$ and $Q^2$.

  4. Diquark bound states at far beyond ladder truncation

    Jinno, Ryusuke; Mishima, Go

    2015-01-01

    The Bethe-Salpeter equation in the diquark channel is investigated by employing the Dyson-Schwinger method together with the Munczek-Nemirovsky model. The novelty of our study is a resummation of completely-crossed ladder diagrams in the Bethe-Salpeter kernel. These diagrams are enhanced due to their color factors in the diquark channel, but not in the meson channel. As a result of our analysis, it is suggested that diquark bound-state solutions exist in the Bethe-Salpeter equation, which have been thought to be absent.

  5. Valence bond and von Neumann entanglement entropy in Heisenberg ladders.

    Kallin, Ann B; González, Iván; Hastings, Matthew B; Melko, Roger G

    2009-09-11

    We present a direct comparison of the recently proposed valence bond entanglement entropy and the von Neumann entanglement entropy on spin-1/2 Heisenberg systems using quantum Monte Carlo and density-matrix renormalization group simulations. For one-dimensional chains we show that the valence bond entropy can be either less or greater than the von Neumann entropy; hence, it cannot provide a bound on the latter. On ladder geometries, simulations with up to seven legs are sufficient to indicate that the von Neumann entropy in two dimensions obeys an area law, even though the valence bond entanglement entropy has a multiplicative logarithmic correction.

  6. Exact solutions and ladder operators for a new anharmonic oscillator

    Dong Shihai [Programa de Ingenieria Molecular, Instituto Mexicano del Petroleo, Lazaro Cardenas 152, 07730 Mexico DF (Mexico)]. E-mail: dongsh2@yahoo.com; Sun Guohua [Instituto de Investigaciones en Matematicas Aplicadas y en Sistemas, UNAM, A.P. 20-726, Del. Alvaro Obregon, 01000 Mexico DF (Mexico); Lozada-Cassou, M. [Programa de Ingenieria Molecular, Instituto Mexicano del Petroleo, Lazaro Cardenas 152, 07730 Mexico DF (Mexico)

    2005-06-06

    In this Letter, we propose a new anharmonic oscillator and present the exact solutions of the Schrodinger equation with this oscillator. The ladder operators are established directly from the normalized radial wave functions and used to evaluate the closed expressions of matrix elements for some related functions. Some comments are made on the general calculation formula and recurrence relation for off-diagonal matrix elements. Finally, we show that this anharmonic oscillator possesses a hidden symmetry between E(r) and E(ir) by substituting r->ir.

  7. PNA-COMBO-FISH: From combinatorial probe design in silico to vitality compatible, specific labelling of gene targets in cell nuclei.

    Müller, Patrick; Rößler, Jens; Schwarz-Finsterle, Jutta; Schmitt, Eberhard; Hausmann, Michael

    2016-07-01

    Recently, advantages concerning targeting specificity of PCR constructed oligonucleotide FISH probes in contrast to established FISH probes, e.g. BAC clones, have been demonstrated. These techniques, however, are still using labelling protocols with DNA denaturing steps applying harsh heat treatment with or without further denaturing chemical agents. COMBO-FISH (COMBinatorial Oligonucleotide FISH) allows the design of specific oligonucleotide probe combinations in silico. Thus, being independent from primer libraries or PCR laboratory conditions, the probe sequences extracted by computer sequence data base search can also be synthesized as single stranded PNA-probes (Peptide Nucleic Acid probes). Gene targets can be specifically labelled with at least about 20 PNA-probes obtaining visibly background free specimens. By using appropriately designed triplex forming oligonucleotides, the denaturing procedures can completely be omitted. These results reveal a significant step towards oligonucleotide-FISH maintaining the 3d-nanostructure and even the viability of the cell target. The method is demonstrated with the detection of Her2/neu and GRB7 genes, which are indicators in breast cancer diagnosis and therapy.

  8. Big-fish-little-pond social comparison and local dominance effects : Integrating new statistical models, methodology, design, theory and substantive implications

    Marsh, Herbert W.; Kuyper, Hans; Morin, Alexandre J. S.; Philip, D. Parker; Seaton, Marjorie

    2014-01-01

    We offer new theoretical, substantive, statistical, design, and methodological insights into the seemingly paradoxical negative effects of school- and class-average achievement (ACH) on academic self-concept (ASC) the big-fish-little-pond-effect (BFLPE; 15,356 Dutch 9th grade students from 651 class

  9. Dissipation, Voltage Profile and Levy Dragon in a Special Ladder Network

    Ucak, C.

    2009-01-01

    A ladder network constructed by an elementary two-terminal network consisting of a parallel resistor-inductor block in series with a parallel resistor-capacitor block sometimes is said to have a non-dispersive dissipative response. This special ladder network is created iteratively by replacing the elementary two-terminal network in place of the…

  10. Bethe-Salpeter equation with cross-ladder kernel in Minkowski and Euclidean spaces

    Karmanov, V A; Mangin-Brinet, M

    2007-01-01

    Some results obtained by a new method for solving the Bethe-Salpeter equation are presented. The method is valid for any kernel given by irreducible Feynman graphs. The Bethe-Salpeter amplitude, both in Minkowski and in Euclidean spaces, and the binding energy for ladder + cross-ladder kernel are found. We calculate also the corresponding electromagnetic form factor.

  11. Emulating the Fast-Start Swimming Performance of the Chain Pickerel (Esox niger) Using a Mechanical Fish Design

    2006-09-01

    11 12 Chapter 1 Introduction The diversity of fish and marine mammal locomotion has long captured the...fins (Wakeling, 2001). Fish have evolved numerous methods of creating these forces over millions of years. Sorting the myriad of fish adaptations in...and locomotor behavior. Canadian Jouranal of Zoology, 59, 1072-1078. Schriefer, J. E. and Hale, M. E. (2004). Strikes and startles of northern

  12. Two experimental fish aggregating systems (fads in the Aegean sea: their design and application

    Aytaç Özgül

    2011-01-01

    Full Text Available Two steel spar buoys were constructed and moored in 50 and 100 m deep of water in the Aegean Sea to support recreational fisheries. The first FAD was deployed at coordinates 38°01´48´´N 26°58´02´´E and at a distance of 3 nautical miles from the shoreline. The other FAD was moored at 1.1 nautical miles from the shoreline at coordinates 38°03´11´´N; 26°59´01´´E. An anchor (1.2x1.2x0.8 m3 weighing approximate 2.76 metric ton, made of reinforced concrete, was used to hold a FAD weighing approximate 1.5 metric ton. Hardware and connections of FADs, ropes, mooring calculation and anchor design were made. The interaction between the forces of wave and current and FADs in those waters was investigated. In the experiment, all forces (drag force, buoyancy force etc. acting on FADs were calculated. It is proposed that the construction of the FADs should take the following design criteria into consideration: wave and current, forces related to the FADs, deployment depth, mooring hardware and ropes. This knowledge provides an important reference for stakeholders performing projects aiming to increase the performance and service life FADs.Duas bóias de aço spar foram construídas e ancoradas em 50 e 100 m de profundidade nas águas do Mar Egeu para dar apoio à pesca recreativa. O primeiro FAD foi implantado nas coordenadas 38°01'48''N 26°58'02''E, a uma distância de 3 milhas náuticas da costa. O outro ficou ancorado a 1,1 milha náutica da costa nas coordenadas 38°03'11''N; 26°59'01''E. Uma âncora (1.2x1.2x0.8 m3, pesando aproximadamente 2,76 toneladas, feita de concreto armado, foi usada para prender um FAD de peso aproximado de 1,5 toneladas. Foram realizados cálculos para determinação das conexões dos FADs, dos cabos e da ancoragem. A interação entre as forças de ondas e correntes com os FADs foi também investigada. No experimento, todas as forças (força de arrasto, força de empuxo, etc atuantes sobre os FADs foram

  13. 传统鱼图形在现代设计中的传承%Inheritance of Traditional Fish Graphics in Modern Design

    孔维艳

    2012-01-01

    传统鱼图形是中国传统艺术宝库中的有机分子。从设计应用角度解析了现代设计中传统鱼图形应用案例,根据对前人丰富的设计实践经验的总结和归纳将设计方法进行了整理,结合作者设计实践中民族图形元素使用规律,总结了传统鱼图形在现代设计中传承的具体方法。%Traditional fish graphics is one organic element in traditional Chinese art treasures. The application cases of traditional fish graphics in modem design have been analyzed from the perspective of application design, based on the induction of the predecessors' rich practical experience in design. Thus the inheritance methods of traditional fish graph- ics in modem design have been summarized combining the application law of national graphic elements in the design practice.

  14. Fish Allergy

    ... in a clear and consistent manner, so that consumers with food allergies and their caregivers can be informed as ... the menu, cross-contact with fish is possible. Ethnic ... fish. Avoid foods like fish sticks and anchovies. Some individuals with ...

  15. Fish Hearing.

    Blaxter, J. H. S.

    1980-01-01

    Provides related information about hearing in fish, including the sensory stimulus of sound in the underwater environment, mechanoreceptors in fish, pressure perception and the swimbladder, specializations in sound conduction peculiar to certain fish families. Includes numerous figures. (CS)

  16. F-ladder Knowledge and F-ladder Mining-discovery%F-阶梯知识与F-阶梯挖掘-发现

    郝秀梅; 李淑敏; 史开泉

    2012-01-01

    利用单向S-粗集(one direction singular rough sets)与它的动态特性,给出F-阶梯知识、F-阶梯度的概念.利用这些概念,提出F-阶梯知识分辩定理、最小F-阶梯知识挖掘-发现定理、最大F-阶梯知识挖掘-发现定理、知识发现依赖-筛选定理与F-阶梯知识内潜藏原理,给出F-阶梯知识挖掘-发现准则及应用.这些结果是单向S-粗集的新特性与单向S-粗集的动态特性的新应用.%By employing one direction S-rough sets (one direction singular rough sets) and its dynamic characteristic, this paper presented the concepts of F-ladder knowledge and F-ladder degree. Using theses concepts, the discernibility theorem of F-ladder knowledge, the mining-discovery theorem of minimum F-ladder knowledge, the mining-discovery theorem of maximum F-ladder knowledge and the dependence-filter theorem of knowledge discovery ere proposed,and the interior hiding principle of F-ladder knowledge, the mining-discovery criterion of F-ladder knowledge and its applications were given. The results given in this paper show the new characteristics of one direction S-rough sets and the new applications of the dynamic characteristic of one direction S-rough sets.

  17. Bound state structure and electromagnetic form factor beyond the ladder approximation

    Gigante, V; Ydrefors, E; Gutierrez, C; Karmanov, V A; Frederico, T

    2016-01-01

    We investigate the response of the bound state structure of a two-boson system, within a Yukawa model with a scalar boson exchange, to the inclusion of the cross-ladder contribution to the ladder kernel of the Bethe-Salpeter equation. The equation is solved by means of the Nakanishi integral representation and light-front projection. The valence light-front wave function and the elastic electromagnetic form factor beyond the impulse approximation, with the inclusion of the two-body current, generated by the cross-ladder kernel, are computed. The valence wave function and electromagnetic form factor, considering both ladder and ladder plus cross-ladder kernels, are studied in detail. Their asymptotic forms are found to be quite independent of the inclusion of the cross-ladder kernel, for a given binding energy. The asymptotic decrease of form factor agrees with the counting rules. This analysis can be generalized to fermionic systems, with a wide application in the study of the meson structure.

  18. Formation of a series of chimney-ladder compounds in the Ru-Re-Si system

    Simkin, B.A. [Department of Materials Science and Engineering, Kyoto University, Sakyo-ku, Kyoto 606-8501 (Japan); Ishida, A. [Department of Materials Science and Engineering, Kyoto University, Sakyo-ku, Kyoto 606-8501 (Japan); Okamoto, N.L. [Department of Materials Science and Engineering, Kyoto University, Sakyo-ku, Kyoto 606-8501 (Japan); Kishida, K. [Department of Materials Science and Engineering, Kyoto University, Sakyo-ku, Kyoto 606-8501 (Japan)]. E-mail: k.kishida@materials.mbox.media.kyoto-u.ac.jp; Tanaka, K. [Department of Materials Science and Engineering, Kyoto University, Sakyo-ku, Kyoto 606-8501 (Japan); Inui, H. [Department of Materials Science and Engineering, Kyoto University, Sakyo-ku, Kyoto 606-8501 (Japan)

    2006-06-15

    Rhenium-alloyed ruthenium sesquisilicide alloys have been prepared over the wide composition range Ru{sub 1-{delta}}Re {sub {delta}}Si{sub 1.5}, 0 {<=} {delta} {<=} 0.85. The phase relationships of these alloys have been investigated using X-ray powder diffraction, scanning electron microscopy and transmission electron microscopy. Alloys with {delta} {>=} 0.03 are multi-phase, composed of a series of (Ru,Re)Si {sub y} chimney-ladder phases with compositions of Ru{sub 1-x}Re {sub x}Si{sub 1.5386+0.1783x} (0.14 {<=} x {<=} 0.76) and B20-type monosilicide (Ru,Re)Si as a secondary phase. These chimney-ladder structures are considered to form to stabilize the high-temperature Ru{sub 2}Si{sub 3} chimney-ladder phase through the substitution of Ru with Re. The solubility limit of Re in a series of chimney-ladder phases is as large as 76% Re (x = 0.76) and the Si/(Ru + Re) ratio of the chimney-ladder phases increases with increasing Re content. The observed deviation of the chimney-ladder structure from the idealized composition and the possibility of adjusting the semiconducting properties of these chimney-ladder structures are discussed in terms of the valence electron concentration per metal atom.

  19. Phase sensitive quantum interference on forbidden transition in ladder scheme

    Koganov, Gennady A

    2014-01-01

    A three level ladder system is analyzed and the coherence of initially electric-dipole forbidden transition is calculated. Due to the presence of two laser fields the initially dipole forbidden transition becomes dynamically permitted due to ac Stark effect. It is shown that such transitions exhibit quantum-interference-related phenomena, such as electromagnetically induced transparency, gain without inversion and enhanced refractive index. Gain and dispersion characteristics of such transitions strongly depend upon the relative phase between the driving and the probe fields. Unlike allowed transitions, gain/absorption behavior of ac-Stark allowed transitions exhibit antisymmetric feature on the Rabi sidebands. It is found that absorption/gain spectra possess extremely narrow sub-natural resonances on these ac Stark allowed forbidden transitions. An interesting finding is simultaneous existence of gain and negative dispersion at Autler-Townes transition which may lead to both reduction of the group velocity a...

  20. SOLUTION PROPERTIES OF LADDER-LIKE POLYMER POLYPHENYLSILSESQUIOXANES

    SHI Lianghe; ZHANG Xinsheng; SI Yuandong; YE Meiling; LI Dingcai

    1987-01-01

    Solution properties of ladder-like polymer polyphenylsilsesquioxane (PPS) were studied by measurement of intrinsic viscosity, small angle laser light scattering and gel permeation chromatography. It was found that PPS can be modeled with a wormlike continuous cylinder rather than a wormlike coil. A plot of (M2/[η])1/3 vs. M1/2 was employed in obtaining the persistence length (2λ)-1 and effective hydrodynamic diameter. When MW≤5 × 105, Mark-Houwink equation is adequate in describing the relationship between MW and [η] with α about unity. This implies that PPS chain is semi-stiff. For GPC experiments, it was shown that universal calibration can be applied in PPS. When molecular weights of PPS are sufficiently high, their molecular weight distributions are often very broad.

  1. Ward Identity Constraints on Ladder Kernels in Transport Coefficient Calculations

    Gagnon, J.-S. [Department of Physics, McGill University, 3600 University Street, Montreal, H3A 2T8 (Canada); Jeon, S. [Department of Physics, McGill University, 3600 University Street, Montreal, H3A 2T8 (Canada)

    2007-03-15

    Using diagrammatic methods, we show how the Ward identity can be used to constrain the ladder kernel in transport coefficients calculations. More specifically, we use the Ward identity to determine the necessary diagrams that must be resummed (using the usual integral equation). Our main result is an equation relating the kernel of the integral equation with functional derivatives of the full (imaginary) self-energy; it is similar to what is obtained with 2PI effective action methods. However, since we use the Ward identity as our starting point, gauge invariance is preserved. Using power counting arguments, we also show which self-energies must be included in the resummation at leading order, including 2 to 2 scatterings and 1 to 2 collinear scatterings with the Landau-Pomeranchuk-Migdal (LPM) effect. In this study we restrict our discussion to electrical conductivity and shear viscosity in QED, but our method can in principles be generalized to other transport coefficients and other theories.

  2. Stark ladder in a one-dimensional quasiperiodic system

    Niizeki, K.; Matsumura, A.

    1993-08-01

    We have investigated the effect of a uniform field F on the energy spectrum of the Harper model, which includes an irrational ω and the phase variable cphi as parameters. The energy levels Ei(cphi), iEopenZ, are periodic on cphi, Ei(cphi+1)=Ei(cphi), and form a two-dimensional (2D) pattern in the cphi-E plane. The pattern which we term a 2D Wannier-Stark ladder (2DWSL) has 2D periodicity because of the equalities Ei(cphi)=iF+E0(cphi+iω), i∈openZ . The energy spectrum is a vertical section of the 2DWSL through the specified cphi and represents a quasiperiodic WSL.

  3. Polaron and bipolaron of uniaxially strained one dimensional zigzag ladder

    Yavidov, B.Ya., E-mail: bakhrom.yavidov@gmail.com

    2016-09-15

    An influence of the uniaxial strains in one dimensional zigzag ladder (1DZL) on the properties of polarons and bipolarons is considered. It is shown that strain changes all the parameters of the system, in particular, spectrum, existing bands and the masses of charge carriers. Numerical results obtained by taking into an account the Poisson effect clearly indicate that the properties of the (bi)polaronic system can be tuned via strain. Mass of bipolaron can be manipulated by the strain too which in turn leads to the way of tuning Bose–Einstein condensation temperature T{sub BEC} of bipolarons. It is shown that T{sub BEC} of bipolarons in strained 1DZL reasonably correlates with the values of critical temperature of superconductivity of certain perovskites.

  4. Quantum Walks of SU(2)_k Anyons on a Ladder

    Lehman, L; Brennen, G K

    2012-01-01

    We study the effects of braiding interactions on single anyon dynamics using a quantum walk model on a quasi-1-dimensional ladder filled with stationary anyons. The model includes loss of information of the coin and nonlocal fusion degrees of freedom on every second time step, such that the entanglement between the position states and the exponentially growing auxiliary degrees of freedom is lost. The computational complexity of numerical calculations reduces drastically from the fully coherent anyonic quantum walk model, allowing for relatively long simulations for anyons which are spin-1/2 irreps of SU(2)_k Chern-Simons theory. We find that for Abelian anyons, the walk retains the ballistic spreading velocity just like particles with trivial braiding statistics. For non-Abelian anyons, the numerical results indicate that the spreading velocity is linearly dependent on the number of time steps. By approximating the Kraus generators of the time evolution map by circulant matrices, it is shown that the spatial...

  5. A decision ladder analysis of eco-driving: the first step towards fuel-efficient driving behaviour.

    McIlroy, Rich C; Stanton, Neville A

    2015-01-01

    This paper provides a decision ladder analysis of eco-driving, and a discussion of the resultant models in terms of the skills, rules and knowledge taxonomy of human behaviour and how this can inform the design of an in-vehicle, eco-driving support system. In order to understand the types of behaviours that characterise fuel-efficient driving, a review was conducted of the academic literature and of more publicly available resources, such as governmental, car manufacturers' and specific eco-driving organisations' websites. The review identified four largely distinct driving activities that play a central role in the use of fuel in the private road vehicle. A focus group involving four researchers in the transport ergonomics field, followed by a series of five interviews with eco-driving experts, served to validate, supplement and further specify the models. Practitioner Summary: This paper presents a decision ladder analysis of eco-driving. A four-member focus group and five interviews with eco-driving experts were conducted; the resultant models are discussed in terms of supporting fuel-efficient driving behaviours in the novice eco-driver through their potential to inform the design of an in-vehicle eco-driving support system.

  6. Nested Bethe Ansatz for Spin Ladder Model with Open Boundary Conditions

    WU Jun-Fang; ZHANG Chun-Min; YUE Rui-Hong; LI Run-Ling

    2005-01-01

    The nested Bethe ansatz (BA) method is applied to find the eigenvalues and the eigenvectors of the transfer matrix for spin-ladder model with open boundary conditions. Based on the reflection equation, we find the general diagonal solution, which determines the generalboundary interaction in the Hamiltonian. We introduce the spin-ladder model with open boundary conditions. By finding the solution K± of the reflection equation which determines the nontrivial boundary terms in the Hamiltonian, we diagonalize the transfer matrix of the spin-ladder model with open boundary conditions in the framework of nested BA.

  7. Preparation and Characterization of Ordered Ladder Like Polyphenylsilsesquioxane via Two-step Sol-gel Method

    FENG Yu-zhong; QI Sheng-li; LIU Jing-jing; WU Zhan-peng; YANG Xiao-ping; JIN Ri-guang; WU De-zhen

    2011-01-01

    Soluble and ordered ladder like polyphenylsilsesquioxane was synthesized by a two-step sol-gel method including hydrolysis and polycondensation. The procedure was monitored by Fourier transform infrared spectroscopy and the presence of the ladder like structure was confirmed by X-ray techniques. 29Si NMR analysis shows a very narrow half peak width(δ<4) at δ-78.866 of the main chain unit C6H5SiO3/2 of polyphenylsilsesquioxane, indicating that the polyphenylsilsesquioxane has ordered ladder like structures rather than the branched ones. The relationship between molecular weight and the time of polycondensation was also discussed.

  8. Entanglement and Fidelity of a Spin Ladder with Dzyaloshinsky-Moriya Interaction

    陈雅; 朱士群

    2011-01-01

    The spin ladder with Dzyaloshinsky-Moriya interaction is investigated by using the quantum renormalization-group method. The entanglement and fidelity are periodic functions of the time and oscillate between zero and one. The oscillation period decreases with either the interaction in the spin ladder or the Dzyaloshinsky-Moriya interaction increasing. When the system relates to the environment, both entanglement and fidelity oscillate with a damping rate related to intrinsic decoherence rate, the interaction in the spin ladder, and the Dzyaloshinsky-Moriya interaction.

  9. Thermodynamics of the spin Luttinger liquid in a model ladder material.

    Rüegg, Ch; Kiefer, K; Thielemann, B; McMorrow, D F; Zapf, V; Normand, B; Zvonarev, M B; Bouillot, P; Kollath, C; Giamarchi, T; Capponi, S; Poilblanc, D; Biner, D; Krämer, K W

    2008-12-12

    The phase diagram in temperature and magnetic field of the metal-organic, two-leg, spin-ladder compound (C5H12N)2CuBr4 is studied by measurements of the specific heat and the magnetocaloric effect. We demonstrate the presence of an extended spin Luttinger-liquid phase between two field-induced quantum critical points and over a broad range of temperature. Based on an ideal spin-ladder Hamiltonian, comprehensive numerical modeling of the ladder specific heat yields excellent quantitative agreement with the experimental data across the entire phase diagram.

  10. Snakes and ladders: state interventions and the place of liberty in public health policy.

    Dawson, Angus J

    2016-08-01

    In this paper I outline and explore some problems in the way that the Nuffield Council of Bioethics' report Public Health: Ethical Issues (2007) presents its 'Intervention Ladder'. They see the metaphor of a ladder both as capturing key normative priorities and as making a real and important contribution to ethical policymaking in public health. In this paper I argue that the intervention ladder is not a useful model for thinking about policy decisions, that it is likely to produce poor decisions and that it is incompatible with the report's stated approach to relevant public health policy values.

  11. A General Study on Equivalent Resistance of Three-Terminal Ladder Network

    Wu Guoxiang; Tan Zhizhong; Song Guohua; Song Changqing

    2005-01-01

    In view of the application importance of resistance network in modern science and technology, the author presented the basic structure of a three-terminal ladder shaped resistance network and studied the equivalent resistance of the network. By means of virtual current method, the network was analyzed and a model of two elements three orders differential equation was constructed. Based on different marginal conditions, two general adaptive rules for the inlet resistance of the three-terminal ladder shaped network, as well as two ultimate rules for the equivalent resistance of three-terminal infinite ladder shaped network were given.

  12. CONCERTED H-BONDING TEMPLATE SYNTHESIS OF AN ORDERED LADDER POLYSILSESQUIOXANE

    Kui-lin Deng; Tao-yi Zhang; Xiao-jing Zhang; Ai-qin Zhang; Ping Xie; Rong-ben Zhang

    2006-01-01

    A novel soluble regular ladder poly(benzoyl-3-aminopropyl) silsesquioxane (LPBAS) was facilely prepared under effective assistance of concerted H-bonding self-assembly of amido groups of side chains and silanol groups, respectively, of a new template monomer [1,3-bis(benzoyl-3-aminopropyl)-1,1,3,3-tetraethoxydisiloxane] (M). The ordered ladder structure of LPBAS is manifested in: (1) the presence of two Bragg peaks representing the ladder width (d) and ladder thickness (t) in X-ray diffraction (XRD) pattern; (2) narrow base-line width (w = 6) of resonance absorption for -CH2SiO3/2 moiety in 29Si-NMR and (3) high glass transition temperature Tg = 112℃ in differential scanning calorimetry (DSC) analysis.

  13. Bethe-Salpeter equation in Minkowski space with cross-ladder kernel

    Karmanov, V A

    2006-01-01

    A new method for solving the Bethe-Salpeter equation is developed. It allows to find the Bethe-Salpeter amplitudes both in Minkowski and in Euclidean spaces and, as a by product, the light-front wave function. The method is valid for any kernel given by irreducible Feynman graphs. Bethe-Salpeter and Light-Front equations for scalar particles with ladder + cross-ladder kernel are solved.

  14. Photonic Bloch oscillations and Wannier-Stark ladders in exponentially chirped Bragg gratings.

    Wilkinson, P B

    2002-05-01

    The formation of photonic Bloch oscillations and Wannier-Stark ladders is demonstrated in an exponentially chirped one-dimensional Bragg grating. The photonic Bloch oscillations are investigated using Hamiltonian optics, and direct analogies are made with electron dynamics in periodic potentials. The results of transfer matrix calculations are presented, which show the existence of a photonic Wannier-Stark ladder that should be detectable in experiments.

  15. Pulse-Width Control in Ladder Structure Four-Phase Rectifier for AC-Electromotive

    Ivanov, V. V.; Myatez, S. V.; Langeman, E. G.; Schurov, N. I.

    2016-04-01

    Based on these studies the ways of power factor of the single-phase rectifiers operating in a single-phase AC network improving are suggested. The ladder four-phase rectifier is offered as a technical mean using a pulse-width method of controlling the rectified voltage. The pulse-width control efficiency as a way of the power factor rectifier with a ladder structure for AC electromotive improving is evaluated.

  16. The Plastic Surgery Compass: Navigating the Reconstructive Ladder in the Personalized Health Care Era.

    Sandberg, Lars Johan M

    2016-09-01

    The reconstructive ladder and the reconstructive elevator have withstood the test of time as didactic tools for resident education. Over time, many alternative models have been suggested to incorporate the technological advances in plastic surgery, but none of them have focused on the patient. Changes in practice and the trend toward personalized health care demand a 360-degree evaluation and solution of surgical problems incorporating patient-specific characteristics. We, therefore, suggest the concept of the plastic surgery compass to navigate the ladder.

  17. The cyclic cystine ladder in θ-defensins is important for structure and stability, but not antibacterial activity.

    Conibear, Anne C; Rosengren, K Johan; Daly, Norelle L; Henriques, Sónia Troeira; Craik, David J

    2013-04-12

    θ-Defensins are ribosomally synthesized cyclic peptides found in the leukocytes of some primate species and have promising applications as antimicrobial agents and scaffolds for peptide drugs. The cyclic cystine ladder motif, comprising a cyclic peptide backbone and three parallel disulfide bonds, is characteristic of θ-defensins. In this study, we explore the role of the cyclic peptide backbone and cystine ladder in the structure, stability, and activity of θ-defensins. θ-Defensin analogues with different numbers and combinations of disulfide bonds were synthesized and characterized in terms of their NMR solution structures, serum and thermal stabilities, and their antibacterial and membrane-binding activities. Whereas the structures and stabilities of the peptides were primarily dependent on the number and position of the disulfide bonds, their antibacterial and membrane-binding properties were dependent on the cyclic backbone. The results provide insights into the mechanism of action of θ-defensins and illustrate the potential of θ-defensin analogues as scaffolds for peptide drug design.

  18. Fish allergy and fish allergens

    Kuehn, A; Hilger, Christiane; Ollert, Markus

    2016-01-01

    Fish is one of the main elicitors for food allergies. For a long time, the clinical picture of fish allergy was reduced to the following features. First, fish-allergic patients suffer from a high IgE cross-reactivity among fishes so that they have to avoid all species. Second, clinically relevant...... review gives an overview on the clinical characteristics of fish allergy and the molecular properties of relevant fish allergens. The advancement of the IgE-based diagnosis using a panel of well-defined fish allergens from different species is in the focus of the discussion. © 2016 Dustri-Verlag Dr. Karl...

  19. Power Test of the Ladder IH-RFQ Accelerator at Peking University

    LU Yuan-Rong; CHEN Wei; NIE Yuan-Cun; LIU Ge; GAO Shu-Li; ZENG Hong-Jin; YAN Xue-Qing; CHEN Jia-Er

    2011-01-01

    A 104-MHz ladder interdigital-H radio frequency quadrupole accelerator (T-IH-RFQ) is developed for applying RFQs to heavy ion implantation and accelerator-based mass spectroscopy in recent years at the Institute of Heavy Ion Physics,Peking University.It could accelerate ions with a mass-to-charge ratio of less than 14,from 2.9 ke V/u to 35.7keV/u within a length of 1.1 m.The T-IH-RFQ cavity operating at H21(0) mode was constructed successfully.Based on a well designed rf power feeding system,the cavity was cold measured and tested with high rf power.In the case of cold measurement,the rf properties were obtained using a vector network analyzer with the help of a perturbation capacitor. During a high power test,the inter-electrode voltage was derived from the energy spectrum of x-rays measured by a high purity Ge detector.The results show that the specific shunt impedance of the T-IH-RFQ cavity reaches 178kΩm,which could meet the requirements of beam dynamics design.

  20. Computational flow simulation supporting the design of the Geesthacht fish pass; Numerische Modelluntersuchungen im Rahmen der Planung der Fischaufstiegsanlage Geesthacht

    Oberle, Peter; Musall, Mark; Riesterer, Jochen; Nestmann, Franz [Karlsruher Institut fuer Technologie (KIT), Karlsruhe (DE). Inst. fuer Wasser und Gewaesserentwicklung (IWG)

    2012-07-01

    In the year 2010 Europe's largest fish pass with basins at the Elbe-weir near Geesthacht was put into operation. Since then fish of many different kinds and sizes pass the building every day. The geometrical configuration of the facility, realized as a double slot pass, is based on extensive hydraulic model investigations. Thereby, apart from the flow characteristic within the building, also location-specific and operational aspects were to be analyzed and integrated into the planning concept. Due to the complex hydraulic boundary conditions as well as the high fish-ecological requirements a hybrid modeling approach with computational flow simulation in connection with physical model tests was employed, whereby substantial synergies as well as a good prognosis ability of the computer-aided simulation showed up. (orig.)

  1. Resonant Tunneling States of a Pairing Ladder with Random Dimer Chains

    HU Dong-Sheng; ZHANG Yan-Ling; YIN Xiao-Gang; ZHU Chen-Ping; ZHANG Yong-Mei

    2012-01-01

    We propose three models of pairing ladders, in which two types of atoms, A and B, exist, and the corresponding atoms in different chains are pairng, I.e. if atom A is in a site of one chain, the atom in the corresponding site of another chain should be atom B. It is found that there are three resonant states in the ladder when the two types of atoms are both random dimers (RD) in the same chain. No extended state exists in the ladder when only one type of atom is RD distributed or two types of atoms both are random distributed in the same chain.%We propose three models of pairing ladders,in which two types of atoms,A and B,exist,and the corresponding atoms in different chains are pairng,i.e.if atom A is in a site of one chain,the atom in the corresponding site of another chain should be atom B.It is found that there are three resonant states in the ladder when the two types of atoms are both random dimers (RD) in the same chain.No extended state exists in the ladder when only one type of atom is RD distributed or two types of atoms both are random distributed in the same chain.

  2. 梯形图可视化编辑与指令表的生成%Visual editing of PLC ladder diagram and generating of the instruct list

    李丹丹; 蔡启先; 于洋

    2012-01-01

    介绍了PLC梯形图可视化编辑与指令表生成系统的设计,针对二叉树结构算法的不足提出了一种新的将梯形图转化为指令表的优化算法.文中通过实例说明了将梯形图转换成逻辑树的扫描过程,给出了逻辑树的遍历方法以及实验结果.证明了该算法的可行性.%The design of a system that the visual editing of PLC ladder diagram and generating of instruct list is proposed, aiming at the limitation and lack of the algorithm of binary tree structure, a new algorithm to convert ladder diagram to instruction list is presented. Through an example describe the scanning process of ladder diagram convert to logic tree as well as traversal algorithm of logic tree, experimental result shows the feasibility of this algorithm.

  3. Study and designing of prepare handle machine with fish process of chain%链式淡水鱼加工前处理装置的研制

    彭三河; 徐武

    2013-01-01

    将剖切、去除内脏工艺结合在一起是鱼加工前期处理的关键问题,前处理不仅要求生产率高,还要保证处理后的品质好.从鱼结构特点及对其品质要求出发,设计链式鱼加工前处理装置,并简述其工艺流程、结构特点及主要设计参数.该装置采用链盒固鱼输送、圆盘刀剖切鱼腹、掏铲去内脏及清水冲洗联合处理工艺.试验证明该装置结构紧凑,处理能力20尾/min左右,操作安全,运行可靠,能够满足实际生产的要求.%To combinate the scaling technics, removing the internal organs technics and blacking membrane process technology is the key issue of fish processing pretreatment, pretreatment require not only high productivity, but also to ensure good quality after treatment. Starting from the structural characteristics of the fish and its quality requirements, I design a fish processing machine, and outline its pretreatment process, structural features and the main design parameters. The model adopt the gear and belt to transmit the fish, the brush to strip the scales , the dig shovel to remove the internal organs and a friction plate to black the membrane. Practice has shown the machine has many advantages ,for example higher integrated level, better processing quality and lower per unit mass cost.

  4. Deep Fish.

    Ishaq, Omer; Sadanandan, Sajith Kecheril; Wählby, Carolina

    2017-01-01

    Zebrafish ( Danio rerio) is an important vertebrate model organism in biomedical research, especially suitable for morphological screening due to its transparent body during early development. Deep learning has emerged as a dominant paradigm for data analysis and found a number of applications in computer vision and image analysis. Here we demonstrate the potential of a deep learning approach for accurate high-throughput classification of whole-body zebrafish deformations in multifish microwell plates. Deep learning uses the raw image data as an input, without the need of expert knowledge for feature design or optimization of the segmentation parameters. We trained the deep learning classifier on as few as 84 images (before data augmentation) and achieved a classification accuracy of 92.8% on an unseen test data set that is comparable to the previous state of the art (95%) based on user-specified segmentation and deformation metrics. Ablation studies by digitally removing whole fish or parts of the fish from the images revealed that the classifier learned discriminative features from the image foreground, and we observed that the deformations of the head region, rather than the visually apparent bent tail, were more important for good classification performance.

  5. Apollo 11 Astronaut Neil Armstrong Performs Ladder Practice

    1969-01-01

    In preparation of the nation's first Lunar landing mission, Apollo 11 crew members underwent training activities to practice activities they would be performing during the mission. In this photograph, Neil Armstrong, donned in his space suit, practices getting back to the first rung of the ladder on the Lunar Module (LM). The Apollo 11 mission launched from the Kennedy Space Center (KSC) in Florida via the Marshall Space Flight Center (MSFC) developed Saturn V launch vehicle on July 16, 1969 and safely returned to Earth on July 24, 1969. Aboard the space craft were astronauts Neil A. Armstrong, commander; Michael Collins, Command Module (CM) pilot; and Edwin E. (Buzz) Aldrin Jr., Lunar Module (LM) pilot. The CM, 'Columbia', piloted by Collins, remained in a parking orbit around the Moon while the LM, 'Eagle'', carrying astronauts Armstrong and Aldrin, landed on the Moon. On July 20, 1969, Armstrong was the first human to ever stand on the lunar surface, followed by Aldrin. During 2½ hours of surface exploration, the crew collected 47 pounds of lunar surface material for analysis back on Earth. With the success of Apollo 11, the national objective to land men on the Moon and return them safely to Earth had been accomplished.

  6. Ladder Operators for Lamé Spheroconal Harmonic Polynomials

    Ricardo Méndez-Fragoso

    2012-10-01

    Full Text Available Three sets of ladder operators in spheroconal coordinates and their respective actions on Lamé spheroconal harmonic polynomials are presented in this article. The polynomials are common eigenfunctions of the square of the angular momentum operator and of the asymmetry distribution Hamiltonian for the rotations of asymmetric molecules, in the body-fixed frame with principal axes. The first set of operators for Lamé polynomials of a given species and a fixed value of the square of the angular momentum raise and lower and lower and raise in complementary ways the quantum numbers $n_1$ and $n_2$ counting the respective nodal elliptical cones. The second set of operators consisting of the cartesian components $hat L_x$, $hat L_y$, $hat L_z$ of the angular momentum connect pairs of the four species of polynomials of a chosen kind and angular momentum. The third set of operators, the cartesian components $hat p_x$, $hat p_y$, $hat p_z$ of the linear momentum, connect pairs of the polynomials differing in one unit in their angular momentum and in their parities. Relationships among spheroconal harmonics at the levels of the three sets of operators are illustrated.

  7. Antarctic Fishes.

    Eastman, Joseph T.; DeVries, Arthur L.

    1986-01-01

    Explains the adaptations to Antarctic waters that Notothenioidei, a group of advanced bony fishes, have exhibited. Discusses the fishes' mechanisms of production of antifreeze properties and their capacities for neutral buoyancy in water. (ML)

  8. Theoretical study of anisotropic mobility in ladder-type molecule organic semiconductors

    Wei, Hui-Ling; Liu, Yu-Fang

    2014-09-01

    The properties of two ladder-type semiconductors {M1: 2,2'-(2,7-dihexy1-4,9-dihydro- s-indaceno[1,2- b:5,6- b']dithiophene-4,9-diylidene) dimalononitrile and M2: 2,7-dihexy1-4,9-dihydro- s-indaceno[1,2- b:5,6- b']dithiophene-4,9-dione} as the n-type and ambipolar organic materials are systematically investigated using the first-principle density functional theory combined with the Marcus-Hush electron transfer theory. It is found that the substitution of M1 induces large changes in its electron-transfer mobility of 1.370 cm2 V-1 s-1. M2 has both large electron- and hole-transfer mobility of 0.420 and 0.288 cm2 V-1 s-1, respectively, which indicates that M2 is potentially a high efficient ambipolar organic semiconducting material. Both the M1 and M2 crystals show remarkable anisotropic behavior. A proper design of the n-type and ambipolar organic electronic materials, which may have high mobility performance, is suggested based on the investigated two molecules.

  9. On the Consistency of the Ladder Approximation and the Rainbow Approximation of Dyson-Schwinger Equation of QCD

    Chang, L; Chang, Lei; Liu, Yu-xin

    2006-01-01

    We study the consistency of the ladder approximation and the rainbow approximation of the Dyson-Schwinger equation of QCD. By considering the non-Abelian property of QCD, we show that the QED-type Ward-Takahashi identity is not required for the rainbow-ladder approximation of QCD. It indicates that there does not exists any internal inconsistency in the usual rainbow-ladder approximation of QCD. In addition, we propose an modified ladder approximation which guarantees the Slavnov-Taylor identity for the quark-gluon vertex omitting the ghost effect in the approximation.

  10. Optical design of fish-eye lens used for monitoring system%用于监控系统的鱼眼镜头光学设计

    梁久伟; 罗春华; 杨铭

    2011-01-01

    The bionics principle is used based on the principle of fish-eye lens and monitor control system requirements. A fish-eye lens that FOV is 180° and relative aperture is 1/1. 6 is designed with the optical system design software ZEMAX to meet the requirement of the monitor control system on panoramic monitor. The designed system consists nine lenses. The total length is 68. 5mm, image receiver is 1/3 inch CCD, the MTF value is more than 0. 3 within 0. 7 FOV at 80lp/mm, the MTF value of FOV are more than 0. 5 within 0 FOV at 120lp/mm. The lens has high distortion because of this lens is a fish-eye lens. Its barrel distortion approximates to 100% within 1. 0 FOV.%为了满足监控系统中单镜头可实现全景监控的需求,运用仿生学原理,在原有鱼眼镜头的基础上结合监控系统的需求,运用ZEMAX软件设计了一款视场为180°,相对孔径为1/1.6的鱼眼镜头.该镜头由9片透镜组成,总长度为68.5mm,采用1/3英寸CCD作为图像接收器件.在120lp/mm时,其MTF曲线在轴上大于0.4,在80lp/mm时,在0.7带上大于0.3.由于是超广角镜头,此镜头畸变很大,在边缘视场具有接近100%的桶形畸变.

  11. Reproductive strategies and seasonal changes in the somatic indices of seven small-bodied fishes in Atlantic Canada in relation to study design for environmental effects monitoring.

    Barrett, Timothy J; Brasfield, Sandra M; Carroll, Leslie C; Doyle, Meghan A; van den Heuvel, Michael R; Munkittrick, Kelly R

    2015-05-01

    Small-bodied fishes are more commonly being used in environmental effects monitoring (EEM) studies. There is a lack of understanding of the biological characteristics of many small-bodied species, which hinders study designs for monitoring studies. For example, 72% of fish population surveys in Canada's EEM program for pulp and paper mills that used small-bodied fishes were conducted outside of the reproductive period of the species. This resulted in an inadequate assessment of the EEM program's primary effect endpoint (reproduction) for these studies. The present study examined seasonal changes in liver size, gonad size, and condition in seven freshwater and estuarine small-bodied fishes in Atlantic Canada. These data were used to examine differences in reproductive strategies and patterns of energy storage among species. Female gonadal recrudescence in all seven species began primarily in the 2-month period in the spring before spawning. Male gonadal development was concurrent with females in five species; however, gonadal recrudescence began in the fall in male three-spined stickleback (Gasterosteus aculeatus) and slimy sculpin (Cottus cognatus). The spawning period for each species was estimated from the decline in relative ovary size after its seasonal maximum value in spring. The duration of the spawning period reflected the reproductive strategy (single vs multiple spawning) of the species. Optimal sampling periods to assess reproductive impacts in each species were determined based on seasonal changes in ovary size and were identified to be during the prespawning period when gonads are developing and variability in relative gonad size is at a minimum.

  12. Biomechanical analysis of loading/unloading a ladder on a truck.

    Moriguchi, Cristiane Shinohara; Carnaz, Leticia; de Miranda, Luiz Carlos; Marklin, Richard William; Coury, Helenice Jane Cote Gil

    2012-01-01

    Loading/unloading a ladder on vehicles are frequent tasks and involve overhead handling that may expose workers to risk factors of shoulder musculoskeletal disorders. The objective of the present study was to evaluate posture, forces required and perceived exertion when loading and unloading the ladder on a utility truck. Thirteen male overhead line workers from an electric utility in Brazil participated in this study. Shoulder elevation angle was measured using inclinometers. The required force to load/unload the ladder was measured by dynamometer. Subjective assessment of the perceived exertion was recorded to compare the exertion reported during the test conditions to the field conditions. The task of loading/unloading the ladder presented risks of shoulder musculoskeletal disorders (MSDs) to workers because it requires high levels of force (approximately 60% of the maximal force) combined with overhead posture of the shoulders (more than 100° from the neutral posture). Age and height presented to interfere in biomechanical risks presented in load/unload task. There was no significant difference between the subjective exertion during the test conditions and handling the ladder in the field. Ergonomic intervention is recommended to reduce these risks for shoulder MSDs.

  13. Doped spin ladders under magnetic field; Echelles de spins dopees sous champ magnetique

    Roux, G

    2007-07-15

    This thesis deals with the physics of doped two-leg ladders which are a quasi one-dimensional and unconventional superconductor. We particularly focus on the properties under magnetic field. Models for strongly correlated electrons on ladders are studied using exact diagonalization and density-matrix renormalization group (DMRG). Results are also enlightened by using the bosonization technique. Taking into account a ring exchange it highlights the relation between the pairing of holes and the spin gap. Its influence on the dynamics of the magnetic fluctuations is also tackled. Afterwards, these excitations are probed by the magnetic field by coupling it to the spin degree of freedom of the electrons through Zeeman effect. We show the existence of doping-dependent magnetization plateaus and also the presence of an inhomogeneous superconducting phase (FFLO phase) associated with an exceeding of the Pauli limit. When a flux passes through the ladder, the magnetic field couples to the charge degree of freedom of the electrons via orbital effect. The diamagnetic response of the doped ladder probes the commensurate phases of the t-J model at low J/t. Algebraic transverse current fluctuations are also found once the field is turned on. Lastly, we report numerical evidences of a molecular superfluid phase in the 3/2-spin attractive Hubbard model: at a density low enough, bound states of four fermions, called quartets, acquire dominant superfluid fluctuations. The observed competition between the superfluid and density fluctuations is connected to the physics of doped ladders. (author)

  14. Hood River Pelton Ladder Studies : Annual Report 1995.

    Olsen, Erik A.; French, Rod A.; Ritchey, Alan D.

    1996-09-01

    Data collected from this program will provide the baseline information needed to (1) evaluate various management options for implementing the Hood River Production Plan and (2) determine any post-project impacts the Hood River Production Plan has on indigenous populations of resident fish.

  15. Dynamic Covalent Assembly of Peptoid-Based Ladder Oligomers by Vernier Templating.

    Wei, Tao; Jung, Jae Hwan; Scott, Timothy F

    2015-12-30

    Dynamic covalent chemistry, in conjunction with template-directed assembly, enables the fabrication of extended nanostructures that are both precise and tough. Here we demonstrate the dynamic covalent assembly of peptoid-based molecular ladders with up to 12 rungs via scandium(III)-catalyzed imine metathesis by employing the principle of Vernier templating, where small precursor units with mismatched numbers of complementary functional groups are coreacted to yield larger structures with sizes determined by the respective precursor functionalities. Owing to their monomer diversity and synthetic accessibility, sequence-specific oligopeptoids bearing dynamic covalent pendant groups were employed as precursors for molecular ladder fabrication. The generated structures were characterized using matrix-assisted laser desorption/ionization mass spectrometry and gel permeation chromatography, confirming successful molecular ladder fabrication.

  16. Climbing a ladder: a step-by-step approach to understanding the concept of agroecosystem health.

    Alkorta, I; Albizu, I; Amezaga, I; Onaindia, M; Buchner, V; Garbisu, C

    2004-01-01

    Population and individual health is linked to agroecosystem health. To comprehend the concept of agroecosystem health, one should climb a ladder consisting of several successive steps, each rung presenting a certain degree of instability (conceptual difficulty and uncertainty) in an advisable but not inevitable order. Here we suggest a ladder consisting of the following concepts: ecosystem, agroecosystem, biodiversity, sustainability, ecosystem health, and agroecosystem health. Although these concepts are to a certain extent well understood and grasped by scientists, politicians, natural resource managers, and environmentalists, some steps are still highly debatable, unclear, and present a considerable degree of reluctance to be defined and understood. Consequently, much empirical and theoretical effort must be made to construct solid conceptual ladders made up of such steps. In this enterprise, a traditional reductionistic approach confining interpretations to narrow scientific disciplines is unadvisable. Holistic, transdisciplinary approaches are required to reach the desired goal.

  17. Statistical Transfer Matrix Study of the ± J Multileg Ising Ladders and Tubes

    Hida, Kazuo

    2012-07-01

    Finite temperature properties of symmetric ± J multileg Ising ladders and tubes are investigated using the statistical transfer matrix method. The temperature dependences of the specific heat and entropy are calculated. In the case of tubes, it is found that the ground-state entropy shows an even--odd oscillation with respect to the number of legs. The same type of oscillation is also found in the ground-state energy. On the contrary, these oscillations do not take place in ladders. From the temperature dependence of the specific heat, it is found that the lowest excitation energy is 4J for even-leg ladders while it is 2J otherwise. The physical origin of these behaviors is discussed based on the structure of excitations.

  18. Effect of blank holder pressure on viscous pressure forming aluminum alloy ladder parts

    王忠金; 王新云; 王仲仁

    2002-01-01

    Viscous pressure forming (VPF), is suitable for forming difficult-to-form sheet metal parts. An investigation in the effect of blank holder pressure (BHP) on VPF aluminum alloy ladder parts was conducted. Based on experimental and numerical simulation results of the effect of BHP on dimensional accuracy, wall-thickness reduction, forming pressure, material flow and defects (such as wrinkling and fracture) of specimens, the effect patterns of BHP load path on VPF ladder parts were explained. The limits of BHP corresponding to specimens with no defect and with wrinkling or fracture defect were determined. In the limits of formable BHP, the variable load path of BHP was beneficial to drawing blank into the die and decreasing wall-thickness reduction of specimens. The experimental results show that the ladder parts of good surface fineness and high dimensional accuracy can be obtained by variable load paths of BHP.

  19. Nestling diets and provisioning rates of sympatric Golden-fronted and Ladder-backed Woodpeckers

    Schroeder, Evonne L.; Boal, Clint W.; Glasscock, Selma N.

    2013-01-01

    We examined comparative food use and provisioning of Golden-fronted (Melanerpes aurifrons) and Ladder-backed (Picoides scalaris) woodpeckers at the Rob and Bessie Welder Wildlife Foundation Refuge, in San Patricio County, Texas. We combined video surveillance and direct observations to monitor provisioning rates and identify items delivered by adult woodpeckers to nestlings. We collected 328 hours of data at Ladder-backed Woodpecker nest cavities and 230 hours of data at Golden-fronted Woodpecker nest cavities. Ladder-backed Woodpecker nestling diets consisted of 100% animal matter, comprised of invertebrate larvae (99%) and invertebrate adults (nestlings were also high in animal matter (77%) with more invertebrate adults (55%) and fewer invertebrate larvae (27%), but also included vegetable matter (16%). Morisita's measure of overlap suggested a relatively low dietary overlap of 31% between nestlings of these two sympatric woodpecker species. Foraging methods used by these species may explain their low dietary overlap and facilitate their coexistence.

  20. Flux-driven quantum phase transitions in two-leg Kitaev ladder topological superconductor systems

    Wang, H. Q.; Shao, L. B.; Pan, Y. M.; Shen, R.; Sheng, L.; Xing, D. Y.

    2016-12-01

    We investigate a two-leg ladder topological superconductor system consisting of two parallel Kitaev chains with interchain coupling. It is found that either uniform or staggered fluxes threading through the ladder holes may change the ladder system from the BDI class in the Altland-Zirnbauer (AZ) classification to the D class. After explicitly calculating the topological Z and/or Z2 indices and from the evolution of Majorana zero energy states (MZES), we obtain the flux-dependent phase diagrams, and find that quantum phase transitions between topologically distinct phases characterized by different number of MZES may happen by simply tuning the flux, which could be realized experimentally in ultracold systems.

  1. BIOTECHNOLOGY OF THE FISH AQUACULTURE

    L. P. Buchatsky

    2013-12-01

    Full Text Available The latest progress in biotechnology on fish aquaculture and different modern methods of investigations for increasing of fish productivity in aquaculture are analyzed. Except for the applied aspect, the use of modern biotechnological methods of investigations opens new possibilities for fundamental researches of sex-determining mechanisms, polyploidy, distant hybridization, and developmental biology of bony fishes. Review contains examples of utilizing modern biotechnology methods to obtain transgenic fishes with accelerated growth and for designing surrogate fishes. Methods for receiving unisexual shoals of salmon and sturgeon female fishes with the view of obtaining a large quantity of caviar, as well as receiving sterile (triploid fishes are analyzed. Great attention is given to androgenesis, particularly to disperm one, in connection with the problem of conserving rare and vanishing fish species using only sperm genetic material. Examples how distant hybrids may be obtained with the use of disperm androgenesis and alkylated DNA are given. Methods of obtaining fish primordium germ cells, recent developments in cultivation of fish stem cells and their use in biotechnology, as well as ones of transplantation of oogonium and spermatogonium to obtain surrogate fishes. The examples of successful experiments on spermatogonial xenotransplantation and characteristic of antifreezing fish proteins and also the prospect of their practical usage are given.

  2. 数控系统中PLC梯形图与指令表的转换算法%Algorithm on Transforming PLC Ladder Diagram to Instruction Table in NC System

    罗海据; 吴永明; 梁娟

    2014-01-01

    In order to meet requirements of transforming the ladder diagram programmable logic controller (PLC)into an instruc-tion table for numerical control (NC)system in machine tool,the PLC ladder diagram was divided into some structural components in-cluding base-line,ring,semi-ring and ring-base-line,and etc.By using these components,the validity of PLC ladder diagram was checked,the relationship between PLC ladder diagram and instruction table was analyzed,and the algorithm about transformation from PLC ladder diagram to instruction table was designed.The application examples show that the algorithm is efficient and has good real-time,which is suitable for the NC system of machine tool.%为了满足数控机床系统中PLC梯形图向指令表转换的要求,将梯形图的构成形式分成母线、环、半环、环母线等结构元素,利用这些结构元素检验梯形图的合法性,分析梯形图和指令表之间的关系,设计梯形图向指令表快速转换的算法。应用实例表明:该算法效率高,实时性好,能满足数控机床系统的要求。

  3. Number of embeddings of circular and Mbius ladders on surfaces

    2010-01-01

    There are many results on the flexibility of(general) embeddings of graphs,but few are known about that of strong embeddings.In this paper,we study the flexibility of strong embeddings of circular and Mbius ladders on the projective plane and the Klein bottle by using the joint tree model of embeddings.The numbers of(nonequivalent) general embeddings and strong embeddings of circular and Mbius ladders on these two nonorientable surfaces are obtained,respectively.And the structures of those strong embeddings are described.

  4. The Plastic Surgery Compass: Navigating the Reconstructive Ladder in the Personalized Health Care Era

    2016-01-01

    Summary: The reconstructive ladder and the reconstructive elevator have withstood the test of time as didactic tools for resident education. Over time, many alternative models have been suggested to incorporate the technological advances in plastic surgery, but none of them have focused on the patient. Changes in practice and the trend toward personalized health care demand a 360-degree evaluation and solution of surgical problems incorporating patient-specific characteristics. We, therefore, suggest the concept of the plastic surgery compass to navigate the ladder. PMID:27757348

  5. Magnetic Long-Range Order and Colossal Magnetoresistance Effect in Double Exchange Ladders

    马冬梅; 邹良剑

    2001-01-01

    By applying Bogoliubov's ineguality to double-exchange(DE) ladders, we show that the ferromagnetic(FM) order is absent in the new DE systems at finite temperatures. The incorporation of Jahn-Teller electron-phonon coupling, orbital degeneracy and on-site Coulomb interaction with the DE interaction do not preserve these orders. The long-wavelength thermal fluctuations of the spins oversome the DEFM correlation and destroy the FM orders. The implication of the absence of FM order on the transport of the DE ladders is discussed.

  6. Numerical Study of Luttinger Liquid Regime of Two-Leg Hubbard Ladders

    CHENG Kuan; LIU Yu-Liang

    2005-01-01

    @@ We investigate two-leg Hubbard ladders in the Luttinger liquid regime by the density-matrix renormalization group method. Applicability of the bond concept in this region is discussed in a quantitative comparison of power-law decay exponents, energy components and anti-bond occupations between ladders and chains. The interaction between bond and anti-bond bands induced by finite Hubbard repulsion U is emphasized by our numerical results. Our quantitative results are useful for the justification of the validity of various analytical approaches.

  7. Climb the Green Ladder Make Your Company and Career More Sustainable

    Fetzer, Amy V

    2009-01-01

    Want to make your workplace more sustainable, get ahead in your career and improve your reputation?. Want to help your company or organisation save money, boost profits and improve its brand?. Whatever your level or industry, from sales and management to government and teaching, Climb The Green Ladder offers practical knowledge to help you make a difference. Whether you'd like to transform your entire company or just get your colleagues recycling, Climb The Green Ladder will provide you with the tools and motivation to move your company (and career) towards a more successful, more sustainable

  8. Explaining choice option attractiveness by beliefs elicited by the laddering method

    Grunert, Klaus G.; Bech-Larsen, Tino

    2005-01-01

    option. The laddering method is used to elicit beliefs of all three types for a choice between conventional and organic pork. As a benchmark, beliefs were also elicited in the traditional way advocated by Ajzen and Fishbein. Using both sets of beliefs in a subsequent survey, it was shown that the beliefs...... elicited by the laddering method increase explanatory power with regard to choice option attractiveness beyond the beliefs elicited by the Ajzen and Fishbein method, and that this additional explanatory power was due to those beliefs which relate the choice option to concepts with a higher level...

  9. 基于生态修复的青海湖沙柳河鱼道建设与维护%Construction and management of fish passage on Shaliu River adjacent to Qinghai Lake based on ecological restoration

    吴晓春; 史建全

    2014-01-01

    为减少水坝对青海湖裸鲤溯河洄游的阻隔,在入湖的沙柳河上先后建设了导壁式、简易模块式和阶梯型鱼道。通过对青海湖鱼道建设案例分析,得出鱼道设计需要关注的问题:鱼道进鱼口设计要安排在鱼类洄游通路并采取集鱼措施,鱼道设计要依据鱼类洄游能力,鱼道运行要注意改进和维护,鱼道设计需要多学科专家共同参与。结合国内外鱼道设计、建设和运行情况,提出基于生态修复的鱼道建设维护对策:确立生态系统功能价值的鱼道设计目标,确立从鱼的角度出发,系统性的鱼道设计理念、建设和管护方式。%Gymnocypris przewalskii belongs to subfamily of Schizothoracinae, family of Cyprinidae and order of Cypriniformes, and it is an endemic species only distributed in the Qinghai Lake and its adjacent rivers and lakes. It possesses migration characteristics, and goes upstream from the lake to surrounding rivers in the reproduction season. However, several dams built on the rivers flowing into the lake with the agricultural development in the Qinghai Lake region since 1970s, severely blocked its migration passages, leading to obviously decreasing of resources of Gymnocypris przewalskii in recent years. To protect Gymnocypris przewalskii, three kinds of fish passages on the dams of rivers flowing into the Qinghai Lake were introduced, which were types of guide wall, simple steel modular and ladder slope, respectively. 1) The guide wall type fish passage was separately constructed on the dams in the Shaliu River, Quanji River and Haergai River in 2006, which were built along river side, but it had several defects because of the lack of experience. 2) The simple steel modular type fish passage was designed and constructed on the dam of the Shaliu River in 2008, Based on biological characteristics of Gymnocypris przewalskii and the basic situation of the dam and environmental conditions of the Shaliu

  10. Fish health and fish quality

    Ingerslev, Hans-Christian

    Aquaculture is an expanding worldwide industry producing an increasing amount of fish every year. The quality of the fish meat is dependent upon many biological and non-biological factors. Infectious diseases are known to cause bleedings and damage of the muscle tissue that may lead to scarring...... are poorly described in fish. The present work in this thesis focused on: 1) examination of potential changes in the quality regarding texture of the muscle tissue in rainbow trout (Oncorhynchus mykiss) after previous infection with the bacterial pathogens Yersinia ruckeri and Vibrio anguillarum; 2...... of these studies showed that previous infections by Yersinia ruckeri and Vibrio anguillarum gave rise to subsequent changes regarding textural quality parameters in fresh fish meat, while no differences were seen for cold-smoked meat from the same fish. The texture in previous infected fish was less flaky and less...

  11. Computer-aided vaccine designing approach against fish pathogens Edwardsiella tarda and Flavobacterium columnare using bioinformatics softwares

    Mahendran R

    2016-05-01

    Full Text Available Radha Mahendran,1 Suganya Jeyabaskar,1 Gayathri Sitharaman,1 Rajamani Dinakaran Michael,2 Agnal Vincent Paul1 1Department of Bioinformatics, 2Centre for Fish Immunology, School of Life Sciences, Vels University, Pallavaram, Chennai, Tamil Nadu, India Abstract: Edwardsiella tarda and Flavobacterium columnare are two important intracellular pathogenic bacteria that cause the infectious diseases edwardsiellosis and columnaris in wild and cultured fish. Prediction of major histocompatibility complex (MHC binding is an important issue in T-cell epitope prediction. In a healthy immune system, the T-cells must recognize epitopes and induce the immune response. In this study, T-cell epitopes were predicted by using in silico immunoinformatics approach with the help of bioinformatics tools that are less expensive and are not time consuming. Such identification of binding interaction between peptides and MHC alleles aids in the discovery of new peptide vaccines. We have reported the potential peptides chosen from the outer membrane proteins (OMPs of E. tarda and F. columnare, which interact well with MHC class I alleles. OMPs from E. tarda and F. columnare were selected and analyzed based on their antigenic and immunogenic properties. The OMPs of the genes TolC and FCOL_04620, respectively, from E. tarda and F. columnare were taken for study. Finally, two epitopes from the OMP of E. tarda exhibited excellent protein–peptide interaction when docked with MHC class I alleles. Five epitopes from the OMP of F. columnare had good protein–peptide interaction when docked with MHC class I alleles. Further in vitro studies can aid in the development of potential peptide vaccines using the predicted peptides. Keywords: E. tarda, F. columnare, edwardsiellosis, columnaris, T-cell epitopes, MHC class I, peptide vaccine, outer membrane proteins 

  12. Fish parasites

    This book contains 22 chapters on some of the most important parasitic diseases in wild and farmed fish. International experts give updated reviews and provide solutions to the problems......This book contains 22 chapters on some of the most important parasitic diseases in wild and farmed fish. International experts give updated reviews and provide solutions to the problems...

  13. Gap Caused by Strong Pairing in the Ladder Model of DNA Molecules

    HU Dong-Sheng; ZHU Chen-Ping; ZHANG Long-Qiang; HE Da-Ren; WANG Bing-Hong

    2008-01-01

    By directly diagonalizing the Hamiltonian of the ladder model of deoxyribonucleic acid (DNA) molecules,the density of statcs is obtained.It is found that DNA behaves as a conductor when the interchain hopping is smaller than twice the intrachain one,otherwise,DNA behaves as a semiconductor.

  14. A Demonstration of Helping Adolescents with Mild Intellectual Disability Climb Ladders

    Chan, Kok Hoe Anthony; Varahan, Jayashree Lakshmi; Loh, Peng Loong Daniel; Tan, Sey Ing

    2011-01-01

    A research team at a vocational school in Singapore, catering mainly to students between the ages of 17-21 with mild intellectual disability, studied how to best address the challenge of enabling students to learn how to climb ladders (a skill necessary at many job placements). They documented the approach used and suggested extrapolations and…

  15. The physiological effect of a 'climb assist' device on vertical ladder climbing.

    Barron, Peter James; Burgess, Katherine; Cooper, Kay; Stewart, Arthur D

    2016-10-15

    'Climb assist' claims to reduce strain when climbing ladders; however, no research has yet substantiated this. The purpose of this study was to assess the physiological and psychophysical effects of climb assist on 30 m ladder climbing at a minimum acceptable speed. Eight participants (six male and two female) climbed a 30 m ladder at 24 rungs per minute with and without climb assist, and were monitored for heart rate (HR), [Formula: see text]O2 and rate of perceived exertion (RPE). All three variables decreased significantly (p climb assist with [Formula: see text]O2 decreasing by 22.5%, HR by 14.8% and RPE decreasing by a mean of 2.3 units on the 10-point Borg scale. When descending the ladder [Formula: see text]O2 decreased by a mean of 42% compared to that ascending. At the minimal acceptable climbing speed climb assist decreases the physiological strain on climbers, as demonstrated by reduced [Formula: see text]O2, HR and perceived exertion. Practitioner Summary: 'Climb assist' systems claim to reduce strain when climbing, however; no research has yet been published to substantiate this. A crossover study compared [Formula: see text]O2, HR and RPE at a minimal acceptable climbing speed with and without climb assist. Climb assist significantly reduced all variables confirming it reduces strain when climbing.

  16. Measuring subjective meaning structures by the laddering method: Theoretical considerations and methodological problems

    Grunert, Klaus G.; Grunert, Suzanne C.

    1995-01-01

    Starting from a general model of measuring cognitive structures for predicting consumer behaviour, we discuss laddering as a possible method to obtain estimates of consumption-relevant cognitive structures which will have predictive validity. Four criteria for valid measurement are derived...

  17. Avionics Instrument Systems Specialist Career Ladder: AFSCs 32531, 32551, 31571, and 32591. Occupational Survey Report.

    Air Force Occupational Measurement Center, Lackland AFB, TX.

    The Avionics Instrument Systems career ladder (AFSC 325X1) provides flight line and shop maintenance training on aircraft instrument systems, electromechancial instruments, components, and test equipment. Duties involve inspecting, removing, installing, repairing, operating, troubleshooting, overhauling, and modifying systems such as flight and…

  18. Expressions of excited states by triplet dimers in heisenberg antiferromagnetic ladders. Analysis of magnetic Raman spectra

    Natsume, Yuhei; Tada, Shinichiro; Suzuki, Toshihiko [Chiba Univ., Graduate School of Science and Technology, Chiba (Japan)

    2002-06-01

    Characteristic properties of excited states in antiferromagnetic ladder systems with spin-1/2 are investigated in relation with the theoretical analysis of the quite asymmetric shape of the peak for twice the spin gap {delta}{sub g} in magnetic Raman spectra. Here, the structure of exchange-scattering spectra are reproduced by the numerical calculation for the finite Heisenberg ladder, in which legs with antiferromagnetic bond J{sub c} is connected by rungs with antiferromagnetic bond J{sub r}. The singlet ground state in this system can be expressed as the ordering of singlet dimers on rungs in the ladder for J{sub c}/J{sub r} {yields} +0. In fact, the value of 0.1 is adopted to be the ratio of J{sub c}/J{sub r} in order to discuss the experimental work of the magnetic Raman spectra for the ladder of V{sup 4+} ions in the oxide compound CaV{sub 2}O{sub 5} reported in Konstantinovic et al., Phys. Rev. B61 (2000), 15185. As for this peak of 2{delta}{sub g}, quite an asymmetric observed shape is explained by the present calculation. According to the analysis of spectra, we discuss the expression of excited states by triplet dimers on rungs: The dominant contribution of the pair of triplet dimers on adjacent rungs to the corresponding state for 2{delta}{sub g} peak is pointed out. (author)

  19. On the Orchard crossing number of prisms, ladders and other related graphs

    Feder, Elie

    2011-01-01

    This paper deals with the Orchard crossing number of some families of graphs which are based on cycles. These include disjoint cycles, cycles which share a vertex and cycles which share an edge. Specifically, we focus on the prism and ladder graphs.

  20. Entrepreneurial Progress: Climbing The Entrepreneurial Ladder in Europe and The US

    P.W. van der Zwan (Peter); I. Verheul (Ingrid); A.R. Thurik (Roy); I. Grilo (Isabel)

    2009-01-01

    textabstractWe investigate which countries have the highest potential to achieve entrepreneurial progress. This progress is defined using an entrepreneurial ladder with five successive steps: “never thought about starting a business”, “thinking about starting a business”, “taking steps to start a bu

  1. Commutation-relation-preserving ladder operators for propagating optical fields in nonuniform lossy media

    Partanen, Mikko; Häyrynen, Teppo; Tulkki, Jukka;

    2015-01-01

    We have recently developed a quantized fluctuational electrodynamics (QFED) formalism to describe the quantum aspects of local thermal balance formation and to formulate the electromagnetic field ladder operators so that they no longer exhibit the anomalies reported for resonant structures. Here we...

  2. Design of Heat Pipe Type Adsorption Ice Maker for Fishing Boats%热管型船用吸附制冰机的设计

    王丽伟; 王如竹; 夏再忠; 吴静怡

    2005-01-01

    A heat pipe type adsorption ice maker with two adsorbers for fishing boats is designed by using ammonia as refrigerant and compound of activated carbon-CaCl2 as adsorbent. This type of heat pipe adsorber can solve the problem of incompatibility between ammonia, copper, seawater and steel. The working process of the ice maker with 8.7kg adsorbent per bed is simulated. The results show that the optimal semi-cycle time is about 9min at the evaporating temperature of -15℃, where the corresponding cooling power, specific cooling power per kilogram adsorbent SCP and coefficient of refrigerant performance COP are respectively 3.6 kW, 217W·kg-1 and 0.404.

  3. One Fish, Two Fish, Redfish, You Fish!

    White, Katherine; Timmons, Maryellen; Medders, Paul

    2011-01-01

    The recreational fishing activity presented in this article provides a hands-on, problem-based experience for students; it unites biology, math, economics, environmental policy, and population dynamics concepts. In addition, the activity allows students to shape environmental policy in a realistic setting and evaluate their peers' work. By…

  4. 50 CFR 14.23 - Live farm-raised fish and farm-raised fish eggs.

    2010-10-01

    ... 50 Wildlife and Fisheries 1 2010-10-01 2010-10-01 false Live farm-raised fish and farm-raised fish eggs. 14.23 Section 14.23 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF... Exportation at Designated Ports § 14.23 Live farm-raised fish and farm-raised fish eggs. Live farm-raised...

  5. Fighting fish

    Duchi, E.; Guerrini, V.; Rinaldi, S.; Schaeffer, G.

    2017-01-01

    We introduce new combinatorial structures, called fighting fish, that generalize directed convex polyominoes by allowing them to branch out of the plane into independent substructures. On the one hand the combinatorial structure of fighting fish appears to be particularly rich: we show that their generating function with respect to the perimeter and number of tails is algebraic, and we conjecture a mysterious multivariate equidistribution property with the left ternary trees introduced by Del Lungo et al On the other hand, fighting fish provide a simple and natural model of random branching surfaces which displays original features: in particular, we show that the average area of a uniform random fighting fish with perimeter 2n is of order n 5/4: to the best of our knowledge this behaviour is non-standard and suggests that we have identified a new universality class of random structures. Dedicated to Tony Guttmann on the occasion of his 70th birthday.

  6. Mathematical model analysis on the enhancement of aeration efficiency using ladder-type flat membrane module forms in the Submerged Membrane Bio-reactor(SMBR)

    2009-01-01

    The cross-flow shearing action produced from the inferior aeration in the Submerged Membrane Bio-reactor(SMBR) is an effective way to further improve anti-fouling effects of membrane modules.Based on the widely-applied vertical structure of flat membrane modules,improvements are made that ladder-type flat membrane structure is designed with a certain inclined angle θ so that the cross-flow velocity of bubble near the membrane surface can be held,and the intensity and times of elastic colli-sion between bubbles and membrane surface can be increased.This can improve scouring action of membrane surface on aeration and reduce energy consumption of strong aeration in SMBR.By de-ducing and improving the mathematics model of collision between bubble and vertical flat put forward by Vries,the relatively suitable incline angle θ under certain aeration place and in certain size rang of bubble can be obtained with the computer iterative calculation technology.Finally,for many groups of ladder-type flat membrane in parallel placement in the practical application of SMBR,some sugges-tions are offered:the interval distance of membrane modules is 8―15 mm,and aeration should be op-erated at 5―7 mm among membrane modules,and the optimal design angle of trapeziform membrane is 1.7°―2.5°.

  7. Mathematical model analysis on the enhancement of aeration efficiency using ladder-type flat membrane module forms in the Submerged Membrane Bio-reactor (SMBR)

    LI Bo; YE MaoSheng; YANG FengLin; MA Hui

    2009-01-01

    The cross-flow shearing action produced from the inferior aeration in the Submerged Membrane Bio-reactor (SMBR) Is an effective way to further improve anti-fouling effects of membrane modules.Based on the widely-applied vertical structure of flat membrane modules, improvements are made that ladder-type flat membrane structure is designed with a certain inclined angle θ so that the cross-flow velocity of bubble near the membrane surface can be held, and the intensity and times of elastic colli-sion between bubbles and membrane surface can be increased. This can improve scouring action ofmembrane surface on aeration and reduce energy consumption of strong aeration in SMBR. By de-ducing and improving the mathematics model of collision between bubble and vertical flat put forward by Vries, the relatively suitable Incline angle θ under certain aeration place and in certain size rang ofbubble can be obtained with the computer iterative calculation technology. Finally, for many groups of ladder-type flat membrane in parallel placement in the practical application of SMBR, some sugges-tions are offered: the interval distance of membrane modules is 8--15 mm, and aeration should be op-erated at 5--7 mm among membrane modules, and the optimal design angle of trapeziform membrane is 1.7°--2.5°.

  8. ChillFish

    Sonne, Tobias; Jensen, Mads Møller

    2016-01-01

    Breathing exercises can help children with ADHD control their stress level, but it can be hard for a child to sustain attention throughout such an exercise. In this paper, we present ChillFish, a breath-controlled biofeedback game designed in collaboration with ADHD professionals to investigate...

  9. Fish Facts. Lesson Plan.

    Chan, Mike

    This lesson plan is designed for a 50-minute class to teach extension home economists and homemakers about buying, storing, and using fish. The lesson plan contains references, a list of equipment needed, objectives, and the presentation. The presentation consists of an outline of instruction coordinated with methods of instruction and aids and…

  10. Learning from Fish: Kinematics and Experimental Hydrodynamics for Roboticists

    George V. Lauder; Peter G. A. Madden

    2006-01-01

    Over the past 20 years, experimental analyses of the biomechanics of locomotion in fishes have generated a number of key findings that are relevant to the construction of biomimetic fish robots. In this paper, we present 16 results from recent experimental research on the mechanics, kinematics, fluid dynamics, and control of fish locomotion that summarize recent work on fish biomechanics. The findings and principles that have emerged from biomechanical studies of fish locomotion provide important insights into the functional design of fishes and suggest specific design features relevant to construction of robotic fish-inspired vehicles that underlie the high locomotor performance exhibited by fishes.

  11. Design and experiment of fishing device with electrical pulse for demersal fish in aquaculture pond%养殖池底层鱼类电脉冲捕捞装置设计与试验

    许明昌; 徐皓

    2011-01-01

    A user-friendly fishing instrument, with adjustable output pulse width and pulse frequency, status indication and alarm system, has been developed to alleviate the fishing labor intensity of demersal fish and to improve the fishing efficiency in aquaculture pond. The paper introduces the characteristics of electrical behaviors of fish, the mechanism of influence of electric field produced by discharge of pulse in water on fish behavior, determination of the electronic parameters and function of the system as well as the implementation and effect of the equipment.%为了减轻土池养殖底层鱼类的捕捞劳动强度,提高捕捞效率,研制了具有脉冲宽度和脉冲频率可调、工作状态指示、报警等功能,以及操作简单、使用方便的助渔仪器.文章主要介绍鱼类电行为特性、水中脉冲放电产生的电场对鱼类行为作用的机理、系统电气性能参数和系统功能的确定、硬件实施及效果等.

  12. 论悬鱼造型艺术对服装空间设计的启示%Inspiration fish hanging on the plastic arts of clothing space design

    陈宇刚

    2015-01-01

    Under the background of economic globalization, people pay more attention to the art of chasing nationality and localization features, this situation of clothing space design development of proposed new requirements. In this paper, China's traditional architectural style of art hanging fish, fish analysis hanging plastic arts in costume design in space applications. Hanging fish shape, with its unique aesthetic characteristics of our modern costume design space of great revelation, China's garment hanging space design can fish plastic arts inspiration for innovative design, combined with the characteristics of suspended fish plastic arts and traditional Chinese craft, rich modern costume design space.%在经济全球化的大背景下,人们对艺术的追求更加注重民族性和本土化特性,这一形势对服装空间设计发展提出了新的要求。本文结合我国传统建筑的悬鱼造型艺术,分析悬鱼造型艺术在服装空间设计中的应用。悬鱼造型凭借其独特的美学特点,对我国现代服装空间设计具有重大的启示,我国服装空间设计可以悬鱼造型艺术为创新设计灵感来源,结合悬鱼造型艺术的特点和我国传统工艺,丰富现代服装空间设计。

  13. Do Fish Enhance Tank Mixing?

    Rasmussen, Michael R.; Laursen, Jesper; Craig, Steven R.

    2005-01-01

    The design of fish rearing tanks represents a critical stage in the development of optimal aquaculture systems, especially in the context of recirculating systems. Poor hydrodynamics can compromise water quality, waste management and the physiology and behaviour of fish, and thence, production...... potential and operational profitability. The hydrodynamic performance of tanks, therefore, represents an important parameter during the tank design process. Because there are significant complexities in combining the rigid principles of hydrodynamics with the stochastic behaviour of fish, however, most data...... upon tank hydrokinetics has been derived using tanks void of fish. Clearly, the presence of randomly moving objects, such as fish, in a water column will influence not only tank volumes by displacing water, but due to their activity, water dynamics and associated in-tank processes. In order...

  14. Alabama ESI: FISH (Fish Polygons)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for marine, estuarine, and freshwater fish species in Alabama. Vector polygons in this data set represent...

  15. Virginia ESI: FISH (Fish Polygons)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for marine, estuarine, anadromous, and brackishwater fish species in Virginia. Vector polygons in this data...

  16. Maryland ESI: FISH (Fish Polygons)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for marine, estuarine, anadromous, and freshwater fish species in Maryland. Vector polygons in this data...

  17. Hawaii ESI: FISH (Fish Polygons)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for reef, marine, estuarine, and native stream fish species in coastal Hawaii. Vector polygons in this data...

  18. Louisiana ESI: FISH (Fish Polygons)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for freshwater (inland) fish species in coastal Louisiana. Vector polygons represent water-bodies and other...

  19. H-Bonding Self-assembled Template-directed Synthesis of a Reactive Amide-bridged Ladder Polyvinylsiloxane

    You Zhi WAN; Ying Hua LIU; Ping XIE; Rong Ben ZHANG

    2006-01-01

    A novel, reactive amide-bridged ladder polyvinylsiloxane (abbr. LP) with Mn = 2.4×104was synthesized for the first time by means of aryl amide H-bonding self-assembled template.The regularity of LP was characterized by the XRD, 29Si NMR and DSC methods. XRD analysis demonstrated the ladder width w = 9.09 A and the ladder thickness t = 3.89 A, respectively, which are approximately consistent with the molecular simulation-calculated ones: w'= 10.60 A and t'=3.06 A. 29Si NMR displayed a resonance peak with small half peak width, △1/2 ~ 4 ppm, for the moiety [=Si(Vi)O2/2-]n of LP. Besides, as a collateral evidence, DSC measurement revealed a high glass transition temperature Tg = 225℃, suggesting high stiffness of the ladder main chain of LP.

  20. Acupuncture plus Three-step Analgesic Ladder Principle for Cancer Pain Relief:Clinical Observation on 24 Cases

    ZHOU Yi; ZHONG Yi; HUANG Qin-feng; HAN Chou-ping

    2007-01-01

    To observe the therapeutic efficacy of acupuncture plus three-step analgesic ladder for cancer pain relief.Method:Thirty-siX cases with cancer pain were randomized into a treatment group and a control group.Twenty-four cases in the treatment group were treated with acupuncture plus three-step analgesic ladder approach and 12 cases in the control group were treated with three-step analgesic ladder approach alone.Result:The total effective rate and marked effect rate of the treatment group were 95.8%and 54.2% respectively,while those of the control group were 83.3%and 25.0%respectively,indicating a significant statistical difference (P<0.05) in terms of the therapeutic efficacy of the two groups and acupuncture plus three-step analgesic ladder approach can further improve the therapeutic efficacy.

  1. Using Commercial Games to Design Teacher-Made Games for the Mathematics Classroom.

    McBride, John W.; Lamb, Charles E.

    1991-01-01

    The use of commercial games to design and construct games to drill specific mathematics skills is discussed. Game types discussed include card games and board games. Two game boards adapted from "Chutes and Ladders" and "Battleship" are provided. (CW)

  2. Alkylphenols, Other Endocrine-Active Chemicals, and Fish Responses in Three Streams in Minnesota - Study Design and Data, February-September 2007

    Lee, Kathy E.; Schoenfuss, Heiko L.; Jahns, Nathan D.; Brown, Greg K.; Barber, Larry B.

    2008-01-01

    This report presents the study design and environmental data for an integrated chemical and biological study of three streams (South Fork Crow River, Redwood River, and Grindstone River) that receive wastewater in Minnesota. The objective of the study was to identify distribution patterns of endocrine-active chemicals and other organic chemicals indicative of wastewater, and to identify fish responses in the same streams. Endocrine-active chemicals are a class of chemicals that interfere with the natural regulation of endocrine systems, and an understanding of their distribution in aquatic systems is important so that aquatic organism exposure can be evaluated. This study was a cooperative effort of the U.S. Geological Survey (USGS), the Minnesota Pollution Control Agency, and St. Cloud State University (St. Cloud, Minn.). The USGS collected and analyzed water and quality-assurance samples and measured streamflow during six sampling events in each of three streams. Water samples were collected upstream from and at two successive points downstream from wastewater-treatment plant (WWTP) effluent discharge and from treated effluent from February through September 2007. Bed-sediment samples were collected during one sampling period at each of the stream locations. Water and bed-sediment samples were analyzed for endocrine-active chemicals including alkylphenols, alkylphenol polyethoxylates, and nonylphenol ethoxycarboxlylates (NPECs). Water samples also were analyzed for major ions, nutrients, and organic carbon. In addition, as part of an intensive time-series investigation, the USGS staff collected daily water samples for 8 weeks from the Redwood River near Marshall, Minn., for analyses of total alkylphenols and atrazine. St. Cloud State University staff collected and analyzed fish to determine male fish responses at all water sampling sites and at an additional site near the discharge of wastewater-treatment plant effluent to these streams. Male fish responses

  3. 46 CFR 72.05-20 - Stairways, ladders, and elevators.

    2010-10-01

    ... Main Vertical Zone without coming out of the stair tower enclosure. Each Type 1 stairway shall give... capacity. (ii) Crew staterooms—two-thirds designed capacity. (iii) Theaters, dining halls, and...

  4. Means-end chains and laddering: An inventory of problems and an agenda for research

    Grunert, Klaus G.; Beckmann, Suzanne C.; Sørensen, Elin

    2001-01-01

    to the collection and analysis of laddering data. However, many of these also point at problems of a more theoretical nature. In this chapter presented are some of the issues regarded as unresolved and suggested research that could help in solving these problems. The mayor part of this chapter deals......Laddering and means-end chains are one of the most promising developments in consumer research since the 1980s. It is an approach that takes consumers' individuality seriously but, nevertheless, comes up with quantitative results. It is rooted in a cognitive approach, and allows for emotional...... and unconscious (or, at least, semiconscious) factors. It is intuitively appealing to the practitioner but has, likewise, attracted academic research. Increased acceptance and use of a new approach inevitably leads to the detection of unresolved issues and problems. Many of these unresolved issues are related...

  5. Means-end chains and laddering: An inventory of problems and an agenda for research

    Grunert, Klaus G.; Grunert, Suzanne C.; Sørensen, Elin

    about products. Specifically, nonverbal imagery, episodic information, and procedural knowledge are not included in means-end chains. 3. A number of methodological problems can be identified in the collection of means-end chain data. Major problems, which should be addressed in research, are methods......Executive summary 1. Means-end chains are a device used to understand how consumers mentally link products to self-relevant consequences. Means-end chains are usually measured by a method called laddering. 2. Means-end chains may fall short of tapping all relevant aspects of how consumers think....... Hierarchical value maps, a major graphic device used to visualise results from laddering studies, should take care of possible non-homogeneity of respondents and of the intricacies of aggregation following from it. 6. A catalog of research topics is developed that can guide studies aimed at improving the means...

  6. Trait anxiety and goal difficulty on learning to climb the Bachman ladder.

    Neiva, Jaqueline F O; Barros, Joao A C; Meira, Cassio M

    2014-04-01

    This study examined the effects of trait anxiety and goal setting on learning of the Bachman ladder. It was hypothesized that easy goals would increase learning for individuals with high trait anxiety while hard goals would increase learning for individuals with low trait anxiety. 80 high school students (40 boys, 40 girls; M age = 15 yr., SD = 1.0) filled out the Brazilian State-Trait Anxiety Inventory (STAI) for trait anxiety. The experiment was divided into four phases: acquisition, immediate transfer (after 5 min.), delayed transfer, and retention (after 24 hr.). On the transfer phases, the participants started climbing the ladder with the foot opposite of that used in acquisition. Participants were assigned to one of four experimental groups combining high and low anxiety traits and hard and easy goals. Variances were analyzed with repeated measurements on the last factor of all phases. The results showed the performance increased during the acquisition phase and no effects were observed in any phases.

  7. Effects of spontaneously induced coherence on absorption of a ladder-type atom

    Ma Hong-Mei; Gong Shang-Qing; Sun Zhen-Rong; Li Ru-Xin; Xu Zhi-Zhan

    2006-01-01

    This paper investigates the effects of spontaneously induced coherence on absorption properties in a nearly equispaced three-level ladder-type system driven by two coherent fields. It find that the absorption properties of this system with the probe field applied on the lower transition can be significantly modified if this coherence is optimized. In the case of small spontaneous decay rate in the upper excited state, it finds that such coherence does not destroy the electromagnetically induced transparency (EIT). Nevertheless, the absorption peak on both sides of zero detuning and the linewidth of absorption line become larger and narrower than those in the case corresponding to the effects of spontaneously induced coherence; while in the case of large decay rate, it finds that, instead of EIT with low resonant absorption, a sharp absorption peak at resonance appears. That is, electromagnetically induced absorption in the nearly equispaced ladder-type system can occur due to such coherent effects.

  8. On Ladder Diagrams Compilation and Synthesis to FPGA Implemented Reconfigurable Logic Controller

    Adam Milik

    2014-01-01

    Full Text Available The paper presents synthesis process of a hardware implemented reconfigurable logic controller from a ladder diagram according to IEC61131-3 requirements. It is focused on the originally developed a high-performance LD processing method. It is able to process a set of diagrams restricted to logic operations in a single clock cycle independently from the number of processed rungs. The paper considers the compilation of the ladder diagram into an intermediate form suitable for logic synthesis process according to developed processing method. The enhanced data flow graph (EDFG has been developed for the intermediate representation of an LD program. The original construction of the EDFG with attributed edges has been described. It allows for efficient representation and processing of logic and arithmetic formulas. The set of compilation algorithms that allow to preserve serial analysis order and to obtain massively parallel processing unit are presented. The overview of a hardware mapping concludes the presented considerations.

  9. The antiferromagnetic cross-coupled spin ladder: Quantum fidelity and tensor networks approach

    Chen, Xi-Hao; Cho, Sam Young; Zhou, Huan-Qiang; Batchelor, Murray T.

    2016-05-01

    We investigate the phase diagram of the cross-coupled Heisenberg spin ladder with antiferromagnetic couplings. For this model, the results for the existence of the columnar dimer phase, which was predicted on the basis of weak coupling field theory renormalization group arguments, have been conflicting. The numerical work on this model has been based on various approaches, including exact diagonalization, series expansions and density-matrix renormalization group calculations. Using the recently-developed tensor network states and groundstate fidelity approach for quantum spin ladders, we find no evidence for the existence of the columnar dimer phase. We also provide an argument based on the symmetry of the Hamiltonian, which suggests that the phase diagram for antiferromagnetic couplings consists of a single line separating the rung-singlet and the Haldane phases.

  10. H-bonding template-directed synthesis of a complete m-PDA-bridged ladder polyhydrosiloxane (OLPHS)

    2007-01-01

    A highly ordered m-phenylenediimino-bridged ladder polyhydrosiloxane (abbr. OLPHS) with Mn = 1.24 × 104 was synthesized stoichiometric hydrolysis and dehydrochlorination condensation reaction between Si-Cl and Si-OH bonds. The complete ladder structure of OLPHS has been confirmed by the following three data. Two characteristic Bragg's peaks representing the ladder width (w = 0.94 nm) and ladder thickness (t = 0.42 nm) were observed in XRD analysis, which are consistent with those calculated by molecular simulation. The very sharp absorption with a small half-peak width (w1/2 = 0.5 ppm) for [(-HN)HSiO2/2]n moiety of OLPHS in 29Si NMR spectrum indicated presence of the complete ladder structure. As collateral evidence, a higher glass transition temperature (Tg = 105 ℃) is also recorded in the DSC measurement, implying the high stiffness of ladder chain of OLPHS.(C) 2007 Rong Ben Zhang. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

  11. Fishing Access Areas

    Vermont Center for Geographic Information — The Vermont Fish & Wildlife Department maintains developed fishing access areas. These sites provide public access to waters in Vermont for shore fishing...

  12. Variation of the absorption and dispersion profiles in a ladder-four-level system

    Li Yong-Fang; Sun Jian-Feng; Niu Yue-Ping

    2004-01-01

    A theoretical research on the variation of the absorption and dispersion profiles and population distribution of each level in a ladder-four-level system driven by two coherent fields has been made. Whether the variation occurs or not depends on the effect of quantum interference, the detuning of the upper coherent field and the separation of the two intermediate levels. A dressed-state analysis is introduced to explain the numerical results.

  13. Specific heat spectra of non-interacting fermions in a quasiperiodic ladder sequence

    Moreira, D. A.; Albuquerque, E. L.; Anselmo, D. H. A. L.

    2008-07-01

    We compute the specific heat spectra of non-interacting fermions whose energy spectrum was obtained from a quasiperiodic ladder sequence (Fibonacci and Rudin-Shapiro type), mimicking a DNA molecule model. The specific heat is calculated from their underlying multi-fractal energy spectrum, considering several values of energy densities. Comparisons are made with a real DNA sequence, namely the human chromosome 22 (Ch22).

  14. Telecast of Astronaut Neil Armstrong descending ladder to surface of the moon

    1969-01-01

    Astronaut Neil A. Armstrong, Apollo 11 commander, descends the ladder of the Apollo 11 Lunar Module prior to making the first step by man on the moon. This view is a black and white reproduction taken from a telecast by the Apollo 11 lunar surface camera during extravehicular activity. The black bar running through the center of the picture is an anamoly in the television ground data system at the Goldstone Tracking Station.

  15. Automatic Tracking Radar Career Ladder, AFSC-303X3. Electronics Principles Inventory (EPI).

    1981-02-01

    81 UNCLASSIFIED NL mhhmI/I/II///IEEIIIIEIIIIIEE EIIIIEEEEIIIII UNITED STATES AIR FORCE ELECTRONICS PRINCIPLES INVENTORY (EPI),., / b AUTOMATIC...presents the preliminary results of an Air Force Electronics Principles Survey of the Automatic Tracking Radar career ladder (AFSC 303X3). The project was...undertaken at the request of Mr. James R. Haupt, Training Manager, Keesler AFB, MS. Authority for conducting electronics principles inventories is

  16. Fabrication of nanochannels with ladder nanostructure at the bottom using AFM nanoscratching method

    2014-01-01

    This letter presents a novel atomic force microscopy (AFM)-based nanomanufacturing method combining the tip scanning with the high-precision stage movement to fabricate nanochannels with ladder nanostructure at the bottom by continuous scanning with a fixed scan size. Different structures can be obtained according to the matching relation of the tip feeding velocity and the precision stage moving velocity. This relationship was first studied in detail to achieve nanochannels with different la...

  17. Specific heat spectra of non-interacting fermions in a quasiperiodic ladder sequence

    Moreira, D.A. [Departamento de Fisica, Universidade Federal do Rio Grande do Norte, 59072-970 Natal-RN (Brazil); Albuquerque, E.L. [Departamento de Fisica, Universidade Federal do Rio Grande do Norte, 59072-970 Natal-RN (Brazil)], E-mail: eudenilson@dfte.ufrn.br; Anselmo, D.H.A.L. [Departamento de Fisica, Universidade Federal do Rio Grande do Norte, 59072-970 Natal-RN (Brazil)

    2008-07-28

    We compute the specific heat spectra of non-interacting fermions whose energy spectrum was obtained from a quasiperiodic ladder sequence (Fibonacci and Rudin-Shapiro type), mimicking a DNA molecule model. The specific heat is calculated from their underlying multi-fractal energy spectrum, considering several values of energy densities. Comparisons are made with a real DNA sequence, namely the human chromosome 22 (Ch22)

  18. The genus polynomials of cross-ladder digraphs in orientable surfaces

    2008-01-01

    Some results about the genus distributions of graphs are known,but little is known about those of digraphs.In this paper,the method of joint trees initiated by Liu is generalized to compute the embedding genus distributions of digraphs in orientable surfaces.The genus polynomials for a new kind of 4-regular digraphs called the cross-ladders in orientable surfaces are obtained.These results are close to solving the third problem given by Bonnington et al.

  19. Resonant states and wavepacket super-diffusion in intra-chain correlated ladders with diluted disorder.

    de Moura, F A B F; Leão, F F S; Lyra, M L

    2011-04-06

    In this work, we study a tight-binding Hamiltonian model system of a binary correlated ladder with diluted disorder. We introduce intra-chain correlations between the on-site potentials by imposing that ϵ(i, s) = - ϵ(i, - s) where s = ± 1 indexes the two ladder chains. Further, we consider each ladder chain as composed of inter-penetrating ordered and random sub-chains. We show that the presence of a random on-site distribution in one of the inter-penetrating chains leads to Anderson localization except at a specific symmetric pair of energy eigenmodes. Further, by integrating the time-dependent Schroedinger equation, we follow the time-evolution of an initially localized one-electron wavepacket. We report that the remaining delocalized resonant modes are responsible for a super-diffusive spread of the wavepacket dispersion while the wavepacket participation function remains finite. A scaling analysis of the wavepacket distribution shows that it obeys a universal scaling form with the development of a power-law tail followed by a super-diffusively evolving cutoff. We obtain three exponents characterizing this super-diffusive dynamics and show that they satisfy a simple scaling relation.

  20. Chiral Mott insulators, Meissner effect, and Laughlin states in quantum ladders

    Petrescu, Alexandru; Le Hur, Karyn

    2015-02-01

    We introduce generic bosonic models exemplifying that chiral Meissner currents can persist in insulating phases of matter. We first consider interacting bosons on a two-leg ladder. The total density sector can be gapped in a bosonic Mott insulator at odd-integer filling, while the relative density sector remains superfluid due to interchain hopping. Coupling the relative density to gauge fields yields a pseudospin Meissner effect. We show that the same phase arises if the bosons are replaced by spinful fermions confined in Cooper pairs, and find a dual fermionic Mott insulator with spinon currents. We prove that, by tuning the mean density, the Mott insulator with Meissner currents turns into a low-dimensional bosonic ν =1/2 Laughlin state for strong enough repulsive interactions across the ladder rungs. We finally discuss extensions to multileg ladders and bilayers in which spinon superfluids with Meissner currents become possible. We propose two experimental realizations, one with ultracold atoms in the setup of Atala et al. [Nat. Phys. 10, 588 (2014), 10.1038/nphys2998] and another with Josephson junction arrays. We also address a Bose-Fermi mixture subject to a magnetic field in connection with the pseudogap phase of high-Tc cuprates.

  1. Topic Order in Introductory Physics and its Impact on the STEM Curricular Ladder

    Teresa L Larkin

    2017-02-01

    Full Text Available Introductory physics courses are an important rung on the curricular ladder in STEM. These courses help to strengthen students critical thinking and problem solving skills while simultaneously introducing them to many topics they will explore in more detail in later courses in physics and engineering. For these reasons, introductory physics is a required element on the curricular ladder. Most often, introductory physics is offered as a two-semester sequence with basic mechanics being taught in the first semester and electricity and magnetism in the second. In fact, this curricular sequence has not been altered in decades. Is there a reason for this? There are many other enduring questions that arise pertaining to these foundation courses in physics. These questions include: Does taking the introductory course sequence “out of order” have an impact on student learning in physics? What topics should be taught? When should these topics be taught? What topics could be left out? The list of questions is essentially endless. This paper will address some of these questions in part, through a brief discussion on student learning in a second-semester algebra-based physics course. Connections will also be made to the broader curricular ladder in STEM. To this end, an illustration that makes connections to an engineering statics course will be presented. This discussion will conclude by presenting some broader implications for the larger STEM communities.

  2. The Pan-STARRS 1 Photometric Reference Ladder, Release 12.0

    Magnier, E A; Finkbeiner, D; Juric, M; Tonry, J L; Burgett, W S; Chambers, K C; Flewelling, H A; Kaiser, N; Kudritzki, R -P; Morgan, J S; Price, P A; Sweeney, W E; Stubbs, C W

    2013-01-01

    As of 2012 Jan 21, the Pan-STARRS 1 3\\pi Survey has observed the 3/4 of the sky visible from Hawaii with a minimum of 2 and mean of 7.6 observations in 5 filters, g_p1, r_p1, i_p1, z_p1, y_p1. Now at the end of the second year of the mission, we are in a position to make an initial public release of a portion of this unprecedented dataset. This article describes the PS1 Photometric Ladder, Release 12.01 This is the first of a series of data releases to be generated as the survey coverage increases and the data analysis improves. The Photometric Ladder has rungs every hour in RA and at 4 intervals in declination. We will release updates with increased area coverage (more rungs) from the latest dataset until the PS1 survey and the final re-reduction are completed. The currently released catalog presents photometry of \\approx 1000 objects per square degree in the rungs of the ladder. Saturation occurs at g_p1, r_p1, i_p1 \\approx 13.5; z_p1 \\approx 13.0; and y_p1 \\approx 12.0. Photometry is provided for stars dow...

  3. First-order commensurate-incommensurate magnetic phase transition in the coupled FM spin-1/2 two-leg ladders

    Jahangiri, J; Mahdavifar, S; Shayesteh, S Farjami

    2015-01-01

    We consider the spin-1/2 two-leg ladders with ferromagnetic (FM) interactions along legs and rungs. Using the stochastic series expansion QMC method, we study the low-temperature magnetic behavior of the system. An isolated spin-1/2 FM two-leg ladder is in the gapped saturated FM phase at zero temperature. As soon as the spin-1/2 FM two-leg ladders are connected with antiferromagnetic (AFM) inter-ladder interaction, a first-order commensurate-incommensurate quantum phase transition occurs in the ground state magnetic phase diagram. In fact a jump in the magnetization curve is observed. We found that, coupled spin-1/2 FM two-leg ladders are in a nonmagnetic phase at zero temperature. Applying a magnetic field, the ground state of coupled spin-1/2 FM two-leg ladders remains in the nonmagnetic phase up to a quantum saturate critical field.

  4. The Fishing Cat

    孙雅飞; 乐伟国

    2008-01-01

    @@ 一、故事内容 A cat goes fishing every day. He wants to eat fish, but he can't catch any fish. One day, he goes to the river as usual. Suddenly, a fish comes out. He catches the fish and putsthe fish in the basket. He's very happy, but he forgest to put the lid on the basket.

  5. D0 Silicon Upgrade: Thermally Induced Stresses in the Components of a D0 Ladder in the Silicon Tracker

    Ratzmann, Paul M.; /Fermilab

    1996-07-02

    During the operation of the silicon tracker, the ladders will be in direct thermal contact with a cooling channel. The expected operating temperature of the cooling channel is 0 C, maintained by a cooling fluid whose bulk temperature is below 0 C. The assembly temperature is assumed to be 22 C. Due to the mis-match of material expansion coefficients, thermal stresses will be induced in the epoxy, beryllium, and silicon of the ladders. Calculations are presented here as well as some thermal cycling results on test samples. Shown in Figures 1 and 2 are perspective views of the top and bottom of a 3 chip ladder. The silicon temperature within the ladders will not be uniform due to the relative location of the heat dissipating components and the cooling channel. As an example the following plot demonstrates the expected temperature distribution in the 3 chip single sided ladder during operation. Under expected operating conditions of 0.75 W hybrid component power dissipation and 0.5 W per SVX II chip, the temperature profile is shown for two situations of how the ladder is constructed. The cooling channel corresponds roughly to locations on the silicon between 32 and 42 mm. The silicon in this region is sandwiched between two plates of beryllium and is about 4 C. For a construction temperature of 22 C the beryllium/silicon/beryllium assembly will see a 18 C change in temperature. To be conservative a 20 C temperature change will be assumed (some larger temperature extremes will be considered) within the ladder.

  6. Quantum Superlattices, Wannier Stark Ladders and the 'Resonance' technique

    Papageorgiou, C D; Raptis, T E

    2016-01-01

    We present a new method for solving the Schrodinger equation using the Lossless Transmission Line Model (LTL). The LTL model although extensively used in fiber optics and optical fiber design, it has not yet found application in solid state problems. We develop the transformation theory mapping the wave equation to LTL and we apply the model to the case of a solid state periodic lattice. We extend the theory with an additional Wannier-Stark term and we show with results the flexibility and the strength of the technique. The advantages of the method for arbitrary potentials are also stressed.

  7. Fish gelatin.

    Boran, Gokhan; Regenstein, Joe M

    2010-01-01

    Gelatin is a multifunctional ingredient used in foods, pharmaceuticals, cosmetics, and photographic films as a gelling agent, stabilizer, thickener, emulsifier, and film former. As a thermoreversible hydrocolloid with a narrower gap between its melting and gelling temperatures, both of which are below human body temperature, gelatin provides unique advantages over carbohydrate-based gelling agents. Gelatin is mostly produced from pig skin, and cattle hides and bones. Some alternative raw materials have recently gained attention from both researchers and the industry not just because they overcome religious concerns shared by Jews and Muslims but also because they provide, in some cases, technological advantages over mammalian gelatins. Fish skins from a number of fish species are among the other sources that have been comprehensively studied as sources for gelatin production. Fish skins have a significant potential for the production of high-quality gelatin with different melting and gelling temperatures over a much wider range than mammalian gelatins, yet still have a sufficiently high gel strength and viscosity. Gelatin quality is industrially determined by gel strength, viscosity, melting or gelling temperatures, the water content, and microbiological safety. For gelatin manufacturers, yield from a particular raw material is also important. Recent experimental studies have shown that these quality parameters vary greatly depending on the biochemical characteristics of the raw materials, the manufacturing processes applied, and the experimental settings used for quality control tests. In this review, the gelatin quality achieved from different fish species is reviewed along with the experimental procedures used to determine gelatin quality. In addition, the chemical structure of collagen and gelatin, the collagen-gelatin conversion, the gelation process, and the gelatin market are discussed.

  8. Fish hemoglobins

    P.C. de Souza

    2007-06-01

    Full Text Available Vertebrate hemoglobin, contained in erythrocytes, is a globular protein with a quaternary structure composed of 4 globin chains (2 alpha and 2 beta and a prosthetic group named heme bound to each one. Having myoglobin as an ancestor, hemoglobin acquired the capacity to respond to chemical stimuli that modulate its function according to tissue requirements for oxygen. Fish are generally submitted to spatial and temporal O2 variations and have developed anatomical, physiological and biochemical strategies to adapt to the changing environmental gas availability. Structurally, most fish hemoglobins are tetrameric; however, those from some species such as lamprey and hagfish dissociate, being monomeric when oxygenated and oligomeric when deoxygenated. Fish blood frequently possesses several hemoglobins; the primary origin of this finding lies in the polymorphism that occurs in the globin loci, an aspect that may occasionally confer advantages to its carriers or even be a harmless evolutionary remnant. On the other hand, the functional properties exhibit different behaviors, ranging from a total absence of responses to allosteric regulation to drastic ones, such as the Root effect.

  9. Belle II SVD ladder assembly procedure and electrical qualification

    Adamczyk, K.; Aihara, H.; Angelini, C.; Aziz, T.; Babu, Varghese; Bacher, S.; Bahinipati, S.; Barberio, E.; Baroncelli, T.; Basith, A. K.; Batignani, G.; Bauer, A.; Behera, P. K.; Bergauer, T.; Bettarini, S.; Bhuyan, B.; Bilka, T.; Bosi, F.; Bosisio, L.; Bozek, A.; Buchsteiner, F.; Casarosa, G.; Ceccanti, M.; Červenkov, D.; Chendvankar, S. R.; Dash, N.; Divekar, S. T.; Doležal, Z.; Dutta, D.; Forti, F.; Friedl, M.; Hara, K.; Higuchi, T.; Horiguchi, T.; Irmler, C.; Ishikawa, A.; Jeon, H. B.; Joo, C.; Kandra, J.; Kang, K. H.; Kato, E.; Kawasaki, T.; Kodyš, P.; Kohriki, T.; Koike, S.; Kolwalkar, M. M.; Kvasnička, P.; Lanceri, L.; Lettenbicher, J.; Mammini, P.; Mayekar, S. N.; Mohanty, G. B.; Mohanty, S.; Morii, T.; Nakamura, K. R.; Natkaniec, Z.; Negishi, K.; Nisar, N. K.; Onuki, Y.; Ostrowicz, W.; Paladino, A.; Paoloni, E.; Park, H.; Pilo, F.; Profeti, A.; Rao, K. K.; Rashevskaya, I.; Rizzo, G.; Rozanska, M.; Sandilya, S.; Sasaki, J.; Sato, N.; Schultschik, S.; Schwanda, C.; Seino, Y.; Shimizu, N.; Stypula, J.; Tanaka, S.; Tanida, K.; Taylor, G. N.; Thalmeier, R.; Thomas, R.; Tsuboyama, T.; Uozumi, S.; Urquijo, P.; Vitale, L.; Volpi, M.; Watanuki, S.; Watson, I. J.; Webb, J.; Wiechczynski, J.; Williams, S.; Würkner, B.; Yamamoto, H.; Yin, H.; Yoshinobu, T.

    2016-07-01

    The Belle II experiment at the SuperKEKB asymmetric e+e- collider in Japan will operate at a luminosity approximately 50 times larger than its predecessor (Belle). At its heart lies a six-layer vertex detector comprising two layers of pixelated silicon detectors (PXD) and four layers of double-sided silicon microstrip detectors (SVD). One of the key measurements for Belle II is time-dependent CP violation asymmetry, which hinges on a precise charged-track vertex determination. Towards this goal, a proper assembly of the SVD components with precise alignment ought to be performed and the geometrical tolerances should be checked to fall within the design limits. We present an overview of the assembly procedure that is being followed, which includes the precision gluing of the SVD module components, wire-bonding of the various electrical components, and precision three dimensional coordinate measurements of the jigs used in assembly as well as of the final SVD modules.

  10. Occurrence of monogeneans on freshwater fishes in Iran: Dactylogyrus spp. on cultured Iranian fishes.

    Jalali, B; Molnár, K

    1990-01-01

    Thirteen Dactylogyrus spp. were found on cultured fishes in five Iranian fish farms. Besides typical Dactylogyrus vastator, specimens with small anchors were often found in goldfish, which were designated as D. vastator forma minor. Rutilus frisii kutum, a fish cultured only in Iran, was infected by two Dactylogyrus spp. during its short period of prerearing in Iranian fish farms. All Dactylogyrus found are new for the Iranian fauna.

  11. Crossover from Electromagnetically Induced Transparency to Autler-Townes Splitting in Open Ladder Systems with Doppler Broadening

    Tan, Chaohua

    2013-01-01

    We propose a general theoretical scheme to investigate the crossover from electromagnetically induced transparency (EIT) to Autler-Townes splitting (ATS) in open ladder-type atomic and molecular systems with Doppler broadening. We show that when the wavenumber ratio $k_c/k_p\\approx -1$, EIT, ATS, and EIT-ATS crossover exist for both ladder-I and ladder-II systems, where $k_c$ ($k_p$) is the wavenumber of control (probe) field. Furthermore, when $k_c/k_p$ is far from $-1$ EIT can occur but ATS is destroyed if the upper state of the ladder-I system is a Rydberg state. In addition, ATS exists but EIT is not possible if the control field used to couple the two lower states of the ladder-II system is a microwave field. The theoretical scheme developed here can be applied to atoms, molecules, and other systems (including Na$_2$ molecules, and Rydberg atoms), and the results obtained may have practical applications in optical information processing and transformation.

  12. Hood River and Pelton Ladder Evaluation Studies and Hood River Fish Habitat Project, 1998 Annual Progress Report.

    Lambert, Michael B.; McCanna, Joseph P.; Jennings, Mick

    1999-12-01

    The Hood River subbasin is home to four species of anadromous salmonids: chinook salmon (Oncorhynchus tshawytscha), coho salmon (Oncorhynchus kisutch), steelhead (Oncorhynchus mykiss), and sea run cutthroat trout (Salmo clarki). Indigenous spring chinook salmon were extirpated during the late 1960's. The naturally spawning spring chinook salmon currently present in the subbasin are progeny of Deschutes stock. Historically, the Hood River subbasin hatchery steelhead program utilized out-of-basin stocks for many years. Indigenous stocks of summer and winter steelhead were listed in March 1998 by National Marine Fisheries Service (NMFS) under the Endangered Species Act (ESA) as a ''Threatened'' Species along with similar genetically similar steelhead in the Lower Columbia Basin.

  13. Donor-acceptor conjugated polymers based on multifused ladder-type arenes for organic solar cells.

    Wu, Jhong-Sian; Cheng, Sheng-Wen; Cheng, Yen-Ju; Hsu, Chain-Shu

    2015-03-07

    Harvesting solar energy from sunlight to generate electricity is considered as one of the most important technologies to address the future sustainability of humans. Polymer solar cells (PSCs) have attracted tremendous interest and attention over the past two decades due to their potential advantage to be fabricated onto large area and light-weight flexible substrates by solution processing at a lower cost. PSCs based on the concept of bulk heterojunction (BHJ) configuration where an active layer comprises a composite of a p-type (donor) and an n-type (acceptor) material represents the most useful strategy to maximize the internal donor-acceptor interfacial area allowing for efficient charge separation. Fullerene derivatives such as [6,6]-phenyl-C61 or 71-butyric acid methyl ester (PCBM) are the ideal n-type materials ubiquitously used for BHJ solar cells. The major effort to develop photoactive materials is numerously focused on the p-type conjugated polymers which are generally synthesized by polymerization of electron-rich donor and electron-deficient acceptor monomers. Compared to the development of electron-deficient comonomers (acceptor segments), the development of electron-rich donor materials is considerably flourishing. Forced planarization by covalently fastening adjacent aromatic and heteroaromatic subunits leads to the formation of ladder-type conjugated structures which are capable of elongating effective conjugation, reducing the optical bandgap, promoting intermolecular π-π interactions and enhancing intrinsic charge mobility. In this review, we will summarize the recent progress on the development of various well-defined new ladder-type conjugated materials. These materials serve as the superb donor monomers to prepare a range of donor-acceptor semi-ladder copolymers with sufficient solution-processability for solar cell applications.

  14. Scaffolding, ladders, chains, and rare ferrimagnetism in intermetallic borides: synthesis, crystal chemistry and magnetism.

    Goerens, Christian; Brgoch, Jakoah; Miller, Gordon J; Fokwa, Boniface P T

    2011-07-04

    Single-phase polycrystalline samples and single crystals of the complex boride phases Ti(8)Fe(3)Ru(18)B(8) and Ti(7)Fe(4)Ru(18)B(8) have been synthesized by arc melting the elements. The phases were characterized by powder and single-crystal X-ray diffraction as well as energy-dispersive X-ray analysis. They are new substitutional variants of the Zn(11)Rh(18)B(8) structure type, space group P4/mbm (no. 127). The particularity of their crystal structure lies in the simultaneous presence of dumbbells which form ladders of magnetically active iron atoms along the [001] direction and two additional mixed iron/titanium chains occupying Wyckoff sites 4h and 2b. The ladder substructure is ca. 3.0 Å from the two chains at the 4h, which creates the sequence chain-ladder-chain, establishing a new structural and magnetic motif, the scaffold. The other chain (at 2b) is separated by at least 6.5 Å from this scaffold. According to magnetization measurements, Ti(8)Fe(3)Ru(18)B(8) and Ti(7)Fe(4)Ru(18)B(8) order ferrimagnetically below 210 and 220 K, respectively, with the latter having much higher magnetic moments than the former. However, the magnetic moment observed for Ti(8)Fe(3)Ru(18)B(8) is unexpectedly smaller than the recently reported Ti(9)Fe(2)Ru(18)B(8) ferromagnet. The variation of the magnetic moments observed in these new phases can be adequately understood by assuming a ferrimagnetic ordering involving the three different iron sites. Furthermore, the recorded hysteresis loops indicate a semihard magnetic behavior for the two phases. The highest H(c) value (28.6 kA/m), measured for Ti(7)Fe(4)Ru(18)B(8), lies just at the border of those of hard magnetic materials.

  15. Blood and tissue fatty acid compositions, lipoprotein levels, performance and meat flavor of broilers fed fish oil: changes in the pre- and post-withdrawal design.

    Aghaei, N; Safamehr, A; Mehmannavaz, Y; Chekaniazar, S

    2012-12-01

    Administration of fish oil (FO) in broiler diets can elevate α-linolenic acid (ALA), eicosapentanoic acid (EPA) and docosahexanoic acid (DHA) levels, which are protective against cardiovascular disease. However, optimization based solely on n-3 polyunsaturated fatty acid (n-3 PUFA) enrichment in chicken meat could lead to lower meat quality, unless the withdrawal period (plan) is applied for 1 week. The present study investigated whether the incorporation of FO in the diet for 32 days followed by its withdrawal for 1 week affected blood lipid profiles, lipoprotein particles, performance and meat flavor in male broiler chickens. Two hundred and forty birds (1-day-old, Ross 308) were assigned to 1 of 4 dietary groups: 0%, 1%, 2% or 3% FO with four replicates. Broilers were fed for 49 days according to a 4-phase feeding program. The experimental phase comprised day 11 to 42, and FO was removed on day 42. Blood samples were collected during the pre- and post-withdrawal period after the recordings before slaughter. The FO groups demonstrated decreased low-density lipoprotein (LDL) and increased high-density lipoprotein levels on day 42 (P after design withdrawal. Diet supplementation with FO elevated the blood levels of palmitic acid (C16:0) and n-3 PUFAs, especially long-chain (LC) PUFAs (EPA, C20:5n-3 and DHA, C22:6n-3), and caused a decline in the level of arachidonic acid (AA, C20:4n-6; P after institution of the withdrawal design. Degradation of total n-3 FAs deposited in tissues occurred after instituting the withdrawal plan diet, but deposited levels of EPA and DHA in tissues could ensure omega-3 enrichment of broiler meat in groups 3 and 4. On the basis of the dissatisfaction of the panelists toward group 4 meats (scored as near to acceptable) and their satisfaction with cooked samples of T3 (scored as good), group 3 meats were selected as good-quality n-3-enriched broiler meat.

  16. Fish Tales

    McLerran, L.

    2010-07-06

    This talk is about fishing and the friendships that have resulted in its pursuit. It is also about theoretical physics, and the relationship of imagination and fantasy to the establishment of ideas about nature. Fishermen, like theoretical physicists, are well known for their inventive imaginations. Perhaps neither are as clever as sailors, who conceived of the mermaid. If one doubts the power of this fantasy, one should remember the ghosts of the many sailors who drowned pursuing these young nymphs. An extraordinary painting by J. Waterhouse is shown as Fig. 1. The enchantment of a mermaid must reflect an extraordinary excess of imagination on the part of the sailor, perhaps together with an impractical turn of mind. A consummated relationship with a mermaid is after all, by its very nature a fantasy incapable of realization. To a theoretical physicist, she is symbolic of many ideas we develop. There are many truths known to fisherman in which one might also find parallels to the goals of scientists: (1) A fish is the only animal that keeps growing after its death; (2) Nothing makes a fish bigger than almost being caught; (3) ''...of all the liars among mankind, the fisherman is the most trustworthy.'' (William Sherwood Fox, in Silken Lines and Silver Hooks); and (4) Men and fish are alike. They both get into trouble when they open their mouths. These quotes may be interpreted as reflecting skepticism regarding the honesty of fisherman, and probably do not reflect adequate admiration for a creative imagination. Is it fair to criticize a person for believing a falsehood that he or she sincerely believes to be true? The fisherman simultaneously invents the lie, and believes in it himself. The parallel with theoretical physics is perhaps only approximate, although we physicists may invent stories that we come to believe, on some rare occasions our ideas actually correspond to a more or less true descriptions of nature. These minor philosophical

  17. Fish Immunoglobulins

    Mashoof, Sara; Criscitiello, Michael F.

    2016-01-01

    The B cell receptor and secreted antibody are at the nexus of humoral adaptive immunity. In this review, we summarize what is known of the immunoglobulin genes of jawed cartilaginous and bony fishes. We focus on what has been learned from genomic or cDNA sequence data, but where appropriate draw upon protein, immunization, affinity and structural studies. Work from major aquatic model organisms and less studied comparative species are both included to define what is the rule for an immunoglobulin isotype or taxonomic group and what exemplifies an exception. PMID:27879632

  18. Electromagnetically induced absorption in a non-degenerate three-level ladder system

    Whiting, Daniel J; Keaveney, James; Zentile, Mark A; Adams, Charles S; Hughes, Ifan G

    2015-01-01

    We investigate, theoretically and experimentally, the transmission of light through a thermal vapour of three-level ladder-type atoms, in the presence of 2 counter-propagating control fields. A simple theoretical model predicts the presence of electromagnetically induced absorption (EIA) in this pure three-level system when the control field is resonant. Experimentally, we use $^{87}$Rb in a large magnetic field of 0.62~T to reach the hyperfine Paschen-Back regime and realise a non-degenerate three-level system. Experimental observations verify the predictions over a wide range of detunings.

  19. Ladder-type electromagnetically induced transparency using nanofiber-guided light in a warm atomic vapor

    Jones, D E; Pittman, T B

    2015-01-01

    We demonstrate ladder-type electromagnetically induced transparency (EIT) using an optical nanofiber suspended in a warm rubidium vapor. The signal and control fields are both guided along the nanofiber, which enables strong nonlinear interactions with the surrounding atoms at relatively low powers. Transit-time broadening is found to be a significant EIT decoherence mechanism in this tightly-confined waveguiding geometry. Nonetheless, we observe significant EIT and controlled polarization rotation using control-field powers of only a few microWatts in this relatively robust warm-atom nanofiber system.

  20. Emergent Interacting Spin Islands in a Depleted Strong-Leg Heisenberg Ladder.

    Schmidiger, D; Povarov, K Yu; Galeski, S; Reynolds, N; Bewley, R; Guidi, T; Ollivier, J; Zheludev, A

    2016-06-24

    Properties of the depleted Heisenberg spin ladder material series (C_{7}H_{10}N)_{2}Cu_{1-z}Zn_{z}Br_{4} have been studied by the combination of magnetic measurements and neutron spectroscopy. Disorder-induced degrees of freedom lead to a specific magnetic response, described in terms of emergent strongly interacting "spin island" objects. The structure and dynamics of the spin islands is studied by high-resolution inelastic neutron scattering. This allows us to determine their spatial shape and to observe their mutual interactions, manifested by strong spectral in-gap contributions.

  1. A Study of Regional Brand Positioning Strategy for Linhai Orange Based on Soft Laddering

    Ying; TAO; Yueli; ZHANG

    2015-01-01

    In this paper,Means-End Chain Theory is used for the positioning strategy study on regional brand of Linhai Orange,and based on soft laddering method,33 Linhai Orange consumers are interviewed. By understanding the individual needs of Linhai Orange consumers,this paper establishes the " Attributes-Consequences-Value" matrix and hierarchical value map. This study aims to explore the regional brand positioning strategy of Linhai Orange,in order to promote the regional brand building and extension of Linhai Orange and enhance the sustained regional brand development of Linhai Orange.

  2. Absorption properties of a driven Doppler-broadened ladder system with hyperfine structure

    吴金辉; 高锦岳

    2002-01-01

    We have studied the absorption spectrum of a Doppler-broadened ladder system, where the highest level is coupled into two middle hyperfine sublevels by a strong coherent field. We find that, when the system is considered as homoge- neous, either two or three spectral components are observed, depending on the detuning of the coherent field. But when the velocity distribution of atoms is considered, we can always observe one electromagnetically induced transparency (EIT) window with high dispersion. So the atomic hyperfine structure cannot be an impediment for obtaining EIT.

  3. Population transfer by femtosecond laser pulses in a ladder-type atomic system

    Fan Xi-Jun; Li Ai-Yun; Tong Dian-Min; Liu Cheng-Pu

    2008-01-01

    The population transfer in a ladder-type atomic system driven by linearly polarized sech-shape femtosecond laser pulses is investigated by numerically solving Schrodinger equation without including the rotating wave approximation (RWA). It is shown that population transfer is mainly determined by the Rabi frequency (strength) of the driving laser field and the chirp rate, and that the ratio of the dipole moments and the pulse width also have a prominent effect on the population transfer. By choosing appropriate values of the above parameters, complete population transfer can be realized.

  4. Snakes and ladders: Localized states in the Swift-Hohenberg equation

    Burke, John [Department of Physics, University of California, Berkeley, CA 94720 (United States)]. E-mail: burkej8@socrates.berkeley.edu; Knobloch, Edgar [Department of Physics, University of California, Berkeley, CA 94720 (United States)

    2007-01-15

    The Swift-Hohenberg equation with cubic and quintic nonlinearities exhibits multiple stable and unstable spatially localized states of arbitrary length in the vicinity of the Maxwell point between spatially homogeneous and periodic states. The even and odd states are organized in a characteristic snaking structure and are connected by branches of mixed parity states forming a ladder-like structure. Numerical computations are used to illustrate the changes in the localized solutions as they grow in spatial extent and to determine the stability and wavelength of the resulting states.

  5. OCCUPATIONAL SURVEY OF THE PREVENTIVE MEDICINE CAREER LADDER 907X0. VOLUME I.

    Preventive Medicine Career Ladder, and consisting of 275 tasks grouped under 16 duty categories, was administered to 381 airmen in 14 major air commands. Incumbents of all skill levels completed a background information section and rated on a 7-point scale relative time spent on tasks. The airmen also indicated on a 7-point scale amount of work experience on each task compared with other tasks performed. Job descriptions are presented for 32 groups selected according to background information variables. Included are 8 specialty groups, 10 groups with differing lengths

  6. Phase diagram of three-leg ladders at strong coupling along the rungs

    Kagan, Maxim Yu.; Haas, Stephan; Rice, T. M.

    1999-01-01

    A phase diagram of the t-J three-leg ladder as a function of hole dopping is derived in the limit where the coupling parameters along the rungs, $t_{\\perp}$ and $J_{\\perp}$, are taken to be much larger than those along the legs, $t_{||}$ and $J_{||}$ At large exchange coupling along the rungs, $J_{\\perp}/t_{\\perp}> 3 / \\sqrt{2}$, there is a transition from a low-dopping Luttinger liquid phase into a Luther-Emery liquid at a critical hole concentration $n_{crit}\\approx 1/3$. In the opposite ca...

  7. Coherent Phase Control of Multiphoton Ionization in Three-Level Ladder-Type System

    ZHANG Shi-An; CHEN Yu-Ting; WANG Zu-Geng; SUN Zhen-Rong

    2009-01-01

    We present the theoretical investigation of photoelectron spectroscopy resulting from the strong field induced multiphoton ionization in a typical three-level ladder-style system.Our theoretical results show that the photoelectron spectral structure can be alternatively steered by spectral phase modulation.This physical mechanism for strong field quantum control is explicitly exploited by the time-dependent dressed state population.It is concluded that the phase-shaped laser pulses can be used to selectively manipulate the multiphoton ionization process in complicated quantum systems.

  8. Magneto-optical polarization rotation in a ladder-type atomic system for tunable offset locking

    Parniak, Michał; Wasilewski, Wojciech

    2016-01-01

    We demonstrate an easily tunable locking scheme for stabilizing frequency-sum of two lasers on a two-photon ladder transition based on polarization rotation in warm rubidium vapors induced by magnetic field and circularly polarized driving field. In principle unlimited tunability of the two-photon offset frequency is due to strong splitting and shifting of magnetic states in external field. We achieve two-photon detuning of 120 MHz with the single-photon detuning of up to 20 GHz, as well as strong rotation signal.

  9. Magnetic dilution in the cadmium-doped spin ladder compound Cdx Cu1 - x (quinoxaline) Br2

    Keith, Brian; Landee, Chris; Turnbull, Mark

    2011-03-01

    Both Cu (quinoxaline) (Br2) and Cu (quinoxaline) (Cl2) are examples of molecule-based magnets where the CuX4 dimers are linked into ladders by quinoxaline molecules, where X is either Cl or Br. The rung exchange occurs through the bridging halides while the rail exchange occurs through the quinoxaline rings. Introducing random rung interactions into the system [ Cu (quinoxaline) (Br2)1-x (Cl2)x ] has caused the spin gap to close, in contrast with the gapped pure spin ladder parents. Crystal growth of non-magnetic-doped molecular magnets, CdxCu1 - x (2 , 3 - dimethylpyrazine)Br2 , have been performed for several values of the nominal conentration, x, and have been confirmed. The magnetizations and susceptibilities of the magnetically diluted ladder assemblage are presented along with a comparison of the effects of dilution from the pure case (x=0).

  10. Spin gap and string order parameter in the ferromagnetic spiral staircase heisenberg ladder: a quantum Monte Carlo study.

    Brünger, C; Assaad, F F; Capponi, S; Alet, F; Aristov, D N; Kiselev, M N

    2008-01-11

    We consider a spin-1/2 ladder with a ferromagnetic rung coupling J perpendicular and inequivalent chains. This model is obtained by a twist (theta) deformation of the ladder and interpolates between the isotropic ladder (theta=0) and the SU(2) ferromagnetic Kondo necklace model (theta = pi). We show that the ground state in the (theta, J perpendicular) plane has a finite string order parameter characterizing the Haldane phase. Twisting the chain introduces a new energy scale, which we interpret in terms of a Suhl-Nakamura interaction. As a consequence we observe a crossover in the scaling of the spin gap at weak coupling from delta/J parallel proportional, variant J perpendicular/J parallel for theta theta c. Those results are obtained on the basis of large scale quantum Monte Carlo calculations.

  11. Implementability of two-qubit unitary operations over the butterfly network and the ladder network with free classical communication

    Akibue, Seiseki [Department of Physics, Graduate School of Science, The University of Tokyo, Tokyo (Japan); Murao, Mio [Department of Physics, Graduate School of Science, The University of Tokyo, Tokyo, Japan and NanoQuine, The University of Tokyo, Tokyo (Japan)

    2014-12-04

    We investigate distributed implementation of two-qubit unitary operations over two primitive networks, the butterfly network and the ladder network, as a first step to apply network coding for quantum computation. By classifying two-qubit unitary operations in terms of the Kraus-Cirac number, the number of non-zero parameters describing the global part of two-qubit unitary operations, we analyze which class of two-qubit unitary operations is implementable over these networks with free classical communication. For the butterfly network, we show that two classes of two-qubit unitary operations, which contain all Clifford, controlled-unitary and matchgate operations, are implementable over the network. For the ladder network, we show that two-qubit unitary operations are implementable over the network if and only if their Kraus-Cirac number do not exceed the number of the bridges of the ladder.

  12. Multi-mode traffic-induced vibrations in composite ladder-deck bridges under heavy moving vehicles

    Camara, A.; Ruiz-Teran, A. M.

    2015-10-01

    Composite (steel-concrete) ladder-decks represent one of the most common solutions in road bridges nowadays. In these structures the Serviceability Limit State (SLS) of vibrations is traditionally ignored or roughly addressed by means of simple static deflection-based approaches, inherently assuming that the vibrations are controlled by the fundamental longitudinal mode. This work demonstrates that a wide range of high-order vibrational modes, involving the transverse flexure of the slab between longitudinal girders, govern the accelerations recorded in the deck and inside the vehicles. In addition, a new methodology for analysing the Vehicle-Bridge Interaction is proposed, including the approaching platforms, the transition slabs, and the bridge joints. The results suggest that the riding comfort for vehicle users is specially affected by direct effects on the wheels, like the road roughness and possible construction misalignments at the bridge joints, as well as low-frequency vibrations coming from the deck in short or slender bridges. The filtering effects resulting from the average of the response in time and in space when calculating the root mean square acceleration are also explored, and new design parameters are provided. In addition, several structural features (such as the depth and spacing of the longitudinal and transverse steel beams, the thickness of the concrete slab, and the stiffness of the cantilever cross beams at the diaphragm sections) have been studied, and a set of new design criteria has been established. It has been demonstrated that the transverse flexibility of the deck (specially influenced by the support conditions and the slab thickness) is critically important for the users' (pedestrians and vehicle passengers) comfort, as it controls the aforementioned high-order vibrational modes which govern the dynamic response.

  13. Variability of fish consumption within the 10 European countries participating in the European Investigation into Cancer and Nutrition (EPIC) study

    Welch, A.A.; Lund, E.; Amiano, P.;

    2002-01-01

    OBJECTIVE: To describe and compare the consumption of total fish (marine foods) and the fish sub-groups - white fish, fatty fish, very fatty fish, fish products and crustacea, in participants from the European Investigation into Cancer and Nutrition (EPIC) study. DESIGN: Cross-sectional analysis ...

  14. Programación de Controladores Lógicos (PLC) mediante Ladder y Lenguaje de Control Estructurado (SCL) en MATLAB

    2015-01-01

    Existen diferentes lenguajes de programación de Controladores Lógicos Programables (PLC), el más común de ellos es el lenguaje de programación gráfico para autómatas programables llamado LADDER. Sin embargo, el lenguaje LADDER no es amigable en programas que requieren de cálculos de ecuaciones matemáticas, por ejemplo, el cálculo del volumen de un tanque en un control de nivel. Lenguajes alternativos como el Lenguaje de Control Estructurado (SCL) son menos estudiados dada su complejidad y poc...

  15. A ladder network modelling the electrochemical impedance of the diffusion and reaction processes in semi-infinite space.

    Moya, A A

    2016-02-01

    The Gerischer impedance, i.e., the diffusion-reaction impedance of an ionic species in semi-infinite space, has been modelled by means of a novel simple equivalent ladder electric circuit constituted by a finite number of resistors and capacitors, which corresponds to the Cauer structure obtained from development into continued fractions. The Nyquist plots of the impedance of the ladder network or Cauer circuit and the deviation with respect to the Gerischer impedance have been originally analysed as a function of the number of circuit elements. From the Cauer equivalent circuit, a new and simple expression modelling the Gerischer impedance at the limit of the lowest frequencies has been derived.

  16. 0- and 2/3-magnetization plateaus in three-leg antiferromagnetic Heisenberg spin-1/2 ladders with leg-dimerization

    Li, Rui-Xue; Wang, Shu-Ling; Ni, Yun [School of Physics and Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan 430074 (China); Yao, Kai-Lun, E-mail: klyao@mail.hust.edu.cn [School of Physics and Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan 430074 (China); International Center of Materials Physics, Chinese Academy of Sciences, Shenyang 110015 (China); Fu, Hua-Hua [School of Physics and Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2014-02-01

    Magnetic properties of three-leg antiferromagnetic Heisenberg spin-1/2 ladders with different dimerization patterns have been studied using the bond mean-field theory. Our results show that rung-columnar ladders are thermodynamically stable states for large rung-to-leg coupling ratios. Magnetization curves of leg-columnar and leg-staggered ladders always exhibit 0- and 2/3-magnetization plateaus, which do not appear in rung-columnar and rung-staggered ladders. In leg-dimerized ladders, the formation of spin dimers in the three legs results in the appearance of the 0- and 2/3-magnetization plateaus. Spin configuration in the 2/3-magnetization plateau can be understood from the mean-field bond parameters.

  17. Optimization of Vibration Reduction Ability of Ladder Tracks by FEM Coupled with ACO

    Hao Jin

    2015-01-01

    Full Text Available Ladder track, which has drawn increased attention in scientific communities, is an effective method for reducing vibrations from underground railways. In order to optimize the vibration reduction ability of ladder track, a new method, that is, the finite element method (FEM coupled with ant colony optimization (ACO, has been proposed in this paper. We describe how to build the FEM model verified by the vibration tests in the Track Vibration Abatement and Control Laboratory and how to couple the FEM with ACO. The density and elasticity modulus of the sleeper pad are optimized using this method. After optimization, the vibration acceleration level of the supporting platform in the 1–200 Hz range was reduced from 102.8 dB to 94.4 dB. The optimized density of the sleeper pad is 620 kg/m3, and the optimized elasticity modulus of the sleeper pad is 6.25 × 106 N/m2.

  18. Energy-efficient hydrogen separation by AB-type ladder-polymer molecular sieves

    Ghanem, Bader

    2014-07-19

    The synthesis, microstructures, and exceptional gas transport properties of two new soluble ladder polymers, polymers of intrinsic microporosity (TPIM-1 and TPIM-2) containing triptycene moieties substituted with branched isopropyl and linear propyl chains at the 9,10-bridgeheads were reported. The precursor A-B monomers were modified with an o -difluoride functionality for enhanced activation for nucleophilic aromatic substitution. In a Schlenk tube, a mixture of the A-B monomer, 18-crown-6, anhydrous DMF and anhydrous potassium carbonate was stirred at 155 °C under nitrogen atmosphere for 20 min followed by the addition of toluene. The reaction was continued for another 45 min and more toluene was added. After another 45 min the reaction mixture was cooled to room temperature and poured into methanol. Slow evaporation of filtered, dilute 3-5 wt% chloroform solutions from a leveled glass plate yielded isotropic polymer films. Dry membranes were soaked in methanol for 24 h, air-dried, and then heated at 120°C for 24 h under high vacuum to remove any traces of residual solvent. TPIM-1 exhibits simultaneous boosts in permeability and selectivity, which highlights the significant potential of an isopropyl-substituted triptycene moiety as a contortion center for ladder PIMs.

  19. Quantum Magnetism of Spin-Ladder Compounds with Trapped-Ion Crystals

    Bermudez, A; Ott, K; Kaufmann, H; Ulm, S; Schmidt-Kaler, F; Retzker, A; Plenio, M B

    2012-01-01

    The quest for experimental platforms that allow for the exploration, and even control, of the interplay of low dimensionality and frustration is a fundamental challenge in several fields of quantum many-body physics, such as quantum magnetism. Here, we propose the use of cold crystals of trapped ions to study a variety of frustrated quantum spin ladders. By optimizing the trap geometry, we show how to tailor the low dimensionality of the models by changing the number of legs of the ladders. Combined with a method for selectively hiding of ions provided by laser addressing, it becomes possible to synthesize stripes of both triangular and Kagome lattices. Besides, the degree of frustration of the phonon-mediated spin interactions can be controlled by shaping the trap frequencies. We support our theoretical considerations by initial experiments with planar ion crystals, where a high and tunable anisotropy of the radial trap frequencies is demonstrated. We take into account an extensive list of possible error sou...

  20. GT1_abenz_1: Completing the OH ladder for HH 46

    Benz, A.

    2010-03-01

    First results from PACS observations towards the low-mass protostar HH 46 show surprisingly bright OH lines. The hydroxyl radical OH plays important roles in the water and oxygen chemistry of star-forming regions and their cooling. Furthermore, the hydroxyl-to-water line ratios are interesting tracers for ionizing radiation. We propose a nearly complete observation of the OH ladder in low-mass star formation for the first time. Four OH transitions in the class I object HH 46 were detected by PACS. We propose complementary observations towards the source in PACS line spectroscopy mode at 53, 56, 65, 71, 96, 115 and 135 micron. We gain insight in the origin and formation of OH from the PACS spatial information. The completeness of the OH ladder allows a reliable determination of the OH abundance and thus constrains water chemistry and cooling contribution more precisely. In addition, we propose HIFI observations of the OH transition at 163.4 micron to resolve the three hyperfine components for the first time. This will allow to determine optical depths of OH and test the hypothesis of asymmetries between the two closely spaced triplets, as the second triplet will be observed within the HIFI priority science program. Note: This proposal is submitted under the Swiss part of the HIFI guaranteed time program; HIFI PI: Frank Helmich, HIFI Swiss Lead CoI: Arnold O. Benz

  1. Fabrication of nanochannels with ladder nanostructure at the bottom using AFM nanoscratching method

    Yan, Yongda; Geng, Yanquan; Hu, Zhenjiang; Zhao, Xuesen; Yu, Bowen; Zhang, Qi

    2014-05-01

    This letter presents a novel atomic force microscopy (AFM)-based nanomanufacturing method combining the tip scanning with the high-precision stage movement to fabricate nanochannels with ladder nanostructure at the bottom by continuous scanning with a fixed scan size. Different structures can be obtained according to the matching relation of the tip feeding velocity and the precision stage moving velocity. This relationship was first studied in detail to achieve nanochannels with different ladder nanostructures at the bottom. Machining experiments were then performed to fabricate nanochannels on an aluminum alloy surface to demonstrate the capability of this AFM-based fabrication method presented in this study. Results show that the feed value and the tip orientation in the removing action play important roles in this method which has a significant effect on the machined surfaces. Finally, the capacity of this method to fabricate a large-scale nanochannel was also demonstrated. This method has the potential to advance the existing AFM tip-based nanomanufacturing technique of the formation these complex structures by increasing the removal speed, simplifying the processing procedure and achieving the large-scale nanofabrication.

  2. Ladder Oligo(m-aniline)s: Derivatives of Azaacenes with Cross-Conjugated [pi]-Systems

    Rajca, Andrzej; Boraty; #324; ski, Przemys; #322; aw J.; Olankitwanit, Arnon; Shiraishi, Kouichi; Pink, Maren; Rajca, Suchada (UNL); (Indiana)

    2012-04-30

    We describe the synthesis and electronic properties of ladder oligomers of poly(m-aniline) that may be considered as derivatives of azaacenes with cross-conjugated {pi}-systems. Syntheses of ladder oligo(m-aniline)s with 9 and 13 collinearly fused six-membered rings employed Pd-catalyzed aminations and Friedel-Crafts-based ring closures. Structures were confirmed by either X-ray crystallography or correlations between DFT-computed and experimental spectroscopic data such as {sup 1}H, {sup 13}C, and {sup 15}N NMR chemical shifts and electronic absorption spectra. All compounds have planar 'azaacene' moieties. The experimental band gaps E{sub g} {approx} 3.5-3.65 eV, determined by the UV-vis absorption onsets, were in agreement with the TD-DFT-computed vertical excitation energies to the S{sub 1} state. Fluorescence quantum yields of up to 20% were found. Electrochemically estimated HOMO energies of -4.8 eV suggested propensity for a facile one-electron oxidation and just sufficient environmental stability toward oxygen (O{sub 2}). For two oligomers with 'tetraazanonacene' moieties, potentials of E{sup 4+/3+} {approx} 1.6-1.7 V vs SCE were determined for four-electron oxidation to the corresponding tetraradical tetracations.

  3. Fishing amplifies forage fish population collapses.

    Essington, Timothy E; Moriarty, Pamela E; Froehlich, Halley E; Hodgson, Emma E; Koehn, Laura E; Oken, Kiva L; Siple, Margaret C; Stawitz, Christine C

    2015-05-26

    Forage fish support the largest fisheries in the world but also play key roles in marine food webs by transferring energy from plankton to upper trophic-level predators, such as large fish, seabirds, and marine mammals. Fishing can, thereby, have far reaching consequences on marine food webs unless safeguards are in place to avoid depleting forage fish to dangerously low levels, where dependent predators are most vulnerable. However, disentangling the contributions of fishing vs. natural processes on population dynamics has been difficult because of the sensitivity of these stocks to environmental conditions. Here, we overcome this difficulty by collating population time series for forage fish populations that account for nearly two-thirds of global catch of forage fish to identify the fingerprint of fisheries on their population dynamics. Forage fish population collapses shared a set of common and unique characteristics: high fishing pressure for several years before collapse, a sharp drop in natural population productivity, and a lagged response to reduce fishing pressure. Lagged response to natural productivity declines can sharply amplify the magnitude of naturally occurring population fluctuations. Finally, we show that the magnitude and frequency of collapses are greater than expected from natural productivity characteristics and therefore, likely attributed to fishing. The durations of collapses, however, were not different from those expected based on natural productivity shifts. A risk-based management scheme that reduces fishing when populations become scarce would protect forage fish and their predators from collapse with little effect on long-term average catches.

  4. Sport Fishing Regulations

    US Fish and Wildlife Service, Department of the Interior — The regulations for sport fishing on St. Vincent National Wildlife Refuge are outlined in this document. Fishing is only permitted from sunrise to sunset, and only...

  5. Fish Springs pond snail

    US Fish and Wildlife Service, Department of the Interior — Communication scenario between the branch of Listing and Recovery, Fish and Wildlife Enhancement, and Fish Springs National Wildlife Refuge (NWR), in regards to the...

  6. Fish tapeworm infection

    Fish tapeworm infection is an intestinal infection with the tapeworm parasite found in fish. ... The fish tapeworm ( Diphyllobothrium latum ) is the largest parasite that infects humans. Humans become infected when they eat raw ...

  7. Got a Sick Fish?

    ... Welfare Veterinary Careers Public Health Got a sick fish? Fish with disease can show a variety of signs. If you notice your pet fish having any unusual disease signs, contact your veterinarian ...

  8. 16 CFR 1207.5 - Design.

    2010-01-01

    ...) of this section. (b) Edges. Edges of swimming pool slide runways, ladders, handrails, and deck anchor... SWIMMING POOL SLIDES § 1207.5 Design. (a) Strength. The strength of the assembled and installed swimming pool slide shall be such that no structural failures of any component part shall cause failures of...

  9. No Fishing Now,More Fish Later

    2011-01-01

    Fishing ban for ecological purposes starts on the Pearl River Since April1,a two-month ban on fishing has been imposed on the Pearl River valley in south China.It is the first fishing ban in this area with the purpose of preserving biodiversity in China’s third longest

  10. Microbiological spoilage of fish and fish products

    Gram, Lone; Huss, Hans Henrik

    1996-01-01

    Spoilage of fresh and lightly preserved fish products is caused by microbial action. This paper reviews the current knowledge in terms of the microbiology of fish and fish products with particular emphasis on identification of specific spoilage bacteria and the qualitative and quantitative...

  11. Construction of a library of cloned short tandem repeat (STR) alleles as universal templates for allelic ladder preparation.

    Wang, Le; Zhao, Xing-Chun; Ye, Jian; Liu, Jin-Jie; Chen, Ting; Bai, Xue; Zhang, Jian; Ou, Yuan; Hu, Lan; Jiang, Bo-Wei; Wang, Feng

    2014-09-01

    Short tandem repeat (STR) genotyping methods are widely used for human identity testing applications, including forensic DNA analysis. Samples of DNA containing the length-variant STR alleles are typically separated and genotyped by comparison to an allelic ladder. Here, we describe a newly devised library of cloned STR alleles. The library covers alleles X and Y for the sex-determining locus Amelogenin and 259 other alleles for 22 autosomal STR loci (TPOX, D3S1358, FGA, D5S818, CSF1PO, D7S820, D8S1179, TH01, vWA, D13S317, D16S539, D18S51, D21S11, D2S1338, D6S1043, D12S391, Penta E, D19S433, D11S4463, D17S974, D3S4529 and D12ATA63). New primers were designed for all these loci to construct recombinant plasmids so that the library retains core repeat elements of STR as well as 5'- and 3'-flanking sequences of ∼500 base pairs. Since amplicons of commercial STR genotyping kits and systems developed in laboratories are usually distributed from 50 to STR alleles. The sequencing results showed all repeat structures we obtained for TPOX, CSF1PO, D7S820, TH01, D16S539, D18S51 and Penta E were the same as reported. However, we identified 102 unreported repeat structures from the other 15 STR loci, supplementing our current knowledge of repeat structures and leading to further understanding of these widely used loci.

  12. Hydrokinetic turbine effects on fish swimming behaviour.

    Linus Hammar

    Full Text Available Hydrokinetic turbines, targeting the kinetic energy of fast-flowing currents, are under development with some turbines already deployed at ocean sites around the world. It remains virtually unknown as to how these technologies affect fish, and rotor collisions have been postulated as a major concern. In this study the effects of a vertical axis hydrokinetic rotor with rotational speeds up to 70 rpm were tested on the swimming patterns of naturally occurring fish in a subtropical tidal channel. Fish movements were recorded with and without the rotor in place. Results showed that no fish collided with the rotor and only a few specimens passed through rotor blades. Overall, fish reduced their movements through the area when the rotor was present. This deterrent effect on fish increased with current speed. Fish that passed the rotor avoided the near-field, about 0.3 m from the rotor for benthic reef fish. Large predatory fish were particularly cautious of the rotor and never moved closer than 1.7 m in current speeds above 0.6 ms(-1. The effects of the rotor differed among taxa and feeding guilds and it is suggested that fish boldness and body shape influenced responses. In conclusion, the tested hydrokinetic turbine rotor proved non-hazardous to fish during the investigated conditions. However, the results indicate that arrays comprising multiple turbines may restrict fish movements, particularly for large species, with possible effects on habitat connectivity if migration routes are exploited. Arrays of the investigated turbine type and comparable systems should therefore be designed with gaps of several metres width to allow large fish to pass through. In combination with further research the insights from this study can be used for guiding the design of hydrokinetic turbine arrays where needed, so preventing ecological impacts.

  13. From fishing to fish processing: Separation of fish from crustaceans in the Norway lobster-directed multispecies trawl fishery improves seafood quality

    Karlsen, Junita Diana; Krag, Ludvig Ahm; Albertsen, Christoffer Moesgaard;

    2015-01-01

    Fishing gears have negative impacts on seafood quality, especially on fish in the mixed trawl fishery targeting Norway lobster (Nephrops norvegicus). In this fishery, which is worth about €80 millions in Denmark alone, the quality of fish can be significantly improved by simple gear changes....... A trawl codend divided into an upper and lower codend was designed to separate fish from Norway lobster during the fishing process by encourage fish to swim into the upper codend by using a frame at the entrance of the lower codend. Separate codends for fish and Norway lobster in the same gear provide...... the opportunity to selectively reduce small low-value fish, which will reduce catch weight and sorting time onboard the vessel. For this horizontally divided test codend and a standard codend, in which the catch was mixed, quality assessments were performed on the same batches of fish during three steps...

  14. Field-controlled magnetic order in the quantum spin-ladder system (Hpip)2CuBr4

    Thielemann, B.; Rüegg, C.; Kiefer, K.

    2009-01-01

    Neutron diffraction is used to investigate the field-induced, antiferromagnetically ordered state in the two-leg spin-ladder material (Hpip)(2)CuBr4. This "classical" phase, a consequence of weak interladder coupling, is nevertheless highly unconventional: its properties are influenced strongly b...

  15. Effect of vacuum-induced coherence on lasing without inversion in an equispaced three-level ladder system

    Jun Qian; Chengpu Liu; Shangqing Gong

    2005-01-01

    The effects of vacuum-induced coherence (VIC) on the properties of the absorption and gain of the probe field in an equispaced three-level ladder atomic system are investigated. It is found that lasing without inversion (LWI) is remarkably enhanced due to the effect of VIC in the case of the small incoherent pump rate.

  16. To Reach the First Rung and Higher: Building Healthcare Career Ladder Opportunities for Low-Skilled, Disadvantaged Adults

    Chisman, Forrest P.; Spangenberg, Gail

    2005-01-01

    This paper is based on various Council for Advancement of Adult Literacy (CAAL) activities including in-depth review of six exemplary career ladder programs offered in various institutional settings: a union, a hospital, a community-based organization (CBO), and three community colleges in partnership with an array of medical centers. The programs…

  17. Transition from Jaynes-Cummings to Autler-Townes ladder in a quantum dot-microcavity system

    Hopfmann, Caspar; Carmele, Alexander; Musiał, Anna; Schneider, Christian; Kamp, Martin; Höfling, Sven; Knorr, Andreas; Reitzenstein, Stephan

    2017-01-01

    We study experimentally and theoretically a coherently driven strongly coupled quantum dot-microcavity system. Our focus is on physics of the unexplored intermediate excitation regime where the resonant laser field dresses a strongly coupled single exciton-photon (polariton) system resulting in a ladder of laser-dressed Jaynes-Cummings states. In that case, both the coupling of the emitter to the confined light field of the microcavity and to the light field of the external laser are equally important, as proved by observation of injection pulling of the polariton branches by an external laser. This intermediate interaction regime is of particular interest since it connects the purely quantum mechanical Jaynes-Cummings ladder and the semiclassical Autler-Townes ladder. Exploring the driving strength dependence of the mutually coupled system we establish the maximum in the resonance fluorescence signal to be a robust fingerprint of the intermediate regime and observe signatures indicating the laser-dressed Jaynes-Cummings ladder. In order to address the underlying physics we excite the coupled system via the matter component of fermionic nature undergoing saturation—in contrast to commonly used cavity-mediated excitation.

  18. M(o)bius梯形图的亏格分布%Genus Distributions of M(o)bius Ladders

    李德明

    2005-01-01

    The genus distribution of a graph is a polynomial whose coefficients are the partition of the number of embeddings with respect to the genera. In this paper,the genus distribution of Mobius ladders is provided which is an infinite class of 3-connected simple graphs.

  19. Duration of pregnancy in relation to fish oil supplementation and habitual fish intake: a randomised clinical trial with fish oil

    Olsen, SF; Østerdal, ML; Salvig, JD;

    2007-01-01

    OBJECTIVE: To examine the effect of fish oil supplementation on duration of pregnancy, conditional on the woman's habitual fish intake. DESIGN: Multicentre 1:1 randomised clinical trial of effect of fish oil in a high-risk population of pregnant women in whom habitual fish intake was assessed...... at randomisation. SETTING: Nineteen university delivery wards in seven European countries. SUBJECTS: Pregnant women with preterm delivery, intrauterine growth retardation (IUGR), or pregnancy-induced hypertension (PIH) in a previous pregnancy (group 1, n=495); with twin pregnancies (group 2, n=367......); or with suspicion of IUGR or threatening preeclampsia in the current pregnancy (group 3, n=106). Women were stratified into low, middle, or high fish consumers. METHODS: The intervention group received fish oil capsules providing 2.7 g long-chain n-3 fatty acids per day (n-3 poly unsaturated fatty acids (PUFA...

  20. Duration of pregnancy in relation to fish oil supplementation and habitual fish intake: a randomised clinical trial with fish oil

    Olsen, Sjurdur Frodi; Østerdal, M L; Salvig, J D;

    2007-01-01

    at randomisation. SETTING: Nineteen university delivery wards in seven European countries. SUBJECTS: Pregnant women with preterm delivery, intrauterine growth retardation (IUGR), or pregnancy-induced hypertension (PIH) in a previous pregnancy (group 1, n=495); with twin pregnancies (group 2, n=367......OBJECTIVE: To examine the effect of fish oil supplementation on duration of pregnancy, conditional on the woman's habitual fish intake. DESIGN: Multicentre 1:1 randomised clinical trial of effect of fish oil in a high-risk population of pregnant women in whom habitual fish intake was assessed......); or with suspicion of IUGR or threatening preeclampsia in the current pregnancy (group 3, n=106). Women were stratified into low, middle, or high fish consumers. METHODS: The intervention group received fish oil capsules providing 2.7 g long-chain n-3 fatty acids per day (n-3 poly unsaturated fatty acids (PUFA...

  1. Design of Fuel Consumption Monitoring System for Fishing Vessels Based on STM 32%基于 STM32的渔船油耗监测系统设计

    杨郑明; 徐轶群

    2016-01-01

    Considering the fuel consumption of fishing vessels is too high as well as the inconvenience for fishery supervision department of a large number of fishing vessels , the function of the Internet of wireless communication technology is used to de-signed the fishing vessels fuel consumption monitoring system based on STM 32.The system consists of a monitoring center com-puter, a fuel consumption data acquisition gateway , a wireless transmission module and an inductive flow meter .Using ZigBee CC2530F256 chip as the core module , it can realize the function of all port network interconnection .By using the ZigBee coordi-nator and distribution on the fishing boat ZigBee router connected to the Internet , the system can realize acquisition and transmis-sion of the fishing vessel fuel consumption data , and data analysis and storage by the STM 32F207Z master control chip .Through the experiment of a certain port in Fuzhou , the real-time data acquisition and supervision department of the fishing vessel oil con -sumption is realized .%针对渔船燃油消耗过高以及渔业监管部门对大量渔船监管不便的问题,利用物联网无线通信技术的功能,设计基于STM32的渔船油耗监测系统,系统由监测中心计算机、油耗数据采集网关、无线传透模块和感应式流量计构成。利用CC2530F256芯片为核心的ZigBee模块,实现全港口网络互联的功能。下行通过ZigBee协调器与分布在渔船上的ZigBee路由器联网,实现渔船油耗数据的采集与传输,经由油耗数据采集网关主控芯片STM32F207Z进行数据的解析与存储,上行通过RS232实现与监测计算机的通讯。在福州某港口试验证明,可实现渔船油耗实时数据采集和监管部门对渔船的远程监测。

  2. Plastic fish

    Antonella Del Rosso

    2015-01-01

    In terms of weight, the plastic pollution in the world’s oceans is estimated to be around 300,000 tonnes. This plastic comes from both land-based and ocean-based sources. A lecture at CERN by chemist Wolfgang Trettnak addressed this issue and highlighted the role of art in raising people’s awareness.   Artwork by Wolfgang Trettnak. Packaging materials, consumer goods (shoes, kids’ toys, etc.), leftovers from fishing and aquaculture activities… our oceans and beaches are full of plastic litter. Most of the debris from beaches is plastic bottles. “PET bottles have high durability and stability,” explains Wolfgang Trettnak, a chemist by education and artist from Austria, who gave a lecture on this topic organised by the Staff Association at CERN on 26 May. “PET degrades very slowly and the estimated lifetime of a bottle is 450 years.” In addition to the beach litter accumulated from human use, rivers bring several ki...

  3. Enhancing fish performance in Aquaculture

    Aquaculture currently is the fastest growing agricultural industry and must continue to grow to meet the world’s increasing demand for seafood. Continued growth will depend upon advances in fish genetics and nutrition, and improvements in culture system design and management. The number and complexi...

  4. Consumer perceptions of farmed fish

    Reinders, Machiel J.; Banović, Marija; Guerrero, Lluis; Krystallis, Athanasios

    2016-01-01

    Purpose – The purpose of this paper is to investigate possible cross-cultural consumer segments
    in the EU aquaculture market and provide direction and focus for marketing strategies for farmed
    fish products.
    Design/methodology/approach – Selected psychographic constructs (i.e. category i

  5. Hybrid seine for full fish community collections

    McKenna, James E.; Waldt, Emily M.; Abbett, Ross; David, Anthony; Snyder, James

    2013-01-01

    Seines are simple and effective fish collection gears, but the net mesh size influences how well the catch represents the fish communities. We designed and tested a hybrid seine with a dual-mesh bag (1/4″ and 1/8″) and compared the fish assemblage collected by each mesh. The fine-mesh net retained three times as many fish and collected more species (as many as eight), including representatives of several rare species, than did the coarser mesh. The dual-mesh bag permitted us to compare both sizes and species retained by each layer and to develop species-specific abundance correction factors, which allowed comparison of catches with the coarse-mesh seine used for earlier collections. The results indicate that a hybrid seine with coarse-mesh wings and a fine-mesh bag would enhance future studies of fish communities, especially when small-bodied fishes or early life stages are the research focus.

  6. Trichromatic π-Pulse for Ultrafast Total Inversion of a Four-Level Ladder System

    Carles Serrat

    2015-11-01

    Full Text Available We present a numerical solution for complete population inversion in a four-level ladder system obtained by using a full π-pulse illumination scheme with resonant ultrashort phase-locked Gaussian laser pulses. We find that a set of pulse areas such as √3π , √2π , and √3π completely inverts the four-level system considering identical effective dipole coupling coefficients. The solution is consistent provided the involved electric fields are not too strong and it is amply accurate also in the case of diverse transition dipole moments. We study the effect of detuning and chirp of the laser pulses on the complete population inversion using the level structure of atomic sodium interacting with ps and fs pulses as an example. Our result opens the door for multiple applications such as efficient ultrashort pulse lasing in the UV or the engineering of quantum states for quantum computing.

  7. A renormalization approach to describe charge transport in quasiperiodic dangling backbone ladder (DBL)-DNA molecules

    Sarmento, R.G. [Departamento de Fisica, Universidade Federal do Rio Grande do Norte, 59072-970 Natal, RN (Brazil); Fulco, U.L. [Departamento de Biofisica e Farmacologia, Universidade Federal do Rio Grande do Norte, 59072-970 Natal, RN (Brazil); Albuquerque, E.L., E-mail: eudenilson@gmail.com [Departamento de Biofisica e Farmacologia, Universidade Federal do Rio Grande do Norte, 59072-970 Natal, RN (Brazil); Caetano, E.W.S. [Instituto Federal de Educacao, Ciencia e Tecnologia do Ceara, 60040-531 Fortaleza, CE (Brazil); Freire, V.N. [Departamento de Fisica, Universidade Federal do Ceara, 60455-760 Fortaleza, CE (Brazil)

    2011-10-31

    Highlights: → One-step renormalization approach to describe the DBL-DNA molecule. → Electronic tight-binding Hamiltonian model. → A quasiperiodic sequence to mimic the DNA nucleotides arrangement. → Electronic transmission spectra. → I-V characteristics. -- Abstract: We study the charge transport properties of a dangling backbone ladder (DBL)-DNA molecule focusing on a quasiperiodic arrangement of its constituent nucleotides forming a Rudin-Shapiro (RS) and Fibonacci (FB) Poly (CG) sequences, as well as a natural DNA sequence (Ch22) for the sake of comparison. Making use of a one-step renormalization process, the DBL-DNA molecule is modeled in terms of a one-dimensional tight-binding Hamiltonian to investigate its transmissivity and current-voltage (I-V) profiles. Beyond the semiconductor I-V characteristics, a striking similarity between the electronic transport properties of the RS quasiperiodic structure and the natural DNA sequence was found.

  8. Vibrational ladder-climbing in surface-enhanced, ultrafast infrared spectroscopy.

    Kraack, Jan Philip; Hamm, Peter

    2016-06-28

    In a recent work (J. Phys. Chem. C 2016, 120, 3350-3359), we have introduced the concept of surface-enhanced, two-dimensional attenuated total reflectance (2D ATR IR) spectroscopy with modest enhancement factors (450), which allows for multi-quantum IR excitation of adsorbed molecules, a process known as "vibrational ladder-climbing", even for weakly absorbing (ε < 200 M(-1) cm(-1)) nitrile IR labels. We show that it is possible to deposit up to four quanta of vibrational energy in the respective functional group. Based on these results, optical near-fields of plasmonic nanostructures may pave the way for future investigations involving ultrafast dynamics of highly excited vibrational states or surface-sensitive coherent control experiments of ground-state reactions at solid-liquid interfaces.

  9. Coherence generation and population transfer in a three-level ladder system

    Zhang Bing; Jiang Yun; Wang Gang; Zhang Li-Da; Wu Jin-Hui; Gao Jin-Yue

    2011-01-01

    This work explores the effect of spontaneous emission on coherence generation and population transfer in a threelevel ladder atomic system driven by two pulses in counterintuitive order. With adiabatic evolution and the weakdephasing approximation, we find that a large coherence and population transfer can be achieved even with spontaneous decay rate. The maximum coherence and population transfer decrease with the increase of spontaneous decay rate from the highest state to intermediate state. But this effect can be compensated by shortening the pulse width and enlarging the delay time. Results show that the coherence generation and population transfer never depend on the spontaneous decay rate from the intermediate state to ground state. The validity of the analytic solution is examined by numerical calculation.

  10. Radiation pressure and laser cooling of a three-level atom in a ladder configuration

    Tan Lei; Wang Zhi-Cheng; Gu Huai-Qiang

    2004-01-01

    Radiation pressure and laser cooling of a moving three-level ladder-type atom in bichromatic travelling fields are considered. The dependence of the force on parameters such as detunings, Rabi frequencies and spontaneous decay rates is calculated numerically and shown graphically, and analytical expressions for the force are obtained for some special parameter values. It is shown that the radiation pressure shows Doppler-shifted resonance peaks resulting respectively from one-photon and two-photon transitions. Using the present scheme, Doppler cooling of sodium exploiting the 3 2S1/2-3 2P3/2-3 2D5/2 cascade transitions is investigated. It is found that temperatures lower than the Doppler limit can be achieved.

  11. ROMANIA: CLIMBING THE LADDER FOR A BETTER FUTURE. WHEN WILL IT REACH EU AND EURO AREA?

    Cristina Tatomir

    2011-12-01

    Full Text Available In this paper we assess the evolution of Romania’s economic convergence with the European Union (EU and Euro area, during the period 2000-2010. In order to determine the number of years required to reach the EU and Euro area average, we employ an economic convergence index, made up of real and structural convergence indexes. The analysis shows that Romania has been climbing the ladder in the process of catching-up with the EU and the Euro area until 2008 when, because of the international crisis, the economic convergence index started decreasing. We report that Romania will reach the EU average in April 2056 and the Euro area average in September 2062.As revealed by the analysis, it will take decadesto attain the European levels of economic convergence, this being the most important challenge for Romania on the long term.

  12. Tunable hybridization at midzone and anomalous Bloch-Zener oscillations in optical waveguide ladders.

    Zheng, Ming Jie; Wang, Gang; Yu, Kin Wah

    2010-12-01

    We have studied the optical oscillation and tunneling of light waves in optical waveguide ladders (OWLs) formed by two coupled planar optical waveguide arrays. For the band structure, a midzone gap is formed owing to band hybridization, and its wavenumber position can be tuned throughout the whole Brillouin zone, which is different from the Bragg gap. By imposing a gradient in the propagation constant in each array, Bloch-Zener oscillation (BZO) is realized with Zener tunneling between the bands occurring at the midzone, which is contrary to the common BZO with tunneling at the center or edge of the Brillouin zone. The occurrence of BZO is demonstrated by using the field-evolution analysis. The tunable hybridization at the midzone enhances the tunability of BZO in the OWLs. This Letter may offer new insights into the coherent phenomena in optical lattices.

  13. Calculating Three Loop Ladder and V-Topologies for Massive Operator Matrix Elements by Computer Algebra

    Ablinger, J; Blümlein, J; De Freitas, A; von Manteuffel, A; Schneider, C

    2015-01-01

    Three loop ladder and $V$-topology diagrams contributing to the massive operator matrix element $A_{Qg}$ are calculated. The corresponding objects can all be expressed in terms of nested sums and recurrences depending on the Mellin variable $N$ and the dimensional parameter $\\varepsilon$. Given these representations, the desired Laurent series expansions in $\\varepsilon$ can be obtained with the help of our computer algebra toolbox. Here we rely on generalized hypergeometric functions and Mellin-Barnes representations, on difference ring algorithms for symbolic summation, on an optimized version of the multivariate Almkvist-Zeilberger algorithm for symbolic integration, and on new methods to calculate Laurent series solutions of coupled systems of differential equations. The solutions can be computed for general coefficient matrices directly for any basis also performing the expansion in the dimensional parameter in case it is expressible in terms of indefinite nested product-sum expressions. This structural ...

  14. Poisson equation for the three loop ladder diagram in string theory at genus one

    Basu, Anirban

    2016-01-01

    The three loop ladder diagram is a graph with six links and four cubic vertices that contributes to the D^{12} R^4 amplitude at genus one in type II string theory. The vertices represent the insertion points of vertex operators on the toroidal worldsheet and the links represent scalar Green functions connecting them. By using the properties of the Green function and manipulating the various expressions, we obtain a modular invariant Poisson equation satisfied by this diagram, with source terms involving one, two and three loop diagrams. Unlike the source terms in the Poisson equations for diagrams at lower orders in the momentum expansion or the Mercedes diagram, a particular source term involves a five point function containing a holomorphic and a antiholomorphic worldsheet derivative acting on different Green functions. We also obtain simple equalities between topologically distinct diagrams, and consider some elementary examples.

  15. Poisson equation for the three-loop ladder diagram in string theory at genus one

    Basu, Anirban

    2016-11-01

    The three-loop ladder diagram is a graph with six links and four cubic vertices that contributes to the D12ℛ4 amplitude at genus one in type II string theory. The vertices represent the insertion points of vertex operators on the toroidal worldsheet and the links represent scalar Green functions connecting them. By using the properties of the Green function and manipulating the various expressions, we obtain a modular invariant Poisson equation satisfied by this diagram, with source terms involving one-, two- and three-loop diagrams. Unlike the source terms in the Poisson equations for diagrams at lower orders in the momentum expansion or the Mercedes diagram, a particular source term involves a five-point function containing a holomorphic and a antiholomorphic worldsheet derivative acting on different Green functions. We also obtain simple equalities between topologically distinct diagrams, and consider some elementary examples.

  16. Gadolinium(III)-hydroxy ladders trapped in succinate frameworks with optimized magnetocaloric effect.

    Chen, Yan-Cong; Guo, Fu-Sheng; Zheng, Yan-Zhen; Liu, Jun-Liang; Leng, Ji-Dong; Tarasenko, Róbert; Orendáč, Martin; Prokleška, Jan; Sechovský, Vladimír; Tong, Ming-Liang

    2013-09-27

    Two kinds of inorganic gadolinium(III)-hydroxy "ladders", [2×n] and [3×n], were successfully trapped in succinate (suc) coordination polymers, [Gd2(OH)2(suc)2(H2O)]n·2nH2O (1) and [Gd6(OH)8(suc)5(H2O)2 ]n·4n H2O (2), respectively. Such coordination polymers could be regarded as alternating inorganic-organic hybrid materials with relatively high density. Magnetic and heat capacity studies reveal a large cryogenic magnetocaloric effect (MCE) in both compounds, namely (ΔH=70 kG) 42.8 J kg(-1) K(-1) for complex 1 and 48.0 J kg(-1) K(-1) for complex 2. The effect of the high density is evident, which gives very large volumetric MCEs up to 120 and 144 mJ cm(-3) K(-1) for complexes 1 and 2, respectively.

  17. Comments on Formulating Meson Bound-State Equations Beyond Rainbow-Ladder Approximation

    Qin, Si-xue

    2016-11-01

    We study mesons through solving the coupled system of the gap equation for the quark propagator and the Bethe-Salpeter equation for the meson wavefunction. The gap equation and Bethe-Salpeter equation are in fact members of infinitely coupled Dyson-Schwinger equations of Green functions of QCD. To make it solvable, the system must be truncated. The simplest rainbow-ladder truncation is widely used but shows drawbacks in many aspects. To improve the simplest truncation, we analyze symmetries of the fundamental theory and solve the corresponding Ward-Green-Takahashi identities. Then, the elements of the coupled system, i.e., the quark-gluon vertex and the quark-antiquark scattering kernel, can be constructed accordingly.

  18. A renormalization approach to describe charge transport in quasiperiodic dangling backbone ladder (DBL)-DNA molecules

    Sarmento, R. G.; Fulco, U. L.; Albuquerque, E. L.; Caetano, E. W. S.; Freire, V. N.

    2011-10-01

    We study the charge transport properties of a dangling backbone ladder (DBL)-DNA molecule focusing on a quasiperiodic arrangement of its constituent nucleotides forming a Rudin-Shapiro (RS) and Fibonacci (FB) Poly (CG) sequences, as well as a natural DNA sequence (Ch22) for the sake of comparison. Making use of a one-step renormalization process, the DBL-DNA molecule is modeled in terms of a one-dimensional tight-binding Hamiltonian to investigate its transmissivity and current-voltage (I-V) profiles. Beyond the semiconductor I-V characteristics, a striking similarity between the electronic transport properties of the RS quasiperiodic structure and the natural DNA sequence was found.

  19. Vlasov Simulations of Ladder Climbing and Autoresonant Acceleration of Langmuir Waves

    Hara, Kentaro; Barth, Ido; Kaminski, Erez; Dodin, Ilya; Fisch, Nathaniel

    2016-10-01

    The energy of plasma waves can be moved up and down the spectrum using chirped modulations of plasma parameters, which can be driven by external fields. Depending on the discreteness of the wave spectrum, this phenomenon is called ladder climbing (LC) or autroresonant acceleration (AR) of plasmons, and was first proposed by Barth et al. based on a linear fluid model. Here, we report a demonstration of LC/AR from first principles using fully nonlinear Vlasov simulations of collisionless bounded plasma. We show that, in agreement to the basic theory, plasmons survive substantial transformations of the spectrum and are destroyed only when their wave numbers become large enough to trigger Landau damping. The work was supported by the NNSA SSAA Program through DOE Research Grant No. DE-NA0002948 and the DTRA Grant No. HDTRA1-11-1-0037.

  20. Surprises from the resummation of ladders in the ABJ(M) cusp anomalous dimension

    Bonini, Marisa; Preti, Michelangelo; Seminara, Domenico

    2016-01-01

    We study the cusp anomalous dimension in N=6 ABJ(M) theory, identifying a scaling limit in which the ladder diagrams dominate. The resummation is encoded into a Bethe-Salpeter equation that is mapped to a Schroedinger problem, exactly solvable due to the surprising supersymmetry of the effective Hamiltonian. In the ABJ case the solution implies the diagonalization of the U(N) and U(M) building blocks, suggesting the existence of two independent cusp anomalous dimensions and an unexpected exponentiation structure for the related Wilson loops. While consistent with previous perturbative analysis, the strong coupling limit of our result does not agree with the string theory computation, emphasizing a difference with the analogous resummation in the N=4 case.

  1. Massive 3-loop ladder diagrams for quarkonic local operator matrix elements

    Ablinger, Jakob; Schneider, Carsten [Johannes Kepler Univ., Linz (Austria). Research Inst. for Symbolic Computation; Bluemlein, Johannes; Hasselhuhn, Alexander; Wissbrock, Fabian [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Klein, Sebastian [Technische Hochschule Aachen (Germany). Inst. fuer Theoretische Physik

    2012-06-15

    3-loop diagrams of the ladder-type, which emerge for local quarkonic twist-2 operator matrix elements, are computed directly for general values of the Mellin variable N using Appell-function representations and applying modern summation technologies provided by the package Sigma and the method of hyperlogarithms. In some of the diagrams generalized harmonic sums with {xi} element of {l_brace}1,1/2,2{r_brace} emerge beyond the usual nested harmonic sums. As the asymptotic representation of the corresponding integrals shows, the generalized sums conspire giving well behaved expressions for large values of N. These diagrams contribute to the 3-loop heavy flavor Wilson coefficients of the structure functions in deep-inelastic scattering in the region Q{sup 2} >> m{sup 2}.

  2. Study of a four-level system in vee + ladder configuration

    Bharti, Vineet

    2015-01-01

    We present the results of a theoretical study of a four-level atomic system in vee + ladder configuration using a density matrix analysis. The absorption and dispersion profiles are derived for a weak probe field and for varying strengths of the two strong control fields. For specificity, we choose energy levels of $^{87}$Rb, and present results for both stationary atoms and moving atoms in room temperature vapor. An electromagnetically induced absorption (EIA) peak with negative dispersion is observed at zero probe detuning when the control fields have equal strengths, which switches to electromagnetically induced transparency (EIT) with positive dispersion (due to splitting of the EIA peak) when the control fields are unequal. There is significant linewidth narrowing in thermal vapor.

  3. Three-loop master integrals for ladder-box diagrams with one massive leg

    Di Vita, Stefano; Schubert, Ulrich; Yundin, Valery

    2014-01-01

    The three-loop master integrals for ladder-box diagrams with one massive leg are computed from an eighty-five by eighty-five system of differential equations, solved by means of Magnus exponential. The results of the considered box-type integrals, as well as of the tower of vertex- and bubble-type master integrals associated to subtopologies, are given as a Taylor series expansion in the dimensional regulator parameter epsilon = (4-d)/2. The coefficients of the series are expressed in terms of uniform weight combinations of multiple polylogarithms and transcendental constants up to weight six. The considered integrals enter the next-to-next-to-next-to-leading order virtual corrections to scattering processes like the three-jet production mediated by vector boson decay, V* -> jjj, as well as the Higgs plus one-jet production in gluon fusion, pp -> Hj.

  4. Thinking about going to the dentist: a Contemplation Ladder to assess dentally-avoidant individuals' readiness to go to a dentist

    Hillstead M Blake

    2011-01-01

    Full Text Available Abstract Background The Transtheoretical Model suggests that individuals vary according to their readiness to change behavior. Previous work in smoking cessation and other health areas suggests that interventions are more successful when they are tailored to an individual's stage of change with regards to the specific behavior. We report on the performance of a single-item measure ("Ladder" to assess the readiness to change dental-avoidant behavior. Methods An existing Contemplation Ladder for assessing stage of change in smoking cessation was modified to assess readiness to go to a dentist. The resulting Ladder was administered to samples of English-speaking adolescents (USA, Spanish-speaking adults (USA, and Norwegian military recruits (Norway in order to assess construct validity. The Ladder was also administered to a sample of English-speaking avoidant adolescents and young adults who were enrolled in an intervention study (USA in order to assess criterion validity. All participants also had dental examinations, and completed other questionnaires. Correlations, chi square, t tests and one-way ANOVAs were used to assess relationships between variables. Results In two samples, participants who do not go to the dentist had significantly more teeth with caries; in a third sample, participants who do not go to the dentist had significantly worse caries. Ladder scores were not significantly related to age, gender, caries, or dental fear. However, Ladder scores were significantly related to statements of intention to visit a dentist in the future and the importance of oral health. In a preliminary finding, Ladder scores at baseline also predicted whether or not the participants decided to go to a dentist in the intervention sample. Conclusions The data provide support for the convergent and divergent construct validity of the Ladder, and preliminary support for its criterion validity. The lack of relationship between dental fear and Ladder scores

  5. Three Kinds of Fish

    Høst, Jeppe Engset

    2012-01-01

    There are three kinds of fish. Fish you were given, fish you bought and fish you lease. This might sound a bit odd, but it is nevertheless the basis for the activities of Danish commercial fishers since the introduction of transferable fishing concessions (TFCs) in 2007. In the current 2012 reform...... of market based systems are wild speculation, concentration and monopolization of fishing access and subsequent leasing with fishing communities and new entrants very likely being worse off (see for example the chapter “From fishing rights to financial derivatives” is this volume or Olson 2011; Sumaila 2010...... will examine five Danish fishing operations and discuss how they have reacted in different ways to the newly introduced system of transferable fishing concessions. By introducing TFCs as a solution to fleet overcapacity, the EU Commission will also be introducing a system where buying, selling and leasing...

  6. Cocaine is low on the value ladder of rats: possible evidence for resilience to addiction.

    Lauriane Cantin

    Full Text Available BACKGROUND: Assessing the relative value of cocaine and how it changes with chronic drug use represents a long-standing goal in addiction research. Surprisingly, recent experiments in rats--by far the most frequently used animal model in this field--suggest that the value of cocaine is lower than previously thought. METHODOLOGY/PRINCIPAL FINDINGS: Here we report a series of choice experiments that better define the relative position of cocaine on the value ladder of rats (i.e., preference rank-ordering of different rewards. Rats were allowed to choose either taking cocaine or drinking water sweetened with saccharin--a nondrug alternative that is not biologically essential. By systematically varying the cost and concentration of sweet water, we found that cocaine is low on the value ladder of the large majority of rats, near the lowest concentrations of sweet water. In addition, a retrospective analysis of all experiments over the past 5 years revealed that no matter how heavy was past cocaine use most rats readily give up cocaine use in favor of the nondrug alternative. Only a minority, fewer than 15% at the heaviest level of past cocaine use, continued to take cocaine, even when hungry and offered a natural sugar that could relieve their need of calories. CONCLUSIONS/SIGNIFICANCE: This pattern of results (cocaine abstinence in most rats; cocaine preference in few rats maps well onto the epidemiology of human cocaine addiction and suggests that only a minority of rats would be vulnerable to cocaine addiction while the large majority would be resilient despite extensive drug use. Resilience to drug addiction has long been suspected in humans but could not be firmly established, mostly because it is difficult to control retrospectively for differences in drug self-exposure and/or availability in human drug users. This conclusion has important implications for preclinical research on the neurobiology of cocaine addiction and for future medication

  7. Measurements of Saggings and Torsions of 1.15m Length Silicon Detector Ladder Supported by Lightweight Carbon Fibre Space Frame

    Alexandrov, V S; CERN. Geneva; Bolonin, A A; Vitushkin, L F

    1995-01-01

    Results of measurements of gravitational sagging and torsions of the first prototype of long Si-ladder for the outer (the largest) layer of the Inner Tracker System (ITS) of ALICE are reported for different ladder orientations and different loads (up to 80g). 47.9 µm sagging in the middle of the ladder for the horizontal orientation of Si-wafers appear to be in a satisfactory agreement with the preliminary finite element calculations. The linearity of deformation as a function of load was also studied.

  8. 36 CFR 2.3 - Fishing.

    2010-07-01

    ... statutory law. (5) Fishing by the use of drugs, poisons, explosives, or electricity. (6) Digging for bait... bridges, from or within 200 feet of a public raft or float designated for water sports, or within...

  9. FWS Special Designation Areas

    US Fish and Wildlife Service, Department of the Interior — This data layer depicts the Special Designations that have been placed upon the lands and waters administered by the U.S. Fish and Wildlife Service (USFWS) in North...

  10. Multiplex-FISH (M-FISH): technique, developments and applications.

    Kearney, L

    2006-01-01

    Multiplex FISH (M-FISH) represents one of the most significant developments in molecular cytogenetics of the past decade. Originally designed to generate 24 colour karyotyping, the technique has spawned many variations and an equally diverse range of applications. In tumour and leukaemia cytogenetics, the two groups that have been targeted represent both ends of the cytogenetic spectrum: those with an apparently normal karyotype (suspected of harbouring small rearrangements not detectable by conventional cytogenetics) and those with a complex aberrant karyotype (which are difficult to karyotype accurately due to the sheer number of aberrations). In research, mouse M-FISH provides a powerful tool to characterize mouse models of a disease. In addition, the ability to accurately karyotype single metaphases without selection makes M-FISH the perfect tool in chromosome breakage studies and for characterizing clonal evolution of tumours. Finally, M-FISH has emerged as the perfect partner for the developing genomic microarray (array CGH) technologies, providing a powerful approach to gene discovery.

  11. Why don’t adolescents eat fish? Factors influencing fish consumption in school

    Prell, Hillevi; Berg, Christina; Jonsson, Lena

    2002-01-01

    Background: Theory-based research is needed to promote healthy eating in adolescents and to work out interventions. Objective: To examine what factors influence adolescents’ fish consumption in school. Design: A total of 162 pupils from the 8th grade (age º14 years) at two schools completed a questionnaire based on the Theory of Planned Behaviour. In 150 of these subjects, fish consumption was assessed by observation on four occasions. Results: Attitudes towards the fish, friends’ behaviour a...

  12. Randomized trial of weight-loss-diets for young adults varying in fish and fish oil content

    Thorsdottir, I.; Tomasson, H.; Gunnarsdottir, I.; Gisladottir, E.; Kiely, M.; Parra, M.D.; Bandarra, N.M.; Schaafsma, G.; Martinez, J.A.

    2007-01-01

    Objective: To investigate the effect of including seafood and fish oils, as part of an energy-restricted diet, on weight loss in young overweight adults. Design: Randomized controlled trial of energy-restricted diet varying in fish and fish oil content was followed for 8 weeks. Subjects were randomi

  13. Laboratory Studies on the Effects of Shear on Fish

    Neitzel, Duane A.; Richmond, Marshall C.; Dauble, Dennis D.; Mueller, Robert P.; Moursund, Russell A.; Abernethy, Cary S.; Guensch, Greg R.

    2000-09-20

    The overall objective of our studies was to specify an index describing the hydraulic force that fish experience when subjected to a shear environment. Fluid shear is a phenomenon that is important to fish. However, elevated levels of shear may result in strain rates that injure or kill fish. At hydroelectric generating facilities, concerns have been expressed that strain rates associated with passage through turbines, spillways, and fish bypass systems may adversely affect migrating fish. Development of fish friendly hydroelectric turbines requires knowledge of the physical forces (injury mechanisms) that impact entrained fish and the fish's tolerance to these forces. It requires up-front, pre-design specifications for the environmental conditions that occur within the turbine system, in other words, determining or assuming that those conditions known to injure fish will provide the descriptions of conditions that engineers must consider in the design of a turbine system. These biological specifications must be carefully and thoroughly documented throughout the design of a fish friendly turbine. To address the development of biological specifications, we designed and built a test facility where juvenile fish could be subjected to a range of shear environments and quantified their biological response.

  14. Walking on the Ladder: 125 GeV Technidilaton, or Conformal Higgs -Dedicated to the late Professor Yoichiro Nambu-

    Matsuzaki, Shinya

    2015-01-01

    The walking technicolor based on the ladder Schwinger-Dyson gap equation is studied, with the scale-invariant coupling being an idealization of the Caswell-Banks-Zaks infrared fixed point in the "anti-Veneziano limit", such that $N_C \\rightarrow \\infty$ with $N_C \\cdot \\alpha(\\mu^2)=$ fixed and $N_F/N_C=$ fixed ($\\gg 1$), of the $SU(N_C)$ gauge theory with massless $N_F$ flavors near criticality. We show that the 125 GeV Higgs can be naturally identified with the technidilaton (TD) predicted in the walking technicolor, a pseudo Nambu-Goldstone (NG) boson of the spontaneous symmetry breaking of the approximate scale symmetry. Ladder calculations yield the TD mass $M_\\phi$ from the trace anomaly as $M_\\phi^2 F_\\phi^2= -4 \\langle \\theta_\\mu^\\mu \\rangle = - \\frac{\\beta(\\alpha (\\mu^2))}{\\alpha(\\mu^2)}\\, \\langle G_{\\lambda \

  15. Environmental mitigation at hydroelectric projects. Volume 2, Benefits and costs of fish passage and protection

    Francfort, J.E.; Rinehart, B.N.; Sommers, G.L. [EG and G Idaho, Inc., Idaho Falls, ID (United States); Cada, G.F.; Jones, D.W. [Oak Ridge National Lab., TN (United States); Dauble, D.D. [Pacific Northwest Lab., Richland, WA (United States); Hunt, R.T. [Hunt (Richard) Associates, Inc., Concord, NH (United States); Costello, R.J. [Northwest Water Resources Advisory Services (United States)

    1994-01-01

    This study examines envirorunental mitigation practices that provide upstream and downstream fish passage and protection at hydroelectric projects. The study includes a survey of fish passage and protection mitigation practices at 1,825 hydroelectric plants regulated by the Federal Energy Regulatory Commission (FERC) to determine frequencies of occurrence, temporal trends, and regional practices based on FERC regions. The study also describes, in general terms, the fish passage/protection mitigation costs at 50 non-Federal hydroelectric projects. Sixteen case studies are used to examine in detail the benefits and costs of fish passage and protection. The 16 case studies include 15 FERC licensed or exempted hydroelectric projects and one Federally-owned and-operated hydroelectric project. The 16 hydroelectric projects are located in 12 states and range in capacity from 400 kilowatts to 840 megawatts. The fish passage and protection mitigation methods at the case studies include fish ladders and lifts, an Eicher screen, spill flows, airburst-cleaned inclined and cylindrical wedgewire screens, vertical barrier screens, and submerged traveling screens. The costs, benefits, monitoring methods, and operating characteristics of these and other mitigation methods used at the 16 case studies are examined.

  16. Umatilla - Rough Fish Eradication

    US Fish and Wildlife Service, Department of the Interior — In order to enhance environmental conditions in the McCormack Slough on Umatilla NWR, the population of rough fish, including common carp (Cyprinus carpio) and...

  17. Scorpion fish sting

    ... this page: //medlineplus.gov/ency/article/002849.htm Scorpion fish sting To use the sharing features on this page, please enable JavaScript. Scorpion fish are members of the family Scorpaenidae, which ...

  18. Pittsburgh Fish Fry Locations

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — Lenten Fish Fry records for the Greater Pittsburgh region. Data is collected before and during the Lenten fish fry season each year by Code for Pittsburgh. Data is...

  19. Star formation relations and CO spectral line energy distributions across the J-ladder and redshift

    Greve, T. R. [Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom); Leonidaki, I.; Xilouris, E. M. [Institute for Astronomy, Astrophysics, Space Applications and Remote Sensing, National Observatory of Athens, GR-15236 Penteli (Greece); Weiß, A.; Henkel, C. [Max-Planck-Institut fur Radioastronomie, Auf dem Hügel 69, D-53121 Bonn (Germany); Zhang, Z.-Y. [UK Astronomy Technology Centre, Science and Technology Facilities Council, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom); Van der Werf, P.; Meijerink, R. [Leiden Observatory, Leiden University, PO Box 9513, NL-2300 RA Leiden (Netherlands); Aalto, S. [Department of Earth and Space Sciences, Chalmers University of Technology, Onsala Observatory, 43994 Onsala (Sweden); Armus, L.; Díaz-Santos, T. [Spitzer Science Center, California Institute of Technology, MS 220-6, Pasadena, CA 91125 (United States); Evans, A. S. [Astronomy Department, University of Virginia Charlottesville, VA 22904 (United States); Fischer, J. [Naval Research Laboratory, Remote Sensing Division, 4555 Overlook Avenue SW, Washington, DC 20375 (United States); Gao, Y. [Purple Mountain Observatory, Chinese Academy of Sciences, 2 West Beijing Road, Nanjing 210008 (China); González-Alfonso, E. [Universidad de Alcala de Henares, Departamento de Fśica, Campus Universitario, E-28871 Alcalá de Henares, Madrid (Spain); Harris, A. [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); Naylor, D. A. [Institute for Space Imaging Science, Department of Physics and Astronomy, University of Lethbridge, Lethbridge, AB T1K 3M4 (Canada); Smith, H. A. [Harvard Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Spaans, M., E-mail: t.greve@ucl.ac.uk [Kapteyn Astronomical Institute, University of Groningen, PO Box 800, 9700 AV Groningen (Netherlands); and others

    2014-10-20

    We present FIR [50-300 μm]–CO luminosity relations (i.e., log L{sub FIR}=αlog L{sub CO}{sup ′}+β) for the full CO rotational ladder from J = 1-0 up to J = 13-12 for a sample of 62 local (z ≤ 0.1) (Ultra) Luminous Infrared Galaxies (LIRGs; L {sub IR[8-1000} {sub μm]} > 10{sup 11} L {sub ☉}) using data from Herschel SPIRE-FTS and ground-based telescopes. We extend our sample to high redshifts (z > 1) by including 35 submillimeter selected dusty star forming galaxies from the literature with robust CO observations, and sufficiently well-sampled FIR/submillimeter spectral energy distributions (SEDs), so that accurate FIR luminosities can be determined. The addition of luminous starbursts at high redshifts enlarge the range of the FIR–CO luminosity relations toward the high-IR-luminosity end, while also significantly increasing the small amount of mid-J/high-J CO line data (J = 5-4 and higher) that was available prior to Herschel. This new data set (both in terms of IR luminosity and J-ladder) reveals linear FIR–CO luminosity relations (i.e., α ≅ 1) for J = 1-0 up to J = 5-4, with a nearly constant normalization (β ∼ 2). In the simplest physical scenario, this is expected from the (also) linear FIR–(molecular line) relations recently found for the dense gas tracer lines (HCN and CS), as long as the dense gas mass fraction does not vary strongly within our (merger/starburst)-dominated sample. However, from J = 6-5 and up to the J = 13-12 transition, we find an increasingly sublinear slope and higher normalization constant with increasing J. We argue that these are caused by a warm (∼100 K) and dense (>10{sup 4} cm{sup –3}) gas component whose thermal state is unlikely to be maintained by star-formation-powered far-UV radiation fields (and thus is no longer directly tied to the star formation rate). We suggest that mechanical heating (e.g., supernova-driven turbulence and shocks), and not cosmic rays, is the more likely source of energy for

  20. Evaluating analytical approaches for estimating pelagic fish biomass using simulated fish communities

    Yule, Daniel L.; Adams, Jean V.; Warner, David M.; Hrabik, Thomas R.; Kocovsky, Patrick M.; Weidel, Brian C.; Rudstam, Lars G.; Sullivan, Patrick J.

    2013-01-01

    Pelagic fish assessments often combine large amounts of acoustic-based fish density data and limited midwater trawl information to estimate species-specific biomass density. We compared the accuracy of five apportionment methods for estimating pelagic fish biomass density using simulated communities with known fish numbers that mimic Lakes Superior, Michigan, and Ontario, representing a range of fish community complexities. Across all apportionment methods, the error in the estimated biomass generally declined with increasing effort, but methods that accounted for community composition changes with water column depth performed best. Correlations between trawl catch and the true species composition were highest when more fish were caught, highlighting the benefits of targeted trawling in locations of high fish density. Pelagic fish surveys should incorporate geographic and water column depth stratification in the survey design, use apportionment methods that account for species-specific depth differences, target midwater trawling effort in areas of high fish density, and include at least 15 midwater trawls. With relatively basic biological information, simulations of fish communities and sampling programs can optimize effort allocation and reduce error in biomass estimates.

  1. Using Echo Ultrasound from Schooling Fish to Detect and Classify Fish Types

    Yeffry Handoko; Yul.Y. Nazaruddin; Huosheng Hu

    2009-01-01

    Fish finders have already been widely available in the fishing market for a number of years. However, the sizes of these fish finders are too big and their prices are expensive to suit for the research of robotic fish or mini-submarine. The goal of this research is to propose a low-cost fish detector and classifier which suits for underwater robot or submarine as a proximity sensor .With some pre-condition in hardware and algorithms, the experimental results show that the proposed design has good per-formance, with a detection rate of 100 % and a classification rate of 94 %. Both the existing type of fish and the group behavior can be revealed by statistical interpretations such as hovering passion and sparse swimming mode.

  2. Programación de Controladores Lógicos (PLC mediante Ladder y Lenguaje de Control Estructurado (SCL en MATLAB

    Heyder David Páez-Logreira

    2015-05-01

    Full Text Available Existen diferentes lenguajes de programación de Controladores Lógicos Programables (PLC, el más común de ellos es el lenguaje de programación gráfico para autómatas programables llamado LADDER. Sin embargo, el lenguaje LADDER no es amigable en programas que requieren de cálculos de ecuaciones matemáticas, por ejemplo, el cálculo del volumen de un tanque en un control de nivel. Lenguajes alternativos como el Lenguaje de Control Estructurado (SCL son menos estudiados dada su complejidad y poca popularidad en la pequeña y mediana industria. En este artículo se compara los resultados del lenguaje de programación LADDER y el lenguaje SCL generado mediante la herramienta Simulink® PLC Coder de MATLAB® tomando como caso de estudio el cálculo de volumen de un tanque. Finalmente, este trabajo demuestra que la herramienta Simulink® PLC Coder presenta una alternativa de desarrollo más eficiente.

  3. Quantum Monte Carlo simulation of antiferromagnetic spin ladder (C5H12N)2CuBr4

    Freitas, Augusto S.

    2016-07-01

    In this paper I present a Quantum Monte Carlo (QMC) study of the magnetic properties of an antiferromagnetic spin ladder (C5H12N)2CuBr4. This compound is the prototype of the Heisenberg model for a two leg spin ladder in the presence of an external magnetic field. The susceptibility phase diagram has a rounded peak in the vicinity of T=7.4 K, obeys Troyer's law for low temperatures, and Curie's law for high temperatures. I also study the susceptibility diagram in low temperatures and I found the spin gap Δ=9.26 K, in good concordance with the experimental value, 9.5 K. In high field, I present a diagram of magnetization as a function of temperature. In the vicinity of a critical field, Hci, the magnetization scales with T1/2 and this result was found also in the QMC simulation. In all the results, there is a very good concordance with the experimental data. I also show in this paper that the spin gap is null and the susceptibility is proportional to T for low temperatures when relatively high values of the ladders' coupling is taken in account.

  4. Pressure-induced superconductivity in the iron-based ladder material BaFe2S3.

    Takahashi, Hiroki; Sugimoto, Akira; Nambu, Yusuke; Yamauchi, Touru; Hirata, Yasuyuki; Kawakami, Takateru; Avdeev, Maxim; Matsubayashi, Kazuyuki; Du, Fei; Kawashima, Chizuru; Soeda, Hideto; Nakano, Satoshi; Uwatoko, Yoshiya; Ueda, Yutaka; Sato, Taku J; Ohgushi, Kenya

    2015-10-01

    All the iron-based superconductors identified so far share a square lattice composed of Fe atoms as a common feature, despite having different crystal structures. In copper-based materials, the superconducting phase emerges not only in square-lattice structures but also in ladder structures. Yet iron-based superconductors without a square-lattice motif have not been found, despite being actively sought out. Here, we report the discovery of pressure-induced superconductivity in the iron-based spin-ladder material BaFe2S3, a Mott insulator with striped-type magnetic ordering below ∼120 K. On the application of pressure this compound exhibits a metal-insulator transition at about 11 GPa, followed by the appearance of superconductivity below Tc = 14 K, right after the onset of the metallic phase. Our findings indicate that iron-based ladder compounds represent promising material platforms, in particular for studying the fundamentals of iron-based superconductivity.

  5. 49 CFR 173.218 - Fish meal or fish scrap.

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Fish meal or fish scrap. 173.218 Section 173.218... Fish meal or fish scrap. (a) Except as provided in Column (7) of the HMT in § 172.101 of this subchapter, fish meal or fish scrap, containing at least 6%, but not more than 12% water, is authorized...

  6. Medusivorous fishes, a review

    Ates, R.M.L.

    1988-01-01

    A preliminary review is presented of fish species having consumed pelagic Cnidaria (Scyphozoa and Hydrozoa) as well as Ctenophora. Quantitative data are scarce. Knowledge of morphological and physiological adaptations of fishes foraging on gelatinous plankton is almost non-existent. Many fish specie

  7. Medusivorous fishes, a review

    Ates, R.M.L.

    1988-01-01

    A preliminary review is presented of fish species having consumed pelagic Cnidaria (Scyphozoa and Hydrozoa) as well as Ctenophora. Quantitative data are scarce. Knowledge of morphological and physiological adaptations of fishes foraging on gelatinous plankton is almost non-existent. Many fish species consume medusae and some reasons to suspect that there are even more that do so, are discussed.

  8. Motives, barriers and quality evaluation in fish consumption situations

    Brunsø, Karen; Verbeke, Wim; Olsen, Svein Ottar

    2009-01-01

    though fish consumption levels differ considerably. The main motives for eating fish are health and taste, while the main barriers are price perception, smell when cooking fish, and that fish does not deliver the same level of satiety as compared to meat. Big differences are found between countries....../implications - This study is based on qualitative focus group discussions in two European countries only. Originality/value - This study explores and compares motives, barriers and quality evaluation among heavy and light fish consumers in two European countries. The paper yields valuable insights for further quantitative......Purpose - The purpose of this paper is to investigate motives and barriers for eating fish among light users and heavy users, to discuss consumer evaluation of fish quality, and to explore the existence of cross-cultural fish consumer  segments. Design/methodology/approach - Qualitative data were...

  9. Transport properties of poly(GACT)–poly(CTGA) deoxyribonucleic acid: A ladder model approach

    S A Ketabi; A A Fouladi

    2009-06-01

    In this paper, based on the tight-binding Hamiltonian model and within the framework of a generalized Green's function technique, the electronic conduction through the poly(GACT)–poly(CTGA) DNA molecule in SWNT/DNA/SWNT structure has been numerically investigated. In a ladder model, we consider DNA as a planar molecule containing cells and four further sites (two base pair sites and two backbone sites) in each cell, sandwiched between two semi-infinite single-walled carbon nanotubes (SWNT) as the electrodes. Having relied on Landauer formalism, we focussed on studying the current–voltage characteristics of DNA, the effect of the coupling strength of SWNT/DNA interface and the role of tube radius of nanotube contacts on the electronic transmission through the foregoing structure. Finally, a characteristic time was calculated for the electron transmission, which measures the delay caused by the tunnelling through the SWNT/DNA interface. The results clearly show that the calculated characteristic time and also the conductance of the system are sensitive to the coupling strength between DNA molecule and nanotube contacts.

  10. Wire and extended ladder model predict THz oscillations in DNA monomers, dimers and trimers

    Lambropoulos, K; Morphis, A; Tassi, M; Lopp, R; Georgiadis, G; Theodorakou, M; Chatzieleftheriou, M; Simserides, C

    2016-01-01

    We call \\textit{monomer} a B-DNA base pair and study, analytically and numerically, electron or hole oscillations in \\textit{monomers}, \\textit{dimers} and \\textit{trimers}. We employ two Tight Binding (TB) approaches: (I) at the base-pair level, using the on-site energies of the base pairs and the hopping parameters between successive base pairs i.e. \\textit{a wire model}, and (II) at the single-base level, using the on-site energies of the bases and the hopping parameters between neighbouring bases, specifically between (a) two successive bases in the same strand, (b) complementary bases that define a base pair, and (c) diagonally located bases of successive base pairs, i.e. \\textit{an extended ladder model} since it also includes the diagonal hoppings (c). For \\textit{monomers}, with TB II, we predict periodic carrier oscillations with frequency $f \\approx$ 50-550 THz. For \\textit{dimers}, with TB I, we predict periodic carrier oscillations with $f \\approx$ 0.25-100 THz. For \\textit{trimers made of identic...

  11. SYNTHESIS AND CHARACTERIZATION OF AMINO FUNCTIONALIZED LADDER-LIKE POLYSILSESQUIOXANES AND THEIR HYBRID FILMS WITH POLYIMIDE

    Qiu-shuang Gao; Guo-feng Tian; Sheng-li Qi; Zhan-peng Wu; De-zhen Wu

    2013-01-01

    Ladder-like polysilsesquioxanes (LPSQs) with different amino contents have been synthesized by controlling of the dosage of Pd/C catalyst.The concentration and activity of amino groups were investigated by Fourier transform infrared spectroscopy.Polyimide (PI)/LPSQ hybrid films have been prepared by incorporating of the obtained LPSQs with different amino contents into PI matrix,respectively.The interfacial interactions between PI matrix and LPSQ were studied with scanning electron microscopy and X-ray photoelectron spectroscopy,meanwhile the thermal and mechanical properties of the hybrid films were studied using dynamic mechanical analysis and tensile tests.The results indicate that the functionality of LPSQ has great effects on the interfacial interactions and the properties of hybrid films.With the increase of amino content,both the interracial interactions and the cross-linking density of hybrids enhanced,which results in the decline of surface silicon concentration,increase of Young's modulus and drop of elongation at break.Excessive amino content makes the hybrid films brittle and leads to incomplete imidization.

  12. Cerebral ischemia produces laddered DNA fragments distinct from cardiac ischemia and archetypal apoptosis.

    MacManus, J P; Fliss, H; Preston, E; Rasquinha, I; Tuor, U

    1999-05-01

    The electrophoretic pattern of laddered DNA fragments which has been observed after cerebral ischemia is considered to indicate that neurons are dying by apoptosis. Herein the authors directly demonstrate using ligation-mediated polymerase chain reaction methods that 99% of the DNA fragments produced after either global or focal ischemia in adult rats, or produced after hypoxia-ischemia in neonatal rats, have staggered ends with a 3' recess of approximately 8 to 10 nucleotides. This is in contrast to archetypal apoptosis in which the DNA fragments are blunt ended as seen during developmental programmed cell death in dying cortical neurons, neuroblastoma, or thymic lymphocytes. It is not simply ischemia that results in staggered ends in DNA fragments because ischemic myocardium is similar to archetypal apoptosis with a vast majority of blunt-ended fragments. It is concluded that the endonucleases that produce this staggered fragmentation of the DNA backbone in ischemic brain must be different than those of classic or type I apoptosis.

  13. Calculating three loop ladder and V-topologies for massive operator matrix elements by computer algebra

    Ablinger, J.; Behring, A.; Blümlein, J.; De Freitas, A.; von Manteuffel, A.; Schneider, C.

    2016-05-01

    Three loop ladder and V-topology diagrams contributing to the massive operator matrix element AQg are calculated. The corresponding objects can all be expressed in terms of nested sums and recurrences depending on the Mellin variable N and the dimensional parameter ε. Given these representations, the desired Laurent series expansions in ε can be obtained with the help of our computer algebra toolbox. Here we rely on generalized hypergeometric functions and Mellin-Barnes representations, on difference ring algorithms for symbolic summation, on an optimized version of the multivariate Almkvist-Zeilberger algorithm for symbolic integration, and on new methods to calculate Laurent series solutions of coupled systems of differential equations. The solutions can be computed for general coefficient matrices directly for any basis also performing the expansion in the dimensional parameter in case it is expressible in terms of indefinite nested product-sum expressions. This structural result is based on new results of our difference ring theory. In the cases discussed we deal with iterative sum- and integral-solutions over general alphabets. The final results are expressed in terms of special sums, forming quasi-shuffle algebras, such as nested harmonic sums, generalized harmonic sums, and nested binomially weighted (cyclotomic) sums. Analytic continuations to complex values of N are possible through the recursion relations obeyed by these quantities and their analytic asymptotic expansions. The latter lead to a host of new constants beyond the multiple zeta values, the infinite generalized harmonic and cyclotomic sums in the case of V-topologies.

  14. Topological phase transition in a ladder of the dimerized Kitaev superconductor chains

    Zhou, Bo-Zhen; Zhou, Bin

    2016-10-01

    We investigate the topological properties of a ladder model of the dimerized Kitaev superconductor chains. The topological class of the system is determined by the relative phase θ between the inter- and intra-chain superconducting pairing. One topological class is the class BDI characterized by the ℤ index, and the other is the class D characterized by the ℤ2 index. For the two different topological classes, the topological phase diagrams of the system are presented by calculating two different topological numbers, i.e., the ℤ index winding number W and the ℤ2 index Majorana number ℳ, respectively. In the case of θ =0, the topological class belongs to the class BDI, multiple topological phase transitions accompanying the variation of the number of Majorana zero modes are observed. In the case of θ =π/2 it belongs to the class D. Our results show that for the given value of dimerization, the topologically nontrivial and trivial phases alternate with the variation of chemical potential. Project supported by the National Natural Science Foundation of China (Grant No. 11274102), the Program for New Century Excellent Talents in University of Ministry of Education of China (Grant No. NCET-11-0960), and the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20134208110001).

  15. Climbing the Jaynes-Cummings ladder and observing its nonlinearity in a cavity QED system.

    Fink, J M; Göppl, M; Baur, M; Bianchetti, R; Leek, P J; Blais, A; Wallraff, A

    2008-07-17

    The field of cavity quantum electrodynamics (QED), traditionally studied in atomic systems, has gained new momentum by recent reports of quantum optical experiments with solid-state semiconducting and superconducting systems. In cavity QED, the observation of the vacuum Rabi mode splitting is used to investigate the nature of matter-light interaction at a quantum-mechanical level. However, this effect can, at least in principle, be explained classically as the normal mode splitting of two coupled linear oscillators. It has been suggested that an observation of the scaling of the resonant atom-photon coupling strength in the Jaynes-Cummings energy ladder with the square root of photon number n is sufficient to prove that the system is quantum mechanical in nature. Here we report a direct spectroscopic observation of this characteristic quantum nonlinearity. Measuring the photonic degree of freedom of the coupled system, our measurements provide unambiguous spectroscopic evidence for the quantum nature of the resonant atom-field interaction in cavity QED. We explore atom-photon superposition states involving up to two photons, using a spectroscopic pump and probe technique. The experiments have been performed in a circuit QED set-up, in which very strong coupling is realized by the large dipole coupling strength and the long coherence time of a superconducting qubit embedded in a high-quality on-chip microwave cavity. Circuit QED systems also provide a natural quantum interface between flying qubits (photons) and stationary qubits for applications in quantum information processing and communication.

  16. Laddering: Revelando a Coleta e Interpretação dos Dados

    Ana Akemi Ikeda

    2014-09-01

    Full Text Available Laddering é uma técnica de pesquisa bastante apropriada quando o foco está relacionado ao entendimento do valor para o cliente e valores pessoais. Trata-se de uma técnica de entrevista individual e profunda que se ampara na análise de conteúdo para desenvolver conhecimento sobre como os indivíduos traduzem os atributos de produtos em associações significativas em relação a si mesmo seguindo a teoria meios-fim, ou seja, atributos que levam a consequências e que culminam com os valores dos entrevistados. Apesar de oportuna em estudos de marketing, por investigar o comportamento humano, o restrito número de publicações sobre sua aplicação prática podem desestimular os pesquisadores de utilizá-la. Assim, o presente estudo tem por objetivo à luz da atividade de marketing discutir a técnica e descrever as principais etapas da pesquisa (entrevista, coleta de dados e análise. A descrição desse processo foi feita a partir de uma pesquisa real que utilizou a técnica. Constata-se que mesmo exploratória, a pesquisa que se utiliza desta técnica disponibiliza informações valiosas para suporte nas decisões em marketing. 

  17. NMR study on the quasi one-dimensional quantum spin magnet with ladder structure

    Kobori, Shohei; Matsui, Kazuki; Kuwahara, Hideki; Goto, Takayuki; Zhang, Xiao; Nakano, Yuki; Nishihara, Sadafumi; Inoue, Katsuya; Sasaki, Takahiko

    2016-12-01

    The two-legged spin ladder Cu(CO3)0.5(ClO4)(H2O)0.5(NH3)2.5 consists of a rung formed by two Cu(II)'s and of a spacing molecule CO3^{2-} between each two rungs. The non-centrosymmetric shape of CO3^{2-} molecule brings a slight bond alternation along the leg, and hence the system can be considered as an alternating spin chain, which is confirmed so far by the temperature dependence of magnetic susceptibility. In order to investigate its spin state at low temperatures, we have performed experiments of 1H-NMR, magnetization and specific heat under wide range of magnetic field, and have found the critical diverging of longitudinal relaxation rate 1/ T 1, the spectral broadening and the lambda-type anomaly in specific heat at T N≃ 3.4 K, indicating the existence of long range magnetic order. In paramagnetic state well above T N, 1/ T 1 showed a power-law temperature dependence, suggesting the realization of Tomonaga Luttinger liquid state.

  18. Automated Translation of Safety Critical Application Software Specifications into PLC Ladder Logic

    Leucht, Kurt W.; Semmel, Glenn S.

    2008-01-01

    The numerous benefits of automatic application code generation are widely accepted within the software engineering community. A few of these benefits include raising the abstraction level of application programming, shorter product development time, lower maintenance costs, and increased code quality and consistency. Surprisingly, code generation concepts have not yet found wide acceptance and use in the field of programmable logic controller (PLC) software development. Software engineers at the NASA Kennedy Space Center (KSC) recognized the need for PLC code generation while developing their new ground checkout and launch processing system. They developed a process and a prototype software tool that automatically translates a high-level representation or specification of safety critical application software into ladder logic that executes on a PLC. This process and tool are expected to increase the reliability of the PLC code over that which is written manually, and may even lower life-cycle costs and shorten the development schedule of the new control system at KSC. This paper examines the problem domain and discusses the process and software tool that were prototyped by the KSC software engineers.

  19. On the cusp anomalous dimension in the ladder limit of $\\mathcal N=4$ SYM

    Beccaria, Matteo; Macorini, Guido

    2016-01-01

    We analyze the cusp anomalous dimension in the (leading) ladder limit of $\\mathcal N=4$ SYM and present new results for its higher-order perturbative expansion. We study two different limits with respect to the cusp angle $\\phi$. The first is the light-like regime where $x = e^{i\\,\\phi}\\to 0$. This limit is characterised by a non-trivial expansion of the cusp anomaly as a sum of powers of $\\log x$, where the maximum exponent increases with the loop order. The coefficients of this expansion have remarkable transcendentality features and can be expressed by products of single zeta values. We show that the whole logarithmic expansion is fully captured by a solvable Woods-Saxon like one-dimensional potential. From the exact solution, we extract generating functions for the cusp anomaly as well as for the various specific transcendental structures appearing therein. The second limit that we discuss is the regime of small cusp angle. In this somewhat simpler case, we show how to organise the quantum mechanical pert...

  20. Mott transition in a two-leg Bose-Hubbard ladder under an artificial magnetic field

    Keleş, Ahmet; Oktel, M. Ö.

    2015-01-01

    We consider the Bose-Hubbard model on a two-leg ladder under an artificial magnetic field and investigate the superfluid-to-Mott insulator transition in this setting. Recently, this system has been experimentally realized [M. Atala et al., Nature Phys. 10, 588 (2014), 10.1038/nphys2998], albeit in a parameter regime that is far from the Mott transition boundary. Depending on the strength of the magnetic field, the single-particle spectrum has either a single ground state or two degenerate ground states. The transition between these two phases is reflected in the many-particle properties. We first investigate these phases through the Bogoliubov approximation in the superfluid regime and calculate the transition boundary for weak interactions. For stronger interactions the system is expected to form a Mott insulator. We calculate the Mott transition boundary as a function of the magnetic field and interleg coupling with mean-field theory, strong-coupling expansion, and density matrix renormalization group (DMRG). Finally, using the DMRG, we investigate the particle-hole excitation gaps of this system at different filling factors and find peaks at simple fractions, indicating the possibility of correlated phases.

  1. Effects of relative phase on transient evolution in an open resonant ladder-type atomic system

    Yang Yan-Ling; Liu Zhong-Bo; Wang Lei; Tong Dian-Min; Fan Xi-Jun

    2009-01-01

    In an open ladder-type resonant atomic system, variation in relative phase between probe and driving fields does not affect the transient evolution of populations, but it has remarkable effects on gain and dispersion of the probe field. No matter whether an incoherent pump is present or absent, transient and stationary gains without inversion (GWI) always can be obtained by choosing an appropriate value of the relative phase. When the incoherent pump is absent, the values of transient and stationary GWIs are much larger and the time interval required to reach the stationary value is longer than those when the incoherent pump is present. Varying the exit rate and the ratio between injection rates can obviously change the phase-dependent GWI. In addition, in the transient evolution process, the phenomenon of high dispersion (refractive index) without absorption occurs at some values of relative phase. In the corresponding closed system, the stationary GWI can be obtained by choosing an appropriate value of relative phase only when incoherent pump exists, moreover the gain is smaller than that in the open system.

  2. Noise property of a four-level system in vee + ladder configuration

    Ming, Ying; Liu, Hong-Yu; Yang, Rong-Can

    2016-11-01

    We present the results of a theoretical study of the output amplitude noises of a four-level atomic system in vee + ladder configuration. The difference and connection of electromagnetically induced transparency and Autler-Townes splitting effects are investigated theoretically. The output amplitude noise of the probe field of two effects were compared, the quantum properties of the input field of the thin medium and the thick medium under Autler-Townes splitting or electromagnetically induced transparency (EIT) condition are maintained, the higher fidelity is obtained in the storage of the thick medium under the condition of EIT in non-classical states. The noise characteristics of the squeezed vacuum field after four-level coherent medium are studied; the noise of the output field is lowest when the detection light is far away from detuning. The double split of EIT window was made by the dynamic Stark splitting on the ground state of control field, the quantum properties of the input field in the strong-control field and strong-coupling field were maintained. The output noise spectrum is divided with the increase in the field strength, the maximum output squeezing is far away from the resonance.

  3. Fully frustrated Josephson junction ladders with Mobius boundary conditions as topologically protected qubits

    Cristofano, Gerardo; Marotta, Vincenzo [Dipartimento di Scienze Fisiche, Universita di Napoli ' Federico II' and INFN, Sezione di Napoli, Via Cintia, Complesso Universitario M. Sant' Angelo, 80126 Napoli (Italy); Naddeo, Adele [Dipartimento di Fisica ' E.R. Caianiello' , Universita degli Studi di Salerno and CNISM, Unita di Ricerca di Salerno, Via Salvador Allende, 84081 Baronissi (Saudi Arabia) (Italy)], E-mail: naddeo@sa.infn.it; Niccoli, Giuliano [LPTM, Universite de Cergy-Pontoise, 2 avenue Adolphe Chauvin, 95302 Cergy-Pontoise (France)

    2008-03-31

    We show how to realize a 'protected' qubit by using a fully frustrated Josephson junction ladder (JJL) with Mobius boundary conditions. Such a system has been recently studied within a twisted conformal field theory (CFT) approach [G. Cristofano, G. Maiella, V. Marotta, Mod. Phys. Lett. A 15 (2000) 1679; G. Cristofano, G. Maiella, V. Marotta, G. Niccoli, Nucl. Phys. B 641 (2002) 547] and shown to develop the phenomenon of flux fractionalization [G. Cristofano, V. Marotta, A. Naddeo, G. Niccoli, Eur. Phys. J. B 49 (2006) 83]. The relevance of a 'closed' geometry has been fully exploited in relating the topological properties of the ground state of the system to the presence of half flux quanta and the emergence of a topological order has been predicted [G. Cristofano, V. Marotta, A. Naddeo, J. Stat. Mech.: Theory Exp. (2005) P03006]. In this Letter the stability and transformation properties of the ground states under adiabatic magnetic flux change are analyzed and the deep consequences on the realization of a solid state qubit, protected from decoherence, are presented.

  4. Instructional ladders in computer networks practicums%计算机网络实践课程的阶梯式教学法

    刘春波; 钟安鸣; 顾兆军

    2012-01-01

    尽管大力加强了计算机网络实践教学的人力和物力投入,但教学效果却难以尽如人意.经分析,学生基础不一、接受能力不同是重要原因.阶梯式教学法则可以有效地解决这个问题.它将一个复杂的、高级的教学目标分解为从低级到高级、难度逐渐增大的多个目标,使得终极目标对于每一个学生都是可以实现的.在计算机网络实践课程中,依据教学目标,将网络协议分析和网络应用编程两个模块的教学分别划分为三级阶梯.教学实践表明,在教学目标有所提高的情况下,能够较好实现目标的学生比例从1/2提高到2/3.%Despite a great deal of human and material resources have been devoted to computer network practical teaching, teaching effect is difficult to satisfactory. It is found that students have different basis and different accept capacities is an important cause. Laddered teaching method can effectively solve this problem. It breaks down a complex advanced teaching objective into multiple targets whose difficulty increases gradually from lower to higher so that the ultimate goal can be achieved for each student. In computer networks practicums, teaching processes of network protocol analyzing module and network application programming module are both designed as three-stair ladders according to the teaching objectives. Teaching practices show that in the case of enhanced teaching objective, the proportion of students who can well achieve the objective increases from 1/2 to 2/3.

  5. Design

    Volf, Mette

    This publication is unique in its demystification and operationalization of the complex and elusive nature of the design process. The publication portrays the designer’s daily work and the creative process, which the designer is a part of. Apart from displaying the designer’s work methods...... and design parameters, the publication shows examples from renowned Danish design firms. Through these examples the reader gets an insight into the designer’s reality....

  6. Do Fish Resist?

    Dinesh Joseph Wadiwel

    2016-03-01

    Full Text Available There have been a number of scientific studies on the question of whether fish feel pain. Some have suggested that some fish indeed do feel pain and that this has significant welfare implications (2003. Others have argued that fish do not have the brain development necessary to feel pain. In terms of number of animals killed, the slaughter of sea animals for human consumption significantly exceeds that of any land animals that we use for food, and sea animal slaughter practices frequently lack any basic welfare protections. If fish can be shown to feel pain—or more importantly, if humans can agree that fish feel pain—then this would place a significant question mark over many contemporary fishing practices.  This article substitutes the question 'Do Fish Feel Pain?' with an alternative: 'Do Fish Resist?' It explores the conceptual problems of understanding fish resistance, and the politics of epistemology that surrounds and seeks to develop a conceptual framework for understanding fish resistance to human capture by exploring the development of fishing technologies - the hook, the net and contemporary aquaculture.

  7. Fish allergy: in review.

    Sharp, Michael F; Lopata, Andreas L

    2014-06-01

    Globally, the rising consumption of fish and its derivatives, due to its nutritional value and divergence of international cuisines, has led to an increase in reports of adverse reactions to fish. Reactions to fish are not only mediated by the immune system causing allergies, but are often caused by various toxins and parasites including ciguatera and Anisakis. Allergic reactions to fish can be serious and life threatening and children usually do not outgrow this type of food allergy. The route of exposure is not only restricted to ingestion but include manual handling and inhalation of cooking vapors in the domestic and occupational environment. Prevalence rates of self-reported fish allergy range from 0.2 to 2.29 % in the general population, but can reach up to 8 % among fish processing workers. Fish allergy seems to vary with geographical eating habits, type of fish processing, and fish species exposure. The major fish allergen characterized is parvalbumin in addition to several less well-known allergens. This contemporary review discusses interesting and new findings in the area of fish allergy including demographics, novel allergens identified, immunological mechanisms of sensitization, and innovative approaches in diagnosing and managing this life-long disease.

  8. Fish under exercise.

    Palstra, Arjan P; Planas, Josep V

    2011-06-01

    Improved knowledge on the swimming physiology of fish and its application to fisheries science and aquaculture (i.e., farming a fitter fish) is currently needed in the face of global environmental changes, high fishing pressures, increased aquaculture production as well as increased concern on fish well-being. Here, we review existing data on teleost fish that indicate that sustained exercise at optimal speeds enhances muscle growth and has consequences for flesh quality. Potential added benefits of sustained exercise may be delay of ovarian development and stimulation of immune status. Exercise could represent a natural, noninvasive, and economical approach to improve growth, flesh quality as well as welfare of aquacultured fish: a FitFish for a healthy consumer. All these issues are important for setting directions for policy decisions and future studies in this area. For this purpose, the FitFish workshop on the Swimming Physiology of Fish ( http://www.ub.edu/fitfish2010 ) was organized to bring together a multidisciplinary group of scientists using exercise models, industrial partners, and policy makers. Sixteen international experts from Europe, North America, and Japan were invited to present their work and view on migration of fishes in their natural environment, beneficial effects of exercise, and applications for sustainable aquaculture. Eighty-eight participants from 19 different countries contributed through a poster session and round table discussion. Eight papers from invited speakers at the workshop have been contributed to this special issue on The Swimming Physiology of Fish.

  9. Zoonoses associated with fish.

    Boylan, Shane

    2011-09-01

    The taxonomic group that composes the fishes is the most diverse group of vertebrates worldwide. The challenges of unique physiologies, a foreign environment, and many unknowns attract a passionate group of biologists and veterinarians. Economically, fishes have become vital as food, bait, and companion animals. Fishermen and fish handlers (processing plants) represent the historical human population exposed to fish zoonoses, but growth in aquaculture and aquarium hobbyists have led to an increase in published fish-borne zoonotic cases starting in the late 1950s that bloomed in the 1980s. Human physicians, particularly dermatologists and infectious disease specialists, are now more aware of fish-borne zoonoses, but they can be assisted with diagnosis when informed patients give more detailed histories with fish/water exposure.

  10. Investigation of Collective Behaviour and Electrocommunication in the Weakly Electric Fish, Mormyrus rume, through a biomimetic Robotic Dummy Fish.

    Donati, Elisa; Worm, Martin; Mintchev, Stefano; van der Wiel, Marleen; Benelli, Giovanni; von der Emde, Gerhard; Stefanini, Cesare

    2016-12-01

    A robotic fish has been developed to create a mixed bio-hybrid system made up of weakly electric fish and a mobile dummy fish. Weakly electric fish are capable of interacting with each other via sequences of self-generated electric signals during electrocommunication. Here we present the design of an artificial dummy fish, which is subsequently tested in behavioural experiments. The robot consists of two parts: a flexible tail that can move at different frequencies and amplitudes, performing a carangiform oscillation, and a rigid head containing the motor for the tail oscillation. The dummy fish mimics the weakly electric fish Mormyrus rume in morphology, size and electric signal generation. In order to study electrical interactions, the dummy fish is equipped with ten electrodes that record electric signals of nearby real fish and generate electric dipole fields around itself that are similar to those produced by real fish in both waveform and sequence. Behavioural experiments demonstrate that the dummy fish is able to recruit both single individuals and groups of M. rume from a shelter into an exposed area. The development of an artificial dummy fish may help to understand fundamental aspects of collective behaviour in weakly electric fish and the properties necessary to initiate and sustain it in closed-loop feedback experiments based on electrocommunication.

  11. Southeast Alaska ESI: FISH (Fish Polygons)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains biological resource data for estuarine, benthic, and pelagic fish in Southeast Alaska. Vector polygons in this data set represent locations of...

  12. Columbia River ESI: FISH (Fish Polygons)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for marine, estuarine, anadromous, and freshwater fish species in Columbia River. Vector polygons in this...

  13. North Slope, Alaska ESI: FISH (Fish Polygons)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for marine, estuarine, anadromous, and freshwater fish species for the North Slope of Alaska. Vector...

  14. American Samoa ESI: FISH (Fish Polygons)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for reef, pelagic, benthic, and estuarine fish species in American Samoa. Vector polygons in this data set...

  15. Plant Landscape Design of Fish-like Mouth Wetland Park in Nanjing%南京河西鱼嘴湿地公园植物景观规划

    曹航南; 周忠胜; 张文豹; 吴俊宏; 金雅琴

    2015-01-01

    以南京河西鱼嘴湿地公园为例,介绍公园景观规划的原则和功能定位,阐明植物景观构成要素的营建方法。分别从公园的重点区域植物景观营造、植物物种配置等方面分析该公园湿地植被恢复的设计思想,并对公园景观改造中地形地貌的设计、水系设计进行了探讨。%Taken Fish-like Mouth Wetland Park in Nanjing river-west for example,this paper introduced the function position of landscape planning on the park,and illustrated the construction method of plant landscape ele-ments.Besides,plants landscape planning,species disposition in two aspects proposed new design strategy of ur-ban wetland park.Meanwhile,topography design and water system design in the process of landscape renovation were discussed.The article provided the theory and technique reference for wetland restoration and ecological re-building along the Yangtze River.

  16. Fish elevator and method of elevating fish

    Truebe, Jonathan; Drooker, Michael S.

    1984-01-01

    A means and method for transporting fish from a lower body of water to a higher body of water. The means comprises a tubular lock with a gated entrance below the level of the lower body of water through which fish may enter the lock and a discharge passage above the level of the upper body of water. The fish raising means in the lock is a crowder pulled upward by a surface float as water from the upper body of water gravitationally flows into the closed lock filling it to the level of the upper body. Water is then pumped into the lock to raise the level to the discharge passage. The crowder is then caused to float upward the remaining distance through the water to the level of the discharge passage by the introduction of air into a pocket on the underside of the crowder. The fish are then automatically discharged from the lock into the discharge passage by the out of water position of the crowder. The movement of the fish into the discharge passage is aided by the continuous overflow of water still being pumped into the lock. A pipe may be connected to the discharge passage to deliver the fish to a selected location in the upper body of water.

  17. The utilization of crude fish oil (CFO) to increase mudcrab (Scylla serrata) feed quality

    Lamid, Mirni; Agustono

    2017-02-01

    Crude fish oil is one of essential fatty acid sources, which is found in Sardinella lemuru. This research aims to study the quality improvement of mudcrab(Scylla serrata) feed. Four feed formulations were designed by using completely randomized design, including P0 = trash fish + 1% tapioca starch; P1=trash fish + 2.0% crude fish oil + 1% tapioca starch;, P2= trash fish +4.0% crude fish oil + 1% tapioca starch; P3=trash fish + 6.0% crude fish oil + 1% tapioca starch; P4=trash fish +8.0% crude fish oil + 1% tapioca starch, respectively, which were carried out in quadruplicate. This study showed that feed formulation significantly affected crude protein, crude fiber, crude lipid, ash, organic matter and nitrogen free extract and energy of mudcrab. The P2 feed was the best formulation but had a slight different from P3 formulation.

  18. Improving disease prevention and treatment in controlled fish culture

    Terech-Majewska Elżbieta

    2016-09-01

    Full Text Available The aim of the work was to evaluate long-term results of studies focusing on improving methods for preventing and treating fish diseases using selected natural and syntetic immunomodulators and vaccines in fish culture. Simultaneously, attention is drawn to infectious or environmental threats against which appropriately composed immunoprophylaxis can be used in production cycles. Fish culture is intensifying in Poland and globally, which means that the role of prevention and well-designed prophylaxis is of increasing significance to the prevention and treatment of fish diseases. Currently, 33 fish species are cultured in Poland as stocking material or for production. The primary methods for preventing diseases in controlled fish culture are ensuring the welfare of fish and other prophylactic methods, including immunoprophylaxis. Many infectious and non-infectious threats that can cause direct losses and limit fish culture are present in the aquatic environment. Fish diseases generally stem from the simultaneous action of many factors that coincide and are difficult to distinguish. Pesticides (organochlorine insecticides, organophosphorus herbicides, aromatic hydrocarbons, pentachlorophenol, heavy metals, and chemotherapeutics are particularly toxic to fish. Biodegradation, which is continual in aquatic environments, is a process by which toxic and other substances that negatively affect fish become bioavailable and impact the immune system, the functioning of which is a specific bioindicator of environmental quality. Innate immunity plays a key role in the defense against disadvantageous factors, which also include pathogens. Immunomodulation methods can protect resistance mechanisms, thereby increasing disease prevention and treatment in controlled fish culture.

  19. Using the decision ladder to understand road user decision making at actively controlled rail level crossings.

    Mulvihill, Christine M; Salmon, Paul M; Beanland, Vanessa; Lenné, Michael G; Read, Gemma J M; Walker, Guy H; Stanton, Neville A

    2016-09-01

    Rail level crossings (RLXs) represent a key strategic risk for railways worldwide. Despite enforcement and engineering countermeasures, user behaviour at RLXs can often confound expectations and erode safety. Research in this area is limited by a relative absence of insights into actual decision making processes and a focus on only a subset of road user types. One-hundred and sixty-six road users (drivers, motorcyclists, cyclists and pedestrians) completed a diary entry for each of 457 naturalistic encounters with RLXs when a train was approaching. The final eligible sample comprised 94 participants and 248 encounters at actively controlled crossings where a violation of the active warnings was possible. The diary incorporated Critical Decision Method probe questions, which enabled user responses to be mapped onto Rasmussen's decision ladder. Twelve percent of crossing events were non-compliant. The underlying decision making was compared to compliant events and a reference decision model to reveal important differences in the structure and type of decision making within and between road user groups. The findings show that engineering countermeasures intended to improve decision making (e.g. flashing lights), may have the opposite effect for some users because the system permits a high level of flexibility for circumvention. Non-motorised users were more likely to access information outside of the warning signals because of their ability to achieve greater proximity to the train tracks and the train itself. The major conundrum in resolving these issues is whether to restrict the amount of time and information available to users so that it cannot be used for circumventing the system or provide more information to help users make safe decisions.

  20. Framing Prospective Elementary Teachers' Conceptions of Dissolving as a Ladder of Explanations

    Subramaniam, Karthigeyan; Esprivalo Harrell, Pamela

    2013-11-01

    The paper details an exploratory qualitative study that investigated 61 prospective teachers' conceptual understanding of dissolving salt and sugar in water respectively. The study was set within a 15-week elementary science methods course that included a 5E learning cycle lesson on dissolving, the instructional context. Oversby's (Prim Sci Rev 63:6-19, 2002, Aspects of teaching secondary science, Routledge Falmer, London, 2002) ladder of explanations for the context of dissolving, current scientific explanations for dissolving and perspectives on conceptions and misconceptions provided the unified framework for the study. Concept maps, interview transcripts, written artifacts, and drawings and narratives were used as data to investigate these prospective teachers' conceptual understanding of dissolving throughout the 15-weeks of the methods course. Analysis revealed that participants' explanations of dissolving were predominantly descriptive explanations (39 %) and interpretative explanations (38 %), with lower percentage occurrences of intentional (14 %) and cause and effect (9 %) level explanations. Most of these explanations were also constructed by a set of loosely connected and reinforcing everyday concepts abstracted from common everyday experiences making them misconceptions. Implications include: (1) the need for science teacher educators to use multiple platforms to derive their prospective elementary teachers' conceptual understandings of science content; and (2) to identify and help them identify their own scientific conceptions and misconceptions and how they influence the construction of scientific/nonscientific explanations. Science teacher educators also need to emphasize the role of meaningful frameworks associated with the concept that is being introduced during the Engage phase of the 5E learning cycle. This is important because, relevant prior knowledge is associated with the knowledge of the particle theory of matter and both are part of larger

  1. Calculating three loop ladder and V-topologies for massive operator matrix elements by computer algebra

    Ablinger, J.; Schneider, C. [Johannes Kepler Univ., Linz (Austria). Research Inst. for Symbolic Computation; Behring, A.; Bluemlein, J.; Freitas, A. de [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Manteuffel, A. von [Mainz Univ. (Germany). Inst. fuer Physik

    2015-09-15

    Three loop ladder and V-topology diagrams contributing to the massive operator matrix element A{sub Qg} are calculated. The corresponding objects can all be expressed in terms of nested sums and recurrences depending on the Mellin variable N and the dimensional parameter ε. Given these representations, the desired Laurent series expansions in ε can be obtained with the help of our computer algebra toolbox. Here we rely on generalized hypergeometric functions and Mellin-Barnes representations, on difference ring algorithms for symbolic summation, on an optimized version of the multivariate Almkvist-Zeilberger algorithm for symbolic integration, and on new methods to calculate Laurent series solutions of coupled systems of differential equations. The solutions can be computed for general coefficient matrices directly for any basis also performing the expansion in the dimensional parameter in case it is expressible in terms of indefinite nested product-sum expressions. This structural result is based on new results of our difference ring theory. In the cases discussed we deal with iterative sum- and integral-solutions over general alphabets. The final results are expressed in terms of special sums, forming quasi-shuffle algebras, such as nested harmonic sums, generalized harmonic sums, and nested binomially weighted (cyclotomic) sums. Analytic continuations to complex values of N are possible through the recursion relations obeyed by these quantities and their analytic asymptotic expansions. The latter lead to a host of new constants beyond the multiple zeta values, the infinite generalized harmonic and cyclotomic sums in the case of V-topologies.

  2. Vaccination in Fish

    Chettri, Jiwan Kumar

    vaccines have reduced the need for usage of antibiotics with more than 99 % since the 1980s. Fish can be vaccinated by three different administration routes: injection, immersion and oral vaccination. Injection vaccination (intraperitoneal injection of vaccine) is the most time consuming and labor...... intensive method, which however, provides the best protection of the fish. Immersion vaccination is used for immunization of a high number of small fish is cost-efficient and fast (30 sec immersion into vaccine). Oral vaccination (vaccine in feed) is the least efficient. As in higher vertebrates fish...... respond to vaccination by increasing the specific antibody titer and by activating the cellular responses. My talk will cover vaccination methods in fish, immune responses and some adverse effect of oil-adjuvanted vaccines in fish with reference to our work in rainbow trout, Oncorhynchus mykiss....

  3. Do Fish Sleep?

    1995-01-01

    Most fish can’t shut their eyes, so it’s easy to think they don’t sleep. But that’s like assuming humans don’t sleep because we can’t shut our ears to drown out sound. In fact, many species of fish take time out during the day or (more often) at night to enter a sleeplike stage. Some of these fish float in place, others lie on the bottom。

  4. Fish and wildlife surveillance

    Poston, T.M.

    1995-06-01

    This section of the 1994 Hanford Site Environmental Report summarizes the monitoring of radioactive contaminants in fish and wildlife species that inhabit the Colombia River and Hanford Site. Wildlife have access to areas of the Site containing radioactive contamination, and fish can be exposed to contamination in spring water entering the river along the shoreline. Therefore, samples are collected at various locations annually, generally during the hunting or fishing season, for selected species.

  5. Intelligent Fish Freshness Assessment

    Hamid Gholam Hosseini

    2008-01-01

    Full Text Available Fish species identification and automated fish freshness assessment play important roles in fishery industry applications. This paper describes a method based on support vector machines (SVMs to improve the performance of fish identification systems. The result is used for the assessment of fish freshness using artificial neural network (ANN. Identification of the fish species involves processing of the images of fish. The most efficient features were extracted and combined with the down-sampled version of the images to create a 1D input vector. Max-Win algorithm applied to the SVM-based classifiers has enhanced the reliability of sorting to 96.46%. The realisation of Cyranose 320 Electronic nose (E-nose, in order to evaluate the fish freshness in real-time, is experimented. Intelligent processing of the sensor patterns involves the use of a dedicated ANN for each species under study. The best estimation of freshness was provided by the most sensitive sensors. Data was collected from four selected species of fishes over a period of ten days. It was concluded that the performance can be increased using individual trained ANN for each specie. The proposed system has been successful in identifying the number of days after catching the fish with an accuracy of up to 91%.

  6. Anglers' fishing problem

    Karpowicz, Anna

    2011-01-01

    The considered model will be formulated as related to "the fishing problem" even if the other applications of it are much more obvious. The angler goes fishing. He uses various techniques and he has at most two fishing rods. He buys a fishing ticket for a fixed time. The fishes are caught with the use of different methods according to the renewal processes. The fishes' value and the inter arrival times are given by the sequences of independent, identically distributed (i.i.d.) random variables with the known distribution functions. It forms the marked renewal--reward process. The angler's measure of satisfaction is given by the difference between the utility function, depending on the value of the fishes caught, and the cost function connected with the time of fishing. In this way, the angler's relative opinion about the methods of fishing is modelled. The angler's aim is to have as much satisfaction as possible and additionally he has to leave the lake before a fixed moment. Therefore his goal is to find two...

  7. Combating Illegal Fishing

    Sorin Stanciu

    2010-10-01

    Full Text Available Illegal, unreported and unregulated (IUU fishing is a worldwide phenomenon. Its extent and its environmental,economic and social consequences are such that it has become a priority issue at international level. IUU fishingcontributes to the depletion of fish stocks and jeopardises protection and recovery measures put in place to ensure theviability of resources. It represents unfair competition for those who exploit fish resources legally. The Commissionhave been involved in the fight against IUU fishing for over a decade and in 2002 the Commission adopted an ActionPlan against IUU fishing inspired by the FAOs International Plan of Action to prevent, deter and eliminate IUUfishing of 2001. However, despite regional and international efforts to stop IUU fishing the phenomenon is still agrowing problem and as a result, the European Community intensified its action towards IUU fishing by launching aconsultation process in 2007. A Proposal to prevent, deter and eliminate IUU fishing was adopted in October 2007and a Regulation to prevent, deter and eliminate illegal, unreported and unregulated (IUU fishing was adopted on 29September 2008, after a unanimous political agreement.

  8. Meat, Poultry and Fish

    ... types of fish may contain high levels of mercury, PCBs (polychlorinated biphenyls), dioxins and other environmental contaminants. Shark, swordfish, tilefish (golden bass or golden snapper) and ...

  9. Yakima Basin Fish Passage Project, Phase 2

    1991-08-01

    Implementation of the Yakima Basin Fish Passage Project -- Phase 2 would significantly improve the production of anadromous fish in the Yakima River system. The project would provide offsite mitigation and help to compensate for lower Columbia River hydroelectric fishery losses. The Phase 2 screens would allow greater numbers of juvenile anadromous fish to survive. As a consequence, there would be higher returns of adult salmon and steelhead to the Yakima River. The proposed action would play an integral part in the overall Yakima River anadromous fish enhancement program (fish passage improvement, habitat enhancement, hatchery production increases, and harvest management). These would be environmental benefits associated with implementation of the Fish Passage and Protective Facilities Phase 2 Project. Based on the evaluation presented in this assessment, there would be no significant adverse environmental impacts if the proposed action was carried forward. No significant adverse environmental effects have been identified from construction and operation of the Yakima Phase 2 fish passage project. Proper design and implementation of the project will ensure no adverse effects will occur. Based on the information in this environmental analysis, BPA's and Reclamation's proposal to construct these facilities does not constitute a major Federal action that could significantly affect the quality of the human environment. 8 refs., 4 figs., 6 tabs.

  10. Generation of non-classical correlated photon pairs via a ladder-type atomic configuration: theory and experiment.

    Ding, Dong-Sheng; Zhou, Zhi-Yuan; Shi, Bao-Sen; Zou, Xu-Bo; Guo, Guang-Can

    2012-05-07

    We experimentally generate a non-classical correlated two-color photon pair at 780 and 1529.4 nm in a ladder-type configuration using a hot 85Rb atomic vapor with the production rate of ~10(7)/s. The non-classical correlation between these two photons is demonstrated by strong violation of Cauchy-Schwarz inequality by the factor R = 48 ± 12. Besides, we experimentally investigate the relations between the correlation and some important experimental parameters such as the single-photon detuning, the powers of pumps. We also make a theoretical analysis in detail and the theoretical predictions are in reasonable agreement with our experimental results.

  11. Four-Wave Mixing Scheme in a Four-Level Ladder-Type Atomic System Based on Electromagnetically Induced Transparency

    LI Jia-Hua; CHEN Ai-Xi; PENG Ju-Cun

    2004-01-01

    @@ A nonlinear optical four-wave mixing scheme is presented and analysed for the generation of coherent light in a nearly four-level ladder-type atomic system in the context of electromagnetically induced transparency (EIT).We find that EIT can suppress nonlinear photon absorption and the peak of the generated mixing field is located at the centre of the transparency window where the loss is minimal, though there is a dip in the centre. Such a nonlinear optical process can also be used for generating coherent short-wavelength radiation.

  12. Direct Observation of Ultrafast Field-Induced Charge Generation in Ladder-Type Poly(Para-Phenylene)

    Graupner, W.; Cerullo, G.; Lanzani, G.; Nisoli, M.; List, E. J. W.; Leising, G.; de Silvestri, S.

    1998-10-01

    Electric field-induced charge photogeneration in ladder-type poly(para-phenylene) is investigated by field-assisted femtosecond pump-probe experiments carried out on light emitting diodes. The characteristic photoinduced absorption band at 1.9 eV allows one to directly monitor the polaron population. We find that polarons are formed by exciton fission without intermediate states on a time scale of 10 ps. The buildup kinetics of the polaron population suggests a dissociation driven by exciton diffusion during interchain thermalization.

  13. Photogeneration Action Spectroscopy of Neutral and Charged Excitations in Films of a Ladder-Type Poly(Para-Phenylene)

    Wohlgenannt, M.; Graupner, W.; Leising, G.; Vardeny, Z. V.

    1999-04-01

    The photogeneration quantum efficiency action spectra of long-lived neutral and charged excitations in films of a ladder-type poly(para-phenylene) were measured. We found that both triplet and polaron action spectra show, in addition to a step function increase at the optical gap, a monotonic rise at higher energies. For triplets this rise is explained by singlet exciton fission into triplet pairs from which the triplet exciton energy in the gap was obtained; this energy was also confirmed by measuring the weak phosphorescence band. For polarons the photogeneration increase at high energies is modeled by a novel hot electron interchain tunneling process.

  14. Surface acoustic BLOCH oscillations, the Wannier-Stark ladder, and Landau-Zener tunneling in a solid.

    de Lima, M M; Kosevich, Yu A; Santos, P V; Cantarero, A

    2010-04-23

    We present the experimental observation of Bloch oscillations, the Wannier-Stark ladder, and Landau-Zener tunneling of surface acoustic waves in perturbed grating structures on a solid substrate. A model providing a quantitative description of our experimental observations, including multiple Landau-Zener transitions of the anticrossed surface acoustic Wannier-Stark states, is developed. The use of a planar geometry for the realization of the Bloch oscillations and Landau-Zener tunneling allows a direct access to the elastic field distribution. The vertical surface displacement has been measured by interferometry.

  15. Demonstration of photon Bloch oscillations and Wannier-Stark ladders in dual-periodical multilayer structures based on porous silicon.

    Estevez, J Octavio; Arriaga, Jesús; Mendez-Blas, Antonio; Reyes-Ayona, Edgar; Escorcia, José; Agarwal, Vivechana

    2012-07-23

    : Theoretical demonstration and experimental evidence of photon Bloch oscillations and Wannier-Stark ladders (WSLs) in dual-periodical (DP) multilayers, based on porous silicon, are presented. An introduction of the linear gradient in refractive indices in DP structure, which is composed by stacking two different periodic substructures N times, resulted in the appearance of WSLs. Theoretical time-resolved reflection spectrum shows the photon Bloch oscillations with a period of 130 fs. Depending on the values of the structural parameters, one can observe the WSLs in the near infrared or visible region which may allow the generation of terahertz radiation with a potential applications in several fields like imaging.

  16. Modified Spin Wave Analysis of Low Temperature Properties of the Spin-1/2 Frustrated Ferromagnetic Ladder

    Hida, Kazuo; Iino, Takashi

    2012-03-01

    Low temperature properties of the spin-1/2 frustrated ladder with ferromagnetic rungs and legs, and two different antiferromagnetic next nearest neighbor interactions are investigated using the modified spin wave approximation in the region with ferromagnetic ground states. The temperature dependence of the magnetic susceptibility and magnetic structure factors is calculated. The results are consistent with the numerical exact diagonalization results in the intermediate temperature range. Below this temperature range, the finite size effect is significant in the numerical diagonalization results, while the modified spin wave approximation gives more reliable results. The low temperature properties near the limit of the stability of the ferromagnetic ground state are also discussed.

  17. Shifted Landau ladders and low field magneto-oscillations in high-mobility GaAs 2D hole systems

    Zhang, Po; Wang, Jianli; Zhang, Chi; Du, Rui-Rui; Pfeiffer, L. N.; West, K. W.

    2017-03-01

    We present well-developed low-field magneto-resistance oscillations originating from zero-field spin splitting (ZFSS) of heavy holes in high mobility GaAs/AlGaAs quantum wells. This low field oscillation is 1/B-periodic and emerges before the onset of Shubnikov-de Haas oscillations. The effect can be explained by resonant scattering between two Landau ladders shifted by the ZFSS gap, which in turn can be measured by comparing with the hole cyclotron energy. A front gate is fabricated to tune the ZFSS and hence the oscillation period.

  18. Parton Ladder Splitting and the Rapidity Dependence of Transverse Momentum Spectra in Deuteron-Gold Collisions at RHIC

    Werner, K; Pierog, T; Werner, Klaus; Liu, Fu-Ming; Pierog, Tanguy

    2006-01-01

    We present a phenomenological approach (EPOS), based on the parton model, but going much beyond, and try to understand proton-proton and deuteron-gold collisions, in particular the transverse momentum results from all the four RHIC experiments. It turns out that elastic and inelastic parton ladder splitting is the key issue. Elastic splitting is in fact related to screening and saturation, but much more important is the inelastic contribution, being crucial to understand the data. We investigate in detail the rapidity dependence of nuclear effects, which is actually relatively weak in the model, in perfect agreement with the data, if the latter ones are interpreted correctly.

  19. Fish Springs NWR mammal, fish, amphibian, and reptile list

    US Fish and Wildlife Service, Department of the Interior — The following is a species list for mammals, fishes, amphibians, and reptiles found on or adjacent to Fish Springs National Wildlife Refuge, as of October, 1996.

  20. CO-Selenium in fish tissue: Prediction equations for conversion between whole body, muscle, and eggs

    US Fish and Wildlife Service, Department of the Interior — The lower Gunnison River and the Colorado River are designated critical habitat for two endangered fish species: the Colorado pikeminnow (Ptychocheilus lucius) and...

  1. Alaskan sport fishing waters

    US Fish and Wildlife Service, Department of the Interior — As a guide to newcomers and visitors, fishery biologists have compiled a list of some of the well-known fishing waters in Alaska. The list is merely a starting point...

  2. Virus diseases of fish

    Watson, Stanley W.

    1954-01-01

    Viruses are probably the cause of a wide spectrum of fish diseases. Although relatively few virus diseases of fish are known today, some of the diseases of unknown etiology, as well as some diseases presently accepted as due to bacteria, protozoa, fungi or nutritional deficiencies, possibly will be recognized eventually as virus diseases.

  3. PARASITES OF FISH

    The intent of this chapter is to describe the parasites of importance to fishes maintained and used in laboratory settings. In contrast to the frist edition, the focus will be only on those parasites that pose a serious threat to or are common in fishes held in these confined en...

  4. Folkbiology of Freshwater Fish

    Medin, Douglas L.; Ross, Norbert O.; Atran, Scott; Cox, Douglas; Coley, John; Proffitt, Julia B.; Blok, Sergey

    2006-01-01

    Cross-cultural comparisons of categorization often confound cultural factors with expertise. This paper reports four experiments on the conceptual behavior of Native American and majority-culture fish experts. The two groups live in the same general area and engage in essentially the same set of fishing-related behaviors. Nonetheless, cultural…

  5. Design

    Jensen, Ole B.; Pettiway, Keon

    2017-01-01

    by designers, planners, etc. (staging from above) and mobile subjects (staging from below). A research agenda for studying situated practices of mobility and mobilities design is outlined in three directions: foci of studies, methods and approaches, and epistemologies and frames of thinking. Jensen begins......In this chapter, Ole B. Jensen takes a situational approach to mobilities to examine how ordinary life activities are structured by technology and design. Using “staging mobilities” as a theoretical approach, Jensen considers mobilities as overlapping, actions, interactions and decisions...... with a brief description of how movement is studied within social sciences after the “mobilities turn” versus the idea of physical movement in transport geography and engineering. He then explains how “mobilities design” was derived from connections between traffic and architecture. Jensen concludes...

  6. Design

    Volf, Mette

    Design - proces & metode iBog®  er enestående i sit fokus på afmystificering og operationalisering af designprocessens flygtige og komplekse karakter. Udgivelsen går bag om designerens daglige arbejde og giver et indblik i den kreative skabelsesproces, som designeren er en del af. Udover et bredt...... indblik i designerens arbejdsmetoder og designparametre giver Design - proces & metode en række eksempler fra anerkendte designvirksomheder, der gør det muligt at komme helt tæt på designerens virkelighed....

  7. From Fishing to Fish Processing: Separation of Fish from Crustaceans in the Norway Lobster-Directed Multispecies Trawl Fishery Improves Seafood Quality.

    Junita D Karlsen

    Full Text Available Fishing gears have negative impacts on seafood quality, especially on fish in the mixed trawl fishery targeting Norway lobster (Nephrops norvegicus. In this fishery, which is worth about €80 millions in Denmark alone, the quality of fish can be significantly improved by simple gear changes. A trawl codend divided into an upper and lower codend was designed to separate fish from Norway lobster during the fishing process by encourage fish to swim into the upper codend by using a frame at the entrance of the lower codend. Separate codends for fish and Norway lobster in the same gear provide the opportunity to selectively reduce small low-value fish, which will reduce catch weight and sorting time onboard the vessel. For this horizontally divided test codend and a standard codend, in which the catch was mixed, quality assessments were performed on the same batches of fish during three steps of the value chain: i aboard the fishing vessel; ii at the Fishermen's Collection Central, and iii in the production plant. Four species of fish and fillets from fish caught in the upper codend of the test codend were of significantly better quality for several of the assessed parameters compared with those caught in the standard codend: i newly caught fish showed significantly less scale loss and discolourations and had significantly better texture; ii landed fish had significantly better skin appearance and texture and significantly fewer discolourations; and iii fillets showed significantly fewer blood spots and had significantly better texture. There were no differences in injuries for newly caught fish or gaping and bruises for fillets between the test and standard codends. The decrease in catch-related damages in the test codend is explained by little contact between fish and animals with hard or spiny surfaces due to successful separation of fish and Norway lobster into the upper and lower codends, respectively, and by lower catch weight in the upper

  8. From Fishing to Fish Processing: Separation of Fish from Crustaceans in the Norway Lobster-Directed Multispecies Trawl Fishery Improves Seafood Quality.

    Karlsen, Junita D; Krag, Ludvig Ahm; Albertsen, Christoffer Moesgaard; Frandsen, Rikke Petri

    2015-01-01

    Fishing gears have negative impacts on seafood quality, especially on fish in the mixed trawl fishery targeting Norway lobster (Nephrops norvegicus). In this fishery, which is worth about €80 millions in Denmark alone, the quality of fish can be significantly improved by simple gear changes. A trawl codend divided into an upper and lower codend was designed to separate fish from Norway lobster during the fishing process by encourage fish to swim into the upper codend by using a frame at the entrance of the lower codend. Separate codends for fish and Norway lobster in the same gear provide the opportunity to selectively reduce small low-value fish, which will reduce catch weight and sorting time onboard the vessel. For this horizontally divided test codend and a standard codend, in which the catch was mixed, quality assessments were performed on the same batches of fish during three steps of the value chain: i) aboard the fishing vessel; ii) at the Fishermen's Collection Central, and iii) in the production plant. Four species of fish and fillets from fish caught in the upper codend of the test codend were of significantly better quality for several of the assessed parameters compared with those caught in the standard codend: i) newly caught fish showed significantly less scale loss and discolourations and had significantly better texture; ii) landed fish had significantly better skin appearance and texture and significantly fewer discolourations; and iii) fillets showed significantly fewer blood spots and had significantly better texture. There were no differences in injuries for newly caught fish or gaping and bruises for fillets between the test and standard codends. The decrease in catch-related damages in the test codend is explained by little contact between fish and animals with hard or spiny surfaces due to successful separation of fish and Norway lobster into the upper and lower codends, respectively, and by lower catch weight in the upper codend of the

  9. From Fishing to Fish Processing: Separation of Fish from Crustaceans in the Norway Lobster-Directed Multispecies Trawl Fishery Improves Seafood Quality

    Karlsen, Junita D.; Krag, Ludvig Ahm; Albertsen, Christoffer Moesgaard; Frandsen, Rikke Petri

    2015-01-01

    Fishing gears have negative impacts on seafood quality, especially on fish in the mixed trawl fishery targeting Norway lobster (Nephrops norvegicus). In this fishery, which is worth about €80 millions in Denmark alone, the quality of fish can be significantly improved by simple gear changes. A trawl codend divided into an upper and lower codend was designed to separate fish from Norway lobster during the fishing process by encourage fish to swim into the upper codend by using a frame at the entrance of the lower codend. Separate codends for fish and Norway lobster in the same gear provide the opportunity to selectively reduce small low-value fish, which will reduce catch weight and sorting time onboard the vessel. For this horizontally divided test codend and a standard codend, in which the catch was mixed, quality assessments were performed on the same batches of fish during three steps of the value chain: i) aboard the fishing vessel; ii) at the Fishermen’s Collection Central, and iii) in the production plant. Four species of fish and fillets from fish caught in the upper codend of the test codend were of significantly better quality for several of the assessed parameters compared with those caught in the standard codend: i) newly caught fish showed significantly less scale loss and discolourations and had significantly better texture; ii) landed fish had significantly better skin appearance and texture and significantly fewer discolourations; and iii) fillets showed significantly fewer blood spots and had significantly better texture. There were no differences in injuries for newly caught fish or gaping and bruises for fillets between the test and standard codends. The decrease in catch-related damages in the test codend is explained by little contact between fish and animals with hard or spiny surfaces due to successful separation of fish and Norway lobster into the upper and lower codends, respectively, and by lower catch weight in the upper codend of the

  10. Biannual Fish Survey, Spring 1993

    US Fish and Wildlife Service, Department of the Interior — The biannual fish survey was initiated in 1989 to monitor population trends of federally endangered fish species at Ash Meadows National Wildlife Refuge. Item 421 of...

  11. Simulation of TunneLadder traveling-wave tube cold-test characteristics: Implementation of the three-dimensional, electromagnetic circuit analysis code micro-SOS

    Kory, Carol L.; Wilson, Jeffrey D.

    1993-01-01

    The three-dimensional, electromagnetic circuit analysis code, Micro-SOS, can be used to reduce expensive time-consuming experimental 'cold-testing' of traveling-wave tube (TWT) circuits. The frequency-phase dispersion characteristics and beam interaction impedance of a TunneLadder traveling-wave tube slow-wave structure were simulated using the code. When reasonable dimensional adjustments are made, computer results agree closely with experimental data. Modifications to the circuit geometry that would make the TunneLadder TWT easier to fabricate for higher frequency operation are explored.

  12. Design

    Buchanan, Richard; Cross, Nigel; Durling, David; Nelson, Harold; Owen, Charles; Valtonen, Anna; Boling, Elizabeth; Gibbons, Andrew; Visscher-Voerman, Irene

    2013-01-01

    Scholars representing the field of design were asked to identify what they considered to be the most exciting and imaginative work currently being done in their field, as well as how that work might change our understanding. The scholars included Richard Buchanan, Nigel Cross, David Durling, Harold Nelson, Charles Owen, and Anna Valtonen. Scholars…

  13. Design

    Volf, Mette

    2009-01-01

    Design - proces og metode går bag om designerens arbejde og giver et indblik i den skabelsesproces, som designeren er involveret i. Bogen er enestående, fordi den fokuserer på processens flygtige og komplekse karakter, afmystificerer den og gør den operationel - uden at fjerne dens magi. Ud over...

  14. Heat Conductivity of the Heisenberg Spin-1/2 Ladder: From Weak to Strong Breaking of Integrability.

    Steinigeweg, Robin; Herbrych, Jacek; Zotos, Xenophon; Brenig, Wolfram

    2016-01-08

    We investigate the heat conductivity κ of the Heisenberg spin-1/2 ladder at finite temperature covering the entire range of interchain coupling J(⊥), by using several numerical methods and perturbation theory within the framework of linear response. We unveil that a perturbative prediction κ∝J(⊥)(-2), based on simple golden-rule arguments and valid in the strict limit J(⊥)→0, applies to a remarkably wide range of J(⊥), qualitatively and quantitatively. In the large J(⊥) limit, we show power-law scaling of opposite nature, namely, κ∝J(⊥)(2). Moreover, we demonstrate the weak and strong coupling regimes to be connected by a broad minimum, slightly below the isotropic point at J(⊥)=J(∥). Reducing temperature T, starting from T=∞, this minimum scales as κ∝T(-2) down to T on the order of the exchange coupling constant. These results provide for a comprehensive picture of κ(J(⊥),T) of spin ladders.

  15. Finite element analysis and experiment research on aluminum alloy ladder bowl with viscous pressure forming(VPF)

    2002-01-01

    The process parameters of aluminum alloy ladder bowl with viscous pressure forming and solid metal punch forming were numerically simulated by commercial finite element software DEFORM.The influence of blank holder pressure(BHP)on the formability of sheet metal was investigated.It was found that lower BHP does benefit to the distribution of thickness both with VPF and with solid punch forming.The forming force needed in VPF is bigger than that of with solid punch forming at the same stroke.The distribution of thickness with VPF is more uniform than that of with solid punch forming.Compared with solid punch forming,the damage values of workpiece at the top convex comer are lower by VPF.It was also shown that fracture tendency could be reduced with VPF,so that means the formability is improved.At the same time,aluminum alloy ladder bowl was manufactured with VPF.The results show that the simulation results are in agreement with the experimental data very well.

  16. Constructing a ladder of transnational partnership working in support of marine spatial planning: thoughts from the Irish Sea.

    Kidd, Sue; McGowan, Lynne

    2013-09-15

    This paper adds to the growing body of literature on partnerships and Marine Spatial Planning (MSP) by constructing a ladder of transnational partnership working which can act as an aid to partnership development. The first part draws upon partnership working and co-management literature and identifies 5 levels of transnational partnership working: Information Sharing; Administration Sharing; Agreed Joint Rules; Combined Organisation; and Combined Constitution and illustrates what these might entail with reference to established maritime partnerships. The second part of the paper then explores how these generic levels may be used to structure transnational partnership development in a particular marine setting. This draws upon the outputs of two Irish Sea Transnational Partnership Working events which were funded by the UK's Economic and Social Research Council, and in particular on the exploration of motivations for collaboration which was a key point of discussion. In conclusion the paper considers the strengths and weaknesses of the ladder and how it may be enhanced and used more widely to better understand and analyse existing transnational partnership activity and guide the development of new transnational partnerships in support of MSP.

  17. Effects of a Novel Fish Transport System on the Health of Adult Fall Chinook Salmon

    Geist, David R.; Colotelo, Alison H.; Linley, Timothy J.; Wagner, Katie A.; Miracle, Ann L.

    2016-12-01

    Movement past hydroelectric dams and related in-river structures has important implications for habitat connectivity and population persistence in migratory fish. A major problem is that many of these structures lack effective fish passage facilities, which can fragment spawning and rearing areas and negatively impact recruitment. While traditional fish passage facilities (e.g., ladders, trap and haul) can effectively enable fish to pass over barriers, their capital or operational costs can be significant. We evaluated the utility of a novel transport device that utilizes a flexible tube with differential internal air pressure to pass fish around in-river barriers. Three treatments and a control group were tested. In two of the treatments, adult fall Chinook Salmon nearing maturation were transported through the device via two lengths of tube (12 or 77 m) and their injury, stress, and immune system responses and reproductive function were compared to a third treatment where fish were moved by a standard trap and haul method and also to a control group. We observed no significant differences among the treatment or control groups in post-treatment adult survival, injury or stress. Indicators of immune system response and reproductive readiness were also not significantly different among the four groups. Egg survival was significantly different among the groups, but the differences were highly variable within groups and not consistent with the duration of treatment or degree of handling. Taken together, the results suggest the device did not injure or alter normal physiological functioning of adult fall Chinook Salmon nearing maturation and may provide an effective method for transporting such fish around in-river barriers during their spawning migration. Keywords: Whooshh, transport, in-stream barriers, hydropower

  18. Design of Studies for Development of BPA Fish and Wildlife Mitigation Accounting Policy Phase II, Volume II, 1985-1988 Technical Report.

    Kneese, Allen V.

    1988-08-01

    The incremental costs of corrective measures to lessen the environmental impacts of the hydroelectric system are expected to increase and difficult questions to arise about the costs, effectiveness, and justification of alternative measures and their systemwide implications. The BPA anticipate this situation by launching a forward-looking research program aimed at providing methodological tools and data suitable for estimating the productivity and cost implications of mitigation alternatives in a timely manner with state-of-the-art accuracy. Resources for the Future (RFF) agreed at the request of the BPA to develop a research program which would provide an analytical system designed to assist the BPA Administrator and other interested and responsible parties in evaluating the ecological and economic aspects of alternative protection, enhancement, and mitigation measures. While this progression from an ecological understanding to cost-effectiveness analyses is straightforward in concept, the complexities of the Columbia River system make the development of analytical methods far from simple in practice. The Phase 2 final report outlines the technical issues involved in developing an analytical system and proposes a program of research to address these issues. The report is presented in the Summary Report (Volume 1), and the present volume which consists of three technical reports: Part I, Modeling the Salmon and Steelhead Fisheries of the Columbia River Basin; Part II, Models for Cost-Effectiveness Analysis; and Part III, Ocean Fisheries Harvest Management.

  19. 50 CFR 697.19 - Trap limits and trap tag requirements for vessels fishing with lobster traps.

    2010-10-01

    ... vessels fishing with lobster traps. 697.19 Section 697.19 Wildlife and Fisheries FISHERY CONSERVATION AND... requirements for vessels fishing with lobster traps. (a) Trap limits for vessels fishing or authorized to fish... management area designation certificate or valid limited access American lobster permit specifying one...

  20. Olfactory toxicity in fishes.

    Tierney, Keith B; Baldwin, David H; Hara, Toshiaki J; Ross, Peter S; Scholz, Nathaniel L; Kennedy, Christopher J

    2010-01-21

    Olfaction conveys critical environmental information to fishes, enabling activities such as mating, locating food, discriminating kin, avoiding predators and homing. All of these behaviors can be impaired or lost as a result of exposure to toxic contaminants in surface waters. Historically, teleost olfaction studies have focused on behavioral responses to anthropogenic contaminants (e.g., avoidance). More recently, there has been a shift towards understanding the underlying mechanisms and functional significance of contaminant-mediated changes in fish olfaction. This includes a consideration of how contaminants affect the olfactory nervous system and, by extension, the downstream physiological and behavioral processes that together comprise a normal response to naturally occurring stimuli (e.g., reproductive priming or releasing pheromones). Numerous studies spanning several species have shown that ecologically relevant exposures to common pollutants such as metals and pesticides can interfere with fish olfaction and disrupt life history processes that determine individual survival and reproductive success. This represents one of the pathways by which toxic chemicals in aquatic habitats may increasingly contribute to the decline and at-risk status of many commercially and ecologically important fish stocks. Despite our emerging understanding of the threats that pollution poses for chemical communication in aquatic communities, many research challenges remain. These include: (1) the determination of specific mechanisms of toxicity in the fish olfactory sensory epithelium; (2) an understanding of the impacts of complex chemical mixtures; (3) the capacity to assess olfactory toxicity in fish in situ; (4) the impacts of toxins on olfactory-mediated behaviors that are still poorly understood for many fish species; and (5) the connections between sublethal effects on individual fish and the long-term viability of wild populations. This review summarizes and integrates