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Sample records for critical gap distance

  1. Critical Gap distance in Laser Butt-welding

    DEFF Research Database (Denmark)

    Bagger, Claus; Olsen, Flemming Ove

    of "reference" welds are made and compared to sheets with the edges shear cut. The gap distance is precisely controlled by inserting spacers between the sheets. In the tests the gap is set at 0.00, 0.02, 0.05, 0.08 and 0.10 mm. Mild steel (St 1203) with thickness? of 0.75 and 1.25 mm with and without zinc......When butt-welding metal sheets with high power lasers the gap distance between the sheets determine the final quality of the seam. In a number of systematic laboratory experiments the critical gap distance that results in sound beads is identified. By grinding the edges of the sheets, a number...... coating were analysed. A total of 120 welds are made at different welding speeds.As quality norm DIN 8563 is used to divide the welds into quality classes. Since this norm only deals with surface defects a number of welds are also x-ray photographed.According to DIN 8563 the welds have classes of either B...

  2. Critical Gap distance in Laser Butt-welding

    DEFF Research Database (Denmark)

    Bagger, Claus; Olsen, Flemming Ove

    1999-01-01

    In a number of systematic laboratory experiments the critical gap distance that results in sound beads in laser butt welding is sought identified. By grinding the edges of the sheets, a number of "reference" welds are made and compared to the sheets with shear cut edges. In the tests the gap...... was set at 0.00, 0.02, 0.05, 0.08 and 0.10 mm. Mild steel (St 1203) with a thickness of 0.75 and 1.25 mm with and without zinc coating were analysed. A total of 120 welds were made at different welding speeds.As quality norm DIN 8563 was used to divide the welds into quality classes. A number of welds...... were also x-ray photographed.Of the weld combinations analysed 80 % were of high quality and 17 % of a non-acceptable quality. 90 % of the bad welds had a gap distance larger than 0.05 mm. The results showed that 85 % of the bad welds were shear cut and only 15 % grinded. Two third of the bad welds...

  3. Compressions of electrorheological fluids under different initial gap distances.

    Science.gov (United States)

    Tian, Yu; Wen, Shizhu; Meng, Yonggang

    2003-05-01

    Compressions of electrorheological (ER) fluids have been carried out under different initial gap distances and different applied voltages. The nominal yield stresses of the compressed ER fluid under different conditions, according to the mechanics of compressing continuous fluids considering the yield stress of the plastic fluid, have been calculated. Curves of nominal yield stress under different applied voltages at an initial gap distance of 4 mm overlapped well and were shown to be proportional to the square of the external electric field and agree well with the traditional description. With the decrease of the initial gap distance, the difference between the nominal yield stress curves increased. The gap distance effect on the compression of ER fluids could not be explained by the traditional description based on the Bingham model and the continuous media theory. An explanation based on the mechanics of particle chain is proposed to describe the gap distance effect on the compression of ER fluids.

  4. Critical Points in Distance Learning System

    Directory of Open Access Journals (Sweden)

    Airina Savickaitė

    2013-08-01

    Full Text Available Purpose – This article presents the results of distance learning system analysis, i.e. the critical elements of the distance learning system. The critical points of distance learning are a part of distance education online environment interactivity/community process model. The most important is the fact that the critical point is associated with distance learning participants. Design/methodology/approach – Comparative review of articles and analysis of distance learning module. Findings – A modern man is a lifelong learner and distance learning is a way to be a modern person. The focus on a learner and feedback is the most important thing of learning distance system. Also, attention should be paid to the lecture-appropriate knowledge and ability to convey information. Distance system adaptation is the way to improve the learner’s learning outcomes. Research limitations/implications – Different learning disciplines and learning methods may have different critical points. Practical implications – The information of analysis could be important for both lecturers and students, who studies distance education systems. There are familiar critical points which may deteriorate the quality of learning. Originality/value – The study sought to develop remote systems for applications in order to improve the quality of knowledge. Keywords: distance learning, process model, critical points. Research type: review of literature and general overview.

  5. The effect of critical distance in stability condition for the crack at the interface between two materials

    Czech Academy of Sciences Publication Activity Database

    Zouhar, Michal; Hutař, Pavel; Náhlík, Luboš; Ševčík, Martin; Knésl, Zdeněk

    2012-01-01

    Roč. 19, 2/3 (2012), s. 155-164 ISSN 1802-1484 R&D Projects: GA ČR(CZ) GAP107/10/0361; GA ČR(CZ) GAP108/12/1560 Institutional support: RVO:68081723 Keywords : stability criterion * critical distance * bi-material interface Subject RIV: JL - Materials Fatigue, Friction Mechanics

  6. A study on critical heat flux in gap

    Energy Technology Data Exchange (ETDEWEB)

    Park, Rae Joon; Jeong, Ji Whan; Cho, Young Ro; Chang, Young Cho; Kang, Kyung Ho; Kim, Jong Whan; Kim, Sang Baik; Kim, Hee Dong

    1999-04-01

    The scope and content of this study is to perform the test on critical heat flux in hemispherical narrow gaps using distilled water and Freon R-113 as experimental parameters, such as system pressure from 1 to 10 atm and gap thickness of 0.5, 1.0, 2.0, and 5.0 mm. The CHFG test results have shown that the measured values of critical power are much lower than the predictions made by empirical CHF correlations applicable to flat plate gaps and annuli. The pressure effect on the critical power was found to be much milder than predictions by those CHF correlations. The values and the pressure trend of the critical powers measured in the present experiments are close to the values converted from the CCFL data. This confirms the claim that a CCFL brings about local dryout and finally, global dryout in hemispherical narrow gaps. Increases in the gap thickness lead to increase in critical power. The measured critical power using R-113 in hemispherical narrow gaps are 60 % lower than that using water due to the lower boiling point, which is different from the pool boiling condition. The CCFL (counter counter flow limit) test facility was constructed and the test is being performed to estimate the CCFL phenomena and to evaluate the CHFG test results on critical power in hemispherical narrow gaps. (Author). 35 refs., 2 tabs., 19 figs.

  7. A study on critical heat flux in gap

    International Nuclear Information System (INIS)

    Park, Rae Joon; Jeong, Ji Whan; Cho, Young Ro; Chang, Young Cho; Kang, Kyung Ho; Kim, Jong Whan; Kim, Sang Baik; Kim, Hee Dong

    1999-04-01

    The scope and content of this study is to perform the test on critical heat flux in hemispherical narrow gaps using distilled water and Freon R-113 as experimental parameters, such as system pressure from 1 to 10 atm and gap thickness of 0.5, 1.0, 2.0, and 5.0 mm. The CHFG test results have shown that the measured values of critical power are much lower than the predictions made by empirical CHF correlations applicable to flat plate gaps and annuli. The pressure effect on the critical power was found to be much milder than predictions by those CHF correlations. The values and the pressure trend of the critical powers measured in the present experiments are close to the values converted from the CCFL data. This confirms the claim that a CCFL brings about local dryout and finally, global dryout in hemispherical narrow gaps. Increases in the gap thickness lead to increase in critical power. The measured critical power using R-113 in hemispherical narrow gaps are 60 % lower than that using water due to the lower boiling point, which is different from the pool boiling condition. The CCFL (counter counter flow limit) test facility was constructed and the test is being performed to estimate the CCFL phenomena and to evaluate the CHFG test results on critical power in hemispherical narrow gaps. (Author). 35 refs., 2 tabs., 19 figs

  8. Experimental Study on Critical Power in a Hemispherical Narrow Gap

    International Nuclear Information System (INIS)

    Park, Rae-Joon; Ha, Kwang-Soon; Kim, Sang-Baik; Kim, Hee-Dong; Jeong, Ji-Hwan

    2002-01-01

    An experimental study of critical heat flux in gap (CHFG) has been performed to investigate the inherent cooling mechanism in a hemispherical narrow gap. The objectives of the CHFG test are to measure critical power from a critical heat removal rate through the hemispherical narrow gap using distilled water with experimental parameters of system pressure and gap width. The CHFG test results have shown that a countercurrent flow limitation (CCFL) brings about local dryout at the small edge region of the upper part and finally global dryout in a hemispherical narrow gap. Increases in the gap width and pressure lead to an increase in critical power. The measured values of critical power are lower than the predictions made by other empirical CHF correlations applicable to flat plate, annuli, and small spherical gaps. The measured data on critical power in the hemispherical narrow gaps have been correlated using nondimensional parameters with a range of approximately ±20%. The developed correlation has been expanded to apply the spherical geometry using the Siemens/KWU correlation

  9. The influence of gap distance on the random walk of cathode spot in vacuum arc

    International Nuclear Information System (INIS)

    Shi Zongqian; Xiao Jia; Jia Shenli; Liu Zhigang; Wang Lijun

    2007-01-01

    Experiments were conducted in a detachable vacuum chamber for Cu vacuum arc with arc current in the range 19-24 A. Experimental results indicated that the gap distance had a distinct influence on the characteristics of the random walk of the cathode spot (CS) for the gap distance adopted, i.e. d = 4.8 mm and d = 6.8 mm. It was found that the increase in the gap distance could lead to a larger diffusion parameter. Based on the dynamics of fragments constituting the CS, it was proposed that with a longer gap distance, the magnetic interaction between fragments would be strengthened. It would result in the increase of the mean step length of the CS and the decrease of the mean step time, which would lead to a larger diffusion parameter as observed. The plasma density in the region of the CS was also found to decrease with the increase in the gap distance. It would result in the CS having a higher probability of jumping to the contaminated region but not to the vicinity of the existing crater

  10. practice gap in critical care nursing students

    African Journals Online (AJOL)

    Guided reflection as a tool to deal with the theory– practice gap in critical care ... was used during semi-structured interviews during the data collection process. ... a description of incidents experienced, critical analysis of knowledge, critical ...

  11. Influence of Gap Distance on Vacuum Arc Characteristics of Cup Type AMF Electrode in Vacuum Interrupters

    International Nuclear Information System (INIS)

    Cheng Shaoyong; Xiu Shixin; Wang Jimei; Shen Zhengchao

    2006-01-01

    The greenhouse effect of SF 6 is a great concern today. The development of high voltage vacuum circuit breakers becomes more important. The vacuum circuit breaker has minimum pollution to the environment. The vacuum interrupter is the key part of a vacuum circuit breaker. The interrupting characteristics in vacuum and arc-controlling technique are the main problems to be solved for a longer gap distance in developing high voltage vacuum interrupters. To understand the vacuum arc characteristics and provide effective technique to control vacuum arc in a long gap distance, the arc mode transition of a cup-type axial magnetic field electrode is observed by a high-speed charge coupled device (CCD) video camera under different gap distances while the arc voltage and arc current are recorded. The controlling ability of the axial magnetic field on vacuum arc obviously decreases when the gap distance is longer than 40 mm. The noise components and mean value of the arc voltage significantly increase. The effective method for controlling the vacuum arc characteristics is provided by long gap distances based on the test results. The test results can be used as a reference to develop high voltage and large capacity vacuum interrupters

  12. Effect of gap distance on tensile strength of preceramic base metal solder joints.

    Science.gov (United States)

    Fattahi, Farnaz; Motamedi, Milad

    2011-01-01

    In order to fabricate prostheses with high accuracy and durability, soldering techniques have been introduced to clinical dentistry. However, these prostheses always fail at their solder joints. The purpose of this study was to evaluate the effect of gap distance on the tensile strength of base metal solder joints. Based on ADA/ISO 9693 specifications for tensile test, 40 specimens were fabricated from a Ni-Cr alloy and cut at the midpoint of 3-mm diameter bar and placed at desired positions by a specially designed device. The specimens were divided into four groups of 10 samples according to the desired solder gap distance: Group1: 0.1mm; Group2: 0.25mm; Group3: 0.5mm; and Group4: 0.75mm. After soldering, specimens were tested for tensile strength by a universal testing machine at a cross-head speed of 0.5mm/min with a preload of 10N. The mean tensile strength values of the groups were 162, 307.8, 206.1 and 336.7 MPa, respectively. The group with 0.75-mm gap had the highest and the group with 0.1-mm gap had the lowest tensile strength. Bonferroni test showed that Group1 and Group4 had statistically different values (P=0.023), but the differences between other groups were not sig-nificant at a significance level of 0.05. There was no direct relationship between increasing soldering gap distance and tensile strength of the solder joints.

  13. Effects of successive critical distances in heavy ion fusion reactions

    International Nuclear Information System (INIS)

    Lee, S.M.; Nakagawa, T.; Matsuse, T.

    1984-01-01

    The concept of Successive Critical Distances is presented. It appears that whether the fusion cross section is limited by compound nucleus or entrance channel properties depends on the degree of asymmetry of the fusing nuclei. Only in the near to symmetry case does the Statistical Yrast Line emerge as a limiting factor. Otherwise, the critical angular momentum for fusion is restricted by a critical distance

  14. Development of critical thinking skills through distance learning in ...

    African Journals Online (AJOL)

    Interpersonal contact between the lecturers and students improves the development of critical thinking skills. The process is hampered by the geographical distance between the lecturers and the students in the case of distance education and learning. In many cases distance learning is, however, the only option.

  15. The Speaker Gender Gap at Critical Care Conferences.

    Science.gov (United States)

    Mehta, Sangeeta; Rose, Louise; Cook, Deborah; Herridge, Margaret; Owais, Sawayra; Metaxa, Victoria

    2018-06-01

    To review women's participation as faculty at five critical care conferences over 7 years. Retrospective analysis of five scientific programs to identify the proportion of females and each speaker's profession based on conference conveners, program documents, or internet research. Three international (European Society of Intensive Care Medicine, International Symposium on Intensive Care and Emergency Medicine, Society of Critical Care Medicine) and two national (Critical Care Canada Forum, U.K. Intensive Care Society State of the Art Meeting) annual critical care conferences held between 2010 and 2016. Female faculty speakers. None. Male speakers outnumbered female speakers at all five conferences, in all 7 years. Overall, women represented 5-31% of speakers, and female physicians represented 5-26% of speakers. Nursing and allied health professional faculty represented 0-25% of speakers; in general, more than 50% of allied health professionals were women. Over the 7 years, Society of Critical Care Medicine had the highest representation of female (27% overall) and nursing/allied health professional (16-25%) speakers; notably, male physicians substantially outnumbered female physicians in all years (62-70% vs 10-19%, respectively). Women's representation on conference program committees ranged from 0% to 40%, with Society of Critical Care Medicine having the highest representation of women (26-40%). The female proportions of speakers, physician speakers, and program committee members increased significantly over time at the Society of Critical Care Medicine and U.K. Intensive Care Society State of the Art Meeting conferences (p gap at critical care conferences, with male faculty outnumbering female faculty. This gap is more marked among physician speakers than those speakers representing nursing and allied health professionals. Several organizational strategies can address this gender gap.

  16. Nonlinear gap junctions enable long-distance propagation of pulsating calcium waves in astrocyte networks.

    Directory of Open Access Journals (Sweden)

    Mati Goldberg

    Full Text Available A new paradigm has recently emerged in brain science whereby communications between glial cells and neuron-glia interactions should be considered together with neurons and their networks to understand higher brain functions. In particular, astrocytes, the main type of glial cells in the cortex, have been shown to communicate with neurons and with each other. They are thought to form a gap-junction-coupled syncytium supporting cell-cell communication via propagating Ca(2+ waves. An identified mode of propagation is based on cytoplasm-to-cytoplasm transport of inositol trisphosphate (IP(3 through gap junctions that locally trigger Ca(2+ pulses via IP(3-dependent Ca(2+-induced Ca(2+ release. It is, however, currently unknown whether this intracellular route is able to support the propagation of long-distance regenerative Ca(2+ waves or is restricted to short-distance signaling. Furthermore, the influence of the intracellular signaling dynamics on intercellular propagation remains to be understood. In this work, we propose a model of the gap-junctional route for intercellular Ca(2+ wave propagation in astrocytes. Our model yields two major predictions. First, we show that long-distance regenerative signaling requires nonlinear coupling in the gap junctions. Second, we show that even with nonlinear gap junctions, long-distance regenerative signaling is favored when the internal Ca(2+ dynamics implements frequency modulation-encoding oscillations with pulsating dynamics, while amplitude modulation-encoding dynamics tends to restrict the propagation range. As a result, spatially heterogeneous molecular properties and/or weak couplings are shown to give rise to rich spatiotemporal dynamics that support complex propagation behaviors. These results shed new light on the mechanisms implicated in the propagation of Ca(2+ waves across astrocytes and the precise conditions under which glial cells may participate in information processing in the brain.

  17. Enrollment in Distance Education Classes Is Associated with Fewer Enrollment Gaps among Nontraditional Undergraduate Students in the US

    Science.gov (United States)

    Pontes, Manuel C. F.; Pontes, Nancy M. H.

    2012-01-01

    The purpose of this research is to determine whether nontraditional undergraduate students in the US who enroll in distance education classes are less likely to have an enrollment gap (enrollment gap=part year enrollment). Previous research has shown that preference for distance education classes is significantly greater among nontraditional than…

  18. An experimental study on critical heat flux in a hemispherical narrow gap

    International Nuclear Information System (INIS)

    Park, R.J.; Lee, S.J.; Kang, K.H.; Kim, J.H.; Kim, S.B.; Kim, H.D.; Jeong, J.H.

    2000-01-01

    An experimental study of CHFG (Critical Heat Flux in Gap) has been performed to investigate the inherent cooling mechanism using distilled water and Freon R-113 in hemispherical narrow gaps. As a separate effect test of the CHFG test, a CCFL (Counter Current Flow Limit) test has been also performed to confirm the mechanism of the CHF in narrow annular gaps with large diameter. The CHFG test results have shown that an increase in the gap thickness leads to an increase in critical power. The pressure effect on the critical power was found to be much milder than predictions by CHF correlations of other studies. In the CCFL experiment, the occurrence of CCFL was correlated with the Wallis parameter, which was assumed to correspond to the critical power in the CHFG experiment. The measured values of critical power in the CHFG tests are much lower than CCFL experimental data and the predictions made by empirical CHF correlations. (author)

  19. Effect of soldering techniques and gap distance on tensile strength of soldered Ni-Cr alloy joint.

    Science.gov (United States)

    Lee, Sang-Yeob; Lee, Jong-Hyuk

    2010-12-01

    The present study was intended to evaluate the effect of soldering techniques with infrared ray and gas torch under different gap distances (0.3 mm and 0.5 mm) on the tensile strength and surface porosity formation in Ni-Cr base metal alloy. Thirty five dumbbell shaped Ni-Cr alloy specimens were prepared and assigned to 5 groups according to the soldering method and the gap distance. For the soldering methods, gas torch (G group) and infrared ray (IR group) were compared and each group was subdivided by corresponding gap distance (0.3 mm: G3 and IR3, 0.5 mm: G5, IR5). Specimens of the experimental groups were sectioned in the middle with a diamond disk and embedded in solder blocks according to the predetermined distance. As a control group, 7 specimens were prepared without sectioning or soldering. After the soldering procedure, a tensile strength test was performed using universal testing machine at a crosshead speed 1 mm/min. The proportions of porosity on the fractured surface were calculated on the images acquired through the scanning electronic microscope. Every specimen of G3, G5, IR3 and IR5 was fractured on the solder joint area. However, there was no significant difference between the test groups (P > .05). There was a negative correlation between porosity formation and tensile strength in all the specimens in the test groups (P tensile strength of joints and porosity formations between the gas-oxygen torch soldering and infrared ray soldering technique or between the gap distance of 0.3 mm and 0.5 mm.

  20. Photothermal modulation of the gap distance in scanning tunneling microscopy

    International Nuclear Information System (INIS)

    Amer, N.M.; Skumanich, A.; Ripple, D.

    1986-01-01

    We have employed the photothermal effect to modulate the gap distance in a tunneling microscope. In this approach, optical heating induces the expansion and buckling of laser-illuminated sample surface. The surface displacement can be modulated over a wide frequency range, and its height (typically <1 A-circle) can be varied by changing the illumination intensity and modulation frequency. This novel method provides an alternative means for performing tunneling spectroscopy and microscopy, and for determining work functions of materials

  1. The influence of fiber thickness, wall thickness and gap distance on the spiral nanofibrous scaffolds for bone tissue engineering

    International Nuclear Information System (INIS)

    Wang Junping; Shah, Ami; Yu Xiaojun

    2011-01-01

    We have developed a 3D nanofibrous spiral scaffold for bone tissue engineering which has shown enhanced cell attachment, proliferation and differentiation compared to traditional cylindrical scaffolds due to the spiral structures and the nanofiber incorporation. Some important parameters of these spiral scaffolds including gap distance, wall thickness and especially fiber thickness are crucial to the performance of the spiral structured scaffolds. In this study, we investigated the fiber thickness, gap distance and wall thickness of the spiral structure on the behavior of osteoblast cells. The human osteoblast cells are seeded on spiral structured scaffolds with various fiber thickness, gap distance and wall thickness and cell attachment, proliferation, differentiation and mineralized matrix deposition on the scaffolds are evaluated. It was found that increasing the thickness of nanofiber layer not only limited the cell infiltration into the scaffolds, but also restrained the osteoblastic cell phenotype development. Moreover, the geometric effect studies indicated that scaffolds with the thinner wall and gap distance 0.2 mm show the best bioactivity for osteoblasts.

  2. Experimental study of critical heat flux in inclined rectangular gap

    International Nuclear Information System (INIS)

    Kim, S.J.; Kim, Y.H.; Noh, S.W.; Suh, K.Y.; Rempe, J.L.; Cheung, F.B.; Kim, S.B.

    2003-01-01

    In the TMI-2 accident, the lower part of the reactor pressure vessel was overheated and then rather rapidly cooled down, as was later found out in a vessel investigation project. This accounted for the possibility of gap cooling feasibility. For this reason, a great deal of investigations was performed to determine the critical heat flux (CHF) from the standpoint of in-vessel retention (IVR). As part of a joint Korean-U.S. International Nuclear Energy Research Initiative (INERI) project, Tests were conducted to examine the critical heat flux (CHF) on the one-dimensional downward heating rectangular channel having a narrow gap by changing the orientation of the copper test heater assembly in a pool of saturated water under the atmospheric pressure. The test parameters include both the gap sizes of 1, 2, 5 and 10 mm, and the surface orientation angles from the downward-facing position (180deg) to the vertical position (90deg), respectively. It was observed that the CHF generally decreases as the surface inclination angle increases and as the gap size decreases. However, in downward-facing position (180deg), somewhat differing results were detected relative to previous reports. For a certain gap size having a similar dimension with vapor layer thickness, more efficient heat transfer was detected and this may be interpreted by characteristic property such as the vapor layer thickness of water. In consistency with several studies reported in the literature, it was found that there exists a transition angle above that the CHF changes with a rapid slope. (author)

  3. Criticality effects of longitudinal gaps in poison for storage/transport casks

    International Nuclear Information System (INIS)

    Wells, A.H.

    1985-01-01

    A series of criticality calculations was performed with the AMPX/KENO system to determine the sensitivity of the NAC S/T cask 31 assembly basket, which is optimized for a design-basis fuel enrichment of 3.7 wt % 235 U, to axial gaps in the boron neutron poison. The results of these calculations show that axial gaps in the boron cause no statistically detectable change in k/sub eff/ until a minimum gap size is reached. The minimum gap size to change k/sub eff/ is dependent on the basket segment length, because a longer segment length results in fewer gaps for a given active fuel length. Longer segment lengths are less sensitive to gaps in the neutron poison. A typical segment length of 12 to 18 in. is projected for a casting of aluminum/boron alloy, indicating that axial gaps in the neutron poison of 1 in. would be acceptable. This gap thickness is much greater than the intersegment gap produced by modern casting techniques. The investigation described here demonstrated that an axial gap in neutron poison is acceptable for basket castings of large storage/transport casks. A precedent for such gaps is the NLI-6502 cask, so a cask basket with intersegment gaps should be licensable

  4. Phonon-induced enhancement of the energy gap and critical current of superconducting aluminum films

    International Nuclear Information System (INIS)

    Seligson, D.; Clarke, J.

    1983-01-01

    Enhancements of the energy gap Δ and the critical current I/sub c/ have been induced in thin superconducting aluminum films near the transition temperature T/sub c/ by pulses of phonons at approximately 9 GHz. In terms of the change in temperature Vertical BardeltaT/T/sub c/Vertical Bar necessary to produce the same enhancement in equilibrium, the gap enhancement increased smoothly with phonon power at fixed temperature and decreasing temperature at fixed phonon power; however, very close to T/sub c/ the enhancement rolled off. At relatively low phonon powers, the data were in good agreement with the theory of Eckern, Schmid, Schmutz, and Schoen, but at higher power levels the data fell markedly below the predictions of the theory. The critical-current enhancements in terms of Vertical BardeltaT/T/sub c/Vertical Bar were always larger than the gap enhancements at the same temperature and phonon power. At fixed phonon power the critical-current enhancements were nearly independent of temperature, except very close to T/sub c/ where the enhancement became small. The inclusion of the nonequilibrium quasiparticle distribution and the kinetic energy of the supercurrent in the theory relating the critical-current enhancement to the gap enhancement did not resolve the discrepancies between the two enhancements. It appears likely that there is an additional mechanism for critical-current enhancement that has not yet been identified

  5. Nanoparticle heterodimers: The role of size and interparticle gap distance on the optical response

    Science.gov (United States)

    Mokkath, Junais Habeeb

    2018-05-01

    Composite plasmonic nanostructures with controlled size, shape and relative arrangement is a subject of significant current research interest. Much of this is stimulated by the prospects by generating enormous near-field enhancements of the surface and interparticle gap regions for potential applications in surface-enhanced spectroscopies. In this manuscript, using time-dependent density functional theory (TDDFT) calculations, we investigate how the optical response in size matched homodimers and size mismatched heterodimers composed of Aluminum modify while varying the size and interparticle gap distances in the sub-nanometer range. Both systems show interesting optical response evolution. In particular, the size mismatched heterodimers show even more complex optical response evolution due to a symmetry-breaking in the system.

  6. Evaluation of notch effects in low cycle fatigue of alloy 718 using critical distances

    Directory of Open Access Journals (Sweden)

    Eriksson Robert

    2018-01-01

    Full Text Available Gas turbine disks contain many notch-like features acting as stress raisers. The fatigue life based on the notch root stress may be overly conservative as the steep stress gradient in front of the notch may give rise to so-called notch support. In the current work, the theory of critical distances was applied to the prediction of the total fatigue life of low cycle fatigued, notched specimens made from alloy 718. The fatigue tests were performed at 450 °C and 550 °C. It was found that, for lives shorter than 5000–10000 cycles, the notched specimens had longer lives than would have been expected based on the notch root strain. For lives longer than 5000–10000 cycles, there were no notch support. The life prediction for notched specimens could be significantly improved by basing the prediction on the strain chosen some distance from the notch (the critical distance. An expression for calculating the critical distance based on the notch root strain was suggested.

  7. Closing the weld gap with laser/mig hybrid welding process

    DEFF Research Database (Denmark)

    Bagger, Claus; Olsen, Flemming Ove; Wiwe, Bjarne David

    2003-01-01

    In this article, laboratory tests are demonstrated that systematically accesses the critical gap distance when welding CMn 2.13 mm steel with a 2.6 kW CO2 laser, combined with a MIG energy source. In the work, the welding speed is varied at gap distances from 0 to 0.8 mm such that the limits...... for obtaining sound welds are identified. The welds are quality assessed according to ISO 13.919-1 and EN25817, transversal hardness measurements are made and the heat input to the workpiece is calculated. The results show that the critical gap is 0.1 mm for a laser weld alone. With hybrid welding, this can...... be increased to 0.6 mm, even at a welding speed of 3.5 m/min. The maximum welding speed with the hybrid process is comparable to laser welding alone, 4.5 m/min. The measured hardness is comparable to MIG welding, and this corresponds to a 33 percent reduction compared to laser welding alone. The heat input...

  8. Phonon-induced enhancements of the energy gap and critical current in superconducting aluminum

    International Nuclear Information System (INIS)

    Seligson, D.

    1983-05-01

    8 to 10 GHz phonons were generated by piezoelectric transduction of a microwave and by means of a quartz delay line, were allowed to enter the aluminum only after the microwaves had long since disappeared. The maximum enhancements detected were [deltaT/T/sub c/] = -0.07, for i/sub c/ and [deltaT/T/sub c/] = -0.03 for Δ. The power- and temperature-dependence (0.82 less than or equal to T/T/sub c/ less than or equal to 0.994) of the enhancements were compared with the prediction of a theory given by Eliashberg. The gap-enhancement was in good agreement with the theory only for low input lower. The critical current measurements are predicted to be in rough agreement with the Δ measurements but this was not observed. The magnitude of the critical current enhancements was typically more than twice the observed gap enhancements. The measured critical current enhancement was relatively independent of temperature whereas the gap enhancement decreased rapidly as the temperature was lowered

  9. A Critical Interpersonal Distance Switches between Two Coordination Modes in Kendo Matches

    Science.gov (United States)

    Okumura, Motoki; Kijima, Akifumi; Kadota, Koji; Yokoyama, Keiko; Suzuki, Hiroo; Yamamoto, Yuji

    2012-01-01

    In many competitive sports, players need to quickly and continuously execute movements that co-adapt to various movements executed by their opponents and physical objects. In a martial art such as kendo, players must be able to skillfully change interpersonal distance in order to win. However, very little information about the task and expertise properties of the maneuvers affecting interpersonal distance is available. This study investigated behavioral dynamics underlying opponent tasks by analyzing changes in interpersonal distance made by expert players in kendo matches. Analysis of preferred interpersonal distances indicated that players tended to step toward and away from their opponents based on two distances. The most preferred distance enabled the players to execute both striking and defensive movements immediately. The relative phase analysis of the velocities at which players executed steps toward and away revealed that players developed anti-phase synchronizations at near distances to maintain safe distances from their opponents. Alternatively, players shifted to in-phase synchronization to approach their opponents from far distances. This abrupt phase-transition phenomenon constitutes a characteristic bifurcation dynamics that regularly and instantaneously occurs between in- and anti-phase synchronizations at a critical interpersonal distance. These dynamics are profoundly affected by the task constraints of kendo and the physical constraints of the players. Thus, the current study identifies the clear behavioral dynamics that emerge in a sport setting. PMID:23284799

  10. The critical distance in laser-induced plasmas: an operative definition

    International Nuclear Information System (INIS)

    Side, D. Delle; Giuffreda, E.; Nassisi, V.

    2016-01-01

    We propose a method to estimate a precise value for the critical distance L cr after which three-body recombination stops to produce charge losses in an expanding laser-induced plasma. We show in particular that the total charge collected has a ''reversed sigmoid'' shape as a function of the target-to-detector distance. Fitting the total charge data with a logistic related function, we could consider as L cr the intercept of the tangent to this curve in its inflection point. Furthermore, this value scales well with theoretical predictions. From the application point of view, this could be of great practical interest, since it provide a reliable way to precisely determine the geometry of the extraction system in Laser Ion Sources.

  11. The critical distance in laser-induced plasmas: an operative definition

    Science.gov (United States)

    Delle Side, D.; Giuffreda, E.; Nassisi, V.

    2016-05-01

    We propose a method to estimate a precise value for the critical distance Lcr after which three-body recombination stops to produce charge losses in an expanding laser-induced plasma. We show in particular that the total charge collected has a ``reversed sigmoid'' shape as a function of the target-to-detector distance. Fitting the total charge data with a logistic related function, we could consider as Lcr the intercept of the tangent to this curve in its inflection point. Furthermore, this value scales well with theoretical predictions. From the application point of view, this could be of great practical interest, since it provide a reliable way to precisely determine the geometry of the extraction system in Laser Ion Sources.

  12. Measurement of critical heat flux in narrow gap with two-dimensional slices

    International Nuclear Information System (INIS)

    Kim, Yong Hoon; Kim, Sung Joong; Noh, Sang Woo; Suh, Kune Y.

    2002-01-01

    A cooling mechanism due to boiling in a gap between the debris crust and the reactor pressure vessel (RPV) wall was proposed for the TMI-2 reactor accident analysis. If there is enough heat transfer through the gap to cool the outer surface of the debris and the inner surface of the wall, the RPV wall may preserve its integrity during a severe core melt accident. If the heat removal through gap cooling relative to the counter-current flow limitation (CCFL) is pronounced, the safety margin of the reactor can be far greater than what had been previously known in the severe accident management arena. Should a severe accident take place, the RPV integrity will be maintained because of the inherent nature of degraded core coolability inside the lower head due to boiling in a narrow gap between the debris crust and the RPV wall. As a defense-in-depth measure, the heat removal capability by gap cooling coupled with external cooling can be examined for the Korean Standard Nuclear Power Plant (KSNPP) and the Advanced Power Reactor 1400MWe (APR1400) in light of the TMI-2 vessel survival. A number of studies were carried out to investigate the complex heat transfer mechanisms for the debris cooling in the lower plenum. However, these heat transfer mechanisms have not been clearly understood yet. The CHFG (Critical Heat Flux in Gap) experiments at KAERI were carried out to develop the critical heat flux (CHF) correlation in a hemispherical gap, which is the upper limit of the heat transfer. According to the CHFG experiments performed with a pool boiling condition, the CHF in a parallel gap was reduced by 1/30 compared with the value measured in the open pool boiling condition. The correlation developed from the CHFG experiment is based on the fact that the CHF in a hemispherical gap is governed by the CCFL and a Kutateladze type CCFL parameter correlates CCFL data well in hemispherical gap geometry. However, the results of the CHFG experiments appear to be limited in their

  13. A micro-gap, air-filled ionisation chamber as a detector for criticality accident dosimetry

    International Nuclear Information System (INIS)

    Murawski, I.; Zielczynski, M.; Gryzinski, M.A.; Golnik, N.

    2014-01-01

    A micro-gap air-filled ionisation chamber was designed for criticality dosimetry. The special feature of the chamber is its very small gap between electrodes of only 0.3 mm. This prevents ion recombination at high dose rates and minimises the influence of gas on secondary particles spectrum. The electrodes are made of polypropylene because of higher content of hydrogen in this material, when compared with soft tissue. The difference between neutron and gamma sensitivity in such chamber becomes practically negligible. The chamber's envelope contains two specially connected capacitors, one for polarising the electrodes and the other for collecting the ionisation charge. Air-filled ionisation chamber with very small gap is a simple dosemeter, which fulfills the most desired properties of criticality accident dosemeters. Short ion collection time is achieved by combination of small gap and relatively high polarising voltage. For the same reason, parasitic recombination of ions in the chamber is negligibly small even at high dose rates. The difference between neutron and gamma sensitivity is small for tissue-equivalent chamber and is expected to become practically negligible when the chamber electrodes are made of polypropylene. Additional capacitor provides a broad measuring range from ∼0.1 Gy up to ∼25 Gy; however, leakage of electrical charge from polarising capacitor has to be observed and taken into account. Periodical re-charging of the device is necessary. Obviously, final test of the device in conditions simulating criticality accident is needed and will be performed as soon as available. (authors)

  14. Phonon-induced enhancements of the energy gap and critical current in superconducting aluminum

    International Nuclear Information System (INIS)

    Seligson, D.

    1983-01-01

    The enhancement of the energy gap, Δ, and critical current, i/sub c/, in superconducting aluminum thin films were under the influence of 8 to 10 GHz phonons. The phonons were generated by piezoelectric transduction of a 1 kW microwave pulse of about 1 μsec duration. By means of a quartz delay line, the phonons were allowed to enter the aluminum only after the microwaves had long since disappeared. The critical current was measured in long narrow Al strips, in which the current flow is 1-dimensional and well described by Ginsburg-Landau theory. To measure Δ the Al film was used as one electrode in a superconductor-insulator-superconductor tunnel junction whose current-voltage characteristic gave Δ directly. For the measurements of i/sub c/, the total critical current was measured in the presence of the phonon perturbation. For the measurements of Δ the change of Δ away from its equilibrium value was measured. In both cases the first measurements of enhancement of these macroscopic variables under phonon irradiation is reported. The gap-enhancement was found to be in good agreement with theory, but only for relatively and surprisingly low input power. The critical current measurements are predicted to be in rough agreement with the Δ measurements but this was not observed

  15. Twisted trees and inconsistency of tree estimation when gaps are treated as missing data - The impact of model mis-specification in distance corrections.

    Science.gov (United States)

    McTavish, Emily Jane; Steel, Mike; Holder, Mark T

    2015-12-01

    Statistically consistent estimation of phylogenetic trees or gene trees is possible if pairwise sequence dissimilarities can be converted to a set of distances that are proportional to the true evolutionary distances. Susko et al. (2004) reported some strikingly broad results about the forms of inconsistency in tree estimation that can arise if corrected distances are not proportional to the true distances. They showed that if the corrected distance is a concave function of the true distance, then inconsistency due to long branch attraction will occur. If these functions are convex, then two "long branch repulsion" trees will be preferred over the true tree - though these two incorrect trees are expected to be tied as the preferred true. Here we extend their results, and demonstrate the existence of a tree shape (which we refer to as a "twisted Farris-zone" tree) for which a single incorrect tree topology will be guaranteed to be preferred if the corrected distance function is convex. We also report that the standard practice of treating gaps in sequence alignments as missing data is sufficient to produce non-linear corrected distance functions if the substitution process is not independent of the insertion/deletion process. Taken together, these results imply inconsistent tree inference under mild conditions. For example, if some positions in a sequence are constrained to be free of substitutions and insertion/deletion events while the remaining sites evolve with independent substitutions and insertion/deletion events, then the distances obtained by treating gaps as missing data can support an incorrect tree topology even given an unlimited amount of data. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Semantic distance as a critical factor in icon design for in-car infotainment systems.

    Science.gov (United States)

    Silvennoinen, Johanna M; Kujala, Tuomo; Jokinen, Jussi P P

    2017-11-01

    In-car infotainment systems require icons that enable fluent cognitive information processing and safe interaction while driving. An important issue is how to find an optimised set of icons for different functions in terms of semantic distance. In an optimised icon set, every icon needs to be semantically as close as possible to the function it visually represents and semantically as far as possible from the other functions represented concurrently. In three experiments (N = 21 each), semantic distances of 19 icons to four menu functions were studied with preference rankings, verbal protocols, and the primed product comparisons method. The results show that the primed product comparisons method can be efficiently utilised for finding an optimised set of icons for time-critical applications out of a larger set of icons. The findings indicate the benefits of the novel methodological perspective into the icon design for safety-critical contexts in general. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. One-dimensional critical heat flux concerning surface orientation and gap size effects

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yong Hoon; Suh, Kune Y. E-mail: kysuh@snu.ac.kr

    2003-12-01

    Tests were conducted to examine the critical heat flux (CHF) on a one-dimensional downward heating rectangular channel having a narrow gap by changing the orientation of the copper test heater assembly in a pool of saturated water under atmospheric pressure. The test parameters include both the gap sizes of 1, 2, 5 and 10 mm, and the surface orientation angles from the downward-facing position (180 deg.) to the vertical position (90 deg.), respectively. Also, the CHF experiments were performed for pool boiling with varying heater surface orientations in the unconfined space at atmospheric pressure using the rectangular test section. It was observed that the CHF generally decreases as the surface inclination angle increases and as the gap size decreases. In consistency with several studies reported in the literature, it was found that there exists a transition angle at which the CHF changes with a rapid slope. An engineering correlation is developed for the CHF during natural convective boiling in the inclined, confined rectangular channels with the aid of dimensional analysis. This correlation agrees with the experimental data of this study within {+-}20%.

  18. Closing Gaps in Open Distance Learning for Theology Students ...

    African Journals Online (AJOL)

    UNISA's policy documents state clearly that the Open Distance Learning (ODL) concept aims to bridge the time, geographical, economic, social, educational and communication distance between student and institution, student and academics, student and courseware as well as student and peers. Blended learning and ...

  19. The role of minimum supply and social vulnerability assessment for governing critical infrastructure failure: current gaps and future agenda

    Directory of Open Access Journals (Sweden)

    M. Garschagen

    2018-04-01

    Full Text Available Increased attention has lately been given to the resilience of critical infrastructure in the context of natural hazards and disasters. The major focus therein is on the sensitivity of critical infrastructure technologies and their management contingencies. However, strikingly little attention has been given to assessing and mitigating social vulnerabilities towards the failure of critical infrastructure and to the development, design and implementation of minimum supply standards in situations of major infrastructure failure. Addressing this gap and contributing to a more integrative perspective on critical infrastructure resilience is the objective of this paper. It asks which role social vulnerability assessments and minimum supply considerations can, should and do – or do not – play for the management and governance of critical infrastructure failure. In its first part, the paper provides a structured review on achievements and remaining gaps in the management of critical infrastructure and the understanding of social vulnerabilities towards disaster-related infrastructure failures. Special attention is given to the current state of minimum supply concepts with a regional focus on policies in Germany and the EU. In its second part, the paper then responds to the identified gaps by developing a heuristic model on the linkages of critical infrastructure management, social vulnerability and minimum supply. This framework helps to inform a vision of a future research agenda, which is presented in the paper's third part. Overall, the analysis suggests that the assessment of socially differentiated vulnerabilities towards critical infrastructure failure needs to be undertaken more stringently to inform the scientifically and politically difficult debate about minimum supply standards and the shared responsibilities for securing them.

  20. The role of minimum supply and social vulnerability assessment for governing critical infrastructure failure: current gaps and future agenda

    Science.gov (United States)

    Garschagen, Matthias; Sandholz, Simone

    2018-04-01

    Increased attention has lately been given to the resilience of critical infrastructure in the context of natural hazards and disasters. The major focus therein is on the sensitivity of critical infrastructure technologies and their management contingencies. However, strikingly little attention has been given to assessing and mitigating social vulnerabilities towards the failure of critical infrastructure and to the development, design and implementation of minimum supply standards in situations of major infrastructure failure. Addressing this gap and contributing to a more integrative perspective on critical infrastructure resilience is the objective of this paper. It asks which role social vulnerability assessments and minimum supply considerations can, should and do - or do not - play for the management and governance of critical infrastructure failure. In its first part, the paper provides a structured review on achievements and remaining gaps in the management of critical infrastructure and the understanding of social vulnerabilities towards disaster-related infrastructure failures. Special attention is given to the current state of minimum supply concepts with a regional focus on policies in Germany and the EU. In its second part, the paper then responds to the identified gaps by developing a heuristic model on the linkages of critical infrastructure management, social vulnerability and minimum supply. This framework helps to inform a vision of a future research agenda, which is presented in the paper's third part. Overall, the analysis suggests that the assessment of socially differentiated vulnerabilities towards critical infrastructure failure needs to be undertaken more stringently to inform the scientifically and politically difficult debate about minimum supply standards and the shared responsibilities for securing them.

  1. Chemical Distances for Percolation of Planar Gaussian Free Fields and Critical Random Walk Loop Soups

    Science.gov (United States)

    Ding, Jian; Li, Li

    2018-06-01

    We initiate the study on chemical distances of percolation clusters for level sets of two-dimensional discrete Gaussian free fields as well as loop clusters generated by two-dimensional random walk loop soups. One of our results states that the chemical distance between two macroscopic annuli away from the boundary for the random walk loop soup at the critical intensity is of dimension 1 with positive probability. Our proof method is based on an interesting combination of a theorem of Makarov, isomorphism theory, and an entropic repulsion estimate for Gaussian free fields in the presence of a hard wall.

  2. Self-distancing improves interpersonal perceptions and behavior by decreasing medial prefrontal cortex activity during the provision of criticism.

    Science.gov (United States)

    Leitner, Jordan B; Ayduk, Ozlem; Mendoza-Denton, Rodolfo; Magerman, Adam; Amey, Rachel; Kross, Ethan; Forbes, Chad E

    2017-04-01

    Previous research suggests that people show increased self-referential processing when they provide criticism to others, and that this self-referential processing can have negative effects on interpersonal perceptions and behavior. The current research hypothesized that adopting a self-distanced perspective (i.e. thinking about a situation from a non-first person point of view), as compared with a typical self-immersed perspective (i.e. thinking about a situation from a first-person point of view), would reduce self-referential processing during the provision of criticism, and in turn improve interpersonal perceptions and behavior. We tested this hypothesis in an interracial context since research suggests that self-referential processing plays a role in damaging interracial relations. White participants prepared for mentorship from a self-immersed or self-distanced perspective. They then conveyed negative and positive evaluations to a Black mentee while electroencephalogram (EEG) was recorded. Source analysis revealed that priming a self-distanced (vs self-immersed) perspective predicted decreased activity in regions linked to self-referential processing (medial prefrontal cortex; MPFC) when providing negative evaluations. This decreased MPFC activity during negative evaluations, in turn, predicted verbal feedback that was perceived to be more positive, warm and helpful. Results suggest that self-distancing can improve interpersonal perceptions and behavior by decreasing self-referential processing during the provision of criticism. © The Author (2016). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

  3. Comparison of GAP-3 and GAP-4 experiments with conduction freezing calculations

    International Nuclear Information System (INIS)

    Sienicki, J.J.; Spencer, B.W.

    1983-01-01

    Experiments GAP-3 and GAP-4 were performed at ANL to investigate the ability of molten fuel to penetrate downward through the narrow channels separating adjacent subassemblies during an LMFBR hypothetical core disruptive accident. Molten fuel-metal mixtures (81% UO 2 , 19% Mo) at an initial temperature of 3470 0 K generated by a thermite reaction were injected downward into 1 m long rectangular test sections (gap thickness = 0.43 cm, channel width = 20.3 cm) initially at 1170 0 K simulating the nominal Clinch River Breeder Reactor intersubassembly gap. In the GAP-3 test, a prolonged reaction time of approx. 15 s resulted in segregation of the metallic Mo and oxidic UO 2 constituents within the reaction vessel prior to injection. Consequently, Mo entered the test section first and froze, forming a complete plug at a penetration distance of 0.18 m. In GAP-4, the reaction time was reduced to approx. 3 s and the constituents remained well mixed upon injection with the result that the leading edge penetration distance increased to 0.35 m. Posttest examination of the cut-open test sections has revealed the existence of stable insulating crusts upon the underlying steel walls with melting and ablation of the walls only very localized

  4. Winter Responses of Forest Birds to Habitat Corridors and Gaps

    Directory of Open Access Journals (Sweden)

    Colleen Cassady St. Clair

    1998-12-01

    Full Text Available Forest fragmentation and habitat loss may disrupt the movement or dispersal of forest-dwelling birds. Despite much interest in the severity of these effects and ways of mitigating them, little is known about actual movement patterns in different habitat types. We studied the movement of wintering resident birds, lured by playbacks of mobbing calls, to compare the willingness of forest birds to travel various distances in continuous forest, along narrow corridors (fencerows, and across gaps in forest cover. We also quantified the willingness of Black-capped Chickadees (Poecile atricapillus to cross gaps when alternative forested detour routes were available. All species were less likely to respond to the calls as distance increased to 200 m, although White-breasted Nuthatches (Sitta carolinensis and Hairy Woodpeckers (Picoides villosus were generally less likely to respond than chickadees and Downy Woodpeckers (P. pubescens. Chickadees were as likely to travel in corridors as in continuous forest, but were less likely to cross gaps as the gap distance increased. The other species were less willing to travel in corridors and gaps relative to forest, and the differences among habitats also increased with distance. For chickadees, gap-crossing decisions in the presence of forested detours varied over the range of distances that we tested, and were primarily influenced by detour efficiency (the length of the shortcut relative to the available detour. Over short distances, birds used forested detours, regardless of their efficiency. As absolute distances increased, birds tended to employ larger shortcuts in the open when detour efficiency was low or initial distance in the open was high, but they limited their distance from the nearest forest edge to 25 m. Thus, chickadees were unwilling to cross gaps of > 50 m when they had forested alternatives, yet they sometimes crossed gaps as large as 200 m when no such choice existed. Our results suggest that

  5. Disrupting the Implementation Gap with Digital Technology in Healthcare Distance Education: Critical Insights from an e-Mentoring Intensional Network Practitioner Research Project

    Science.gov (United States)

    Singh, Gurmit

    2013-01-01

    Effective professional distance education is urgently needed to develop a well-trained workforce and improve impact on healthcare. However, distance education initiatives have had mixed results in improving practice. Often, successful implementation fails to leverage insights on the social and emergent nature of learning in networks. This paper…

  6. Connection between in-plane upper critical field Hc 2 and gap symmetry in layered d -wave superconductors

    Science.gov (United States)

    Wang, Jing-Rong; Liu, Guo-Zhu; Zhang, Chang-Jin

    2016-07-01

    Angle-resolved upper critical field Hc 2 provides an efficient tool to probe the gap symmetry of unconventional superconductors. We revisit the behavior of in-plane Hc 2 in d -wave superconductors by considering both the orbital effect and Pauli paramagnetic effect. After carrying out systematic analysis, we show that the maxima of Hc 2 could be along either nodal or antinodal directions of a d -wave superconducting gap, depending on the specific values of a number of tuning parameters. This behavior is in contrast to the common belief that the maxima of in-plane Hc 2 are along the direction where the superconducting gap takes its maximal value. Therefore, identifying the precise d -wave gap symmetry through fitting experiments results of angle-resolved Hc 2 with model calculations at a fixed temperature, as widely used in previous studies, is difficult and practically unreliable. However, our extensive analysis of angle-resolved Hc 2 show that there is a critical temperature T*: in-plane Hc 2 exhibits its maxima along nodal directions at T change as other parameters vary, but the existence of π /4 shift of Hc 2 at T* appears to be a general feature. Thus a better method to identify the precise d -wave gap symmetry is to measure Hc 2 at a number of different temperatures, and examine whether there is a π /4 shift in its angular dependence at certain T*. We further show that Landau level mixing does not change this general feature. However, in the presence of Fulde-Ferrell-Larkin-Ovchinnikov state, the angular dependence of Hc 2 becomes quite complicated, which makes it more difficult to determine the gap symmetry by measuring Hc 2. Our results indicate that some previous studies on the gap symmetry of CeCu2Si2 are unreliable and need to be reexamined, and also provide a candidate solution to an experimental discrepancy in the angle-resolved Hc 2 in CeCoIn5.

  7. The critical power that can be removed through a hemispherical narrow gap

    International Nuclear Information System (INIS)

    Jeong, J. H.; Park, R. J.; Kang, K. H.; Kim, S. B.; Kim, H. D.

    1998-01-01

    KAERI launched a research program named SONATA-IV (Simulation Of Naturally Arrested Thermal Attack In Vessel) to investigate the possibility of in-vessel debris cooling through a narrow gap that can be formed between reactor pressure vessel and relocated corium. The CHFG (Critical Heat Flux in Gap) experiments, one of the major experiments of the program, are being carried out. The purpose of the CHFG experiments is to assess the heat removal capacity through a hemispherical narrow gap. The experiments were performed using distilled water and the measurements were made in the range of 1 to 5 atm. The dryout of the heater surface is detected using 66 K-type thermocouples embedded in a heated copper shell. Even if local dryout occurs, there exists a quasi-steady state and the temperature of the dryout region is limited within a certain value. When the heater power is large enough, however, there is no quasi-steady state. The dryout region expands by itself without an increase in heater power and the temperature of the heater surface monotonically increase. Temperature measurements over the heater surface show that the two-phase flow behaviour inside the gaps could be quite different from the other usual CHF experiments. The temperature of the local dryout region is much lower than the minimum film boiling temperature that is measured under the pool boiling condition. The cause seems to be the excellent heat conduction of the copper shell. In order to verify this, numerical heat transfer analysis was performed on the copper shell. The results of the analysis supports the postulate. The measured global dryout points are lower than the predictions by existing empirical CHF correlations based on the data measured with small-scale horizontal plates and verical annulus

  8. Transformation of the superconducting gap to an insulating pseudogap at a critical hole density in the cuprates

    Science.gov (United States)

    Liu, Ye-Hua; Wang, Wan-Sheng; Wang, Qiang-Hua; Zhang, Fu-Chun; Rice, T. M.

    2017-07-01

    We apply the recent wave-packet formalism developed by Ossadnik to describe the origin of the short-range ordered pseudogap state as the hole doping is lowered through a critical density in cuprates. We argue that the energy gain that drives this precursor state to Mott localization, follows from maximizing umklapp scattering near the Fermi energy. To this end, we show how energy gaps driven by umklapp scattering can open on an appropriately chosen surface, as proposed earlier by Yang, Rice, and Zhang. The key feature is that the pairing instability includes umklapp scattering, leading to an energy gap not only in the single-particle spectrum but also in the pair spectrum. As a result the superconducting gap at overdoping is turned into an insulating pseudogap in the antinodal parts of the Fermi surface.

  9. A CRITICAL REVIEW OF INSTRUCTIONAL DESIGN PROCESS OF DISTANCE LEARNING SYSTEM

    Directory of Open Access Journals (Sweden)

    Muhammad Ajmal CHAUDRY

    2010-07-01

    Full Text Available Instructional design refers to planning, development, delivery and evaluation of instructional system. It is an applied field of study aiming at the application of descriptive research outcomes in regular instructional settings. The present study was designed to critically review the process of instructional design at Allama Iqbal Open University (AIOU. It was survey study. Population of the study consisted of 120 academicians of different academic department of AIOU. Survey was conducted through questionnaire for academic staff. It was revealed that need assessment is not done before conceiving the outlines of a course. Also the course did not contain sufficient activities, picture and illustrations. It was also found that did not confirm the course objectives. The study recommended that proper of the course writers for distance learning may be arranged.

  10. Deep Multimodal Distance Metric Learning Using Click Constraints for Image Ranking.

    Science.gov (United States)

    Yu, Jun; Yang, Xiaokang; Gao, Fei; Tao, Dacheng

    2017-12-01

    How do we retrieve images accurately? Also, how do we rank a group of images precisely and efficiently for specific queries? These problems are critical for researchers and engineers to generate a novel image searching engine. First, it is important to obtain an appropriate description that effectively represent the images. In this paper, multimodal features are considered for describing images. The images unique properties are reflected by visual features, which are correlated to each other. However, semantic gaps always exist between images visual features and semantics. Therefore, we utilize click feature to reduce the semantic gap. The second key issue is learning an appropriate distance metric to combine these multimodal features. This paper develops a novel deep multimodal distance metric learning (Deep-MDML) method. A structured ranking model is adopted to utilize both visual and click features in distance metric learning (DML). Specifically, images and their related ranking results are first collected to form the training set. Multimodal features, including click and visual features, are collected with these images. Next, a group of autoencoders is applied to obtain initially a distance metric in different visual spaces, and an MDML method is used to assign optimal weights for different modalities. Next, we conduct alternating optimization to train the ranking model, which is used for the ranking of new queries with click features. Compared with existing image ranking methods, the proposed method adopts a new ranking model to use multimodal features, including click features and visual features in DML. We operated experiments to analyze the proposed Deep-MDML in two benchmark data sets, and the results validate the effects of the method.

  11. Soft Coulomb gap and asymmetric scaling towards metal-insulator quantum criticality in multilayer MoS2.

    Science.gov (United States)

    Moon, Byoung Hee; Bae, Jung Jun; Joo, Min-Kyu; Choi, Homin; Han, Gang Hee; Lim, Hanjo; Lee, Young Hee

    2018-05-24

    Quantum localization-delocalization of carriers are well described by either carrier-carrier interaction or disorder. When both effects come into play, however, a comprehensive understanding is not well established mainly due to complexity and sparse experimental data. Recently developed two-dimensional layered materials are ideal in describing such mesoscopic critical phenomena as they have both strong interactions and disorder. The transport in the insulating phase is well described by the soft Coulomb gap picture, which demonstrates the contribution of both interactions and disorder. Using this picture, we demonstrate the critical power law behavior of the localization length, supporting quantum criticality. We observe asymmetric critical exponents around the metal-insulator transition through temperature scaling analysis, which originates from poor screening in insulating regime and conversely strong screening in metallic regime due to free carriers. The effect of asymmetric scaling behavior is weakened in monolayer MoS 2 due to a dominating disorder.

  12. Probing Critical Point Energies of Transition Metal Dichalcogenides: Surprising Indirect Gap of Single Layer WSe 2

    KAUST Repository

    Zhang, Chendong; Chen, Yuxuan; Johnson, Amber; Li, Ming-yang; Li, Lain-Jong; Mende, Patrick C.; Feenstra, Randall M.; Shih, Chih Kang

    2015-01-01

    By using a comprehensive form of scanning tunneling spectroscopy, we have revealed detailed quasi-particle electronic structures in transition metal dichalcogenides, including the quasi-particle gaps, critical point energy locations, and their origins in the Brillouin zones. We show that single layer WSe surprisingly has an indirect quasi-particle gap with the conduction band minimum located at the Q-point (instead of K), albeit the two states are nearly degenerate. We have further observed rich quasi-particle electronic structures of transition metal dichalcogenides as a function of atomic structures and spin-orbit couplings. Such a local probe for detailed electronic structures in conduction and valence bands will be ideal to investigate how electronic structures of transition metal dichalcogenides are influenced by variations of local environment.

  13. Probing Critical Point Energies of Transition Metal Dichalcogenides: Surprising Indirect Gap of Single Layer WSe 2

    KAUST Repository

    Zhang, Chendong

    2015-09-21

    By using a comprehensive form of scanning tunneling spectroscopy, we have revealed detailed quasi-particle electronic structures in transition metal dichalcogenides, including the quasi-particle gaps, critical point energy locations, and their origins in the Brillouin zones. We show that single layer WSe surprisingly has an indirect quasi-particle gap with the conduction band minimum located at the Q-point (instead of K), albeit the two states are nearly degenerate. We have further observed rich quasi-particle electronic structures of transition metal dichalcogenides as a function of atomic structures and spin-orbit couplings. Such a local probe for detailed electronic structures in conduction and valence bands will be ideal to investigate how electronic structures of transition metal dichalcogenides are influenced by variations of local environment.

  14. Gap Acceptance Behavior Model for Non-signalized

    OpenAIRE

    Fajaruddin Bin Mustakim

    2015-01-01

    The paper proposes field studies that were performed to determine the critical gap on the multiple rural roadways Malaysia, at non-signalized T-intersection by using The Raff and Logic Method. Critical gap between passenger car and motorcycle have been determined.   There are quite number of studied doing gap acceptance behavior model for passenger car however still few research on gap acceptance behavior model for motorcycle. Thus in this paper, logistic regression models were developed to p...

  15. Critical behavior of the Higgs- and Goldstone-mass gaps for the two-dimensional S=1 XY model

    Directory of Open Access Journals (Sweden)

    Yoshihiro Nishiyama

    2015-08-01

    Full Text Available Spectral properties for the two-dimensional quantum S=1 XY model were investigated with the exact diagonalization method. In the symmetry-broken phase, there appear the massive Higgs and massless Goldstone excitations, which correspond to the longitudinal and transverse modes of the spontaneous magnetic moment, respectively. The former excitation branch is embedded in the continuum of the latter, and little attention has been paid to the details, particularly, in proximity to the critical point. The finite-size-scaling behavior is improved by extending the interaction parameters. An analysis of the critical amplitude ratio for these mass gaps is made.

  16. Stochastic and deterministic models to evaluate the critical distance of a near surface repository for the disposal of intermediate and low level radioactive wastes

    Energy Technology Data Exchange (ETDEWEB)

    Alves, A.S.M., E-mail: asergi@eletronuclear.gov.br [Eletrobrás Termonuclear – Eletronuclear S.A. , Rua da Candelária 65, 7° andar, GSN.T, 20091-906 Rio de Janeiro, RJ (Brazil); Melo, P.F. Frutuoso e, E-mail: frutuoso@nuclear.ufrj.br [Graduate Program of Nuclear Engineering, COPPE, Federal University of Rio de Janeiro, Av. Horácio Macedo 2030, Bloco G, sala 206, 21941-914 Rio de Janeiro, RJ (Brazil); Passos, E.M., E-mail: epassos@eletronuclear.gov.br [Eletrobrás Termonuclear – Eletronuclear S.A. , Rua da Candelária 65, 7° andar, GSN.T, 20091-906 Rio de Janeiro, RJ (Brazil); Fontes, G.S., E-mail: gsfontes@hotmail.com [Instituto Militar de Engenharia – IME, Praça General Tibúrcio 80, 22290-270 Rio de Janeiro, RJ (Brazil)

    2015-06-15

    Highlights: • The water infiltration scenario is evaluated for a near surface repository. • The main objective is the determination of the critical distance of the repository. • The column liquid height in the repository is governed by an Ito stochastic equation. • Practical results are obtained for the Abadia de Goiás repository in Brazil. - Abstract: The aim of this paper is to present the stochastic and deterministic models developed for the evaluation of the critical distance of a near surface repository for the disposal of intermediate (ILW) and low level (LLW) radioactive wastes. The critical distance of a repository is defined as the distance between the repository and a well in which the water activity concentration is able to cause a radiological dose to a member of the public equal to the dose limit set by the regulatory body. The mathematical models are developed based on the Richards equation for the liquid flow in the porous media and on the solute transport equation in this medium. The release of radioactive material from the repository to the environment is considered through its base and its flow is determined by Darcy's Law. The deterministic model is obtained from the stochastic approach by neglecting the influence of the Gaussian white noise on the rainfall and the equations are solved analytically with the help of conventional calculus (non-stochastic calculus). The equations of the stochastic model are solved analytically based on the Ito stochastic calculus and numerically by using the Euler–Maruyama method. The impact on the value of the critical distance of the Abadia de Goiás repository is analyzed, taken as a study case, when the deterministic methodology is replaced by the stochastic one, considered more appropriate for modeling rainfall as a stochastic process.

  17. impairs gap junction function causing congenital cataract

    Indian Academy of Sciences (India)

    Navya

    2017-03-24

    Mar 24, 2017 ... experiment showed a lower dye diffusion distance of Cx46 V44M cells, ... Studies of connexins show that channel gating and permeability .... have found that connexin assembled into gap junction plaques is not soluble in 1% ..... high glucose reduces gap junction activity in microvascular endothelial cells.

  18. Critical heat flux analysis on change of plate temperature and cooling water flow rate for rectangular narrow gap with bilateral-heated cases

    International Nuclear Information System (INIS)

    M Hadi Kusuma; Mulya Juarsa; Anhar Riza Antariksawan

    2013-01-01

    Boiling heat transfer phenomena on rectangular narrow gap was related to the safety of nuclear reactors. Research done in order to study the safety of nuclear reactors in particular relating to boiling heat transfer and useful on the improvement of next-generation reactor designs. The research focused on calculation of the heat flux during the cooling process in rectangular narrow gap size 1.0 mm. with initial temperatures 200°C. 400°C, and 600°C, also the flow rates of cooling water 0,1 liters/second. 0,2 liters/second. and 0,3 liters/second. Experiments carried out by injecting water at a certain flow rate with the water temperature 85°C. Transient temperature measurement data recorded by the data acquisition system. Transient temperature measurement data is used to calculate the flux of heat gain is then used to obtain the heat transfer coefficient. This research aimed to obtain the correlation between critical heat flux and heat transfer coefficient to changes in temperatures and water flow rates for bilaterally-heated cases on rectangular narrow gap. The results obtained for a constant cooling water flow rate, critical heat flux will increase when hot plate temperature also increased. While on a constant hot plate temperature, coefficient heat transfer will increase when cooling water flow rate also increased. Thus it can be said that the cooling water flow rate and temperature of the hot plate has a significant effect on the critical heat flux and heat transfer coefficient resulted in quenching process of vertical rectangular narrow gap with double-heated cases. (author)

  19. impairs gap junction function causing congenital cataract

    Indian Academy of Sciences (India)

    LIJUAN CHEN

    2017-12-20

    Dec 20, 2017 ... showed a lower dye diffusion distance of Cx46 V44M cells, which indicates that the gap junction intercellular ... permeability could be affected by alterations of charged residues of .... bled into gap junction plaques is not soluble in 1% Triton ..... regulation of connexin 43 expression by high glucose reduces.

  20. Critical examination of logical formulations in quantum theory. Statistical inference and Hilbertian distance between quantum states

    International Nuclear Information System (INIS)

    Hadjisawas, Nicolas.

    1982-01-01

    After a critical study of the logical quantum mechanics formulations of Jauch and Piron, classical and quantum versions of statistical inference are studied. In order to do this, the significance of the Jaynes and Kulback principles (maximum likelihood, least squares principles) is revealed from the theorems established. In the quantum mechanics inference problem, a ''distance'' between states is defined. This concept is used to solve the quantum equivalent of the classical problem studied by Kulback. The ''projection postulate'' proposition is subsequently deduced [fr

  1. Distance Education and Women Empowerment: The Women Who Dared at Distance Learning Institute

    Science.gov (United States)

    Okunuga, A. O.

    2011-01-01

    In the past, the African female child had always been denied formal education due to various cultural and social prejudices. Distance education has been employed by numerous women, who had earlier thus been deprived, to bridge the educational gap between males and females in the country. These are mature females, of which the majority (54%) are…

  2. Geodesic distance in planar graphs

    International Nuclear Information System (INIS)

    Bouttier, J.; Di Francesco, P.; Guitter, E.

    2003-01-01

    We derive the exact generating function for planar maps (genus zero fatgraphs) with vertices of arbitrary even valence and with two marked points at a fixed geodesic distance. This is done in a purely combinatorial way based on a bijection with decorated trees, leading to a recursion relation on the geodesic distance. The latter is solved exactly in terms of discrete soliton-like expressions, suggesting an underlying integrable structure. We extract from this solution the fractal dimensions at the various (multi)-critical points, as well as the precise scaling forms of the continuum two-point functions and the probability distributions for the geodesic distance in (multi)-critical random surfaces. The two-point functions are shown to obey differential equations involving the residues of the KdV hierarchy

  3. Gap Dependent Bifurcation Behavior of a Nano-Beam Subjected to a Nonlinear Electrostatic Pressure

    Directory of Open Access Journals (Sweden)

    Mohammad Fathalilou

    Full Text Available This paper presents a study on the gap dependent bifurcation behavior of an electro statically-actuated nano-beam. The sizedependent behavior of the beam was taken into account by applying the couple stress theory. Two small and large gap distance regimes have been considered in which the intermolecular vdW and Casimir forces are dominant, respectively. It has been shown that changing the gap size can affect the fundamental frequency of the beam. The bifurcation diagrams for small gap distance revealed that by changing the gap size, the number and type of the fixed points can change. However, for large gap regime, where the Casimir force is the dominant intermolecular force, changing the gap size does not affect the quality of the bifurcation behavior.

  4. A novel reformulation of the Theory of Critical Distances to design notched metals against dynamic loading

    International Nuclear Information System (INIS)

    Yin, T.; Tyas, A.; Plekhov, O.; Terekhina, A.; Susmel, L.

    2015-01-01

    Highlights: • The proposed method is successful in estimating dynamic strength of metals. • The critical distance varies as the loading/strain/displacement rate increases. • The reference strength varies as the loading/strain/displacement rate increases. • This method is recommended to be used with safety factors larger than 1.25. - Abstract: In the present study the linear-elastic Theory of Critical Distances (TCD) is reformulated to make it suitable for predicting the strength of notched metallic materials subjected to dynamic loading. The accuracy and reliability of the proposed reformulation of the TCD was checked against a number of experimental results generated by testing, under different loading/strain rates, notched cylindrical samples of aluminium alloy 6063-T5, titanium alloy Ti–6Al–4V, aluminium alloy AlMg6, and an AlMn alloy. To further validate the proposed design method also different data sets taken from the literature were considered. Such an extensive validation exercise allowed us to prove that the proposed reformulation of the TCD is successful in predicting the dynamic strength of notched metallic materials, this approach proving to be capable of estimates falling within an error interval of ±20%. Such a high level of accuracy is certainly remarkable, especially in light of the fact that it was reached without the need for explicitly modelling the stress vs. strain dynamic behaviour of the investigated ductile metals

  5. Experimental determination of thermal conductivity and gap conductance of fuel rod for HTGR

    International Nuclear Information System (INIS)

    Kikuchi, Teruo; Iwamoto, Kazumi; Ikawa, Katsuichi; Ishimoto, Kiyoshi

    1985-01-01

    The thermal conductivity of fuel compacts and the gap conductance between the fuel compact and the graphite sleeve in fuel rods for a high-temperature gas-cooled reactor (HTGR) were measured by the center heating method. These measurements were made as functions of volume percent particle loading and temperature for thermal conductivity and as functions of gap distance and gas composition for gap conductance. The thermal conductivity of fuel compacts decreases with increasing temperature and with increasing particle loading. The gap conductance increases with increasing temperature and decrease with increasing gap distance. A good gap conductance was observed with helium fill gas. It was seen that the gap conductance was dependent on the thermal conductivity of fill gas and conductance by radiation and could be neglected the conductance through solid-solid contact points of fuel compact and graphite sleeve. (author)

  6. Tensile-strain effect of inducing the indirect-to-direct band-gap transition and reducing the band-gap energy of Ge

    Energy Technology Data Exchange (ETDEWEB)

    Inaoka, Takeshi, E-mail: inaoka@phys.u-ryukyu.ac.jp; Furukawa, Takuro; Toma, Ryo; Yanagisawa, Susumu [Department of Physics and Earth Sciences, Faculty of Science, University of the Ryukyus, 1 Senbaru, Nishihara, Okinawa 903-0213 (Japan)

    2015-09-14

    By means of a hybrid density-functional method, we investigate the tensile-strain effect of inducing the indirect-to-direct band-gap transition and reducing the band-gap energy of Ge. We consider [001], [111], and [110] uniaxial tensility and (001), (111), and (110) biaxial tensility. Under the condition of no normal stress, we determine both normal compression and internal strain, namely, relative displacement of two atoms in the primitive unit cell, by minimizing the total energy. We identify those strain types which can induce the band-gap transition, and evaluate the critical strain coefficient where the gap transition occurs. Either normal compression or internal strain operates unfavorably to induce the gap transition, which raises the critical strain coefficient or even blocks the transition. We also examine how each type of tensile strain decreases the band-gap energy, depending on its orientation. Our analysis clearly shows that synergistic operation of strain orientation and band anisotropy has a great influence on the gap transition and the gap energy.

  7. Leadership Curricula in Nursing Education: A Critical Literature Review and Gap Analysis.

    Science.gov (United States)

    Morrow, Kelly J

    2015-07-01

    The Institute of Medicine's Future of Nursing report advises nursing education programs to integrate and embed leadership content within all areas of prelicensure nursing curriculum. This critical literature review synthesizes the state of the science of leadership curricula in prelicensure baccalaureate nursing education programs from 2008 to 2013. Gaps are identified and discussed. The Academic Search Premier and Health Source databases were searched, using the keywords baccalaureate nursing education and leadership. The CINAHL database was searched, using the keywords leadership, education, nursing, and baccalaureate. The 13 peer-reviewed articles identified for inclusion comprised descriptive articles (n = 8), mixed-methods studies (n = 2), quantitative studies (n = 2), and a qualitative study (n = 1). The underlying theme identified is the study and use of active learning strategies. Subthemes within this context were the use of reflection, peer learning, interdisciplinary teams, organizational partnerships, and curricular reform. Copyright 2015, SLACK Incorporated.

  8. Evolution of the two-gap nature revealed in the upper critical field of Mg1-xAlxB2

    International Nuclear Information System (INIS)

    Kim, Heon-Jung; Lee, Hyun-Sook; Park, Min-Seok; Lee, H.-G.; Jo, Younghun; Jung, Myung-Hwa; Lee, Sung-Ik; Kang, Byeongwon

    2007-01-01

    The temperature and the angular dependences of the upper critical field [H c2 (T,θ)] of Mg 1-x Al x B 2 single crystals (x=0.12 and 0.21) were studied. The H c2 (T,θ) was found to be well described by the dirty-limit two-gap theory. A quantitative comparison of the data with this theory indicated that Mg 1-x Al x B 2 single crystals preserved the two-gap nature but became dirtier. We also found that as the Al concentration was increased, anisotropic impurity scattering increased, making the σ bands less anisotropic. In addition, these results are compared with those of 10% C-doped MgB 2 single crystals

  9. Closing the Gap: Opportunities for Distance Education to Benefit Adult Learners in Higher Education

    Science.gov (United States)

    Carlsen, A.; Holmberg, C.; Neghina, C.; Owusu-Boampong, A.

    2016-01-01

    Distance education in higher education is a fast-growing and widespread phenomenon. As many adults are unable to participate in on-campus education, distance education offers flexible learning paths that greatly enhance accessibility to higher education. Exploring distance education's potential to increase the participation of adult learners in…

  10. Critical gaps in the medical knowledge base of eating disorders.

    Science.gov (United States)

    Gibson, Dennis; Drabkin, Anne; Krantz, Mori J; Mascolo, Margherita; Rosen, Elissa; Sachs, Katherine; Welles, Christine; Mehler, Philip S

    2018-04-21

    Eating disorders are unique in that they inherently have much medical comorbidity both as a part of restricting-type eating disorders and those characterized by purging behaviors. Over the last three decades, remarkable progress has been made in the understanding and treatment of the medical complications of eating disorders. Yet, unfortunately, there is much research that is sorely needed to bridge the gap between current medical knowledge and more effective and evidence-based medical treatment knowledge. These gaps exist in many different clinical areas including cardiology, electrolytes, gastrointestinal and bone disease. In this paper, we discuss some of the knowledge gap areas, which if bridged would help develop more effective medical intervention for this population of patients.

  11. Measuring the sustainability of a natural system by using multi-criteria distance function methods: Some critical issues.

    Science.gov (United States)

    Diaz-Balteiro, L; Belavenutti, P; Ezquerro, M; González-Pachón, J; Ribeiro Nobre, S; Romero, C

    2018-05-15

    There is an important body of literature using multi-criteria distance function methods for the aggregation of a battery of sustainability indicators in order to obtain a composite index. This index is considered to be a proxy of the sustainability goodness of a natural system. Although this approach has been profusely used in the literature, it is not exempt from difficulties and potential pitfalls. Thus, in this paper, a significant number of critical issues have been identified showing different procedures capable of avoiding, or at least of mitigating, the inherent potential pitfalls associated with each one. The recommendations made in the paper could increase the theoretical soundness of the multi-criteria distance function methods when this type of approach is applied in the sustainability field, thus increasing the accuracy and realism of the sustainability measurements obtained. Copyright © 2018 Elsevier Ltd. All rights reserved.

  12. Workplace skills and the skills gaps related to employee critical thinking ability and science education curriculum

    Science.gov (United States)

    Alexander, William A.

    In recent years, business and industry have been vocal critics of education. Critics complain the American workforce, particularly young people, are deficient in workplace skills. A survey of 500 randomly selected Ohio businesses was used to determine opinions of respondents related to workplace skills gaps, rising skill levels, and level and type of critical thinking used on the job by all employees and entry-level employees. Four of 18 science outcomes promoted by the Ohio Department of Education had an application in business and these required critical-thinking skills to complete. These four formed the foundation in the survey because they provided a connection between thinking skills required on the Ohio 12 th Grade Proficiency Test and those required on the job. Pearson correlation coefficient was used to identify correlation between responses. The alpha level was p ≤ .05. Stepwise multiple linear regression analysis was conducted to identify significant (p ≤ .05) relationships between variables as represented by responses. In addition, one version of the Science Section of the Ohio 12th Grade Proficiency Test was analyzed for use of critical thinking using the SCAN's critical-thinking attributes as a standard. There were several findings related to workplace skills and critical thinking. Only 17.1% of respondents indicated dissatisfaction with the basic academic skill level of their employees. A majority (71.1%) of responding businesses perceived a lack of work ethic as more important than deficient academic skills. Only 17.1% of respondents reported the skill level of their entry-level employees was rising. Approximately 1/3 of responding businesses required no critical thinking at all from their entry-level employees. Small businesses were significantly more likely to require higher levels of critical thinking from their entry level employees than larger businesses. Employers who reported rising skill levels in entry-level employees required all of

  13. The dependence of the electronic coupling on energy gap and bridge conformation - Towards prediction of the distance dependence of electron transfer reactions

    International Nuclear Information System (INIS)

    Eng, Mattias P.; Albinsson, Bo

    2009-01-01

    The attenuation factor, β, for the distance dependence of electron exchange reactions is a sensitive function of the donor-bridge energy gap and bridge conformation. In this work the electronic coupling for electron and triplet excitation energy transfer has been investigated for five commonly used repeating bridge structures. The investigated bridge structures are OF (oligo fluorene), OP (oligo phenylene), OPE (oligo p-phenyleneethynylene), OPV (oligo phenylenevinylene), and OTP (oligo thiophene). Firstly, the impact of the donor-bridge energy gap was investigated by performing calculations with a variety of donors appended onto bridges that were kept in a planar conformation. This resulted in, to our knowledge, the first presented sets of bridge specific parameters to be inserted into the commonly used McConnell model. Secondly, since at experimental conditions large conformational flexibility is expected, a previously developed model that takes conformational disorder of the bridge into account has been applied to the investigated systems [M.P. Eng, T. Ljungdahl, J. Martensson, B. Albinsson, J. Phys. Chem. B 110 (2006) 6483]. This model is based on Boltzmann averaging and has been shown to describe the temperature dependence of the attenuation factor through OPE-bridges. Together, the parameters describing the donor-bridge energy gap dependence, for planar bridge structures, and the Boltzmann averaging procedure, describing the impact of rotational disorder, have the potential to a priori predict attenuation factors for electron and excitation energy transfer reactions through bridged donor-acceptor systems

  14. Learning from Distance Faculty: A Faculty Needs Assessment at the University of Wyoming

    Science.gov (United States)

    Kvenild, Cassandra; Bowles-Terry, Melissa

    2011-01-01

    Distance educators have special library needs. This article discusses the results of a library needs assessment of distance instructors at the University of Wyoming. Access to resources, use of library instructional services, barriers to distance library use, and perceived gaps in service are all addressed. Follow-up actions, based on survey…

  15. Design of nanostrip magnonic crystal waveguides with a single magnonic band gap

    International Nuclear Information System (INIS)

    Wang, Qi; Zhong, Zhiyong; Jin, Lichuan; Tang, Xiaoli; Bai, Feiming; Zhang, Huaiwu; Beach, Geoffrey S.D.

    2013-01-01

    A novel planar structure of magnonic-crystal waveguide (MCW) with periodic rectangular-shaped holes embedded in a magnetic nanostrip film was designed. The effects of the distance between rectangular-shaped holes in the width direction of MCW on magnonic band structures were studied by micromagnetic simulations. The results show that a MCW with a single magnonic band gap can be obtained by adjusting the distance to meet the condition of Bragg reflection of spin waves in the width direction of MCW. Moreover, the center frequency and width of magnonic gap can be regulated by changing the period and length of rectangular-shaped holes. - Highlights: • Design a novel planar structure of magnonic-crystal waveguide. • The physical origin of a single magnonic band gap. • Study of the center frequency and width of magnonic gap

  16. Morphometry of medial gaps of human brain artery branches.

    Science.gov (United States)

    Canham, Peter B; Finlay, Helen M

    2004-05-01

    The bifurcation regions of the major human cerebral arteries are vulnerable to the formation of saccular aneurysms. A consistent feature of these bifurcations is a discontinuity of the tunica media at the apex of the flow divider. The objective was to measure the 3-dimensional geometry of these medial gaps or "medial defects." Nineteen bifurcations and 2 junctions of human cerebral arteries branches (from 4 male and 2 female subjects) were formalin-fixed at physiological pressure and processed for longitudinal serial sectioning. The apex and adjacent regions were examined and measurements were made from high-magnification photomicrographs, or projection microscope images, of the gap dimensions at multiple levels through the bifurcation. Plots were made of the width of the media as a function of distance from the apex. The media at each edge of the medial gap widened over a short distance, reaching the full width of the media of the contiguous daughter vessel. Medial gap dimensions were compared with the planar angle of the bifurcation, and a strong negative correlation was found, ie, the acute angled branches have the more prominent medial gaps. A discontinuity of the media at the apex was seen in all the bifurcations examined and was also found in the junction regions of brain arteries. We determined that the gap width is continuous with well-defined dimensions throughout its length and average length-to-width ratio of 6.9. The gaps were generally centered on the prominence of the apical ridge.

  17. Energy gap and upper critical field of the new magnetic superconductor Mo3Sb7 found by the Andreev reflection method

    International Nuclear Information System (INIS)

    Dmitriev, V M; Rybaltchenko, L F; Ishchenko, L A; Khristenko, E V; Bukowski, Z; Troc, R

    2006-01-01

    We present the data of the point contact (PC) Andreev-reflection measurements on the new paramagnetic superconductor Mo 3 Sb 7 , which were used for finding the energy gap Δ and upper critical field H c2 for this compound. The maximum gap value, reduced to the zero temperature via the Bardeen-Cooper-Schrieffer (BCS) theory, turned out to be Δ (0) ≅ 0.32 meV, which is slightly smaller than that expected from the BCS theory, Δ BCS (0) ≅ 0.35 meV. The temperature dependence of the gap obeys the BCS theory approximately. The H c2 (0) value of about 16.5 kOe was obtained from fitting the experimental data to the conventional H(T) dependence, which is quadratic in temperature. This value is in close agreement with the result from magnetization measurements of 17.2 kOe

  18. Wide gap semiconductor microwave devices

    International Nuclear Information System (INIS)

    Buniatyan, V V; Aroutiounian, V M

    2007-01-01

    A review of properties of wide gap semiconductor materials such as diamond, diamond-like carbon films, SiC, GaP, GaN and AlGaN/GaN that are relevant to electronic, optoelectronic and microwave applications is presented. We discuss the latest situation and perspectives based on experimental and theoretical results obtained for wide gap semiconductor devices. Parameters are taken from the literature and from some of our theoretical works. The correspondence between theoretical results and parameters of devices is critically analysed. (review article)

  19. Positioning for Effectiveness: Applying Marketing Concepts to Distance Education.

    Science.gov (United States)

    Levenburg, Nancy

    1997-01-01

    Demonstrates how colleges can use distance education to attract and retain a "critical mass" of learners for distance programs. Explores alternative ways to view distance education market opportunities and determine which avenues to pursue. Suggests how to be more effective in all aspects of distance education programs. (13 citations) (YKH)

  20. Bullying and Harassment in Secondary Schools: A Critical Feminist Analysis of the Gaps, Overlaps, and Implications from a Decade of Research

    Science.gov (United States)

    Meyer, Elizabeth J.

    2007-01-01

    This paper presents an analysis of the past decade (1997-2007) of research conducted in the areas of bullying and harassment in secondary schools. The author presents trends in the research as well as addresses the significant gaps left in a field that is heavily influenced by one school thought. By applying a critical feminist lens to this body…

  1. Star junctions and watermelons of pure or random quantum Ising chains: finite-size properties of the energy gap at criticality

    Science.gov (United States)

    Monthus, Cécile

    2015-06-01

    We consider M  ⩾  2 pure or random quantum Ising chains of N spins when they are coupled via a single star junction at their origins or when they are coupled via two star junctions at the their two ends leading to the watermelon geometry. The energy gap is studied via a sequential self-dual real-space renormalization procedure that can be explicitly solved in terms of Kesten variables containing the initial couplings and and the initial transverse fields. In the pure case at criticality, the gap is found to decay as a power-law {ΔM}\\propto {{N}-z(M)} with the dynamical exponent z(M)=\\frac{M}{2} for the single star junction (the case M   =   2 corresponds to z   =   1 for a single chain with free boundary conditions) and z(M)   =   M  -  1 for the watermelon (the case M   =   2 corresponds to z   =   1 for a single chain with periodic boundary conditions). In the random case at criticality, the gap follows the Infinite Disorder Fixed Point scaling \\ln {ΔM}=-{{N}\\psi}g with the same activated exponent \\psi =\\frac{1}{2} as the single chain corresponding to M   =   2, and where g is an O(1) random positive variable, whose distribution depends upon the number M of chains and upon the geometry (star or watermelon).

  2. A Strategic Planning Process Model for Distance Education

    Science.gov (United States)

    Pisel, Kenneth P.

    2008-01-01

    As more institutions seek to implement or expand distance learning programs, it becomes critical to integrate distance learning programs into broader strategic visions and plans. Using the informed opinion from a panel of peer-nominated experts via iterative Delphi questionnaires, a 10-phased strategic planning process model for distance education…

  3. Long-distance entanglement and quantum teleportation in XX spin chains

    International Nuclear Information System (INIS)

    Campos Venuti, L.; Giampaolo, S. M.; Illuminati, F.; Zanardi, P.

    2007-01-01

    Isotropic XX models of one-dimensional spin-1/2 chains are investigated with the aim to elucidate the formal structure and the physical properties that allow these systems to act as channels for long-distance, high-fidelity quantum teleportation. We introduce two types of models: (i) open, dimerized XX chains, and (ii) open XX chains with small end bonds. For both models we obtain the exact expressions for the end-to-end correlations and the scaling of the energy gap with the length of the chain. We determine the end-to-end concurrence and show that model (i) supports true long-distance entanglement at zero temperature, while model (ii) supports 'quasi-long-distance' entanglement that slowly falls off with the size of the chain. Due to the different scalings of the gaps, respectively exponential for model (i) and algebraic in model (ii), we demonstrate that the latter allows for efficient qubit teleportation with high fidelity in sufficiently long chains even at moderately low temperatures

  4. Bridging the gap: The design of bank loan contracts and distance

    NARCIS (Netherlands)

    Hollander, Stephan; Verriest, A.J.M.

    How do the distance constraints faced by lenders in acquiring borrower information affect the design of bank loan contracts? Theoretical studies posit that greater information asymmetry leads to the allocation of stronger ex ante decision rights to the lender (the uninformed party). Consistent with

  5. Bridging the Learning Gap: Cross-Cultural Learning and Teaching through Distance

    Science.gov (United States)

    Mullings, Delores V.

    2015-01-01

    This project engaged students, practitioners, and educators from University of Labor and Social Affairs, Cau Giay District, Hanoi and Newfoundland and Labrador, Canada, in a cross-cultural distance learning and teaching collaboration. Two groups met simultaneously through Skype videoconferencing to discuss and learn about field supervision and…

  6. Simulated front crawl swimming performance related to critical speed and critical power.

    Science.gov (United States)

    Toussaint, H M; Wakayoshi, K; Hollander, A P; Ogita, F

    1998-01-01

    Competitive pool swimming events range in distance from 50 to 1500 m. Given the difference in performance times (+/- 23-1000 s), the contribution of the aerobic and anaerobic energy systems changes considerably with race distance. In training practice the regression line between swimming distance and time (Distance = critical velocity x time + anaerobic swimming capacity) is used to determine the individual capacity of the aerobic and anaerobic metabolic pathways. Although there is confidence that critical velocity and anaerobic swimming capacity are fitness measures that separate aerobic and anaerobic components, a firm theoretical basis for the interpretation of these results does not exist. The purpose of this study was to evaluate the critical power concept and anaerobic swimming capacity as measures of the aerobic and anaerobic capacity using a modeling approach. A systems model was developed that relates the mechanics and energetics involved in front crawl swimming performance. From actual swimming flume measurements, the time dependent aerobic and anaerobic energy release was modeled. Data derived from the literature were used to relate the energy cost of front crawl swimming to swimming velocity. A balance should exist between the energy cost to swim a distance in a certain time and the concomitant aerobic and anaerobic energy release. The ensuing model was used to predict performance times over a range of distances (50-1500 m) and to calculate the regression line between swimming distance and time. Using a sensitivity analysis, it was demonstrated that the critical velocity is indicative for the capacity of the aerobic energy system. Estimates of the anaerobic swimming capacity, however, were influenced by variations in both anaerobic and aerobic energy release. Therefore, it was concluded that the anaerobic swimming capacity does not provide a reliable estimate of the anaerobic capacity.

  7. Making the Invisible Visible: Personas and Mental Models of Distance Education Library Users

    Science.gov (United States)

    Lewis, Cynthia; Contrino, Jacline

    2016-01-01

    Gaps between users' and designers' mental models of digital libraries often result in adverse user experiences. This article details an exploratory user research study at a large, predominantly online university serving non-traditional distance education students with the goal of understanding these gaps. Using qualitative data, librarians created…

  8. Influence of gap length on the field increase factor β of an electrode projection (whisker)

    International Nuclear Information System (INIS)

    Miller, H.C.

    1984-01-01

    β, the increase of the macroscopic electric field at the tip of a projection, varies with the gap length. The sign and magnitude of this variation depends upon how the gap length is defined. If gap length is defined as x, the distance from the projection tip to the opposing electrode, then β is a strong function of x and may be approximated by β(x) = β/sub infinity/x/(x+h) [h = projection height] in the region where x/h>10/β/sub infinity/. If gap length is defined as d, the interelectrode distance ignoring the projection, then β is a weak function of d and may be set equal to β/sub infinity/ in the region d/h>2

  9. Mechanics of Fluid-Filled Interstitial Gaps. II. Gap Characteristics in Xenopus Embryonic Ectoderm.

    Science.gov (United States)

    Barua, Debanjan; Parent, Serge E; Winklbauer, Rudolf

    2017-08-22

    The ectoderm of the Xenopus embryo is permeated by a network of channels that appear in histological sections as interstitial gaps. We characterized this interstitial space by measuring gap sizes, angles formed between adjacent cells, and curvatures of cell surfaces at gaps. From these parameters, and from surface-tension values measured previously, we estimated the values of critical mechanical variables that determine gap sizes and shapes in the ectoderm, using a general model of interstitial gap mechanics. We concluded that gaps of 1-4 μm side length can be formed by the insertion of extracellular matrix fluid at three-cell junctions such that cell adhesion is locally disrupted and a tension difference between cell-cell contacts and the free cell surface at gaps of 0.003 mJ/m 2 is generated. Furthermore, a cell hydrostatic pressure of 16.8 ± 1.7 Pa and an interstitial pressure of 3.9 ± 3.6 Pa, relative to the central blastocoel cavity of the embryo, was found to be consistent with the observed gap size and shape distribution. Reduction of cell adhesion by the knockdown of C-cadherin increased gap volume while leaving intracellular and interstitial pressures essentially unchanged. In both normal and adhesion-reduced ectoderm, cortical tension of the free cell surfaces at gaps does not return to the high values characteristic of the free surface of the whole tissue. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  10. Mind the Gap

    Science.gov (United States)

    Fairbanks, Terry; Savage, Erica; Adams, Katie; Wittie, Michael; Boone, Edna; Hayden, Andrew; Barnes, Janey; Hettinger, Zach; Gettinger, Andrew

    2016-01-01

    Summary Objective Decisions made during electronic health record (EHR) implementations profoundly affect usability and safety. This study aims to identify gaps between the current literature and key stakeholders’ perceptions of usability and safety practices and the challenges encountered during the implementation of EHRs. Materials and Methods Two approaches were used: a literature review and interviews with key stakeholders. We performed a systematic review of the literature to identify usability and safety challenges and best practices during implementation. A total of 55 articles were reviewed through searches of PubMed, Web of Science and Scopus. We used a qualitative approach to identify key stakeholders’ perceptions; semi-structured interviews were conducted with a diverse set of health IT stakeholders to understand their current practices and challenges related to usability during implementation. We used a grounded theory approach: data were coded, sorted, and emerging themes were identified. Conclusions from both sources of data were compared to identify areas of misalignment. Results We identified six emerging themes from the literature and stakeholder interviews: cost and resources, risk assessment, governance and consensus building, customization, clinical work-flow and usability testing, and training. Across these themes, there were misalignments between the literature and stakeholder perspectives, indicating major gaps. Discussion Major gaps identified from each of six emerging themes are discussed as critical areas for future research, opportunities for new stakeholder initiatives, and opportunities to better disseminate resources to improve the implementation of EHRs. Conclusion Our analysis identified practices and challenges across six different emerging themes, illustrated important gaps, and results suggest critical areas for future research and dissemination to improve EHR implementation. PMID:27847961

  11. Giving what one should: explanations for the knowledge-behavior gap for altruistic giving.

    Science.gov (United States)

    Blake, Peter R

    2018-04-01

    Several studies have shown that children struggle to give what they believe that they should: the so-called knowledge-behavior gap. Over a dozen recent Dictator Game studies find that, although young children believe that they should give half of a set of resources to a peer, they typically give less and often keep all of the resources for themselves. This article reviews recent evidence for five potential explanations for the gap and how children close it with age: self-regulation, social distance, theory of mind, moral knowledge and social learning. I conclude that self-regulation, social distance, and social learning show the most promising evidence for understanding the mechanisms that can close the gap. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Functionalizing large nanoparticles for small gaps in dimer nanoantennas

    Science.gov (United States)

    Vietz, Carolin; Lalkens, Birka; Acuna, Guillermo P.; Tinnefeld, Philip

    2016-04-01

    The process of functionalizing gold nanoparticles with DNA commonly competes with nanoparticle aggregation, especially for larger particles of more than 80 nm diameter. Longer DNA strands reduce the tendency for aggregation but commonly lead to larger gaps when applied in certain geometrical arrangements such as gap nanoantennas. Here, we demonstrate that reversing the polarization of one of the strands for hybridization (yielding a zipper-like geometry) is sterically possible with uncompromised yields. Using the single dye molecule’s fluorescence lifetime as an indicator of the proximity of the nanoparticle in combination with electrodynamic simulations, we determine the distance between the nanoparticle and the dye placed in a DNA origami pillar. Importantly, compared to the common shear geometry smaller distances between the connected structures are obtained which are independent of the length of the DNA connector. Using the zipper geometry, we then arranged nanoparticles of 100 and 150 nm diameter on DNA origami and formed gap nanoantennas. We find that the previously reported trend of increased fluorescence enhancement of ATTO647N with increasing particle size for 20-100 nm nanoparticles is stopped. Gap nanoantennas built with 150 nm nanoparticles exhibit smaller enhancement than those with 100 nm nanoparticles. These results are discussed with the aid of electrodynamic simulations.

  13. Influence of gap and overlap paradigms on saccade latencies and vergence eye movements in seven-year-old children.

    Science.gov (United States)

    Bucci, Maria Pia; Pouvreau, Nathalie; Yang, Qing; Kapoula, Zoï

    2005-07-01

    The latency of eye movements is influenced by the fixation task; when the fixation stimulus is switched off before the target presentation (gap paradigm) the latency becomes short and express movements occur. In contrast, when the fixation stimulus remains on when the target appears (overlap paradigm), eye movement latency is longer. Several previous studies have shown increased rates of express saccades in children; however the presence of an express type of latency for vergence and combined movements in children has never been explored. The present study examines the effects of the gap and the overlap paradigms on horizontal saccades at far (150 cm) and at close (20 cm) viewing distances, on vergence along the median plane, and on saccades combined with convergence or divergence in 15 normal seven-year-old children. The results show that the gap paradigm produced shorter latency for all eye movements than the overlap paradigm, but the difference was only significant for saccades at close viewing distances, for divergence (pure and combined), and for saccades combined with vergence. The gap paradigm produced significantly higher rates of express latencies for saccades at close viewing distances, for divergence, and for saccades combined with divergence; in contrast, the frequencies of express latencies for saccades at far viewing distances and for convergence (pure or combined) were similar in the gap and the overlap paradigms. Interestingly, the rate of anticipatory latencies (gap paradigm. Our collective findings suggest that the initiation of saccades at close viewing distances and of divergence is more reflexive, particularly in the gap paradigm. The finding of frequent anticipatory divergence that occurs at similar rates for seven-year-old children (this study) and for adults (Coubard et al., 2004, Exp Brain Res 154:368-381) indicates that predictive initiation of divergence is dominant.

  14. Submerged arc narrow gap welding of the steel DIN 20MnMoNi55

    International Nuclear Information System (INIS)

    Moraes, M.M.

    1987-01-01

    The methodology for submerged arc narrow gap welding for high thickness rolled steel DIN 20MnMoNi55 was developed, using din S3NiMo1 04 mm and 05 mm wires, and DIN 8B435 flux. For this purpose, submerged arc narrow gap welded joints with 50 mm and 120 mm thickness were made aiming the welding parameters optimization and the study of the influence of welding voltage, wire diameter and wire to groove face distance on the operational performance and on the welded joint quality, specially on the ISO-V impact toughness. These welded joints were checked by non-destructive mechanical and metallographic tests. Results were compared with those obtained by one 120 mm thickness submerged arc conventional gap welded joint, using the same base metal and consumables (05 mm wire). The analysis of the results shows that the increasing of the wire to groove face distance and the welding voltage increases the hardness and the ISO-V impact toughness of the weld metal. It shows that the reduction of the gap angle is the main cause for the obtained of a heat affected zone free from coarse grains, the reduction of the welding voltage, the increasing of the wire to groove face distance, and the grounding optimization also contribute for that. It was also concluded that the quality and the execution complexity level of a narrow gap welded joint are identical to a conventional gap welded joint. (author) [pt

  15. Experimental Study on CHF in a Hemispherical Narrow Gap

    International Nuclear Information System (INIS)

    Jeong, J.H.; Park, R.J.; Kang, K.H.; Kim, S.B.; Kim, H.D.

    1999-01-01

    As a part of the SONATA-IV program, KAERI is conducting an experimental investigation of critical heat flux(CHF) in hemispherical narrow gaps. A visualization experiment, VISU-II, was done as the first step to get a visual observation of the flow behaviour inside a hemispherical gap and to understand the CHF-triggering mechanism. It was observed that the counter-current flow limitation (CCFL) phenomenon prevented water from wetting the heater surface and induced CHF. The CHFG (Critical Heat Flux in Gap) test is now being performed to measure the CHF and to investigate the inherent cooling mechanism in hemispherical narrow gaps. Temperature measurements over the heater surface show that the two-phase flow behaviour inside the gaps could be quite different from the other usual CHF experiments. The measured CHF points are lower than the predictions by existing empirical correlations based on the data measured with small-scale horizontal plates and vertical annulus. (authors)

  16. Mind the Civic Empowerment Gap: Economically Elite Students and Critical Civic Education

    Science.gov (United States)

    Swalwell, Katy

    2015-01-01

    Calls to close the civic empowerment gap have traditionally focused on improving and expanding civic education for students in high-poverty urban schools. While important, this recommendation implies that closing the gap is in and of itself a sufficient end and that the civic education of affluent youth is unproblematic. This paper calls for (1)…

  17. A comparison of prognostic significance of strong ion gap (SIG) with other acid-base markers in the critically ill: a cohort study.

    Science.gov (United States)

    Ho, Kwok M; Lan, Norris S H; Williams, Teresa A; Harahsheh, Yusra; Chapman, Andrew R; Dobb, Geoffrey J; Magder, Sheldon

    2016-01-01

    This cohort study compared the prognostic significance of strong ion gap (SIG) with other acid-base markers in the critically ill. The relationships between SIG, lactate, anion gap (AG), anion gap albumin-corrected (AG-corrected), base excess or strong ion difference-effective (SIDe), all obtained within the first hour of intensive care unit (ICU) admission, and the hospital mortality of 6878 patients were analysed. The prognostic significance of each acid-base marker, both alone and in combination with the Admission Mortality Prediction Model (MPM0 III) predicted mortality, were assessed by the area under the receiver operating characteristic curve (AUROC). Of the 6878 patients included in the study, 924 patients (13.4 %) died after ICU admission. Except for plasma chloride concentrations, all acid-base markers were significantly different between the survivors and non-survivors. SIG (with lactate: AUROC 0.631, confidence interval [CI] 0.611-0.652; without lactate: AUROC 0.521, 95 % CI 0.500-0.542) only had a modest ability to predict hospital mortality, and this was no better than using lactate concentration alone (AUROC 0.701, 95 % 0.682-0.721). Adding AG-corrected or SIG to a combination of lactate and MPM0 III predicted risks also did not substantially improve the latter's ability to differentiate between survivors and non-survivors. Arterial lactate concentrations explained about 11 % of the variability in the observed mortality, and it was more important than SIG (0.6 %) and SIDe (0.9 %) in predicting hospital mortality after adjusting for MPM0 III predicted risks. Lactate remained as the strongest predictor for mortality in a sensitivity multivariate analysis, allowing for non-linearity of all acid-base markers. The prognostic significance of SIG was modest and inferior to arterial lactate concentration for the critically ill. Lactate concentration should always be considered regardless whether physiological, base excess or physical-chemical approach

  18. Characterizing the Variable Dust Permeability of Planet-induced Gaps

    Science.gov (United States)

    Weber, Philipp; Benítez-Llambay, Pablo; Gressel, Oliver; Krapp, Leonardo; Pessah, Martin E.

    2018-02-01

    Aerodynamic theory predicts that dust grains in protoplanetary disks will drift radially inward on comparatively short timescales. In this context, it has long been known that the presence of a gap opened by a planet can significantly alter the dust dynamics. In this paper, we carry out a systematic study employing long-term numerical simulations aimed at characterizing the critical particle size for retention outside a gap as a function of particle size, as well as various key parameters defining the protoplanetary disk model. To this end, we perform multifluid hydrodynamical simulations in two dimensions, including different dust species, which we treat as pressureless fluids. We initialize the dust outside of the planet’s orbit and study under which conditions dust grains are able to cross the gap carved by the planet. In agreement with previous work, we find that the permeability of the gap depends both on dust dynamical properties and the gas disk structure: while small dust follows the viscously accreting gas through the gap, dust grains approaching a critical size are progressively filtered out. Moreover, we introduce and compute a depletion factor that enables us to quantify the way in which higher viscosity, smaller planet mass, or a more massive disk can shift this critical size to larger values. Our results indicate that gap-opening planets may act to deplete the inner reaches of protoplanetary disks of large dust grains—potentially limiting the accretion of solids onto forming terrestrial planets.

  19. Vacuum Outer-Gap Structure in Pulsar Outer Magnetospheres

    International Nuclear Information System (INIS)

    Gui-Fang, Lin; Li, Zhang

    2009-01-01

    We study the vacuum outer-gap structure in the outer magnetosphere of rotation-powered pulsars by considering the limit of trans-field height through a pair production process. In this case, the trans-field height is limited by the photon-photon pair production process and the outer boundary of the outer gap can be extended outside the light cylinder. By solving self-consistently the Poisson equation for electrical potential and the Boltzmann equations of electrons/positrons and γ-rays in a vacuum outer gap for the parameters of Vela pulsar, we obtain an approximate geometry of the outer gap, i.e. the trans-field height is limited by the pair-production process and increases with the radial distance to the star and the width of the outer gap starts at the inner boundary (near the null charge surface) and ends at the outer boundary which locates inside or outside the light cylinder depending on the inclination angle. (geophysics, astronomy, and astrophysics)

  20. Institutional Level Identity Control Strategies in the Distance Education Environment: A Survey of Administrative Staff

    Directory of Open Access Journals (Sweden)

    Alexander Amigud

    2013-12-01

    Full Text Available Physical separation of students and instructors creates the gap of anonymity and limited control over the remote learning environment. The ability of academic institutions to authenticate students and validate authorship of academic work at various points during a course is necessary for preserving not only perceived credibility but also public safety. With the growing scope of distance education programs that permeate critical areas such as healthcare, airspace, water management, and food solutions, universities have a moral obligation to employ secure measures to verify learning outcomes. This study examines the measures universities with large distance education programs employ to align identity of learners with the academic work they do, as well as the effectiveness of and challenges and barriers to their implementation. The research was undertaken using a multiple case approach and examined survey responses from five academic administrators at five officially accredited post secondary institutions in three countries. The cases examined in the study include: Athabasca University, Open University UK, Penn State University World Campus, University of Maryland University College, and eConcordia, Concordia University’s distance learning facility. This study is not an exhaustive attempt to examine all aspects of academic integrity, but rather to create awareness about various learner authentication strategies. This study confirms that secure learner authentication in the distance education environment is possible. However, with greater pressure to enhance security of learner authentication, the openness of open learning is challenged and may change as we know it.

  1. The Effects of a 6-Week Strength Training on Critical Velocity, Anaerobic Running Distance, 30-M Sprint and Yo-Yo Intermittent Running Test Performances in Male Soccer Players.

    Science.gov (United States)

    Karsten, Bettina; Larumbe-Zabala, Eneko; Kandemir, Gokhan; Hazir, Tahir; Klose, Andreas; Naclerio, Fernando

    2016-01-01

    The objectives of this study were to examine the effects of a moderate intensity strength training on changes in critical velocity (CV), anaerobic running distance (D'), sprint performance and Yo-Yo intermittent running test (Yo-Yo IR1) performances. two recreational soccer teams were divided in a soccer training only group (SO; n = 13) and a strength and soccer training group (ST; n = 13). Both groups were tested for values of CV, D', Yo-Yo IR1 distance and 30-m sprint time on two separate occasions (pre and post intervention). The ST group performed a concurrent 6-week upper and lower body strength and soccer training, whilst the SO group performed a soccer only training. after the re-test of all variables, the ST demonstrated significant improvements for both, YoYo IR1 distance (p = 0.002) and CV values (psoccer training significantly improves CV, Yo-Yo IR1 whilst moderately improving 30-m sprint performances in non-previously resistance trained male soccer players. Critical Velocity can be recommended to coaches as an additional valid testing tool in soccer.

  2. Parametric investigation on the effect of nitrogen to reduce SF6 content in spark gap

    Science.gov (United States)

    Raj, Avinash; Khaidir, Nur; Ishak, Sanuri; Ghani, Basri Abdul; Chakrabarty, Chandan; Permal, Navitharshaani; Ahmad, Harizan

    2017-03-01

    Almost all the MV and HV switchgears used by power utilities for interrupting faults are Sulphur Hexaflouride SF6 gas circuit breakers as this gas has the best dielectric properties to quench the onset of an arc in the event of fault. However due to strong dissociating properties of this gas when in contact with air that can release fluorine into the atmosphere, the Kyoto protocol has mandated to reduce the usage of SF6 in the future. SF6 is a greenhouse gas and it's about 3000 more severe than CO2. And that's the reason for replacing this gas. A close match in the quenching properties to SF6 that is now being intensively researched is nitrogen N2. This gas is considered to be an inert gas, and its release into the atmosphere has no harmful effects (except for asphyxiation - which can be easily handled with awareness). As the need for a replacement of SF6 becomes critical in the near future, the urgency to find the right gas is immediate. Hence the proposed work in this paper is to make a comprehensive parametric investigation of N2 gas in vacuum spark-gap. The spark-gap is chosen due to flexibility in changing the gap distance and easily be housed in vacuum. The parameters to be investigated are pure N2 and N2/ SF6 mix. The settling-time of the electrical break-down voltage and current are measured using voltage probe and Pearson probe. This time is paramount as it determines the speed of breaking the circuit. A faster breaking time ensures the safety of other HV equipment in the circuit. A comparative study between the various parameters will be conducted to obtain the best recipe (gas mix and gap distance) that gives the shortest settling time the breakdown using N2/ SF6/Mixture gas was successfully conducted and a Paschen curve has been established.

  3. Pairing-gap, pseudogap, and no-gap phases in the radio-frequency spectra of a trapped unitary 6Li gas

    International Nuclear Information System (INIS)

    Pieri, P.; Perali, A.; Strinati, G. C.; Riedl, S.; Altmeyer, A.; Grimm, R.; Wright, M. J.; Kohstall, C.; Sanchez Guajardo, E. R.; Hecker Denschlag, J.

    2011-01-01

    Radio frequency spectra of a trapped unitary 6 Li gas are reported and analyzed in terms of a theoretical approach that includes both final-state and trap effects. The different strength of the final-state interaction across the trap is crucial for evidencing two main peaks associated with two distinct phases residing in different trap regions. These are the pairing-gap and pseudo-gap phases below the critical temperature T c , which evolve into the pseudo-gap and no-gap phases above T c . In this way, a long standing puzzle about the interpretation of rf spectra for 6 Li in a trap is solved.

  4. Review of wide band-gap semiconductors technology

    Directory of Open Access Journals (Sweden)

    Jin Haiwei

    2016-01-01

    Full Text Available Silicon carbide (SiC and gallium nitride (GaN are typical representative of the wide band-gap semiconductor material, which is also known as third-generation semiconductor materials. Compared with the conventional semiconductor silicon (Si or gallium arsenide (GaAs, wide band-gap semiconductor has the wide band gap, high saturated drift velocity, high critical breakdown field and other advantages; it is a highly desirable semiconductor material applied under the case of high-power, high-temperature, high-frequency, anti-radiation environment. These advantages of wide band-gap devices make them a hot spot of semiconductor technology research in various countries. This article describes the research agenda of United States and European in this area, focusing on the recent developments of the wide band-gap technology in the US and Europe, summed up the facing challenge of the wide band-gap technology.

  5. Long-Distance Rescue and Slow Extinction Dynamics Govern Multiscale Metapopulations.

    Science.gov (United States)

    Huth, Géraldine; Haegeman, Bart; Pitard, Estelle; Munoz, François

    2015-10-01

    Rare long-distance dispersal is known to be critical for species dynamics, but how the interplay between short- and long-distance colonization influences regional persistence in a fragmented habitat remains poorly understood. We propose a metapopulation model that combines local colonization within habitat islands and long-distance colonization between islands. We study how regional occupancy dynamics are affected by the multiscale colonization process. We find that the island size distribution (ISD) is a key driver of the long-term occupancy dynamics. When the ISD is heterogeneous-that is, when the size of islands is variable-we show that extinction dynamics become very slow. We demonstrate that this behavior is unrelated to the well-known extinction debt near the critical extinction threshold. Hence, this finding questions the equivalence between extinction debt and critical transitions in the context of metapopulation collapse. Furthermore, we show that long-distance colonization can rescue small islands from extinction and sustain a steady regional occupancy. These results provide novel theoretical and practical insights into extinction dynamics and persistence in fragmented habitats and are thus relevant for the design of conservation strategies.

  6. The Ontogeny of Gap Crossing Behaviour in Bornean Orangutans (Pongo pygmaeus wurmbii.

    Directory of Open Access Journals (Sweden)

    Jackie Chappell

    Full Text Available For orangutans, the largest predominantly arboreal primates, discontinuous canopy presents a particular challenge. The shortest gaps between trees lie between thin peripheral branches, which offer the least stability to large animals. The affordances of the forest canopy experienced by orangutans of different ages however, must vary substantially as adult males are an order of magnitude larger in size than infants during the early stages of locomotor independence. Orangutans have developed a diverse range of locomotor behaviour to cross gaps between trees, which vary in their physical and cognitive demands. The aims of this study were to examine the ontogeny of orangutan gap crossing behaviours and to determine which factors influence the distance orangutans crossed. A non-invasive photographic technique was used to quantify forearm length as a measure of body size. We also recorded locomotor behaviour, support use and the distance crossed between trees. Our results suggest that gap crossing varies with both physical and cognitive development. More complex locomotor behaviours, which utilized compliant trunks and lianas, were used to cross the largest gaps, but these peaked in frequency much earlier than expected, between the ages of 4 and 5 years old, which probably reflects play behaviour to perfect locomotor techniques. Smaller individuals also crossed disproportionately large gaps relative to their size, by using support deformation. Our results suggest that orangutans acquire the full repertoire of gap crossing techniques, including the more cognitively demanding ones, before weaning, but adjust the frequency of the use of these techniques to their increasing body size.

  7. The Distance between Perception and Reality in the Social Domains of Life

    OpenAIRE

    Lora, Eduardo

    2013-01-01

    The distance between perception and reality with respect to the social domains of life is often striking. Using survey data collected on Latin American countries, this paper provides an overview of the main empirical findings on the gaps between perception and reality in four social domains--health, employment, the perception of security, and social ranking. The overview emphasizes the psychological biases that may explain the gaps. Biases associated with cultural values are very relevant wit...

  8. Gaps in college biology students' understanding of photosynthesis: Implications for human constructivist learning theory and college classroom practice

    Science.gov (United States)

    Griffard, Phyllis Baudoin

    1999-11-01

    The main research question of this study was: What gaps in biochemical understanding are revealed by a range of university introductory biology students as they work through a critically acclaimed multimedia program on photosynthesis, and what are the corresponding implications for elaboration of the Ausubel-Novak-Gowin Learning Theory (ANG, now Human Constructivism)? Twelve students, mixed for ability, gender and ethnicity, were recruited from two sections of "Bio 101." Before and after instruction in photosynthesis, in-depth clinical interviews were conducted during which participants completed a range of cognitive tasks such as sorting, concept mapping, explaining and predicting. Some tasks involved interacting with a computer simulation of photosynthesis. This study primarily employed qualitative case study and verbal analysis methods. Verbal analysis of the clinical interviews revealed numerous gaps that were categorized into typologies. The two major categories were propositional gaps and processing gaps. Propositional gaps were evident in development of participants' concepts, links and constructs. Significant among these were conceptual distance gaps and continuity of matter gaps. Gaps such as convention gaps and relative significance gaps seem to be due to naivete in the discipline. Processing gaps included gaps in graphic decoding skills and relevant cognitive habits such as self-monitoring and consulting prior knowledge. Although the gaps were easier to detect and isolate with the above-average participants, all participants showed evidence of at least some of these gaps. Since some gaps are not unexpected at all but the highest literacy levels, not all the gaps identified are to be considered deficiencies. The gaps identified support the attention given by ANG theorists to the role of prior knowledge and metacognition as well as the value of graphic organizers in knowledge construction. In addition, this study revealed numerous gaps in graphic decoding

  9. Acculturative family distancing (AFD) and depression in Chinese American families.

    Science.gov (United States)

    Hwang, Wei-Chin; Wood, Jeffrey J; Fujimoto, Ken

    2010-10-01

    Knowledge of acculturative processes and their impact on immigrant families remains quite limited. Acculturative family distancing (AFD) is the distancing that occurs between immigrant parents and their children and is caused by breakdowns in communication and cultural value differences. It is a more proximal and problem-focused formulation of the acculturation gap and is hypothesized to increase depression via family conflict. Data were collected from 105 Chinese American high school students and their mothers. Rasch modeling was used to refine the AFD measure, and structural equation modeling was used to determine the effects of AFD on youth and maternal depression. Findings indicate that greater AFD was associated with higher depressive symptoms and risk for clinical depression. Family conflict partially mediated this relation for youths, whereas for mothers, AFD directly increased risk for depression. Greater mother-child heritage enculturation discrepancies were associated with greater mother and child AFD. Mainstream acculturation discrepancies and language gaps between mothers and youths were not significantly associated with any of the primary outcome variables. Results highlight the need for better understanding of how AFD and other acculturation-gap phenomena affect immigrant mental health. They also underscore the need for prevention and intervention programs that target communication difficulties and intergenerational cultural value differences. Copyright 2010 APA, all rights reserved.

  10. THE PAL 5 STAR STREAM GAPS

    International Nuclear Information System (INIS)

    Carlberg, R. G.; Hetherington, Nathan; Grillmair, C. J.

    2012-01-01

    Pal 5 is a low-mass, low-velocity-dispersion, globular cluster with spectacular tidal tails. We use the Sloan Digital Sky Survey Data Release 8 data to extend the density measurements of the trailing star stream to 23 deg distance from the cluster, at which point the stream runs off the edge of the available sky coverage. The size and the number of gaps in the stream are measured using a filter which approximates the structure of the gaps found in stream simulations. We find 5 gaps that are at least 99% confidence detections with about a dozen gaps at 90% confidence. The statistical significance of a gap is estimated using bootstrap resampling of the control regions on either side of the stream. The density minimum closest to the cluster is likely the result of the epicyclic orbits of the tidal outflow and has been discounted. To create the number of 99% confidence gaps per unit length at the mean age of the stream requires a halo population of nearly a thousand dark matter sub-halos with peak circular velocities above 1 km s –1 within 30 kpc of the galactic center. These numbers are a factor of about three below cold stream simulation at this sub-halo mass or velocity but, given the uncertainties in both measurement and more realistic warm stream modeling, are in substantial agreement with the LCDM prediction.

  11. Controllable asymmetric transmission via gap-tunable acoustic metasurface

    Science.gov (United States)

    Liu, Bingyi; Jiang, Yongyuan

    2018-04-01

    In this work, we utilize the acoustic gradient metasurface (AGM) of a bilayer configuration to realize the controllable asymmetric transmission. Relying on the adjustable gap between the two composing layers, the metasurface could switch from symmetric transmission to asymmetric transmission at a certain gap value. The underlying mechanism is attributed to the interference between the forward diffracted waves scattered by the surface bound waves at two air-AGM interfaces, which is apparently influenced by the interlayer distance. We further utilize the hybrid acoustic elements to construct the desired gradient metasurface with a tunable gap and validate the controllable asymmetric transmission with full-wave simulations. Our work provides the solution for actively controlling the transmission property of an acoustic element, which shows potential application in acoustic communication as a dynamic tunable acoustic diode.

  12. Closing the gap between the inside and the outside: interoceptive sensitivity and social distances.

    Directory of Open Access Journals (Sweden)

    Francesca Ferri

    Full Text Available Humans' ability to represent their body state from within through interoception has been proposed to predict different aspects of human cognition and behaviour. We focused on the possible contribution of interoceptive sensitivity to social behaviour as mediated by adaptive modulation of autonomic response. We, thus, investigated whether interoceptive sensitivity to one's heartbeat predicts participants' autonomic response at different social distances. We measured respiratory sinus arrhythmia (RSA during either a Social or a Non-social task. In the Social task each participant viewed an experimenter performing a caress-like movement at different distances from their hand. In the Non-social task a metal stick was moved at the same distances from the participant's hand. We found a positive association between interoceptive sensitivity and autonomic response only for the social setting. Moreover, only good heartbeat perceivers showed higher autonomic response 1 in the social compared to the non-social setting, 2 specifically, when the experimenter's hand was moving at boundary of their peripersonal space (20 cm from the participant's hand. Our findings suggest that interoceptive sensitivity might contribute to interindividual differences concerning social attitudes and interpersonal space representation via recruitment of different adaptive autonomic response strategies.

  13. Critical research gaps and translational priorities for the successful prevention and treatment of breast cancer

    Science.gov (United States)

    2013-01-01

    Introduction Breast cancer remains a significant scientific, clinical and societal challenge. This gap analysis has reviewed and critically assessed enduring issues and new challenges emerging from recent research, and proposes strategies for translating solutions into practice. Methods More than 100 internationally recognised specialist breast cancer scientists, clinicians and healthcare professionals collaborated to address nine thematic areas: genetics, epigenetics and epidemiology; molecular pathology and cell biology; hormonal influences and endocrine therapy; imaging, detection and screening; current/novel therapies and biomarkers; drug resistance; metastasis, angiogenesis, circulating tumour cells, cancer ‘stem’ cells; risk and prevention; living with and managing breast cancer and its treatment. The groups developed summary papers through an iterative process which, following further appraisal from experts and patients, were melded into this summary account. Results The 10 major gaps identified were: (1) understanding the functions and contextual interactions of genetic and epigenetic changes in normal breast development and during malignant transformation; (2) how to implement sustainable lifestyle changes (diet, exercise and weight) and chemopreventive strategies; (3) the need for tailored screening approaches including clinically actionable tests; (4) enhancing knowledge of molecular drivers behind breast cancer subtypes, progression and metastasis; (5) understanding the molecular mechanisms of tumour heterogeneity, dormancy, de novo or acquired resistance and how to target key nodes in these dynamic processes; (6) developing validated markers for chemosensitivity and radiosensitivity; (7) understanding the optimal duration, sequencing and rational combinations of treatment for improved personalised therapy; (8) validating multimodality imaging biomarkers for minimally invasive diagnosis and monitoring of responses in primary and metastatic disease

  14. Representing distance, consuming distance

    DEFF Research Database (Denmark)

    Larsen, Gunvor Riber

    Title: Representing Distance, Consuming Distance Abstract: Distance is a condition for corporeal and virtual mobilities, for desired and actual travel, but yet it has received relatively little attention as a theoretical entity in its own right. Understandings of and assumptions about distance...... are being consumed in the contemporary society, in the same way as places, media, cultures and status are being consumed (Urry 1995, Featherstone 2007). An exploration of distance and its representations through contemporary consumption theory could expose what role distance plays in forming...

  15. Gender Differences in Availability, Internet Access and Rate of Usage of Computers among Distance Education Learners.

    Science.gov (United States)

    Atan, Hanafi; Sulaiman, Fauziah; Rahman, Zuraidah Abd; Idrus, Rozhan Mohammed

    2002-01-01

    Explores the level of availability of computers, Internet accessibility, and the rate of usage of computers both at home and at the workplace between distance education learners according to gender. Results of questionnaires completed at the Universiti Sains Malaysia indicate that distance education reduces the gender gap. (Author/LRW)

  16. Understanding the Financial Knowledge Gap: A New Dimension of Inequality in Later Life.

    Science.gov (United States)

    Khan, Mohammad Nuruzzaman; Rothwell, David W; Cherney, Katrina; Sussman, Tamara

    2017-01-01

    To understand individuals' financial behaviors, it is important to understand the financial knowledge gap - the distance between one's objective and subjective financial knowledge. Overestimating one's financial knowledge can lead to risky financial behaviors. To date, limited empirical work has examined how financial knowledge gap varies across age groups. We analyze the size and nature of the financial knowledge gap and its variation across age groups. Using nationally representative data, we find robust evidence that older adults overestimate their financial knowledge. Social workers can assess the financial knowledge gap and educate their clients to protect from financial fraud, exploitation, and abuse.

  17. Gap Analysis Approach for Construction Safety Program Improvement

    Directory of Open Access Journals (Sweden)

    Thanet Aksorn

    2007-06-01

    Full Text Available To improve construction site safety, emphasis has been placed on the implementation of safety programs. In order to successfully gain from safety programs, factors that affect their improvement need to be studied. Sixteen critical success factors of safety programs were identified from safety literature, and these were validated by safety experts. This study was undertaken by surveying 70 respondents from medium- and large-scale construction projects. It explored the importance and the actual status of critical success factors (CSFs. Gap analysis was used to examine the differences between the importance of these CSFs and their actual status. This study found that the most critical problems characterized by the largest gaps were management support, appropriate supervision, sufficient resource allocation, teamwork, and effective enforcement. Raising these priority factors to satisfactory levels would lead to successful safety programs, thereby minimizing accidents.

  18. The theory of critical distances applied to problems in fracture and fatigue of bone

    Directory of Open Access Journals (Sweden)

    Emma Brazel

    2009-10-01

    Full Text Available The theory of critical distances (TCD has been applied to predict notch-based fracture and fatigue in a wide range of materials and components. The present paper describes a series of projects in which we applied this approach to human bone. Using experimental data from the literature, combined with finite element analysis, we showed that the TCD was able to predict the effect of notches and holes on the strength of bone failing in brittle fracture due to monotonic loading, in different loading regimes. Bone also displays short crack effects, leading to R-curve data for both fracture toughness and fatigue crack propagation thresholds; we showed that the TCD could predict this data. This analysis raised a number of questions for discussion, such as the significance of the L value itself in this and other materials. Finally, we applied the TCD to a practical problem in orthopaedic surgery: the management of bone defects, showing that predictions could be made which would enable surgeons to decide on whether a bone graft material would be needed to repair a defect, and to specify what mechanical properties this material should have.

  19. Tunneling Spectroscopy of the Energy Gap in MgB2 Under Magnetic Fields

    International Nuclear Information System (INIS)

    Ekino, T.; Takasaki, T.; Fujii, H.; Muranaka, T.; Akimitsu, J.

    2003-01-01

    Effects of magnetic field on the multiple-gap structure in the superconductor MgB 2 have been studied by break junctions. With increasing the field, the gap value decreases with filling up of the states inside of the gap. The gap-closing field B c correlates with the gap size. The extrapolated B c value for the larger gap is almost consistent with the upper critical field of this compound. (author)

  20. Executive summary of NIH workshop on the Use and Biology of Energy Drinks: Current Knowledge and Critical Gaps.

    Science.gov (United States)

    Sorkin, Barbara C; Camp, Kathryn M; Haggans, Carol J; Deuster, Patricia A; Haverkos, Lynne; Maruvada, Padma; Witt, Ellen; Coates, Paul M

    2014-10-01

    Sales of energy drinks in the United States reached $12.5 billion in 2012. Emergency department visits related to consumption of these products have increased sharply, and while these numbers remain small relative to product sales, they raise important questions regarding biological and behavioral effects. Although some common ingredients of energy drinks have been extensively studied (e.g., caffeine, B vitamins, sugars, inositol), data on other ingredients (e.g., taurine) are limited. Summarized here are data presented elsewhere in this issue on the prevalence and patterns of caffeine-containing energy drink use, the effects of these products on alertness, fatigue, cognitive functions, sleep, mood, homeostasis, as well as on exercise physiology and metabolism, and the biological mechanisms mediating the observed effects. There are substantial data on the effects of some energy drink ingredients, such as caffeine and sugars, on many of these outcomes; however, even for these ingredients many controversies and gaps remain, and data on other ingredients in caffeine-containing energy drinks, and on ingredient interactions, are sparse. This summary concludes with a discussion of critical gaps in the data and potential next steps. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

  1. Deuterium retention properties of co-deposited carbon films produced at wall gaps

    International Nuclear Information System (INIS)

    Nobuta, Yuji; Kanazawa, Jun; Yamauchi, Yuji; Hino, Tomoaki; Yokoyama, Kenji; Suzuki, Satoshi; Ezato, Koichiro; Enoeda, Mikio; Akiba, Masato; Akamaru, Satoshi; Hatano, Yuji

    2013-01-01

    Deuterium retention properties in co-deposited carbon film produced in gap and the relationship between this retention behavior and the crystal structure of carbon film were investigated. In the case of a wide gap, the atomic ratio of deuterium to carbon (D/C) in the film was almost constant at any depth in the gap, while in the case of a narrow gap the D/C ratio decreased with increasing distance from the gap entrance. The micro structure of carbon film tended to be more amorphous for the film produced at locations deeper in the gap. Thermal desorption spectra of D 2 in the film produced near the gap entrance showed one broad main peak at around 1100 K, while that in the film produced near the bottom showed very sharp peaks at around 950 K. This difference in desorption behavior was related with the differences of micro structure. (author)

  2. Optical properties of a two-gap buncher

    International Nuclear Information System (INIS)

    Kleeven, W.J.G.M.; Gelbart, W.; Sura, J.

    1992-01-01

    Transit time effects in a buncher become important if the transverse beam size is comparable to βλ, i.e. the distance travelled by the beam during one rf period. Particles at the edge of the beam will experience a transit time factor which is considerably larger than on axis. This is a transverse-longitudinal coupling which reduces the bunching efficiency. A semianalytical calculation is made of the properties of a two-gap buncher. Electric fields are calculated analytically. These are used to calculate transit time factors, bunching efficiency and radial deflection at the buncher gaps. Furthermore, a general formula is derived for the transverse emittance growth in a buncher due to phase mixing and due to aberrations. (orig.)

  3. Gendered Justice Gaps in Bosnia-Herzegovina

    DEFF Research Database (Denmark)

    Björkdahl, Annika; Mannergren Selimovic, Johanna

    2014-01-01

    , and reparations gaps-this article examines structural constraints for women to engage in shaping and implementing transitional justice, and unmasks transitional justice as a site for the long-term construction of the gendered post-conflict order. Thus, the gendered dynamics of peacebuilding and transitional...... justice have produced a post-conflict order characterized by gendered peace and justice gaps. Yet, we conclude that women are doing justice within the Bosnian-Herzegovina transitional justice project, and that their presence and participation is complex, multilayered, and constrained yet critical....

  4. The gap between the management and success of elite middle and ...

    African Journals Online (AJOL)

    The gap between the management and success of elite middle and long distance ... There is extensive research available on the success of Kenyan athletes, but no ... analysis was used to determine a consistent and predictable relationship ...

  5. Pediatric Critical Care Nursing Research Priorities-Initiating International Dialogue.

    Science.gov (United States)

    Tume, Lyvonne N; Coetzee, Minette; Dryden-Palmer, Karen; Hickey, Patricia A; Kinney, Sharon; Latour, Jos M; Pedreira, Mavilde L G; Sefton, Gerri R; Sorce, Lauren; Curley, Martha A Q

    2015-07-01

    To identify and prioritize research questions of concern to the practice of pediatric critical care nursing practice. One-day consensus conference. By using a conceptual framework by Benner et al describing domains of practice in critical care nursing, nine international nurse researchers presented state-of-the-art lectures. Each identified knowledge gaps in their assigned practice domain and then poised three research questions to fill that gap. Then, meeting participants prioritized the proposed research questions using an interactive multivoting process. Seventh World Congress on Pediatric Intensive and Critical Care in Istanbul, Turkey. Pediatric critical care nurses and nurse scientists attending the open consensus meeting. Systematic review, gap analysis, and interactive multivoting. The participants prioritized 27 nursing research questions in nine content domains. The top four research questions were 1) identifying nursing interventions that directly impact the child and family's experience during the withdrawal of life support, 2) evaluating the long-term psychosocial impact of a child's critical illness on family outcomes, 3) articulating core nursing competencies that prevent unstable situations from deteriorating into crises, and 4) describing the level of nursing education and experience in pediatric critical care that has a protective effect on the mortality and morbidity of critically ill children. The consensus meeting was effective in organizing pediatric critical care nursing knowledge, identifying knowledge gaps and in prioritizing nursing research initiatives that could be used to advance nursing science across world regions.

  6. Optimization of air gap for two-dimensional imaging system using synchrotron radiation

    Science.gov (United States)

    Zeniya, Tsutomu; Takeda, Tohoru; Yu, Quanwen; Hyodo, Kazuyuki; Yuasa, Tetsuya; Aiyoshi, Yuji; Hiranaka, Yukio; Itai, Yuji; Akatsuka, Takao

    2000-11-01

    Since synchrotron radiation (SR) has several excellent properties such as high brilliance, broad continuous energy spectrum and small divergence, we can obtain x-ray images with high contrast and high spatial resolution by using of SR. In 2D imaging using SR, air gap method is very effective to reduce the scatter contamination. However, to use air gap method, the geometrical effect of finite source size of SR must be considered because spatial resolution of image is degraded by air gap. For 2D x-ray imaging with SR, x-ray mammography was chosen to examine the effect of air gap method. We theoretically discussed the optimization of air gap distance suing effective scatter point source model proposed by Muntz, and executed experiment with a newly manufactured monochromator with asymmetrical reflection and an imaging plate.

  7. Empowering adolescent girls in Sub-Saharan Africa to prevent unintended pregnancy and HIV: A critical research gap.

    Science.gov (United States)

    Phillips, Sharon J; Mbizvo, Michael T

    2016-01-01

    The need to prevent early pregnancy and HIV among adolescent girls in Sub-Saharan Africa has been recognized increasingly over recent years. Although extensive work has been done to determine appropriate interventions for girls in high-income countries, very little evidence is available to guide programmatic interventions in Sub-Saharan Africa. The available evidence has been equivocal regarding improved outcomes. While knowledge and self-reported behaviors frequently change with interventions, including those performed at the community level, educational programs, and direct contraceptive provision, downstream outcomes rarely reflect a significant effect of the interventions; however, provision of financial or other interventions to incentivize continued school enrollment are a promising development. We suggest directions for future research to fill this critical gap in the literature. Copyright © 2015 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved.

  8. Quantum phase transition by employing trace distance along with the density matrix renormalization group

    International Nuclear Information System (INIS)

    Luo, Da-Wei; Xu, Jing-Bo

    2015-01-01

    We use an alternative method to investigate the quantum criticality at zero and finite temperature using trace distance along with the density matrix renormalization group. It is shown that the average correlation measured by the trace distance between the system block and environment block in a DMRG sweep is able to detect the critical points of quantum phase transitions at finite temperature. As illustrative examples, we study spin-1 XXZ chains with uniaxial single-ion-type anisotropy and the Heisenberg spin chain with staggered coupling and external magnetic field. It is found that the trace distance shows discontinuity at the critical points of quantum phase transition and can be used as an indicator of QPTs

  9. A Survey of Binary Similarity and Distance Measures

    Directory of Open Access Journals (Sweden)

    Seung-Seok Choi

    2010-02-01

    Full Text Available The binary feature vector is one of the most common representations of patterns and measuring similarity and distance measures play a critical role in many problems such as clustering, classification, etc. Ever since Jaccard proposed a similarity measure to classify ecological species in 1901, numerous binary similarity and distance measures have been proposed in various fields. Applying appropriate measures results in more accurate data analysis. Notwithstanding, few comprehensive surveys on binary measures have been conducted. Hence we collected 76 binary similarity and distance measures used over the last century and reveal their correlations through the hierarchical clustering technique.

  10. Stochastic Learning of Multi-Instance Dictionary for Earth Mover's Distance based Histogram Comparison

    OpenAIRE

    Fan, Jihong; Liang, Ru-Ze

    2016-01-01

    Dictionary plays an important role in multi-instance data representation. It maps bags of instances to histograms. Earth mover's distance (EMD) is the most effective histogram distance metric for the application of multi-instance retrieval. However, up to now, there is no existing multi-instance dictionary learning methods designed for EMD based histogram comparison. To fill this gap, we develop the first EMD-optimal dictionary learning method using stochastic optimization method. In the stoc...

  11. Probe-Substrate Distance Control in Desorption Electrospray Ionization

    Science.gov (United States)

    Yarger, Tyler J.; Yuill, Elizabeth M.; Baker, Lane A.

    2018-03-01

    We introduce probe-substrate distance (Dps)-control to desorption electrospray ionization (DESI) and report a systematic investigation of key experimental parameters. Examination of voltage, flow rate, and nebulizing gas pressure suggests as Dps decreases, the distance-dependent spray current increases, until a critical point. At the critical point the relationship inverts, and the spray current decreases as the probe moves closer to the surface due to constriction of solution flow by the nebulizing gas. Dps control was used to explore the use of spray current as a signal for feedback positioning, while mass spectrometry imaging was performed simultaneously. Further development of this technique is expected to find application in study of structure-function relationships for clinical diagnostics, biological investigation, and materials characterization. [Figure not available: see fulltext.

  12. Non-magnetic impurity effect on suppression of Tc and gap evolution in the two-gap superconductor Lu2Fe3Si5

    International Nuclear Information System (INIS)

    Nakajima, Y.; Hidaka, H.; Tamegai, T.

    2013-01-01

    Highlights: ► Non-magnetic impurities suppress T c and the amplitude of gaps in Lu 2 Fe 3 Si 5 . ► Critical scattering rate is higher than that expected in s ± -pairing scenario. ► The evolution of two distinct gaps dose not show merging the amplitude of gaps. -- Abstract: We report the suppression of T c and the evolution of amplitudes of the two gaps with the introduction of non-magnetic impurities in a two-gap superconductor Lu 2 Fe 3 Si 5 . While T c rapidly decreases by a small amount of substitution of Sc for Lu, the suppression of T c is more than ten times slower than that expected from the Abrikosov–Gor’kov equation describing the reduction of T c in a superconductor with sign reversal in the gap function. The evolution of two distinct gaps by the introduction of non-magnetic impurities does not show merging the amplitude of two gaps, which is strikingly different from the typical two-gap superconductor MgB 2

  13. Unified treatment of the luminosity distance in cosmology

    International Nuclear Information System (INIS)

    Yoo, Jaiyul; Scaccabarozzi, Fulvio

    2016-01-01

    Comparing the luminosity distance measurements to its theoretical predictions is one of the cornerstones in establishing the modern cosmology. However, as shown in Biern and Yoo, its theoretical predictions in literature are often plagued with infrared divergences and gauge-dependences. This trend calls into question the sanity of the methods used to derive the luminosity distance. Here we critically investigate four different methods—the geometric approach, the Sachs approach, the Jacobi mapping approach, and the geodesic light cone (GLC) approach to modeling the luminosity distance, and we present a unified treatment of such methods, facilitating the comparison among the methods and checking their sanity. All of these four methods, if exercised properly, can be used to reproduce the correct description of the luminosity distance.

  14. Unified treatment of the luminosity distance in cosmology

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Jaiyul; Scaccabarozzi, Fulvio, E-mail: jyoo@physik.uzh.ch, E-mail: fulvio@physik.uzh.ch [Center for Theoretical Astrophysics and Cosmology, Institute for Computational Science, University of Zürich, Zürich (Switzerland)

    2016-09-01

    Comparing the luminosity distance measurements to its theoretical predictions is one of the cornerstones in establishing the modern cosmology. However, as shown in Biern and Yoo, its theoretical predictions in literature are often plagued with infrared divergences and gauge-dependences. This trend calls into question the sanity of the methods used to derive the luminosity distance. Here we critically investigate four different methods—the geometric approach, the Sachs approach, the Jacobi mapping approach, and the geodesic light cone (GLC) approach to modeling the luminosity distance, and we present a unified treatment of such methods, facilitating the comparison among the methods and checking their sanity. All of these four methods, if exercised properly, can be used to reproduce the correct description of the luminosity distance.

  15. DISTANCES TO DARK CLOUDS: COMPARING EXTINCTION DISTANCES TO MASER PARALLAX DISTANCES

    International Nuclear Information System (INIS)

    Foster, Jonathan B.; Jackson, James M.; Stead, Joseph J.; Hoare, Melvin G.; Benjamin, Robert A.

    2012-01-01

    We test two different methods of using near-infrared extinction to estimate distances to dark clouds in the first quadrant of the Galaxy using large near-infrared (Two Micron All Sky Survey and UKIRT Infrared Deep Sky Survey) surveys. Very long baseline interferometry parallax measurements of masers around massive young stars provide the most direct and bias-free measurement of the distance to these dark clouds. We compare the extinction distance estimates to these maser parallax distances. We also compare these distances to kinematic distances, including recent re-calibrations of the Galactic rotation curve. The extinction distance methods agree with the maser parallax distances (within the errors) between 66% and 100% of the time (depending on method and input survey) and between 85% and 100% of the time outside of the crowded Galactic center. Although the sample size is small, extinction distance methods reproduce maser parallax distances better than kinematic distances; furthermore, extinction distance methods do not suffer from the kinematic distance ambiguity. This validation gives us confidence that these extinction methods may be extended to additional dark clouds where maser parallaxes are not available.

  16. A Model for Scaffolding Traditional Distance Learners in Africa for ...

    African Journals Online (AJOL)

    How can we solve the lull in uptake and usage of online learning amongst traditional distance learners in Africa? Several online learning initiatives are taking place in Africa, but a critical assessment of their impact in terms of increasing access to higher education through distance learning indicates, in most cases, lack of ...

  17. Connecting in distance mentoring: communication practices that work.

    Science.gov (United States)

    Lasater, Kathie; Young, Patricia K; Mitchell, Claudia G; Delahoyde, Theresa M; Nick, Jan M; Siktberg, Linda

    2014-04-01

    As nursing and healthcare become more global, supported by technology, the opportunities for distance mentoring increase. Mentorship is critical to nurse educator recruitment and retention. The purpose of this study was to identify communication practices of nurse educators involved in mentoring at a distance. A qualitative design, utilizing in-person or telephone interviews was used. Participants were twenty-three protégés or mentors who were part of a yearlong distance mentoring program. An iterative process of hermeneutic analysis identified three themes; this paper focuses on the theme of connectedness. Participant narratives illuminate practices of connecting at a distance: meeting face-to-face, sharing personal information, experiencing reciprocity, journaling, being vulnerable, establishing one's presence, and appreciating different perspectives. Distance does not appear to limit the connecting potential leading to a meaningful mentoring relationship; rather, it offers possibilities that local mentoring relationships may not. Nurse educators in under-resourced countries, those in small programs without a cadre of senior faculty, and students in distance programs are among those who stand to benefit from distance mentoring relationships. © 2013.

  18. Capacity Prediction Model Based on Limited Priority Gap-Acceptance Theory at Multilane Roundabouts

    Directory of Open Access Journals (Sweden)

    Zhaowei Qu

    2014-01-01

    Full Text Available Capacity is an important design parameter for roundabouts, and it is the premise of computing their delay and queue. Roundabout capacity has been studied for decades, and empirical regression model and gap-acceptance model are the two main methods to predict it. Based on gap-acceptance theory, by considering the effect of limited priority, especially the relationship between limited priority factor and critical gap, a modified model was built to predict the roundabout capacity. We then compare the results between Raff’s method and maximum likelihood estimation (MLE method, and the MLE method was used to predict the critical gaps. Finally, the predicted capacities from different models were compared, with the observed capacity by field surveys, which verifies the performance of the proposed model.

  19. New method for distance-based close following safety indicator.

    Science.gov (United States)

    Sharizli, A A; Rahizar, R; Karim, M R; Saifizul, A A

    2015-01-01

    The increase in the number of fatalities caused by road accidents involving heavy vehicles every year has raised the level of concern and awareness on road safety in developing countries like Malaysia. Changes in the vehicle dynamic characteristics such as gross vehicle weight, travel speed, and vehicle classification will affect a heavy vehicle's braking performance and its ability to stop safely in emergency situations. As such, the aim of this study is to establish a more realistic new distance-based safety indicator called the minimum safe distance gap (MSDG), which incorporates vehicle classification (VC), speed, and gross vehicle weight (GVW). Commercial multibody dynamics simulation software was used to generate braking distance data for various heavy vehicle classes under various loads and speeds. By applying nonlinear regression analysis to the simulation results, a mathematical expression of MSDG has been established. The results show that MSDG is dynamically changed according to GVW, VC, and speed. It is envisaged that this new distance-based safety indicator would provide a more realistic depiction of the real traffic situation for safety analysis.

  20. A tiger beetle’s pursuit of prey depends on distance

    Science.gov (United States)

    Noest, R. M.; Wang, Z. Jane

    2017-04-01

    Tiger beetles pursue prey by adjusting their heading according to a time-delayed proportional control law that minimizes the error angle (Haselsteiner et al 2014 J. R. Soc. Interface 11 20140216). This control law can be further interpreted in terms of mechanical actuation: to catch prey, tiger beetles exert a sideways force by biasing their tripod gait in proportion to the error angle measured half a stride earlier. The proportional gain was found to be nearly optimal in the sense that it minimizes the time to point directly toward the prey. For a time-delayed linear proportional controller, the optimal gain, k, is inversely proportional to the time delay, τ, and satisfies kτ =1/e . Here we present evidence that tiger beetles adjust their control gain during their pursuit of prey. Our analysis shows two critical distances: one corresponding to the beetle’s final approach to the prey, and the second, less expected, occurring at a distance around 10 cm for a prey size of 4.5 mm. The beetle initiates its chase using a sub-critical gain and increases the gain to the optimal value once the prey is within this critical distance. Insects use a variety of methods to detect distance, often involving different visual cues. Here we examine two such methods: one based on motion parallax and the other based on the prey’s elevation angle. We show that, in order for the motion parallax method to explain the observed data, the beetle needs to correct for the ratio of the prey’s sideways velocity relative to its own. On the other hand, the simpler method based on the elevation angle can detect both the distance and the prey’s size. Moreover we find that the transition distance corresponds to the accuracy required to distinguish small prey from large predators.

  1. GapMap: Enabling Comprehensive Autism Resource Epidemiology.

    Science.gov (United States)

    Albert, Nikhila; Daniels, Jena; Schwartz, Jessey; Du, Michael; Wall, Dennis P

    2017-05-04

    For individuals with autism spectrum disorder (ASD), finding resources can be a lengthy and difficult process. The difficulty in obtaining global, fine-grained autism epidemiological data hinders researchers from quickly and efficiently studying large-scale correlations among ASD, environmental factors, and geographical and cultural factors. The objective of this study was to define resource load and resource availability for families affected by autism and subsequently create a platform to enable a more accurate representation of prevalence rates and resource epidemiology. We created a mobile application, GapMap, to collect locational, diagnostic, and resource use information from individuals with autism to compute accurate prevalence rates and better understand autism resource epidemiology. GapMap is hosted on AWS S3, running on a React and Redux front-end framework. The backend framework is comprised of an AWS API Gateway and Lambda Function setup, with secure and scalable end points for retrieving prevalence and resource data, and for submitting participant data. Measures of autism resource scarcity, including resource load, resource availability, and resource gaps were defined and preliminarily computed using simulated or scraped data. The average distance from an individual in the United States to the nearest diagnostic center is approximately 182 km (50 miles), with a standard deviation of 235 km (146 miles). The average distance from an individual with ASD to the nearest diagnostic center, however, is only 32 km (20 miles), suggesting that individuals who live closer to diagnostic services are more likely to be diagnosed. This study confirmed that individuals closer to diagnostic services are more likely to be diagnosed and proposes GapMap, a means to measure and enable the alleviation of increasingly overburdened diagnostic centers and resource-poor areas where parents are unable to diagnose their children as quickly and easily as needed. GapMap will

  2. Safety distance for preventing hot particle ignition of building insulation materials

    Directory of Open Access Journals (Sweden)

    Jiayun Song

    2014-01-01

    Full Text Available Trajectories of flying hot particles were predicted in this work, and the temperatures during the movement were also calculated. Once the particle temperature decreased to the critical temperature for a hot particle to ignite building insulation materials, which was predicted by hot-spot ignition theory, the distance particle traveled was determined as the minimum safety distance for preventing the ignition of building insulation materials by hot particles. The results showed that for sphere aluminum particles with the same initial velocities and diameters, the horizontal and vertical distances traveled by particles with higher initial temperatures were higher. Smaller particles traveled farther when other conditions were the same. The critical temperature for an aluminum particle to ignite rigid polyurethane foam increased rapidly with the decrease of particle diameter. The horizontal and vertical safety distances were closely related to the initial temperature, diameter and initial velocity of particles. These results could help update the safety provision of firework display.

  3. Ministerial formation of theological students through distance education

    Directory of Open Access Journals (Sweden)

    Marilyn Naidoo

    2012-02-01

    Full Text Available Ministerial formation is a multifaceted activity involving critical thinking, the acquisition of knowledge, skills development, religious identity formation and the development of ministerial and spiritual maturity expected of church ministers. Education is not merely the accumulation of a prescribed set of academic credits but includes the holistic formation of all aspects of the individual. However, theological educators are concerned about the capacity to foster such values and skills in the distance and electronic environment. Some see distance education as ‘distancing’ the students in more significant ways than simply geographic distance. These issues are of fundamental importance for they reflect the deeper convictions of theologians that distance education may not be a suitable medium for ministerial formation. This article creates a conceptual map of the theological and pedagogical challenges for ministerial formation and highlights how the possibility of formation is being carried out in the distance-learning environment.

  4. The Effect of Gap Angle on Tensile Strength of Preceramic Base Metal Solder Joints.

    Science.gov (United States)

    Fattahi, Farnaz; Hashemi Ardakani, Zahra; Hashemi Ardakani, Maryam

    2015-12-01

    Soldering is a process commonly used in fabricating dental prosthesis. Since most soldered prosthesis fail at the solder joints; the joint strength is of utmost importance. The purpose of this study was to evaluate the effect of gap angle on the tensile strength of base metal solder joints. A total number of 40 Ni-Cr samples were fabricated according to ADA/ISO 9693 specifications for tensile test. Samples were cut at the midpoint of the bar, and were placed at the considered angles by employing an explicitly designed device. They were divided into 4 groups regarding the gap angle; Group C (control group) with parallel gap on steady distance of 0.2mm, Group 1: 10°, Group 2: 20°, and Group3: 30° gap angles. When soldered, the specimens were all tested for tensile strength using a universal testing machine at a cross-head speed of 0.5 mm/min with a preload of 10N. Kruskal-Wallis H test was used to compare tensile strength among the groups (ptensile strength values obtained from the study groups were respectively 307.84, 391.50, 365.18, and 368.86 MPa. The tensile strength was not statistically different among the four groups in general (p≤ 0.490). Making the gap angular at the solder joints and the subsequent unsteady increase of the gap distance would not change the tensile strength of the joint.

  5. Potential and Actual Health Hazards in the Dense Urban Operational Environment: Critical Gaps and Solutions for Military Occupational Health.

    Science.gov (United States)

    Patterson, Steven L; Dancy, Blair C R; Ippolito, Danielle L; Stallings, Jonathan D

    2017-11-01

    : This paper presents environmental health risks which are prevalent in dense urban environments.We review the current literature and recommendations proposed by environmental medicine experts in a 2-day symposium sponsored by the Department of Defense and supported by the Johns Hopkins University Applied Physics Laboratory.Key hazards in the dense urban operational environment include toxic industrial chemicals and materials, water pollution and sewage, and air pollution. Four critical gaps in environmental medicine were identified: prioritizing chemical and environmental concerns, developing mobile decision aids, personalized health assessments, and better real-time health biomonitoring.As populations continue to concentrate in cities, civilian and military leaders will need to meet emerging environmental health concerns by developing and delivering adequate technology and policy solutions.

  6. Magnetization states and switching in narrow-gapped ferromagnetic nanorings

    Directory of Open Access Journals (Sweden)

    Jie Li

    2012-03-01

    Full Text Available We study permalloy nanorings that are lithographically fabricated with narrow gaps that break the rotational symmetry of the ring while retaining the vortex ground state, using both micromagnetic simulations and magnetic force microscopy (MFM. The vortex chirality in these structures can be readily set with an in-plane magnetic field and easily probed by MFM due to the field associated with the gap, suggesting such rings for possible applications in storage technologies. We find that the gapped ring edge characteristics (i.e., edge profile and gap shape are critical in determining the magnetization switching field, thus elucidating an essential parameter in the controls of devices that might incorporate such structures.

  7. Understanding the carbon dioxide gaps.

    Science.gov (United States)

    Scheeren, Thomas W L; Wicke, Jannis N; Teboul, Jean-Louis

    2018-06-01

    The current review attempts to demonstrate the value of several forms of carbon dioxide (CO2) gaps in resuscitation of the critically ill patient as monitor for the adequacy of the circulation, as target for fluid resuscitation and also as predictor for outcome. Fluid resuscitation is one of the key treatments in many intensive care patients. It remains a challenge in daily practice as both a shortage and an overload in intravascular volume are potentially harmful. Many different approaches have been developed for use as target of fluid resuscitation. CO2 gaps can be used as surrogate for the adequacy of cardiac output (CO) and as marker for tissue perfusion and are therefore a potential target for resuscitation. CO2 gaps are easily measured via point-of-care analysers. We shed light on its potential use as nowadays it is not widely used in clinical practice despite its potential. Many studies were conducted on partial CO2 pressure differences or CO2 content (cCO2) differences either alone, or in combination with other markers for outcome or resuscitation adequacy. Furthermore, some studies deal with CO2 gap to O2 gap ratios as target for goal-directed fluid therapy or as marker for outcome. CO2 gap is a sensitive marker of tissue hypoperfusion, with added value over traditional markers of tissue hypoxia in situations in which an oxygen diffusion barrier exists such as in tissue oedema and impaired microcirculation. Venous-to-arterial cCO2 or partial pressure gaps can be used to evaluate whether attempts to increase CO should be made. Considering the potential of the several forms of CO2 measurements and its ease of use via point-of-care analysers, it is recommendable to implement CO2 gaps in standard clinical practice.

  8. Quantum-critical scaling of fidelity in 2D pairing models

    Energy Technology Data Exchange (ETDEWEB)

    Adamski, Mariusz, E-mail: mariusz.adamski@ift.uni.wroc.pl [Institute of Theoretical Physics, University of Wrocław, pl. Maksa Borna 9, 50–204, Wrocław (Poland); Jȩdrzejewski, Janusz [Institute of Theoretical Physics, University of Wrocław, pl. Maksa Borna 9, 50–204, Wrocław (Poland); Krokhmalskii, Taras [Institute for Condensed Matter Physics, 1 Svientsitski Street, 79011, Lviv (Ukraine)

    2017-01-15

    The laws of quantum-critical scaling theory of quantum fidelity, dependent on the underlying system dimensionality D, have so far been verified in exactly solvable 1D models, belonging to or equivalent to interacting, quadratic (quasifree), spinless or spinfull, lattice-fermion models. The obtained results are so appealing that in quest for correlation lengths and associated universal critical indices ν, which characterize the divergence of correlation lengths on approaching critical points, one might be inclined to substitute the hard task of determining an asymptotic behavior at large distances of a two-point correlation function by an easier one, of determining the quantum-critical scaling of the quantum fidelity. However, the role of system's dimensionality has been left as an open problem. Our aim in this paper is to fill up this gap, at least partially, by verifying the laws of quantum-critical scaling theory of quantum fidelity in a 2D case. To this end, we study correlation functions and quantum fidelity of 2D exactly solvable models, which are interacting, quasifree, spinfull, lattice-fermion models. The considered 2D models exhibit new, as compared with 1D ones, features: at a given quantum-critical point there exists a multitude of correlation lengths and multiple universal critical indices ν, since these quantities depend on spatial directions, moreover, the indices ν may assume larger values. These facts follow from the obtained by us analytical asymptotic formulae for two-point correlation functions. In such new circumstances we discuss the behavior of quantum fidelity from the perspective of quantum-critical scaling theory. In particular, we are interested in finding out to what extent the quantum fidelity approach may be an alternative to the correlation-function approach in studies of quantum-critical points beyond 1D.

  9. The critic as transvestite: the parody nature of literary criticism

    Directory of Open Access Journals (Sweden)

    David Pruneda Sentíes

    2016-09-01

    Full Text Available This paper explores a path in the analysis of literary criticism as an object of study. In order to convey this, this essay attempts to define literary criticism as a genre that parodies the literary text it aspires to examine. Mikhail Bakhtin’s analysis of the novelistic discourse is useful to establish a connection between parody and criticism. Although Bakhtin discusses the novel, I ascertain that his arguments may be applied to the description of criticism as a parodic-travestying genre. Secondly, this paper discusses Linda Hutcheon’s work, which states that parody is a repetition of the original text. According to Hutcheon, this repetition implies a critical distance with the parodied text, which marks difference rather than similarity.

  10. Bridging the Research-Practice Gap: Research Translation and/or Research Transformation

    Science.gov (United States)

    Hirschkorn, Mark; Geelan, David

    2008-01-01

    The issue of the "research-practice gap"--the problematic relationship between research in education and educational practice--has been widely reported in the literature. This critical literature review explores some of the causes and features of the gap and suggests some possible approaches for addressing it. These solutions involve changes in…

  11. Superconductivity versus quantum criticality: Effects of thermal fluctuations

    Science.gov (United States)

    Wang, Huajia; Wang, Yuxuan; Torroba, Gonzalo

    2018-02-01

    We study the interplay between superconductivity and non-Fermi liquid behavior of a Fermi surface coupled to a massless SU(N ) matrix boson near the quantum critical point. The presence of thermal infrared singularities in both the fermionic self-energy and the gap equation invalidates the Eliashberg approximation, and makes the quantum-critical pairing problem qualitatively different from that at zero temperature. Taking the large N limit, we solve the gap equation beyond the Eliashberg approximation, and obtain the superconducting temperature Tc as a function of N . Our results show an anomalous scaling between the zero-temperature gap and Tc. For N greater than a critical value, we find that Tc vanishes with a Berezinskii-Kosterlitz-Thouless scaling behavior, and the system retains non-Fermi liquid behavior down to zero temperature. This confirms and extends previous renormalization-group analyses done at T =0 , and provides a controlled example of a naked quantum critical point. We discuss the crucial role of thermal fluctuations in relating our results with earlier work where superconductivity always develops due to the special role of the first Matsubara frequency.

  12. Direct optical band gap measurement in polycrystalline semiconductors: A critical look at the Tauc method

    International Nuclear Information System (INIS)

    Dolgonos, Alex; Mason, Thomas O.; Poeppelmeier, Kenneth R.

    2016-01-01

    The direct optical band gap of semiconductors is traditionally measured by extrapolating the linear region of the square of the absorption curve to the x-axis, and a variation of this method, developed by Tauc, has also been widely used. The application of the Tauc method to crystalline materials is rooted in misconception–and traditional linear extrapolation methods are inappropriate for use on degenerate semiconductors, where the occupation of conduction band energy states cannot be ignored. A new method is proposed for extracting a direct optical band gap from absorption spectra of degenerately-doped bulk semiconductors. This method was applied to pseudo-absorption spectra of Sn-doped In 2 O 3 (ITO)—converted from diffuse-reflectance measurements on bulk specimens. The results of this analysis were corroborated by room-temperature photoluminescence excitation measurements, which yielded values of optical band gap and Burstein–Moss shift that are consistent with previous studies on In 2 O 3 single crystals and thin films. - Highlights: • The Tauc method of band gap measurement is re-evaluated for crystalline materials. • Graphical method proposed for extracting optical band gaps from absorption spectra. • The proposed method incorporates an energy broadening term for energy transitions. • Values for ITO were self-consistent between two different measurement methods.

  13. Long-Term Regeneration and Functional Recovery of a 15 mm Critical Nerve Gap Bridged by Tremella fuciformis Polysaccharide-Immobilized Polylactide Conduits

    Directory of Open Access Journals (Sweden)

    Shan-hui Hsu

    2013-01-01

    Full Text Available Novel peripheral nerve conduits containing the negatively charged Tremella fuciformis polysaccharide (TF were prepared, and their efficacy in bridging a critical nerve gap was evaluated. The conduits were made of poly(D,L-lactide (PLA with asymmetric microporous structure. TF was immobilized on the lumen surface of the nerve conduits after open air plasma activation. The TF-modified surface was characterized by the attenuated total reflection Fourier-transformed infrared spectroscopy and the scanning electron microscopy. TF modification was found to enhance the neurotrophic gene expression of C6 glioma cells in vitro. TF-modified PLA nerve conduits were tested for their ability to bridge a 15 mm gap of rat sciatic nerve. Nerve regeneration was monitored by the magnetic resonance imaging. Results showed that TF immobilization promoted the nerve connection in 6 weeks. The functional recovery in animals receiving TF-immobilized conduits was greater than in those receiving the bare conduits during an 8-month period. The degree of functional recovery reached ~90% after 8 months in the group of TF-immobilized conduits.

  14. Kinetic calculation of plasma deposition in castellated tile gaps

    International Nuclear Information System (INIS)

    Dejarnac, R.; Gunn, J.P.

    2007-01-01

    Plasma-facing divertors and limiters are armoured with castellated tiles to withstand intense heat fluxes. Recent experimental studies show that a non-negligible amount of deuterium is deposited in the gaps between tiles. We present here a numerical study of plasma deposition in this critical region. For this purpose we have developed a particle-in-cell code with realistic boundary conditions determined from kinetic calculations. We find a strong asymmetry of plasma deposition into the gaps. A significant fraction of the plasma influx is expelled from the gap to be deposited on the leading edge of the downstream tile

  15. Weighted Distances in Scale-Free Configuration Models

    Science.gov (United States)

    Adriaans, Erwin; Komjáthy, Júlia

    2018-01-01

    In this paper we study first-passage percolation in the configuration model with empirical degree distribution that follows a power-law with exponent τ \\in (2,3) . We assign independent and identically distributed (i.i.d.) weights to the edges of the graph. We investigate the weighted distance (the length of the shortest weighted path) between two uniformly chosen vertices, called typical distances. When the underlying age-dependent branching process approximating the local neighborhoods of vertices is found to produce infinitely many individuals in finite time—called explosive branching process—Baroni, Hofstad and the second author showed in Baroni et al. (J Appl Probab 54(1):146-164, 2017) that typical distances converge in distribution to a bounded random variable. The order of magnitude of typical distances remained open for the τ \\in (2,3) case when the underlying branching process is not explosive. We close this gap by determining the first order of magnitude of typical distances in this regime for arbitrary, not necessary continuous edge-weight distributions that produce a non-explosive age-dependent branching process with infinite mean power-law offspring distributions. This sequence tends to infinity with the amount of vertices, and, by choosing an appropriate weight distribution, can be tuned to be any growing function that is O(log log n) , where n is the number of vertices in the graph. We show that the result remains valid for the the erased configuration model as well, where we delete loops and any second and further edges between two vertices.

  16. Experiments on graphite block gaps connected with leak flow in bottom-core structure of experimental very high-temperature gas-cooled reactor

    International Nuclear Information System (INIS)

    Kikuchi, Kenji; Futakawa, Masatoshi; Takizuka, Takakazu; Kaburaki, Hideo; Sanokawa, Konomo

    1984-01-01

    In order to minimize the leak flow rate of an experimental VHTR (a multi-purpose very high-temperature gas-cooled reactor), the graphite blocks are tightened to reduce the gap distance between blocks by core restrainers surrounded outside of the fixed reflectors of the bottom-core structure and seal elements are placed in the gaps. By using a 1/2.75-scale model of the bottom-core structure, the experiments on the following items have been carried out: a relationship between core restraint force and block gap, a relationship between core restraint force and inclined angle of the model, leak flow characteristics of seal elements etc. The conclusions derived from the experiments are as follows: (1) Core restraint force is significantly effective for decreasing the gap distance between hot plenum blocks, but ineffective for the gap between hot plenum block and fixed reflector. (2) Graphite seal element reduces the leak flow rate from the top surface of hot plenum block into plenum region to one-third. (author)

  17. Development of heat transfer models for gap cooling

    Energy Technology Data Exchange (ETDEWEB)

    Kohriyama, Tamio; Murase, Michio; Tamaki, Tomohiko [Institute of Nuclear Safety System Inc., Mihama, Fukui (Japan)

    2001-09-01

    In a severe accident of a light water reactor (LWR), heat transfer models in a narrow annular gap between superheated core debris and a reactor pressure vessel (RPV) are important to evaluate the integrity of RPV and emergency procedures. This paper discusses the effects of superheat on the heat flux based on existing data. In low superheat conditions, the heat flux in the narrow gap is higher than the heat flux in pool nucleate boiling due to restricted flow area. It approaches the nucleate boiling heat flux as superheat increasing and reaches a critical value subject to the counter-current flow limiting (CCFL) at the top end of the gap. A heat transfer correlation was derived as a function of dimensionless superheat and a Kutateladze-type CCFL correlation was deduced for critical heat flux (CHF) restricted by CCFL, which gave good prediction for a wide range of the CHF data. Effect of an angle of inclination of the gap could also be incorporated in the CCFL correlation. In high superheat conditions, the heat flux in the narrow gap maintains a similar shape to the pool boiling curve but shifts the position to a higher superheated side than the pool boiling except film boiling, which could be expressed by the typical pool film boiling correlation. Incorporating quench test data, the heat flux correlation was derived as a function of dimensionless superheat using the same formula for the low superheat and the Kutateladze-type CCFL correlation was deduced for CHF. The CHF at the high superheat was 3-4 times as large as CHF at the low superheat and this difference was well predicted by different flow patterns in the gap and the balance of pressure gradients between gas and liquid phases. (author)

  18. Determination of critical breakage conditions for double glazing in fire

    International Nuclear Information System (INIS)

    Wang, Yu; Li, Ke; Su, Yanfei; Lu, Wei; Wang, Qingsong; Sun, Jinhua; He, Linghui; Liew, K.M.

    2017-01-01

    Highlights: • Critical heat fluxes of exposed and ambient panes are 6 kW/m"2 and 25 kW/m"2. • Critical temperature difference of fire side pane is around 60 °C. • The ambient pane survives three times longer due to radiation filter and air gap. • Heat transfer in double glazing is revealed by a heat flux based theoretical model. - Abstract: Double glazing unit normally demonstrates better fire resistance than single glazing, but the knowledge on its thermal behavior and heat transfer mechanism during fire is limited. In this work, nine double glazing units were heated by a 500 × 500 mm"2 pool fire. The incident heat flux, temperature on four surfaces, breakage time and cracking behavior were obtained. The critical breakage conditions for interior and exterior panes were determined through gradually decreasing the glass-burner distance from 750 mm to 450 mm. It is established that in double glazing the pane at ambient side can withstand significantly more time than the pane exposed to fire. The critical temperature difference for interior pane is 60 °C; the critical temperature of exterior pane breakage is much higher due to no frame-covered area. In addition, the heat flux at the time of crack initiation is 6 kW/m"2 for the pane at fire side, while more than 25 kW/m"2 for ambient side pane. To reveal the heat transfer mechanism in glazing-air-glazing, theoretical and numerical investigations are also performed, which agrees well with the experimental results.

  19. Superconducting energy gap of YB6 studied by point-contact spectroscopy

    International Nuclear Information System (INIS)

    Szabo, Pavol; Kacmarcik, Jozef; Samuely, Peter; Girovsky, Jan; Gabani, Slavomir; Flachbart, Karol; Mori, Takao

    2007-01-01

    Yttrium hexaboride has the second highest critical temperature, T c ∼ 8 K, among all borides. The presented paper deals with the experimental study of its superconducting energy gap established by the method of the point-contact spectroscopy. The temperature dependence of the energy gap and the strength of the superconducting coupling is presented

  20. LHC Abort Gap Filling by Proton Beam

    CERN Document Server

    Fartoukh, Stéphane David; Shaposhnikova, Elena

    2004-01-01

    Safe operation of the LHC beam dump relies on the possibility of firing the abort kicker at any moment during beam operation. One of the necessary conditions for this is that the number of particles in the abort gap should be below some critical level defined by quench limits. Various scenarios can lead to particles filling the abort gap. Time scales associated with these scenarios are estimated for injection energy and also coast where synchrotron radiation losses are not negligible for uncaptured particle motion. Two cases are considered, with RF on and RF off. The equilibrium distribution of lost particles in the abort gap defines the requirements for maximum tolerable relative loss rate and as a consequence the minimum acceptable longitudinal lifetime of the proton beam in collision.

  1. Distance Students and Online Research: Promoting Information Literacy through Media Literacy

    Science.gov (United States)

    Van de Vord, Rebecca

    2010-01-01

    Today's college students, particularly distance students, are increasingly dependent on the Web for their research needs. At the same time they lack the critical thinking skills required to successfully evaluate the actual credibility of online information, a critical aspect of information literacy. Furthermore, rather than access the online…

  2. A Critical Theory Perspective on Accelerated Learning.

    Science.gov (United States)

    Brookfield, Stephen D.

    2003-01-01

    Critically analyzes accelerated learning using concepts from Herbert Marcuse (rebellious subjectivity) and Erich Fromm (automaton conformity). Concludes that, by providing distance and separation, accelerated learning has more potential to stimulate critical autonomous thought. (SK)

  3. Mind the Gap

    Science.gov (United States)

    2008-09-01

    Astronomers have been able to study planet-forming discs around young Sun-like stars in unsurpassed detail, clearly revealing the motion and distribution of the gas in the inner parts of the disc. This result, which possibly implies the presence of giant planets, was made possible by the combination of a very clever method enabled by ESO's Very Large Telescope. Uncovering the disc ESO PR Photo 27a/08 Planet-forming Disc Planets could be home to other forms of life, so the study of exoplanets ranks very high in contemporary astronomy. More than 300 planets are already known to orbit stars other than the Sun, and these new worlds show an amazing diversity in their characteristics. But astronomers don't just look at systems where planets have already formed - they can also get great insights by studying the discs around young stars where planets may currently be forming. "This is like going 4.6 billion years back in time to watch how the planets of our own Solar System formed," says Klaus Pontoppidan from Caltech, who led the research. Pontoppidan and colleagues have analysed three young analogues of our Sun that are each surrounded by a disc of gas and dust from which planets could form. These three discs are just a few million years old and were known to have gaps or holes in them, indicating regions where the dust has been cleared and the possible presence of young planets. The new results not only confirm that gas is present in the gaps in the dust, but also enable astronomers to measure how the gas is distributed in the disc and how the disc is oriented. In regions where the dust appears to have been cleared out, molecular gas is still highly abundant. This can either mean that the dust has clumped together to form planetary embryos, or that a planet has already formed and is in the process of clearing the gas in the disc. For one of the stars, SR 21, a likely explanation is the presence of a massive giant planet orbiting at less than 3.5 times the distance

  4. Critical role of gap junction communication, calcium and nitric oxide signaling in bystander responses to focal photodynamic injury.

    Science.gov (United States)

    Calì, Bianca; Ceolin, Stefano; Ceriani, Federico; Bortolozzi, Mario; Agnellini, Andrielly H R; Zorzi, Veronica; Predonzani, Andrea; Bronte, Vincenzo; Molon, Barbara; Mammano, Fabio

    2015-04-30

    Ionizing and nonionizing radiation affect not only directly targeted cells but also surrounding "bystander" cells. The underlying mechanisms and therapeutic role of bystander responses remain incompletely defined. Here we show that photosentizer activation in a single cell triggers apoptosis in bystander cancer cells, which are electrically coupled by gap junction channels and support the propagation of a Ca2+ wave initiated in the irradiated cell. The latter also acts as source of nitric oxide (NO) that diffuses to bystander cells, in which NO levels are further increased by a mechanism compatible with Ca(2+)-dependent enzymatic production. We detected similar signals in tumors grown in dorsal skinfold chambers applied to live mice. Pharmacological blockade of connexin channels significantly reduced the extent of apoptosis in bystander cells, consistent with a critical role played by intercellular communication, Ca2+ and NO in the bystander effects triggered by photodynamic therapy.

  5. Male and female contributions to behavioral isolation in darters as a function of genetic distance and color distance

    Science.gov (United States)

    Moran, Rachel L.; Zhou, Muchu; Catchen, Julian M.; Fuller, Rebecca C.

    2017-01-01

    Abstract Determining which reproductive isolating barriers arise first between geographically isolated lineages is critical to understanding allopatric speciation. We examined behavioral isolation among four recently diverged allopatric species in the orangethroat darter clade (Etheostoma: Ceasia). We also examined behavioral isolation between each Ceasia species and the sympatric rainbow darter Etheostoma caeruleum. We asked (1) is behavioral isolation present between allopatric Ceasia species, and how does this compare to behavioral isolation with E. caeruleum, (2) does male color distance and/or genetic distance predict behavioral isolation between species, and (3) what are the relative contributions of female choice, male choice, and male competition to behavioral isolation? We found that behavioral isolation, genetic differentiation, and male color pattern differentiation were present between allopatric Ceasia species. Males, but not females, discerned between conspecific and heterospecific mates. Males also directed more aggression toward conspecific rival males. The high levels of behavioral isolation among Ceasia species showed no obvious pattern with genetic distance or male color distance. However, when the E. caeruleum was included in the analysis, an association between male aggression and male color distance was apparent. We discuss the possibility that reinforcement between Ceasia and E. caeruleum is driving behavioral isolation among allopatric Ceasia species. PMID:28776645

  6. Gap junctions and epileptic seizures--two sides of the same coin?

    Directory of Open Access Journals (Sweden)

    Vladislav Volman

    Full Text Available Electrical synapses (gap junctions play a pivotal role in the synchronization of neuronal ensembles which also makes them likely agonists of pathological brain activity. Although large body of experimental data and theoretical considerations indicate that coupling neurons by electrical synapses promotes synchronous activity (and thus is potentially epileptogenic, some recent evidence questions the hypothesis of gap junctions being among purely epileptogenic factors. In particular, an expression of inter-neuronal gap junctions is often found to be higher after the experimentally induced seizures than before. Here we used a computational modeling approach to address the role of neuronal gap junctions in shaping the stability of a network to perturbations that are often associated with the onset of epileptic seizures. We show that under some circumstances, the addition of gap junctions can increase the dynamical stability of a network and thus suppress the collective electrical activity associated with seizures. This implies that the experimentally observed post-seizure additions of gap junctions could serve to prevent further escalations, suggesting furthermore that they are a consequence of an adaptive response of the neuronal network to the pathological activity. However, if the seizures are strong and persistent, our model predicts the existence of a critical tipping point after which additional gap junctions no longer suppress but strongly facilitate the escalation of epileptic seizures. Our results thus reveal a complex role of electrical coupling in relation to epileptiform events. Which dynamic scenario (seizure suppression or seizure escalation is ultimately adopted by the network depends critically on the strength and duration of seizures, in turn emphasizing the importance of temporal and causal aspects when linking gap junctions with epilepsy.

  7. THE DISTANCE EDUCATION TO PROMOTE CONTINUOUS LEARNING OF HEALTH PROFESSIONALS: REVIEW

    Directory of Open Access Journals (Sweden)

    Lívia Lima Ferraz

    2013-03-01

    Full Text Available The results of many articles and researches showed thatemploymenthavean importantrolefor continuous learning. The main factors that made possible this continuous education were:the technology information advanced and distance education flexibilities.Theevolutionofon-line continuing education helps the health care professionals development manyfundamental learning skillsas self-assessment and self-criticism.Therefore, this articlesobjective is to identify howpublic policiescould promote continuous learning of healthprofessionals through distance education(DEand the contributions of this education formatfor transformationhealth activities.In conclusion, the results were that distance education(DE was an important strategy for permanent education, because(DEdevelopments goodskills of learning and breaksterritories barriers. Wherefore, distance education became aneffective learning format

  8. Maximum nondiffracting propagation distance of aperture-truncated Airy beams

    Science.gov (United States)

    Chu, Xingchun; Zhao, Shanghong; Fang, Yingwu

    2018-05-01

    Airy beams have called attention of many researchers due to their non-diffracting, self-healing and transverse accelerating properties. A key issue in research of Airy beams and its applications is how to evaluate their nondiffracting propagation distance. In this paper, the critical transverse extent of physically realizable Airy beams is analyzed under the local spatial frequency methodology. The maximum nondiffracting propagation distance of aperture-truncated Airy beams is formulated and analyzed based on their local spatial frequency. The validity of the formula is verified by comparing the maximum nondiffracting propagation distance of an aperture-truncated ideal Airy beam, aperture-truncated exponentially decaying Airy beam and exponentially decaying Airy beam. Results show that the formula can be used to evaluate accurately the maximum nondiffracting propagation distance of an aperture-truncated ideal Airy beam. Therefore, it can guide us to select appropriate parameters to generate Airy beams with long nondiffracting propagation distance that have potential application in the fields of laser weapons or optical communications.

  9. Reflective journaling: developing an online journal for distance education.

    Science.gov (United States)

    Kessler, Penny D; Lund, Carole H

    2004-01-01

    Reflective journal writing can be a useful heuristic tool to foster critical thinking skills and develop reflective clinical practice in nursing. When combined with a distance education delivery format, the online journal helps to leverage the strengths of reflective learning with educational technology as well as provide a seamless record of learning outcomes across the curriculum. The authors discuss the incorporation of an online reflective journal into a distance education clinical course and provide guidelines for educators considering a similar approach.

  10. Institutional Continuity and Distance Learning: A Symbiotic Relationship

    Science.gov (United States)

    Bates, Rodger

    2013-01-01

    Universities and colleges have been developing institutional continuity plans to protect their ability to function within an environment of increasing uncertainties caused by natural and man-made disasters and events. Within the academic context, distance learning strategies have emerged as critical components for program continuity. This research…

  11. Distance of the image plane from metal surfaces

    International Nuclear Information System (INIS)

    Smith, N.V.; Chen, C.T.; Weinert, M.

    1989-01-01

    The data base of surface-state energies on the metals Cu, Ag, Au, Ni, Pd, and Pt is assembled and, with the aid of a simple model, is used to estimate the distance of the image plane and its trends from surface to surface and metal to metal. The model combines a nearly-free-electron representation of the crystal with a Jones-Jennings-Jepsen ansatz for the saturated image barrier. The projected bulk-band gaps are taken from published determinations. Constraints are placed on the surface barrier parameters by appeal to the results of self-consistent first-principles slab calculations. The general experimental trend observed is for the image-plane distance z 0 to decrease in the sequence (111) to (001) to (110), in the same sense but not as rapidly as z J , the distance of the effective jellium edge. This trend is rationalized using a simple model of the tail of the surface charge density. Typical values for z 0 -z J fall in the range -0.2 to +0.5 a.u., with the larger values occurring for the 3d metals Cu and Ni

  12. Critical points for finite Fibonacci chains of point delta-interactions and orthogonal polynomials

    International Nuclear Information System (INIS)

    De Prunele, E

    2011-01-01

    For a one-dimensional Schroedinger operator with a finite number n of point delta-interactions with a common intensity, the parameters are the intensity, the n - 1 intercenter distances and the mass. Critical points are points in the parameters space of the Hamiltonian where one bound state appears or disappears. The study of critical points for Hamiltonians with point delta-interactions arranged along a Fibonacci chain is shown to be closely related to the study of the so-called Fibonacci operator, a discrete one-dimensional Schroedinger-type operator, which occurs in the context of tight binding Hamiltonians. These critical points are the zeros of orthogonal polynomials previously studied in the context of special diatomic linear chains with elastic nearest-neighbor interaction. Properties of the zeros (location, asymptotic behavior, gaps, ...) are investigated. The perturbation series from the solvable periodic case is determined. The measure which yields orthogonality is investigated numerically from the zeros. It is shown that the transmission coefficient at zero energy can be expressed in terms of the orthogonal polynomials and their associated polynomials. In particular, it is shown that when the number of point delta-interactions is equal to a Fibonacci number minus 1, i.e. when the intervals between point delta-interactions form a palindrome, all the Fibonacci chains at critical points are completely transparent at zero energy. (paper)

  13. Mathematical analysis of the multiband BCS gap equations in superconductivity

    Science.gov (United States)

    Yang, Yisong

    2005-01-01

    In this paper, we present a mathematical analysis for the phonon-dominated multiband isotropic and anisotropic BCS gap equations at any finite temperature T. We establish the existence of a critical temperature T so that, when TT, the only nonnegative gap solution is the zero solution, representing the normal phase. Furthermore, when T=T, we prove that the only gap solution is the zero solution and that the positive gap solution depend on the temperature TMarkowitz-Kadanoff model and we prove that the presence of anisotropic fluctuations enhances T as in the single-band case. A special consequence of these results is that the half-unity exponent isotope effect may rigorously be proved in the multiband BCS theory, isotropic or anisotropic.

  14. Bridging the gap among healthcare workers and decision-makers ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Bridging the gap among healthcare workers and decision-makers through improved ... Through this project, researchers will build on insights gained from previous ... and identify the critical factors required for the scale-up and integration of the ...

  15. Electrical stimulation accelerates axonal and functional peripheral nerve regeneration across long gaps.

    Science.gov (United States)

    Haastert-Talini, Kirsten; Schmitte, Ruth; Korte, Nele; Klode, Dorothee; Ratzka, Andreas; Grothe, Claudia

    2011-04-01

    Short-term low-frequency electrical stimulation (ESTIM) of proximal peripheral nerve stumps prior to end-to-end coaptation or tubular bridging of small distances has been reported to increase preferential motor reinnervation and functional motor recovery in animal models and human patients undergoing carpal tunnel release surgery. We investigated the effects of ESTIM on regeneration across rat sciatic nerve gaps, which exceed distances that allow spontaneous regeneration. Three different reconstruction approaches were combined with ESTIM in the experimental groups. Nerve gaps (13 mm) were bridged using (I) nerve autotransplantation, (II) transplantation of differentially filled silicone tubes, or (III) transplantation of tubular grafts containing fibroblast growth factor-2 overexpressing Schwann cells (SCs) for gene therapy. The regeneration outcome was followed for up to 8 weeks, and functionally as well as histomorphometrically analyzed in comparison to non-stimulated control groups. Combining ESTIM with nerve autotransplantation significantly increased the nerve fiber density in the regenerated nerve, and the grade of functional recovery as detected by electrodiagnostic recordings from the gastrocnemius muscle. The combination of ESTIM with transplantation of naïve SCs increased the regeneration of gap-bridging nerve tissue. Although macroscopic tissue regeneration was not further improved after combining ESTIM with FGF-2(21/23-kD) gene therapy, the latter resulted in a high rate of regenerated nerves that functionally reconnected to the target muscle. Based on our results, brief ESTIM shows high potential to accelerate axonal as well as functional (motor and sensory) outcomes in the clinical setting of peripheral nerve gap reconstruction in human patients.

  16. Two S-wave gap symmetry for single crystals of the superconductor BaFe1.8Co0.2As2

    International Nuclear Information System (INIS)

    Choi, Ki-Young; Kim, Soo Hyun; Choi, Changho; Jung, Myung-Hwa; Wang, X.F.; Chen, X.H.; Noh, Jae Dong; Lee, Sung-IK

    2010-01-01

    To clarify the gap structure of the iron-pnictide superconductors, we synthesized optimally doped single crystals of BaFe 1.8 Co 0.2 As 2 , which had a critical temperature, T c , of 23.6 K. The initial M-H curve was used to find the lower critical field, H c1 . The full range of the temperature dependence of H c1 was explained by using a two S-wave gap symmetry. We estimate the two gap as Δ 1 (0) = 1.64 ± 0.2 meV for the small gap and Δ 2 (0) = 6.20 ± 0.2 meV for the large gap.

  17. Critical Proximity as a Methodological Move in Techno-Anthropology

    DEFF Research Database (Denmark)

    Birkbak, Andreas; Petersen, Morten Krogh; Elgaard Jensen, Torben

    2015-01-01

    proximity.’ Critical proximity offers an alternative to critical distance, especially with respect to avoiding premature references to abstract panoramas such as democratization and capitalist exploitation in the quest to conduct ‘critical’ analysis. Critical proximity implies, instead, granting the beings...

  18. Regional energy efficiency, carbon emission performance and technology gaps in China: A meta-frontier non-radial directional distance function analysis

    International Nuclear Information System (INIS)

    Yao, Xin; Zhou, Hongchen; Zhang, Aizhen; Li, Aijun

    2015-01-01

    At present, China is the largest primary energy consumer and carbon emitter in the world. Meantime, China is a large transitional economy with significant regional gaps. Against such backgrounds, the calculated results of energy and carbon performance indicators may be biased, without considering heterogeneity across regions. To this end, after incorporating region-heterogeneity, this paper provides detailed information, regarding energy efficiency, carbon emission performance and the potential of carbon emission reductions from regional perspectives, which may be important and useful for policy makers. Our main findings are as follows. Firstly, there is significant group-heterogeneity across regions in China, in terms of energy efficiency and carbon emission performance. Secondly, there are no considerable differences between total-factor and single-factor performance indices, since there is limited substitutability between energy inputs and other production inputs. Finally, significant carbon emission reductions can be made by “catching up” for regions with low energy efficiency and carbon emission performance. Looking ahead, the Chinese government should adopt measures to promote improvements in terms of energy efficiency and carbon emission performance in the short term. -- Highlights: •We adopt a meta-frontier non-radial directional distance function analysis. •We provide detailed information regarding energy and carbon emission performance. •We find that there is significant region-heterogeneity in China. •There are no large differences between total- and single-factor performance indices. •It can make great contributions to carbon emission reductions by “catching up”

  19. Cultural Distance and the Performance of International Joint Ventures

    DEFF Research Database (Denmark)

    Christoffersen, Jeppe; Globerman, Steven; Nielsen, Bo Bernhard

    2013-01-01

    This study provides a critical summary and assessment of the empirical literature on the relationship between cultural distance and the performance of international joint ventures (IJVs) based on studies published over the period 1993-2008. The existing literature reports inconsistent and largely...

  20. Mind the gap: a flow instability controlled by particle-surface distance

    Science.gov (United States)

    Driscoll, Michelle; Delmotte, Blaise; Youssef, Mena; Sacanna, Stefano; Donev, Aleksandar; Chaikin, Paul

    2016-11-01

    Does a rotating particle always spin in place? Not if that particle is near a surface: rolling leads to translational motion, as well as very strong flows around the particle, even quite far away. These large advective flows strongly couple the motion of neighboring particles, giving rise to strong collective effects in groups of rolling particles. Using a model experimental system, weakly magnetic colloids driven by a rotating magnetic field, we observe that driving a compact group of microrollers leads to a new kind of flow instability. First, an initially uniformly-distributed strip of particles evolves into a shock structure, and then it becomes unstable, emitting fingers with a well-defined wavelength. Using 3D large-scale simulations in tandem with our experiments, we find that the instability wavelength is controlled not by the driving torque or the fluid viscosity, but a geometric parameter: the microroller's distance above the container floor. Furthermore, we find that the instability dynamics can be reproduced using only one ingredient: hydrodynamic interactions near a no-slip boundary.

  1. The ecological impact of city lighting scenarios: exploring gap crossing thresholds for urban bats.

    Science.gov (United States)

    Hale, James D; Fairbrass, Alison J; Matthews, Thomas J; Davies, Gemma; Sadler, Jon P

    2015-02-02

    As the global population urbanizes, dramatic changes are expected in city lighting and the urban form, which may threaten the functioning of urban ecosystems and the services they deliver. However, little is known about the ecological impact of lighting in different urban contexts. Movement is an important ecological process that can be disrupted by artificial lighting. We explored the impact of lighting on gap crossing for Pipistrellus pipistrellus, a species of bat (Chiroptera) common within UK cities. We aimed to determine whether the probability of crossing gaps in tree cover varied with crossing distance and lighting level, through stratified field surveys. We then used the resulting data on barrier thresholds to model the landscape resistance due to lighting across an entire city and explored the potential impact of scenarios for future changes to street lighting. The level of illumination required to create a barrier effect reduced as crossing distance increased. For those gaps where crossing was recorded, bats selected the darker parts of gaps. Heavily built parts of the case study city were associated with large and brightly lit gaps, and spatial models indicate movement would be highly restricted in these areas. Under a scenario for brighter street lighting, the area of accessible land cover was further reduced in heavily built parts of the city. We believe that this is the first study to demonstrate how lighting may create resistance to species movement throughout an entire city. That connectivity in urban areas is being disrupted for a relatively common species raises questions about the impacts on less tolerant groups and the resilience of bat communities in urban centres. However, this mechanistic approach raises the possibility that some ecological function could be restored in these areas through the strategic dimming of lighting and narrowing of gaps. © 2015 The Authors. Global Change Biology Published by John Wiley & Sons Ltd.

  2. Anisotropic lattice expansion of three-dimensional colloidal crystals and its impact on hypersonic phonon band gaps.

    Science.gov (United States)

    Wu, Songtao; Zhu, Gaohua; Zhang, Jin S; Banerjee, Debasish; Bass, Jay D; Ling, Chen; Yano, Kazuhisa

    2014-05-21

    We report anisotropic expansion of self-assembled colloidal polystyrene-poly(dimethylsiloxane) crystals and its impact on the phonon band structure at hypersonic frequencies. The structural expansion was achieved by a multistep infiltration-polymerization process. Such a process expands the interplanar lattice distance 17% after 8 cycles whereas the in-plane distance remains unaffected. The variation of hypersonic phonon band structure induced by the anisotropic lattice expansion was recorded by Brillouin measurements. In the sample before expansion, a phononic band gap between 3.7 and 4.4 GHz is observed; after 17% structural expansion, the gap is shifted to a lower frequency between 3.5 and 4.0 GHz. This study offers a facile approach to control the macroscopic structure of colloidal crystals with great potential in designing tunable phononic devices.

  3. C3 toxin and poly-DL-lactide-ε-caprolactone conduits in the critically damaged peripheral nervous system: a combined therapeutic approach.

    Science.gov (United States)

    Leibig, Nico; Boyle, Veronika; Kraus, Daniel; Stark, Gerhard Bjoern; Penna, Vincenzo

    2015-03-01

    Peripheral nerve regeneration over longer distances through conduits is limited. In the presented study, critical size nerve gap bridging with a poly-DL-lactide-ε-caprolactone (PLC) conduit was combined with application of C3 toxin to facilitate axonal sprouting. The PLC filled with fibrin (n = 10) and fibrin gel loaded with 1-μg C3-C2I and 2-μg C2II (n = 10) were compared to autologous nerve grafts (n = 10) in a 15-mm sciatic nerve gap lesion model of the rat. Functional and electrophysiological analyses were performed before histological evaluation. Evaluation of motor function and nerve conduction velocity at 16 weeks revealed no differences between the groups. All histological parameters and muscle weight were significantly elevated in nerve graft group. No differences were observed in both PLC groups. The PLCs are permissive for nerve regeneration over a 15-mm defect in rats. Intraluminal application of C3 toxin did not lead to significant enhancement of nerve sprouting.

  4. The Digital Divide in Developing Countries: A Case for Distance Education

    Directory of Open Access Journals (Sweden)

    Kenneth E. Paprock

    2006-12-01

    Full Text Available Although distance education is catching up in almost all countries in the world, it is still little known and less studied in many of the developing countries. Given such a lack of coverage even in the Western educational literature, the possibilities of finding in-depth exchanges concerning distance education in developing countries are very limited. This presentation presents the existing 'digital gap' in the world, and focuses on three important barriers to distance education or learning are: 1 the lack of resources 2 lack of infrastructures, and 3 lack of recurrent funding necessary to acquire or develop appropriate software and courseware on a continuous basis, and maintain, service and replace the equipment. Technologists and educators need to enter the developing world, study the market and then modify their wares according to local needs with the help of local industry and labor-force. This is one important way of building meaningful collaborations and partnerships between the developed and developing countries.

  5. Tunable electric properties of bilayer InSe with different interlayer distances and external electric field

    Science.gov (United States)

    Shang, Jimin; Pan, Longfei; Wang, Xiaoting; Li, Jingbo; Wei, Zhongming

    2018-03-01

    Using density functional theory we explore the band structure of bilayer Indium selenide (InSe), and we find that the van der Waals interaction has significant effects on the electric and optical properties. We then explore the tuning electronic properties by different interlayer distances and by an external vertical electric field. Our results demonstrate that the band gaps of bilayer InSe can be continuously tuned by different interlayer coupling. With decreasing interlayer distances, the tunable band gaps of bilayer decrease linearly, owing to the enhancement of the interlayer interaction. Additionally, the band structure of bilayer InSe under external vertical fields is discussed. The presence of a small external electric field can make a new spatial distribution of electron-hole pairs. A well separation based on the electrons and holes, localized in different layers can be obtained using this easy method. These properties of bilayer InSe indicates potential applications in designing new optoelectronic devices.

  6. Effectiveness of Asynchronous Reference Services for Distance Learning Students within Florida's Community College System

    Science.gov (United States)

    Profeta, Patricia C.

    2007-01-01

    The provision of equitable library services to distance learning students emerged as a critical area during the 1990s. Library services available to distance learning students included digital reference and instructional services, remote access to online research tools, database and research tutorials, interlibrary loan, and document delivery.…

  7. GAP OPENING BY EXTREMELY LOW-MASS PLANETS IN A VISCOUS DISK

    International Nuclear Information System (INIS)

    Duffell, Paul C.; MacFadyen, Andrew I.

    2013-01-01

    By numerically integrating the compressible Navier-Stokes equations in two dimensions, we calculate the criterion for gap formation by a very low mass (q ∼ 10 –4 ) protoplanet on a fixed orbit in a thin viscous disk. In contrast with some previously proposed gap-opening criteria, we find that a planet can open a gap even if the Hill radius is smaller than the disk scale height. Moreover, in the low-viscosity limit, we find no minimum mass necessary to open a gap for a planet held on a fixed orbit. In particular, a Neptune-mass planet will open a gap in a minimum mass solar nebula with suitably low viscosity (α ∼ –4 ). We find that the mass threshold scales as the square root of viscosity in the low mass regime. This is because the gap width for critical planet masses in this regime is a fixed multiple of the scale height, not of the Hill radius of the planet.

  8. A Begrudging, Recalcitrant Academic Observes What She's Learning: Distance Learning in Leadership Formation

    Science.gov (United States)

    Hess, Lisa M.

    2014-01-01

    Neither advocacy nor condemnation of distance learning, this essay offers observations and critical reflection on four years' longitudinal engagement with distance learning pedagogies for formation in higher theological education. Instead, readers are invited to curiosity, communal-institutional discernment, and intense ambivalence.…

  9. Japanese consumer preferences for milk certified with the good agricultural practice(GAP) label.

    Science.gov (United States)

    Aizaki, Hideo; Nanseki, Teruaki; Zhou, Hui

    2013-01-01

    This study examined Japanese consumers' valuation of a good agricultural practice (GAP) label on packaged milk and investigated the effect of detailed GAP information on valuation. A total of 624 Japanese consumers were asked to select their most preferred milk through an online survey. The milk was assumed to have three attributes: the GAP label, Hazard Analysis and Critical Control Points certification, and price. The results showed that consumers' valuation of GAP was significantly positive. Although providing additional GAP information to a respondent who was aware of GAP and what it means had a positive effect on the consumers' valuation of GAP, provision of this information had no effect if the respondent knew about GAP either moderately or slightly, and had a negative effect if the respondent did not know about GAP at all. To increase broad consumer awareness and valuation of GAP, it is important to provide GAP information according to the requirements of consumers. © 2012 The Authors. Animal Science Journal © 2012 Japanese Society of Animal Science.

  10. Safety distance for preventing hot particle ignition of building insulation materials

    OpenAIRE

    Jiayun Song; Supan Wang; Haixiang Chen

    2014-01-01

    Trajectories of flying hot particles were predicted in this work, and the temperatures during the movement were also calculated. Once the particle temperature decreased to the critical temperature for a hot particle to ignite building insulation materials, which was predicted by hot-spot ignition theory, the distance particle traveled was determined as the minimum safety distance for preventing the ignition of building insulation materials by hot particles. The results showed that for sphere ...

  11. Pulse EPR distance measurements to study multimers and multimerisation

    Science.gov (United States)

    Ackermann, Katrin; Bode, Bela E.

    2018-06-01

    Pulse dipolar electron paramagnetic resonance (PD-EPR) has become a powerful tool for structural biology determining distances on the nanometre scale. Recent advances in hardware, methodology, and data analysis have widened the scope to complex biological systems. PD-EPR can be applied to systems containing lowly populated conformers or displaying large intrinsic flexibility, making them all but intractable for cryo-electron microscopy and crystallography. Membrane protein applications are of particular interest due to the intrinsic difficulties for obtaining high-resolution structures of all relevant conformations. Many drug targets involved in critical cell functions are multimeric channels or transporters. Here, common approaches for introducing spin labels for PD-EPR cause the presence of more than two electron spins per multimeric complex. This requires careful experimental design to overcome detrimental multi-spin effects and to secure sufficient distance resolution in presence of multiple distances. In addition to obtaining mere distances, PD-EPR can also provide information on multimerisation degrees allowing to study binding equilibria and to determine dissociation constants.

  12. Quality Management In Open And Distance Learning Situation ...

    African Journals Online (AJOL)

    The quality of Nigerian Education has been criticized from the lowest to the highest level of the system. It has been discussed in various mass media. People have expressed the need to raise the quality of our education in the country. This paper looks at the concepts of quality, management and open and distance learning.

  13. Gaps in monitoring during oral anticoagulation: insights into care transitions, monitoring barriers, and medication nonadherence.

    Science.gov (United States)

    Rose, Adam J; Miller, Donald R; Ozonoff, Al; Berlowitz, Dan R; Ash, Arlene S; Zhao, Shibei; Reisman, Joel I; Hylek, Elaine M

    2013-03-01

    Among patients receiving oral anticoagulation, a gap of > 56 days between international normalized ratio tests suggests loss to follow-up that could lead to poor anticoagulation control and serious adverse events. We studied long-term oral anticoagulation care for 56,490 patients aged 65 years and older at 100 sites of care in the Veterans Health Administration. We used the rate of gaps in monitoring per patient-year to predict percentage time in therapeutic range (TTR) at the 100 sites. Many patients (45%) had at least one gap in monitoring during an average of 1.6 years of observation; 5% had two or more gaps per year. The median gap duration was 74 days (interquartile range, 62-107). The average TTR for patients with two or more gaps per year was 10 percentage points lower than for patients without gaps (P < .001). Patient-level predictors of gaps included nonwhite race, area poverty, greater distance from care, dementia, and major depression. Site-level gaps per patient-year varied from 0.19 to 1.78; each one-unit increase was associated with a 9.2 percentage point decrease in site-level TTR (P < .001). Site-level gap rates varied widely within an integrated care system. Sites with more gaps per patient-year had worse anticoagulation control. Strategies to address and reduce gaps in monitoring may improve anticoagulation control.

  14. Social Distance and Community Attitudes Towards People with Psycho-Social Disabilities in Uttarakhand, India.

    Science.gov (United States)

    Mathias, K; Kermode, M; Goicolea, I; Seefeldt, L; Shidhaye, R; San Sebastian, M

    2018-04-01

    Stigma is an important contributor to the large treatment gap for people with mental and psycho-social disabilities (PPSD) in India. Social distance as assessed by willingness to engage in relationships with PPSD is a proxy measure of stigma and potential discrimination. In North India, investigations of community attitudes towards PPSD have been limited. To describe attitudes towards people with depression and psychosis, a community sample of 960 adults in Dehradun district, India from 30 randomised clusters, was surveyed using a validated tool to assess social distance, beliefs and attitudes related to mental illness. Participants preferred greater social distance from a person with psychosis than a person with depression. Beliefs and attitudes around mental illness were diverse reflecting a wide spread of belief frameworks. After controlling for confounding, there was increased social distance among people who believed PPSD were dangerous. Factors that reduced social distance included familiarity with PPSD, and belief that PPSD can recover. Attitudes to PPSD, stigma and social distance are complex and likely to require complex responses that include promoting awareness of mental health and illness, direct contact with PPSD and increasing access to care for PPSD.

  15. Scattering and short-distance properties in field theory models

    International Nuclear Information System (INIS)

    Iagolnitzer, D.

    1987-01-01

    The aim of constructive field theory is not only to define models but also to establish their general properties of physical interest. We here review recent works on scattering and on short-distance properties for weakly coupled theories with mass gap such as typically P(φ) in dimension 2, φ 4 in dimension 3 and the (renormalizable, asymptotically free) massive Gross-Neveu (GN) model in dimension 2. Many of the ideas would apply similarly to other (possibly non renormalizable) theories that might be defined in a similar way via phase-space analysis

  16. The prototype GAPS (pGAPS) experiment

    International Nuclear Information System (INIS)

    Mognet, S.A.I.; Aramaki, T.; Bando, N.; Boggs, S.E.; Doetinchem, P. von; Fuke, H.; Gahbauer, F.H.; Hailey, C.J.; Koglin, J.E.; Madden, N.; Mori, K.; Okazaki, S.; Ong, R.A.; Perez, K.M.; Tajiri, G.; Yoshida, T.; Zweerink, J.

    2014-01-01

    The General Antiparticle Spectrometer (GAPS) experiment is a novel approach for the detection of cosmic ray antiparticles. A prototype GAPS (pGAPS) experiment was successfully flown on a high-altitude balloon in June of 2012. The goals of the pGAPS experiment were: to test the operation of lithium drifted silicon (Si(Li)) detectors at balloon altitudes, to validate the thermal model and cooling concept needed for engineering of a full-size GAPS instrument, and to characterize cosmic ray and X-ray backgrounds. The instrument was launched from the Japan Aerospace Exploration Agency's (JAXA) Taiki Aerospace Research Field in Hokkaido, Japan. The flight lasted a total of 6 h, with over 3 h at float altitude (∼33km). Over one million cosmic ray triggers were recorded and all flight goals were met or exceeded

  17. Distance education: the humanization of technology

    Science.gov (United States)

    Voelzke, Marcos Rincon; Rodrigues Ferreira, Orlando

    2015-08-01

    The Distance Education [DE] presents significant growth in graduates and postgraduates programs. Regarding this fact, new challenges arise and others must be considered, as the generation gap between digital immigrants and digital natives, the establishment of a population increasingly accustomed to Information and Communication Technologies [ICT] and teaching methodologies that should be used and developed. Vygotsky’s model of social interaction related to mediation can and should be used in DE, and concerning historical, social and cultural approaches affecting Brazilian reality, Paulo Freire is still up-to-date, integrating humanization into the use of ICT. This work only proceeds with analyses of these elements, being an excerpt of the master’s dissertation of one of the authors [Ferreira], under the guidance of another [Voelzke].

  18. Spark gap produced plasma diagnostics

    International Nuclear Information System (INIS)

    Chang, H.Y.

    1990-01-01

    A Spark Gap (Applied voltage : 2-8KV, Capacitor : 4 Micro F. Dia of the tube : 1 inch, Electrode distance : .3 ∼.5 inch) was made to generate a small size dynamic plasma. To measure the plasma density and temperature as a function of time and position, we installed and have been installing four detection systems - Mach-Zehnder type Interferometer for the plasma refractivity, Expansion speed detector using two He-Ne laser beams, Image Processing using Lens and A Optical-Fiber Array for Pointwise Radiation Sensing, Faraday Rotation of a Optical Fiber to measure the azimuthal component of B-field generated by the plasma drift. These systems was used for the wire explosion diagnostics, and can be used for the Laser driven plasma also

  19. Application of the ultrametric distance to portfolio taxonomy. Critical approach and comparison with other methods

    Science.gov (United States)

    Skórnik-Pokarowska, Urszula; Orłowski, Arkadiusz

    2004-12-01

    We calculate the ultrametric distance between the pairs of stocks that belong to the same portfolio. The ultrametric distance allows us to distinguish groups of shares that are related. In this way, we can construct a portfolio taxonomy that can be used for constructing an efficient portfolio. We also construct a portfolio taxonomy based not only on stock prices but also on economic indices such as liquidity ratio, debt ratio and sales profitability ratio. We show that a good investment strategy can be obtained by applying to the portfolio chosen by the taxonomy method the so-called Constant Rebalanced Portfolio.

  20. System Predicts Critical Runway Performance Parameters

    Science.gov (United States)

    Millen, Ernest W.; Person, Lee H., Jr.

    1990-01-01

    Runway-navigation-monitor (RNM) and critical-distances-process electronic equipment designed to provide pilot with timely and reliable predictive navigation information relating to takeoff, landing and runway-turnoff operations. Enables pilot to make critical decisions about runway maneuvers with high confidence during emergencies. Utilizes ground-referenced position data only to drive purely navigational monitor system independent of statuses of systems in aircraft.

  1. The prototype GAPS (pGAPS) experiment

    Energy Technology Data Exchange (ETDEWEB)

    Mognet, S.A.I., E-mail: mognet@astro.ucla.edu [University of California, Los Angeles, CA 90095 (United States); Aramaki, T. [Columbia University, New York, NY 10027 (United States); Bando, N. [Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (ISAS/JAXA), Sagamihara, Kanagawa 252-5210 (Japan); Boggs, S.E.; Doetinchem, P. von [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States); Fuke, H. [Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (ISAS/JAXA), Sagamihara, Kanagawa 252-5210 (Japan); Gahbauer, F.H.; Hailey, C.J.; Koglin, J.E.; Madden, N. [Columbia University, New York, NY 10027 (United States); Mori, K.; Okazaki, S. [Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (ISAS/JAXA), Sagamihara, Kanagawa 252-5210 (Japan); Ong, R.A. [University of California, Los Angeles, CA 90095 (United States); Perez, K.M.; Tajiri, G. [Columbia University, New York, NY 10027 (United States); Yoshida, T. [Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (ISAS/JAXA), Sagamihara, Kanagawa 252-5210 (Japan); Zweerink, J. [University of California, Los Angeles, CA 90095 (United States)

    2014-01-21

    The General Antiparticle Spectrometer (GAPS) experiment is a novel approach for the detection of cosmic ray antiparticles. A prototype GAPS (pGAPS) experiment was successfully flown on a high-altitude balloon in June of 2012. The goals of the pGAPS experiment were: to test the operation of lithium drifted silicon (Si(Li)) detectors at balloon altitudes, to validate the thermal model and cooling concept needed for engineering of a full-size GAPS instrument, and to characterize cosmic ray and X-ray backgrounds. The instrument was launched from the Japan Aerospace Exploration Agency's (JAXA) Taiki Aerospace Research Field in Hokkaido, Japan. The flight lasted a total of 6 h, with over 3 h at float altitude (∼33km). Over one million cosmic ray triggers were recorded and all flight goals were met or exceeded.

  2. Engineering Surface Critical Behavior of (2 +1 )-Dimensional O(3) Quantum Critical Points

    Science.gov (United States)

    Ding, Chengxiang; Zhang, Long; Guo, Wenan

    2018-06-01

    Surface critical behavior (SCB) refers to the singularities of physical quantities on the surface at the bulk phase transition. It is closely related to and even richer than the bulk critical behavior. In this work, we show that three types of SCB universality are realized in the dimerized Heisenberg models at the (2 +1 )-dimensional O(3) quantum critical points by engineering the surface configurations. The ordinary transition happens if the surface is gapped in the bulk disordered phase, while the gapless surface state generally leads to the multicritical special transition, even though the latter is precluded in classical phase transitions because the surface is in the lower critical dimension. An extraordinary transition is induced by the ferrimagnetic order on the surface of the staggered Heisenberg model, in which the surface critical exponents violate the results of the scaling theory and thus seriously challenge our current understanding of extraordinary transitions.

  3. Distance Education and Corporate Training in Brazil: Regulations and interrelationships

    Directory of Open Access Journals (Sweden)

    Stella C. S. Porto

    2008-06-01

    Full Text Available Distance education in Brazil has evolved more slowly than distance education offerings in other developing countries. This is because all aspects of Brazil’s publicly-funded educational system are excessively regulated, highly bureaucratic, and tightly centralized. Such highly centralized bureaucracy and strict control has resulted in tremendous hurdles that work to thwart the adoption, provision, and diffusion of distance education. This is not good news: Like many developing countries, Brazil is also characterized by wide gaps in wealth distribution, with 20 percent of its population functionally illiterate and living below the poverty line. Distance education, therefore, could be used to help train Brazil’s citizens. Brazil’s emerging status in the global economy, however, is generating enormous opportunities that are fueling demand for change. For example, in their quest to be competitive in the emerging global economy, Brazil’s corporate sector has addressed this challenge by establishing corporate universities to train and educate their employees; much of this corporate training and education takes place online and at a distance. The established and emerging educational opportunities provided by Brazil’s corporate sector, in turn, is fuelling the demand for the provision of distance education throughout Brazil. Indeed, most Brazilians are ready for distance education. Many Brazilian households own television sets and cellular telephones, and its expanding communication infrastructure has capacity to support distance and continuing education models. Moreover, this capacity is currently being used by Brazil’s rapidly expanding corporate university sector. In spite of Brazil’s emergence in the global marketplace and its private-sector educational success stories, Brazil’s public educational institutions have not kept pace. This is due to Brazil’s long-standing stringent regulation of its public education sector. Recent

  4. The potential of critical feminist citizenship frameworks for ...

    African Journals Online (AJOL)

    There is a paucity of South African literature that uses feminist critical approaches as a conceptual tool to examine intersections of social justice and citizenship. This article aims to address this gap by examining the potential of critical feminist approaches to transform concepti ons of citizenship in higher education. It outlines ...

  5. Customizing Laboratory Information Systems: Closing the Functionality Gap.

    Science.gov (United States)

    Gershkovich, Peter; Sinard, John H

    2015-09-01

    Highly customizable laboratory information systems help to address great variations in laboratory workflows, typical in Pathology. Often, however, built-in customization tools are not sufficient to add all of the desired functionality and improve systems interoperability. Emerging technologies and advances in medicine often create a void in functionality that we call a functionality gap. These gaps have distinct characteristics—a persuasive need to change the way a pathology group operates, the general availability of technology to address the missing functionality, the absence of this technology from your laboratory information system, and inability of built-in customization tools to address it. We emphasize the pervasive nature of these gaps, the role of pathology informatics in closing them, and suggest methods on how to achieve that. We found that a large number of the papers in the Journal of Pathology Informatics are concerned with these functionality gaps, and an even larger proportion of electronic posters and abstracts presented at the Pathology Informatics Summit conference each year deal directly with these unmet needs in pathology practice. A rapid, continuous, and sustainable approach to closing these gaps is critical for Pathology to provide the highest quality of care, adopt new technologies, and meet regulatory and financial challenges. The key element of successfully addressing functionality gaps is gap ownership—the ability to control the entire pathology information infrastructure with access to complementary systems and components. In addition, software developers with detailed domain expertise, equipped with right tools and methodology can effectively address these needs as they emerge.

  6. Hyper-active gap filling

    Directory of Open Access Journals (Sweden)

    Akira eOmaki

    2015-04-01

    Full Text Available Much work has demonstrated that speakers of verb-final languages are able to construct rich syntactic representations in advance of verb information. This may reflect general architectural properties of the language processor, or it may only reflect a language-specific adaptation to the demands of verb-finality. The present study addresses this issue by examining whether speakers of a verb-medial language (English wait to consult verb transitivity information before constructing filler-gap dependencies, where internal arguments are fronted and hence precede the verb. This configuration makes it possible to investigate whether the parser actively makes representational commitments on the gap position before verb transitivity information becomes available. A key prediction of the view that rich pre-verbal structure-building is a general architectural property is that speakers of verb-medial languages should predictively construct dependencies in advance of verb transitivity information, and therefore that disruption should be observed when the verb has intransitive subcategorization frames that are incompatible with the predicted structure. In three reading experiments (self-paced and eye-tracking that manipulated verb transitivity, we found evidence for reading disruption when the verb was intransitive, although no such reading difficulty was observed when the critical verb was embedded inside a syntactic island structure, which blocks filler-gap dependency completion. These results are consistent with the hypothesis that in English, as in verb-final languages, information from preverbal NPs is sufficient to trigger active dependency completion without having access to verb transitivity information.

  7. Hyper-active gap filling.

    Science.gov (United States)

    Omaki, Akira; Lau, Ellen F; Davidson White, Imogen; Dakan, Myles L; Apple, Aaron; Phillips, Colin

    2015-01-01

    Much work has demonstrated that speakers of verb-final languages are able to construct rich syntactic representations in advance of verb information. This may reflect general architectural properties of the language processor, or it may only reflect a language-specific adaptation to the demands of verb-finality. The present study addresses this issue by examining whether speakers of a verb-medial language (English) wait to consult verb transitivity information before constructing filler-gap dependencies, where internal arguments are fronted and hence precede the verb. This configuration makes it possible to investigate whether the parser actively makes representational commitments on the gap position before verb transitivity information becomes available. A key prediction of the view that rich pre-verbal structure building is a general architectural property is that speakers of verb-medial languages should predictively construct dependencies in advance of verb transitivity information, and therefore that disruption should be observed when the verb has intransitive subcategorization frames that are incompatible with the predicted structure. In three reading experiments (self-paced and eye-tracking) that manipulated verb transitivity, we found evidence for reading disruption when the verb was intransitive, although no such reading difficulty was observed when the critical verb was embedded inside a syntactic island structure, which blocks filler-gap dependency completion. These results are consistent with the hypothesis that in English, as in verb-final languages, information from preverbal noun phrases is sufficient to trigger active dependency completion without having access to verb transitivity information.

  8. A PC microsimulation of a gap acceptance model for turning left at a T-junction

    NARCIS (Netherlands)

    Schaap, Nina; Dijck, T.; van Arem, Bart; Morsink, Peter L.J.

    2009-01-01

    Vehicles are controlled by sub-behavioral models in a microsimulation model, this includes the gap acceptance model where the decision about how to cross a junction is made. The critical gap in these models must serve as a threshold value to accept or reject the space between two successive vehicles

  9. Nuclear criticality predictability

    International Nuclear Information System (INIS)

    Briggs, J.B.

    1999-01-01

    As a result of lots of efforts, a large portion of the tedious and redundant research and processing of critical experiment data has been eliminated. The necessary step in criticality safety analyses of validating computer codes with benchmark critical data is greatly streamlined, and valuable criticality safety experimental data is preserved. Criticality safety personnel in 31 different countries are now using the 'International Handbook of Evaluated Criticality Safety Benchmark Experiments'. Much has been accomplished by the work of the ICSBEP. However, evaluation and documentation represents only one element of a successful Nuclear Criticality Safety Predictability Program and this element only exists as a separate entity, because this work was not completed in conjunction with the experimentation process. I believe; however, that the work of the ICSBEP has also served to unify the other elements of nuclear criticality predictability. All elements are interrelated, but for a time it seemed that communications between these elements was not adequate. The ICSBEP has highlighted gaps in data, has retrieved lost data, has helped to identify errors in cross section processing codes, and has helped bring the international criticality safety community together in a common cause as true friends and colleagues. It has been a privilege to associate with those who work so diligently to make the project a success. (J.P.N.)

  10. Using Unmanned Aerial Vehicles (UAV to Quantify Spatial Gap Patterns in Forests

    Directory of Open Access Journals (Sweden)

    Stephan Getzin

    2014-07-01

    Full Text Available Gap distributions in forests reflect the spatial impact of man-made tree harvesting or naturally-induced patterns of tree death being caused by windthrow, inter-tree competition, disease or senescence. Gap sizes can vary from large (>100 m2 to small (<10 m2, and they may have contrasting spatial patterns, such as being aggregated or regularly distributed. However, very small gaps cannot easily be recorded with conventional aerial or satellite images, which calls for new and cost-effective methodologies of forest monitoring. Here, we used an unmanned aerial vehicle (UAV and very high-resolution images to record the gaps in 10 temperate managed and unmanaged forests in two regions of Germany. All gaps were extracted for 1-ha study plots and subsequently analyzed with spatially-explicit statistics, such as the conventional pair correlation function (PCF, the polygon-based PCF and the mark correlation function. Gap-size frequency was dominated by small gaps of an area <5 m2, which were particularly frequent in unmanaged forests. We found that gap distances showed a variety of patterns. However, the polygon-based PCF was a better descriptor of patterns than the conventional PCF, because it showed randomness or aggregation for cases when the conventional PCF showed small-scale regularity; albeit, the latter was only a mathematical artifact. The mark correlation function revealed that gap areas were in half of the cases negatively correlated and in the other half independent. Negative size correlations may likely be the result of single-tree harvesting or of repeated gap formation, which both lead to nearby small gaps. Here, we emphasize the usefulness of UAV to record forest gaps of a very small size. These small gaps may originate from repeated gap-creating disturbances, and their spatial patterns should be monitored with spatially-explicit statistics at recurring intervals in order to further insights into forest dynamics.

  11. Experiments investigating the effects of the accelerating gap voltage pulse on the ion focused (IFR) high current electron recirculators

    International Nuclear Information System (INIS)

    Mazarakis, M.G.; Smith, D.L.; Poukey, J.W.; Wagner, J.S.; Bennett, L.F.; Olson, W.R. Turnman, B.N.; Prestwich, K.R.; Wells, J.

    1991-01-01

    The lifetime of the Ion Focusing Regime (IFR) channel following the pulsing of the post-accelerating gaps is critical for an open-ended, spiral recirculating electron linear accelerator. It dictates the number of allowable beam recirculations through the gap. In the case of a racetrack configuration, its is significant but not as critical, since the presence of the electron beam focuses the ions and lengthens the lifetime of the ion channel. It was established that pulsing the accelerating gap perturbs the IFR channel. However, for the parameters studied, the lifetime is long enough to allow at least four beam recirculations in a spiral device. In addition, cusp fields positioned upstream and downstream from the gap prevent it from perturbing the IFR channel

  12. ADMS State of the Industry and Gap Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Agalgaonkar, Yashodhan P.; Marinovici, Maria C.; Vadari, Subramanian V.; Schneider, Kevin P.; Melton, Ronald B.

    2016-03-31

    An Advanced distribution management system (ADMS) is a platform for optimized distribution system operational management. This platform comprises of distribution management system (DMS) applications, supervisory control and data acquisition (SCADA), outage management system (OMS), and distributed energy resource management system (DERMS). One of the primary objectives of this work is to study and analyze several ADMS component and auxiliary systems. All the important component and auxiliary systems, SCADA, GISs, DMSs, AMRs/AMIs, OMSs, and DERMS, are discussed in this report. Their current generation technologies are analyzed, and their integration (or evolution) with an ADMS technology is discussed. An ADMS technology state of the art and gap analysis is also presented. There are two technical gaps observed. The integration challenge between the component operational systems is the single largest challenge for ADMS design and deployment. Another significant challenge noted is concerning essential ADMS applications, for instance, fault location, isolation, and service restoration (FLISR), volt-var optimization (VVO), etc. There are a relatively small number of ADMS application developers as ADMS software platform is not open source. There is another critical gap and while not being technical in nature (when compared the two above) is still important to consider. The data models currently residing in utility GIS systems are either incomplete or inaccurate or both. This data is essential for planning and operations because it is typically one of the primary sources from which power system model are created. To achieve the full potential of ADMS, the ability to execute acute Power Flow solution is an important pre-requisite. These critical gaps are hindering wider Utility adoption of an ADMS technology. The development of an open architecture platform can eliminate many of these barriers and also aid seamless integration of distribution Utility legacy systems with an

  13. Magnetic-field and temperature dependence of the energy gap in InN nanobelt

    Directory of Open Access Journals (Sweden)

    K. Aravind

    2012-03-01

    Full Text Available We present tunneling measurements on an InN nanobelt which shows signatures of superconductivity. Superconducting transition takes place at temperature of 1.3K and the critical magnetic field is measured to be about 5.5kGs. The energy gap extrapolated to absolute temperature is about 110μeV. As the magnetic field is decreased to cross the critical magnetic field, the device shows a huge zero-bias magnetoresistance ratio of about 400%. This is attributed to the suppression of quasiparticle subgap tunneling in the presence of superconductivity. The measured magnetic-field and temperature dependence of the superconducting gap agree well with the reported dependences for conventional metallic superconductors.

  14. Robust band gap and half-metallicity in graphene with triangular perforations

    DEFF Research Database (Denmark)

    Gregersen, Søren Schou; Power, Stephen; Jauho, Antti-Pekka

    2016-01-01

    Ideal graphene antidot lattices are predicted to show promising band gap behavior (i.e., EG ≅ 500 meV) under carefully specified conditions. However, for the structures studied so far this behavior is critically dependent on superlattice geometry and is not robust against experimentally realistic...... disorders. Here we study a rectangular array of triangular antidots with zigzag edge geometries and show that their band gap behavior qualitatively differs from the standard behavior which is exhibited, e.g., by rectangular arrays of armchair-edged triangles. In the spin unpolarized case, zigzag......-edged antidots give rise to large band gaps compared to armchair-edged antidots, irrespective of the rules which govern the existence of gaps in armchair-edged antidot lattices. In addition the zigzag-edged antidots appear more robust than armchair-edged antidots in the presence of geometrical disorder...

  15. Planning and Implementing a Public Health Professional Distance Learning Program

    Science.gov (United States)

    Escoffery, Cam; Leppke, Allison M.; Robinson, Kara B.; Mettler, Erik P.; Miner, Kathleen R.; Smith, Iris

    2005-01-01

    Training of public health professionals through web-based technology is rapidly increasing. This article describes one school of public health's effort to establish an online Master's program that serves students nationally and internationally. It examines the critical components in the design and implementation of distance education, including…

  16. PERBANDINGAN EUCLIDEAN DISTANCE DENGAN CANBERRA DISTANCE PADA FACE RECOGNITION

    Directory of Open Access Journals (Sweden)

    Sendhy Rachmat Wurdianarto

    2014-08-01

    Full Text Available Perkembangan ilmu pada dunia komputer sangatlah pesat. Salah satu yang menandai hal ini adalah ilmu komputer telah merambah pada dunia biometrik. Arti biometrik sendiri adalah karakter-karakter manusia yang dapat digunakan untuk membedakan antara orang yang satu dengan yang lainnya. Salah satu pemanfaatan karakter / organ tubuh pada setiap manusia yang digunakan untuk identifikasi (pengenalan adalah dengan memanfaatkan wajah. Dari permasalahan diatas dalam pengenalan lebih tentang aplikasi Matlab pada Face Recognation menggunakan metode Euclidean Distance dan Canberra Distance. Model pengembangan aplikasi yang digunakan adalah model waterfall. Model waterfall beriisi rangkaian aktivitas proses yang disajikan dalam proses analisa kebutuhan, desain menggunakan UML (Unified Modeling Language, inputan objek gambar diproses menggunakan Euclidean Distance dan Canberra Distance. Kesimpulan yang dapat ditarik adalah aplikasi face Recognation menggunakan metode euclidean Distance dan Canverra Distance terdapat kelebihan dan kekurangan masing-masing. Untuk kedepannya aplikasi tersebut dapat dikembangkan dengan menggunakan objek berupa video ataupun objek lainnya.   Kata kunci : Euclidean Distance, Face Recognition, Biometrik, Canberra Distance

  17. Fostering cooperative activism through critical design

    DEFF Research Database (Denmark)

    Menendez Blanco, Maria; Bjørn, Pernille; De Angeli, Antonella

    2017-01-01

    Critical design is gaining momentum in interaction design, yet little CSCW research has focused on articulating the cooperative potentials of critical design artefacts. We address this gap by reflecting upon a design project aimed at overturning the prevailing narrative regarding dyslexia in Italy....... The adversarial propositions embedded in our critical design artefacts challenged the description of dyslexia as a learning disorder putting forward the view of a learning difference. These artefacts demonstrated their capacity to bridge heterogeneous social worlds (those of teachers, children, and parents......) into one cooperative entity and mobilise cooperative activism. The contribution to CSCW is two-fold. Firstly, we introduce the cooperative potentials of critical design artefacts; secondly, we propose critical design as a strategy for researchers engaging with cooperative activism....

  18. GapBlaster-A Graphical Gap Filler for Prokaryote Genomes.

    Directory of Open Access Journals (Sweden)

    Pablo H C G de Sá

    Full Text Available The advent of NGS (Next Generation Sequencing technologies has resulted in an exponential increase in the number of complete genomes available in biological databases. This advance has allowed the development of several computational tools enabling analyses of large amounts of data in each of the various steps, from processing and quality filtering to gap filling and manual curation. The tools developed for gap closure are very useful as they result in more complete genomes, which will influence downstream analyses of genomic plasticity and comparative genomics. However, the gap filling step remains a challenge for genome assembly, often requiring manual intervention. Here, we present GapBlaster, a graphical application to evaluate and close gaps. GapBlaster was developed via Java programming language. The software uses contigs obtained in the assembly of the genome to perform an alignment against a draft of the genome/scaffold, using BLAST or Mummer to close gaps. Then, all identified alignments of contigs that extend through the gaps in the draft sequence are presented to the user for further evaluation via the GapBlaster graphical interface. GapBlaster presents significant results compared to other similar software and has the advantage of offering a graphical interface for manual curation of the gaps. GapBlaster program, the user guide and the test datasets are freely available at https://sourceforge.net/projects/gapblaster2015/. It requires Sun JDK 8 and Blast or Mummer.

  19. Cultural Distance Revisited: Towards a More Rigorous Conceptualization and Measurement of Cultural Differences

    OpenAIRE

    Oded Shenkar

    2001-01-01

    Cultural distance is a widely used construct in international business, where it has been applied to foreign investment expansion, entry mode choice, and the performance of foreign invested affiliates, among others. The present paper presents a critical review of the cultural distance construct, outlining its hidden assumptions and challenging its theoretical and methodological properties. A comprehensive framework for the treatment of the construct is developed and concrete steps aimed at en...

  20. Distance Education Programs: The Technical Support to Be Successful.

    Science.gov (United States)

    McNew, Ryan E; Gordon, Jeffry S; Weiner, Elizabeth E; Trangenstein, Patricia

    2016-01-01

    Academic success requires support on a variety of levels as well as access to contemporary tools and services. Supporting students enrolled in a successful higher education distance learning program, requires a strong, properly trained IT support staff in addition to a stable IT environment. Our distance education program began with a regional market but has grown significantly over the past few years. This is primarily due to the success of our distance education tools and support which have contributed to achieving a ranking of eleventh of best graduate schools in nursing according to the U.S. News and World Report. The entire student population is "Bring Your Own Devices" (BYOD). Critical to this support is the initial configuration and loading of needed software during the first week of orientation. All of this success requires a robust team of members prepared in a range of skill sets from networking to instructional design.

  1. The effect of intertextuality on Iranian EFL learners’ critical writing

    Directory of Open Access Journals (Sweden)

    Saeideh Ahangari

    2014-01-01

    Full Text Available Intertextuality is the relation of each text with the texts surrounding it. Any word or phrase we are writing or saying has relationship with what we have heard or seen before. This shared language makes others understand us. On the other hand, critical thinking is the ability to think reasonably, reflectively and skillfully. Since it is believed that intertextuality results in critical thinking, this study aimed to focus on the effect of intertextuality on learners’ critical writing skill. To do so, the researchers selected 60 Advanced EFL students from three intact classes at the Iran Language Institute and assigned them randomly into three groups. After assuring the groups’ homogeneity in terms of their general English proficiency and writing skill in the beginning of the study, the researchers asked the first group, considered as the control group, to write a composition about Generation Gap. Then the first experimental group read two texts about Generation Gap and then wrote a composition about it; the second experimental group watched a short film about Generation Gap besides reading the texts and then wrote a composition about it. Having compared the written compositions in terms of critical thinking elements, the researchers found out that there is a meaningful relationship between intertextuality and critical writing. That is to say, the more intertextual relationship (in our case print and visual texts the learners are involved with, the more critical elements they utilize in their writing. Findings of this research have some pedagogical implications.

  2. On the sub-band gap optical absorption in heat treated cadmium sulphide thin film deposited on glass by chemical bath deposition technique

    International Nuclear Information System (INIS)

    Chattopadhyay, P.; Karim, B.; Guha Roy, S.

    2013-01-01

    The sub-band gap optical absorption in chemical bath deposited cadmium sulphide thin films annealed at different temperatures has been critically analyzed with special reference to Urbach relation. It has been found that the absorption co-efficient of the material in the sub-band gap region is nearly constant up to a certain critical value of the photon energy. However, as the photon energy exceeds the critical value, the absorption coefficient increases exponentially indicating the dominance of Urbach rule. The absorption coefficients in the constant absorption region and the Urbach region have been found to be sensitive to annealing temperature. A critical examination of the temperature dependence of the absorption coefficient indicates two different kinds of optical transitions to be operative in the sub-band gap region. After a careful analyses of SEM images, energy dispersive x-ray spectra, and the dc current-voltage characteristics, we conclude that the absorption spectra in the sub-band gap domain is possibly associated with optical transition processes involving deep levels and the grain boundary states of the material

  3. On the sub-band gap optical absorption in heat treated cadmium sulphide thin film deposited on glass by chemical bath deposition technique

    Science.gov (United States)

    Chattopadhyay, P.; Karim, B.; Guha Roy, S.

    2013-12-01

    The sub-band gap optical absorption in chemical bath deposited cadmium sulphide thin films annealed at different temperatures has been critically analyzed with special reference to Urbach relation. It has been found that the absorption co-efficient of the material in the sub-band gap region is nearly constant up to a certain critical value of the photon energy. However, as the photon energy exceeds the critical value, the absorption coefficient increases exponentially indicating the dominance of Urbach rule. The absorption coefficients in the constant absorption region and the Urbach region have been found to be sensitive to annealing temperature. A critical examination of the temperature dependence of the absorption coefficient indicates two different kinds of optical transitions to be operative in the sub-band gap region. After a careful analyses of SEM images, energy dispersive x-ray spectra, and the dc current-voltage characteristics, we conclude that the absorption spectra in the sub-band gap domain is possibly associated with optical transition processes involving deep levels and the grain boundary states of the material.

  4. A distance constrained synaptic plasticity model of C. elegans neuronal network

    Science.gov (United States)

    Badhwar, Rahul; Bagler, Ganesh

    2017-03-01

    Brain research has been driven by enquiry for principles of brain structure organization and its control mechanisms. The neuronal wiring map of C. elegans, the only complete connectome available till date, presents an incredible opportunity to learn basic governing principles that drive structure and function of its neuronal architecture. Despite its apparently simple nervous system, C. elegans is known to possess complex functions. The nervous system forms an important underlying framework which specifies phenotypic features associated to sensation, movement, conditioning and memory. In this study, with the help of graph theoretical models, we investigated the C. elegans neuronal network to identify network features that are critical for its control. The 'driver neurons' are associated with important biological functions such as reproduction, signalling processes and anatomical structural development. We created 1D and 2D network models of C. elegans neuronal system to probe the role of features that confer controllability and small world nature. The simple 1D ring model is critically poised for the number of feed forward motifs, neuronal clustering and characteristic path-length in response to synaptic rewiring, indicating optimal rewiring. Using empirically observed distance constraint in the neuronal network as a guiding principle, we created a distance constrained synaptic plasticity model that simultaneously explains small world nature, saturation of feed forward motifs as well as observed number of driver neurons. The distance constrained model suggests optimum long distance synaptic connections as a key feature specifying control of the network.

  5. Encyclopedia of distances

    CERN Document Server

    Deza, Michel Marie

    2016-01-01

    This 4th edition of the leading reference volume on distance metrics is characterized by updated and rewritten sections on some items suggested by experts and readers, as well a general streamlining of content and the addition of essential new topics. Though the structure remains unchanged, the new edition also explores recent advances in the use of distances and metrics for e.g. generalized distances, probability theory, graph theory, coding theory, data analysis. New topics in the purely mathematical sections include e.g. the Vitanyi multiset-metric, algebraic point-conic distance, triangular ratio metric, Rossi-Hamming metric, Taneja distance, spectral semimetric between graphs, channel metrization, and Maryland bridge distance. The multidisciplinary sections have also been supplemented with new topics, including: dynamic time wrapping distance, memory distance, allometry, atmospheric depth, elliptic orbit distance, VLBI distance measurements, the astronomical system of units, and walkability distance. Lea...

  6. Gap junctions mediate large-scale Turing structures in a mean-field cortex driven by subcortical noise

    Science.gov (United States)

    Steyn-Ross, Moira L.; Steyn-Ross, D. A.; Wilson, M. T.; Sleigh, J. W.

    2007-07-01

    One of the grand puzzles in neuroscience is establishing the link between cognition and the disparate patterns of spontaneous and task-induced brain activity that can be measured clinically using a wide range of detection modalities such as scalp electrodes and imaging tomography. High-level brain function is not a single-neuron property, yet emerges as a cooperative phenomenon of multiply-interacting populations of neurons. Therefore a fruitful modeling approach is to picture the cerebral cortex as a continuum characterized by parameters that have been averaged over a small volume of cortical tissue. Such mean-field cortical models have been used to investigate gross patterns of brain behavior such as anesthesia, the cycles of natural sleep, memory and erasure in slow-wave sleep, and epilepsy. There is persuasive and accumulating evidence that direct gap-junction connections between inhibitory neurons promote synchronous oscillatory behavior both locally and across distances of some centimeters, but, to date, continuum models have ignored gap-junction connectivity. In this paper we employ simple mean-field arguments to derive an expression for D2 , the diffusive coupling strength arising from gap-junction connections between inhibitory neurons. Using recent neurophysiological measurements reported by Fukuda [J. Neurosci. 26, 3434 (2006)], we estimate an upper limit of D2≈0.6cm2 . We apply a linear stability analysis to a standard mean-field cortical model, augmented with gap-junction diffusion, and find this value for the diffusive coupling strength to be close to the critical value required to destabilize the homogeneous steady state. Computer simulations demonstrate that larger values of D2 cause the noise-driven model cortex to spontaneously crystalize into random mazelike Turing structures: centimeter-scale spatial patterns in which regions of high-firing activity are intermixed with regions of low-firing activity. These structures are consistent with the

  7. Experiments investigating the effects of the accelerating gap voltage pulse on the ion focused (IFR) high current electron recirculators

    International Nuclear Information System (INIS)

    Mazarakis, M.G.; Smith, D.L.; Poukey, J.W.; Wagner, J.S.; Bennett, L.F.; Olson, W.R.; Turman, B.N.; Prestwich, K.R.; Wells, J.

    1991-01-01

    The lifetime of the Ion Focusing Regime (IFR) channel following the pulsing of the post-accelerating gaps is critical for an open-ended, spiral recirculating electron linear accelerator. It dictates the number of allowable beam recirculations through the gap. In the case of a racetrack configuration, it is significant but not as critical, since the presence of the electron beam focuses the ions and lengthens the lifetime of the ion channel. It was established that pulsing the accelerating gap perturbs the IFR channel. However, for the parameters studied, the lifetime is long enough to allow at least four beam recirculations in a spiral device. In addition, cusp fields positioned upstream and downstream from the gap prevent it from perturbing the IFR channel. 4 refs., 5 figs., 1 tab

  8. Distance Learning

    National Research Council Canada - National Science Library

    Braddock, Joseph

    1997-01-01

    A study reviewing the existing Army Distance Learning Plan (ADLP) and current Distance Learning practices, with a focus on the Army's training and educational challenges and the benefits of applying Distance Learning techniques...

  9. Conceptualizing the cross-cultural gaps in managing international aid: HIV/AIDS and TB project delivery in Southern Africa.

    Science.gov (United States)

    Jackson, Terence

    2011-01-01

    There appears to be a gap between the billions of dollars inputted into fighting HIV/AIDS and TB and outcomes. This in part can be attributed to the lack of attention in International Development to managing programmes and projects within complex levels of cross-cultural interactions. International Development often ignores management issues, yet Management Studies is left wanting through a lack of engagement with development issues including the fight against disease and poverty. This paper attempts to link these two disciplines towards mutual benefit, through a critical cross-cultural approach. It provides contextualization of international development policies/strategies; conceptualization of dominant paradigms; structural analysis of how a programme/project fits into the global governance structure; analysis of complexities and levels of cross-cultural interaction and their consequences and the process and implications of knowledge transfer across cultural distances. It concludes with implications for policy and practice, as well as what is needed from cross-disciplinary research. This includes how feedback loops can be strengthened from local to global, how indigenous knowledge may be better understood and integrated, how power relations within the global governance structure could be managed, how cross-cultural interaction could be better understood, and how knowledge transfer/sharing should be critically managed. Copyright © 2010 John Wiley & Sons, Ltd.

  10. Critical factors for EIA implementation

    DEFF Research Database (Denmark)

    Zhang, Jasmine; Kørnøv, Lone; Christensen, Per

    2013-01-01

    After decades of development, the gap between expectations of Environment Impact Assessments (EIA) and their practical performance remains significant. Research has been done to identify the critical factors for an effective implementation of EIA. However, this research, to a large extent, has...... not been cumulated and analysed comprehensively according to the stages of the EIA process. This paper contributes to the critical review of the literature on EIA implementation and effectiveness by cumulating mainly empirical findings in an implementation theoretical perspective. It focuses on the links...... between different critical factors and how they relate to different stages in the EIA and thus influence the decision making process. After reviewing 33 refereed journal articles published between 1999 and 2011, we identified 203 notions of critical factors. Of these, 102 related to different stages...

  11. Experimental investigations of argon spark gap recovery times by developing a high voltage double pulse generator.

    Science.gov (United States)

    Reddy, C S; Patel, A S; Naresh, P; Sharma, Archana; Mittal, K C

    2014-06-01

    The voltage recovery in a spark gap for repetitive switching has been a long research interest. A two-pulse technique is used to determine the voltage recovery times of gas spark gap switch with argon gas. First pulse is applied to the spark gap to over-volt the gap and initiate the breakdown and second pulse is used to determine the recovery voltage of the gap. A pulse transformer based double pulse generator capable of generating 40 kV peak pulses with rise time of 300 ns and 1.5 μs FWHM and with a delay of 10 μs-1 s was developed. A matrix transformer topology is used to get fast rise times by reducing L(l)C(d) product in the circuit. Recovery Experiments have been conducted for 2 mm, 3 mm, and 4 mm gap length with 0-2 bars pressure for argon gas. Electrodes of a sparkgap chamber are of rogowsky profile type, made up of stainless steel material, and thickness of 15 mm are used in the recovery study. The variation in the distance and pressure effects the recovery rate of the spark gap. An intermediate plateu is observed in the spark gap recovery curves. Recovery time decreases with increase in pressure and shorter gaps in length are recovering faster than longer gaps.

  12. The effects of gaseous bubble composition and gap distance on the characteristics of nanosecond discharges in distilled water

    KAUST Repository

    Hamdan, Ahmad; Cha, Min

    2016-01-01

    of the plasma by time-resolved imaging to find that increasing the size of the gap reduces the injected charges. Moreover, we determine the plasma characteristics, including electron density, excitation temperatures (for atoms and ions), and rotational

  13. Criticality in Location-Based Management of Construction

    DEFF Research Database (Denmark)

    Büchmann-Slorup, Rolf

    , the current literature does not include a collected description of what constitute critical activities in LBM. Nor have the implications for scheduling and control efforts of these changes in criticality been described. Accordingly, the present thesis establishes a collected criticality principle of LBM......; highlights the implications of this alternative criticality principle to the schedule and control effort on construction projects; and suggests how time buffers should be applied on LBM projects to protect critical activities, compress project’s lead times, optimize flow, and minimize resource consumption....... The thesis offers three main results that contribute to the current LBM literature and close some of the gaps therein. The thesis conceptualizes the criticality principle of LBM by analyzing the relationship between inherent constraints in LBM and the lead times of projects. The collected criticality...

  14. Tuning the band gap in hybrid tin iodide perovskite semiconductors using structural templating.

    Science.gov (United States)

    Knutson, Jeremy L; Martin, James D; Mitzi, David B

    2005-06-27

    Structural distortions within the extensive family of organic/inorganic hybrid tin iodide perovskite semiconductors are correlated with their experimental exciton energies and calculated band gaps. The extent of the in- and out-of-plane angular distortion of the SnI4(2-) perovskite sheets is largely determined by the relative charge density and steric requirements of the organic cations. Variation of the in-plane Sn-I-Sn bond angle was demonstrated to have the greatest impact on the tuning of the band gap, and the equatorial Sn-I bond distances have a significant secondary influence. Extended Hückel tight-binding band calculations are employed to decipher the crystal orbital origins of the structural effects that fine-tune the band structure. The calculations suggest that it may be possible to tune the band gap by as much as 1 eV using the templating influence of the organic cation.

  15. Millimeter-Gap Magnetically Insulated Transmission Line Power Flow Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Hutsel, Brian Thomas [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Stoltzfus, Brian S. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Fowler, William E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); LeChien, Keith R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Mazarakis, Michael G. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Moore, James K. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Mulville, Thomas D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Savage, Mark E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Stygar, William A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); McKenney, John L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Jones, Peter A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); MacRunnels, Diego J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Long, Finis W. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Porter, John L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-09-01

    An experiment platform has been designed to study vacuum power flow in magnetically insulated transmission lines (MITLs). The platform was driven by the 400-GW Mykonos-V accelerator. The experiments conducted quantify the current loss in a millimeter-gap MITL with respect to vacuum conditions in the MITL for two different gap distances, 1.0 and 1.3 mm. The current loss for each gap was measured for three different vacuum pump down times. As a ride along experiment, multiple shots were conducted with each set of hardware to determine if there was a conditioning effect to increase current delivery on subsequent shots. The experiment results revealed large differences in performance for the 1.0 and 1.3 mm gaps. The 1.0 mm gap resulted in current loss of 40%-60% of peak current. The 1.3 mm gap resulted in current losses of less than 5% of peak current. Classical MITL models that neglect plasma expansion predict that there should be zero current loss, after magnetic insulation is established, for both of these gaps. The experiments result s indicate that the vacuum pressure or pump down time did not have a significant effect on the measured current loss at vacuum pressures between 1e-4 and 1e-5 Torr. Additionally, there was not repeatable evidence of a conditioning effect that reduced current loss for subsequent full-energy shots on a given set of hardware. It should be noted that the experiments conducted likely did not have large loss contributions due to ion emission from the anode due to the relatively small current densi-ties (25-40 kA/cm) in the MITL that limited the anode temperature rise due to ohmic heating. The results and conclusions from these experiments may have limited applicability to MITLs of high current density (>400 kA/cm) used in the convolute and load region of the Z which experience temperature increases of >400° C and generate ion emission from anode surfaces.

  16. A Critical Review of Instructional Design Process of Distance Learning System

    Science.gov (United States)

    Chaudry, Muhammad Ajmal; ur-Rahman, Fazal

    2010-01-01

    Instructional design refers to planning, development, delivery and evaluation of instructional system. It is an applied field of study aiming at the application of descriptive research outcomes in regular instructional settings. The present study was designed to critically review the process of instructional design at Allama Iqbal Open University…

  17. REPRESENTATIONS OF DISTANCE: DIFFERENCES IN UNDERSTANDING DISTANCE ACCORDING TO TRAVEL METHOD

    Directory of Open Access Journals (Sweden)

    Gunvor Riber Larsen

    2017-12-01

    Full Text Available This paper explores how Danish tourists represent distance in relation to their holiday mobility and how these representations of distance are a result of being aero-mobile as opposed to being land-mobile. Based on interviews with Danish tourists, whose holiday mobility ranges from the European continent to global destinations, the first part of this qualitative study identifies three categories of representations of distance that show how distance is being ‘translated’ by the tourists into non-geometric forms: distance as resources, distance as accessibility, and distance as knowledge. The representations of distance articulated by the Danish tourists show that distance is often not viewed in ‘just’ kilometres. Rather, it is understood in forms that express how transcending the physical distance through holiday mobility is dependent on individual social and economic contexts, and on whether the journey was undertaken by air or land. The analysis also shows that being aeromobile is the holiday transportation mode that removes the tourists the furthest away from physical distance, resulting in the distance travelled by air being represented in ways that have the least correlation, in the tourists’ minds, with physical distance measured in kilometres.

  18. Understanding the current status and exploring the potential for distance education in public health in India.

    Science.gov (United States)

    Sharma, Kavya; George, Sunil; Zodpey, Sanjay

    2011-01-01

    Continuing education of health care providers plays an important role in producing a health work force that is efficient and effective. In India public health education has primarily relied on conventional methods of training. However, such methods have limitations in equipping the health workforce of a vast and varied country like India. This paper analyzes the current status of distance education in public health and lists the various courses that are presently available in India through the distance education mode. Presently 25 institutions in India are offering 69 courses in various domains of public health through distance education. The providers of these programs comprised both government and private educational institutions. This paper also points out the role and importance of various stakeholders in the design and delivery of distance education programs in public health and raises key areas that need attention in the governance of such programs. It urges the use of digital technology in the delivery of distance education programs and points out how distance education that is designed and delivered using the latest technology could address the current gap in training human resources for health in India.

  19. An adaptive distance measure for use with nonparametric models

    International Nuclear Information System (INIS)

    Garvey, D. R.; Hines, J. W.

    2006-01-01

    Distance measures perform a critical task in nonparametric, locally weighted regression. Locally weighted regression (LWR) models are a form of 'lazy learning' which construct a local model 'on the fly' by comparing a query vector to historical, exemplar vectors according to a three step process. First, the distance of the query vector to each of the exemplar vectors is calculated. Next, these distances are passed to a kernel function, which converts the distances to similarities or weights. Finally, the model output or response is calculated by performing locally weighted polynomial regression. To date, traditional distance measures, such as the Euclidean, weighted Euclidean, and L1-norm have been used as the first step in the prediction process. Since these measures do not take into consideration sensor failures and drift, they are inherently ill-suited for application to 'real world' systems. This paper describes one such LWR model, namely auto associative kernel regression (AAKR), and describes a new, Adaptive Euclidean distance measure that can be used to dynamically compensate for faulty sensor inputs. In this new distance measure, the query observations that lie outside of the training range (i.e. outside the minimum and maximum input exemplars) are dropped from the distance calculation. This allows for the distance calculation to be robust to sensor drifts and failures, in addition to providing a method for managing inputs that exceed the training range. In this paper, AAKR models using the standard and Adaptive Euclidean distance are developed and compared for the pressure system of an operating nuclear power plant. It is shown that using the standard Euclidean distance for data with failed inputs, significant errors in the AAKR predictions can result. By using the Adaptive Euclidean distance it is shown that high fidelity predictions are possible, in spite of the input failure. In fact, it is shown that with the Adaptive Euclidean distance prediction

  20. Psychological distance of pedestrian at the bus terminal area

    Science.gov (United States)

    Firdaus Mohamad Ali, Mohd; Salleh Abustan, Muhamad; Hidayah Abu Talib, Siti; Abustan, Ismail; Rahman, Noorhazlinda Abd; Gotoh, Hitoshi

    2018-03-01

    Walking is a part of transportation modes that is effective for pedestrian in either short or long trips. All people are classified as pedestrian because people do walk every day and the higher number of people walking will lead to crowd conditions and that is the reason of the importance to study about the behaviour of pedestrian specifically the psychological distance in both indoor and outdoor. Nowadays, the number of studies of crowd dynamics among pedestrian have increased due to the concern about the safety issues primarily related to the emergency cases such as fire, earthquake, festival and etc. An observation of pedestrian was conducted at one of the main bus terminals in Kuala Lumpur with the main objective to obtain pedestrian psychological distance and it took place for 45 minutes by using a camcorder that was set up by using a tripod on the upper floor from the area of observation at the main lobby and the trapped area was approximately 100 m2. The analysis was focused on obtaining the gap between pedestrian based on two different categories, which are; (a) Pedestrian with relationship, and (b) Pedestrian without relationship. In total, 1,766 data were obtained during the analysis in which 561 data were obtained for `Pedestrian with relationship' and 1,205 data were obtained for "Pedestrian without relationship". Based on the obtained results, "Pedestrian without relationship" had shown a slightly higher average value of psychological distance between them compare to "Pedestrian with relationship" with the results of 1.6360m and 1.5909m respectively. In gender case, "Pedestrian without relationship" had higher mean of psychological distance in all three categories as well. Therefore, it can be concluded that pedestrian without relationship tend to have longer distance when walking in crowds.

  1. More rapid climate change promotes evolutionary rescue through selection for increased dispersal distance.

    Science.gov (United States)

    Boeye, Jeroen; Travis, Justin M J; Stoks, Robby; Bonte, Dries

    2013-02-01

    Species can either adapt to new conditions induced by climate change or shift their range in an attempt to track optimal environmental conditions. During current range shifts, species are simultaneously confronted with a second major anthropogenic disturbance, landscape fragmentation. Using individual-based models with a shifting climate window, we examine the effect of different rates of climate change on the evolution of dispersal distances through changes in the genetically determined dispersal kernel. Our results demonstrate that the rate of climate change is positively correlated to the evolved dispersal distances although too fast climate change causes the population to crash. When faced with realistic rates of climate change, greater dispersal distances evolve than those required for the population to keep track of the climate, thereby maximizing population size. Importantly, the greater dispersal distances that evolve when climate change is more rapid, induce evolutionary rescue by facilitating the population in crossing large gaps in the landscape. This could ensure population persistence in case of range shifting in fragmented landscapes. Furthermore, we highlight problems in using invasion speed as a proxy for potential range shifting abilities under climate change.

  2. A classical treatment of optical tunneling in plasmonic gaps: extending the quantum corrected model to practical situations

    DEFF Research Database (Denmark)

    Esteban, Rubén; Zugarramurdi, Asier; Zhang, Pu

    2015-01-01

    The optical response of plasmonic nanogaps is challenging to address when the separation between the two nanoparticles forming the gap is reduced to a few nanometers or even subnanometer distances. We have compared results of the plasmon response within different levels of approximation, and iden...

  3. Difficult relationships: critical pedagogies and curriculum

    OpenAIRE

    María Verónica Di Caudo Villoslada

    2013-01-01

    This paper reviews the proposals of the ‘critical pedagogies’ and presents some difficulties in the realization of their principles in the context of current public policies in Latin America. Distances between discourses and practices, absence of radically democratic educational policies, lack of awareness of critical pedagogies by teachers, lack of contextual production and indiscriminate use of the word critical—that ends up opposing everything that is considered as traditional pedagogy—mak...

  4. Think Like a Nurse: A Critical Thinking Initiative.

    Science.gov (United States)

    Ward, Terry D; Morris, Tiffany

    2016-01-01

    Critical thinking is essential in the practice of the nurse generalist, today. Nursing faculty is frequently trying to identify teaching strategies in promoting critical thinking and engaging students in active learning. To close the gap between critical thinking and student success, a school in the south east United States implemented the use of the 'think like a nurse initiative" for incoming junior nursing students. Faculty collaborated to adopt the fundamental and essential nursing concepts for nursing students to support thinking like a nurse.

  5. Automated inspection of gaps on the free-form shape parts by laser scanning technologies

    Science.gov (United States)

    Zhou, Sen; Xu, Jian; Tao, Lei; An, Lu; Yu, Yan

    2018-01-01

    In industrial manufacturing processes, the dimensional inspection of the gaps on the free-form shape parts is critical and challenging, and is directly associated with subsequent assembly and terminal product quality. In this paper, a fast measuring method for automated gap inspection based on laser scanning technologies is presented. The proposed measuring method consists of three steps: firstly, the relative position is determined according to the geometric feature of measuring gap, which considers constraints existing in a laser scanning operation. Secondly, in order to acquire a complete gap profile, a fast and effective scanning path is designed. Finally, the range dimension of the gaps on the free-form shape parts including width, depth and flush, correspondingly, is described in a virtual environment. In the future, an appliance machine based on the proposed method will be developed for the on-line dimensional inspection of gaps on the automobile or aerospace production line.

  6. The F-BAR domains from srGAP1, srGAP2 and srGAP3 regulate membrane deformation differently

    Science.gov (United States)

    Coutinho-Budd, Jaeda; Ghukasyan, Vladimir; Zylka, Mark J.; Polleux, Franck

    2012-01-01

    Summary Coordination of membrane deformation and cytoskeletal dynamics lies at the heart of many biological processes critical for cell polarity, motility and morphogenesis. We have recently shown that Slit-Robo GTPase-activating protein 2 (srGAP2) regulates neuronal morphogenesis through the ability of its F-BAR domain to regulate membrane deformation and induce filopodia formation. Here, we demonstrate that the F-BAR domains of two closely related family members, srGAP1 and srGAP3 [designated F-BAR(1) and F-BAR(3), respectively] display significantly different membrane deformation properties in non-neuronal COS7 cells and in cortical neurons. F-BAR(3) induces filopodia in both cell types, though less potently than F-BAR(2), whereas F-BAR(1) prevents filopodia formation in cortical neurons and reduces plasma membrane dynamics. These three F-BAR domains can heterodimerize, and they act synergistically towards filopodia induction in COS7 cells. As measured by fluorescence recovery after photobleaching, F-BAR(2) displays faster molecular dynamics than F-BAR(3) and F-BAR(1) at the plasma membrane, which correlates well with its increased potency to induce filopodia. We also show that the molecular dynamic properties of F-BAR(2) at the membrane are partially dependent on F-Actin. Interestingly, acute phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5)P2] depletion in cells does not interfere with plasma membrane localization of F-BAR(2), which is compatible with our result showing that F-BAR(2) binds to a broad range of negatively-charged phospholipids present at the plasma membrane, including phosphatidylserine (PtdSer). Overall, our results provide novel insights into the functional diversity of the membrane deformation properties of this subclass of F-BAR-domains required for cell morphogenesis. PMID:22467852

  7. Specific heat of FeSe: Two gaps with different anisotropy in superconducting state

    Science.gov (United States)

    Muratov, A. V.; Sadakov, A. V.; Gavrilkin, S. Yu.; Prishchepa, A. R.; Epifanova, G. S.; Chareev, D. A.; Pudalov, V. M.

    2018-05-01

    We present detailed study of specific heat of FeSe single crystals with critical temperature Tc = 8.45 K at 0.4 - 200 K in magnetic fields 0 - 9 T. Analysis of the electronic specific heat at low temperatures shows the coexistence of isotropic s-wave gap and strongly anisotropic extended s-wave gap without nodes. It was found two possibilities of superconducting gap parameters which give equally description of experimental data: (i) two gaps with approximately equal amplitudes and weight contribution to specific heat: isotropic Δ1 = 1.7 meV (2Δ1 /kBTc =4.7) and anisotropic gap with the amplitude Δ2max = 1.8 meV (2 Δ2max /kBTc =4.9 and anisotropy parameter m = 0.85); (ii) two gaps with substantially different values: isotropic large gap Δ1 = 1.65 meV (2Δ1 /kBTc = 4.52) and anisotropic small gap Δ2max = 0.75 meV (2Δ2max /kBTc = 2) with anisotropy parameter m = 0.71 . These results are confirmed by the field behavior of the residual electronic specific heat γr.

  8. The Role of Work Function and Band Gap in Resistive Switching Behaviour of ZnTe Thin Films

    Science.gov (United States)

    Rowtu, Srinu; Sangani, L. D. Varma; Krishna, M. Ghanashyam

    2018-02-01

    Resistive switching behavior by engineering the electrode work function and band gap of ZnTe thin films is demonstrated. The device structures Au/ZnTe/Au, Au/ZnTe/Ag, Al/ZnTe/Ag and Pt/ZnTe/Ag were fabricated. ZnTe was deposited by thermal evaporation and the stoichiometry and band gap were controlled by varying the source-substrate distance. Band gap could be varied between 1.0 eV to approximately 4.0 eV with the larger band gap being attributed to the partial oxidation of ZnTe. The transport characteristics reveal that the low-resistance state is ohmic in nature which makes a transition to Poole-Frenkel defect-mediated conductivity in the high-resistance states. The highest R off-to- R on ratio achieved is 109. Interestingly, depending on stoichiometry, both unipolar and bipolar switching can be realized.

  9. From the Milky Way to differing galaxy environments: filling critical gaps in our knowledge of star formation and its interplay with dust, and in stellar and galaxy evolution.

    Science.gov (United States)

    Bianchi, Luciana

    2018-01-01

    Rest-frame UV, uniquely sensitive to luminous, short-lived hot massive stars, trace and age-date star formation across galaxies, and is very sensitive to dust, whose properties and presence are closely connected to star formation.With wide f-o-v and deep sensitivity in two broad filters,FUV and NUV,GALEX delivered the first comprehensive UV view of large nearby galaxies, and of the universe to z~2 (e.g.,Bianchi 2014 ApSS 354,103), detected star formation at the lowest rates, in environments where it was not seen before and not expected (e.g. Bianchi 2011 ApSS 335,51; Thilker+2009 Nature 457,990;2007 ApJS 173,538), triggering a new era of investigations with HST and large ground-based telescopes. New instrument technology and modeling capabilities make it now possible and compelling to solve standing issues. The scant UV filters available (esp. FUV) and the wide gap in resolution and f-o-v between GALEX and HST leaves old and new questions open. A chief limitation is degeneracies between physical parameters of stellar populations (age/SFR) and hot stars, and dust (e.g. Bianchi+ 2014 JASR 53,928).We show sample model simulations for filter optimization to provide critical measurements for the science objectives. We also demonstrate how adequate FUV+NUV filters, and resolution, allow us to move from speculative interpretation of UV data to unbiased physical characterization of young stellar populations and dust, using new data from UVIT, which, though smaller than CETUS, has better resolution and filter coverage than GALEX.Also, our understanding of galaxy chemical enrichment is limited by critical gaps in stellar evolution; GALEX surveys enabled the first unbiased census of the Milky Way hot-WD population (Bianchi+2011 MNRAS, 411,2770), which we complement with SDSS, Pan-STARRS, and Gaia data to fill such gaps (Bianchi et al.2018, ApSS). Such objects in CETUS fields (deeper exposures, more filters, and the first UV MOS) will be much better characterized, enabling

  10. Angle-resolved photoemission studies of the superconducting gap symmetry in Fe-based superconductors

    Directory of Open Access Journals (Sweden)

    Y.-B. Huang

    2012-12-01

    Full Text Available The superconducting gap is the fundamental parameter that characterizes the superconducting state, and its symmetry is a direct consequence of the mechanism responsible for Cooper pairing. Here we discuss about angle-resolved photoemission spectroscopy measurements of the superconducting gap in the Fe-based high-temperature superconductors. We show that the superconducting gap is Fermi surface dependent and nodeless with small anisotropy, or more precisely, a function of the momentum location in the Brillouin zone. We show that while this observation seems inconsistent with weak coupling approaches for superconductivity in these materials, it is well supported by strong coupling models and global superconducting gaps. We also suggest that a smaller lifetime of the superconducting Cooper pairs induced by the momentum dependent interband scattering inherent to these materials could affect the residual density of states at low energies, which is critical for a proper evaluation of the superconducting gap.

  11. Encyclopedia of distances

    CERN Document Server

    Deza, Michel Marie

    2014-01-01

    This updated and revised third edition of the leading reference volume on distance metrics includes new items from very active research areas in the use of distances and metrics such as geometry, graph theory, probability theory and analysis. Among the new topics included are, for example, polyhedral metric space, nearness matrix problems, distances between belief assignments, distance-related animal settings, diamond-cutting distances, natural units of length, Heidegger’s de-severance distance, and brain distances. The publication of this volume coincides with intensifying research efforts into metric spaces and especially distance design for applications. Accurate metrics have become a crucial goal in computational biology, image analysis, speech recognition and information retrieval. Leaving aside the practical questions that arise during the selection of a ‘good’ distance function, this work focuses on providing the research community with an invaluable comprehensive listing of the main available di...

  12. Experimental demonstration of line-width modulation in plasmonic lithography using a solid immersion lens-based active nano-gap control

    International Nuclear Information System (INIS)

    Lee, Won-Sup; Kim, Taeseob; Choi, Guk-Jong; Lim, Geon; Joe, Hang-Eun; Gang, Myeong-Gu; Min, Byung-Kwon; Park, No-Cheol; Moon, Hyungbae; Kim, Do-Hyung; Park, Young-Pil

    2015-01-01

    Plasmonic lithography has been used in nanofabrication because of its utility beyond the diffraction limit. The resolution of plasmonic lithography depends on the nano-gap between the nanoaperture and the photoresist surface—changing the gap distance can modulate the line-width of the pattern. In this letter, we demonstrate solid-immersion lens based active non-contact plasmonic lithography, applying a range of gap conditions to modulate the line-width of the pattern. Using a solid-immersion lens-based near-field control system, the nano-gap between the exit surface of the nanoaperture and the media can be actively modulated and maintained to within a few nanometers. The line-widths of the recorded patterns using 15- and 5-nm gaps were 47 and 19.5 nm, respectively, which matched closely the calculated full-width at half-maximum. From these results, we conclude that changing the nano-gap within a solid-immersion lens-based plasmonic head results in varying line-width patterns

  13. ETHICAL PERSPECTIVES IN OPEN AND DISTANCE EDUATION SYSTEM

    Directory of Open Access Journals (Sweden)

    C. ANITHA (Corresponding Author,

    2013-01-01

    Full Text Available Today, e-learning and various online education applications are used in many countries and educational institutions than ever before. Ethics deals with the principle governing ideal or good behavior, it focuses on what is right or what is wrong. Although in education, the ethical issues that they may be facing are not about of life and death issues. An ethical dilemma will take place when the educator faced with a decision that maybe incongruent with the organization’s values and policies. There are several examples of ethical issues in education. In this reason, the educator must be guided with the appropriate decision-making strategies. With the increasing use of new communication technologies, adoption of distance education by traditional educational institutes and owing to growing demand on the part of learners, it becomes more important to discuss the ethical issues. This important title provides academicians, students, and professionals with ethical insight into the world of e-learning through fascinating case studies that elucidate the issues through real-world examples. Pioneer’s experience in the field of distance education indicates that the profile of distance learners varies, cutting across barriers of gender, class and caste. The distance learner may be suffering from a sense of isolation as he/she makes a return to study after a gap of time or while working. It is there that the distance educator makes a positive, ethical and interventionist role by helping the student to learn beyond the stereotypical classroom situation and can act effectively as the friend, philosopher and guide of the learner. However, the industry of education is a serious one, requiring well defined ethics and values, well bound in visible legal outlines to regulate its exchange and distribution. Because as the industry grows, so do the issues of ethical concern such as plagiarism, electronic voyeurism, and licensing. The objective of this paper is to

  14. Applying revised gap analysis model in measuring hotel service quality.

    Science.gov (United States)

    Lee, Yu-Cheng; Wang, Yu-Che; Chien, Chih-Hung; Wu, Chia-Huei; Lu, Shu-Chiung; Tsai, Sang-Bing; Dong, Weiwei

    2016-01-01

    With the number of tourists coming to Taiwan growing by 10-20 % since 2010, the number has increased due to an increasing number of foreign tourists, particularly after deregulation allowed admitting tourist groups, followed later on by foreign individual tourists, from mainland China. The purpose of this study is to propose a revised gap model to evaluate and improve service quality in Taiwanese hotel industry. Thus, service quality could be clearly measured through gap analysis, which was more effective for offering direction in developing and improving service quality. The HOLSERV instrument was used to identify and analyze service gaps from the perceptions of internal and external customers. The sample for this study included three main categories of respondents: tourists, employees, and managers. The results show that five gaps influenced tourists' evaluations of service quality. In particular, the study revealed that Gap 1 (management perceptions vs. customer expectations) and Gap 9 (service provider perceptions of management perceptions vs. service delivery) were more critical than the others in affecting perceived service quality, making service delivery the main area of improvement. This study contributes toward an evaluation of the service quality of the Taiwanese hotel industry from the perspectives of customers, service providers, and managers, which is considerably valuable for hotel managers. It was the aim of this study to explore all of these together in order to better understand the possible gaps in the hotel industry in Taiwan.

  15. A Correlational Study on Critical Thinking in Nursing as an Outcome Variable for Success

    Science.gov (United States)

    Porter, Rebecca Jean

    2018-01-01

    Critical thinking is a required curricular outcome for nursing education; however, the literature shows a gap related to valid and reliable tools to measure critical thinking specific to nursing and relating that critical thinking measurement to meaningful outcomes. This study examined critical thinking scores, as measured by Assessment…

  16. Do air-gaps behind soft body armour affect protection?

    Science.gov (United States)

    Tilsley, Lee; Carr, D J; Lankester, C; Malbon, C

    2018-02-01

    Body armour typically comprises a fabric garment covering the torso combined with hard armour (ceramic/composite). Some users wear only soft armour which provides protection from sharp weapons and pistol ammunition. It is usually recommended that body armour is worn against the body with no air-gaps being present between the wearer and the armour. However, air-gaps can occur in certain situations such as females around the breasts, in badly fitting armour and where manufacturers have incorporated an air-gap claiming improvements in thermophysiological burden. The effect of an air-gap on the ballistic protection and the back face signature (BFS) as a result of a non-perforating ballistic impact was determined. Armour panels representative of typical police armour (400x400 mm) were mounted on calibrated Roma Plastilina No 1 and impacted with 9 mm Luger FMJ (9×19 mm; full metal jacket; Dynamit Nobel DM11A1B2) ammunition at 365±10 m/s with a range of air-gaps (0-15 mm). Whether or not the ammunition perforated the armour was noted, the BFS was measured and the incidence of pencilling (a severe, deep and narrow BFS) was identified. For 0° impacts, a critical air-gap size of 10 mm is detrimental to armour performance for the armour/ammunition combination assessed in this work. Specifically, the incidences of pencilling were more common with a 10 mm air-gap and resulted in BFS depth:volume ratios ≥1.0. For impacts at 30° the armour was susceptible to perforation irrespective of air-gap. This work suggested that an air-gap behind police body armour might result in an increased likelihood of injury. It is recommended that body armour is worn with no air-gap underneath. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  17. Critical Literacy and Social Justice

    Science.gov (United States)

    Comber, Barbara

    2015-01-01

    Given the global escalation of gaps between rich and poor, contemporary work in critical literacy needs to overtly question the politics of poverty. How and where is poverty produced, by what means, by whom and for whom and how are educational systems stratified to provide different kinds of education to the rich and the poor? Yet rather than…

  18. Interface Simulation Distances

    Directory of Open Access Journals (Sweden)

    Pavol Černý

    2012-10-01

    Full Text Available The classical (boolean notion of refinement for behavioral interfaces of system components is the alternating refinement preorder. In this paper, we define a distance for interfaces, called interface simulation distance. It makes the alternating refinement preorder quantitative by, intuitively, tolerating errors (while counting them in the alternating simulation game. We show that the interface simulation distance satisfies the triangle inequality, that the distance between two interfaces does not increase under parallel composition with a third interface, and that the distance between two interfaces can be bounded from above and below by distances between abstractions of the two interfaces. We illustrate the framework, and the properties of the distances under composition of interfaces, with two case studies.

  19. Phase diagram, correlation gap, and critical properties of the Coulomb glass

    Science.gov (United States)

    Palassini, Matteo; Goethe, Martin

    2009-03-01

    We investigate the lattice Coulomb glass model in three dimensions via extensive Monte Carlo simulations. 1. No evidence for an equilibrium glass phase is found down to very low temperatures, contrary to mean-field predictions, although the correlation length increases rapidly near T=0. 2. The single-particle density of states near the Coulomb gap satisfies the scaling law g(e,T)=T^λf(e/T) with λ 2.2. 3. A charge-ordered phase exists at low disorder. The phase transition from the fluid to the charge ordered phase is consistent with the Random Field Ising universality class, which shows that the interaction is effectively screened at moderate temperature. Results from nonequilibrium simulations will also be briefly discussed. Reference: M.Goethe and M.Palassini, arXiv:0810.1047

  20. Filling Critical Gaps Through Innovative Cradle-to-Grave Training Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Burns, Pamela [North Central Texas Council of Governments; Dallas-Fort Worth Clean Cities; To, Kimberlin [North Central Texas Council of Governments; Dallas-Fort Worth Clean Cities

    2018-01-30

    This project seeks to enhance and provide training on alternative fuels and alternative fuel vehicles to reach mechanics/technicians, first responders, public safety officials, and other critical service providers across the multi-state region of Arkansas, Louisiana, Oklahoma, and Texas

  1. Research Notes ~ Second Language Acquisition Theories as a Framework for Creating Distance Learning Courses

    Directory of Open Access Journals (Sweden)

    Eileen N. Ariza

    2003-10-01

    Full Text Available Moore and Kearsley (1996 maintain distance educators should provide for three types of interaction: a learner-content; b learner-instructor; and c learner-learner. According to interactionist second language acquisition (SLA theories that reflect Krashen’s theory (1994 that comprehensible input is critical for second language acquisition, interaction can enhance second language acquisition and fluency. Effective output is necessary as well. We reviewed the research on distance learning for second language learners and concluded that SLA theories can, and should, be the framework that drives the development of courses for students seeking to learn languages by distance technology. This article delineates issues to consider in support of combining SLA theories and research literature as a guide in creating distance language learning courses.

  2. Gaps and pseudogaps in perovskite rare earth nickelates

    Directory of Open Access Journals (Sweden)

    S. James Allen

    2015-06-01

    Full Text Available We report on tunneling measurements that reveal the evolution of the quasiparticle state density in two rare earth perovskite nickelates, NdNiO3 and LaNiO3, that are close to a bandwidth controlled metal to insulator transition. We measure the opening of a sharp gap of ∼30 meV in NdNiO3 in its insulating ground state. LaNiO3, which remains a correlated metal at all practical temperatures, exhibits a pseudogap of the same order. The results point to both types of gaps arising from a common origin, namely, a quantum critical point associated with the T = 0 K metal-insulator transition. The results support theoretical models of the quantum phase transition in terms of spin and charge instabilities of an itinerant Fermi surface.

  3. Gap Resolution

    Energy Technology Data Exchange (ETDEWEB)

    2017-04-25

    Gap Resolution is a software package that was developed to improve Newbler genome assemblies by automating the closure of sequence gaps caused by repetitive regions in the DNA. This is done by performing the follow steps:1) Identify and distribute the data for each gap in sub-projects. 2) Assemble the data associated with each sub-project using a secondary assembler, such as Newbler or PGA. 3) Determine if any gaps are closed after reassembly, and either design fakes (consensus of closed gap) for those that closed or lab experiments for those that require additional data. The software requires as input a genome assembly produce by the Newbler assembler provided by Roche and 454 data containing paired-end reads.

  4. The Van der Waals-force-induced phononic band gap and resonant scattering in two-nanosphere aggregate

    International Nuclear Information System (INIS)

    Wu Jiuhui; Zhang Siwen; Zhou Kejiang

    2012-01-01

    A physical mechanism of phononic band gap and resonant nanoacoustic scattering in an aggregate of two elastic nanospheres is presented in this paper. By considering the Van der Waals (VdW) force between two nanospheres illuminated by nanoacoustic wave, phononic band gap and frequency shift at the lower frequency side, and largely enhanced nanoacoustic scattering at the other frequency range have been found through calculating the form function of the acoustic scattering from the nanosystem. This VdW-force-induced band gap is different from the known mechanisms of Bragg scattering and local resonances for periodic media. It is shown that when the separation distance between two nanospheres is decreasing from 20 to 1 nm, due to the increasing VdW force, the nanoacoustic scattering is much heightened by two order of magnitude, and meanwhile the frequency shift and phononic band gap at the low frequencies are both widened. These results could provide potential applications of nanoacoustic devices.

  5. Continuum absorption in the vicinity of the toroidicity-induced Alfvén gap

    International Nuclear Information System (INIS)

    Li, M.; Breizman, B. N.; Zheng, L. J.; Chen, Eugene Y.

    2015-01-01

    Excitation of Alfvén modes is commonly viewed as a concern for energetic particle confinement in burning plasmas. The 3.5 MeV alpha particles produced by fusion may be affected as well as other fast ions in both present and future devices. Continuum damping of such modes is one of the key factors that determine their excitation thresholds and saturation levels. This work examines the resonant dissipative response of the Alfvén continuum to an oscillating driving current when the driving frequency is slightly outside the edges of the toroidicity-induced spectral gap. The problem is largely motivated by the need to describe the continuum absorption in the frequency sweeping events. Akey element of this problem is the negative interference of the two closely spaced continuum crossing points.Weexplain why the lower and upper edges of the gap can have very different continuum absorption features. Lastly, the difference is associated with an eigenmode whose frequency can be arbitrarily close to the upper edge of the gap whereas the lower edge of the gap is always a finite distance away from the closest eigenmode

  6. Distance Education of Vocational High Schools in Turkey

    Directory of Open Access Journals (Sweden)

    Tuğçe GÜNTER

    2012-01-01

    Full Text Available The aim of vocational high schools is to teach qualified, high self-sufficient, self-confident, technical staff who have critical and mathematical thinking competence and who can utilize science and technology efficiently. However, because of the limitations of traditional education, students can not take enough education attendance. In this context; along with the advances in science and technology area, “Web- Based Distance Education Programme”, which provides equal education conditions to students, is developed. This programme has got great progresses in abroad, and has also started to practice in Turkish Vocational High Schools. It is determined that some Vocational High Schools have applied Web-Based Distance Education in Medical Documentation and Secretarial (MDS and Medical Laboratory Techniques (MLT Associate Degree Programmes which are also existed in Bülent Ecevit University (BEU Ahmet Erdoğan Health Services Vocational High School. It is observed that the universities, that implemented distance education in these associate degree programmes, have higher technical infrastructure and they design a constructivism-based modules. It is considered that this distance education programme for MDS and MLT Associate Degree Programmes in certain Vocational Schools, can also be implemented for students in Medical Documentation and Secretarial (MDS and Medical Laboratory Techniques (MLT which continues education by computers and overhead projector that is slightly different from traditional education.

  7. Quantum mechanical effects in plasmonic structures with subnanometre gaps.

    Science.gov (United States)

    Zhu, Wenqi; Esteban, Ruben; Borisov, Andrei G; Baumberg, Jeremy J; Nordlander, Peter; Lezec, Henri J; Aizpurua, Javier; Crozier, Kenneth B

    2016-06-03

    Metallic structures with nanogap features have proven highly effective as building blocks for plasmonic systems, as they can provide a wide tuning range of operating frequencies and large near-field enhancements. Recent work has shown that quantum mechanical effects such as electron tunnelling and nonlocal screening become important as the gap distances approach the subnanometre length-scale. Such quantum effects challenge the classical picture of nanogap plasmons and have stimulated a number of theoretical and experimental studies. This review outlines the findings of many groups into quantum mechanical effects in nanogap plasmons, and discusses outstanding challenges and future directions.

  8. Gap and impact of LMR [Liquid Metal Reactor] piping systems and reactor components

    International Nuclear Information System (INIS)

    Ma, D.C.; Gvildys, J.; Chang, Y.W.

    1987-01-01

    Because of high operation temperature, the LMR (Liquid Metal Reactor) plant is characterized by the thin-walled piping and components. Gaps are often present to allow free thermal expansion during normal plant operation. Under dynamic loadings, such as seismic excitation, if the relative displacement between the components exceeds the gap distance, impacts will occur. Since the components and piping become brittle over their design lifetime, impact is of important concern for it may lead to fractures of components and other serious effects. This paper deals with gap and impact problems in the LMR reactor components and piping systems. Emphasis is on the impacts due to seismic motion. Eight sections are contained in this paper. The gap and impact problems in LMR piping systems are described and a parametric study is performed on the effects of gap-induced support nonlinearity on the dynamics characteristics of the LMR piping systems. Gap and impact problems in the LMR reactor components are identified and their mathematical models are illustrated, and the gap and impact problems in the seismic reactor scram are discussed. The mathematical treatments of various impact models are also described. The uncertainties in the current seismic impact analyses of LMR components and structures are presented. An impact test on a 1/10-scale LMR thermal liner is described. The test results indicated that several clusters of natural modes can be excited by the impact force. The frequency content of the excited modes depends on the duration of the impact force; the shorter the duration, the higher the frequency content

  9. Evaluation of critical distances for energy transfer between Pr{sup 3+} and Ce{sup 3+} in yttrium aluminium garnet

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, Peng; Wei, Xiantao; Yin, Min; Chen, Yonghu, E-mail: yhuchen@ustc.edu.cn [Key Laboratory of Strongly-Coupled Quantum Matter Physics, Chinese Academy of Sciences, School of Physical Sciences, University of Science and Technology of China, No. 96 Jinzhai Road, Hefei, Anhui 230026 (China); Zhou, Shaoshuai [Key Laboratory of Strongly-Coupled Quantum Matter Physics, Chinese Academy of Sciences, School of Physical Sciences, University of Science and Technology of China, No. 96 Jinzhai Road, Hefei, Anhui 230026 (China); Department of Physics, Qufu Normal University, Qufu, Shandong 273165 (China)

    2016-09-07

    A series of Pr{sup 3+}/Ce{sup 3+} doped yttrium aluminium garnet (Y{sub 3}Al{sub 5}O{sub 12} or simply YAG) phosphors were synthesized to investigate the energy transfer between Pr{sup 3+} and Ce{sup 3+} for their potential application in a white light-emitting diode and quantum information storage and processing. The excitation and emission spectra of YAG:Pr{sup 3+}/Ce{sup 3+} were measured and analyzed, and it revealed that the reabsorption between Pr{sup 3+} and Ce{sup 3+} was so weak that it can be ignored, and the energy transfer from Pr{sup 3+} (5d) to Ce{sup 3+} (5d) and Ce{sup 3+} (5d) to Pr{sup 3+} ({sup 1}D{sub 2}) did occur. By analyzing the excitation and the emission spectra, the energy transfer from Pr{sup 3+} (5d) to Ce{sup 3+} (5d) and Ce{sup 3+} (5d) to Pr{sup 3+} ({sup 1}D{sub 2}) was examined in detail with an original strategy deduced from fluorescence dynamics and the Dexter energy transfer theory, and the critical distances of energy transfer were derived to be 7.9 Å and 4.0 Å for Pr{sup 3+} (5d) to Ce{sup 3+} (5d) and Ce{sup 3+} (5d) to Pr{sup 3+} ({sup 1}D{sub 2}), respectively. The energy transfer rates of the two processes of various concentrations were discussed and evaluated. Furthermore, for the purpose of sensing a single Pr{sup 3+} state with a Ce{sup 3+} ion, the optimal distance of Ce{sup 3+} from Pr{sup 3+} was evaluated as 5.60 Å, where the probability of success reaches its maximum value of 78.66%, and meanwhile the probabilities were evaluated for a series of Y{sup 3+} sites in a YAG lattice. These results will be of valuable reference for achievement of the optimal energy transfer efficiency in Pr{sup 3+}/Ce{sup 3+} doped YAG and other similar systems.

  10. Label-free detection of DNA hybridization and single point mutations in a nano-gap biosensor

    International Nuclear Information System (INIS)

    Zaffino, R L; Mir, M; Samitier, J

    2014-01-01

    We describe a conductance-based biosensor that exploits DNA-mediated long-range electron transport for the label-free and direct electrical detection of DNA hybridization. This biosensor platform comprises an array of vertical nano-gap biosensors made of gold and fabricated through standard photolithography combined with focused ion beam lithography. The nano-gap walls are covalently modified with short, anti-symmetric thiolated DNA probes, which are terminated by 19 bases complementary to both the ends of a target DNA strand. The nano-gaps are separated by a distance of 50nm, which was adjusted to fit the length of the DNA target plus the DNA probes. The hybridization of the target DNA closes the gap circuit in a switch on/off fashion, in such a way that it is readily detected by an increase in the current after nano-gap closure. The nano-biosensor shows high specificity in the discrimination of base-pair mismatching and does not require signal indicators or enhancing molecules. The design of the biosensor platform is applicable for multiplexed detection in a straightforward manner. The platform is well-suited to mass production, point-of-care diagnostics, and wide-scale DNA analysis applications. (paper)

  11. Teaching critical appraisal skills for nursing research.

    Science.gov (United States)

    Jones, Sandra C; Crookes, Patrick A; Johnson, Keryn M

    2011-09-01

    Evidence-based practice is a major focus in nursing, yet the literature continues to document a research-practice gap. Reasons for this gap stem partly from a lack of skills to critique and synthesize the literature, a lack of search skills and difficulty in understanding research articles, and limited knowledge of research by nursing professionals. An innovative and quality driven subject to improve critical appraisal and critical thinking skills was developed for the School of Nursing, Midwifery and Indigenous Health at the University of Wollongong, based on formative research with postgraduate students and supervisors. Through face-to-face and online teaching modules students worked through a structured process of analysing the key aspects of published papers using structured analysis tools for each study design. Pre and post surveys of students found improvements in perceived knowledge of all key skills of critical appraisal. External independent evaluation determined that it was a high quality subject showing many hallmarks of good assessment practice and good practice in use of information and communication technology (ICT) in support of the learning outcomes. Copyright © 2011 Elsevier Ltd. All rights reserved.

  12. A critical analysis of the literature and theoretical perspectives on theory-practice gap amongst newly qualified nurses within the United Kingdom.

    Science.gov (United States)

    Monaghan, Thomas

    2015-08-01

    This critical analysis of the literature examines the factors and theoretical perspectives contributing to the theory-practice gap for newly qualified nurses within the United Kingdom. This article aspires to inform, guide and promote effective nursing education both academically and practically. A systematic search strategy was conducted to identify relevant literature covering the period of 2000-2014, to include only contemporary theoretical perspectives coinciding with the dearth of contemporary literature post Project 2000. The literature was systematically investigated utilising nursing research databases, the Cumulative Index of Nursing and Allied Health Literature, Allied and Complementary Medicine, the U.S. National Library of Medicine and Internurse. To satisfy the search criteria only articles conducted within the United Kingdom and written in the English language were included. Only literature including nurses and newly qualified nurses were included. To identify relevant literature a series of key words were utilised. Systematic review of the literature revealed that newly qualified nurses feel unprepared for practice, lacking confidence in their own abilities. It was also felt by newly qualified nurses that not enough time was dedicated to the production of clinical skills during their training. The use of preceptorship programmes was found to reduce the transitional stress associated with becoming a qualified nursing practitioner. Despite the increasing research being undertaken in the area of theory-practice gap there is still a need for nursing educators, practice areas and regulatory bodies to invest further in research. The effects of preceptorship and simulation exercises in particular require more research to provide regulatory bodies with enough evidence to make an informed decision as to whether their use should be mandatory. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Detection and Evaluation of Pre-Preg Gaps and Overlaps in Glare Laminates

    Science.gov (United States)

    Nardi, Davide; Abouhamzeh, Morteza; Leonard, Rob; Sinke, Jos

    2018-03-01

    Gaps and overlaps between pre-preg plies represent common flaws in composite materials that can be introduced easily in an automated fibre placement manufacturing process and are potentially detrimental for the mechanical performances of the final laminates. Whereas gaps and overlaps have been addressed for full composite material, the topic has not been extended to a hybrid composite material such as Glare, a member of the family of Fibre Metal Laminates (FMLs). In this paper/research, the manufacturing, the detection, and the optical evaluation of intraply gaps and overlaps in Glare laminates are investigated. As part of an initial assessment study on the effect of gaps and overlaps on Glare, only the most critical lay-up has been considered. The experimental investigation started with the manufacturing of specimens having gaps and overlaps with different widths, followed by a non-destructive ultrasonic-inspection. An optical evaluation of the gaps and overlaps was performed by means of microscope image analysis of the cross sections of the specimens. The results from the non-destructive evaluations show the effectiveness of the ultrasonic detection of gaps and overlaps both in position, shape, width, and severity. The optical inspections confirm the accuracy of the non-destructive evaluation also adding useful insights about the geometrical features due to the presence of gaps and overlaps in the final Glare laminates. All the results justify the need for a further investigation on the effect of gaps and overlaps on the mechanical properties.

  14. Effect of the ratio of radial gap to radius of the coils on the transmission efficiency of wireless power transfer via coupled magnetic resonances

    Science.gov (United States)

    Gao, Pengfei; Tian, Zijian; Wang, Xuqi; Wu, Jun; Gui, Weifeng

    2018-03-01

    Wireless power transfer (WPT) via coupled magnetic resonance is a promising technology to be applied in many fields. In general, there will be a radial gap in practical application, and some special application environments need to limit the radius of the coils. Therefore, in this paper, considering the comprehensive analysis of the radial gap and the radius of the coils, the concept of the ratio of radial gap to the radius of the coils was proposed. Based on the circuit theory, the formula between the ratio and transmission efficiency of WPT was deduced, and the effects of the ratio on the transmission efficiency were studied respectively at different axial distances. Simulation experiments were carried out and the results not only demonstrate the influence law of the ratio on transmission efficiency, but also validate the value of the ratio which the axial distance has the greatest effect on the transmission efficiency. Besides, the results shows the relationship between the effect of the ratio on the efficiency and the effect of the axial distance on the efficiency. The experimental results show that the theoretical analysis is correct, thus providing an useful theoretical reference for the design and further research on the wireless power transfer system in complicated environment.

  15. Effect of the ratio of radial gap to radius of the coils on the transmission efficiency of wireless power transfer via coupled magnetic resonances

    Directory of Open Access Journals (Sweden)

    Pengfei Gao

    2018-03-01

    Full Text Available Wireless power transfer (WPT via coupled magnetic resonance is a promising technology to be applied in many fields. In general, there will be a radial gap in practical application, and some special application environments need to limit the radius of the coils. Therefore, in this paper, considering the comprehensive analysis of the radial gap and the radius of the coils, the concept of the ratio of radial gap to the radius of the coils was proposed. Based on the circuit theory, the formula between the ratio and transmission efficiency of WPT was deduced, and the effects of the ratio on the transmission efficiency were studied respectively at different axial distances. Simulation experiments were carried out and the results not only demonstrate the influence law of the ratio on transmission efficiency, but also validate the value of the ratio which the axial distance has the greatest effect on the transmission efficiency. Besides, the results shows the relationship between the effect of the ratio on the efficiency and the effect of the axial distance on the efficiency. The experimental results show that the theoretical analysis is correct, thus providing an useful theoretical reference for the design and further research on the wireless power transfer system in complicated environment.

  16. Presidential inability: Filling in the gaps.

    Science.gov (United States)

    Feerick, John D

    2014-01-01

    This article focuses on potential gaps caused by the absence from the Twenty-Fifth Amendment of provisions to deal with the disability of a Vice President and the omission from the statutory line of succession law of provisions comparable to Sections 3 and 4 of the Twenty-Fifth Amendment for when there is an able Vice President. The analysis offers a critical review of the latent ambiguities in the succession provision to the United States Constitution, noting problems that have arisen from the time of the Constitutional Convention, to John Tyler's accession to office, to numerous disability crises that presented themselves throughout the twentieth century, to the present day. As the world becomes more complex and threats to the presidency more common, continued examination of our succession structure and its adequacy for establishing clear and effective presidential succession provisions under a broad range of circumstances is of paramount concern. This article embraces this robust discussion by offering some suggestions for improving the system in a way that does not require a constitutional amendment. The first part of the analysis traces the events that have driven the development of the nation's succession procedures. The second part examines the inadequacies, or "gaps," that remain in the area of presidential inability, and the third part sets forth recommendations for resolving these gaps.

  17. The relation between mass-gap amplitudes and critical exponents in the Heisenberg model

    International Nuclear Information System (INIS)

    Alcaraz, F.C.; Felicio, J.R.D. de

    1985-01-01

    A recent result concerning the universality of the ratio of mass-gap amplitudes using the well known 1-D Heisenberg model which is the quantum version of the two-dimensional eight-vertex model is discussed. The believed extended scaling relation (x sub(p) = x sub(is an element of)/4) relating the polarization and energy anomalous dimensions is confirmed. The exponent, α, ν, γ sub(m) and γ sub(p) is also obtained by usual phenomenological renormalization group methods. (Author) [pt

  18. Reducing the distance in distance-caregiving by technology innovation

    Directory of Open Access Journals (Sweden)

    Lazelle E Benefield

    2007-07-01

    Full Text Available Lazelle E Benefield1, Cornelia Beck21College of Nursing, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA; 2Pat & Willard Walker Family Memory Research Center, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USAAbstract: Family caregivers are responsible for the home care of over 34 million older adults in the United States. For many, the elder family member lives more than an hour’s distance away. Distance caregiving is a growing alternative to more familiar models where: 1 the elder and the family caregiver(s may reside in the same household; or 2 the family caregiver may live nearby but not in the same household as the elder. The distance caregiving model involves elders and their family caregivers who live at some distance, defined as more than a 60-minute commute, from one another. Evidence suggests that distance caregiving is a distinct phenomenon, differs substantially from on-site family caregiving, and requires additional assistance to support the physical, social, and contextual dimensions of the caregiving process. Technology-based assists could virtually connect the caregiver and elder and provide strong support that addresses the elder’s physical, social, cognitive, and/or sensory impairments. Therefore, in today’s era of high technology, it is surprising that so few affordable innovations are being marketed for distance caregiving. This article addresses distance caregiving, proposes the use of technology innovation to support caregiving, and suggests a research agenda to better inform policy decisions related to the unique needs of this situation.Keywords: caregiving, family, distance, technology, elders

  19. Development of Multidimensional Gap Conductance model using Virtual Link Gap Element

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyo Chan; Yang, Yong Sik; Kim, Dae Ho; Bang, Je Geon; Kim, Sun Ki; Koo, Yang Hyun [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-10-15

    The gap conductance that determines temperature gradient between pellet and cladding can be quite sensitive to gap thickness. For instance, once the gap size increases up to several micrometers in certain region, difference of pellet surface temperatures increases up to 100 Kelvin. Therefore, iterative thermo-mechanical coupled analysis is required to solve temperature distribution throughout pellet and cladding. Recently, multidimensional fuel performance codes have been being developed in the advanced countries to evaluate thermal behavior of fuel for off normal conditions and DBA(design based accident) conditions using the Finite Element Method (FEM). FRAPCON-FRAPTRAN code system, which is well known as the verified and reliable code, incorporates 1D thermal module and multidimensional mechanical module. In this code, multidimensional gap conductance model is not applied. ALCYONE developed by CEA introduces equivalent heat convection coefficient that represents multidimensional gap conductance as a function of gap thickness. BISON, which is multidimensional fuel performance code developed by INL, owns multidimensional gap conductance model using projected thermal contact. In general, thermal contact algorithm is nonlinear calculation which is expensive approach numerically. The gap conductance model for multi-dimension is difficult issue in terms of convergence and nonlinearity because gap conductance is function of gap thickness which depends on mechanical analysis at each iteration step. In this paper, virtual link gap (VLG) element has been proposed to resolve convergence issue and nonlinear characteristic of multidimensional gap conductance. In terms of calculation accuracy and convergence efficiency, the proposed VLG model was evaluated. LWR fuel performance codes should incorporate thermo-mechanical loop to solve gap conductance problem, iteratively. However, gap conductance in multidimensional model is difficult issue owing to its nonlinearity and

  20. Experience in nuclear engineering distance education at the University of Tennessee

    International Nuclear Information System (INIS)

    Dodds, H.L.

    2011-01-01

    This paper describes the distance education programs in nuclear engineering at The University of Tennessee (UT), which includes several courses that are of interest to the mathematics and computation community such as reactor theory and design, shielding, statistics, health physics, and criticality safety. All of the courses needed for the MS degree in nuclear engineering and several of the courses needed for the PhD degree in nuclear engineering are delivered synchronously (i.e., interactive in real time) via the Internet to students located anywhere by instructors located anywhere. The paper will also describe the historical development of distance education programs at UT as well as the benefits of the programs to students and to the university. The oral presentation associated with this paper will include a short movie that demonstrates the technology used for distance delivery. (author)

  1. A likely planet-induced gap in the disc around T Cha

    Science.gov (United States)

    Hendler, Nathanial P.; Pinilla, Paola; Pascucci, Ilaria; Pohl, Adriana; Mulders, Gijs; Henning, Thomas; Dong, Ruobing; Clarke, Cathie; Owen, James; Hollenbach, David

    2018-03-01

    We present high-resolution (0.11 × 0.06 arcsec2) 3 mm ALMA observations of the highly inclined transition disc around the star T Cha. Our continuum image reveals multiple dust structures: an inner disc, a spatially resolved dust gap, and an outer ring. When fitting sky-brightness models to the real component of the 3 mm visibilities, we infer that the inner emission is compact (≤1 au in radius), the gap width is between 18 and 28 au, and the emission from the outer ring peaks at ˜36 au. We compare our ALMA image with previously published 1.6 μm VLT/SPHERE imagery. This comparison reveals that the location of the outer ring is wavelength dependent. More specifically, the peak emission of the 3 mm ring is at a larger radial distance than that of the 1.6 μm ring, suggesting that millimeter-sized grains in the outer disc are located farther away from the central star than micron-sized grains. We discuss different scenarios to explain our findings, including dead zones, star-driven photoevaporation, and planet-disc interactions. We find that the most likely origin of the dust gap is from an embedded planet, and estimate - for a single planet scenario - that T Cha's gap is carved by a 1.2MJup planet.

  2. Censoring distances based on labeled cortical distance maps in cortical morphometry.

    Science.gov (United States)

    Ceyhan, Elvan; Nishino, Tomoyuki; Alexopolous, Dimitrios; Todd, Richard D; Botteron, Kelly N; Miller, Michael I; Ratnanather, J Tilak

    2013-01-01

    It has been demonstrated that shape differences in cortical structures may be manifested in neuropsychiatric disorders. Such morphometric differences can be measured by labeled cortical distance mapping (LCDM) which characterizes the morphometry of the laminar cortical mantle of cortical structures. LCDM data consist of signed/labeled distances of gray matter (GM) voxels with respect to GM/white matter (WM) surface. Volumes and other summary measures for each subject and the pooled distances can help determine the morphometric differences between diagnostic groups, however they do not reveal all the morphometric information contained in LCDM distances. To extract more information from LCDM data, censoring of the pooled distances is introduced for each diagnostic group where the range of LCDM distances is partitioned at a fixed increment size; and at each censoring step, the distances not exceeding the censoring distance are kept. Censored LCDM distances inherit the advantages of the pooled distances but also provide information about the location of morphometric differences which cannot be obtained from the pooled distances. However, at each step, the censored distances aggregate, which might confound the results. The influence of data aggregation is investigated with an extensive Monte Carlo simulation analysis and it is demonstrated that this influence is negligible. As an illustrative example, GM of ventral medial prefrontal cortices (VMPFCs) of subjects with major depressive disorder (MDD), subjects at high risk (HR) of MDD, and healthy control (Ctrl) subjects are used. A significant reduction in laminar thickness of the VMPFC in MDD and HR subjects is observed compared to Ctrl subjects. Moreover, the GM LCDM distances (i.e., locations with respect to the GM/WM surface) for which these differences start to occur are determined. The methodology is also applicable to LCDM-based morphometric measures of other cortical structures affected by disease.

  3. Censoring Distances Based on Labeled Cortical Distance Maps in Cortical Morphometry

    Directory of Open Access Journals (Sweden)

    Elvan eCeyhan

    2013-10-01

    Full Text Available It has been demonstrated that shape differences are manifested in cortical structures due to neuropsychiatric disorders. Such morphometric differences can be measured by labeled cortical distance mapping (LCDM which characterizes the morphometry of the laminar cortical mantle of cortical structures. LCDM data consist of signed/labeled distances of gray matter (GM voxels with respect to GM/white matter (WM surface. Volumes and other summary measures for each subject and the pooled distances can help determine the morphometric differences between diagnostic groups, however they do not reveal all the morphometric information con-tained in LCDM distances. To extract more information from LCDM data, censoring of the pooled distances is introduced for each diagnostic group where the range of LCDM distances is partitioned at a fixed increment size; and at each censoring step, the distances not exceeding the censoring distance are kept. Censored LCDM distances inherit the advantages of the pooled distances but also provide information about the location of morphometric differences which cannot be obtained from the pooled distances. However, at each step, the censored distances aggregate, which might confound the results. The influence of data aggregation is investigated with an extensive Monte Carlo simulation analysis and it is demonstrated that this influence is negligible. As an illustrative example, GM of ventral medial prefrontal cortices (VMPFCs of subjects with major depressive disorder (MDD, subjects at high risk (HR of MDD, and healthy control (Ctrl subjects are used. A significant reduction in laminar thickness of the VMPFC in MDD and HR subjects is observed compared to Ctrl subjects. Moreover, the GM LCDM distances (i.e., locations with respect to the GM/WM surface for which these differences start to occur are determined. The methodology is also applicable to LCDM-based morphometric measures of other cortical structures affected by disease.

  4. Training for Distance Teaching through Distance Learning.

    Science.gov (United States)

    Cadorath, Jill; Harris, Simon; Encinas, Fatima

    2002-01-01

    Describes a mixed-mode bachelor degree course in English language teaching at the Universidad Autonoma de Puebla (Mexico) that was designed to help practicing teachers write appropriate distance education materials by giving them the experience of being distance students. Includes a course outline and results of a course evaluation. (Author/LRW)

  5. Analysis of higher education policy frameworks for open and distance education in Pakistan.

    Science.gov (United States)

    Ellahi, Abida; Zaka, Bilal

    2015-04-01

    distance education policies. The criteria and findings are useful for the reviewers of policy proposals to identify the gaps where policy documents can be improved to bring the desired outcomes. © The Author(s) 2015.

  6. Protection motivation theory and social distancing behaviour in response to a simulated infectious disease epidemic.

    Science.gov (United States)

    Williams, Lynn; Rasmussen, Susan; Kleczkowski, Adam; Maharaj, Savi; Cairns, Nicole

    2015-01-01

    Epidemics of respiratory infectious disease remain one of the most serious health risks facing the population. Non-pharmaceutical interventions (e.g. hand-washing or wearing face masks) can have a significant impact on the course of an infectious disease epidemic. The current study investigated whether protection motivation theory (PMT) is a useful framework for understanding social distancing behaviour (i.e. the tendency to reduce social contacts) in response to a simulated infectious disease epidemic. There were 230 participants (109 males, 121 females, mean age 32.4 years) from the general population who completed self-report measures assessing the components of PMT. In addition, participants completed a computer game which simulated an infectious disease epidemic in order to provide a measure of social distancing behaviour. The regression analyses revealed that none of the PMT variables were significant predictors of social distancing behaviour during the simulation task. However, fear (β = .218, p < .001), response efficacy (β = .175, p < .01) and self-efficacy (β = .251, p < .001) were all significant predictors of intention to engage in social distancing behaviour. Overall, the PMT variables (and demographic factors) explain 21.2% of the variance in intention. The findings demonstrated that PMT was a useful framework for understanding intention to engage in social distancing behaviour, but not actual behaviour during the simulated epidemic. These findings may reflect an intention-behaviour gap in relation to social distancing behaviour.

  7. The compassion gap in UK universities

    Directory of Open Access Journals (Sweden)

    Kathryn Waddington

    2016-05-01

    Full Text Available Context: This critical reflection is set in the context of increasing marketisation in UK higher education, where students are seen as consumers, rather than learners with power. The paper explores the dark side of academic work and the compassion gap in universities, in order to make recommendations for practice development in higher education and the human services. Aims: The paper aims to show how reflexive dialogue can be used to enable the development of compassionate academic practice. Conclusions and implications for practice: Toxic environments and organisational cultures in higher education have compounded the crisis in compassionate care in the NHS. Implications for practice are: Narrative approaches and critical appreciative inquiry are useful methods with which to reveal, and rectify, failures of compassion Courageous conversations are required to challenge dysfunctional organisational systems and processes Leadership development programmes should include the application of skills of compassion in organisational settings

  8. Chinese FDI and psychic distance perceptions on regulations in the German renewable energy sector

    International Nuclear Information System (INIS)

    Vaccarini, Katiuscia; Lattemann, Christoph; Spigarelli, Francesca; Tavoletti, Ernesto

    2017-01-01

    Countries vary in dimensions such as culture, language, business practices, policy-making, regulations, etc. Research shows that distances between countries concerning these dimensions affect foreign direct investment (FDI) flows. The higher the distances, the higher the difficulties for businesses, as managers’ decision-making is based on their perception of those distances. This paper analyzes the perception of distances between China and Germany by surveying Chinese managers who invested in Germany in the renewable energy (RE) sector, using Child et al.’s (2009) measure of psychic distance (PD) as a guide. The RE sector is young and highly dynamic, and the dimensions of PD are constantly changing. Mismatches in the perception of PD ex ante and ex post the decision to engage in FDI may lead to possible FDI failure. We use a five-company multiple case study to analyze if Chinese managers perceive distances in various dimensions, particularly regulation-based, and if there is a mismatch of perceptions between the pre-market and post-market entry period to investigate if managers’ perceptions change over time. Our findings lead to recommendations for practitioners and international business scholars, and policy making in the RE sector, by showing that operationalizing the PD construct should be complemented by dynamic analysis. - Highlights: • Chinese managers investing in Germany cope with distances on various dimensions • Decision-making is based on managers’ perception of those distances • This is particularly true for the RE sector and the relative regulation-based dimensions • “Prior experience” is a moderating variable and impacts managers’ perceptions. • Literature gap: perceptions vary over time and learning effects are detected.

  9. Tourists consuming distance

    DEFF Research Database (Denmark)

    Larsen, Gunvor Riber

    The environmental impact of tourism mobility is linked to the distances travelled in order to reach a holiday destination, and with tourists travelling more and further than previously, an understanding of how the tourists view the distance they travel across becomes relevant. Based on interviews...... contribute to an understanding of how it is possible to change tourism travel behaviour towards becoming more sustainable. How tourists 'consume distance' is discussed, from the practical level of actually driving the car or sitting in the air plane, to the symbolic consumption of distance that occurs when...... travelling on holiday becomes part of a lifestyle and a social positioning game. Further, different types of tourist distance consumers are identified, ranging from the reluctant to the deliberate and nonchalant distance consumers, who display very differing attitudes towards the distance they all travel...

  10. Analytic processing of distance.

    Science.gov (United States)

    Dopkins, Stephen; Galyer, Darin

    2018-01-01

    How does a human observer extract from the distance between two frontal points the component corresponding to an axis of a rectangular reference frame? To find out we had participants classify pairs of small circles, varying on the horizontal and vertical axes of a computer screen, in terms of the horizontal distance between them. A response signal controlled response time. The error rate depended on the irrelevant vertical as well as the relevant horizontal distance between the test circles with the relevant distance effect being larger than the irrelevant distance effect. The results implied that the horizontal distance between the test circles was imperfectly extracted from the overall distance between them. The results supported an account, derived from the Exemplar Based Random Walk model (Nosofsky & Palmieri, 1997), under which distance classification is based on the overall distance between the test circles, with relevant distance being extracted from overall distance to the extent that the relevant and irrelevant axes are differentially weighted so as to reduce the contribution of irrelevant distance to overall distance. The results did not support an account, derived from the General Recognition Theory (Ashby & Maddox, 1994), under which distance classification is based on the relevant distance between the test circles, with the irrelevant distance effect arising because a test circle's perceived location on the relevant axis depends on its location on the irrelevant axis, and with relevant distance being extracted from overall distance to the extent that this dependency is absent. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Critical research gaps and recommendations to inform research prioritisation for more effective prevention and improved outcomes in colorectal cancer

    Science.gov (United States)

    Lawler, Mark; Alsina, Deborah; Adams, Richard A; Anderson, Annie S; Brown, Gina; Fearnhead, Nicola S; Fenwick, Stephen W; Hochhauser, Daniel; Koelzer, Viktor H; McNair, Angus G K; Norton, Christine; Novelli, Marco R; Steele, Robert J C; Thomas, Anne L; Wilde, Lisa M; Wilson, Richard H

    2018-01-01

    Objective Colorectal cancer (CRC) leads to significant morbidity/mortality worldwide. Defining critical research gaps (RG), their prioritisation and resolution, could improve patient outcomes. Design RG analysis was conducted by a multidisciplinary panel of patients, clinicians and researchers (n=71). Eight working groups (WG) were constituted: discovery science; risk; prevention; early diagnosis and screening; pathology; curative treatment; stage IV disease; and living with and beyond CRC. A series of discussions led to development of draft papers by each WG, which were evaluated by a 20-strong patient panel. A final list of RGs and research recommendations (RR) was endorsed by all participants. Results Fifteen critical RGs are summarised below: RG1: Lack of realistic models that recapitulate tumour/tumour micro/macroenvironment; RG2: Insufficient evidence on precise contributions of genetic/environmental/lifestyle factors to CRC risk; RG3: Pressing need for prevention trials; RG4: Lack of integration of different prevention approaches; RG5: Lack of optimal strategies for CRC screening; RG6: Lack of effective triage systems for invasive investigations; RG7: Imprecise pathological assessment of CRC; RG8: Lack of qualified personnel in genomics, data sciences and digital pathology; RG9: Inadequate assessment/communication of risk, benefit and uncertainty of treatment choices; RG10: Need for novel technologies/interventions to improve curative outcomes; RG11: Lack of approaches that recognise molecular interplay between metastasising tumours and their microenvironment; RG12: Lack of reliable biomarkers to guide stage IV treatment; RG13: Need to increase understanding of health related quality of life (HRQOL) and promote residual symptom resolution; RG14: Lack of coordination of CRC research/funding; RG15: Lack of effective communication between relevant stakeholders. Conclusion Prioritising research activity and funding could have a significant impact on reducing CRC

  12. Distance learning and the internet in respiratory therapy education.

    Science.gov (United States)

    Varekojis, Sarah M; Sergakis, Georgianna G; Dunlevy, Crystal L; Foote, Elbie; Clutter, Jill

    2011-11-01

    The profession of respiratory therapy (RT) continues to grow both in number, due to population growth and an ever-increasing aging population, and scope of practice, due to both new and expanded roles and responsibilities in divergent areas of clinical practice. Instructional technology, including distance learning, will probably play a key role in training, educating, and assessing RT students to meet the increasing demand for practitioners. To assess current uses of distance learning and opinions concerning the appropriate use of distance education in RT education programs nationwide. A 13-item on-line survey was designed to collect information about the frequency of use of various types of distance education typically utilized in RT education programs. The survey was sent to directors of 343 Committee on Accreditation for Respiratory Care accredited programs of RT education that offer entry-level or advanced courses of study. The response rate was 50% (169 respondents). Fifty-two percent of the respondents indicated that their courses included some form of on-line learning component. Most directors anticipated that the distance composition of their course offerings will remain unchanged or increase in the near future. Our results indicate that, while distance education plays an important supportive role in RT education, there is still a preference for face-to-face instruction and Internet-facilitated courses among program directors. Program directors continue to view the laboratory and clinical settings as hands-on environments that require instructor supervision in order for students to demonstrate proficiency and critical thinking skills. When used appropriately, distance learning may be an efficient and effective approach to address the many barriers to education faced by the health workforce in general, including budget constraints, overloaded schedules, the need for on-the-job learning opportunities, and lack of access.

  13. Distancing, not embracing, the Distancing-Embracing model of art reception.

    Science.gov (United States)

    Davies, Stephen

    2017-01-01

    Despite denials in the target article, the Distancing-Embracing model appeals to compensatory ideas in explaining the appeal of artworks that elicit negative affect. The model also appeals to the deflationary effects of psychological distancing. Having pointed to the famous rejection in the 1960s of the view that aesthetic experience involves psychological distancing, I suggest that "distance" functions here as a weak metaphor that cannot sustain the explanatory burden the theory demands of it.

  14. Critical Thinking, Bias and Feminist Philosophy: Building a Better Framework through Collaboration

    Directory of Open Access Journals (Sweden)

    Adam Dalgleish

    2017-12-01

    These are damning charges that warrant a response within critical thinking frameworks. We suggest that the broader critical thinking literature, primarily that found within contexts of critical pedagogy and dispositional schools, can and should be harnessed within the critical thinking literature to bridge the gap between classical and feminist thinkers. We highlight several methods by which philosophy can retain the functionality of critical thinking while mitigating the obstacles presented by feminist critics and highlight how the adoption of such methods not only improves critical thinking, but is also beneficial to philosophy, philosophers and feminists alike.

  15. A Sub-channel Analysis of a VHTR Fuel Block with Tin Gap-Filler

    International Nuclear Information System (INIS)

    Cho, Chung Ho; Kim, Yong Hee; Yi, Yong Sun; Kim, Hong Pyo

    2005-01-01

    In the Nuclear Hydrogen Development and Demonstration (NHDD) project, two types of VHTRs (Very High Temperature Reactors), prismatic or pebble bed, are under investigation as the nuclear heat source for hydrogen production. In general, the targeted coolant outlet temperature of VHTR is 950∼1000 .deg. C and the maximum allowable fuel temperature is 1250 .deg. C during the normal operation. In the case of the prismatic reactor (PMR), conventional fuel designs result in a small margin in the maximum fuel temperature. This is one of the biggest demerits of the prismatic type In this paper, a technique of lowering the maximum fuel temperature is suggested. The PMR fuel assembly is comprised of many coolant holes and fuel channels. Cylindrical fuel compacts are stacked inside the fuel channel. Consequently, there should be a physical gap between the fuel compact and graphite block, which is filled with the He gas in the conventional design. The heat transfer coefficient of the He gap is very poor, and this increases the fuel temperature substantially. In the proposed design measure, the gap is filled with a liquid metal, tin (Sn) that has a very high thermal conductivity. The effects of tin in the gap with gap distance variation in the viewpoint of thermal hydraulics are quantitatively discussed. Also, the effects of the variations of the axial power distribution are discussed

  16. Foundations of Distance Education. Third Edition. Routledge Studies in Distance Education.

    Science.gov (United States)

    Keegan, Desmond

    This text gives an overview of distance education for students, administrators, and practitioners in distance education. Chapter 1 discusses the study of distance education. Chapter 2 analyzes forms of nonconventional education (open, nontraditional) that may have similarities to distance education but are not to be identified with it. Chapter 3…

  17. modelling distances

    Directory of Open Access Journals (Sweden)

    Robert F. Love

    2001-01-01

    Full Text Available Distance predicting functions may be used in a variety of applications for estimating travel distances between points. To evaluate the accuracy of a distance predicting function and to determine its parameters, a goodness-of-fit criteria is employed. AD (Absolute Deviations, SD (Squared Deviations and NAD (Normalized Absolute Deviations are the three criteria that are mostly employed in practice. In the literature some assumptions have been made about the properties of each criterion. In this paper, we present statistical analyses performed to compare the three criteria from different perspectives. For this purpose, we employ the ℓkpθ-norm as the distance predicting function, and statistically compare the three criteria by using normalized absolute prediction error distributions in seventeen geographical regions. We find that there exist no significant differences between the criteria. However, since the criterion SD has desirable properties in terms of distance modelling procedures, we suggest its use in practice.

  18. Heterogeneous technologies, strategic groups and environmental efficiency technology gaps for European countries

    International Nuclear Information System (INIS)

    Kounetas, Konstantinos

    2015-01-01

    This paper measures technology (TG) and environmental efficiency technology gaps (EETGs) in 25 European countries over two distinct periods 2002 and 2008 examining the possible effect of adopted environmental regulations and the Kyoto protocol commitments on environmental efficiency technology gaps. However, the introduction of the metafrontier in our analysis puts into our discussion the role of heterogeneous technologies and its effect on the above-mentioned measures. Employing a directional distance function, we investigate whether there is an actual difference, in terms of environmental efficiency and efficiency performance, among European countries considering the technological frontiers under which they operate. The construction of individual frontiers has been realized employing a large number of variables that are highly correlated with countries' learning and absorbing capacity, new technological knowledge and using economic theory and classical frontier discrimination like developed vs. developing, North vs. South and participation in the Eurozone or not. The overall results indicate a crucial role of heterogeneous technologies for technology gaps in both periods. Moreover, a significant decrease for both measures, although in different percent, has been recorded emphasizing the key role of knowledge spillovers. -- Highlights: •We estimate technology gaps (TGs) for 25 EU countries in two distinct periods. •We estimate environmental efficiency technology gaps (EETGs). •We consider countries' technological capabilities with R&D, innovation and eco-innovation. •We test the effect of different frontier constitutions on TGs-EETGs. •We denote the specific role of knowledge spillovers

  19. TECHNOLOGIES AND PEDAGOGICAL MEDIATION IN DISTANCE HIGHER EDUCATION

    Directory of Open Access Journals (Sweden)

    Vilma Geni Slomsk

    2016-04-01

    Full Text Available This study investigated of the limits and possibilities of the pedagogical use of technologies in distance higher education according to the perceptions of professors working um a regular accounting course. Qualitative-descriptive research was done, with data collected by means of an online questionnaire with open-questions and then analyzed by means of content analysis. The following benefits of Distance Higher Education, according to the professors, were found: “the access to higher education”, “flexibility of time and physical space”, “student´s self-discipline and self-learning”. As critical points, they mentioned “lack of an online educational background of professors and students” and the “difficulty promoting professor/student interaction”. As a challenge, the professors mentioned “dealing with the absence of a direct relationship professor/student”, that is, the “face-toface situation", which is common in a classroom; the use of strategies and resources that promote the exchange of experiences and interaction”, the “student´s profile”, “lack of student´s maturity”, “self-discipline”. Therefore, it is concluded that digital media are also regarded by professors as mere instructional tools, which a fact that makes a more critical understanding of technologies and the use of their full potential, especially as a way of cultural expression and production.

  20. Optical study of the band structure of wurtzite GaP nanowires

    KAUST Repository

    Assali, S.

    2016-07-25

    We investigated the optical properties of wurtzite (WZ) GaP nanowires by performing photoluminescence (PL) and time-resolved PL measurements in the temperature range from 4 K to 300 K, together with atom probe tomography to identify residual impurities in the nanowires. At low temperature, the WZ GaP luminescence shows donor-acceptor pair emission at 2.115 eV and 2.088 eV, and Burstein-Moss band-filling continuum between 2.180 and 2.253 eV, resulting in a direct band gap above 2.170 eV. Sharp exciton α-β-γ lines are observed at 2.140–2.164–2.252 eV, respectively, showing clear differences in lifetime, presence of phonon replicas, and temperature-dependence. The excitonic nature of those peaks is critically discussed, leading to a direct band gap of ∼2.190 eV and to a resonant state associated with the γ-line ∼80 meV above the Γ8C conduction band edge.

  1. Optical study of the band structure of wurtzite GaP nanowires

    KAUST Repository

    Assali, S.; Greil, J.; Zardo, I.; Belabbes, Abderrezak; de Moor, M. W. A.; Koelling, S.; Koenraad, P. M.; Bechstedt, F.; Bakkers, E. P. A. M.; Haverkort, J. E. M.

    2016-01-01

    We investigated the optical properties of wurtzite (WZ) GaP nanowires by performing photoluminescence (PL) and time-resolved PL measurements in the temperature range from 4 K to 300 K, together with atom probe tomography to identify residual impurities in the nanowires. At low temperature, the WZ GaP luminescence shows donor-acceptor pair emission at 2.115 eV and 2.088 eV, and Burstein-Moss band-filling continuum between 2.180 and 2.253 eV, resulting in a direct band gap above 2.170 eV. Sharp exciton α-β-γ lines are observed at 2.140–2.164–2.252 eV, respectively, showing clear differences in lifetime, presence of phonon replicas, and temperature-dependence. The excitonic nature of those peaks is critically discussed, leading to a direct band gap of ∼2.190 eV and to a resonant state associated with the γ-line ∼80 meV above the Γ8C conduction band edge.

  2. Brownian distance covariance

    OpenAIRE

    Székely, Gábor J.; Rizzo, Maria L.

    2010-01-01

    Distance correlation is a new class of multivariate dependence coefficients applicable to random vectors of arbitrary and not necessarily equal dimension. Distance covariance and distance correlation are analogous to product-moment covariance and correlation, but generalize and extend these classical bivariate measures of dependence. Distance correlation characterizes independence: it is zero if and only if the random vectors are independent. The notion of covariance with...

  3. Variability of inter-team distances associated with match events in elite-standard soccer

    NARCIS (Netherlands)

    Frencken, Wouter; De Poel, Harjo; Visscher, Chris; Lemmink, Koen

    2012-01-01

    In soccer, critical match events like goal attempts can be preceded by periods of instability in the balance between the two teams' behaviours. Therefore, we determined periods of high variability in the distance between the teams' centroid positions longitudinally and laterally in an

  4. Traversing psychological distance.

    Science.gov (United States)

    Liberman, Nira; Trope, Yaacov

    2014-07-01

    Traversing psychological distance involves going beyond direct experience, and includes planning, perspective taking, and contemplating counterfactuals. Consistent with this view, temporal, spatial, and social distances as well as hypotheticality are associated, affect each other, and are inferred from one another. Moreover, traversing all distances involves the use of abstraction, which we define as forming a belief about the substitutability for a specific purpose of subjectively distinct objects. Indeed, across many instances of both abstraction and psychological distancing, more abstract constructs are used for more distal objects. Here, we describe the implications of this relation for prediction, choice, communication, negotiation, and self-control. We ask whether traversing distance is a general mental ability and whether distance should replace expectancy in expected-utility theories. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. [Research progress of larger flexion gap than extension gap in total knee arthroplasty].

    Science.gov (United States)

    Zhang, Weisong; Hao, Dingjun

    2017-05-01

    To summarize the progress of larger flexion gap than extension gap in total knee arthro-plasty (TKA). The domestic and foreign related literature about larger flexion gap than extension gap in TKA, and its impact factors, biomechanical and kinematic features, and clinical results were summarized. During TKA, to adjust the relations of flexion gap and extension gap is one of the key factors of successful operation. The biomechanical, kinematic, and clinical researches show that properly larger flexion gap than extension gap can improve both the postoperative knee range of motion and the satisfaction of patients, but does not affect the stability of the knee joint. However, there are also contrary findings. So adjustment of flexion gap and extension gap during TKA is still in dispute. Larger flexion gap than extension gap in TKA is a new joint space theory, and long-term clinical efficacy, operation skills, and related complications still need further study.

  6. Reliability and Validity of the Workplace Social Distance Scale

    OpenAIRE

    Yoshii, Hatsumi; Mandai, Nozomu; Saito, Hidemitsu; Akazawa, Kouhei

    2014-01-01

    Self-stigma, defined by a negative attitude toward oneself combined with the consciousness of being a target of prejudice, is a critical problem for psychiatric patients. Self-stigma studies among psychiatric patients have indicated that high stigma is predictive of detrimental effects such as the delay of treatment and decreases in social participation in patients, and levels of self-stigma should be statistically evaluated. In this study, we developed the Workplace Social Distance Scale (WS...

  7. Acoustic beam splitting in a sonic crystal around a directional band gap

    International Nuclear Information System (INIS)

    Cicek Ahmet; Kaya Olgun Adem; Ulug Bulent

    2013-01-01

    Beam splitting upon refraction in a triangular sonic crystal composed of aluminum cylinders in air is experimentally and numerically demonstrated to occur due to finite source size, which facilitates circumvention of a directional band gap. Experiments reveal that two distinct beams emerge at crystal output, in agreement with the numerical results obtained through the finite-element method. Beam splitting occurs at sufficiently-small source sizes comparable to lattice periodicity determined by the spatial gap width in reciprocal space. Split beams propagate in equal amplitude, whereas beam splitting is destructed for oblique incidence above a critical incidence angle

  8. Gap Junctions

    Science.gov (United States)

    Nielsen, Morten Schak; Axelsen, Lene Nygaard; Sorgen, Paul L.; Verma, Vandana; Delmar, Mario; Holstein-Rathlou, Niels-Henrik

    2013-01-01

    Gap junctions are essential to the function of multicellular animals, which require a high degree of coordination between cells. In vertebrates, gap junctions comprise connexins and currently 21 connexins are known in humans. The functions of gap junctions are highly diverse and include exchange of metabolites and electrical signals between cells, as well as functions, which are apparently unrelated to intercellular communication. Given the diversity of gap junction physiology, regulation of gap junction activity is complex. The structure of the various connexins is known to some extent; and structural rearrangements and intramolecular interactions are important for regulation of channel function. Intercellular coupling is further regulated by the number and activity of channels present in gap junctional plaques. The number of connexins in cell-cell channels is regulated by controlling transcription, translation, trafficking, and degradation; and all of these processes are under strict control. Once in the membrane, channel activity is determined by the conductive properties of the connexin involved, which can be regulated by voltage and chemical gating, as well as a large number of posttranslational modifications. The aim of the present article is to review our current knowledge on the structure, regulation, function, and pharmacology of gap junctions. This will be supported by examples of how different connexins and their regulation act in concert to achieve appropriate physiological control, and how disturbances of connexin function can lead to disease. © 2012 American Physiological Society. Compr Physiol 2:1981-2035, 2012. PMID:23723031

  9. Correlation of optical energy gap with the nearest neighbour short range order in amorphous V2O5 films

    International Nuclear Information System (INIS)

    Dhawan, Sahil; Vedeshwar, Agnikumar G; Tandon, R P

    2011-01-01

    The optical and structural properties of well characterized vacuum-evaporated amorphous V 2 O 5 films were studied in the thickness range 5-500 nm. The structural analyses show that V-O, O-O and V-V nearest neighbour distances defining the short range order vary nonlinearly with film thickness. The optical absorption shows thickness-dependent energy gap (E g ) and the nonlinear behaviour of thickness-dependent E g is similar to that of nearest neighbour distance with film thickness. The E g correlates linearly very well with all the three nearest neighbour distances. The variation of E g with film thickness is attributed to the residual stress in the film which causes the changes in short range order. The change in E g corresponding to the change in V-O distance was found to be 35 eV nm -1 . This change is almost three times of that with V-V distance.

  10. The SI-Gap: How British Units Are Impeding Advances in STEM

    Science.gov (United States)

    Jones, M. P.; Cook, Courtney J.

    2017-11-01

    The United States is one of only three countries in the world that remain uncommitted to the metric system. Perhaps to policymakers the decision to hang on to miles, pounds, and gallons is one of tradition. However, as a physics teacher I have seen firsthand how growing up with U.S. Customary Units (commonly called by the pseudonym "British Units") has negatively impacted my students. Sure, they can convert between "British" and SI units; and they can effectively toggle between SI prefixes. However, they typically lack intuition regarding the values they express in SI. This is a major problem, but is by no means a criticism against them. Their disadvantage is the result of a unique learning gap that exists in the United States. I call it the SI(sī)-gap. The SI-gap not only impedes our ability as teachers to inspire students when it comes to science, technology, engineering, and mathematics (STEM); it also prevents our students from properly assessing the validity of their own results. As we shall soon see, the SI-gap carries consequences beyond the classroom. If we are to solve the problems that relate to the SI-gap, we need to reform the way we introduce SI units to the current generation of students.

  11. Metabolic Acidosis and Strong Ion Gap in Critically Ill Patients with Acute Kidney Injury

    Directory of Open Access Journals (Sweden)

    Cai-Mei Zheng

    2014-01-01

    Full Text Available Purpose. To determine the influence of physicochemical parameters on survival in metabolic acidosis (MA and acute kidney injury (AKI patients. Materials and Methods. Seventy-eight MA patients were collected and assigned to AKI or non-AKI group. We analyzed the physiochemical parameters on survival at 24 h, 72 h, 1 week, 1 month, and 3 months after AKI. Results. Mortality rate was higher in the AKI group. AKI group had higher anion gap (AG, strong ion gap (SIG, and apparent strong ion difference (SIDa values than non-AKI group. SIG value was higher in the AKI survivors than nonsurvivors and this value was correlated serum creatinine, phosphate, albumin, and chloride levels. SIG and serum albumin are negatively correlated with Acute Physiology and Chronic Health Evaluation IV scores. AG was associated with mortality at 1 and 3 months post-AKI, whereas SIG value was associated with mortality at 24 h, 72 h, 1 week, 1 month, and 3 months post-AKI. Conclusions. Whether high or low SIG values correlate with mortality in MA patients with AKI depends on its correlation with serum creatinine, chloride, albumin, and phosphate (P levels. AG predicts short-term mortality and SIG value predicts both short- and long-term mortality among MA patients with AKI.

  12. Benchmarking Distance Control and Virtual Drilling for Lateral Skull Base Surgery.

    Science.gov (United States)

    Voormolen, Eduard H J; Diederen, Sander; van Stralen, Marijn; Woerdeman, Peter A; Noordmans, Herke Jan; Viergever, Max A; Regli, Luca; Robe, Pierre A; Berkelbach van der Sprenkel, Jan Willem

    2018-01-01

    Novel audiovisual feedback methods were developed to improve image guidance during skull base surgery by providing audiovisual warnings when the drill tip enters a protective perimeter set at a distance around anatomic structures ("distance control") and visualizing bone drilling ("virtual drilling"). To benchmark the drill damage risk reduction provided by distance control, to quantify the accuracy of virtual drilling, and to investigate whether the proposed feedback methods are clinically feasible. In a simulated surgical scenario using human cadavers, 12 unexperienced users (medical students) drilled 12 mastoidectomies. Users were divided into a control group using standard image guidance and 3 groups using distance control with protective perimeters of 1, 2, or 3 mm. Damage to critical structures (sigmoid sinus, semicircular canals, facial nerve) was assessed. Neurosurgeons performed another 6 mastoidectomy/trans-labyrinthine and retro-labyrinthine approaches. Virtual errors as compared with real postoperative drill cavities were calculated. In a clinical setting, 3 patients received lateral skull base surgery with the proposed feedback methods. Users drilling with distance control protective perimeters of 3 mm did not damage structures, whereas the groups using smaller protective perimeters and the control group injured structures. Virtual drilling maximum cavity underestimations and overestimations were 2.8 ± 0.1 and 3.3 ± 0.4 mm, respectively. Feedback methods functioned properly in the clinical setting. Distance control reduced the risks of drill damage proportional to the protective perimeter distance. Errors in virtual drilling reflect spatial errors of the image guidance system. These feedback methods are clinically feasible. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. An Economic Evaluation of Food Safety Education Interventions: Estimates and Critical Data Gaps.

    Science.gov (United States)

    Zan, Hua; Lambea, Maria; McDowell, Joyce; Scharff, Robert L

    2017-08-01

    The economic evaluation of food safety interventions is an important tool that practitioners and policy makers use to assess the efficacy of their efforts. These evaluations are built on models that are dependent on accurate estimation of numerous input variables. In many cases, however, there is no data available to determine input values and expert opinion is used to generate estimates. This study uses a benefit-cost analysis of the food safety component of the adult Expanded Food and Nutrition Education Program (EFNEP) in Ohio as a vehicle for demonstrating how results based on variable values that are not objectively determined may be sensitive to alternative assumptions. In particular, the focus here is on how reported behavioral change is translated into economic benefits. Current gaps in the literature make it impossible to know with certainty how many people are protected by the education (what are the spillover effects?), the length of time education remains effective, and the level of risk reduction from change in behavior. Based on EFNEP survey data, food safety education led 37.4% of participants to improve their food safety behaviors. Under reasonable default assumptions, benefits from this improvement significantly outweigh costs, yielding a benefit-cost ratio of between 6.2 and 10.0. Incorporation of a sensitivity analysis using alternative estimates yields a greater range of estimates (0.2 to 56.3), which highlights the importance of future research aimed at filling these research gaps. Nevertheless, most reasonable assumptions lead to estimates of benefits that justify their costs.

  14. Gap features of layered iron-selenium-tellurium compound below and above the superconducting transition temperature by break-junction spectroscopy combined with STS

    Science.gov (United States)

    Ekino, T.; Sugimoto, A.; Gabovich, A. M.

    2018-05-01

    We studied correlations between the superconducting gap features of Te-substituted FeSe observed by scanning tunnelling spectroscopy (STS) and break-junction tunnelling spectroscopy (BJTS). At bias voltages outside the superconducting gap-energy range, the broad gap structure exists, which becomes the normal-state gap above the critical temperature, T c. Such behaviour is consistent with the model of the partially gapped density-wave superconductor involving both superconducting gaps and pseudogaps, which has been applied by us earlier to high-Tc cuprates. The similarity suggests that the parent electronic spectrum features should have much in common for these classes of materials.

  15. Mythic gaps

    Directory of Open Access Journals (Sweden)

    William Hansen

    2014-11-01

    Full Text Available Different kinds of omissions sometimes occur, or are perceived to occur, in traditional narratives and in tradition-inspired literature. A familiar instance is when a narrator realizes that he or she does not fully remember the story that he or she has begun to tell, and so leaves out part of it, which for listeners may possibly result in an unintelligible narrative. But many instances of narrative gap are not so obvious. From straightforward, objective gaps one can distinguish less-obvious subjective gaps: in many cases narrators do not leave out anything crucial or truly relevant from their exposition, and yet readers perceive gaps and take steps to fill them. The present paper considers four examples of subjective gaps drawn from ancient Greek literature (the Pandora myth, ancient Roman literature (the Pygmalion legend, ancient Hebrew literature (the Joseph legend, and early Christian literature (the Jesus legend. I consider the quite varied ways in which interpreters expand the inherited texts of these stories, such as by devising names, manufacturing motives, creating backstories, and in general filling in biographical ellipses. Finally, I suggest an explanation for the phenomenon of subjective gaps, arguing that, despite their variety, they have a single cause.

  16. Long-distance travellers stopover for longer: a case study with spoonbills staying in North Iberia

    OpenAIRE

    Navedo , Juan G.; Orizaola , Germán; Masero , José A.; Overdijk , Otto; Sánchez-Guzmán , Juan M.

    2010-01-01

    Abstract Long-distance migration is widespread among birds, connecting breeding and wintering areas through a set of stopover localities where individuals refuel and/or rest. The extent of the stopover is critical in determining the migratory strategy of a bird. Here, we examined the relationship between minimum length of stay of PVC-ringed birds in a major stopover site and the remaining flight distance to the overwintering area in the Eurasian spoonbill (Platalea l. leucorodia) d...

  17. Open and Distance Learning Today. Routledge Studies in Distance Education Series.

    Science.gov (United States)

    Lockwood, Fred, Ed.

    This book contains the following papers on open and distance learning today: "Preface" (Daniel); "Big Bang Theory in Distance Education" (Hawkridge); "Practical Agenda for Theorists of Distance Education" (Perraton); "Trends, Directions and Needs: A View from Developing Countries" (Koul); "American…

  18. The mass gap, the confining string and the physics of (lattice) topology

    International Nuclear Information System (INIS)

    Teper, M.

    1985-01-01

    The authors summarize some recent (Monte Carlo) calculations of the mass gap and string tension in SU(3) (lattice) gauge theory. In the range of couplings where both are measured, 5.5 ≤ β ≤ 5.9, the authors find no universal β(g) function, but the mass gap shows asymptotic scaling. The authors show how to use the finite lattice-size dependence of these quantities to extract the triple scalar-glueball coupling, g/sup 2//4π, and to obtain evidence for simple string physics at long distances. They then comment on the properties of topology on a lattice - in particular on the breakdown of the index theorem - and its (lack of) impact on quenched fermion physics. The authors construct a method for probing the underlying instanton structure of the full non-perturbative vacuum, and present evidence that such a structure is indeed there once the lattice spacing is small enough [β ≥ 2.7 in SU(2)]. The instantons the authors find are large - order inverse mass gap - and relatively stable against vacuum fluctuations, so that they may influence the non-perturbative physics of the theory

  19. Virtual Reality on a Desktop Hailed as New Tool in Distance Education.

    Science.gov (United States)

    Young, Jeffrey R.

    2000-01-01

    Describes college and university educational applications of desktop virtual reality to provide a more human touch to interactive distance education programs and impress the brain with more vivid images. Critics suggest the technology is too costly and time consuming and may even distract students from the content of an online course. (DB)

  20. Effect of actuating voltage and discharge gap on plasma assisted detonation initiation process

    Science.gov (United States)

    Siyin, ZHOU; Xueke, CHE; Wansheng, NIE; Di, WANG

    2018-06-01

    The influence of actuating voltage and discharge gap on plasma assisted detonation initiation by alternating current dielectric barrier discharge was studied in detail. A loose coupling method was used to simulate the detonation initiation process of a hydrogen–oxygen mixture in a detonation tube under different actuating voltage amplitudes and discharge gap sizes. Both the discharge products and the detonation forming process assisted by the plasma were analyzed. It was found that the patterns of the temporal and spatial distributions of discharge products in one cycle keep unchanged as changing the two discharge operating parameters. However, the adoption of a higher actuating voltage leads to a higher active species concentration within the discharge zone, and atom H is the most sensitive to the variations of the actuating voltage amplitude among the given species. Adopting a larger discharge gap results in a lower concentration of the active species, and all species have the same sensitivity to the variations of the gap. With respect to the reaction flow of the detonation tube, the corresponding deflagration to detonation transition (DDT) time and distance become slightly longer when a higher actuating voltage is chosen. The acceleration effect of plasma is more prominent with a smaller discharge gap, and the benefit builds gradually throughout the DDT process. Generally, these two control parameters have little effect on the amplitude of the flow field parameters, and they do not alter the combustion degree within the reaction zone.

  1. Gap-crossing behavior in a standardized and a nonstandardized jumping stone configuration

    NARCIS (Netherlands)

    Sporrel, Karlijn; Caljouw, Simone R.; Withagen, Rob

    2017-01-01

    Over the last years, the omnipresent standardization of playgrounds - the distances between, for example, jumping stones tend to be equal - has been criticized by both scientists and architects. First, it has been argued that standardization fails to do justice to the variability in the children's

  2. DISTANCE AND BLENDED LEARNING IN ASIA

    Directory of Open Access Journals (Sweden)

    Yasin OZARSLAN,

    2010-04-01

    Full Text Available Open and distance learning (ODL is one of the most important trends in education in Asia as well as all around the world. This book reviews ODL/ICT developments in schools, colleges, universities, open schooling, workplace training, professional development and non-formal adult and community education. It examines ODL and ICT experiences, successes and failures of Asian education and training.This is one of the comprehensive books on distance education applications in Asia. It is written by Colin Latchem and Insung Jung. Colin Latchem is an Australian-based consultant in open and distance learning. Insung Jung is Professor of Education, Media & Society at the International Christian University in Tokyo. The book's broader audience is anyone who is interested in ODL. If you are looking for on developments in ODL in Asia, this book is primarily for you. The book is consisted of 266 pages (+xiv covering 12 chapters with a conclusion part in each chapter.These conclusion parts provide a critical look at that chapter‘s issue Topics covered in the book are as follows: Technology, E-readiness And E-learning Readiness, Open Schooling, SchoolNets and Information and Communications Technology (ICT Integration in Classrooms, Higher Education, Lifelong Learning, Workplace Training, Professional Development and Non-Formal Adult and Community Education, New Providers and New Markets, ICT Integration In and Beyond the School, Instructional Design, Learner Support and Assessment in E-Learning, Leadership for Educational Change and Innovation, Quality Assurance and Accreditation, Staff Training and Development, Research, Publication and Translating Research into Practice.

  3. The Knowledge Gap Versus the Belief Gap and Abstinence-Only Sex Education.

    Science.gov (United States)

    Hindman, Douglas Blanks; Yan, Changmin

    2015-08-01

    The knowledge gap hypothesis predicts widening disparities in knowledge of heavily publicized public affairs issues among socioeconomic status groups. The belief gap hypothesis extends the knowledge gap hypothesis to account for knowledge and beliefs about politically contested issues based on empirically verifiable information. This analysis of 3 national surveys shows belief gaps developed between liberals and conservatives regarding abstinence-only sex education; socioeconomic status-based knowledge gaps did not widen. The findings partially support both belief gap and knowledge gap hypotheses. In addition, the unique contributions of exposure to Fox News, CNN, and MSNBC in this process were investigated. Only exposure to Fox News was linked to beliefs about abstinence-only sex education directly and indirectly through the cultivation of conservative ideology.

  4. The humanization of technology and science in distance learning

    Science.gov (United States)

    Voelzke, Marcos Rincon; Rodrigues Ferreira, Orlando

    2016-07-01

    The Distance Education [DE] presents significant growth in graduates and postgraduates programs. Regarding this fact, new challenges arise and others must be considered, as the generation gap between digital immigrants and digital natives, the establishment of a population increasingly accustomed to Information and Communication Technologies [ICT] and teaching methodologies that should be used and developed. Vygotsky's model of social interaction related to mediation can and should be used in DE, and concerning historical, social and cultural approaches affecting Brazilian reality, Paulo Freire is still up-to-date, integrating humanization into the use of ICT. This work only proceeds with analyses of these elements, being an excerpt of the master's dissertation of one of the authors [Ferreira], under the guidance of another [Voelzke].

  5. Robust band gap and half-metallicity in graphene with triangular perforations

    Science.gov (United States)

    Gregersen, Søren Schou; Power, Stephen R.; Jauho, Antti-Pekka

    2016-06-01

    Ideal graphene antidot lattices are predicted to show promising band gap behavior (i.e., EG≃500 meV) under carefully specified conditions. However, for the structures studied so far this behavior is critically dependent on superlattice geometry and is not robust against experimentally realistic disorders. Here we study a rectangular array of triangular antidots with zigzag edge geometries and show that their band gap behavior qualitatively differs from the standard behavior which is exhibited, e.g., by rectangular arrays of armchair-edged triangles. In the spin unpolarized case, zigzag-edged antidots give rise to large band gaps compared to armchair-edged antidots, irrespective of the rules which govern the existence of gaps in armchair-edged antidot lattices. In addition the zigzag-edged antidots appear more robust than armchair-edged antidots in the presence of geometrical disorder. The inclusion of spin polarization within a mean-field Hubbard approach gives rise to a large overall magnetic moment at each antidot due to the sublattice imbalance imposed by the triangular geometry. Half-metallic behavior arises from the formation of spin-split dispersive states near the Fermi energy, reducing the band gaps compared to the unpolarized case. This behavior is also found to be robust in the presence of disorder. Our results highlight the possibilities of using triangular perforations in graphene to open electronic band gaps in systems with experimentally realistic levels of disorder, and furthermore, of exploiting the strong spin dependence of the system for spintronic applications.

  6. From a distance: implications of spontaneous self-distancing for adaptive self-reflection.

    Science.gov (United States)

    Ayduk, Ozlem; Kross, Ethan

    2010-05-01

    Although recent experimental work indicates that self-distancing facilitates adaptive self-reflection, it remains unclear (a) whether spontaneous self-distancing leads to similar adaptive outcomes, (b) how spontaneous self-distancing relates to avoidance, and (c) how this strategy impacts interpersonal behavior. Three studies examined these issues demonstrating that the more participants spontaneously self-distanced while reflecting on negative memories, the less emotional (Studies 1-3) and cardiovascular (Study 2) reactivity they displayed in the short term. Spontaneous self-distancing was also associated with lower emotional reactivity and intrusive ideation over time (Study 1). The negative association between spontaneous self-distancing and emotional reactivity was mediated by how participants construed their experience (i.e., less recounting relative to reconstruing) rather than avoidance (Studies 1-2). In addition, spontaneous self-distancing was associated with more problem-solving behavior and less reciprocation of negativity during conflicts among couples in ongoing relationships (Study 3). Although spontaneous self-distancing was empirically related to trait rumination, it explained unique variance in predicting key outcomes. 2010 APA, all rights reserved

  7. Regression analysis for bivariate gap time with missing first gap time data.

    Science.gov (United States)

    Huang, Chia-Hui; Chen, Yi-Hau

    2017-01-01

    We consider ordered bivariate gap time while data on the first gap time are unobservable. This study is motivated by the HIV infection and AIDS study, where the initial HIV contracting time is unavailable, but the diagnosis times for HIV and AIDS are available. We are interested in studying the risk factors for the gap time between initial HIV contraction and HIV diagnosis, and gap time between HIV and AIDS diagnoses. Besides, the association between the two gap times is also of interest. Accordingly, in the data analysis we are faced with two-fold complexity, namely data on the first gap time is completely missing, and the second gap time is subject to induced informative censoring due to dependence between the two gap times. We propose a modeling framework for regression analysis of bivariate gap time under the complexity of the data. The estimating equations for the covariate effects on, as well as the association between, the two gap times are derived through maximum likelihood and suitable counting processes. Large sample properties of the resulting estimators are developed by martingale theory. Simulations are performed to examine the performance of the proposed analysis procedure. An application of data from the HIV and AIDS study mentioned above is reported for illustration.

  8. The teacher training process through distance education: a pioneer experience

    Directory of Open Access Journals (Sweden)

    Oscar Massaru Fujita

    2016-06-01

    Full Text Available This paper presents briefly the actions conducted in the formation process and established partnerships to achieve the pioneering educational process of Distance Education (DE courses of the State University of Londrina (UEL-PR. The methodological design was developed according to the Qualitative Approach of Action-Research type that prioritizes the development and analysis of the process along with the "meaning" that people give to things and your life than actually the product itself. The data collected through questionnaires at the end of the course signal impressions (positive and constructive criticism we received and the meanings experienced teacher students (testimonials, chats, discussion forums, projects in the courses offered. The experience lived in these three courses: Virtual Learning Environment (60 hours; Tutoring in distance education (60 hours and Teaching Materials in Distance Education (60 hours, from its conception to its actual conclusion, make us think that we are on the right way and by TDIC, new horizons may open up to the institution in short- and medium-term.

  9. Distance-regular graphs

    NARCIS (Netherlands)

    van Dam, Edwin R.; Koolen, Jack H.; Tanaka, Hajime

    2016-01-01

    This is a survey of distance-regular graphs. We present an introduction to distance-regular graphs for the reader who is unfamiliar with the subject, and then give an overview of some developments in the area of distance-regular graphs since the monograph 'BCN'[Brouwer, A.E., Cohen, A.M., Neumaier,

  10. Economics of Distance and Online Learning Theory, Practice and Research

    Directory of Open Access Journals (Sweden)

    reviewed by TOJDE

    2009-10-01

    Full Text Available Economics of Distance and Online LearningTheory, Practice and ResearchBy William Bramble & Santosh PandaPrice: $125.00ISBN: 978-0-415-96388-6, Binding: Hardback, Publishedby: Routledge, New York, Publication Date: March 2008, Pages: 312TOJDEABOUT THE BOOKThis book provides a comprehensive overview of theorganizational models of distance and online learning froman international perspective and from the point of view ofeconomic planning, costing and management decisionmaking.The book points to directions for the further research anddevelopment in this area, and will promote furtherunderstanding and critical reflection on the part ofadministrators, practitioners and researchers of distanceeducation.The experiences and perspectives in distance education inthe US are balanced with those in other areas of the world.Table of ContentsPrefaceSECTION ONE: INTRODUCTIONChapter 1: Organizational and Cost Structures for Distanceand Online Learning, William J. Bramble and Santosh PandaSECTION TWO: PLANNING AND MANAGEMENTChapter 2: Changing Distance Education andChanging Organizational Issues, D. Randy Garrison and Heather KanukaChapter 3: Online Learning and the University, Chris Curran217Chapter 4: Virtual Schooling and Basic Education, Thomas ClarkChapter 5: Historical Perspectives on Distance Education in the United States, Paul J.Edelson and Von PittmanSECTION THREE: FUNDINGChapter 6: Funding of Distance and Online Learning in the United States, Mark J. Smithand William J. BrambleChapter 7: Funding Distance Education: A Regional Perspective, Santosh Panda andAshok GabaSECTION FOUR: COST STRUCTURES AND MODELSChapter 8: Costs and Quality of Online Learning, Alistair InglisChapter 9: Costing Virtual University Education, Insung JungChapter 10: Cost-Benefit of Student Retention Policies and Practices, Ormond SimpsonSECTION FIVE: DISTANCE TRAININGChapter 11: Cost Benefit of Online Learning, Zane Berge and Charlotte DonaldsonChapter 12: Transforming Workplace

  11. Hierarchical traits distances explain grassland Fabaceae species' ecological niches distances

    Science.gov (United States)

    Fort, Florian; Jouany, Claire; Cruz, Pablo

    2015-01-01

    Fabaceae species play a key role in ecosystem functioning through their capacity to fix atmospheric nitrogen via their symbiosis with Rhizobium bacteria. To increase benefits of using Fabaceae in agricultural systems, it is necessary to find ways to evaluate species or genotypes having potential adaptations to sub-optimal growth conditions. We evaluated the relevance of phylogenetic distance, absolute trait distance and hierarchical trait distance for comparing the adaptation of 13 grassland Fabaceae species to different habitats, i.e., ecological niches. We measured a wide range of functional traits (root traits, leaf traits, and whole plant traits) in these species. Species phylogenetic and ecological distances were assessed from a species-level phylogenetic tree and species' ecological indicator values, respectively. We demonstrated that differences in ecological niches between grassland Fabaceae species were related more to their hierarchical trait distances than to their phylogenetic distances. We showed that grassland Fabaceae functional traits tend to converge among species with the same ecological requirements. Species with acquisitive root strategies (thin roots, shallow root systems) are competitive species adapted to non-stressful meadows, while conservative ones (coarse roots, deep root systems) are able to tolerate stressful continental climates. In contrast, acquisitive species appeared to be able to tolerate low soil-P availability, while conservative ones need high P availability. Finally we highlight that traits converge along the ecological gradient, providing the assumption that species with similar root-trait values are better able to coexist, regardless of their phylogenetic distance. PMID:25741353

  12. Hierarchical traits distances explain grassland Fabaceae species’ ecological niches distances

    Directory of Open Access Journals (Sweden)

    Florian eFort

    2015-02-01

    Full Text Available Fabaceae species play a key role in ecosystem functioning through their capacity to fix atmospheric nitrogen via their symbiosis with Rhizobium bacteria. To increase benefits of using Fabaceae in agricultural systems, it is necessary to find ways to evaluate species or genotypes having potential adaptations to sub-optimal growth conditions. We evaluated the relevance of phylogenetic distance, absolute trait distance and hierarchical trait distance for comparing the adaptation of 13 grassland Fabaceae species to different habitats, i.e. ecological niches. We measured a wide range of functional traits (root traits, leaf traits and whole plant traits in these species. Species phylogenetic and ecological distances were assessed from a species-level phylogenetic tree and species’ ecological indicator values, respectively. We demonstrated that differences in ecological niches between grassland Fabaceae species were related more to their hierarchical trait distances than to their phylogenetic distances. We showed that grassland Fabaceae functional traits tend to converge among species with the same ecological requirements. Species with acquisitive root strategies (thin roots, shallow root systems are competitive species adapted to non-stressful meadows, while conservative ones (coarse roots, deep root systems are able to tolerate stressful continental climates. In contrast, acquisitive species appeared to be able to tolerate low soil-P availability, while conservative ones need high P availability. Finally we highlight that traits converge along the ecological gradient, providing the assumption that species with similar root-trait values are better able to coexist, regardless of their phylogenetic distance.

  13. Numerical distance protection

    CERN Document Server

    Ziegler, Gerhard

    2011-01-01

    Distance protection provides the basis for network protection in transmission systems and meshed distribution systems. This book covers the fundamentals of distance protection and the special features of numerical technology. The emphasis is placed on the application of numerical distance relays in distribution and transmission systems.This book is aimed at students and engineers who wish to familiarise themselves with the subject of power system protection, as well as the experienced user, entering the area of numerical distance protection. Furthermore it serves as a reference guide for s

  14. Cracked pellet gap conductance model: comparison of FRAP-S calculations with measured fuel centerline temperatures

    International Nuclear Information System (INIS)

    MacDonald, P.E.; Broughton, J.M.

    1975-03-01

    Fuel pellets crack extensively upon irradiation due both to thermal stresses induced by power changes and at high burnup, to accumulation of gaseous fission products at grain boundaries. Therefore, the distance between the fuel and cladding will be circumferentially nonuniform; varying between that calculated for intact operating fuel pellets and essentially zero (fuel segments in contact with the cladding wall). A model for calculation of temperatures in cracked pellets is proposed wherein the effective fuel to cladding gap conductance is calculated by taking a zero pressure contact conductance in series with an annular gap conductance. Comparisons of predicted and measured fuel centerline temperatures at beginning of life and at extended burnup are presented in support of the model. 13 references

  15. Hydrogen Safety Sensor Performance and Use Gap Analysis: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Buttner, William J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Burgess, Robert M [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Schmidt, Kara [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Hartmann, Kevin S [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Wright, Hannah [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Weidner, Eveline [Joint Research Centre, Petten, the Netherlands; Cebolla, Rafael O. [Joint Research Centre, Petten, the Netherlands; Bonato, Christian [Joint Research Centre, Petten, the Netherlands; Moretto, Pietro [Joint Research Centre, Petten, the Netherlands

    2017-11-15

    Hydrogen sensors are recognized as an important technology for facilitating the safe implementation of hydrogen as an alternative fuel, and there are numerous reports of a sensor alarm successfully preventing a potentially serious event. However, gaps in sensor metrological specifications, as well as in their performance for some applications, exist.The U.S. Department of Energy (DOE) Fuel Cell Technology Office published a short list of critical gaps in the 2007 and 2012 multiyear project plans; more detailed gap analyses were independently performed by the JRC and NREL. There have been, however, some significant advances in sensor technologies since these assessments, including the commercial availability of hydrogen sensors with fast response times (t90 less than 1 s, which had been an elusive DOE target since 2007), improved robustness to chemical poisons, improved selectivity, and improved lifetime and stability. These improvements, however, have not been universal and typically pertain to select platforms or models. Moreover, as hydrogen markets grow and new applications are being explored, more demands will be imposed on sensor performance. The hydrogen sensor laboratories at NREL and JRC are currently updating the hydrogen safety sensor gap analysis through direct interaction with international stakeholders in the hydrogen community, especially end-users. NREL and the JRC are currently organizing a series of workshops (in Europe and the U.S.) with sensor developers, end-users, and other stakeholders in 2017 to identify technology gaps and to develop a path forward to address them. One workshop is scheduled for May 10 in Brussels, Belgium at the Headquarters of the Fuel Cell and Hydrogen Joint Undertaking. A second workshop is planned at the National Renewable Energy Laboratory in Golden, CO, USA. This presentation will review improvements in sensor technologies in the past 5 to 10 years, identify gaps in sensor performance and use requirements, and identify

  16. Critical temperature for shape transition in hot nuclei within covariant density functional theory

    Science.gov (United States)

    Zhang, W.; Niu, Y. F.

    2018-05-01

    Prompted by the simple proportional relation between critical temperature for pairing transition and pairing gap at zero temperature, we investigate the relation between critical temperature for shape transition and ground-state deformation by taking even-even Cm-304286 isotopes as examples. The finite-temperature axially deformed covariant density functional theory with BCS pairing correlation is used. Since the Cm isotopes are the newly proposed nuclei with octupole correlations, we studied in detail the free energy surface, the Nilsson single-particle (s.p.) levels, and the components of s.p. levels near the Fermi level in 292Cm. Through this study, the formation of octupole equilibrium is understood by the contribution coming from the octupole driving pairs with Ω [N ,nz,ml] and Ω [N +1 ,nz±3 ,ml] for single-particle levels near the Fermi surfaces as it provides a good manifestation of the octupole correlation. Furthermore, the systematics of deformations, pairing gaps, and the specific heat as functions of temperature for even-even Cm-304286 isotopes are discussed. Similar to the relation between the critical pairing transition temperature and the pairing gap at zero temperature Tc=0.6 Δ (0 ) , a proportional relation between the critical shape transition temperature and the deformation at zero temperature Tc=6.6 β (0 ) is found for both octupole shape transition and quadrupole shape transition for the isotopes considered.

  17. The Distance Standard Deviation

    OpenAIRE

    Edelmann, Dominic; Richards, Donald; Vogel, Daniel

    2017-01-01

    The distance standard deviation, which arises in distance correlation analysis of multivariate data, is studied as a measure of spread. New representations for the distance standard deviation are obtained in terms of Gini's mean difference and in terms of the moments of spacings of order statistics. Inequalities for the distance variance are derived, proving that the distance standard deviation is bounded above by the classical standard deviation and by Gini's mean difference. Further, it is ...

  18. Scaling of Natal Dispersal Distances in Terrestrial Birds and Mammals

    Directory of Open Access Journals (Sweden)

    Glenn D. Sutherland

    2000-07-01

    Full Text Available Natal dispersal is a process that is critical in the spatial dynamics of populations, including population spread, recolonization, and gene flow. It is a central focus of conservation issues for many vertebrate species. Using data for 77 bird and 68 mammal species, we tested whether median and maximum natal dispersal distances were correlated with body mass, diet type, social system, taxonomic family, and migratory status. Body mass and diet type were found to predict both median and maximum natal dispersal distances in mammals: large species dispersed farther than small ones, and carnivorous species dispersed farther than herbivores and omnivores. Similar relationships occurred for carnivorous bird species, but not for herbivorous or omnivorous ones. Natal dispersal distances in birds or mammals were not significantly related to broad categories of social systems. Only in birds were factors such as taxonomic relatedness and migratory status correlated with natal dispersal, and then only for maximum distances. Summary properties of dispersal processes appeared to be derived from interactions among behavioral and morphological characteristics of species and from their linkages to the dynamics of resource availability in landscapes. In all the species we examined, most dispersers moved relatively short distances, and long-distance dispersal was uncommon. On the basis of these findings, we fit an empirical model based on the negative exponential distribution for calculating minimum probabilities that animals disperse particular distances from their natal areas. This model, coupled with knowledge of a species' body mass and diet type, can be used to conservatively predict dispersal distances for different species and examine possible consequences of large-scale habitat alterations on connectedness between populations. Taken together, our results can provide managers with the means to identify species vulnerable to landscape-level habitat changes

  19. Distance Education in Turkey

    Directory of Open Access Journals (Sweden)

    Dr. Nursel Selver RUZGAR,

    2004-04-01

    Full Text Available Distance Education in Turkey Assistant Professor Dr. Nursel Selver RUZGAR Technical Education Faculty Marmara University, TURKEY ABSTRACT Many countries of the world are using distance education with various ways, by internet, by post and by TV. In this work, development of distance education in Turkey has been presented from the beginning. After discussing types and applications for different levels of distance education in Turkey, the distance education was given in the cultural aspect of the view. Then, in order to create the tendencies and thoughts of graduates of Higher Education Institutions and Distance Education Institutions about being competitors in job markets, sufficiency of education level, advantages for education system, continuing education in different Institutions, a face-to-face survey was applied to 1284 graduates, 958 from Higher Education Institutions and 326 from Distance Education Institutions. The results were evaluated and discussed. In the last part of this work, suggestions to become widespread and improve the distance education in the country were made.

  20. Creative and Critical Thinking, Teamwork, and Tomorrow's Workplace

    Science.gov (United States)

    Gould, J. Christine; Schoonover, Patricia F.

    2009-01-01

    Creative and critical thinking have been identified by Isaksen, Dorval, and Treffinger (2000) as the ability to "perceive gaps, challenges, or concerns; think of many varied or unusual possibilities; or elaborate and extend alternatives," as well as make meaningful connections that include analyzing, evaluating, and developing options.…

  1. Vicariance, long-distance dispersal, and regional extinction-recolonization dynamics explain the disjunct circumpolar distribution of the arctic-alpine plant Silene acaulis.

    Science.gov (United States)

    Gussarova, Galina; Allen, Geraldine A; Mikhaylova, Yulia; McCormick, Laurie J; Mirré, Virginia; Marr, Kendrick L; Hebda, Richard J; Brochmann, Christian

    2015-10-01

    Many arctic-alpine species have vast geographic ranges, but these may encompass substantial gaps whose origins are poorly understood. Here we address the phylogeographic history of Silene acaulis, a perennial cushion plant with a circumpolar distribution except for a large gap in Siberia. We assessed genetic variation in a range-wide sample of 103 populations using plastid DNA (pDNA) sequences and AFLPs (amplified fragment length polymorphisms). We constructed a haplotype network and performed Bayesian phylogenetic analyses based on plastid sequences. We visualized AFLP patterns using principal coordinate analysis, identified genetic groups using the program structure, and estimated genetic diversity and rarity indices by geographic region. The history of the main pDNA lineages was estimated to span several glaciations. AFLP data revealed a distinct division between Beringia/North America and Europe/East Greenland. These two regions shared only one of 17 pDNA haplotypes. Populations on opposite sides of the Siberian range gap (Ural Mountains and Chukotka) were genetically distinct and appear to have resulted from postglacial leading-edge colonizations. We inferred two refugia in North America (Beringia and the southern Rocky Mountains) and two in Europe (central-southern Europe and northern Europe/East Greenland). Patterns in the East Atlantic region suggested transoceanic long-distance dispersal events. Silene acaulis has a highly dynamic history characterized by vicariance, regional extinction, and recolonization, with persistence in at least four refugia. Long-distance dispersal explains patterns across the Atlantic Ocean, but we found no evidence of dispersal across the Siberian range gap. © 2015 Botanical Society of America.

  2. Difficult relationships: critical pedagogies and curriculum

    Directory of Open Access Journals (Sweden)

    María Verónica Di Caudo Villoslada

    2013-07-01

    Full Text Available This paper reviews the proposals of the ‘critical pedagogies’ and presents some difficulties in the realization of their principles in the context of current public policies in Latin America. Distances between discourses and practices, absence of radically democratic educational policies, lack of awareness of critical pedagogies by teachers, lack of contextual production and indiscriminate use of the word critical—that ends up opposing everything that is considered as traditional pedagogy—makes us wonder about the real possibility of transformation in order to fight against the dominant power relationships through counter-hegemonic and destabilizing practices in education.

  3. Critical research gaps and recommendations to inform research prioritisation for more effective prevention and improved outcomes in colorectal cancer.

    Science.gov (United States)

    Lawler, Mark; Alsina, Deborah; Adams, Richard A; Anderson, Annie S; Brown, Gina; Fearnhead, Nicola S; Fenwick, Stephen W; Halloran, Stephen P; Hochhauser, Daniel; Hull, Mark A; Koelzer, Viktor H; McNair, Angus G K; Monahan, Kevin J; Näthke, Inke; Norton, Christine; Novelli, Marco R; Steele, Robert J C; Thomas, Anne L; Wilde, Lisa M; Wilson, Richard H; Tomlinson, Ian

    2018-01-01

    Colorectal cancer (CRC) leads to significant morbidity/mortality worldwide. Defining critical research gaps (RG), their prioritisation and resolution, could improve patient outcomes. RG analysis was conducted by a multidisciplinary panel of patients, clinicians and researchers (n=71). Eight working groups (WG) were constituted: discovery science; risk; prevention; early diagnosis and screening; pathology; curative treatment; stage IV disease; and living with and beyond CRC. A series of discussions led to development of draft papers by each WG, which were evaluated by a 20-strong patient panel. A final list of RGs and research recommendations (RR) was endorsed by all participants. Fifteen critical RGs are summarised below: RG1 : Lack of realistic models that recapitulate tumour/tumour micro/macroenvironment; RG2 : Insufficient evidence on precise contributions of genetic/environmental/lifestyle factors to CRC risk; RG3 : Pressing need for prevention trials; RG4 : Lack of integration of different prevention approaches; RG5 : Lack of optimal strategies for CRC screening; RG6 : Lack of effective triage systems for invasive investigations; RG7 : Imprecise pathological assessment of CRC; RG8 : Lack of qualified personnel in genomics, data sciences and digital pathology; RG9 : Inadequate assessment/communication of risk, benefit and uncertainty of treatment choices; RG10 : Need for novel technologies/interventions to improve curative outcomes; RG11 : Lack of approaches that recognise molecular interplay between metastasising tumours and their microenvironment; RG12 : Lack of reliable biomarkers to guide stage IV treatment; RG13 : Need to increase understanding of health related quality of life (HRQOL) and promote residual symptom resolution; RG14 : Lack of coordination of CRC research/funding; RG15 : Lack of effective communication between relevant stakeholders. Prioritising research activity and funding could have a significant impact on reducing CRC disease burden over

  4. Lyme disease ecology in a changing world: Consensus, uncertainty and critical gaps for improving control

    Science.gov (United States)

    Kilpatrick, A. Marm; Dobson, Andrew D.M.; Levi, Taal; Salkeld, Daniel J.; Swei, Andrea; Ginsberg, Howard; Kjemtrup, Anne; Padgett, Kerry A.; Jensen, Per A.; Fish, Durland; Ogden, Nick H.; Diuk-Wasser, Maria A.

    2017-01-01

    Lyme disease is the most common tick-borne disease in temperate regions of North America, Europe and Asia, and the number of reported cases has increased in many regions as landscapes have been altered. Although there has been extensive work on the ecology and epidemiology of this disease in both Europe and North America, substantial uncertainty exists about fundamental aspects that determine spatial and temporal variation in both disease risk and human incidence, which hamper effective and efficient prevention and control. Here we describe areas of consensus that can be built on, identify areas of uncertainty and outline research needed to fill these gaps to facilitate predictive models of disease risk and the development of novel disease control strategies. Key areas of uncertainty include: (i) the precise influence of deer abundance on tick abundance, (ii) how tick populations are regulated, (iii) assembly of host communities and tick-feeding patterns across different habitats, (iv) reservoir competence of host species, and (v) pathogenicity for humans of different genotypes of Borrelia burgdorferi. Filling these knowledge gaps will improve Lyme disease prevention and control and provide general insights into the drivers and dynamics of this emblematic multi-host–vector-borne zoonotic disease.

  5. Safety analysis of the Los Alamos critical experiments facility

    International Nuclear Information System (INIS)

    Paxton, H.C.

    1975-10-01

    The safety of Pajarito Site critical assembly operations depends upon protection built into the facility, upon knowledgeable personnel, and upon good practice as defined by operating procedures and experimental plans. Distance, supplemented by shielding in some cases, would protect personnel against an extreme accident generating 10 19 fissions. During the facility's 28-year history, the direct cost of criticality accidents has translated to a risk of less than $200 per year

  6. GAP Analysis Program (GAP)

    Data.gov (United States)

    Kansas Data Access and Support Center — The Kansas GAP Analysis Land Cover database depicts 43 land cover classes for the state of Kansas. The database was generated using a two-stage hybrid classification...

  7. The Dynamics and Implications of Gap Clearing via Planets in Planetesimal (Debris) Disks

    Science.gov (United States)

    Morrison, Sarah Jane

    Exoplanets and debris disks are examples of solar systems other than our own. As the dusty reservoirs of colliding planetesimals, debris disks provide indicators of planetary system evolution on orbital distance scales beyond those probed by the most prolific exoplanet detection methods, and on timescales 10 r to 10 Gyr. The Solar System possesses both planets and small bodies, and through studying the gravitational interactions between both, we gain insight into the Solar System's past. As we enter the era of resolved observations of debris disks residing around other stars, I add to our theoretical understanding of the dynamical interactions between debris, planets, and combinations thereof. I quantify how single planets clear material in their vicinity and how long this process takes for the entire planetary mass regime. I use these relationships to assess the lowest mass planet that could clear a gap in observed debris disks over the system's lifetime. In the distant outer reaches of gaps in young debris systems, this minimum planet mass can exceed Neptune's. To complement the discoveries of wide-orbit, massive, exoplanets by direct imaging surveys, I assess the dynamical stability of high mass multi-planet systems to estimate how many high mass planets could be packed into young, gapped debris disks. I compare these expectations to the planet detection rates of direct imaging surveys and find that high mass planets are not the primary culprits for forming gaps in young debris disk systems. As an alternative model for forming gaps in planetesimal disks with planets, I assess the efficacy of creating gaps with divergently migrating pairs of planets. I find that migrating planets could produce observed gaps and elude detection. Moreover, the inferred planet masses when neglecting migration for such gaps could be expected to be observable by direct imaging surveys for young, nearby systems. Wide gaps in young systems would likely still require more than two

  8. Size and frequency of gaps in newly synthesized DNA of xeroderma pigmentosum human cells irradiated with ultraviolet light

    International Nuclear Information System (INIS)

    Meneghini, R.; Cordeiro-Stone, M.; Schumacher, R.I.

    1981-01-01

    Native newly synthesized DNA from human cells (xeroderma pigmentosum type) irradiated with ultraviolet light releases short pieces of DNA (L-DNA) when incubated with the single-strand specific S 1 nuclease. This is not observed in the case of unirradiated cells. Previous experiments had shown that the L-DNA resulted from the action of S 1 nuclease upon gaps, i.e., single-stranded DNA discontinuities in larger pieces of double-stranded DNA. We verified that the duplex L-DNA, that arises from the inter-gap regions upon S 1 nuclease treatment, has a size which approximates the distance between two pyrimidine dimers on the same strand. A method was devised to measure the size of the gaps. These parameters have been considered in the proposition of a model for DNA synthesis on a template containing pyrimidine dimers

  9. Defining the Lower Limit of a "Critical Bone Defect" in Open Diaphyseal Tibial Fractures.

    Science.gov (United States)

    Haines, Nikkole M; Lack, William D; Seymour, Rachel B; Bosse, Michael J

    2016-05-01

    To determine healing outcomes of open diaphyseal tibial shaft fractures treated with reamed intramedullary nailing (IMN) with a bone gap of 10-50 mm on ≥50% of the cortical circumference and to better define a "critical bone defect" based on healing outcome. Retrospective cohort study. Forty patients, age 18-65, with open diaphyseal tibial fractures with a bone gap of 10-50 mm on ≥50% of the circumference as measured on standard anteroposterior and lateral postoperative radiographs treated with IMN. IMN of an open diaphyseal tibial fracture with a bone gap. Level-1 trauma center. Healing outcomes, union or nonunion. Forty patients were analyzed. Twenty-one (52.5%) went on to nonunion and nineteen (47.5%) achieved union. Radiographic apparent bone gap (RABG) and infection were the only 2 covariates predicting nonunion outcome (P = 0.046 for infection). The RABG was determined by measuring the bone gap on each cortex and averaging over 4 cortices. Fractures achieving union had a RABG of 12 ± 1 mm versus 20 ± 2 mm in those going on to nonunion (P gaps have a higher probability of nonunion. Research investigating interventions for RABGs should use a predictive threshold for defining a critical bone defect that is associated with greater than 50% risk of nonunion without supplementary treatment. Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

  10. Haptic Discrimination of Distance

    Science.gov (United States)

    van Beek, Femke E.; Bergmann Tiest, Wouter M.; Kappers, Astrid M. L.

    2014-01-01

    While quite some research has focussed on the accuracy of haptic perception of distance, information on the precision of haptic perception of distance is still scarce, particularly regarding distances perceived by making arm movements. In this study, eight conditions were measured to answer four main questions, which are: what is the influence of reference distance, movement axis, perceptual mode (active or passive) and stimulus type on the precision of this kind of distance perception? A discrimination experiment was performed with twelve participants. The participants were presented with two distances, using either a haptic device or a real stimulus. Participants compared the distances by moving their hand from a start to an end position. They were then asked to judge which of the distances was the longer, from which the discrimination threshold was determined for each participant and condition. The precision was influenced by reference distance. No effect of movement axis was found. The precision was higher for active than for passive movements and it was a bit lower for real stimuli than for rendered stimuli, but it was not affected by adding cutaneous information. Overall, the Weber fraction for the active perception of a distance of 25 or 35 cm was about 11% for all cardinal axes. The recorded position data suggest that participants, in order to be able to judge which distance was the longer, tried to produce similar speed profiles in both movements. This knowledge could be useful in the design of haptic devices. PMID:25116638

  11. Haptic discrimination of distance.

    Directory of Open Access Journals (Sweden)

    Femke E van Beek

    Full Text Available While quite some research has focussed on the accuracy of haptic perception of distance, information on the precision of haptic perception of distance is still scarce, particularly regarding distances perceived by making arm movements. In this study, eight conditions were measured to answer four main questions, which are: what is the influence of reference distance, movement axis, perceptual mode (active or passive and stimulus type on the precision of this kind of distance perception? A discrimination experiment was performed with twelve participants. The participants were presented with two distances, using either a haptic device or a real stimulus. Participants compared the distances by moving their hand from a start to an end position. They were then asked to judge which of the distances was the longer, from which the discrimination threshold was determined for each participant and condition. The precision was influenced by reference distance. No effect of movement axis was found. The precision was higher for active than for passive movements and it was a bit lower for real stimuli than for rendered stimuli, but it was not affected by adding cutaneous information. Overall, the Weber fraction for the active perception of a distance of 25 or 35 cm was about 11% for all cardinal axes. The recorded position data suggest that participants, in order to be able to judge which distance was the longer, tried to produce similar speed profiles in both movements. This knowledge could be useful in the design of haptic devices.

  12. Bridging the Gap

    DEFF Research Database (Denmark)

    Kramer Overgaard, Majken; Broeng, Jes; Jensen, Monika Luniewska

    Bridging the Gap (BtG) is a 2-year project funded by The Danish Industry Foundation. The goal of Bridging the Gap has been to create a new innovation model which will increase the rate at which Danish universities can spinout new technology ventures.......Bridging the Gap (BtG) is a 2-year project funded by The Danish Industry Foundation. The goal of Bridging the Gap has been to create a new innovation model which will increase the rate at which Danish universities can spinout new technology ventures....

  13. The Role of the Petite Bourgeoisie within Capitalism: A Response to Pyong Gap Min.

    Science.gov (United States)

    Bonacich, Edna

    1989-01-01

    Presents an argument against Pyong Gap Min's interpretations of the author's views on Korean immigrant entrepreneurship in Los Angeles (California). Addresses the issues of empirical accuracy and policy implications that Min criticized. Discusses differences between Min's approach to social knowledge and her own. (JS)

  14. The influence of tensile strain to critical current of Bi2223 composite tape

    International Nuclear Information System (INIS)

    Mukai, Y.; Shin, J.K.; Ochiai, S.; Okuda, H.; Sugano, M.; Osamura, K.

    2008-01-01

    As the stress-induced damage evolution is different from position to position in the sample, the local critical current is scattered in a sample, affecting on the overall current. The present work aimed to describe the distribution of local critical current and its relation to overall critical current under tensile stress for Bi2223/Ag superconducting composite tape. In the experiment, seven voltage probes were attached in a step of 10 mm. The local critical current and n-value at 77 K under various applied stress levels were measured for a voltage probe distance 10 mm and the overall ones for a probe distance 60 mm. Main results are summarized as follows. The overall critical current and n-value were described well by using the voltage summation model in which the sample was regarded as a one dimensional series circuit. For the low applied stress, the distribution of local critical current was described with the three parameter Weibull distribution function. Using the measured distribution of the local critical current, an experimental relation of critical current to n-value and the voltage summation model, and applying the Monte Carlo method, the overall critical current was predicted, which was in good agreement with the experimental results. Based on these results, the sample length dependence of critical current of the sample damaged by tensile stress was discussed

  15. Development of gap measurement technique in-vessel corium retention using ultrasonic pulse echo method

    International Nuclear Information System (INIS)

    Koo, Kil Mo; Kim, Jong Hwan; Kang, Kyung Ho; Kim, Sang Baik; Sim, Cheul Muu

    1999-03-01

    A gap between a molten material and a lower vessel is formed in the LAVA experiment, a phase 1 study of Sonata-IV program. In this technical report, quantitative results of the gap measurement using an off-line ultrasonic pulse echo method are presented. This report aims at development of an appropriate ultrasonics test method, by analyzing the problems from the external environmental reason and the internal characteristic reason. The signal analyzing methods to improve the S/N ratio in these problems are divided into the time variant synthesized signal analyzing method and the time invariant synthesized signal analyzing method. In this report, the possibility of the application of these two methods to the gap signal and the noise is considered. In this test, the signal of the propagational direction and reflectional direction through solid-liquid-solid specimen was analyzed to understand the behavior of the reflectional signal in a multi-layered structure by filling the gap with water between the melt and the lower head vessel. The quantitative gap measurement using the off-line ultrasonic pulse echo method was available for a little of the scanned region. But furtherly using DSP technique and imaging technique, the better results will be obtained. Some of the measured signals are presented as 2-dimensional spherical mapping method using distance and amplitude. Other signals difficult in quantitative measurement are saved for a new signal processing method. (author). 11 refs., 4 tabs., 54 figs

  16. Technique for estimating relocated gap width for gap conductance calculations

    International Nuclear Information System (INIS)

    Klink, P.H.

    1978-01-01

    Thermally induced fuel fragmentation and relocation has been demonstrated to influence the thermal behavior of a fuel rod in two ways. The effective fuel pellet conductivity is decreased and pellet-to-cladding heat transfer is improved. This paper presents a correlation between as-built and relocated gap width which, used with the Ross and Stoute Gap Conductance Correlation and an appropriate fuel thermal expansion model, closely predicts the measured gap conductances

  17. Teaching For and About Critical Pedagogy in the Post-Secondary Classroom

    Directory of Open Access Journals (Sweden)

    Mary Breunig

    2009-12-01

    Full Text Available While there is a body of literature that considers the theory of critical pedagogy, there is significantly less literature that specifically addresses the ways in which professors attempt to apply this theory in practice. This paper presents the results from a study that was designed, in part, to address this gap. Seventeen self-identified critical pedagogues participated in this qualitative research study. Participants reported their use of the following classroom practices, including: dialogue; group work; co-construction of syllabus; and experiential activities. This paper critically examines the social justice-oriented nature of these critical classroom practices.

  18. Weightless experiments to probe universality of fluid critical behavior

    Science.gov (United States)

    Lecoutre, C.; Guillaument, R.; Marre, S.; Garrabos, Y.; Beysens, D.; Hahn, I.

    2015-06-01

    Near the critical point of fluids, critical opalescence results in light attenuation, or turbidity increase, that can be used to probe the universality of critical behavior. Turbidity measurements in SF6 under weightlessness conditions on board the International Space Station are performed to appraise such behavior in terms of both temperature and density distances from the critical point. Data are obtained in a temperature range, far (1 K) from and extremely close (a few μ K ) to the phase transition, unattainable from previous experiments on Earth. Data are analyzed with renormalization-group matching classical-to-critical crossover models of the universal equation of state. It results that the data in the unexplored region, which is a minute deviant from the critical density value, still show adverse effects for testing the true asymptotic nature of the critical point phenomena.

  19. Bridging the clinician/researcher gap with systemic research: the case for process research, dyadic, and sequential analysis.

    Science.gov (United States)

    Oka, Megan; Whiting, Jason

    2013-01-01

    In Marriage and Family Therapy (MFT), as in many clinical disciplines, concern surfaces about the clinician/researcher gap. This gap includes a lack of accessible, practical research for clinicians. MFT clinical research often borrows from the medical tradition of randomized control trials, which typically use linear methods, or follow procedures distanced from "real-world" therapy. We review traditional research methods and their use in MFT and propose increased use of methods that are more systemic in nature and more applicable to MFTs: process research, dyadic data analysis, and sequential analysis. We will review current research employing these methods, as well as suggestions and directions for further research. © 2013 American Association for Marriage and Family Therapy.

  20. Canopy gap edge determination and the importance of gap edges for plant diversity

    Directory of Open Access Journals (Sweden)

    D. Salvador-Van Eysenrode

    2002-01-01

    Full Text Available Canopy gaps, i.e. openings in the forest cover caused by the fall of structural elements, are considered to be important for the maintenance of diversity and for the forest cycle. A gap can be considered as a young forest patch in the forest matrix, composed of interior surrounded by an edge, both enclosed by a perimeter. Much of the attention has been focused on the gap interior. However, at gap edges the spectrum of regeneration opportunities for plants may be larger than in the interior. Although definitions of gap are still discussed, any definition can describe it in an acceptable way, if justified, but defining edges is complicated and appropriate descriptors should be used. A method to determine gap interior and edge, using light as a descriptor, is presented with an example of gaps from a beech forest (Fagus sylvatica in Belgium. Also, the relevance and implications of gap edges for plant diversity and calculation of forest turnover is discussed.

  1. An updated nuclear criticality slide rule

    International Nuclear Information System (INIS)

    Hopper, C.M.; Broadhead, B.L.

    1998-04-01

    This Volume 2 contains the functional version of the updated nuclear criticality slide rule (more accurately, sliding graphs) that is referenced in An Updated Nuclear Criticality Slide Rule: Technical Basis, NUREG/CR-6504, Vol. 1 (ORNL/TM-13322/V1). This functional slide rule provides a readily usable open-quotes in-handclose quotes method for estimating pertinent nuclear criticality accident information from sliding graphs, thereby permitting (1) the rapid estimation of pertinent criticality accident information without laborious or sophisticated calculations in a nuclear criticality emergency situation, (2) the appraisal of potential fission yields and external personnel radiation exposures for facility safety analyses, and (3) a technical basis for emergency preparedness and training programs at nonreactor nuclear facilities. The slide rule permits the estimation of neutron and gamma dose rates and integrated doses based upon estimated fission yields, distance from the fission source, and time-after criticality accidents for five different critical systems. Another sliding graph permits the estimation of critical solution fission yields based upon fissile material concentration, critical vessel geometry, and solution addition rate. Another graph provides neutron and gamma dose-reduction factors for water, steel, and concrete. Graphs from historic documents are provided as references for estimating critical parameters of various fissile material systems. Conversion factors for various English and metric units are provided for quick reference

  2. Distance Students’ Readiness for Social Media and Collaboration

    Directory of Open Access Journals (Sweden)

    Bruno Poellhuber

    2011-10-01

    Full Text Available In recent years, there has been a rapid growth in the use of social networking tools (e.g., Facebook and social media in general, mainly for social, recreational, and entertainment purposes (Smith, Salaway, & Caruso, 2009. Many educators believe that these tools offer new educational affordances and avenues for students to interact with each other and with their teachers or tutors. Considering the traditional dropout rate problem documented in distance courses (Rovai, 2003; Woodley, 2004, these tools may be of special interest for distance education institutions as they have the potential to assist in the critical “social integration” associated with persistence (Sweet, 1986; Tinto, 1975. However, as distance students are typically older than regular on-campus students (Bean & Metzner, 1985; Rovai, 2003, little is known about their expertise with social media or their interest in harnessing these tools for informal learning or collaborating with peers.To investigate these issues, an online questionnaire was distributed to students from four large Canadian distance education institutions. A systematic sampling procedure led to 3,462 completed questionnaires. The results show that students have diverse views and experiences, but they also show strong and significant age and gender differences in a variety of measures, as well as an important institution effect on the student’s interest in collaboration. Males and younger students scored higher on almost all indicators (past teamwork experience, cooperative preferences, attitudes toward technology, experience with social software, etc.. These age and gender differences should be interpreted cautiously, however, as they are based on self-reported measures. The limits of the study, as well as future developments and research questions, are outlined.

  3. Updated tool for nuclear criticality accident emergency response

    International Nuclear Information System (INIS)

    Broadhead, B.L.; Hopper, C.M.

    1995-01-01

    Some 20 yr ago a hand-held slide rule was developed at the Oak Ridge Y-12 Plant to aid in the response to several postulated nuclear criticality accidents. These assumed accidents involved highly enriched uranium in either a bare metal or a uranyl nitrate system. The slide rule consisted of a sliding scale based on the total fission yield and four corresponding dose indicators: (1) a prompt radiation dose relationship as a function of distance; (2) a delayed fission product gamma dose rate relationship as a function of time and distance; (3) the total dose relationship with time and distance; and (4) the I-min integrated dose relationship with time and distance. The original slide rule was generated assuming very simplistic numerical procedures such as the inverse-square relationship of dose with distance and the Way-Wigner relationship to express the time dependence of the dose. The simple prescriptions were tied to actual dose measurements from similar systems to yield a meaningful, yet simple approach to emergency planning and response needs. This paper describes the application of an advanced procedure to the updating of the original slide rule for five critical systems. These five systems include (a) an unreflected sphere of 93.2 wt% enriched uranium metal, (b) an unreflected sphere of 93.2 wt% enriched uranyl nitrate solution with a H/ 235 U ratio of 500, (c) an unreflected sphere of damp 93.2 wt% enriched uranium oxide with a H/ 235 U ratio of 10, (d) an unreflected sphere of 4.95 wt% enriched uranyl fluoride solution having a H/ 235 U ratio of 410, and (e) an unreflected sphere of damp 5 wt% enriched uranium dioxide having a H/ 235 U ratio of 200

  4. Power-sharing: concepts, debates and gaps

    Directory of Open Access Journals (Sweden)

    Alexandre de Sousa Carvalho

    2016-05-01

    Full Text Available Academic literature tends to reflect the two main objectives of power-sharing: promoting the construction of sustainable peace and serving to structure the foundations for growth and development of democracy in divided societies. reflecting this, two dimensions and discourses of analysis and evaluation stand out: a classical dimension centred on power-sharing as theory and a normative proposal for democracy in divided societies, and another focused mainly on power-sharing as a meachanism of conflict management. This article aims to introduce the reader to discussions about power-sharing, reviewing and critically analysing power-sharing literature to show its gaps and tensions, as well as suggesting some points where one can continue the debate.

  5. Numerical difficulties to obtain 3-d critical exponents from platonic solids

    International Nuclear Information System (INIS)

    Alcaraz, F.C.; Herrmann, H.J.

    1985-01-01

    The possibility to extract critical exponents of 3-d systems exploring the mass gap amplitudes of platonic solids is tested. For the Ising model the proposed method does not work for numerical reasons. (Author) [pt

  6. Channel-accelerating gap interaction and beam acceleration and transport experiments with the recirculating linear accelerator (RLA)

    International Nuclear Information System (INIS)

    Mazarakis, M.G.; Smith, D.L.; Poukey, J.W.; Wagner, J.S.; Bennett, L.F.; Olson, W.R.; Turman, B.N.; Prestwich, K.R.; Wells, J.; Struve, K.

    1992-01-01

    The lifetime of the Ion Focusing Regime (IFR) channel following the pulsing of the post-accelerating gaps is critical for open-ended low energy devices. It dictates the number of allowable beam recirculations through the gaps. In the case of a closed racetrack configuration, it is significant but not as critical, since the presence of the electron beam focuses the ions and lengthens the lifetime of the ion channel. The authors have experimentally established that pulsing an accelerating gap perturbs the IFR channel. However for the parameters studied, the lifetime is long enough to allow at least four beam recirculations in a spiral device. In addition transparent grids of cusp fields positioned upstream and downstream from the gaps prevent them from perturbing the IFR channel. Experiments were performed with and without injected electron beams. For the experiments investigating the IFR channel interaction with the accelerating gap, the injector was removed and the beam line was extended downstream and upstream from the accelerating cavity. Only the first straight section of the RLA with one accelerating cavity (ET-2) was utilized. The acceleration and transport experiments were performed utilizing two injectors: first the low energy 1.3-MV Isolated Blumlein (IB) injector and most recently the new 4-MV 20-kA injector. Beams of 6--20 kA current were produced and successfully transported and accelerated through the ET-2 post-accelerating gap. For both injectors an apertured non-immersed ion-focused foilless diode was selected among various options. It is the simplest and easiest to operate and can be adjusted to provide variable beam impedance loads to the injector. The transport efficiencies were 90% for the low energy injector and 100% for the new 4-MV injector. The beam Gaussian profile and radius (5 mm) remain the same through acceleration. Experimental results will be presented and compared with numerical simulations

  7. Thermodynamic parameters of single- or multi-band superconductors derived from self-field critical currents

    Energy Technology Data Exchange (ETDEWEB)

    Talantsev, Evgueni [Robinson Research Institute, Victoria University of Wellington, Lower Hutt (New Zealand); Crump, Wayne P.; Tallon, Jeffery L. [Robinson Research Institute, Victoria University of Wellington, Lower Hutt (New Zealand); MacDiarmid Institute for Advanced Materials and Nanotechnology, Lower Hutt (New Zealand)

    2017-12-15

    Key questions for any superconductor include: what is its maximum dissipation-free electrical current (its 'critical current') and can this be used to extract fundamental thermodynamic parameters? Present models focus on depinning of magnetic vortices and implicate materials engineering to maximise pinning performance. But recently we showed that the self-field critical current for thin films is a universal property, independent of microstructure, controlled only by the penetration depth. Here, using an extended BCS-like model, we calculate the penetration depth from the temperature dependence of the superconducting energy gap thus allowing us to fit self-field critical current data. In this way we extract from the T-dependent gap a set of key thermodynamic parameters, the ground-state penetration depth, energy gap and jump in electronic specific heat. Our fits to 79 available data sets, from zinc nanowires to compressed sulphur hydride with critical temperatures of 0.65 to 203 K, respectively, are excellent and the extracted parameters agree well with reported bulk values. Samples include thin films, wires or nanowires of single- or multi-band s-wave and d-wave superconductors of either type I or type II. For multiband or multiphase samples we accurately recover individual band contributions and phase fractions. (copyright 2017 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  8. An impurity-induced gap system as a quantum data bus for quantum state transfer

    International Nuclear Information System (INIS)

    Chen, Bing; Li, Yong; Song, Z.; Sun, C.-P.

    2014-01-01

    We introduce a tight-binding chain with a single impurity to act as a quantum data bus for perfect quantum state transfer. Our proposal is based on the weak coupling limit of the two outermost quantum dots to the data bus, which is a gapped system induced by the impurity. By connecting two quantum dots to two sites of the data bus, the system can accomplish a high-fidelity and long-distance quantum state transfer. Numerical simulations for finite system show that the numerical and analytical results of the effective coupling strength agree well with each other. Moreover, we study the robustness of this quantum communication protocol in the presence of disorder in the couplings between the nearest-neighbor quantum dots. We find that the gap of the system plays an important role in robust quantum state transfer

  9. Dosimetric comparison between proton and photon beams in the moving gap region in cranio-spinal irradiation (CSI)

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Chee-Wai; Das, Indra J.; Zhao, Li; Wolanski, Mark; Johnstone, Peter A.S.; Buchsbaum, Jeffrey C. [IU Health Proton Therapy Center, Bloomington (United States); Dept. of Radiation Oncology, Indiana Univ. School of Medicine, Indianapolis (United States)], e-mail: ccheng1@iuhealth.org; Srivastava, Shiv P. [Dept. of Radiation Oncology, Indiana Univ. School of Medicine, Indianapolis (United States); Dept. of Radiation Oncology, Reid Hospital, Richmond (United States); Simmons, Joseph [IU Health Proton Therapy Center, Bloomington (United States)

    2013-04-15

    Purpose: To investigate the moving gap region dosimetry in proton beam cranio-spinal irradiation (CSI) to provide optimal dose uniformity across the treatment volume. Material and methods: Proton beams of ranges 11.6 cm and 16 cm are used for the spine and the brain fields, respectively. Beam profiles for a 30 cm snout are first matched at the 50% level (hot match) on the computer. Feathering is simulated by shifting the dose profiles by a known distance two successive times to simulate a 2 x feathering scheme. The process is repeated for 2 mm and 4 mm gaps. Similar procedures are used to determine the dose profiles in the moving gap for a series of gap widths, 0-10 mm, and feathering step sizes, 4-10 mm, for a Varian iX 6MV beam. The proton and photon dose profiles in the moving gap region are compared. Results: The dose profiles in the moving gap exhibit valleys and peaks in both proton and photon beam CSI. The dose in the moving gap for protons is around 100% or higher for 0 mm gap, for both 5 and 10 mm feathering step sizes. When the field gap is comparable or larger than the penumbra, dose minima as low as 66% is obtained. The dosimetric characteristics for 6 MV photon beams can be made similar to those of the protons by appropriately combining gap width and feathering step size. Conclusion: The dose in the moving gap region is determined by the lateral penumbras, the width of the gap and the feathering step size. The dose decreases with increasing gap width or decreasing feathering step size. The dosimetric characteristics are similar for photon and proton beams. However, proton CSI has virtually no exit dose and is beneficial for pediatric patients, whereas with photon beams the whole lung and abdomen receive non-negligible exit dose.

  10. A comparison of the wide gap and narrow gap resistive plate chamber

    International Nuclear Information System (INIS)

    Cerron Zeballos, E.; Crotty, I.; Hatzifotiadou, D.; Valverde, J.L.; Neupane, S.; Peskov, V.; Singh, S.; Williams, M.C.S.; Zichichi, A.

    1996-01-01

    In this paper we study the performance of a wide gap RPC and compare it with that of a narrow gap RPC, both operated in avalanche mode. We have studied the total charge produced in the avalanche. We have measured the dependence of the performance with rate. In addition we have considered the effect of the tolerance of gas gap and calculated the power dissipated in these two types of RPC. We find that the narrow gap RPC has better timing ability; however the wide gap has superior rate capability, lower power dissipation in the gas volume and can be constructed with less stringent mechanical tolerances. (orig.)

  11. A comparison of the wide gap and narrow gap resistive plate chamber

    CERN Document Server

    Cerron-Zeballos, E; Hatzifotiadou, D; Lamas-Valverde, J; Neupane, S; Peskov, Vladimir; Singh, S; Williams, M C S; Zichichi, Antonino

    1996-01-01

    In this paper we study the performance of a wide gap RPC and compare it with that of a narrow gap RPC, both operated in avalanche mode. We have studied the total charge produced in the avalanche. We have measured the dependence of the performance with rate. In addition we have considered the effect of the tolerance of gas gap and calculated the power dissipated in these two types of RPC. We find that the narrow gap RPC has better timing ability; however the wide gap has superior rate capability, lower power dissipation in the gas volume and can be constructed with less stringent mechanical tolerances.

  12. Distance Education: the humanization of technology in a Freirean perspective

    Science.gov (United States)

    Ferreira, Orlando Rodrigues; Voelzke, Marcos Rincon

    2014-05-01

    The Distance Education [DE] presents significant growth in graduates and postgraduates programs. Regarding this fact, new challenges arise and others must be considered, as the generation gap between digital immigrants and digital natives, the establishment of a population increasingly accustomed to Information and Communication Technologies [ICT] and teaching methodologies that should be used and developed. Vygotsky's model of social interaction related to mediation can and should be used in DE, and concerning historical, social and cultural approaches affecting Brazilian reality, Paulo Freire is still up-to-date, integrating humanization into the use of ICT. This work only proceeds with analyzes of these elements, being an excerpt of the master's dissertation of one of the authors [Ferreira], under the guidance of another [Voelzke].

  13. Ultrasonic measurement of gap between calandria tube and liquid injection shutdown system tube in PHWR

    International Nuclear Information System (INIS)

    Kim, Tae Ryong; Sohn, Seok Man; Lee, Jun Shin; Lee, Sun Ki; Lee, Jong Po

    2001-01-01

    Sag of CT or liquid injection shutdown system tubes in pressurized heavy water reactor is known to occur due to irradiation creep and growth during plant operation. When the sag of CT is big enough, the CT tube possibly comes in contact with liquid injection shutdown system tube (LIN) crossing beneath the CT, which subsequently may prevent the safe operation. It is therefore necessary to check the gap between the two tubes in order to confirm no contacts when using a proper measure periodically during the plant life. An ultrasonic gap measuring probe assembly which can be fed through viewing port installed on the calandria was developed and utilized to measure the sags of both tubes in a pressurized heavy water reactor in Korea. It was found that the centerlines of CT and LIN can be precisely detected by ultrasonic wave. The gaps between two tubes were easily obtained from the relative distance of the measured centerline elevations of the tubes. But the measured gap data observed at the viewing port were actually not the data at the crossing point of CT and LIN. To get the actual gap between two tubes, mathematical modeling for the deflection curves of two tubes was used. The sags of CT and LIN tubes were also obtained by comparison of the present centerlines with the initial elevations at the beginning of plant operation. The gaps between two tubes in the unmeasurable regions were calculated based on the measurement data and the channel power distribution

  14. A Critical Examination of the Teaching Methodologies Pertaining to Distance Learning in Geographic Education: Andragogy in an Adult Online Certificate Program

    Science.gov (United States)

    Schultz, Richard B.

    2012-01-01

    Differences between student audiences are an important aspect not only of traditional learning in higher education, but also in the distance learning environment. Facilitators of distance learning coursework must be cognizant of the differences which adult students bring to the classroom and their varying expectations and reasons for learning.…

  15. Demographic characteristics in patients with short-gap and long-gap ...

    African Journals Online (AJOL)

    Further analysis of this topic is warranted ... Keywords: demographic characteristics, long-gap esophageal atresia, short-gap ... Thus, we conducted the present study to analyze the character- ..... this issue, providing fundamental information.

  16. The 0.5-2.22 micrometer Scattered Light Spectrum of the Disk around TW Hya: Detection of a Partially Filled Disk Gap at 80 AU*

    Science.gov (United States)

    Debes, John H.; Jang-Condell, Hannah; Weinberger, Alycia J.; Roberge, Aki; Schneider, Glenn

    2013-01-01

    We present a 0.5-2.2 micrometer scattered light spectrum of the circumstellar disk around TW Hya from a combination of spatially resolved Hubble Space Telescope STIS spectroscopy and NICMOS coronagraphic images of the disk. We investigate the morphology of the disk at distances greater than 40 AU over this wide range of wavelengths, and identify the presence of a depression in surface brightness at approximately 80 AU that could be caused by a gap in the disk. Additionally, we quantify the surface brightness, azimuthal symmetry, and spectral character of the disk as a function of radius. Our analysis shows that the scattering efficiency of the dust is largely neutral to blue over the observed wavelengths. We model the disk as a steady a-disk with an ad hoc gap structure. The thermal properties of the disk are selfconsistently calculated using a three-dimensional radiative transfer code that uses ray tracing to model the heating of the disk interior and scattered light images. We find a good fit to the data over a wide range of distances from the star if we use a model disk with a partially filled gap of 30% depth at 80 AU and with a self-similar truncation knee at 100 AU. The origin of the gap is unclear, but it could arise from a transition in the nature of the disk's dust composition or the presence of a planetary companion. Based on scalings to previous hydrodynamic simulations of gap-opening criteria for embedded proto-planets, we estimate that a planetary companion forming the gap could have a mass between 6 and 28 solar mass.

  17. Distancing from experienced self: how global-versus-local perception affects estimation of psychological distance.

    Science.gov (United States)

    Liberman, Nira; Förster, Jens

    2009-08-01

    In 4 studies, the authors examined the prediction derived from construal level theory (CLT) that higher level of perceptual construal would enhance estimated egocentric psychological distance. The authors primed participants with global perception, local perception, or both (the control condition). Relative to the control condition, global processing made participants estimate larger psychological distances in time (Study 1), space (Study 2), social distance (Study 3), and hypotheticality (Study 4). Local processing had the opposite effect. Consistent with CLT, all studies show that the effect of global-versus-local processing did emerge when participants estimated egocentric distances, which are distances from the experienced self in the here and now, but did not emerge with temporal distances not from now (Study 1), spatial distances not from here (Study 2), social distances not from the self (Study 3), or hypothetical events that did not involve altering an experienced reality (Study 4).

  18. Fast Computing for Distance Covariance

    OpenAIRE

    Huo, Xiaoming; Szekely, Gabor J.

    2014-01-01

    Distance covariance and distance correlation have been widely adopted in measuring dependence of a pair of random variables or random vectors. If the computation of distance covariance and distance correlation is implemented directly accordingly to its definition then its computational complexity is O($n^2$) which is a disadvantage compared to other faster methods. In this paper we show that the computation of distance covariance and distance correlation of real valued random variables can be...

  19. ORDERED WEIGHTED DISTANCE MEASURE

    Institute of Scientific and Technical Information of China (English)

    Zeshui XU; Jian CHEN

    2008-01-01

    The aim of this paper is to develop an ordered weighted distance (OWD) measure, which is thegeneralization of some widely used distance measures, including the normalized Hamming distance, the normalized Euclidean distance, the normalized geometric distance, the max distance, the median distance and the min distance, etc. Moreover, the ordered weighted averaging operator, the generalized ordered weighted aggregation operator, the ordered weighted geometric operator, the averaging operator, the geometric mean operator, the ordered weighted square root operator, the square root operator, the max operator, the median operator and the min operator axe also the special cases of the OWD measure. Some methods depending on the input arguments are given to determine the weights associated with the OWD measure. The prominent characteristic of the OWD measure is that it can relieve (or intensify) the influence of unduly large or unduly small deviations on the aggregation results by assigning them low (or high) weights. This desirable characteristic makes the OWD measure very suitable to be used in many actual fields, including group decision making, medical diagnosis, data mining, and pattern recognition, etc. Finally, based on the OWD measure, we develop a group decision making approach, and illustrate it with a numerical example.

  20. Experimental Study on Branch and Diffuse Type of Streamers in Leader Restrike of Long Air Gap Discharge

    International Nuclear Information System (INIS)

    Chen She; Zeng Rong; Zhuang Chijie; Zhou Xuan; Ding Yujian

    2016-01-01

    One of the main problems in the Ultra High Voltage (UHV) transmission project is to choose the external insulation distance, which requires a deep understanding of the long air gap discharge mechanism. The leader-streamer propagation is one of most important stages in long air gap discharge. In the conductor-tower lattice configuration, we have measured the voltage, the current on the high voltage side and the electric field in the gap. While the streamer in the leader-streamer system presented a conical or hyperboloid diffuse shape, the clear branch structure streamer in front of the leader was firstly observed by a high speed camera in the experiment. Besides, it is found that the leader velocity, width and injected charge for the branch type streamer are greater than those of a diffuse type. We propose that the phenomenon results from the high humidity, which was 15.5-16.5 g/m 3 in our experiment. (paper)

  1. Spin Orbit Coupling Gap and Indirect Gap in Strain-Tuned Topological Insulator-Antimonene

    OpenAIRE

    Cheung, Chi-Ho; Fuh, Huei-Ru; Hsu, Ming-Chien; Lin, Yeu-Chung; Chang, Ching-Ray

    2016-01-01

    Recently, searching large-bulk band gap topological insulator (TI) is under intensive study. Through k?P theory and first-principles calculations analysis on antimonene, we find that ?-phase antimonene can be tuned to a 2D TI under an in-plane anisotropic strain and the magnitude of direct bulk band gap (SOC gap) depends on the strength of spin-orbit coupling (SOC) which is strain-dependent. As the band inversion of this TI accompanies with an indirect band gap, the TI bulk band gap is the in...

  2. Band gap engineering of MoS{sub 2} upon compression

    Energy Technology Data Exchange (ETDEWEB)

    López-Suárez, Miquel, E-mail: miquel.lopez@nipslab.org [NiPS Laboratory, Dipartimento di Fisica e Geologia, Università degli Studi di Perugia, 06123 Perugia (Italy); Neri, Igor [NiPS Laboratory, Dipartimento di Fisica e Geologia, Università degli Studi di Perugia, 06123 Perugia (Italy); INFN Sezione di Perugia, via Pascoli, 06123 Perugia (Italy); Rurali, Riccardo [Institut de Ciència de Materials de Barcelona (ICMAB–CSIC) Campus de Bellaterra, 08193 Bellaterra, Barcelona (Spain)

    2016-04-28

    Molybdenum disulfide (MoS{sub 2}) is a promising candidate for 2D nanoelectronic devices, which shows a direct band-gap for monolayer structure. In this work we study the electronic structure of MoS{sub 2} upon both compressive and tensile strains with first-principles density-functional calculations for different number of layers. The results show that the band-gap can be engineered for experimentally attainable strains (i.e., ±0.15). However, compressive strain can result in bucking that can prevent the use of large compressive strain. We then studied the stability of the compression, calculating the critical strain that results in the on-set of buckling for free-standing nanoribbons of different lengths. The results demonstrate that short structures, or few-layer MoS{sub 2}, show semi-conductor to metal transition upon compressive strain without bucking.

  3. Critical phases in the raise and peel model

    Science.gov (United States)

    Jara, D. A. C.; Alcaraz, F. C.

    2018-05-01

    The raise and peel model (RPM) is a nonlocal stochastic model describing the space and time fluctuations of an evolving one dimensional interface. Its relevant parameter u is the ratio between the rates of local adsorption and nonlocal desorption processes (avalanches) The model at u  =  1 is the first example of a conformally invariant stochastic model. For small values u    u 0 it is critical. Although previous studies indicate that u 0  =  1, a determination of u 0 with a reasonable precision is still missing. By calculating numerically the structure function of the height profiles in the reciprocal space we confirm with good precision that indeed u 0  =  1. We establish that at the conformal invariant point u  =  1 the RPM has a roughening transition with dynamical and roughness critical exponents z  =  1 and , respectively. For u  >  1 the model is critical with a u-dependent dynamical critical exponent that tends towards zero as . However at 1/u  =  0 the RPM is exactly mapped into the totally asymmetric exclusion problem. This last model is known to be noncritical (critical) for open (periodic) boundary conditions. Our numerical studies indicate that the RPM as , due to its nonlocal dynamical processes, has the same large-distance physics no matter what boundary condition we chose. For u  >  1, our numerical analysis shows that in contrast to previous predictions, the region is composed of two distinct critical phases. For the height profiles are rough (), and for the height profiles are flat at large distances (). We also observed that in both critical phases (u  >  1) the RPM at short length scales, has an effective behavior in the Kardar–Parisi–Zhang critical universality class, that is not the true behavior of the system at large length scales.

  4. A study on suppressing transmittance fluctuations for air-gapped Glan-type polarizing prisms

    Science.gov (United States)

    Zhang, Chuanfa; Li, Dailin; Zhu, Huafeng; Li, Chuanzhi; Jiao, Zhiyong; Wang, Ning; Xu, Zhaopeng; Wang, Xiumin; Song, Lianke

    2018-05-01

    Light intensity transmittance is a key parameter for the design of polarizing prisms, while sometimes its experimental curves based on spatial incident angle presents periodical fluctuations. Here, we propose a novel method for completely suppressing these fluctuations via setting a glued error angle in the air gap of Glan-Taylor prisms. The proposal consists of: an accurate formula of the intensity transmittance for Glan-Taylor prisms, a numerical simulation and a contrast experiment of Glan-Taylor prisms for analyzing the causes of the fluctuations, and a simple method for accurately measuring the glued error angle. The result indicates that when the setting glued error angle is larger than the critical angle for a certain polarizing prism, the fluctuations can be completely suppressed, and a smooth intensity transmittance curve can be obtained. Besides, the critical angle in the air gap for suppressing the fluctuations is decreased with the increase of beam spot size. This method has the advantage of having less demand for the prism position in optical systems.

  5. Self-organized Criticality in a Modified Evolution Model on Generalized Barabasi-Albert Scale-Free Networks

    International Nuclear Information System (INIS)

    Lin Min; Wang Gang; Chen Tianlun

    2007-01-01

    A modified evolution model of self-organized criticality on generalized Barabasi-Albert (GBA) scale-free networks is investigated. In our model, we find that spatial and temporal correlations exhibit critical behaviors. More importantly, these critical behaviors change with the parameter b, which weights the distance in comparison with the degree in the GBA network evolution.

  6. CFD simulation of estimating critical shear stress for cleaning flat ...

    Indian Academy of Sciences (India)

    Sumit Kawale

    2017-11-22

    Nov 22, 2017 ... Jet impingement; wall shear stress; cleaning of flat plate; turbulence model; critical shear stress; ... On comparing the theoretical predictions with wall shear ... distance and Reynolds number on peak value of local shear stress ...

  7. Energy gap in S- and D-wave pairing superconductors

    International Nuclear Information System (INIS)

    Dolgov, O.V.; Golubov, A.A.

    1988-01-01

    In this paper the ratio of 2Δ g /T c , where Δ g is the gap edge, T c is the critical temperature, is calculated in the framework of the model of strong electron-phonon coupling. Both isotropic and anisotropic pairing cases are considered. It is shown that the isotropic Eliashberg model can not account for the large values of the ratio 2Δ g /T c for the reasonable values of the electron-phonon coupling parameter λ while anisotropic pairing can resolve this problem

  8. Spatial consequences of bridging the saccadic gap

    DEFF Research Database (Denmark)

    Yarrow, Kielan; Whiteley, Louise Emma; Rothwell, John C

    2006-01-01

    with the post-saccadic image. We first demonstrate that this illusion holds for moving objects, implying that the perception of time, velocity, and distance traveled become discrepant. We then show that this discrepancy is partially resolved up to 500 ms after a saccade: the perceived offset position of a post......We report six experiments suggesting that conscious perception is actively redrafted to take account of events both before and after the event that is reported. When observers saccade to a stationary object they overestimate its duration, as if the brain were filling in the saccadic gap......-saccadic moving stimulus shows a greater forward mislocalization when pursued after a saccade than during pursuit alone. These data are consistent with the idea that the temporal bias is resolved by the subsequent spatial adjustment to provide a percept that is coherent in its gist but inconsistent in its detail....

  9. Critical neuroscience—or critical science? A perspective on the perceived normative significance of neuroscience

    Science.gov (United States)

    Schleim, Stephan

    2014-01-01

    Members of the Critical Neuroscience initiative raised the question whether the perceived normative significance of neuroscience is justified by the discipline’s actual possibilities. In this paper I show how brain research was assigned the ultimate political, social, and moral authority by some leading researchers who suggested that neuroscientists should change their research priorities, promising solutions to social challenges in order to increase research funds. Discussing the two examples of cognitive enhancement and the neuroscience of (im)moral behavior I argue that there is indeed a gap between promises and expectations on the one hand and knowledge and applications on the other. However it would be premature to generalize this to the neurosciences at large, whose knowledge-producing, innovative, and economic potentials have just recently been confirmed by political and scientific decision-makers with the financial support for the Human Brain Project and the BRAIN Initiative. Finally, I discuss two explanations for the analyzed communication patterns and argue why Critical Neuroscience is necessary, but not sufficient. A more general Critical Science movement is required to improve the scientific incentive system. PMID:24904376

  10. The Communication Skills of Accountants: What We Know and the Gaps in Our Knowledge

    Science.gov (United States)

    Siriwardane, Harshini P.; Durden, Chris H.

    2014-01-01

    This paper critically reviews 19 studies published between 1972 and 2012 that investigated the written and/or oral communication skills of practicing accountants. The core aim of the review was to identify skills considered important and highlight gaps regarding what is known about existing and desired communication skills in the accounting…

  11. Specific heat of Nb{sub 3}Sn: The case for a single gap

    Energy Technology Data Exchange (ETDEWEB)

    Jo, Y. J., E-mail: jophy@knu.ac.kr [Department of Physics, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Zhou, Jian; Sung, Zu Hawn; Lee, Peter J.; Larbalestier, D. C. [National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310 (United States)

    2014-10-01

    The important influence of multiple gaps in the superconductivity of MgB{sub 2} and Fe-based compounds, especially because of the possibility that manipulation of a second gap can significantly raise the upper critical field H{sub c2}, has refocused attention on Nb{sub 3}Sn because anomalies in both specific heat and point-contact tunneling studies have led to the proposal that Nb{sub 3}Sn is also a two-gap superconductor. Here, we search for evidence of the second gap in a careful study of the influence of the homogenization temperature on the sample uniformity. We show that it is very difficult to fabricate samples that are both homogeneous and stoichiometric. We find so-called “second-gap” anomalies disappear only after high temperature and long-term annealing. Such a well-annealed sample shows only a strong, electron-phonon-coupled, single-gap behavior. In contrast, samples reacted and annealed at lower temperatures, as in the earlier two-gap studies, show small chemical composition variations of the A15 phase. We propose that the second gap sightings are actually due to variation of T{sub c} within very difficult-to-fully homogenize samples. A curiosity of the A15 Nb{sub 3}Sn phase is that almost any mixture of Nb and Sn tries to form a stoichiometric A15 composition, but the residue of course contains off-stoichiometric A15, Nb, and other phases when the Nb:Sn ratio departs from the true 3:1 stoichiometry.

  12. Distance Education and Open Learning in Sub-Saharan Africa: Criteria and Conditions for Quality and Critical Success Factor-- Working Group on Distance Education and Open Learning. A Survey of Policy and Practice. Final Report

    Science.gov (United States)

    Commonwealth of Learning, 2004

    2004-01-01

    Both of these "Surveys of policy and practice" were conducted on behalf of COL by the South African Institute for Distance Education (SAIDE) as part of COL's partnership agreement with the Association for the Development of Education in Africa (ADEA) Working Group on Distance Education and Open Learning. The first report identifies…

  13. Low genetic diversity and strong population structure shaped by anthropogenic habitat fragmentation in a critically endangered primate, Trachypithecus leucocephalus.

    Science.gov (United States)

    Wang, W; Qiao, Y; Li, S; Pan, W; Yao, M

    2017-06-01

    Habitat fragmentation may strongly impact population genetic structure and reduce the genetic diversity and viability of small and isolated populations. The white-headed langur (Trachypithecus leucocephalus) is a critically endangered primate species living in a highly fragmented and human-modified habitat in southern China. We examined the population genetic structure and genetic diversity of the species and investigated the environmental and anthropogenic factors that may have shaped its population structure. We used 214 unique multi-locus genotypes from 41 social groups across the main distribution area of T. leucocephalus, and found strong genetic structure and significant genetic differentiation among local populations. Our landscape genetic analyses using a causal modelling framework suggest that a large habitat gap and geographical distance represent the primary landscape elements shaping genetic structure, yet high levels of genetic differentiation also exist between patches separated by a small habitat gap or road. This is the first comprehensive study that has evaluated the population genetic structure and diversity of T. leucocephalus using nuclear markers. Our results indicate strong negative impacts of anthropogenic land modifications and habitat fragmentation on primate genetic connectivity between forest patches. Our analyses suggest that two management units of the species could be defined, and indicate that habitat continuity should be enforced and restored to reduce genetic isolation and enhance population viability.

  14. Is there a gap in the gap? Regional differences in the gender pay gap

    OpenAIRE

    Hirsch, Boris; König, Marion; Möller, Joachim

    2009-01-01

    In this paper, we investigate regional differences in the gender pay gap both theoretically and empirically. Within a spatial oligopsony model, we show that more densely populated labour markets are more competitive and constrain employers' ability to discriminate against women. Utilising a large administrative data set for western Germany and a flexible semi-parametric propensity score matching approach, we find that the unexplained gender pay gap for young workers is substantially lower in ...

  15. Literary Translation as a Tool for Critical Language Planning

    Science.gov (United States)

    Mooneeram, Roshni

    2013-01-01

    This paper argues that Dev Virahsawmy, an author who manipulates literary translation for the purposes of linguistic prestige formation and re-negotiation, is a critical language-policy practitioner, as his work fills an important gap in language planning scholarship. A micro-analysis of the translation of a Shakespearean sonnet into Mauritian…

  16. Design of ultra compact polarization splitter based on complete photonic band gap

    Science.gov (United States)

    Sinha, R. K.; Nagpal, Yogita

    2005-11-01

    Certain select structures in photonic crystals (PhCs) exhibit complete photonic band gap i.e. a frequency region where the photonic band gaps for both polarizations (i.e. transverse electric and transverse magnetic modes) exist and overlap. One of the most fundamental applications of the photonic band gap structures is the design of photonic crystal waveguides, which can be made by inserting linear defects in the photonic crystal structures. By setting closely two parallel 2D PhC waveguides, a directional waveguide coupler can be designed, which can be used to design a polarization splitter. In this paper we design a polarization splitter in a photonic crystal structure composed of two dimensional honeycomb pattern of dielectric rods in air. This photonic crystal structure exhibits a complete photonic band gap that extends from λ = 1.49 μm to λ = 1.61 μm, where lambda is the wavelength in free space, providing a large bandwidth of 120 nm. A polarization splitter can be made by designing a polarization selective coupler. The coupling lengths at various wavelengths for both polarizations have been calculated using the Finite Difference Time Domain method. It has been shown that the coupling length, for TE polarization is much smaller as compared to that for the TM polarization. This principle is used to design a polarization splitter of length 32 μm at λ = 1.55 μm. Further, the spectral response of the extinction ratios for both polarizations in the two waveguides at propagation distance of 32 μm has been studied.

  17. EMPOWERING THE HUMAN RESOURCES AND THE ROLE OF DISTANCE LEARNING

    Directory of Open Access Journals (Sweden)

    Sukmaya LAMA

    2012-07-01

    Full Text Available As the world is invaded by technological inventions and wonders, life becoming more fast and crazy, yet there can be no doubt that the critical factor for the development of a nation or a state is its human resource. The productivity of a nation is influenced by the number of its skilled population. When we look into the problem of underdevelopment from human resource perspective we are bound to take a look at the educational scenario. In India, the higher education scenario has been very sickly, due to the pro profit policies, lack of infrastructure, entry of private players, etc. The growth of distance education phenomenon in India has no doubt brought a ray of hope. The present paper aims to look into the role of distance education in Assam and the potential it carries in building a huge wealth of human resources.

  18. THE 0.5-2.22 μm SCATTERED LIGHT SPECTRUM OF THE DISK AROUND TW Hya: DETECTION OF A PARTIALLY FILLED DISK GAP AT 80 AU

    International Nuclear Information System (INIS)

    Debes, John H.; Jang-Condell, Hannah; Weinberger, Alycia J.; Roberge, Aki; Schneider, Glenn

    2013-01-01

    We present a 0.5-2.2 μm scattered light spectrum of the circumstellar disk around TW Hya from a combination of spatially resolved Hubble Space Telescope STIS spectroscopy and NICMOS coronagraphic images of the disk. We investigate the morphology of the disk at distances >40 AU over this wide range of wavelengths, and identify the presence of a depression in surface brightness at ∼80 AU that could be caused by a gap in the disk. Additionally, we quantify the surface brightness, azimuthal symmetry, and spectral character of the disk as a function of radius. Our analysis shows that the scattering efficiency of the dust is largely neutral to blue over the observed wavelengths. We model the disk as a steady α-disk with an ad hoc gap structure. The thermal properties of the disk are self-consistently calculated using a three-dimensional radiative transfer code that uses ray tracing to model the heating of the disk interior and scattered light images. We find a good fit to the data over a wide range of distances from the star if we use a model disk with a partially filled gap of 30% depth at 80 AU and with a self-similar truncation knee at 100 AU. The origin of the gap is unclear, but it could arise from a transition in the nature of the disk's dust composition or the presence of a planetary companion. Based on scalings to previous hydrodynamic simulations of gap-opening criteria for embedded proto-planets, we estimate that a planetary companion forming the gap could have a mass between 6 and 28 M ⊕ .

  19. Implementing Electronic Conferencing within a Distance-Based University: University of South Africa Case Study

    Science.gov (United States)

    Kritzinger, E.; Padayachee, K.; Tolmay, M.

    2010-01-01

    The outcome of this paper is primarily to survey and analyse student interactions with electronic conferencing systems and to reflect on the impact of such a system on the students' learning within an open distance learning context. This pilot study is articulated within action research methodology to generate critical reflection on collaborative,…

  20. Anomalous enhancement of the lower critical field deep in the superconducting state of LaRu4As12

    Science.gov (United States)

    Juraszek, J.; Bochenek, Ł.; Wawryk, R.; Henkie, Z.; Konczykowski, M.; Cichorek, T.

    2018-05-01

    LaRu4As12 with the critical temperature Tc = 10.4 K displays several features which point at a non-singlet superconducting order parameter, although the bcc crystal structure of the filled skutterudites does not favour the emergence of multiple energy gaps. LaRu4As12 displays an unexpected enhancement of the lower critical field deep in superconducting state which can be attributed to the existence of two superconducting gaps. At T = 0.4 K, the local magnetization measurements were performed utilizing miniaturized Hall sensors.

  1. Research on the psychological gap, personality and achievement of in-school youth based on regression analysis

    Directory of Open Access Journals (Sweden)

    Lei Zhou

    2017-02-01

    Full Text Available Although our society is in rapid development, the psychological problems among in-school university students are increasingly obvious. According to this problem, this thesis applied the Psychological Gap Scale made by Caixia Ma with EPQ and AMS, and made random questionnaire survey among 400 students in a comprehensive university. The survey found out that the average scores of all psychological gap dimensions exceeded the critical value 3, showing most students in that university have psychological gap. Their personality stability, introversion and extroversion are all above the national norm level while their stubbornness is lower than it. Besides, the students’ motivation in pursuing success is stronger than their motivation in avoiding failure. In the last part, this thesis reached the conclusion that personality leaves a great impact in the students’ psychology through regression analysis model and study of the quantitative relations among personality, achievement and psychological gap.

  2. Transformation of critical theory into apology in the work of Jurgen Habermas

    Directory of Open Access Journals (Sweden)

    Vratuša-Žunjić Vera A.

    2000-01-01

    Full Text Available In the paper is analyzed transformation of one part of 'critical theoreticians' into apologists and ideologists of the new old world capitalist order, within the context of twentieth century social conflicts. In the focus of attention is the article 'Bestiality and Humanism - A War on the Border between Law and Moral', that Habermas published during the 1999 NATO bombing of Yugoslavia and criminal violation of all valid national and international legal norms. It is demonstrated that HabermasÆ substitution of the critique of the gap between the preconditions for reasoned communication and real conditions of distorted communication, by moralizing justification of imperialist elimination of the gap between legality and supposed efficacy of the human rightsÆ defense, conducted to the abandonment of critical theoryÆs constitutive elements.

  3. Tuning characteristic of band gap and waveguide in a multi-stub locally resonant phononic crystal plate

    Directory of Open Access Journals (Sweden)

    Xiao-Peng Wang

    2015-10-01

    Full Text Available In this paper, the tuning characteristics of band gaps and waveguides in a locally resonant phononic crystal structure, consisting of multiple square stubs deposited on a thin homogeneous plate, are investigated. Using the finite element method and supercell technique, the dispersion relationships and power transmission spectra of those structures are calculated. In contrast to a system of one square stub, systems of multiple square stubs show wide band gaps at lower frequencies and an increased quantity of band gaps at higher frequencies. The vibration modes of the band gap edges are analyzed to clarify the mechanism of the generation of the lowest band gap. Additionally, the influence of the stubs arrangement on the band gaps in multi-stub systems is investigated. The arrangements of the stubs were found to influence the band gaps; this is critical to understand for practical applications. Based on this finding, a novel method to form defect scatterers by changing the arrangement of square stubs in a multi-stub perfect phononic crystal plate was developed. Defect bands can be induced by creating defects inside the original complete band gaps. The frequency can then be tuned by changing the defect scatterers’ stub arrangement. These results will help in fabricating devices such as acoustic filters and waveguides whose band frequency can be modulated.

  4. Wide-Gap Chalcopyrites

    CERN Document Server

    Siebentritt, Susanne

    2006-01-01

    Chalcopyrites, in particular those with a wide band gap, are fascinating materials in terms of their technological potential in the next generation of thin-film solar cells and in terms of their basic material properties. They exhibit uniquely low defect formation energies, leading to unusual doping and phase behavior and to extremely benign grain boundaries. This book collects articles on a number of those basic material properties of wide-gap chalcopyrites, comparing them to their low-gap cousins. They explore the doping of the materials, the electronic structure and the transport through interfaces and grain boundaries, the formation of the electric field in a solar cell, the mechanisms and suppression of recombination, the role of inhomogeneities, and the technological role of wide-gap chalcopyrites.

  5. Anion gap as a prognostic tool for risk stratification in critically ill patients - a systematic review and meta-analysis.

    Science.gov (United States)

    Glasmacher, Stella Andrea; Stones, William

    2016-08-30

    Lactate concentration is a robust predictor of mortality but in many low resource settings facilities for its analysis are not available. Anion gap (AG), calculated from clinical chemistry results, is a marker of metabolic acidosis and may be more easily obtained in such settings. In this systematic review and meta-analysis we investigated whether the AG predicts mortality in adult patients admitted to critical care settings. We searched Medline, Embase, Web of Science, Scopus, The Cochrane Library and regional electronic databases from inception until May 2016. Studies conducted in any clinical setting that related AG to in-hospital mortality, in-intensive care unit mortality, 31-day mortality or comparable outcome measures were eligible for inclusion. Methodological quality of included studies was assessed using the Quality in Prognostic Studies tool. Descriptive meta-analysis was performed and the I(2) test was used to quantify heterogeneity. Subgroup analysis was undertaken to identify potential sources of heterogeneity between studies. Nineteen studies reporting findings in 12,497 patients were included. Overall, quality of studies was poor and most studies were rated as being at moderate or high risk of attrition bias and confounding. There was substantial diversity between studies with regards to clinical setting, age and mortality rates of patient cohorts. High statistical heterogeneity was found in the meta-analyses of area under the ROC curve (I(2) = 99 %) and mean difference (I(2) = 97 %) for the observed AG. Three studies reported good discriminatory power of the AG to predict mortality and were responsible for a large proportion of statistical heterogeneity. The remaining 16 studies reported poor to moderate ability of the AG to predict mortality. Subgroup analysis suggested that intravenous fluids affect the ability of the AG to predict mortality. Based on the limited quality of available evidence, a single AG measurement cannot be

  6. Two-gap superconductivity in Mo8Ga41 and its evolution upon vanadium substitution

    Science.gov (United States)

    Verchenko, V. Yu.; Khasanov, R.; Guguchia, Z.; Tsirlin, A. A.; Shevelkov, A. V.

    2017-10-01

    Zero-field and transverse-field muon spin rotation/relaxation (μ SR ) experiments were undertaken in order to elucidate the microscopic properties of a strongly coupled superconductor Mo8Ga41 with Tc=9.8 K. The upper critical field extracted from the transverse-field μ SR data exhibits significant reduction with respect to the data from thermodynamic measurements indicating the coexistence of two independent length scales in the superconducting state. Accordingly, the temperature-dependent magnetic penetration depth of Mo8Ga41 is described using a model in which two s wave superconducting gaps are assumed. A V for Mo substitution in the parent compound leads to the complete suppression of one superconducting gap, and Mo7VGa41 is well described within the single s wave gap scenario. The reduction in the superfluid density and the evolution of the low-temperature resistivity upon V substitution indicate the emergence of a competing state in Mo7VGa41 that may be responsible for the closure of one of the superconducting gaps.

  7. Conceptualizing Astronomical Distances for Urban Populations

    Science.gov (United States)

    Popinchalk, Mark; Olson, Kristen; Ingber, Jenny; O'Brien, Mariel

    2017-01-01

    Students living in urban environments may have a washed-out night sky, but their enthusiasm for astronomy can still shine bright. As an educator, it can sometimes be a challenge to see the opportunities afforded by city living to the teaching of astronomy; however, several benefits can be identified. For example, the intrinsic understanding children have of the distances and scales involved in their everyday life is enhanced when they live in a regimented urban structure. This existing understanding of scale is critical to building a foundation for later conceptualizing of the universe.Leveraging the assets of New York City and the resources found in the American Museum of Natural History, The Science and Nature Program offers students (PreK through 8th grade) robust science learning experiences. To address concepts important for studying astronomy, we present a novel twist on the classic lesson “Earth as a Peppercorn,” by scaling the solar system to the size of New York City. Using local landmarks and their distance in relation to the Museum to represent the planets, students can use their prior knowledge of their surroundings to appreciate the impressive scale of our neighborhood in space in the context of their own neighborhoods. We correlate the activity with NGSS standards, present preliminary feedback on it’s success, and discuss the opportunities to apply a similar model lesson to other astronomical systems.

  8. Self-Organized Criticality and Mass Extinction in Evolutionary Algorithms

    DEFF Research Database (Denmark)

    Krink, Thiemo; Thomsen, Rene

    2001-01-01

    The gaps in the fossil record gave rise to the hypothesis that evolution proceeded in long periods of stasis, which alternated with occasional, rapid changes that yielded evolutionary progress. One mechanism that could cause these punctuated bursts is the re-colonbation of changing and deserted...... at a critical state between chaos and order, known as self-organized criticality (SOC). Based on this background, we used SOC to control the size of spatial extinction zones in a diffusion model. The SOC selection process was easy to implement and implied only negligible computational costs. Our results show...

  9. Study of gap conductance model for thermo mechanical fully coupled finite element model

    International Nuclear Information System (INIS)

    Kim, Hyo Cha; Yang, Yong Sik; Kim, Dae Ho; Bang, Je Geon; Kim, Sun Ki; Koo, Yang Hyun

    2012-01-01

    A light water reactor (LWR) fuel rod consists of zirconium alloy cladding and uranium dioxide pellets, with a slight gap between them. Therefore, the mechanical integrity of zirconium alloy cladding is the most critical issue, as it is an important barrier for fission products released into the environment. To evaluate the stress and strain of the cladding during operation, fuel performance codes with a one-dimensional (1D) approach have been reported since the 1970s. However, it is difficult for a 1D model to simulate the stress and strain of the cladding accurately owing to a lack of degree of freedom. A LWR fuel performance code should include thermo-mechanical coupled model owing to the existence of the fuel-cladding gap. Generally, the gap that is filled with helium gas results in temperature drop along radius direction. The gap conductance that determines temperature gradient within the gap is very sensitive to gap thickness. For instance, once the gap size increases up to several microns in certain region, difference of surface temperatures increases up to 100 Kelvin. Therefore, iterative thermo-mechanical coupled analysis is required to solve temperature distribution throughout pellet and cladding. Consequently, the Finite Element (FE) module, which can simulate a higher degree of freedom numerically, is an indispensable requirement to understand the thermomechanical behavior of cladding. FRAPCON-3, which is reliable performance code, has iterative loop for thermo-mechanical coupled calculation to solve 1D gap conductance model. In FEMAXI-III, 1D thermal analysis module and FE module for stress-strain analysis were separated. 1D thermal module includes iterative analysis between them. DIONISIO code focused on thermal contact model as function of surface roughness and contact pressure when the gap is closed. In previous works, gap conductance model has been developed only for 1D model or hybrid model (1D and FE). To simulate temperature, stress and strain

  10. Students' qualification in environmental and sustainability education—epistemic gaps or composites of critical thinking?

    Science.gov (United States)

    Hasslöf, Helen; Lundegård, Iann; Malmberg, Claes

    2016-01-01

    In an 'age of measurement' where students' qualification is a hot topic on the political agenda, it is of interest to ask what the function of qualification might implicate in relation to a complex issue as Education for Sustainable Development (ESD) and what function environmental and sustainability issues serve in science education. This paper deals with how secondary and upper secondary teachers in discussions with colleagues articulate qualification in relation to educational aims of ESD. With inspiration from discourse theory, the teachers' articulations of qualification are analysed and put in relation to other functions of education (qualification, socialisation and subjectification). The results of this study show three discourses of qualification: scientific reasoning, awareness of complexity and to be critical. The discourse of 'qualification as to be critical' is articulated as a composite of differing epistemological views. In this discourse, the teachers undulate between rationalistic epistemological views and postmodern views, in a pragmatic way, to articulate a discourse of critical thinking which serves as a reflecting tool to bring about different ways of valuing issues of sustainability, which reformulates 'matter of facts' towards 'matter of concerns'

  11. Evaluation strategies for midwifery education linked to digital media and distance delivery technology.

    Science.gov (United States)

    Fullerton, Judith T; Ingle, Henry T

    2003-01-01

    The goal of the teaching and learning process for health professionals is the acquisition of a fundamental core of knowledge, the demonstration of critical thinking ability, and the demonstration of competency in the performance of clinical skills. Teaching and learning in distance education programs require that the administration, teachers, and students be creative in developing evaluation strategies that can be adapted to the challenges of the cyberspace on-line educational environment. Evaluation standards for distance education programs recently have been delineated by federal agencies, private organizations, and academic accreditation associations. These standards are linked to principles of sound education practice that promote program quality, high levels of student-faculty interaction, and support effective teaching and learning in the distance education context. A growing body of evidence supports the conclusion that technology-enhanced teaching is equivalent in effectiveness compared with traditional methods when student-learning outcomes are the focus of measurement. An allied body of literature offers model approaches that can be useful to educators who must also conduct the evaluation of clinical skills, provide feedback, and promote socialization to the nurse-midwifery/midwifery role for students being educated in whole or in part through instruction delivered at a distance.

  12. The psychostimulant modafinil enhances gap junctional communication in cortical astrocytes.

    Science.gov (United States)

    Liu, Xinhe; Petit, Jean-Marie; Ezan, Pascal; Gyger, Joël; Magistretti, Pierre; Giaume, Christian

    2013-12-01

    Sleep-wake cycle is characterized by changes in neuronal network activity. However, for the last decade there is increasing evidence that neuroglial interaction may play a role in the modulation of sleep homeostasis and that astrocytes have a critical impact in this process. Interestingly, astrocytes are organized into communicating networks based on their high expression of connexins, which are the molecular constituents of gap junction channels. Thus, neuroglial interactions should also be considered as the result of the interplay between neuronal and astroglial networks. Here, we investigate the effect of modafinil, a wakefulness-promoting agent, on astrocyte gap junctional communication. We report that in the cortex modafinil injection increases the expression of mRNA and protein of connexin 30 but not those of connexin 43, the other major astroglial connexin. These increases are correlated with an enhancement of intercellular dye coupling in cortical astrocytes, which is abolished when neuronal activity is silenced by tetrodotoxin. Moreover, gamma-hydroxybutyric acid, which at a millimolar concentration induces sleep, has an opposite effect on astroglial gap junctions in an activity-independent manner. These results support the proposition that astroglia may play an important role in complex physiological brain functions, such as sleep regulation, and that neuroglial networking interaction is modified during sleep-wake cycle. This article is part of the Special Issue Section entitled 'Current Pharmacology of Gap Junction Channels and Hemichannels'. Copyright © 2013. Published by Elsevier Ltd.

  13. THE DISTANCE TO M51

    Energy Technology Data Exchange (ETDEWEB)

    McQuinn, Kristen B. W. [University of Texas at Austin, McDonald Observatory, 2515 Speedway, Stop C1400 Austin, TX 78712 (United States); Skillman, Evan D. [Minnesota Institute for Astrophysics, School of Physics and Astronomy, 116 Church Street, S.E., University of Minnesota, Minneapolis, MN 55455 (United States); Dolphin, Andrew E. [Raytheon Company, 1151 E. Hermans Road, Tucson, AZ 85756 (United States); Berg, Danielle [Center for Gravitation, Cosmology and Astrophysics, Department of Physics, University of Wisconsin Milwaukee, 1900 East Kenwood Boulevard, Milwaukee, WI 53211 (United States); Kennicutt, Robert, E-mail: kmcquinn@astro.as.utexas.edu [Institute for Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom)

    2016-07-20

    Great investments of observing time have been dedicated to the study of nearby spiral galaxies with diverse goals ranging from understanding the star formation process to characterizing their dark matter distributions. Accurate distances are fundamental to interpreting observations of these galaxies, yet many of the best studied nearby galaxies have distances based on methods with relatively large uncertainties. We have started a program to derive accurate distances to these galaxies. Here we measure the distance to M51—the Whirlpool galaxy—from newly obtained Hubble Space Telescope optical imaging using the tip of the red giant branch method. We measure the distance modulus to be 8.58 ± 0.10 Mpc (statistical), corresponding to a distance modulus of 29.67 ± 0.02 mag. Our distance is an improvement over previous results as we use a well-calibrated, stable distance indicator, precision photometry in a optimally selected field of view, and a Bayesian Maximum Likelihood technique that reduces measurement uncertainties.

  14. The Potential of Critical Feminist Citizenship Frameworks for Citizenship and Social Justice in Higher Education

    Science.gov (United States)

    Bozalek, Vivienne; Carolissen, Ronelle

    2012-01-01

    There is a paucity of South African literature that uses feminist critical approaches as a conceptual tool to examine intersections of social justice and citizenship. This article aims to address this gap by examining the potential of critical feminist approaches to transform conceptions of citizenship in higher education. It outlines how…

  15. A boosting framework for visuality-preserving distance metric learning and its application to medical image retrieval.

    Science.gov (United States)

    Yang, Liu; Jin, Rong; Mummert, Lily; Sukthankar, Rahul; Goode, Adam; Zheng, Bin; Hoi, Steven C H; Satyanarayanan, Mahadev

    2010-01-01

    Similarity measurement is a critical component in content-based image retrieval systems, and learning a good distance metric can significantly improve retrieval performance. However, despite extensive study, there are several major shortcomings with the existing approaches for distance metric learning that can significantly affect their application to medical image retrieval. In particular, "similarity" can mean very different things in image retrieval: resemblance in visual appearance (e.g., two images that look like one another) or similarity in semantic annotation (e.g., two images of tumors that look quite different yet are both malignant). Current approaches for distance metric learning typically address only one goal without consideration of the other. This is problematic for medical image retrieval where the goal is to assist doctors in decision making. In these applications, given a query image, the goal is to retrieve similar images from a reference library whose semantic annotations could provide the medical professional with greater insight into the possible interpretations of the query image. If the system were to retrieve images that did not look like the query, then users would be less likely to trust the system; on the other hand, retrieving images that appear superficially similar to the query but are semantically unrelated is undesirable because that could lead users toward an incorrect diagnosis. Hence, learning a distance metric that preserves both visual resemblance and semantic similarity is important. We emphasize that, although our study is focused on medical image retrieval, the problem addressed in this work is critical to many image retrieval systems. We present a boosting framework for distance metric learning that aims to preserve both visual and semantic similarities. The boosting framework first learns a binary representation using side information, in the form of labeled pairs, and then computes the distance as a weighted Hamming

  16. Encyclopedia of distances

    CERN Document Server

    Deza, Michel Marie

    2009-01-01

    Distance metrics and distances have become an essential tool in many areas of pure and applied Mathematics. This title offers both independent introductions and definitions, while at the same time making cross-referencing easy through hyperlink-like boldfaced references to original definitions.

  17. Influence of the ``second gap'' on the optical absorption of transparent conducting oxides

    Science.gov (United States)

    Ha, Viet-Anh; Waroquiers, David; Rignanese, Gian-Marco; Hautier, Geoffroy

    Transparent conducting oxides (TCOs) are critical to many technologies (e.g., thin-film solar cells, flat-panel displays or organic light-emitting diodes). TCOs are heavily doped (n or p-type) oxides that satisfy many design criteria such as high transparency to visible light (i.e., a band gap > 3 eV), high concentration and mobility of carriers (leading to high conductivity), ... In such (highly doped) systems, optical transitions from the conduction band minimum to higher energy bands in n-type or from lower energy bands to the valence band maximum in p-type are possible and can degrade transparency. In fact, it has been claimed that a high energy (> 3eV) for any of these transitions made possible by doping, commonly referred as a high ``second gap'', is a necessary design criterion for high performance TCOs. Here, we study the influence of this second gap on the transparency of doped TCOs by using ab initio calculations within the random phase approximation (RPA) for several well-known p-type and n-type TCOs. Our work highlights how the second gap affects the transparency of doped TCOs, shining light on more accurate design criteria for high performance TCOs.

  18. On the concept of critical surface excess of micellization.

    Science.gov (United States)

    Talens-Alesson, Federico I

    2010-11-16

    The critical surface excess of micellization (CSEM) should be regarded as the critical condition for micellization of ionic surfactants instead of the critical micelle concentration (CMC). There is a correspondence between the surface excesses Γ of anionic, cationic, and zwitterionic surfactants at their CMCs, which would be the CSEM values, and the critical association distance for ionic pair association calculated using Bjerrum's correlation. Further support to this concept is given by an accurate method for the prediction of the relative binding of alkali cations onto dodecylsulfate (NaDS) micelles. This method uses a relative binding strength parameter calculated from the values of surface excess Γ at the CMC of the alkali dodecylsulfates. This links both the binding of a given cation onto micelles and the onset for micellization of its surfactant salt. The CSEM concept implies that micelles form at the air-water interface unless another surface with greater affinity for micelles exists. The process would start when surfactant monomers are close enough to each other for ionic pairing with counterions and the subsequent assembly of these pairs becomes unavoidable. This would explain why the surface excess Γ values of different surfactants are more similar than their CMCs: the latter are just the bulk phase concentrations in equilibrium with chemicals with different hydrophobicity. An intriguing implication is that CSEM values may be used to calculate the actual critical distances of ionic pair formation for different cations, replacing Bjerrum's estimates, which only discriminate by the magnitude of the charge.

  19. Spectral Gaps of Spin-orbit Coupled Particles in Deformed Traps

    DEFF Research Database (Denmark)

    V. Marchukov, O.; G. Volosniev, A.; V. Fedorov, D.

    2013-01-01

    the spectrum. The effect of a Zeeman term is also considered. Our results demonstrate that variable spectral gaps occur as a function of strength of the Rashba interaction and deformation of the harmonic trapping potential. The single-particle density of states and the critical strength for superfluidity vary...... tremendously with the interaction parameter. The strong variations with Rashba coupling and deformation implies that the few- and many-body physics of spin-orbit coupled systems can be manipulated by variation of these parameters....

  20. Benzo[b]naphthothiophenes and alkyl dibenzothiophenes: molecular tracers for oil migration distances

    Science.gov (United States)

    Li, Meijun; Wang, T.-G.; Shi, Shengbao; Liu, Keyu; Ellis, Geoffrey S.

    2014-01-01

    The secondary migration of petroleum is one of the most critical geological processes responsible for the accumulation of hydrocarbons in a sedimentary basin. Pyrrolic nitrogen compounds such as carbazoles and benzocarbazoles are thought to be practical molecular indicators for estimating relative migration distances of oil. In light oils or condensates, however, considerable analytical errors are usually caused by low concentrations of NSO-compounds. Here we show that polycyclic sulfur aromatic hydrocarbons such as dibenzothiophene, C1∼C3 alkylated dibenzothiophenes and benzo[b]naphthothiophenes, which are present in relatively higher concentrations than the pyrrolic nitrogen compounds, exhibit changes in both absolute and relative concentrations that correlate with migration distances. The polycyclic sulfur aromatic hydrocarbons related parameters — benzo[b]naphtho[2,1-d]thiophene/{benzo[b]naphtho[2,1-d]thiophene + benzo[b]naphtho[1,2-d]thiophene} (abbreviated as [2,1]BNT/([2,1]BNT+[1,2]BNT) and the concentration of total dibenzothiophenes plus benzo[b]naphthothiophenes — are proposed by this paper to trace the oil migration distances.

  1. Determining the ’Gap

    Science.gov (United States)

    2009-05-01

    Army training doctrine, and by adjusting the curriculum of the officer core in order to close the knowledge gap . The author closes by concluding...fight. The research to find these gaps begins with a process trace of doctrine from 1976 to the present, starting with the advent of Active Defense...discovering the one gap , three were found. Upon further examination below, even these initially perceived gaps dissipate under close scrutiny. Gap

  2. Entrainment, retention, and transport of freely swimming fish in junction gaps between commercial barges operating on the Illinois Waterway

    Science.gov (United States)

    Davis, Jeremiah J.; Jackson, P. Ryan; Engel, Frank; LeRoy, Jessica Z.; Neeley, Rebecca N.; Finney, Samuel T.; Murphy, Elizabeth A.

    2016-01-01

    Large Electric Dispersal Barriers were constructed in the Chicago Sanitary and Ship Canal (CSSC) to prevent the transfer of invasive fish species between the Mississippi River Basin and the Great Lakes Basin while simultaneously allowing the passage of commercial barge traffic. We investigated the potential for entrainment, retention, and transport of freely swimming fish within large gaps (> 50 m3) created at junction points between barges. Modified mark and capture trials were employed to assess fish entrainment, retention, and transport by barge tows. A multi-beam sonar system enabled estimation of fish abundance within barge junction gaps. Barges were also instrumented with acoustic Doppler velocity meters to map the velocity distribution in the water surrounding the barge and in the gap formed at the junction of two barges. Results indicate that the water inside the gap can move upstream with a barge tow at speeds near the barge tow travel speed. Water within 1 m to the side of the barge junction gaps was observed to move upstream with the barge tow. Observed transverse and vertical water velocities suggest pathways by which fish may potentially be entrained into barge junction gaps. Results of mark and capture trials provide direct evidence that small fish can become entrained by barges, retained within junction gaps, and transported over distances of at least 15.5 km. Fish entrained within the barge junction gap were retained in that space as the barge tow transited through locks and the Electric Dispersal Barriers, which would be expected to impede fish movement upstream.

  3. Mechanics of Fluid-Filled Interstitial Gaps. I. Modeling Gaps in a Compact Tissue.

    Science.gov (United States)

    Parent, Serge E; Barua, Debanjan; Winklbauer, Rudolf

    2017-08-22

    Fluid-filled interstitial gaps are a common feature of compact tissues held together by cell-cell adhesion. Although such gaps can in principle be the result of weak, incomplete cell attachment, adhesion is usually too strong for this to occur. Using a mechanical model of tissue cohesion, we show that, instead, a combination of local prevention of cell adhesion at three-cell junctions by fluidlike extracellular material and a reduction of cortical tension at the gap surface are sufficient to generate stable gaps. The size and shape of these interstitial gaps depends on the mechanical tensions between cells and at gap surfaces, and on the difference between intracellular and interstitial pressures that is related to the volume of the interstitial fluid. As a consequence of the dependence on tension/tension ratios, the presence of gaps does not depend on the absolute strength of cell adhesion, and similar gaps are predicted to occur in tissues of widely differing cohesion. Tissue mechanical parameters can also vary within and between cells of a given tissue, generating asymmetrical gaps. Within limits, these can be approximated by symmetrical gaps. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  4. [Effects of gap size on seedling natural regeneration in artificial Pinus tabulaeformis plantation].

    Science.gov (United States)

    Han, Wen-Juan; Yuan, Xiao-Qing; Zhang, Wen-Hui

    2012-11-01

    To clarify the effects of gap size created by thinning on the seedling natural regeneration in artificial Pinus tabulaeformis plantation, a plot investigation was conducted to study the ecological factors and the age structure, height, diameter, length of needles, and dry biomass of roots, stems, and needles of 1-10 year-old seedlings in different habitats, and a path analysis was made on the environmental factors affecting the seedling regeneration. Obvious differences were observed in the ecological factors in different size gaps and slope aspects. There lacked of above 3 year-old seedlings in understory and of above 7 year-old seedlings in small gap, and the seedlings of 5 and 6 year-old were lesser in big gap. The 1-10 year-old seedlings could be divided into 3 development phases, i. e. , 1-3 year-old, 4-7 year-old, and 8-10 year-old seedlings, among which, 1-3 year-old seedlings were critical for the establishment and growth of the population. The growth situation of the seedlings in different habitats was in order of big gap in shady slope > big gap in sunny slope > small gap in sunny slope > small gap in shady slope > understory in sunny slope > understory in shady slope. Path analysis showed light intensity had decisive positive effects on the seedling number of different development phases, shrub coverage had decisive negative effects on the seedling number of 4-7 year-old and 8-10 year-old phases, whereas humus dry mass had negative effects on the seedling number of 4-7 year-old but positive effects on the seedling number of 8-10 year-old. It was suggested that in the management of artificial P. tabulaeformis plantation, relatively high intensity thinning combined with shrub clearing should be adopted to provide favorable conditions for the sustainable development of P. tabulaeformis population.

  5. Long-Distance Free Fall

    Science.gov (United States)

    Gallant, Joseph

    1999-04-01

    One of the goals of physics education is to instill a sense of wonder in our students. We hope our natural curiosity will rub off on them and that they will apply the critical thinking skills we teach them to other aspects of their lives outside the classroom. As an example of this, consider the situation described in Milton's epic poem ``Paradise Lost''. Milton wrote that when the devil was cast out of heaven, he fell for nine days before landing in hell. In Milton's universe, hell is a separate place from Earth, but many people place hell at the center of the Earth. Based on these ideas, we can apply Newton's laws of motion to calculate the distance from heaven to Earth. This exercise is an example of the kind of intellectual exercise a physicist (or a physics student) might carry out when confronted with such information. We apply the basic principles of physics to a situation described in work of literature while making no attempt to validate or refute any philosophy, theology or ideology.

  6. Ultrafast Gap Dynamics and Electronic Interactions in a Photoexcited Cuprate Superconductor

    Directory of Open Access Journals (Sweden)

    S. Parham

    2017-10-01

    Full Text Available We perform time- and angle-resolved photoemission spectroscopy (trARPES on optimally doped Bi_{2}Sr_{2}CaCu_{2}O_{8+δ} (BSCCO-2212 using sufficient energy resolution (9 meV to resolve the k-dependent near-nodal gap structure on time scales where the concept of an electronic pseudotemperature is a useful quantity, i.e., after electronic thermalization has occurred. We study the ultrafast evolution of this gap structure, uncovering a very rich landscape of decay rates as a function of angle, temperature, and energy. We explicitly focus on the quasiparticle states at the gap edge as well as on the spectral weight inside the gap that “fills” the gap—understood as an interaction, or self-energy effect—and we also make high resolution measurements of the nodal states, enabling a direct and accurate measurement of the electronic temperature (or pseudotemperature of the electrons in the system. Rather than the standard method of interpreting these results using individual quasiparticle scattering rates that vary significantly as a function of angle, temperature, and energy, we show that the entire landscape of relaxations can be understood by modeling the system as following a nonequilibrium, electronic pseudotemperature that controls all electrons in the zone. Furthermore, this model has zero free parameters, as we obtain the crucial information of the SC gap Δ and the gap-filling strength Γ_{TDoS} by connecting to static ARPES measurements. The quantitative and qualitative agreement between data and model suggests that the critical parameters and interactions of the system, including the pairing interactions, follow parametrically from the electronic pseudotemperature. We expect that this concept will be relevant for understanding the ultrafast response of a great variety of electronic materials, even though the electronic pseudotemperature may not be directly measurable.

  7. Computing gap free Pareto front approximations with stochastic search algorithms.

    Science.gov (United States)

    Schütze, Oliver; Laumanns, Marco; Tantar, Emilia; Coello, Carlos A Coello; Talbi, El-Ghazali

    2010-01-01

    Recently, a convergence proof of stochastic search algorithms toward finite size Pareto set approximations of continuous multi-objective optimization problems has been given. The focus was on obtaining a finite approximation that captures the entire solution set in some suitable sense, which was defined by the concept of epsilon-dominance. Though bounds on the quality of the limit approximation-which are entirely determined by the archiving strategy and the value of epsilon-have been obtained, the strategies do not guarantee to obtain a gap free approximation of the Pareto front. That is, such approximations A can reveal gaps in the sense that points f in the Pareto front can exist such that the distance of f to any image point F(a), a epsilon A, is "large." Since such gap free approximations are desirable in certain applications, and the related archiving strategies can be advantageous when memetic strategies are included in the search process, we are aiming in this work for such methods. We present two novel strategies that accomplish this task in the probabilistic sense and under mild assumptions on the stochastic search algorithm. In addition to the convergence proofs, we give some numerical results to visualize the behavior of the different archiving strategies. Finally, we demonstrate the potential for a possible hybridization of a given stochastic search algorithm with a particular local search strategy-multi-objective continuation methods-by showing that the concept of epsilon-dominance can be integrated into this approach in a suitable way.

  8. Gender Pay Gap, Productivity Gap and Discrimination in Canadian Clothing Manufacturing in 1870

    OpenAIRE

    Catherine L McDevitt; James R Irwin; Kris Inwood

    2009-01-01

    Women's earnings were less than men's in Canadian clothing factories in 1870. Orthodox neoclassical theory would explain that gender pay gap as a reflection of a gender productivity gap. Using classical hypothesis testing we reject that view, based on a large cross-section of 1870 census data. We find the gender pay gap was significantly larger than the gender productivity gap, much as Hellerstein et al. [1999] found for US manufacturing circa 1990. Our results are clear and compell...

  9. Critical Neuroscience – or Critical Science? A Perspective on the Perceived Normative Significance of Neuroscience

    Directory of Open Access Journals (Sweden)

    Stephan eSchleim

    2014-05-01

    Full Text Available Members of the Critical Neuroscience initiative raised the question whether the perceived normative significance of neuroscience is justified by the discipline’s actual possibilities. In this paper I show how brain research was assigned the ultimate political, social, and moral authority by some leading researchers who suggested that neuroscientists should change their research priorities, promising solutions to social challenges in order to increase research funds. Discussing the two examples of cognitive enhancement and the neuroscience of (immoral behavior I argue that there is indeed a gap between promises and expectations on the one hand and knowledge and applications on the other. However it would be premature to generalize this to the neurosciences at large, whose knowledge-producing, innovative, and economic potentials have just recently been confirmed by political and scientific decision-makers with the financial support for the Human Brain Project and the BRAIN Initiative. Finally, I discuss two explanations for the analyzed communication patterns and argue why Critical Neuroscience is necessary, but not sufficient. A more general Critical Science movement is required to improve the scientific incentive system.

  10. Learner characteristics involved in distance learning

    Energy Technology Data Exchange (ETDEWEB)

    Cernicek, A.T.; Hahn, H.A.

    1991-01-01

    Distance learning represents a strategy for leveraging resources to solve educational and training needs. Although many distance learning programs have been developed, lessons learned regarding differences between distance learning and traditional education with respect to learner characteristics have not been well documented. Therefore, we conducted a survey of 20 distance learning professionals. The questionnaire was distributed to experts attending the second Distance Learning Conference sponsored by Los Alamos National Laboratory. This survey not only acquired demographic information from each of the respondents but also identified important distance learning student characteristics. Significant distance learner characteristics, which were revealed statistically and which influence the effectiveness of distance learning, include the following: reading level, student autonomy, and self-motivation. Distance learning cannot become a more useful and effective method of instruction without identifying and recognizing learner characteristics. It will be important to consider these characteristics when designing all distance learning courses. This paper will report specific survey findings and their implications for developing distance learning courses. 9 refs., 6 tabs.

  11. Highlighting the gap between critical outcomes requirements and built environment education in South Africa

    CSIR Research Space (South Africa)

    Ampofo-Anti, NL

    2007-06-01

    Full Text Available This paper aims to highlight the discrepancies between current built environment education and Critical Outcomes requirements of the South African National Qualifications Framework (NQF)...

  12. Building that Bridge over the Skills Gap

    Directory of Open Access Journals (Sweden)

    Janani Ramanathan

    2017-10-01

    Full Text Available Employers worldwide are seeking and failing to find in new recruits many skills that are critical for success. Skills that enable employees to work as part of a team, communicate effectively, take decisions, lead, adapt to change and solve problems creatively are not often found in fresh graduates. Education does not impart these skills as efficiently as it does academic knowledge and subject-specific skills. A change in the pedagogy and content of education is required to bridge the increasing skills gap we face today. The World University Consortium has identified themes that must be part of our future education, and this article highlights methods and strategies that can implement these ideas.

  13. Distance Magic-Type and Distance Antimagic-Type Labelings of Graphs

    Science.gov (United States)

    Freyberg, Bryan J.

    Generally speaking, a distance magic-type labeling of a graph G of order n is a bijection l from the vertex set of the graph to the first n natural numbers or to the elements of a group of order n, with the property that the weight of each vertex is the same. The weight of a vertex x is defined as the sum (or appropriate group operation) of all the labels of vertices adjacent to x. If instead we require that all weights differ, then we refer to the labeling as a distance antimagic-type labeling. This idea can be generalized for directed graphs; the weight will take into consideration the direction of the arcs. In this manuscript, we provide new results for d-handicap labeling, a distance antimagic-type labeling, and introduce a new distance magic-type labeling called orientable Gamma-distance magic labeling. A d-handicap distance antimagic labeling (or just d-handicap labeling for short) of a graph G = ( V,E) of order n is a bijection l from V to the set {1,2,...,n} with induced weight function [special characters omitted]. such that l(xi) = i and the sequence of weights w(x 1),w(x2),...,w (xn) forms an arithmetic sequence with constant difference d at least 1. If a graph G admits a d-handicap labeling, we say G is a d-handicap graph. A d-handicap incomplete tournament, H(n,k,d ) is an incomplete tournament of n teams ranked with the first n natural numbers such that each team plays exactly k games and the strength of schedule of the ith ranked team is d more than the i + 1st ranked team. That is, strength of schedule increases arithmetically with strength of team. Constructing an H(n,k,d) is equivalent to finding a d-handicap labeling of a k-regular graph of order n.. In Chapter 2 we provide general constructions for every d for large classes of both n and k, providing breadfth and depth to the catalog of known H(n,k,d)'s. In Chapters 3 - 6, we introduce a new type of labeling called orientable Gamma-distance magic labeling. Let Gamma be an abelian group of order

  14. Distance-transitive graphs

    NARCIS (Netherlands)

    Cohen, A.M.; Beineke, L.W.; Wilson, R.J.; Cameron, P.J.

    2004-01-01

    In this chapter we investigate the classification of distance-transitive graphs: these are graphs whose automorphism groups are transitive on each of the sets of pairs of vertices at distance i, for i = 0, 1,.... We provide an introduction into the field. By use of the classification of finite

  15. Critical Care nurses' understanding of the NHS knowledge and skills framework. An interpretative phenomenological analysis.

    Science.gov (United States)

    Stewart, Laura F M; Rae, Agnes M

    2013-01-01

    This small-scale research study aimed to explore Critical Care nurses' understanding of the National Health Service (NHS) Knowledge and Skills Framework (KSF) in relationship to its challenges and their nursing role. The NHS KSF is central to the professional development of nurses in Critical Care and supports the effective delivery of health care in the UK. KSF was implemented in 2004 yet engagement seems lacking with challenges often identified. This qualitative study adopted an Interpretative Phenomenological Analysis framework. Data were collected from five Critical Care nurses using semi-structured interviews that were transcribed for analysis. Two super-ordinate themes of 'engagement' and 'theory-practice gap' were identified. Six subthemes of 'fluency', 'transparency', 'self-assessment', 'achieving for whom', 'reflection' and 'the nursing role' further explained the super-ordinate themes. Critical Care nurses demonstrated layers of understanding about KSF. Challenges identified were primarily concerned with complex language, an unclear process and the use of reflective and self-assessment skills. Two theory-practice gaps were found. Critical Care nurses understood the principles of KSF but they either did not apply or did not realize they applied these principles. They struggled to relate KSF to Critical Care practice and felt it did not capture the 'essence' of their nursing role in Critical Care. Recommendations were made for embedding KSF into Critical Care practice, using education and taking a flexible approach to KSF to support the development and care delivery of Critical Care nurses. © 2012 The Authors. Nursing in Critical Care © 2012 British Association of Critical Care Nurses.

  16. Effective Leadership Is Not Enough: Critical Approaches to Closing the Racial Discipline Gap

    Science.gov (United States)

    DeMatthews, David

    2016-01-01

    A review of student discipline and suspension data disaggregated by race highlights how school leader biases influence disciplinary decisions. Yet, the majority of principal preparation programs have failed to develop structures and norms that result in critical conversations pertaining to race and racial inequities. This article is written from a…

  17. Experiments on criticality carried out from 1975 till 1980

    International Nuclear Information System (INIS)

    Heinicke, W.; Tischer, A.; Weber, W.J.

    1981-11-01

    The report on hand includes the experiments on criticality published from 1975 till 1980. About 90 experiments with the most important related data are listed. They are capable of being called up, with the data base system KRITEXP, by 14 different descriptors or printed in any arrangement or order. This is the basis for a global or purposeful verification of the calculating method for criticality safety. The proof of reliability of the calculations for the criticality analysis are immediately relevant for the licencing procedure under atomic law for all plants of the nuclear fuel cycle where nuclear fuels are handled. Since no criticality experiments are being carried out in the Federal Republic of Germany, the data collection on hand will help to fill this gap with regard to the assessment of experiments carried out in other countries. (orig.) [de

  18. Genetic and functional analysis of the gene encoding GAP-43 in schizophrenia.

    Science.gov (United States)

    Shen, Yu-Chih; Tsai, Ho-Min; Cheng, Min-Chih; Hsu, Shih-Hsin; Chen, Shih-Fen; Chen, Chia-Hsiang

    2012-02-01

    In earlier reports, growth-associated protein 43 (GAP-43) has been shown to be critical for initial establishment or reorganization of synaptic connections, a process thought to be disrupted in schizophrenia. Additionally, abnormal GAP-43 expression in different brain regions has been linked to this disorder in postmortem brain studies. In this study, we investigated the involvement of the gene encoding GAP-43 in the susceptibility to schizophrenia. We searched for genetic variants in the promoter region and 3 exons (including both UTR ends) of the GAP-43 gene using direct sequencing in a sample of patients with schizophrenia (n=586) and non-psychotic controls (n=576), both being Han Chinese from Taiwan, and conducted an association and functional study. We identified 11 common polymorphisms in the GAP-43 gene. SNP and haplotype-based analyses displayed no associations with schizophrenia. Additionally, we identified 4 rare variants in 5 out of 586 patients, including 1 variant located at the promoter region (c.-258-4722G>T) and 1 synonymous (V110V) and 2 missense (G150R and P188L) variants located at exon 2. No rare variants were found in the control subjects. The results of the reporter gene assay demonstrated that the regulatory activity of construct containing c.-258-4722T was significantly lower as compared to the wild type construct (c.-258-4722G; panalysis also demonstrated the functional relevance of other rare variants. Our study lends support to the hypothesis of multiple rare mutations in schizophrenia, and it provides genetic clues that indicate the involvement of GAP-43 in this disorder. Copyright © 2011 Elsevier B.V. All rights reserved.

  19. STRATEGIES TO IMPROVE RETENTION OF POSTGRADUATE BUSINESS STUDENTS IN DISTANCE EDUCATION COURSES: An Australian Case

    Directory of Open Access Journals (Sweden)

    David CARROLL,

    2013-01-01

    Full Text Available In spite of the clear value of postgraduate business students to many providers of distance education courses, the factors affecting the retention of these students have received limited attention in the literature. In addressing this gap, this paper presents the findings of a qualitative study into the factors affecting the retention of postgraduate business students at a major Australian distance education university. The findings of this study suggest that a range of situational, dispositional and attitudinal factors impact upon student retention on this context, both as enablers of and obstacles to ongoing participation. In many cases, these factors differ to those identified in the existing literature on student retention. Based on these findings, we present a range of strategies designed to improve the retention of postgraduate business students by maximising enabling factors and minimising the impact of any identified obstacles. Limitations of the study and suggestions for further research are also presented.

  20. Distance learning for training business game tutors

    Directory of Open Access Journals (Sweden)

    Mariana de Toledo Marinho

    Full Text Available Abstract This work is the result of research that proposes the incorporation of Distance Learning into a Business Game as a strategy to enhance tutor training, considering entrepreneurship difficulties faced by public school teachers. Part of the problem could be attributed to subject type, because, in general, it is not common to find entrepreneurship on school curricula. The Distance Learning (DL activities were developed using the Moodle platform and structured by topic to increase educational flexibility and achieve a better balance between individual reflection and online discussion. It was developed in four steps: course content development; course evaluation by computer technicians; restructuring the course based on course evaluation done by computer technicians and course evaluation by teachers from the public school system. A preliminary test was performed with informatics technicians to technically evaluate the learning environment. Based on this, the course was restructured, applying corrections and adjustments to improve environment usability. After corrections, a final test was conducted with public school system teachers to analyze user perception, which gave a positive result. Virtual learning environment evaluation is complex and multidisciplinary, requiring the technical knowledge of internet programming and a conceptual knowledge of education, especially in the field of learning. When the evaluation done by teachers was examined, it was found that deficiencies pointed out by computer technicians had been resolved, giving a positive rating. This current research concludes that DL can improve the use of games, because it is possible to structure the content related to the learning gaps of specific groups of students. In this respect the use of games results can guide the development of content.

  1. A comparison of gap-filling approaches for Landsat-7 satellite data

    KAUST Repository

    Yin, Gaohong

    2017-08-10

    The purpose of this study is to assess the relative performance of four different gap-filling approaches across a range of land-surface conditions, including both homogeneous and heterogeneous areas as well as in scenes with abrupt changes in landscape elements. The techniques considered in this study include: (1) Kriging and co-Kriging; (2) geostatistical neighbourhood similar pixel interpolator (GNSPI); (3) a weighted linear regression (WLR) algorithm; and (4) the direct sampling (DS) method. To examine the impact of image availability and the influence of temporal distance on the selection of input training data (i.e. time separating the training data from the gap-filled target image), input images acquired within the same season (temporally close) as well as in different seasons (temporally far) to the target image were examined, as was the case of using information only within the target image itself. Root mean square error (RMSE), mean spectral angle (MSA), and coefficient of determination (R-2) were used as the evaluation metrics to assess the prediction results. In addition, the overall accuracy (OA) and kappa coefficient (kappa) were used to assess a land-cover classification based on the gap-filled images. Results show that all of the gap-filling approaches provide satisfactory results for the homogeneous case, with R-2 > 0.93 for bands 1 and 2 in all cases and R-2 > 0.80 for bands 3 and 4 in most cases. For the heterogeneous example, GNSPI performs the best, with R-2 > 0.85 for all tested cases. WLR and GNSPI exhibit equivalent accuracy when a temporally close input image is used (i.e. WLR and GNSPI both have an R-2 equal to 0.89 for band 1). For the case of abrupt changes in scene elements or in the absence of ancillary data, the DS approach outperforms the other tested methods.

  2. A comparison of gap-filling approaches for Landsat-7 satellite data

    KAUST Repository

    Yin, Gaohong; Mariethoz, Gregoire; Sun, Ying; McCabe, Matthew

    2017-01-01

    The purpose of this study is to assess the relative performance of four different gap-filling approaches across a range of land-surface conditions, including both homogeneous and heterogeneous areas as well as in scenes with abrupt changes in landscape elements. The techniques considered in this study include: (1) Kriging and co-Kriging; (2) geostatistical neighbourhood similar pixel interpolator (GNSPI); (3) a weighted linear regression (WLR) algorithm; and (4) the direct sampling (DS) method. To examine the impact of image availability and the influence of temporal distance on the selection of input training data (i.e. time separating the training data from the gap-filled target image), input images acquired within the same season (temporally close) as well as in different seasons (temporally far) to the target image were examined, as was the case of using information only within the target image itself. Root mean square error (RMSE), mean spectral angle (MSA), and coefficient of determination (R-2) were used as the evaluation metrics to assess the prediction results. In addition, the overall accuracy (OA) and kappa coefficient (kappa) were used to assess a land-cover classification based on the gap-filled images. Results show that all of the gap-filling approaches provide satisfactory results for the homogeneous case, with R-2 > 0.93 for bands 1 and 2 in all cases and R-2 > 0.80 for bands 3 and 4 in most cases. For the heterogeneous example, GNSPI performs the best, with R-2 > 0.85 for all tested cases. WLR and GNSPI exhibit equivalent accuracy when a temporally close input image is used (i.e. WLR and GNSPI both have an R-2 equal to 0.89 for band 1). For the case of abrupt changes in scene elements or in the absence of ancillary data, the DS approach outperforms the other tested methods.

  3. Structure damage of GaP monocrystals induced by heavy ions

    International Nuclear Information System (INIS)

    Asherov, K.; Otto, G.; Bugrov, V.N.; Karamyan, S.A.

    1983-01-01

    GaP crystals were irradiated with 1 H, 4 He, 20 Ne, 22 Ne, 31 P, 40 Ar ions at the energy interval from 0.3 up to 8 MeV/nucleon and the dose density from 10 13 up to 10 18 cm -2 . Their damage at the irradiation was controlled using the blocking effect for ion elastic scattering. Damaged monocrystalline samples are analysed by one Kossel effect on the proton beam and the increase of the interplane distance in the crystal lattice is determined as a function of the dose density. On the base of the measured values a correlation is found between the ion damage action on the single crystal and the nuclear stopping power of the ion in the medium

  4. Development of Model for Pedestrian Gap Based on Land Use Pattern at Midblock Location and Estimation of Delay at Intersections

    Science.gov (United States)

    Ramesh, Adepu; Ashritha, Kilari; Kumar, Molugaram

    2018-04-01

    Walking has always been a prime source of human mobility for short distance travel. Traffic congestion has become a major problem for safe pedestrian crossing in most of the metropolitan cities. This has emphasized for providing a sufficient pedestrian gap for safe crossing on urban road. The present works aims in understanding factors that influence pedestrian crossing behaviour. Four locations were chosen for identification of pedestrian crossing behaviour, gap characteristics, waiting time etc., in Hyderabad city. From the study it was observed that pedestrian behaviour and crossing patterns are different and is influenced by land use pattern. A gap acceptance model was developed from the data for improving pedestrian safety at mid-block location; the model was validated using the existing data. Pedestrian delay was estimated at intersection using Highway Capacity Manual (HCM). It was observed that field delays are less when compared to delay arrived from HCM method.

  5. Fewer Diplomas for Men: The Influence of College Experiences on the Gender Gap in College Graduation

    Science.gov (United States)

    Ewert, Stephanie

    2012-01-01

    Women's advantage in college graduation is evident at all socioeconomic levels and for most racial and ethnic groups. This study examines whether college experiences critical to persistence to graduation, including college major, attendance patterns, social integration, and academic performance, contribute to this gender gap in graduation.…

  6. Minding the Gap: Comics as Scaffolding for Critical Literacy Skills in the Classroom

    Science.gov (United States)

    Vie, Stephanie; Dieterle, Brandy

    2016-01-01

    Comics--both digital and print--increasingly make their way to the classroom. Scholars in the field have illustrated the pedagogical value of comics, but there remains little discussion as of yet about how comics can inform critical literacy, a necessary skill for twenty-first-century communication. Here the authors discuss an approach to…

  7. Distance-dependent energy transfer between indole and anthracene moieties in Langmuir Blodgett films

    Science.gov (United States)

    Saha, D. C.; Bhattacharjee, D.; Misra, T. N.

    1998-09-01

    1,2-Diphenyl indole (DPI) and 9,10-diphenyl anthracene (DPA) are non-amphiphilic molecules but form excellent LB films when mixed with stearic acid (SA). Spectroscopic investigations of these films indicate formation of aggregates of DPI and DPA in the mixed LB films. DPA has been used as the quencher of the fluorescence of the DPI donor. Distance-dependent energy transfer between donor and acceptor monolayers in the LB film, where they can be precisely separated by inert spacers of stearic acid layers of varied thickness, is shown to satisfy Khun's quadratic equation. This suggests that the donor excitations are delocalized. The large critical transfer distance estimated from the experimental results has been attributed to the formation of aggregates of the molecules in a LB monolayer.

  8. [Disorders of the acid-base balance and the anion gap].

    Science.gov (United States)

    Kimmel, Martin; Alscher, Mark Dominik

    2016-10-01

    The regulation of the acid-base balance and pH is critical for the organism. The most important buffer system is CO 2 / HCO 3 - . The kidney controls systemic bicarbonate and therefore the metabolic regulation and the lung is relevant for respiratory regulation by an effective CO 2 elimination. There are four acid-base disorders with two metabolic and two respiratory disorders (acidosis and alkalosis). The anion gap enables a further workup of metabolic acidosis. © Georg Thieme Verlag KG Stuttgart · New York.

  9. Characterizing critical phenomena via the Purcell effect

    Science.gov (United States)

    Silva Neto, M. B.; Szilard, D.; Rosa, F. S. S.; Farina, C.; Pinheiro, F. A.

    2017-12-01

    We investigate the role of phase transitions into the spontaneous-emission rate of a single quantum emitter embedded in a critical medium. Using a Landau-Ginzburg approach, we find that in the broken symmetry phase, the emission rate is reduced, or even suppressed, due to the photon mass generated by the Higgs mechanism. Remarkably, its sensitivity to the critical exponents of the phase transition allows for an optical determination of universality classes. When applied to the cases of superconductivity and superfluidity, we show that the Purcell effect also provides valuable information on spectroscopic and thermodynamic quantities, such as the size of the superconducting gap and the discontinuity in the specific heat at the transition. By unveiling that a deeper connection between the Purcell effect and phase transitions exists, we demonstrate that the former is an efficient optical probe of distinct critical phenomena and their associated observables.

  10. The association between distance to public amenities and cardiovascular risk factors among lower income Singaporeans

    Directory of Open Access Journals (Sweden)

    K.K. Lim

    2017-12-01

    Full Text Available Existing evidence on the association between built environment and cardiovascular disease (CVD risk factors focused on the general population, which may not generalize to higher risk subgroups such as those with lower socio-economic status (SES. We examined the associations between distance to 5 public amenities from residential housing (public polyclinic, subsidized private clinic, healthier eatery, public park and train station and 12 CVD risk factors (physical inactivity, medical histories and unhealthy dietary habits among a study sample of low income Singaporeans aged ≥40years (N=1972. Using data from the Singapore Heart Foundation Health Mapping Exercise 2013–2015, we performed a series of logistic mixed effect regressions, accounting for clustering of respondents in residential blocks and multiple comparisons. Each regression analysis used the minimum distance (in km between residential housing and each public amenity as an independent continuous variable and a single risk factor as the dependent variable, controlling for demographic characteristics. Increased distance (geographical inaccessibility to a train station was significantly associated with lower odds of participation in sports whereas greater distance to a subsidized private clinic was associated with lower odds of having high cholesterol diagnosed. Increasing distance to park was positively associated with higher odds of less vegetable and fruits consumption, deep fried food and fast food consumption in the preceding week/month, high BMI at screening and history of diabetes, albeit not achieving statistical significance. Our findings highlighted potential effects of health-promoting amenities on CVD risk factors in urban low-income setting, suggesting gaps for further investigations. Keywords: Cardiovascular risk, Urban health, Socioeconomic status, Singapore, Health promotion, Primary prevention

  11. Fractional Josephson vortices in two-gap superconductor long Josephson junctions

    Science.gov (United States)

    Kim, Ju

    2014-03-01

    We investigated the phase dynamics of long Josephson junctions (LJJ) with two-gap superconductors in the broken time reversal symmetry state. In this LJJ, spatial phase textures (i-solitons) can be excited due to the presence of two condensates and the interband Joesphson effect between them. The presence of a spatial phase texture in each superconductor layer leads to a spatial variation of the critical current density between the superconductor layers. We find that this spatial dependence of the crtitical current density can self-generate magnetic flux in the insulator layer, resulting in Josephson vortices with fractional flux quanta. Similar to the situation in a YBa2 Cu3O7 - x superconductor film grain boundary, the fractionalization of a Josephson vortex arises as a response to either periodic or random excitation of i-solitions. This suggests that magnetic flux measurements may be used to probe i-soliton excitations in multi-gap superconductor LJJs.

  12. Critical developmental periods in the pathogenesis of hypertension

    Czech Academy of Sciences Publication Activity Database

    Kuneš, Jaroslav; Kadlecová, Michaela; Vaněčková, Ivana; Zicha, Josef

    2012-01-01

    Roč. 61, Suppl.1 (2012), S9-S17 ISSN 0862-8408 R&D Projects: GA MŠk(CZ) 1M0510; GA ČR(CZ) GAP304/12/0259 Institutional research plan: CEZ:AV0Z50110509 Institutional support: RVO:67985823 Keywords : critical developmental periods * developmental programming * epigenetics Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery Impact factor: 1.531, year: 2012

  13. Bridge the Gap

    DEFF Research Database (Denmark)

    Marselis, Randi

    2017-01-01

    This article focuses on photo projects organised for teenage refugees by the Society for Humanistic Photography (Berlin, Germany). These projects, named Bridge the Gap I (2015), and Bridge the Gap II (2016), were carried out in Berlin and brought together teenagers with refugee and German...

  14. 'Mind the Gap!'

    DEFF Research Database (Denmark)

    Persson, Karl Gunnar

    This paper challenges the widely held view that sharply falling real transport costs closed the transatlantic gap in grain prices in the second half of the 19th century. Several new results emerge from an analysis of a new data set of weekly wheat prices and freight costs from New York to UK...... markets. Firstly, there was a decline in the transatlantic price gap but it was not sharp and the gap remained substantial. Secondly, the fall in the transatlantic price differential had more to do with improved market and marketing efficiency than with falling transport costs. Thirdly, spurious price...

  15. Sensitivity-Uncertainty Techniques for Nuclear Criticality Safety

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Forrest B. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Rising, Michael Evan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Alwin, Jennifer Louise [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-08-07

    The sensitivity and uncertainty analysis course will introduce students to keff sensitivity data, cross-section uncertainty data, how keff sensitivity data and keff uncertainty data are generated and how they can be used. Discussion will include how sensitivity/uncertainty data can be used to select applicable critical experiments, to quantify a defensible margin to cover validation gaps and weaknesses, and in development of upper subcritical limits.

  16. Making Distance Visible: Assembling Nearness in an Online Distance Learning Programme

    Science.gov (United States)

    Ross, Jen; Gallagher, Michael Sean; Macleod, Hamish

    2013-01-01

    Online distance learners are in a particularly complex relationship with the educational institutions they belong to (Bayne, Gallagher, & Lamb, 2012). For part-time distance students, arrivals and departures can be multiple and invisible as students take courses, take breaks, move into independent study phases of a programme, find work or…

  17. Behind the Pay Gap

    Science.gov (United States)

    Dey, Judy Goldberg; Hill, Catherine

    2007-01-01

    Women have made remarkable gains in education during the past three decades, yet these achievements have resulted in only modest improvements in pay equity. The gender pay gap has become a fixture of the U.S. workplace and is so ubiquitous that many simply view it as normal. "Behind the Pay Gap" examines the gender pay gap for college graduates.…

  18. Phloem RNA-binding proteins as potential components of the long-distance RNA transport system.

    Directory of Open Access Journals (Sweden)

    VICENTE ePALLAS

    2013-05-01

    Full Text Available RNA-binding proteins (RBPs govern a myriad of different essential processes in eukaryotic cells. Recent evidence reveals that apart from playing critical roles in RNA metabolism and RNA transport, RBPs perform a key function in plant adaption to various environmental conditions. Long distance RNA transport occurs in land plants through the phloem, a conducting tissue that integrates the wide range of signalling pathways required to regulate plant development and response to stress processes. The macromolecules in the phloem pathway vary greatly and include defence proteins, transcription factors, chaperones acting in long distance trafficking, and RNAs (mRNAs, siRNAs and miRNAs. How these RNA molecules translocate through the phloem is not well understood, but recent evidence indicates the presence of translocatable RNA-binding proteins in the phloem, which act as potential components of long distance RNA transport system. This review updates our knowledge on the characteristics and functions of RBPs present in the phloem.

  19. Safety analysis for the Abadia de Goias repository: alternative evaluation of the ingestion dose rate critical distance; Analise de seguranca para o repositorio de Abadia de Goias: avaliacao alternativa da distancia critica de taxa de dose de ingestao

    Energy Technology Data Exchange (ETDEWEB)

    Martin Alves, A.S. de; Passos, E.M. dos [NUCLEN, Rio de Janeiro, RJ (Brazil)

    1995-12-31

    An alternative calculation of the ingestion dose rate critical distance due to a hypothetical release of Cs-137 from the structure of the Repository of Abadia de Goias is presented. The release pathway considers the repository - groundwater region - well - and food chain. The main adopted modification comparing to the previous work is the inclusion of the convective and molecular diffusion terms in the radionuclide transport equation in addition to the radioactive decay term. (author). 6 refs, 1 tab.

  20. Yield gap analysis in long-term experiments with intensive rice cultivation

    International Nuclear Information System (INIS)

    Laureles, E.V.; Correa, T. Jr.; Buresh, R.J.

    2007-01-01

    The long-term continuous cropping experiment at IRRI is cultivated with three rice crops in a year, making it the world's most intensively cropped long-term rice experiment. The availability of comprehensive rice production records, compiled weather data, and tested crop models provides a means to evaluate long-term trends in measured and potential yields and yield gaps in this rice production system. Yield trends were assessed using the highest yielding cultivar in each cropping season from 1979 to 2005. Potential yield of the highest yielding cultivar in each season was determined using three rice models (ORYZA, TERM, and CERES) run with the actual transplanting and harvest dates for the cultivar. The yield gap was determined from the difference between the simulated potential grain yield and the measured grain yield. Measured and potential yields and the yield gap varied across seasons and years. Measured yields were higher in the dry season than in the early and late wet seasons. The yield gap tended to be higher in the wet season than in the dry season. Climatic parameters, particularly solar radiation, influenced the performance of rice cultivars. The relatively larger yield gaps in the late wet season than in the dry season were associated with increased spikelet sterility. The cumulative measured yield for the three annual rice crop was near 80 percent of the annual yield potential in years with best practices for fertilizer N and crop management. The long term trends suggest that effective timing and rates of N fertilization and effective control of diseases were critical in achieving 80 percent of the annual yield potential

  1. Steiner Distance in Graphs--A Survey

    OpenAIRE

    Mao, Yaping

    2017-01-01

    For a connected graph $G$ of order at least $2$ and $S\\subseteq V(G)$, the \\emph{Steiner distance} $d_G(S)$ among the vertices of $S$ is the minimum size among all connected subgraphs whose vertex sets contain $S$. In this paper, we summarize the known results on the Steiner distance parameters, including Steiner distance, Steiner diameter, Steiner center, Steiner median, Steiner interval, Steiner distance hereditary graph, Steiner distance stable graph, average Steiner distance, and Steiner ...

  2. Increasing gap junctional coupling: a tool for dissecting the role of gap junctions

    DEFF Research Database (Denmark)

    Axelsen, Lene Nygaard; Haugan, Ketil; Stahlhut, Martin

    2007-01-01

    Much of our current knowledge about the physiological and pathophysiological role of gap junctions is based on experiments where coupling has been reduced by either chemical agents or genetic modification. This has brought evidence that gap junctions are important in many physiological processes....... In a number of cases, gap junctions have been implicated in the initiation and progress of disease, and experimental uncoupling has been used to investigate the exact role of coupling. The inverse approach, i.e., to increase coupling, has become possible in recent years and represents a new way of testing...... the role of gap junctions. The aim of this review is to summarize the current knowledge obtained with agents that selectively increase gap junctional intercellular coupling. Two approaches will be reviewed: increasing coupling by the use of antiarrhythmic peptide and its synthetic analogs...

  3. No Correlation between Distorted Body Representations Underlying Tactile Distance Perception and Position Sense

    Directory of Open Access Journals (Sweden)

    Matthew R. Longo

    2016-11-01

    Full Text Available Both tactile distance perception and position sense are believed to require that immediate afferent signals be referenced to a stored representation of body size and shape (the body model. For both of these abilities, recent studies have reported that the stored body representations involved are highly distorted, at least in the case of the hand, with the hand dorsum represented as wider and squatter than it actually is. Here, we investigated whether individual differences in the magnitude of these distortions are shared between tactile distance perception and position sense, as would be predicted by the hypothesis that a single distorted body model underlies both tasks. We used established task to measure distortions of the represented shape of the hand dorsum. Consistent with previous results, in both cases there were clear biases to overestimate distances oriented along the medio-lateral axis of the hand compared to the proximo-distal axis. Moreover, within each task there were clear split-half correlations, demonstrating that both tasks show consistent individual differences. Critically, however, there was no correlation between the magnitudes of distortion in the two tasks. This casts doubt on the proposal that a common body model underlies both tactile distance perception and position sense.

  4. Theoretical Principles of Distance Education.

    Science.gov (United States)

    Keegan, Desmond, Ed.

    This book contains the following papers examining the didactic, academic, analytic, philosophical, and technological underpinnings of distance education: "Introduction"; "Quality and Access in Distance Education: Theoretical Considerations" (D. Randy Garrison); "Theory of Transactional Distance" (Michael G. Moore);…

  5. THE DISTANCE TO M104

    Energy Technology Data Exchange (ETDEWEB)

    McQuinn, Kristen B. W. [University of Texas at Austin, McDonald Observatory, 2515 Speedway, Stop C1400 Austin, TX 78712 (United States); Skillman, Evan D. [Minnesota Institute for Astrophysics, School of Physics and Astronomy, 116 Church Street, SE, University of Minnesota, Minneapolis, MN 55455 (United States); Dolphin, Andrew E. [Raytheon Company, 1151 E. Hermans Road, Tucson, AZ 85756 (United States); Berg, Danielle [Center for Gravitation, Cosmology and Astrophysics, Department of Physics, University of Wisconsin Milwaukee, 1900 East Kenwood Boulevard, Milwaukee, WI 53211 (United States); Kennicutt, Robert, E-mail: kmcquinn@astro.as.utexas.edu [Institute for Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom)

    2016-11-01

    M104 (NGC 4594; the Sombrero galaxy) is a nearby, well-studied elliptical galaxy included in scores of surveys focused on understanding the details of galaxy evolution. Despite the importance of observations of M104, a consensus distance has not yet been established. Here, we use newly obtained Hubble Space Telescope optical imaging to measure the distance to M104 based on the tip of the red giant branch (TRGB) method. Our measurement yields the distance to M104 to be 9.55 ± 0.13 ± 0.31 Mpc equivalent to a distance modulus of 29.90 ± 0.03 ± 0.07 mag. Our distance is an improvement over previous results as we use a well-calibrated, stable distance indicator, precision photometry in a optimally selected field of view, and a Bayesian maximum likelihood technique that reduces measurement uncertainties. The most discrepant previous results are due to Tully–Fisher method distances, which are likely inappropriate for M104 given its peculiar morphology and structure. Our results are part of a larger program to measure accurate distances to a sample of well-known spiral galaxies (including M51, M74, and M63) using the TRGB method.

  6. The Distance to M51

    Science.gov (United States)

    McQuinn, Kristen. B. W.; Skillman, Evan D.; Dolphin, Andrew E.; Berg, Danielle; Kennicutt, Robert

    2016-07-01

    Great investments of observing time have been dedicated to the study of nearby spiral galaxies with diverse goals ranging from understanding the star formation process to characterizing their dark matter distributions. Accurate distances are fundamental to interpreting observations of these galaxies, yet many of the best studied nearby galaxies have distances based on methods with relatively large uncertainties. We have started a program to derive accurate distances to these galaxies. Here we measure the distance to M51—the Whirlpool galaxy—from newly obtained Hubble Space Telescope optical imaging using the tip of the red giant branch method. We measure the distance modulus to be 8.58 ± 0.10 Mpc (statistical), corresponding to a distance modulus of 29.67 ± 0.02 mag. Our distance is an improvement over previous results as we use a well-calibrated, stable distance indicator, precision photometry in a optimally selected field of view, and a Bayesian Maximum Likelihood technique that reduces measurement uncertainties. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained from the Data Archive at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555.

  7. Are contemporary tourists consuming distance?

    DEFF Research Database (Denmark)

    Larsen, Gunvor Riber

    2012. Background The background for this research, which explores how tourists represent distance and whether or not distance can be said to be consumed by contemporary tourists, is the increasing leisure mobility of people. Travelling for the purpose of visiting friends and relatives is increasing...... of understanding mobility at a conceptual level, and distance matters to people's manifest mobility: how they travel and how far they travel are central elements of their movements. Therefore leisure mobility (indeed all mobility) is the activity of relating across distance, either through actual corporeal...... metric representation. These representations are the focus for this research. Research Aim and Questions The aim of this research is thus to explore how distance is being represented within the context of leisure mobility. Further the aim is to explore how or whether distance is being consumed...

  8. Terminology report respect distance. The Use of the term respect distance in Posiva and SKB

    International Nuclear Information System (INIS)

    Lampinen, H.

    2007-09-01

    The term respect distance is used in some key publications of the Finnish Nuclear Waste Management Company, Posiva, and the Swedish Nuclear Waste Management Company, SKB (Svensk Kaernbrenslehantering). Posiva and SKB researchers use the same terms in their reports, and it is acknowledged that the terms used by both companies are not used in the same way, though the differences are often subtle. This report is a literature study of the term 'respect distance' and the terms immediately associated to it. Vital terms related to the respect distance and issues concerning the use of scale concepts in Posiva and SKB are gathered in the end of report. Posiva's respect distances consider the seismic, hydrological and mechanical properties of the deterministic deformation zones as important issues that constitute a risk for longterm safety. These requirements for respect distances are an interpretation of STUK's YVL 8.4 Guide. At present, Posiva's criteria regarding respect distances follow the instructions given in the Host Rock Classification system (HRC), whereas the size of a deformation zone to which respect distances are applied vary from the regional to local major and minor. This and other criteria that are given for respect distances may, however, change in the near future as Posiva's Rock Suitability Criteria (RSC) programme proceeds. SKB's considerations of respect distances acknowledge that the hydraulic and mechanical aspects of a deformation zone have an effect on the respect distance. However, the seismic risk is considered to overshadow the other effects on a regional scale. The respect distance defined for a deformation zone is coupled with the size of a fracture where secondary slip could occur. In the safety assessment it is assumed that this fracture cuts a deposition hole location. In SKB the respect distance is determined for regional and local major deformation zones. The trace length of such a zone is defined as being ≥ 3 km. For deformation zones

  9. New Maximal Two-distance Sets

    DEFF Research Database (Denmark)

    Lisonek, Petr

    1996-01-01

    A two-distance set in E^d is a point set X inthe d-dimensional Euclidean spacesuch that the distances between distinct points in Xassume only two different non-zero values. Based on results from classical distance geometry, we developan algorithm to classify, for a given dimension, all maximal...... (largest possible)two-distance sets in E^d.Using this algorithm we have completed the full classificationfor all dimensions less than or equal to 7, andwe have found one set in E^8 whosemaximality follows from Blokhuis' upper bound on sizes of s-distance sets.While in the dimensions less than or equal to 6...

  10. Gap and density theorems

    CERN Document Server

    Levinson, N

    1940-01-01

    A typical gap theorem of the type discussed in the book deals with a set of exponential functions { \\{e^{{{i\\lambda}_n} x}\\} } on an interval of the real line and explores the conditions under which this set generates the entire L_2 space on this interval. A typical gap theorem deals with functions f on the real line such that many Fourier coefficients of f vanish. The main goal of this book is to investigate relations between density and gap theorems and to study various cases where these theorems hold. The author also shows that density- and gap-type theorems are related to various propertie

  11. A two-center comparative study of gastric pull-up and jejunal interposition for long gap esophageal atresia

    NARCIS (Netherlands)

    Gallo, Gabriele; Zwaveling, S; Van Der Zee, David C.; Bax, Klaas N.; De Langen, Zacharias J.; Hulscher, Jan B F

    2015-01-01

    Purpose When restoration of the anatomical continuity in case of long gap esophageal atresia (LGEA) is not feasible, esophageal replacement surgery becomes mandatory. The aim of this paper is to critically compare the experience of two tertiary referral centers in The Netherlands performing either

  12. From the Kohn-Sham band gap to the fundamental gap in solids. An integer electron approach.

    Science.gov (United States)

    Baerends, E J

    2017-06-21

    It is often stated that the Kohn-Sham occupied-unoccupied gap in both molecules and solids is "wrong". We argue that this is not a correct statement. The KS theory does not allow to interpret the exact KS HOMO-LUMO gap as the fundamental gap (difference (I - A) of electron affinity (A) and ionization energy (I), twice the chemical hardness), from which it indeed differs, strongly in molecules and moderately in solids. The exact Kohn-Sham HOMO-LUMO gap in molecules is much below the fundamental gap and very close to the much smaller optical gap (first excitation energy), and LDA/GGA yield very similar gaps. In solids the situation is different: the excitation energy to delocalized excited states and the fundamental gap (I - A) are very similar, not so disparate as in molecules. Again the Kohn-Sham and LDA/GGA band gaps do not represent (I - A) but are significantly smaller. However, the special properties of an extended system like a solid make it very easy to calculate the fundamental gap from the ground state (neutral system) band structure calculations entirely within a density functional framework. The correction Δ from the KS gap to the fundamental gap originates from the response part v resp of the exchange-correlation potential and can be calculated very simply using an approximation to v resp . This affords a calculation of the fundamental gap at the same level of accuracy as other properties of crystals at little extra cost beyond the ground state bandstructure calculation. The method is based on integer electron systems, fractional electron systems (an ensemble of N- and (N + 1)-electron systems) and the derivative discontinuity are not invoked.

  13. Translational ethics? The theory-practice gap in medical ethics.

    Science.gov (United States)

    Cribb, Alan

    2010-04-01

    Translational research is now a critically important current in academic medicine. Researchers in all health-related fields are being encouraged not only to demonstrate the potential benefits of their research but also to help identify the steps through which their research might be 'made practical'. This paper considers the prospects of a corresponding movement of 'translational ethics'. Some of the advantages and disadvantages of focusing upon the translation of ethical scholarship are reviewed. While emphasising the difficulties of crossing the gap between scholarship and practice, the paper concludes that a debate about the business of translation would be useful for medical ethics.

  14. Distance learning

    Directory of Open Access Journals (Sweden)

    Katarina Pucelj

    2006-12-01

    Full Text Available I would like to underline the role and importance of knowledge, which is acquired by individuals as a result of a learning process and experience. I have established that a form of learning, such as distance learning definitely contributes to a higher learning quality and leads to innovative, dynamic and knowledgebased society. Knowledge and skills enable individuals to cope with and manage changes, solve problems and also create new knowledge. Traditional learning practices face new circumstances, new and modern technologies appear, which enable quick and quality-oriented knowledge implementation. The centre of learning process at distance learning is to increase the quality of life of citizens, their competitiveness on the workforce market and ensure higher economic growth. Intellectual capital is the one, which represents the biggest capital of each society and knowledge is the key factor for succes of everybody, who are fully aware of this. Flexibility, openness and willingness of people to follow new IT solutions form suitable environment for developing and deciding to take up distance learning.

  15. Board affiliation and pay gap

    Directory of Open Access Journals (Sweden)

    Shenglan Chen

    2014-06-01

    Full Text Available This paper examines the effects of board affiliation on the corporate pay gap. Using a sample of Chinese listed firms from 2005 to 2011, we find that boards with a greater presence of directors appointed by block shareholders have lower pay gaps. Furthermore, the governance effects of board affiliation with and without pay are distinguished. The empirical results show that board affiliation without pay is negatively related to the pay gap, while board affiliation with pay is positively related to the pay gap. Overall, the results shed light on how block shareholders affect their companies’ pay gaps through board affiliation.

  16. Mapping critical levels/loads for the Slovak Republic. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Zavodsky, D; Babiakova, G; Mitosinkova, M [and others

    1996-08-01

    As a part of the Agreement on Environmental Cooperation between Norway and Slovakia a project ``Mapping Critical Levels/Loads for Slovakia`` was established. This report presents the final project results. Critical loads for forest, surface and ground waters and their exceedances were calculated by means of the steady-state mass balance model PROFILE for soils, and the steady-state water chemistry method for waters. A grid distance of 10 km was used. Because the sulphur deposition has been decreasing, the exceedances of critical load of acidity and critical sulphur deposition of forest soils have decreased from 1990 to 1995. Practically no acidity exceedances for surface water or ground water were found in 1995. The critical level of forest ozone was exceeded all over Slovakia. In the Tatra mountains the exceedance was over 25000 ppb.h. 23 refs., 3 figs., 3 tabs.

  17. Azimuthal critical heat flux in narrow rectangular channels

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yong Hoon; Noh, Sang Woo; Kim, Sung Joong; Suh, Kune Y. [Seoul National University, Seoul (Korea, Republic of)

    2003-07-01

    Tests were conducted to examine the critical heat flux (CHF) on the one-dimensional downward heating rectangular channel having a narrow gap by changing the orientation of the copper test heater assembly in a pool of saturated water under the atmospheric pressure. The test parameters include both the gap sizes of 1, 2, 5 and 10mm, and the surface orientation angles from the downward-facing position (180{sup o}) to the vertical position (90{sup o}), respectively. Also, the CHF experiments were performed for pool boiling with varying heater surface orientations in the unconfined space at the atmospheric pressure using the rectangular test section. It was observed that the CHF generally decreases as the surface inclination angle increases and as the gap size decreases. In consistency with several studies reported in the literature, it was found that there exists a transition angle above which the CHF changes with a rapid slope. An engineering correlation is developed for the CHF during natural convective boiling in the inclined, confined rectangular channels with the aid of dimensional analysis.

  18. CZTS stoichiometry effects on the band gap energy

    International Nuclear Information System (INIS)

    Malerba, Claudia; Biccari, Francesco; Azanza Ricardo, Cristy Leonor; Valentini, Matteo; Chierchia, Rosa; Müller, Melanie; Santoni, Antonino; Esposito, Emilia; Mangiapane, Pietro; Scardi, Paolo; Mittiga, Alberto

    2014-01-01

    Highlights: • CZTS films with different compositions were grown from stacked-layer precursors. • The band-gap energy varies from 1.48 to 1.63 eV as the [Sn]/[Cu] ratio increases. • The Zn content seems not to be a critical parameter for the optical properties. • PDS data show an increase of the sub-gap absorption as the Sn content is reduced. • Formation of defects at low Sn content was proposed to explain the Eg variation. -- Abstract: The considerable spread of Cu 2 ZnSnS 4 (CZTS) optical properties reported in the literature is discussed in terms of material stoichiometry. To this purpose, kesterite thin films were prepared by sulfurization of multilayered precursors of ZnS, Cu and Sn, changing the relative amounts to obtain CZTS layers with different compositions. X-Ray Diffraction (XRD), Energy Dispersive X-Ray (EDX) spectroscopy, X-Ray Photoelectron Spectroscopy (XPS) and Raman spectroscopy were used for structural and compositional analysis. XRD quantitative phase analysis provides the amount of spurious phases and information on Sn-site occupancy. The optical properties were investigated by spectrophotometric and Photothermal Deflection Spectroscopy (PDS) measurements to assess the absorption coefficient of samples with different compositions. The PDS data show an increase of the sub-band absorption as the Sn content decreases. The results are interpreted assuming the formation of additional defects as the tin content is reduced. Those defects can also be responsible for the decrease of the band gap energy value as the Sn/Cu ratio is decreased

  19. Fast Exact Euclidean Distance (FEED): A new class of adaptable distance transforms

    NARCIS (Netherlands)

    Schouten, Theo E.; van den Broek, Egon

    2014-01-01

    A new unique class of foldable distance transforms of digital images (DT) is introduced, baptized: Fast Exact Euclidean Distance (FEED) transforms. FEED class algorithms calculate the DT starting directly from the definition or rather its inverse. The principle of FEED class algorithms is

  20. Fast Exact Euclidean Distance (FEED) : A new class of adaptable distance transforms

    NARCIS (Netherlands)

    Schouten, Theo E.; van den Broek, Egon L.

    2014-01-01

    A new unique class of foldable distance transforms of digital images (DT) is introduced, baptized: Fast Exact Euclidean Distance (FEED) transforms. FEED class algorithms calculate the DT startingdirectly from the definition or rather its inverse. The principle of FEED class algorithms is introduced,

  1. Distance covariance for stochastic processes

    DEFF Research Database (Denmark)

    Matsui, Muneya; Mikosch, Thomas Valentin; Samorodnitsky, Gennady

    2017-01-01

    The distance covariance of two random vectors is a measure of their dependence. The empirical distance covariance and correlation can be used as statistical tools for testing whether two random vectors are independent. We propose an analog of the distance covariance for two stochastic processes...

  2. Changes in the limb kinematics and walking-distance estimation after shank elongation : evidence for a locomotor body schema?

    NARCIS (Netherlands)

    Dominici, Nadia; Daprati, Elena; Nico, Daniele; Cappellini, Germana; Ivanenko, Yuri P; Lacquaniti, Francesco

    When walking, step length provides critical information on traveled distance along the ongoing path [corrected] Little is known on the role that knowledge about body dimensions plays within this process. Here we directly addressed this question by evaluating whether changes in body proportions

  3. Managing Time, Workload and Costs in Distance Education: Findings from a Literature Review of "Distances et Médiations des Savoirs" (Formerly "Distances et Savoirs")

    Science.gov (United States)

    Moeglin, Pierre; Vidal, Martine

    2015-01-01

    The purpose of this review, spanning over 12 years of publication of "Distances et Médiations des Savoirs" ("DMS"), formerly "Distance et Savoirs" ("DMS") (2003-2014), is guided by the question why and how French-speaking researchers addressed the issues of time, workload and costs in distance learning, and…

  4. The Adaptation Finance Gap Report

    DEFF Research Database (Denmark)

    UNEP’s Adaptation Gap Report series focuses on Finance, Technology and Knowledge gaps in climate change adaptation. It compliments the Emissions Gap Report series, and explores the implications of failing to close the emissions gap. The report builds on a 2014 assessment by the United Nations...... Environment Programme (UNEP), which laid out the concept of ‘adaptation gaps’ and outlined three such gaps: technology, finance and knowledge. The 2016 Adaptation Gap Report assesses the difference between the financial costs of adapting to climate change in developing countries and the amount of money...... actually available to meet these costs – a difference known as the “adaptation finance gap”. Like the 2014 report, the 2016 report focuses on developing countries, where adaptation capacity is often the lowest and needs the highest, and concentrates on the period up to 2050. The report identifies trends...

  5. A diffusive atmospheric pressure glow discharge in a coaxial pin-to-ring gap with a transverse magnetic field

    Directory of Open Access Journals (Sweden)

    YongSheng Wang

    2017-09-01

    Full Text Available Atmospheric pressure glow discharge (APGD has been widely used in the industrial field. The industrial applications are based on achieving stable and diffusive APGD in a relatively large space. The existing sources only achieved stable and diffusive APGD between a short inter-electrode distance within 5 millimeters. In this paper, the effect of a transverse stationary magnetic field on the diffusion of filamentary APGD was studied in a pin-to-ring coaxial gap. The APGD was driven by a high-voltage resonant power supply, and the stationary magnetic field was supplied by a permanent magnet. The stable and diffusive APGD was achieved in the circular area, which diameter was 20 millimeters. The experimental results revealed that more collision ionization occurred and the plasma was distributed diffusively in the discharge gap by applying the external transverse magnetic field. Besides, it is likely to obtain more stable and diffusive APGD in the coaxial pin-to-ring discharge gap when adjusting the input voltage, transverse magnetic flux density and resonant frequency of the power supply.

  6. Critical Knowledge Gaps in Our Understanding of Environmental Cycling and Transmission of Leptospira spp.

    Science.gov (United States)

    Barragan, Veronica; Olivas, Sonora; Keim, Paul; Pearson, Talima

    2017-10-01

    Exposure to soil or water contaminated with the urine of Leptospira -infected animals is the most common way in which humans contract leptospirosis. Entire populations can be at high risk of leptospirosis while working in inundated fields, when engaging in aquatic sports, or after periods of heavy rainfall. The risk of infection after contact with these environmental sources depends on the ability of Leptospira bacteria to survive, persist, and infect new hosts. Multiple variables such as soil and water pH, temperature, and even environmental microbial communities are likely to shape the environmental conditions needed by the pathogen to persist. Here we review what is known about the environmental phase of the infectious Leptospira transmission cycle and identify knowledge gaps that will serve as a guide for future research. Copyright © 2017 Barragan et al.

  7. Gap length distributions by PEPR

    International Nuclear Information System (INIS)

    Warszawer, T.N.

    1980-01-01

    Conditions guaranteeing exponential gap length distributions are formulated and discussed. Exponential gap length distributions of bubble chamber tracks first obtained on a CRT device are presented. Distributions of resulting average gap lengths and their velocity dependence are discussed. (orig.)

  8. Connecting long distance: semantic distance in analogical reasoning modulates frontopolar cortex activity.

    Science.gov (United States)

    Green, Adam E; Kraemer, David J M; Fugelsang, Jonathan A; Gray, Jeremy R; Dunbar, Kevin N

    2010-01-01

    Solving problems often requires seeing new connections between concepts or events that seemed unrelated at first. Innovative solutions of this kind depend on analogical reasoning, a relational reasoning process that involves mapping similarities between concepts. Brain-based evidence has implicated the frontal pole of the brain as important for analogical mapping. Separately, cognitive research has identified semantic distance as a key characteristic of the kind of analogical mapping that can support innovation (i.e., identifying similarities across greater semantic distance reveals connections that support more innovative solutions and models). However, the neural substrates of semantically distant analogical mapping are not well understood. Here, we used functional magnetic resonance imaging (fMRI) to measure brain activity during an analogical reasoning task, in which we parametrically varied the semantic distance between the items in the analogies. Semantic distance was derived quantitatively from latent semantic analysis. Across 23 participants, activity in an a priori region of interest (ROI) in left frontopolar cortex covaried parametrically with increasing semantic distance, even after removing effects of task difficulty. This ROI was centered on a functional peak that we previously associated with analogical mapping. To our knowledge, these data represent a first empirical characterization of how the brain mediates semantically distant analogical mapping.

  9. Simulating Interface Growth and Defect Generation in CZT – Simulation State of the Art and Known Gaps

    Energy Technology Data Exchange (ETDEWEB)

    Henager, Charles H. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Gao, Fei [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hu, Shenyang Y. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lin, Guang [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Bylaska, Eric J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Zabaras, Nicholas [Cornell Univ., Ithaca, NY (United States)

    2012-11-01

    This one-year, study topic project will survey and investigate the known state-of-the-art of modeling and simulation methods suitable for performing fine-scale, fully 3-D modeling, of the growth of CZT crystals at the melt-solid interface, and correlating physical growth and post-growth conditions with generation and incorporation of defects into the solid CZT crystal. In the course of this study, this project will also identify the critical gaps in our knowledge of modeling and simulation techniques in terms of what would be needed to be developed in order to perform accurate physical simulations of defect generation in melt-grown CZT. The transformational nature of this study will be, for the first time, an investigation of modeling and simulation methods for describing microstructural evolution during crystal growth and the identification of the critical gaps in our knowledge of such methods, which is recognized as having tremendous scientific impacts for future model developments in a wide variety of materials science areas.

  10. Critical sizes of light-water moderated UO2 and PuO2-UO2 lattices

    International Nuclear Information System (INIS)

    Tsuruta, Harumichi; Kobayashi, Iwao; Suzuki, Takenori; Ohno, Akio; Murakami, Kiyonobu

    1978-02-01

    Experimental critical sizes are presented for a total of about 250 lattices with 2.6 w/o UO 2 and 3.0 w/o PuO 2 -natural UO 2 fuel rods. The moderator was H 2 O and water-to-fuel volume ratios in the lattice cells ranged from 1.50 to 3.00 in the UO 2 lattices and from 2.42 to 5.55 in the PuO 2 -UO 2 lattices. The critical sizes were determined with the number of the fuel rods and a water level which were required to make the lattice critical in the shape of a rectangular parallelepiped over the temperature range from room temperature to 80 0 C. Reactivity variations of the PuO 2 -UO 2 lattices due to decaying of 241 Pu to 241 Am were traced during 3 years. Some critical sizes of the UO 2 and PuO 2 -UO 2 lattices with a water gap and of the UO 2 lattices with liquid poison in the moderator are also reported. Some physics parameters, such as the temperature coefficient of reactivity, the water-level worth, the reflector saving, the ratio between a migration area and an infinite multiplication factor and the critical buckling, are shown in relation to the critical sizes of the unperturbed lattices without the water gap and liquid poison. (auth.)

  11. Equivalence of massive propagator distance and mathematical distance on graphs

    International Nuclear Information System (INIS)

    Filk, T.

    1992-01-01

    It is shown in this paper that the assignment of distance according to the massive propagator method and according to the mathematical definition (length of minimal path) on arbitrary graphs with a bound on the degree leads to equivalent large scale properties of the graph. Especially, the internal scaling dimension is the same for both definitions. This result holds for any fixed, non-vanishing mass, so that a really inequivalent definition of distance requires the limit m → 0

  12. Language distance and tree reconstruction

    International Nuclear Information System (INIS)

    Petroni, Filippo; Serva, Maurizio

    2008-01-01

    Languages evolve over time according to a process in which reproduction, mutation and extinction are all possible. This is very similar to haploid evolution for asexual organisms and for the mitochondrial DNA of complex ones. Exploiting this similarity, it is possible, in principle, to verify hypotheses concerning the relationship among languages and to reconstruct their family tree. The key point is the definition of the distances among pairs of languages in analogy with the genetic distances among pairs of organisms. Distances can be evaluated by comparing grammar and/or vocabulary, but while it is difficult, if not impossible, to quantify grammar distance, it is possible to measure a distance from vocabulary differences. The method used by glottochronology computes distances from the percentage of shared 'cognates', which are words with a common historical origin. The weak point of this method is that subjective judgment plays a significant role. Here we define the distance of two languages by considering a renormalized edit distance among words with the same meaning and averaging over the two hundred words contained in a Swadesh list. In our approach the vocabulary of a language is the analogue of DNA for organisms. The advantage is that we avoid subjectivity and, furthermore, reproducibility of results is guaranteed. We apply our method to the Indo-European and the Austronesian groups, considering, in both cases, fifty different languages. The two trees obtained are, in many respects, similar to those found by glottochronologists, with some important differences as regards the positions of a few languages. In order to support these different results we separately analyze the structure of the distances of these languages with respect to all the others

  13. Language distance and tree reconstruction

    Science.gov (United States)

    Petroni, Filippo; Serva, Maurizio

    2008-08-01

    Languages evolve over time according to a process in which reproduction, mutation and extinction are all possible. This is very similar to haploid evolution for asexual organisms and for the mitochondrial DNA of complex ones. Exploiting this similarity, it is possible, in principle, to verify hypotheses concerning the relationship among languages and to reconstruct their family tree. The key point is the definition of the distances among pairs of languages in analogy with the genetic distances among pairs of organisms. Distances can be evaluated by comparing grammar and/or vocabulary, but while it is difficult, if not impossible, to quantify grammar distance, it is possible to measure a distance from vocabulary differences. The method used by glottochronology computes distances from the percentage of shared 'cognates', which are words with a common historical origin. The weak point of this method is that subjective judgment plays a significant role. Here we define the distance of two languages by considering a renormalized edit distance among words with the same meaning and averaging over the two hundred words contained in a Swadesh list. In our approach the vocabulary of a language is the analogue of DNA for organisms. The advantage is that we avoid subjectivity and, furthermore, reproducibility of results is guaranteed. We apply our method to the Indo-European and the Austronesian groups, considering, in both cases, fifty different languages. The two trees obtained are, in many respects, similar to those found by glottochronologists, with some important differences as regards the positions of a few languages. In order to support these different results we separately analyze the structure of the distances of these languages with respect to all the others.

  14. ETHICAL ISSUES IN OPEN AND DISTANCE EDUCATION WITH SPECIAL REFERENCE TO EXPECTATIONS AND REALITY

    Directory of Open Access Journals (Sweden)

    S. N. Vikram RAJ URS

    2013-10-01

    Full Text Available Education is intimately connected with ethics, because holistically speaking education is more than simply passing examinations and acquiring degrees. Education is character building and life long learning. Savants and philosophers throughout the history of humankind have borne testimony to this aspect of education. Today, there is a great deal of emphasis on continuous and life long learning which implies that education is a continual learning process and not merely relegated to certification. Our experience in the field of distance education indicates that the profile of distance learners varies, cutting across barriers of gender, class and caste. The distance learner may be suffering from a sense of isolation as he/she makes a return to study after a gap of time or while working. It is there that the distance educator makes a positive, ethical and interventionist role by helping the student to learn beyond the stereotypical classroom situation and can act effectively as the friend, philosopher and guide of the learner. Thus practicing what you preach is the moto of ethics in distance. Some of the more important ethical concerns associated with open and distance learning are not those that may be faced by learners. Instead, the challenges faced by those that design ODL or use it in their teaching can be seen as increasingly important. These challenges include globalization, which has emphasized instrumental rather than social aims of education, and the use of cognitive rather than affective pedagogies. For ODL designers and teachers, this has resulted in a concentration on cognitive tasks and market-driven aspects of open and distance learning at the expense of the social harmony that might otherwise be achieved. The overarching ethical concern for ODL practitioners should be to implement an appropriate pedagogy that will satisfy both instrumental and social aims. While this can be achieved, in part, through the use of the pedagogies outlined

  15. Generalized parton distributions and rapidity gap survival in exclusive diffractive pp scattering

    Energy Technology Data Exchange (ETDEWEB)

    Leonid Frankfurt; Charles Hyde-Wright; Mark Strikman; Christian Weiss

    2007-03-01

    We propose a new approach to the problem of rapidity gap survival (RGS) in the production of high-mass systems (H = dijet, heavy quarkonium, Higgs boson) in double-gap exclusive diffractive pp scattering, pp-->p + (gap) + H + (gap) + p. It is based on the idea that hard and soft interactions proceed over widely different time- and distance scales and are thus approximately independent. The high-mass system is produced in a hard scattering process with exchange of two gluons between the protons. Its amplitude is calculable in terms of the gluon generalized parton distributions (GPDs) in the protons, which can be measured in J= production in exclusive ep scattering. The hard scattering process is modified by soft spectator interactions, which we calculate in a model-independent way in terms of the pp elastic scattering amplitude. Contributions from inelastic intermediate states are suppressed. A simple geometric picture of the interplay of hard and soft interactions in diffraction is obtained. The onset of the black-disk limit in pp scattering at TeV energies strongly suppresses diffraction at small impact parameters and is the main factor in determining the RGS probability. Correlations between hard and soft interactions (e.g. due to scattering from the long-range pion field of the proton, or due to possible short-range transverse correlations between partons) further decrease the RGS probability. We also investigate the dependence of the diffractive cross section on the transverse momenta of the final-state protons (''diffraction pattern''). By measuring this dependence one can perform detailed tests of the interplay of hard and soft interactions, and even extract information about the gluon GPD in the proton. Such studies appear to be feasible with the planned forward detectors at the LHC.

  16. Generalized parton distributions and rapidity gap survival in exclusive diffractive pp scattering

    International Nuclear Information System (INIS)

    Leonid Frankfurt; Charles Hyde-Wright; Mark Strikman; Christian Weiss

    2006-01-01

    We propose a new approach to the problem of rapidity gap survival (RGS) in the production of high-mass systems (H = dijet, heavy quarkonium, Higgs boson) in double-gap exclusive diffractive pp scattering, pp-->p + (gap) + H + (gap) + p. It is based on the idea that hard and soft interactions proceed over widely different time- and distance scales and are thus approximately independent. The high-mass system is produced in a hard scattering process with exchange of two gluons between the protons. Its amplitude is calculable in terms of the gluon generalized parton distributions (GPDs) in the protons, which can be measured in J= production in exclusive ep scattering. The hard scattering process is modified by soft spectator interactions, which we calculate in a model-independent way in terms of the pp elastic scattering amplitude. Contributions from inelastic intermediate states are suppressed. A simple geometric picture of the interplay of hard and soft interactions in diffraction is obtained. The onset of the black-disk limit in pp scattering at TeV energies strongly suppresses diffraction at small impact parameters and is the main factor in determining the RGS probability. Correlations between hard and soft interactions (e.g. due to scattering from the long-range pion field of the proton, or due to possible short-range transverse correlations between partons) further decrease the RGS probability. We also investigate the dependence of the diffractive cross section on the transverse momenta of the final-state protons (''diffraction pattern''). By measuring this dependence one can perform detailed tests of the interplay of hard and soft interactions, and even extract information about the gluon GPD in the proton. Such studies appear to be feasible with the planned forward detectors at the LHC

  17. Gap Analysis Bulletin No. 13

    Science.gov (United States)

    2005-12-01

    we would like to web developer; gather comments from GAP researchers and data users. We are * facilitate collaboration among GAP projects by...N.Y. Research Grant #012/01 A. 42 Gap Analysis Bulletin No. 13, December 2005 Ga pAnalysis Smith, S. D., W. A. Brown, C. R. Smith, and M. E. Richmond... GAP will be focusing activities have greatly reduced the habitat available to support on the enduring features of the Great Lakes basin. Influences

  18. The Critical Turn in Tourism Studies; Creating an academy of hope

    NARCIS (Netherlands)

    Ateljevic, I.; Morgan, N.; Pritchard, A.

    2011-01-01

    In today’s increasingly complex tourism environment, decision-making requires a rounded, well-informed view of the whole. Critical distance should be encouraged, consultation and intellectual rigour should be the norm amongst managers and there needs to be a radical shift in our approach to

  19. Interactive Distance Learning in Connecticut.

    Science.gov (United States)

    Pietras, Jesse John; Murphy, Robert J.

    This paper provides an overview of distance learning activities in Connecticut and addresses the feasibility of such activities. Distance education programs have evolved from the one dimensional electronic mail systems to the use of sophisticated digital fiber networks. The Middlesex Distance Learning Consortium has developed a long-range plan to…

  20. Experimental Test Of Whether Electrostatically Charged Micro-organisms And Their Spores Contribute To The Onset Of Arcs Across Vacuum Gaps

    Energy Technology Data Exchange (ETDEWEB)

    none,; Grisham, Larry R.

    2014-02-24

    Recently it was proposed [L.R. Grisham, A. vonHalle, A.F. Carpe, Guy Rossi, K.R. Gilton, E.D. McBride, E.P. Gilson, A. Stepanov, T.N. Stevenson, Physics of Plasma 19 023107 (2012)] that one of the initiators of vacuum voltage breakdown between condu cting electrodes might be micro-organisms and their spores, previously deposited during exposure to air, which tnen become electrostatically charged when an electric potential is applied across the vacuum gap. The note describes a simple experiment to compare the number of voltage-conditioning pulses required to reach the nominal maxium operating voltage across a gap between two metallic conductors in a vacuum, comparing cases in which biological cleaning was done just prior to pump-down with cases where this was not done, with each preceded by exposure to ambient air for three days. Based upon these results, it does not appear that air-deposited microbes and their spores constitute a major pathway for arc initiation, at least for exposure periods of a few days, and for vacuum gaps of a few millimeters, in the regime where voltage holding is usually observed to vary linearly with gap distance