A remark on the half-linear extension of the Hartman-Wintner theorem

Directory of Open Access Journals (Sweden)

Ondrej Dosly

2000-07-01

Full Text Available We establish a Hartman-Wintner type theorem for the half-linear second order differential equation $$ (r(tPhi_p(x''+c(tPhi_p(x=0,quad Phi_p(x:=|x|^{p-2}x.$$ This equation is viewed as a perturbation of the non-oscillatory equation $$ (r(tPhi_p(x''+ilde c(tPhi_p(x=0 $$ with $ilde c(te 0$ eventually.

Hartman effect in a Kane-type semiconductor quantum ring

International Nuclear Information System (INIS)

Cakmaktepe, S

2007-01-01

The Hartman effect for a tunnelling particle implies that group delay time is independent of the opaque barrier width. In the present study, the tunnelling delay time in the transmission mode is studied taking into account the real band structure of an InSb-type semiconductor quantum ring and compared with that of a parabolic band structure. The system considered in this study consists of a circular loop in the presence of Aharonov-Bohm flux. It is shown that while tunnelling through an opaque barrier, the group delay time for a given incident energy becomes independent of the barrier thickness as well as the magnitude of the flux

On the generalized Hartman effect for symmetric double-barrier point potentials

International Nuclear Information System (INIS)

Lee, Molly A; Manzoni, Luiz A; Nyquist, Erik A; Lunardi, José T

2015-01-01

We consider the scattering of a non-relativistic particle by a symmetrical arrangement of two identical barriers in one-dimension, with the barriers given by the well-known four-parameter family of point interactions. We calculate the phase time and the stationary Salecker-Wigner-Peres clock time for the particular cases of a double δ and a double δ' barrier and investigate the off-resonance behavior of these time scales in the limit of opaque barriers, addressing the question of emergence of the generalized Hartman effect

Tunnelling through two successive barriers and the Hartman (superluminal) effect

International Nuclear Information System (INIS)

Olkhovsky, V.; Recami, E.; Salesi, G.; Bergamo Univ., Bergamo

2000-03-01

The paper studies the phenomenon of one-dimensional non-resonant tunnelling through two successive potential barriers, separated by an intermediate free region R, by analyzing the relevant solutions to the Schroedinger equation. The total traversal time does not depend not only on the barrier widths (the so called Hartman effect), but also on the R width: so the effective velocity in the region R, between the two barriers, can be regarded as infinite. This agrees with the results known from the corresponding waveguide experiments, which simulated the tunnelling experiment herein considered due to the formal identity between the Schroedinger and the Helmholtz equation

Rullierinereis imajimai nom. nov., a replacement name for R. profunda Imajima, 2009, secondary homonym to R. profunda (Hartman, 1965), formerly Namalycastis profundus.

Science.gov (United States)

Tanaka, Masaatsu; Sato, Masanori

2017-11-01

Hartman (1965) described a nereidid species, Namalycastis profundus[sic], based on a deep-sea specimen collected from off Bermuda (1000 m deep) in the NW Atlantic. Although Hartman (1965) did not mention its etymology, the specific name is believed to be derived from the Latin adjective "profund-" meaning "deep." Because Namalycastis is feminine in gender (Glasby et al. 2016), the original specific name as masculine was incorrect and must be corrected to N. profunda for mandatory gender agreement under Articles 31.2 and 34.2 of the International Code of Zoological Nomenclature (hereafter, "the Code") (International Commission of Zoological Nomenclature 1999).

Decrease of the tunneling time and violation of the Hartman effect for large barriers

International Nuclear Information System (INIS)

Olkhovsky, V.S.; Zaichenko, A.K.; Petrillo, V.

2004-01-01

The explicit formulation of the initial conditions of the definition of the wave-packet tunneling time is proposed. This formulation takes adequately into account the irreversibility of the wave-packet space-time spreading. Moreover, it explains the violations of the Hartman effect, leading to a strong decrease of the tunneling times up to negative values for wave packets with large momentum spreads due to strong wave-packet time spreading

Tunneling time, the Hartman effect, and superluminality: A proposed resolution of an old paradox

International Nuclear Information System (INIS)

Winful, Herbert G.

2006-01-01

The issue of tunneling time is replete with controversy and paradoxes. The controversy stems from the fact that many tunneling time definitions seem to predict superluminal tunneling velocities. One prediction, termed the Hartman effect, states that the tunneling time becomes independent of barrier length for thick enough barriers, ultimately resulting in unbounded tunneling velocities. Experiments done with 'single photons', classical light waves, and microwaves all show this apparent superluminality. The origin of these paradoxical effects has been a mystery for decades. In this article, we review the history of tunneling times starting with the early work of MacColl, Hartman, and Wigner. We discuss some of the tunneling time definitions, with particular emphasis on the phase time (also known as the group delay or Wigner time) and the dwell time. The key experiments are reviewed. We then discuss our recent work, which suggests that the group delay in tunneling is not a transit time as has been assumed for decades. It is, in reality, a lifetime and hence should not be used to assign a speed of barrier traversal. We show how this new understanding along with the concept of energy storage and release resolves all the outstanding tunneling time paradoxes

Dwell time, Hartman effect and transport properties in a ferromagnetic phosphorene monolayer.

Science.gov (United States)

Hedayati Kh, Hamed; Faizabadi, Edris

2018-02-28

In this paper, spin-dependent dwell time, spin Hartman effect and spin-dependent conductance were theoretically investigated through a rectangular barrier in the presence of an exchange field by depositing a ferromagnetic insulator on the phosphorene layer in the barrier region. The existence of the spin Hartman effect was shown for all energies (energies lower than barrier height) and all incident angles in phosphorene. We also compared our results of the dwell time in the phosphorene structure with similar research performed on graphene. We reported a significant difference between the tunneling time values of incident quasiparticles with spin-up and spin-down. We found that the barrier was almost transparent for incident quasiparticles with a wide range of incident angles and energies higher than the barrier height in phosphorene. We also found that the maximum spin-dependent transmission probability for energies higher than barrier height does not necessarily occur in the zero incident angle. In addition, we showed that the spin conductance for energies higher (lower) than barrier height fluctuates (decays) in terms of barrier thickness. We discovered that, in contrast to graphene, the Klein paradox does not occur in the normal incident in the phosphorene structure. Furthermore, the results demonstrated the achievement of good total conductance at certain thicknesses of the barrier for energies higher than the barrier height. This study could serve as a basis for investigations of the basic physics of tunneling mechanisms and also for using phosphorene as a spin polarizer in designing nanoelectronic devices.

Dwell time, Hartman effect and transport properties in a ferromagnetic phosphorene monolayer

Science.gov (United States)

Hedayati Kh, Hamed; Faizabadi, Edris

2018-02-01

In this paper, spin-dependent dwell time, spin Hartman effect and spin-dependent conductance were theoretically investigated through a rectangular barrier in the presence of an exchange field by depositing a ferromagnetic insulator on the phosphorene layer in the barrier region. The existence of the spin Hartman effect was shown for all energies (energies lower than barrier height) and all incident angles in phosphorene. We also compared our results of the dwell time in the phosphorene structure with similar research performed on graphene. We reported a significant difference between the tunneling time values of incident quasiparticles with spin-up and spin-down. We found that the barrier was almost transparent for incident quasiparticles with a wide range of incident angles and energies higher than the barrier height in phosphorene. We also found that the maximum spin-dependent transmission probability for energies higher than barrier height does not necessarily occur in the zero incident angle. In addition, we showed that the spin conductance for energies higher (lower) than barrier height fluctuates (decays) in terms of barrier thickness. We discovered that, in contrast to graphene, the Klein paradox does not occur in the normal incident in the phosphorene structure. Furthermore, the results demonstrated the achievement of good total conductance at certain thicknesses of the barrier for energies higher than the barrier height. This study could serve as a basis for investigations of the basic physics of tunneling mechanisms and also for using phosphorene as a spin polarizer in designing nanoelectronic devices.

The Art of ATLAS; multimedia installation by Neal Hartman and Claudia Marcelloni at Thinktank science museum in Birmingham, UK.

CERN Multimedia

Claudia Marcelloni

2010-01-01

The Art of ATLAS is an multimedia installation, developed by Neal Hartman and Claudia Marcelloni about the physicists, engineers and technicians behind the ATLAS Experiment. The installation will been shown at Planetarium entrance of the Thinktank science museum in Birmingham, UK from October 2010 until January 2011.

Tunneling times and the Hartman effect revisited

International Nuclear Information System (INIS)

Olkhovsky, Vladislav S.; Recami, Erasmo; Raciti, Fabio

1995-05-01

In a recent review paper we proposed, within conventional quantum mechanics, new definitions for the sub-barrier tunnelling and reflection times. Aims of the present paper are: presenting and analysing the results of various numerical calculations (based on our equations) on the penetration and return times , , during tunneling inside a rectangular potential barrier, for various penetration depths x f ; putting forth and discussing suitable definitions, besides of the mean values, also of the variances (or dispersions) D τ T D τ R for the time durations of transmission and reflection process; mentioning that our definition τ T > for the average transmission time results to constitute an improvement of the ordinary dwell-time τ Dw formula; commenting upon some recent criticism by C.R. Leavens, on the basis of our new numerical results. We stress that our numerical evaluations confirm that our approach implied and implies, the existence of the Hartman effect: an effect that in these days (due to the theoretical connections between tunneling and evanescent wave propagation) is receiving - at Cologne, Berkeley, Florence and Vienna- indirect, but quite interesting, experimental verifications. At last, we briefly analyze some other definitions of tunnelling times. (author). 24 refs., 5 figs

Conductance and Hartman effect of light and heavy holes in hetero structures semiconducting

International Nuclear Information System (INIS)

Arias Lazo, S.; Diago-Cisneros, L.

2008-01-01

Calculations of conductance (G) for a double barrier resonant behavior are presented (DBRT, n = 2) and for a supergrid (n> 2 cells), in the case of uncoupled holes. Evidence of the Hartman effect can also be obtained or a finite value of the momentum parallel to the interfaces (kT = 0, coupled holes). The numerical calculations were carried out using semiconductor III-V. As a theoretical model to obtain and interpret the results we used the dispersive approximation multicomponent (MSA). Within the framework of the MSA are calculated Landauer double-electrode conductance and phase time. There are resonant peaks in the oscillations of G to n = 2 cells in the absence of mixture of holes (kT≈ 0), that it can be considered giants with respect to the environment. This responds to Interferential States - known as resonance type Fano, to match the incident energy with quantum well embedded in the DBRT discrete levels and of which we have obtained evidence to KT = 0. Other behaviors, which have already been reported in the absence of mixing [2.5], remain robust with strong coupling and interference between channels. The MSA provides evidence of classical prediction of Hartman for values of the incident energy below the barrier with a strong coupling of light and heavy holes. At energies above the barrier is observed that resonant oscillations of the Ramsauer-Townsend of mild behavior to the 02 phase time, occur strongly disturbed at KT = 0. However, confirms the criticism on the quasi - linearity of time of tunneling by Heberle et al, and which has been widely discussed.

Huviharidus ei ole ainult soe bussipeatus / Piret Hartman, Ardo Rohtla, Annely Köster ... [jt.] ; intervjueerinud Maris Hellrand

Index Scriptorium Estoniae

2016-01-01

Noorte huvitegevuse toetussüsteemi kontseptsioon toob järgmisel sügisel valdkonda lisaraha. Vestlusringis huvihariduse probleemide üle osalesid kultuuriministri nõunik Piret Hartman, haridus- ja teadusministeeriumi noorteosakonna asejuhataja Ardo Rohtla, Sally Stuudio juhataja Annely Köster, Eesti Muusikakoolide Liidu juhatuse esimees Kadri Leivategija, Rakvere abilinnapea Kairit Pihlak, Eesti Teadushuvihariduse Liidu juhatuse liige Heilo Altin ja MTÜ Loovkirjutamise Keskus juhatuse liige Katriin Fisch-Uibopuu

Hartman effect and weak measurements that are not really weak

International Nuclear Information System (INIS)

Sokolovski, D.; Akhmatskaya, E.

2011-01-01

We show that in wave packet tunneling, localization of the transmitted particle amounts to a quantum measurement of the delay it experiences in the barrier. With no external degree of freedom involved, the envelope of the wave packet plays the role of the initial pointer state. Under tunneling conditions such ''self-measurement'' is necessarily weak, and the Hartman effect just reflects the general tendency of weak values to diverge, as postselection in the final state becomes improbable. We also demonstrate that it is a good precision, or a 'not really weak' quantum measurement: no matter how wide the barrier d, it is possible to transmit a wave packet with a width σ small compared to the observed advancement. As is the case with all weak measurements, the probability of transmission rapidly decreases with the ratio σ/d.

Tunneling times and the Hartman effect revisited

Energy Technology Data Exchange (ETDEWEB)

Olkhovsky, Vladislav S. [Ukrainian Academy of Sciences, Kiev (Ukraine). Inst. for Nuclear Research]|[Istituto Nazionale di Fisica Nucleare, Catania (Italy); Recami, Erasmo [Universidade Estadual de Campinas, SP (Brazil). Dept. de Matematica Aplicada]|[Istituto Nazionale di Fisica Nucleare, Milano (Italy); Raciti, Fabio [Catania Univ. (Italy). Dipt. di Fisica; Zaichenko, Aleksandr K. [Ukrainian Academy of Sciences, Kiev (Ukraine)

1995-05-01

In a recent review paper we proposed, within conventional quantum mechanics, new definitions for the sub-barrier tunnelling and reflection times. Aims of the present paper are: presenting and analysing the results of various numerical calculations (based on our equations) on the penetration and return times < {tau}Pen >, <{tau}Ret >, during tunneling inside a rectangular potential barrier, for various penetration depths x{sub f}; putting forth and discussing suitable definitions, besides of the mean values, also of the variances (or dispersions) D {sup {tau}}T D {sup {tau}}R for the time durations of transmission and reflection process; mentioning that our definition < {sup {tau}}T > for the average transmission time results to constitute an improvement of the ordinary dwell-time {tau}{sup Dw} formula; commenting upon some recent criticism by C.R. Leavens, on the basis of our new numerical results. We stress that our numerical evaluations confirm that our approach implied and implies, the existence of the Hartman effect: an effect that in these days (due to the theoretical connections between tunneling and evanescent wave propagation) is receiving - at Cologne, Berkeley, Florence and Vienna- indirect, but quite interesting, experimental verifications. At last, we briefly analyze some other definitions of tunnelling times. (author). 24 refs., 5 figs.

A novel Hartman Shack-based topography system: repeatability and agreement for corneal power with Scheimpflug+Placido topographer and rotating prism auto-keratorefractor.

Science.gov (United States)

Prakash, Gaurav; Srivastava, Dhruv; Choudhuri, Sounak

2015-12-01

The purpose of this study is to analyze the repeatability and agreement of corneal power using a new Hartman type topographer in comparison to Scheimpflug+Placido and autorefractor devices. In this cross sectional, observational study performed at the cornea services of a specialty hospital, 100 normal eyes (100 consecutive candidates) without any previous ocular surgery or morbidity except refractive error were evaluated. All candidates underwent three measurements each on a Full gradient, Hartman type topographer (FG) (iDesign, AMO), Scheimpflug+Placido topographer (SP) (Sirius, CSO) and rotating prism auto-keratorefractor (AR) (KR1, Nidek). The parameters assessed were flat keratometry (K1), steep keratometry (K2), steep axis (K2 axis), mean K, J 0 and J 45. Intra-device repeatability and inter-device agreement were evaluated. On repeatability analysis, the intra-device means were not significantly different (ANOVA, p > 0.05). Intraclass correlations (ICC) were >0.98 except for J 0 and J 45. In terms of intra-measurement standard deviation (Sw), the SP and FG groups fared better than AR group (p 0.05, R (2) 0.05). ICC ranged from 0.92 to 0.99 (p < 0.001). Regression fits on Bland-Altman plots suggested no clinically significant effect of average values over difference in means. The repeatability of Hartman type topographer in normal eyes is comparable to SP combination device and better than AR. The agreement between the three devices is good. However, we recommend against interchanging these devices between follow-ups or pooling their data.

Tunneling time and Hartman effect in a ferromagnetic graphene superlattice

Directory of Open Access Journals (Sweden)

Farhad Sattari

2012-03-01

Full Text Available Using transfer-matrix and stationary phase methods, we study the tunneling time (group delay time in a ferromagnetic monolayer graphene superlattice. The system we peruse consists of a sequence of rectangular barriers and wells, which can be realized by putting a series of electronic gates on the top of ferromagnetic graphene. The magnetization in the two ferromagnetic layers is aligned parallel. We find out that the tunneling time for normal incident is independent of spin state of electron as well as the barrier height and electron Fermi energy while for the oblique incident angles the tunneling time depends on the spin state of electron and has an oscillatory behavior. Also the effect of barrier width on tunneling time is also investigated and shown that, for normal incident, the Hartman effect disappears in a ferromagnetic graphene superlattice but it appears for oblique incident angles when the x component of the electron wave vector in the barrier is imaginary.

First European record of Haliclona loosanoffi Hartman, 1958 (Porifera, Haplosclerida), a species hitherto known only from the New England coast (U.S.A.)

NARCIS (Netherlands)

Soest, van R.W.M.

1976-01-01

An encrusting gemmuliferous haliclonid species is described from the Oosterschelde (S.W.- part of the Netherlands), which is demonstrated to be conspecific with Haliclona loosanoffi Hartman, 1958. This species was hitherto only known from the New England coast (U.S.A.). The species is compared with

Analysis of NMR spectra of sugar chains of glycolipids by multiple relayed COSY and 2D homonuclear Hartman-Hahn spectroscopy

International Nuclear Information System (INIS)

Inagaki, F.; Kohda, D.; Kodama, C.; Suzuki, A.

1987-01-01

The authors applied multiple relayed COSY and 2D homonuclear Hartman-Hahn spectroscopy to globoside, a glycolipid purified from human red blood cells. The subspectra corresponding to individual sugar components were extracted even from overlapping proton resonances by taking the cross sections of 2D spectra parallel to the F 2 axis at anomeric proton resonances, so that unambiguous assignments of sugar proton resonances were accomplished. (Auth.)

A novel adjuvant to the resident selection process: the hartman value profile.

Science.gov (United States)

Cone, Jeffrey D; Byrum, C Stephen; Payne, Wyatt G; Smith, David J

2012-01-01

The goal of resident selection is twofold: (1) select candidates who will be successful residents and eventually successful practitioners and (2) avoid selecting candidates who will be unsuccessful residents and/or eventually unsuccessful practitioners. Traditional tools used to select residents have well-known limitations. The Hartman Value Profile (HVP) is a proven adjuvant tool to predicting future performance in candidates for advanced positions in the corporate setting. No literature exists to indicate use of the HVP for resident selection. The HVP evaluates the structure and the dynamics of an individual value system. Given the potential impact, we implemented its use beginning in 2007 as an adjuvant tool to the traditional selection process. Experience gained from incorporating the HVP into the residency selection process suggests that it may add objectivity and refinement in predicting resident performance. Further evaluation is warranted with longer follow-up times.

Spin-dependent delay time and Hartman effect in asymmetrical graphene barrier under strain

Science.gov (United States)

Sattari, Farhad; Mirershadi, Soghra

2018-01-01

We study the spin-dependent tunneling time, including group delay and dwell time, in a graphene based asymmetrical barrier with Rashba spin-orbit interaction in the presence of strain, sandwiched between two normal leads. We find that the spin-dependent tunneling time can be efficiently tuned by the barrier width, and the bias voltage. Moreover, for the zigzag direction strain although the oscillation period of the dwell time does not change, the oscillation amplitude increases by increasing the incident electron angle. It is found that for the armchair direction strain unlike the zigzag direction the group delay time at the normal incidence depends on the spin state of electrons and Hartman effect can be observed. In addition, for the armchair direction strain the spin polarization increases with increasing the RSOI strength and the bias voltage. The magnitude and sign of spin polarization can be manipulated by strain. In particular, by applying an external electric field the efficiency of the spin polarization is improved significantly in strained graphene, and a fully spin-polarized current is generated.

Generality of the Hartman and Fletcher effect for the mean tunneling time in nonrelativistic particle and photon tunnelling without absorption and dissipation

International Nuclear Information System (INIS)

Jakiel, J.; Olkhovsky, V.S.

1998-01-01

It is known that, under certain conditions, the tunnelling time becomes independent of barrier width (the Hartman and Fletcher effect). Here, the generality of this effect is shown for mean tunnelling times in all known nonrelativistic approaches, in the cases of rectangular potential barriers without absorption and dissipation. On the base of this effect and the reshaping phenomenon, taking the analogy between nonrelativistic-particle and photon tunnelling into, account, one can self-consistently explain the observed superluminal effective (group) velocities in various photon tunnelling experiments without violation of the Einstein causality

Päästeamet tunnustas elupäästjaid ja jagas aumärke / Reimo Raja

Index Scriptorium Estoniae

Raja, Reimo

2010-01-01

2010. a. septembris autasutas siseminister Marko Pomerants ja Päästeameti peadirektor elupäästjaid. Pikemalt päästeoperatsioonidest, kus päästjateks olid Mehis Kont, Aleksei Rožkov, Kertu Rannak, Georg Alema, Hanna-Maria Puhke, Merit Kalamägi, Toomas Pagil, Janek Lember, Maiken Nelis, Markku Eklund, Olaf Orgs, Eduard Borovik, Vadim Kaminski, Eduard Bemidas, Ants Viirmann, Olesja Nekrassova, Konstantin Fjodorov, Ramid Niftalyev, Konstantin Gerassimov, Tarvo Turja, Aleksander Beljajev, Kalle Närska, Margus Matto, Igor Koževnikov, Vyacheslav Didenko, Boriss Mihhejev, Alexander Berezko, Aleksander Küttim, Andrei Larin, Aleksandr Bolšakov, Andrei Põld

76 FR 40439 - Qualification of Drivers; Exemption Applications; Diabetes Mellitus

Science.gov (United States)

2011-07-08

... proliferative diabetic retinopathy. He holds a Class A CDL from Nebraska. Johnathan R. Hartman Mr. Hartman, 31... certifies that Mr. Hartman understands diabetes management and monitoring, has stable control of his diabetes using insulin, and is able to drive a CMV safely. Mr. Hartman meets the requirements of the vision...

Portræt af litteraturkritikeren som ungt menneske

DEFF Research Database (Denmark)

Schatz-Jakobsen, Claus

2004-01-01

Artiklen præsenterer den amerikanske litteraturkritiker Geoffrey Hartmans tidlige forfatterskab og fremdrager dets selvbiografiske undertekst som nødvendig effekt af den unge Hartmans fascination af den engelske romantiker William Wordsworths forfatterskab.......Artiklen præsenterer den amerikanske litteraturkritiker Geoffrey Hartmans tidlige forfatterskab og fremdrager dets selvbiografiske undertekst som nødvendig effekt af den unge Hartmans fascination af den engelske romantiker William Wordsworths forfatterskab....

76 FR 58076 - International Security Advisory Board (ISAB) Meeting Notice; Closed Meeting

Science.gov (United States)

2011-09-19

... information, contact Richard W. Hartman II, Executive Director of the International Security Advisory Board..., 2011. Richard W. Hartman II, Executive Director, International Security Advisory Board, U.S. Department...

76 FR 81005 - International Security Advisory Board (ISAB) Meeting Notice; Closed Meeting

Science.gov (United States)

2011-12-27

.... For more information, contact Richard W. Hartman II, Executive Director of the International Security..., 2011. Richard W. Hartman II, Executive Director, International Security Advisory Board, U.S. Department...

78 FR 41183 - International Security Advisory Board (ISAB) Meeting Notice; Closed Meeting

Science.gov (United States)

2013-07-09

..., nuclear proliferation, and diplomacy. For more information, contact Richard W. Hartman II, Executive..., telephone: (202) 736-4290. Dated: June 26, 2013. Richard W. Hartman, II, Executive Director, International...

77 FR 47162 - International Security Advisory Board (ISAB) Meeting Notice; Closed Meeting

Science.gov (United States)

2012-08-07

... security, nuclear proliferation, and diplomacy. For more information, contact Richard W. Hartman II... 20520, telephone: (202) 736-4290. Dated: July 31, 2012. Richard W. Hartman, II, Executive Director...

76 FR 36167 - International Security Advisory Board (ISAB) Meeting Notice; Closed Meeting

Science.gov (United States)

2011-06-21

..., international security, nuclear proliferation, and diplomacy. For more information, contact Richard W. Hartman..., DC 20520, telephone: (202) 736-4290. Dated: June 13, 2011. Richard W. Hartman, II., Executive...

78 FR 51266 - International Security Advisory Board (ISAB) Meeting Notice

Science.gov (United States)

2013-08-20

... security, nuclear proliferation, and diplomacy. For more information, contact Richard W. Hartman II... 20520, telephone: (202) 736-4290. Dated: August 7, 2013. Richard W. Hartman, II, Executive Director...

75 FR 31327 - Airworthiness Directives; The Boeing Company Model 757 Airplanes

Science.gov (United States)

2010-06-03

... in the AD docket shortly after receipt. FOR FURTHER INFORMATION CONTACT: Chris Hartman, Aerospace.... Send information to ATTN: Chris Hartman, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle...

77 FR 21142 - International Security Advisory Board (ISAB) Meeting Notice; Closed Meeting

Science.gov (United States)

2012-04-09

..., international security, nuclear proliferation, and diplomacy. For more information, contact Richard W. Hartman..., DC 20520, telephone: (202) 736-4290. Dated: March 28, 2012. Richard W. Hartman II, Executive Director...

78 FR 66984 - International Security Advisory Board (ISAB); Meeting Notice; Closed Meeting

Science.gov (United States)

2013-11-07

... information, contact Richard W. Hartman II, Executive Director of the International Security Advisory Board, U.... Richard W. Hartman, II, Executive Director, International Security Advisory Board, U.S. Department of...

78 FR 33146 - Importance of Clear Safety Procedures for Temporary Removal From Service of Highway-Rail Grade...

Science.gov (United States)

2013-06-03

... Safety Advisory 2002-01. FOR FURTHER INFORMATION CONTACT: George Hartman, Staff Director, Signal and...., Washington, DC 20590 (phone: 202-493- 6225, email: George.Hartman@dot.gov ), or Kathryn Shelton, Trial...

75 FR 41278 - Notice of Final Federal Agency Actions on Proposed Highway in Idaho

Science.gov (United States)

2010-07-15

.... Peter J. Hartman, Division Administrator, Federal Highway Administration, 3050 Lake Harbor Lane, Suite... this program.) Authority: 23 U.S.C. 139(l)(1). Peter J. Hartman, Division Administrator, FHWA--Idaho...

27 CFR 9.77 - Altus.

Science.gov (United States)

2010-04-01

...) Hartman Quadrangle, 1961. (4) Hunt Quadrangle, 1963. (5) Watalula Quadrangle, 1973. (c) Boundary—(1... eastward to the crossing over Horsehead Creek (on the Hartman Quadrangle map). (ii) From there northward...

76 FR 46356 - Notice of Final Federal Agency Actions on Proposed Highway in Idaho

Science.gov (United States)

2011-08-02

.... Hartman, Division Administrator, Federal Highway Administration, 3050 Lake Harbor Lane, Suite 126, Boise... programs and activities apply to this program.) Authority: 23 U.S.C. 139(I)(1). Peter J. Hartman, Division...

75 FR 3782 - Notice of Final Federal Agency Actions on Interstate 84 Highway in Idaho

Science.gov (United States)

2010-01-22

... shorter time period still applies. FOR FURTHER INFORMATION CONTACT: For FHWA: Mr. Peter Hartman, Division... program.) Authority: 23 U.S.C. 139(l)(1). Peter J. Hartman, Division Administrator, FHWA--Idaho Division...

77 FR 74837 - President's Council of Advisors on Science and Technology (PCAST)

Science.gov (United States)

2012-12-18

... week of the meeting. Questions about the meeting should be directed to Dr. Amber Hartman Scholz, PCAST... accommodation to access this public meeting should contact Dr. Amber Hartman Scholz at least ten business days...

Plaadid / Valner Valme

Index Scriptorium Estoniae

Valme, Valner, 1970-

2005-01-01

Uutest heliplaatidest Client "City", Focuza "Inner Monologue EP" (eesti drum'n'bass muusiku heliplaat inglise firmalt), Pan American "Quiet City", Johnny Hartman, Johnny "Hartman For Lovers", John Frusciante, Josh Klinghoffer "A Sphere In The Heart"

77 FR 67805 - Applications for Eligibility Designation; Programs Under Parts A and F of Title III of the Higher...

Science.gov (United States)

2012-11-14

... Hartman, Institutional Service, U.S. Department of Education, 1990 K Street NW., room 6134, Request for.... Jeffrey.Hartman@ed.gov , 202-502-7607. If you use a telecommunications device for the deaf (TDD) or a text...

Identification key to Nephtyidae (Annelida of the Sea of Okhotsk

Directory of Open Access Journals (Sweden)

Inna L. Alalykina

2017-07-01

Full Text Available Currently, 15 species of Nephtyidae (Annelida are known from the Sea of Okhotsk (north-western Pacific. A new user-friendly identification key is presented with a brief description for each species. The taxonomic positions of three closely related species, Nephtys brachycephala Moore, 1903, N. schmitti Hartman, 1938 and N. paradoxa Malm, 1874, are revised. The distributions of two species, Nephtys discors Ehlers, 1968 and N. assignis Hartman, 1950, are discussed.

A faster 1.375-approximation algorithm for sorting by transpositions.

Science.gov (United States)

Cunha, Luís Felipe I; Kowada, Luis Antonio B; Hausen, Rodrigo de A; de Figueiredo, Celina M H

2015-11-01

Sorting by Transpositions is an NP-hard problem for which several polynomial-time approximation algorithms have been developed. Hartman and Shamir (2006) developed a 1.5-approximation [Formula: see text] algorithm, whose running time was improved to O(nlogn) by Feng and Zhu (2007) with a data structure they defined, the permutation tree. Elias and Hartman (2006) developed a 1.375-approximation O(n(2)) algorithm, and Firoz et al. (2011) claimed an improvement to the running time, from O(n(2)) to O(nlogn), by using the permutation tree. We provide counter-examples to the correctness of Firoz et al.'s strategy, showing that it is not possible to reach a component by sufficient extensions using the method proposed by them. In addition, we propose a 1.375-approximation algorithm, modifying Elias and Hartman's approach with the use of permutation trees and achieving O(nlogn) time.

Valimisaktiivsus viib sihile / Piret Hartman

Index Scriptorium Estoniae

Hartman, Piret

2002-01-01

Sotsiaalhoolekande seadusesse on sisse viidud muudatused, millest tulenevalt arvestatakse abiraha saamisel tudengid vanematega ühte leibkonda. Antud tingimuse tõttu kaob pea 10000 üliõpilasel võimalus majanduslikku abi saada

Origin of the Hartman effect

International Nuclear Information System (INIS)

Martinez, J.C.; Polatdemir, E.

2006-01-01

For thin barriers, we show that the tunneling time τ is linear in the width and gives the traversal time. For thick barriers, τ saturates through the suppression of all but the first reflection or transmission term and gives the time to penetrate to a characteristic depth. We discuss data from frustrated internal reflection experiments

Natural convection in square cavity filled with ferrofluid saturated porous medium in the presence of uniform magnetic field

Energy Technology Data Exchange (ETDEWEB)

Javed, Tariq [Department of Mathematics and Statistics, FBAS, International Islamic University, Islamabad 44000 (Pakistan); Mehmood, Z., E-mail: rajaziafat@yahoo.com [Department of Mathematics and Statistics, FBAS, International Islamic University, Islamabad 44000 (Pakistan); Abbas, Z. [Department of Mathematics, The Islamia University, Bahawalpur (Pakistan)

2017-02-01

This article contains numerical results for free convection through square enclosure enclosing ferrofluid saturated porous medium when uniform magnetic field is applied upon the flow along x-axis. Heat is provided through bottom wall and a square blockage placed near left or right bottom corner of enclosure as a heat source. Left and right vertical boundaries of the cavity are considered insulated while upper wall is taken cold. The problem is modelled in terms of system of nonlinear partial differential equations. Finite element method has been adopted to compute numerical simulations of mathematical problem for wide range of pertinent flow parameters including Rayleigh number, Hartman number, Darcy number and Prandtl number. Analysis of results reveals that the strength of streamline circulation is an increasing function of Darcy and Prandtl number where convection heat transfer is dominant for large values of these parameters whereas increase in Hartman number has opposite effects on isotherms and streamline circulations. Thermal conductivity and hence local heat transfer rate of fluid gets increased when ferroparticles are introduced in the fluid. Average Nusselt number increases with increase in Darcy and Rayleigh numbers while it is decreases when Hartman number is increased.

Natural convection in square cavity filled with ferrofluid saturated porous medium in the presence of uniform magnetic field

International Nuclear Information System (INIS)

Javed, Tariq; Mehmood, Z.; Abbas, Z.

2017-01-01

This article contains numerical results for free convection through square enclosure enclosing ferrofluid saturated porous medium when uniform magnetic field is applied upon the flow along x-axis. Heat is provided through bottom wall and a square blockage placed near left or right bottom corner of enclosure as a heat source. Left and right vertical boundaries of the cavity are considered insulated while upper wall is taken cold. The problem is modelled in terms of system of nonlinear partial differential equations. Finite element method has been adopted to compute numerical simulations of mathematical problem for wide range of pertinent flow parameters including Rayleigh number, Hartman number, Darcy number and Prandtl number. Analysis of results reveals that the strength of streamline circulation is an increasing function of Darcy and Prandtl number where convection heat transfer is dominant for large values of these parameters whereas increase in Hartman number has opposite effects on isotherms and streamline circulations. Thermal conductivity and hence local heat transfer rate of fluid gets increased when ferroparticles are introduced in the fluid. Average Nusselt number increases with increase in Darcy and Rayleigh numbers while it is decreases when Hartman number is increased.

Relativistic tunneling through two successive barriers

International Nuclear Information System (INIS)

Lunardi, Jose T.; Manzoni, Luiz A.

2007-01-01

We study the relativistic quantum mechanical problem of a Dirac particle tunneling through two successive electrostatic barriers. Our aim is to study the emergence of the so-called generalized Hartman effect, an effect observed in the context of nonrelativistic tunneling as well as in its counterparts and which is often associated with the possibility of superluminal velocities in the tunneling process. We discuss the behavior of both the phase (or group) tunneling time and the dwell time, and show that in the limit of opaque barriers the relativistic theory also allows the emergence of the generalized Hartman effect. We compare our results with the nonrelativistic ones and discuss their interpretation

Influence of radial magnetic field on the peristaltic flow of Williamson fluid in a curved complaint walls channel

Directory of Open Access Journals (Sweden)

Tasawar Hayat

Full Text Available Peristaltic transport of Williamson fluid in a curved geometry is modeled. Problem formulation is completed by complaint walls of channel. Radial magnetic field in the analysis is taken into account. Resulting problem formulation is simplified using long wavelength and low Reynolds number approximations. Series solution is obtained for small Weissenberg number. Influences of different embedded parameters on the axial velocity and stream function are examined. As expected the velocity in curved channel is not symmetric. Axial velocity is noticed decreasing for Hartman number. Trapped bolus increases for Hartman and curvature parameters. Keywords: Williamson fluid, Curved channel, Radial magnetic field, Complaint walls

Tunneling time in space fractional quantum mechanics

Science.gov (United States)

Hasan, Mohammad; Mandal, Bhabani Prasad

2018-02-01

We calculate the time taken by a wave packet to travel through a classically forbidden region of space in space fractional quantum mechanics. We obtain the close form expression of tunneling time from a rectangular barrier by stationary phase method. We show that tunneling time depends upon the width b of the barrier for b → ∞ and therefore Hartman effect doesn't exist in space fractional quantum mechanics. Interestingly we found that the tunneling time monotonically reduces with increasing b. The tunneling time is smaller in space fractional quantum mechanics as compared to the case of standard quantum mechanics. We recover the Hartman effect of standard quantum mechanics as a special case of space fractional quantum mechanics.

Impact of chemical reaction in fully developed radiated mixed convective flow between two rotating disk

Science.gov (United States)

Hayat, T.; Khan, M. Waleed Ahmed; Khan, M. Ijaz; Waqas, M.; Alsaedi, A.

2018-06-01

Flow of magnetohydrodynamic (MHD) viscous fluid between two rotating disks is modeled. Angular velocities of two disks are different. Flow is investigated for nonlinear mixed convection. Heat transfer is analyzed for nonlinear thermal radiation and heat generation/absorption. Chemical reaction is also implemented. Convective conditions of heat and mass transfer are studied. Transformations used lead to reduction of PDEs into the ODEs. The impacts of important physical variables like Prandtl number, Reynold number, Hartman number, mixed convection parameter, chemical reaction and Schmidt number on velocities, temperature and concentration are elaborated. In addition velocity and temperature gradients are physically interpreted. Our obtained results indicate that radial, axial and tangential velocities decrease for higher estimation of Hartman number.

Conventional breeding strategies to enhance the sustainability of ...

African Journals Online (AJOL)

Conventional breeding strategies to enhance the sustainability of Musa biodiversity conservation for endemic cultivars. M Pillay, R Ssebuliba, J Hartman, D Vuylsteke, D Talengera, W Tushemereirwe ...

Hartman Testing of X-Ray Telescopes

Science.gov (United States)

Saha, Timo T.; Biskasch, Michael; Zhang, William W.

2013-01-01

Hartmann testing of x-ray telescopes is a simple test method to retrieve and analyze alignment errors and low-order circumferential errors of x-ray telescopes and their components. A narrow slit is scanned along the circumference of the telescope in front of the mirror and the centroids of the images are calculated. From the centroid data, alignment errors, radius variation errors, and cone-angle variation errors can be calculated. Mean cone angle, mean radial height (average radius), and the focal length of the telescope can also be estimated if the centroid data is measured at multiple focal plane locations. In this paper we present the basic equations that are used in the analysis process. These equations can be applied to full circumference or segmented x-ray telescopes. We use the Optical Surface Analysis Code (OSAC) to model a segmented x-ray telescope and show that the derived equations and accompanying analysis retrieves the alignment errors and low order circumferential errors accurately.

Hoolekandeasutustele ei sobi reorganiseerimiskava / Piret Hartman

Index Scriptorium Estoniae

Hartman, Piret

2005-01-01

Ilmunud ka Põhjarannik 23. märts lk. 2, Severnoje Poberezhje 23. märts lk. 2, Meie Maa 7. apr, lk. 2, Nädaline 7. apr. lk. 5, Teataja : Eestimaa Rahvaliidu Ajaleht Apr nr. 4 lk. 3. Riigikogu Rahvaliidu fraktsiooni nõunik sotsiaalfoorumist, kus osalesid hoolekandeasutuste ja kohalike omavalitsuste esindajad, Eesti Maaomavalitsuste Liidu juhatuse liikmed ning Riigikogu liikmed

Biblisch-koranische Figuren – feminin: Jesus, Joseph and Job Characters from the Bible and the Quran—Feminine: Jesus, Joseph and Job

Directory of Open Access Journals (Sweden)

Barbara Winckler

2003-07-01

Full Text Available Jesus, Joseph and Job stellt drei Texte aus der Feder zeitgenössischer libanesischer Autorinnen vor, die auf unterschiedliche Weise die Geschichten religiöser Figuren neu schreiben, und diskutiert sie im Hinblick auf ihr subversives Potential für gesellschaftlichen Wandel. Dazu werden in der Analyse neben der Intertextualität Konzepte genderorientierter und postkolonialer Ansätze wie métissage und borderlands herangezogen.In Jesus, Joseph and Job Hartman introduces three texts, written by contemporary Lebanese women authors who re-write the history of religious characters, and discusses these texts with respect to their subversive potential for societal change. In her analysis, Hartman does not only use intertextuality, but also gender-informed and post-colonial approaches such as, métissage and border spaces.

Complications associated with malnutrition in elective surgical ...

African Journals Online (AJOL)

Type of surgery. Breast. 16 (32). Simple mastectomy. Simple mastectomy with axillary clearance. Quadrantectomy with axillary clearance. Endocrine. 25 (50). Thyroidectomy. Parathyroidectomy. Adrenalectomy. GIT. 7 (14). Colectomy. Laparascopic cholecystectomy. Reversal of Hartman's procedure. Hernioplasty. Others.

Application of Discrete EventSimulation in Mine Production Forecast*

African Journals Online (AJOL)

Michael

2016-06-01

Jun 1, 2016 ... Mine production forecast is pertinent to mining as it serves production ... Besides the inability of this method to mimic the .... management and truck operators understood the ..... Mining Engineering Handbook, Hartman, H. L..

Africa Insight - Vol 42, No 2 (2012)

African Journals Online (AJOL)

Tourism and Transparency: Navigating Ethical Risks in Volunteerism with Fair Trade Learning · EMAIL FULL TEXT EMAIL FULL TEXT DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. E Hartman, CM Paris, B Blache-Cohen, 157-168 ...

[Nonlinear magnetohydrodynamics

International Nuclear Information System (INIS)

1992-01-01

Theoretical predictions were compared with available data from JET on the threshold unstable MHD activity in toroidal confinement devices. In particular, questions arising as to Hartmans number and the selection of a kinematic viscosity are discussed

Mass-Gathering Medical Care in Electronic Dance Music Festivals.

Science.gov (United States)

FitzGibbon, Kathleen M; Nable, Jose V; Ayd, Benjamin; Lawner, Benjamin J; Comer, Angela C; Lichenstein, Richard; Levy, Matthew J; Seaman, Kevin G; Bussey, Ian

2017-10-01

Introduction Electronic dance music (EDM) festivals represent a unique subset of mass-gathering events with limited guidance through literature or legislation to guide mass-gathering medical care at these events. Hypothesis/Problem Electronic dance music festivals pose unique challenges with increased patient encounters and heightened patient acuity under-estimated by current validated casualty predication models. This was a retrospective review of three separate EDM festivals with analysis of patient encounters and patient transport rates. Data obtained were inserted into the predictive Arbon and Hartman models to determine estimated patient presentation rate and patient transport rates. The Arbon model under-predicted the number of patient encounters and the number of patient transports for all three festivals, while the Hartman model under-predicted the number of patient encounters at one festival and over-predicted the number of encounters at the other two festivals. The Hartman model over-predicted patient transport rates for two of the three festivals. Electronic dance music festivals often involve distinct challenges and current predictive models are inaccurate for planning these events. The formation of a cohesive incident action plan will assist in addressing these challenges and lead to the collection of more uniform data metrics. FitzGibbon KM , Nable JV , Ayd B , Lawner BJ , Comer AC , Lichenstein R , Levy MJ , Seaman KG , Bussey I . Mass-gathering medical care in electronic dance music festivals. Prehosp Disaster Med. 2017;32(5):563-567.

Oscillations of first order difference equations

Indian Academy of Sciences (India)

Similarly, if yn < 0 for n ! N, then we may show that ... From Theorem 2 it follows that every solution of the equation oscillates. In particular, .... [2] Hartman P, Difference equations: Disconjugacy, principal solutions, Green's functions, complete ...

How Students with Visual Impairments Can Learn Components of the Expanded Core Curriculum through Physical Education

Science.gov (United States)

Lieberman, Lauren J.; Haegele, Justin A.; Columna, Luis; Conroy, Paula

2014-01-01

Research indicates that children with visual impairments demonstrate delays in fundamental motor skills, including locomotor, object control, and balance skills (Haibach, Lieberman, & Pritchett, 2011; Houwen, Hartman, & Visscher, 2010; Wagner, Haibach, & Lieberman, 2013). All of these skills are prerequisites to living an independent…

77 FR 67808 - President's Council of Advisors on Science and Technology (PCAST)

Science.gov (United States)

2012-11-14

...-secondary science, technology, engineering, and mathematics (STEM) education. PCAST will also receive an... only for substantive commentary on PCAST's work, not for business marketing purposes. Oral Comments: To.... Amber Hartman Scholz at least ten business days prior to the meeting so that appropriate arrangements...

78 FR 56730 - Notice of Intent To Amend the Resource Management Plan for the Gunnison Field Office and Prepare...

Science.gov (United States)

2013-09-13

... submit comments on issues and planning criteria related to Hartman Rocks Special Recreation Area... the scoping process; and seeks public input on issues and preliminary planning criteria. The planning... manner that maintains or improves the condition and health of the unique landscape and natural resources...

Physical activity in patients with Chronic Obstructive Pulmonary Disease

NARCIS (Netherlands)

Hartman, Jorine Elisabeth

2013-01-01

Betere beweegrichtlijnen nodig voor COPD-patiënt Bewegen is belangrijk, vooral voor patiënten met chronisch obstructieve longziekte (COPD). Toch zijn COPD-patiënten minder dan gemiddeld lichamelijk actief. Jorine Hartman onderzocht door welke fysieke en psychosociale factoren dat komt. Haar

A taxonomic study of sessile peritrichs (Ciliophora: Peritricha ...

African Journals Online (AJOL)

Three new and four known species of sessile peritrichs were identified from the crustacean ectoparasites, Lernaea barnimiana (Hartman, 1870), L. cyprinacea Linnaeus, 1758 and Dolops ranarum(Stuhimann, 1891) from various fish hosts in South Africa The new species described are: Epistylis cyprinaceae sp. n., ...

The Nature of the Learning Experiences of Leadership Coaches That Lead to Coaching Competencies: A Phenomenological Study

Science.gov (United States)

Backus, Clark R.

2018-01-01

This qualitative, phenomenological study addressed the research question: What is the nature of the learning experiences of leadership coaches that lead to coaching competency? With the increasing recognition of leadership coaching as a meaningful leadership development experience (Allen & Hartman, 2008; Maltbia, Marsick, & Ghosh, 2014;…

Oscillatory properties of solutions to certain two-dimensional systems of non-linear ordinary differential equations

Czech Academy of Sciences Publication Activity Database

Dosoudilová, M.; Lomtatidze, Alexander; Šremr, Jiří

2015-01-01

Roč. 120, June (2015), s. 57-75 ISSN 0362-546X Institutional support: RVO:67985840 Keywords : half-linear system * Hartman -Wintner theorem * Kamenev theorem Subject RIV: BA - General Mathematics Impact factor: 1.125, year: 2015 http://www.sciencedirect.com/science/article/pii/S0362546X15000620

Structural morphology of alkali feldspars and zircon and oriented intergrowths causing asterism in gemstones

NARCIS (Netherlands)

Woensdregt, C.F.

1990-01-01

Crystalline material grown in aqueous solutions or from vapour phase is often bounded by plane crystal faces. The surface configuration of such faces, that is controlled by the internal crystal structure, can be derived by the Hartman-Perdok theory with atomic precision. The crystal faces can be

Daniël 2 as satire

African Journals Online (AJOL)

23 Jan 2012 ... So ook Culley (1992:21) wat skryf: 'Like legend, biblical narrative ... Humphreys 1973:211; Collins 1975:219; Hartman & DiLella ..... Berger, P., 1997, Redeeming Laughter: The Comic Dimension of Human Experience, W. ... Heaton, E., 1956, The book of Daniel: Torch Bible Commentaries, SCM, London.

Biosurveillance in a Highly Mobile Population - Year 3

Science.gov (United States)

2012-07-01

provides an opportunity- rich tested for the impact upon infectious disease modeling, biosurveillance, and public health. Kulldorf et al (2005) assessed...Secular Circles and Millenial Trends. URSS, Moscow 2006 Kulldorff M, Heffernan R, Hartman J, Assunção RM, Mostashari F. (2005). “Space-Time Permutation

Simultaneous effects of slip and wall properties on MHD peristaltic motion of nanofluid with Joule heating

International Nuclear Information System (INIS)

Hayat, T.; Nisar, Z.; Ahmad, B.; Yasmin, H.

2015-01-01

This paper is devoted to the magnetohydrodynamic (MHD) peristaltic transport of nanofluid in a channel with wall properties. Flow analysis is addressed in the presence of viscous dissipation, partial slip and Joule heating effects. Mathematical modelling also includes the salient features of Brownian motion and thermophoresis. Both analytic and numerical solutions are provided. Comparison between the solutions is shown in a very good agreement. Attention is focused to the Brownian motion parameter, thermophoresis parameter, Hartman number, Eckert number and Prandtl number. Influences of various parameters on skin friction coefficient, Nusselt and Sherwood numbers are also investigated. It is found that both the temperature and nanoparticles concentration are increasing functions of Brownian motion and thermophoresis parameters. - Highlights: • Temperature rises when Brownian motion and thermophoresis effects intensify. • Temperature profile increases when thermal slip parameter increases. • Concentration field is a decreasing function of concentration slip parameter. • Temperature decreases whereas concentration increases for Hartman number

Simultaneous effects of slip and wall properties on MHD peristaltic motion of nanofluid with Joule heating

Energy Technology Data Exchange (ETDEWEB)

Hayat, T. [Department of Mathematics, Quaid-I-Azam University 45320, Islamabad 44000 (Pakistan); Nonlinear Analysis and Applied Mathematics (NAAM) Research Group, Department of Mathematics, King Abdulaziz University, P.O. Box 80257, Jeddah 21589 (Saudi Arabia); Nisar, Z. [Department of Mathematics, Quaid-I-Azam University 45320, Islamabad 44000 (Pakistan); Ahmad, B. [Nonlinear Analysis and Applied Mathematics (NAAM) Research Group, Department of Mathematics, King Abdulaziz University, P.O. Box 80257, Jeddah 21589 (Saudi Arabia); Yasmin, H., E-mail: qau2011@gmail.com [Department of Mathematics, COMSATS Institute of Information Technology, G.T. Road, Wah Cantt 47040 (Pakistan)

2015-12-01

This paper is devoted to the magnetohydrodynamic (MHD) peristaltic transport of nanofluid in a channel with wall properties. Flow analysis is addressed in the presence of viscous dissipation, partial slip and Joule heating effects. Mathematical modelling also includes the salient features of Brownian motion and thermophoresis. Both analytic and numerical solutions are provided. Comparison between the solutions is shown in a very good agreement. Attention is focused to the Brownian motion parameter, thermophoresis parameter, Hartman number, Eckert number and Prandtl number. Influences of various parameters on skin friction coefficient, Nusselt and Sherwood numbers are also investigated. It is found that both the temperature and nanoparticles concentration are increasing functions of Brownian motion and thermophoresis parameters. - Highlights: • Temperature rises when Brownian motion and thermophoresis effects intensify. • Temperature profile increases when thermal slip parameter increases. • Concentration field is a decreasing function of concentration slip parameter. • Temperature decreases whereas concentration increases for Hartman number.

Unified time analysis of photon and particle tunnelling

International Nuclear Information System (INIS)

Olkhovsky, V.S.; Recami, Erasmo; Jakiel, Jacek

2004-01-01

A unified time analysis of photon and nonrelativistic particle tunnellings is presented, in which time is regarded as a quantum observable, canonically conjugated to energy. Within this approach, one can introduce self-consistent definitions of the tunnelling times, on the basis of conventional quantum mechanics (or one-dimensional quantum electrodynamics) only. The validity of the Hartman effect [which states the tunnelling duration to be independent of the (opaque) barrier width, with superluminal group velocities of the tunnelling packet as a consequence] is verified for all the known expressions of the mean tunnelling time. However, some noticeable generalizations of (and deviations from) the Hartman effect are, as well, briefly investigated. Moreover, the analogy between particle and photon tunnelling is suitably exploited; on the basis of such an analogy, an explanation of some recent interesting microwave and optical experimental results on tunnelling times is proposed. Attention is devoted, at last, to some aspects of the causality problem for particle and photon tunnelling

Physical Activity and Motor Skills in Children with and without Visual Impairments

NARCIS (Netherlands)

Houwen, Suzanne; Hartman, Esther; Visscher, Chris

HOUWEN, S., E. HARTMAN, and C. VISSCHER. Physical Activity and Motor Skills in Children with and without Visual Impairments. Med. Sci. Sports Exerc., Vol. 41, No, 1, pp. 103-109, 2009. Purpose: To examine the physical activity levels of children with and without visual impairments(VI). We further

78 FR 59677 - Environmental Impacts Statements; Notice of Availability

Science.gov (United States)

2013-09-27

... Addition Project, Medicine Bow-Routt National Forests and Thunder Basin National Grassland, Review Period..., Final EIS, USFS, MT, Kootenai National Forest Land Management Plan Revision, Review Period Ends: 11/26... Transmission Lines on Forest Service Lands, Comment Period Ends: 11/12/2013, Contact: Jim Hartman 720-962-7255...

Many Seasons Gone: Memory, History, and the Atlantic Slave Trade

Directory of Open Access Journals (Sweden)

Ted Maris-Wolf

2009-07-01

Full Text Available [First paragraph] African Voices of the Atlantic Slave Trade: Beyond the Silence and the Shame. Anne C. Bailey. Boston: Beacon Press, 2005. 289 pp. (Cloth US $ 26.00 Lose Your Mother: A Journey along the Atlantic Slave Route. Saidiya Hartman. New York: Farrar, Straus and Giroux, 2007. xi + 270 pp. (Cloth US $ 25.00 In Two Thousand Seasons, the great Ghanaian novelist Ayi Kwei Armah describes the effects of centuries of European exploitation and violence in Africa and the alienation and death that separated Ghanaians in 1973 (when the book was published from those before them. “Pieces cut off from their whole are nothing but dead fragments,” he laments. “From the unending stream of our remembrance the harbingers of death break off meaningless fractions. Their carriers bring us this news of shards. Their message: behold this paltriness; this is all your history” (Armah 1973:2. It is this seeming paltriness, this history of meaningless fractions that Anne C. Bailey and Saidiya Hartman explore in their latest works, identifying and mending shards of memory and written and oral fragments into recognizable and meaningful forms. As with Armah in Two Thousand Seasons, for Bailey and Hartman, “the linking of those gone, ourselves here, those coming ... it is that remembrance that calls us” (Armah 1973:xiii. Both of them, haunted by remembrance and driven by a personal quest for reconciliation with the past and a scholarly desire for the truth, are unwilling to accept the past as passed, or to settle for the scattered silence that so often substitutes for the history of Africans and those of the diaspora.

Kõige eest siin elus tuleb maksta / Piret Hartman

Index Scriptorium Estoniae

Hartman, Piret

2006-01-01

ERL-i fraktsiooni nõunik käsitleb rahvastikuteadlase Kalev Katuse loengut Eesti rahvastikuarengust Euroopa kontekstis. Rahvastiku juurdekasv tuleb seada kõigis valdkondades esmatähtsaks, vaja on terviklikku toetussüsteemi kuni lapse täiskasvanuks saamiseni

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African Journals Online (AJOL)

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The gall bladder eventually collapses due to fibrosis while the terminal bile ducts become dilated. A calculus is usually found in the cystic duct or in the Hartman's pouch. This presents an unusual and specific cause of obstruction of the terminal bile ducts. Patients present with obstructive jaundice. Cholangiography shows ...

Letters in this Issue

Science.gov (United States)

1998-01-01

Reforming the General Chemistry Textbook individual letters by Edward T. Samulski; Stephen J. Hawkes; Stephen J. Fisher; J. Stephen Hartman; A. R. H. Cole; Stanley Pine, Ronald Archer, and Herbert Kaesz; Jimmy Reeves; Robert Hill; and Brock Spencer, C. Bradley Moore and Nedah Rose. Re: article by R. J. Gillespie The author replies

Tunneling times in bianisotropic, dispersive and absorptive metamaterials

International Nuclear Information System (INIS)

Radosavljević, Sanja; Radovanović, Jelena; Milanović, Vitomir

2016-01-01

Tunneling times in complex bianisotropic materials have been examined in detail, with absorption and dispersion taken into account. Tunneling is characterized by the dwell and the phase tunneling time. In this paper, we have developed a theoretical model and derived the appropriate expressions for each of these quantities, as well as a relationship between them and the corresponding expression for the energy density. The model has been verified through numerical calculations based on experimental data. We have distinguished cases in which the phases of transmitted and incident wave match each other, and showed that for small angles of incidence, the time that the wave spends inside the barrier can be approximated as a linear function of the barrier width. The Hartman effect has been detected, although for very thick layers of metamaterial. - Highlights: • We analyze the tunneling times in bianisotropic, dispersive and absorptive metamaterials. • Conditions of zero phase tunneling time are identified for a range of frequencies of interest. • The Hartman effect has been detected for very thick barriers of metamaterial.

Tunneling times in bianisotropic, dispersive and absorptive metamaterials

Energy Technology Data Exchange (ETDEWEB)

Radosavljević, Sanja [School of Electrical Engineering, University of Belgrade, Bulevar kralja Aleksandra 73, 11120 Belgrade (Serbia); Photonics Research Group, Ghent University – imec, Sint-Pietersnieuwstraat 41, 9000 Ghent (Belgium); Radovanović, Jelena, E-mail: radovanovic@etf.bg.ac.rs [School of Electrical Engineering, University of Belgrade, Bulevar kralja Aleksandra 73, 11120 Belgrade (Serbia); Milanović, Vitomir [School of Electrical Engineering, University of Belgrade, Bulevar kralja Aleksandra 73, 11120 Belgrade (Serbia)

2016-12-09

Tunneling times in complex bianisotropic materials have been examined in detail, with absorption and dispersion taken into account. Tunneling is characterized by the dwell and the phase tunneling time. In this paper, we have developed a theoretical model and derived the appropriate expressions for each of these quantities, as well as a relationship between them and the corresponding expression for the energy density. The model has been verified through numerical calculations based on experimental data. We have distinguished cases in which the phases of transmitted and incident wave match each other, and showed that for small angles of incidence, the time that the wave spends inside the barrier can be approximated as a linear function of the barrier width. The Hartman effect has been detected, although for very thick layers of metamaterial. - Highlights: • We analyze the tunneling times in bianisotropic, dispersive and absorptive metamaterials. • Conditions of zero phase tunneling time are identified for a range of frequencies of interest. • The Hartman effect has been detected for very thick barriers of metamaterial.

Comparison of the Relationship between Words Retained and Intelligence for Three Instructional Strategies among Students with Below-Average IQ

Science.gov (United States)

Burns, Matthew K.; Boice, Christina H.

2009-01-01

The current study replicated MacQuarrie, Tucker, Burns, and Hartman (2002) with a sample of 20 students who had been identified with a disability and had an IQ score that was between 1 and 3 standard deviations below the normative mean. Each student was taught 27 words from the Esperanto International Language with the following conditions: (a)…

Evolution of tunnelling causality and the 'Hartman-Fletcher effect'

International Nuclear Information System (INIS)

Olkhovsky, V.S.; Zaichenko, A.K.

1995-01-01

A new concept of the macroscopic tunneling time is added to our previous definition of the microscopic tunnelling time. The formally accusal jump of a time advance near the forward barrier wall is interpreted as a result of the superposition and interference of incoming and reflected waves. The reality 'H.-F. effect' is confirmed

Hartman-Wintner growth results for sublinear functional differential equations

Directory of Open Access Journals (Sweden)

John A. D. Appleby

2017-01-01

Full Text Available This article determines the rate of growth to infinity of scalar autonomous nonlinear functional and Volterra differential equations. In these equations, the right-hand side is a positive continuous linear functional of f(x. We assume f grows sublinearly, leading to subexponential growth in the solutions. The main results show that the solution of the functional differential equations are asymptotic to that of an auxiliary autonomous ordinary differential equation with right-hand side proportional to f. This happens provided f grows more slowly than l(x=x/log(x. The linear-logarithmic growth rate is also shown to be critical: if f grows more rapidly than l, the ODE dominates the FDE; if f is asymptotic to a constant multiple of l, the FDE and ODE grow at the same rate, modulo a constant non-unit factor; if f grows more slowly than l, the ODE and FDE grow at exactly the same rate. A partial converse of the last result is also proven. In the case when the growth rate is slower than that of the ODE, sharp bounds on the growth rate are determined. The Volterra and finite memory equations can have differing asymptotic behaviour and we explore the source of these differences.

On implementation of the EU – Ukraine / Dirk Hartman

Index Scriptorium Estoniae

Hartman, Dirk

2014-01-01

Euroopa Liidu ja selle liikmesriikide ning Ukraina vahelise assotsieerimislepingu rakendamisest (poliitiline dialoog; õigus, vabadus ja turvalisus; majanduslik koostöö; kaubandus; tuumaenergia ja taastuvad energiaallikad)

The application of homotopy analysis method for MHD viscous flow due to a shrinking sheet

International Nuclear Information System (INIS)

Sajid, M.; Hayat, T.

2009-01-01

This work is concerned with the magnetohydrodynamic (MHD) viscous flow due to a shrinking sheet. The cases of two dimensional and axisymmetric shrinking have been discussed. Exact series solution is obtained using the homotopy analysis method (HAM). The convergence of the obtained series solution is discussed explicitly. The obtained HAM solution is valid for all values of the suction parameter and Hartman number.

Is This Your Year to Inspire a Child? | Poster

Science.gov (United States)

By Julie Hartman, Guest Writer The Elementary Outreach Program (EOP) is looking for volunteers for the 2013–2014 school year. This program is designed to bring science into the classrooms of Frederick County students in grades 1 through 5. You’ll have a chance to work with small groups of children, presenting hands-on lessons that are coordinated with the school curriculum.

Time Series Analysis of Vegetation Change using Hyperspectral and Multispectral Data

Science.gov (United States)

2012-09-01

rivers clogged with sediment” (Hartman, 2008). In addition, backpackers, campers, and skiers are in danger of being hit by falling trees. Mountain...information from hyperspectral data without a priori knowledge or requiring ground observations” (Kruse & Perry, 2009). Figure 16. Spectral...known endmembers and the scene spectra (Boardman & Kruse, 2011). Known endmembers come from analysts’ knowledge of an area in a scene, or from

Implementation of an Electronic Medical Records System

Science.gov (United States)

2008-05-07

Hartman, MAJ Roddex Barlow , CPT Christopher Besser and Capt Michael Emerson...thank you I am truly honored to call each of you my friends. Electronic... abnormal findings are addressed. 18 Electronic Medical Record Implementation Barriers of the Electronic Medical Records System There are several...examination findings • Psychological and social assessment findings N. The system provides a flexible mechanism for retrieval of encounter

Make a movie in 48 hours

CERN Document Server

Brokk Toggerson

2011-01-01

This year, the 48-hour film project (48hfp) returns to Geneva after a one-year hiatus. Organized by Neal Hartman and the CERN film-making club, Open Your Eyes Films, the 48hfp challenges teams of film-makers to write, shoot, soundtrack and edit a 4 to 7 minute film in 48 hours from 4 to 6 November.   At the start of the festival, contestants picked their film genre from a hat. The films will be screened on 8 and 9 November, with the awards presentation on the 9th. The winner will receive a trip to the US to compete in the international version of the competition. “There are so many short films being made now," says Hartman, “I think, however, that the 48hfp allows a critical creative mass to form. The result is that these 20 teams make 20 better films than if each participant were making their own." Each team draws a genre from a hat and is given a character, a prop and a line of dialogue that must appear in their film. The genres run the gamut from &am...

Laminar Natural Convection in Square Enclosure Under an Externally Evanescent Magnetic Field

International Nuclear Information System (INIS)

El Jery, Atef; Ben Brahim, Ammar; Magherbi, Mourad

2009-01-01

This paper numerically investigates the effect of an externally evanescent magnetic field on flow patterns and heat transfer of fluid in a square cavity. The horizontal walls of the enclosure are assumed to be insulated while the vertical walls are kept isothermal. A control volume finite element method is used to solve the conservation equations at Prandtl number of 0.71. The effect of constant Hartman number on Nusselt number was studied. Validation tests with existing data demonstrate the aptitude of the present method to produce accurate results. The effects of magnetic field inclination angle from 0 degree to 90 degree on streamlines distributions are shown for different values of Hartman number. For Grashof number equal to 10 5 , the values of relaxation time of the magnetic field are chosen, so that the Lorentz force acts only in the transient state of Nusselt number in natural convection. The Nusselt number was calculated for different values of the inverse relaxation time varying from 0 to + ∞. The magnitude and the number of oscillations of the Nusselt number were observed. It has been found that no oscillation was seen at relaxation time equal to 20

Unsteady Magnetohydrodynamic Flow of Liquid Through a Channel Variable Pressure Gradient

International Nuclear Information System (INIS)

Singh, C.B.

1998-01-01

The article studies the unsteady motion of an electrically conducting, viscous incompressible fluid along a channel in the presence of imposed transverse magnetic field, when the walls do not conduct current, under the influence of pressure gradient which varies linearly with respect to time. Analytical expressions for the velocity of the fluid for various values of Hartman numbers and at different times has been obtained

Demonstration of Energy Savings in Commercial Buildings for Tiered Trim and Respond Method in Resetting Static Pressure for VAV Systems

Science.gov (United States)

2017-03-01

Technology Certification Program EUI Energy Use Intensity EW Energy and Water GHG Greenhouse Gas GSM Global System for Mobile GWh Gigawatt hours...utility bill. Other charges could include basic service charge, transmission service charge, on-peak and off-peak demand charges, and franchise fee...Regulated Air Volume (TRAV) systems. ASHRAE Transactions 99(1):791-800. 106 15. Hartman, T. 1995. Global optimization strategies for high

WHK Student Internship Enrollment, Mentor Participation Up More than 50 Percent | Poster

Science.gov (United States)

By Nancy Parrish, Staff Writer The Werner H. Kirsten Student Internship Program (WHK SIP) has enrolled the largest class ever for the 2013–2014 academic year, with 66 students and 50 mentors. This enrollment reflects a 53 percent increase in students and a 56 percent increase in mentors, compared to 2012–2013 (43 students and 32 mentors), according to Julie Hartman, WHK SIP

Reversing Maladaptive Plasticity to Cure Autonomic Dysreflexia after Spinal Cord Injury

Science.gov (United States)

2016-10-01

to elicit spinal autonomic reflexes as described previously [9]. The tips of Hartman hemostats were shielded with polyethylene tubing and then used...to the first click in every trial for 30 s. Colorectal distension was accomplished using a 4-French, 60 mm balloon- tipped catheter (Swan-Ganz...distension were used to elicit somatic or visceral-sympathetic reflexes below the level of injury. Such stimuli are potent induces of autonomic

Fish, Benthic-Macroinvertebrate, and Stream-Habitat Data From Two Estuaries Near Galveston Bay, Texas, 2000-2001

Science.gov (United States)

2002-01-01

0 0 0 1 0 2 0 0 0 2 5 Amphipoda Hyalellidae Hyalella azteca ( Saussure ) 0 0 16 0 0 0 0 0 0 0 16 Capitellida Capitellidae Mediomastus ambiseta (Hartman...0 0 0 0 0 0 0 0 14 0 14 Amphipoda Gammaridae Gammarus sp. 0 0 0 0 0 0 0 0 28 0 28 Amphipoda Hyalellidae Hyalella azteca ( Saussure ) 47 0 18 0 0 0 0 0

A Behavioual and Brain Science Perspective on Decision Making in Sport

OpenAIRE

Parkin, Beth Louise

2017-01-01

The elite athlete routinely performs impressive cognitive feats. Not only do they undertake complex decision-making seemingly intuitively, they do so under conditions of intense pressure, limited time and restricted resources. Decision-making refers to the cognitive processes that underpin the selection of one course of action from several alternatives (Reason, 1990); it is essential for high-quality performance in sport (Farrow & Raab, 2008; Jordet & Hartman, 2008; Paserman, 2007). Decision-...

Open Education Week Panel Discussion

OpenAIRE

Doolittle, Peter; Hart, Heath; Hartman, Greg; Seyam, Mohammed; Walz, Anita R.

2015-01-01

Introduction by Julie Speer, Associate Dean for Research & Informatics. Open remarks by Anita Walz, Assessment, Open Education & Online Learning Environments Librarian. Mohammed Seyam discusses the value of openly licensed material as a student, research, and graduate assistant. Heath Hart reflects on his adoption of an open educational resource and a (subscribed) online textbook in, “A Rousing Success and an Unmitigated Disaster.” Greg Hartman discusses his experiences authoring open-source ...

Ettevõtlik ülikool / Piret Hartman, Roomet Sõrmus, Aigar Aab

Index Scriptorium Estoniae

Hartman, Piret

2006-01-01

Eesti Maaülikooli üliõpilaskonna sihtasutus viis läbi projekti "Maamajandusettevõtete kaasamine EMÜ üliõpilaste õppetöösse". Kaheksateistkümnest ettevõtetesse läbi viidud ekskursioonist võttis osa neli- ja poolsada üliõpilast

Response to William T. Hartman: Funding Models for Special Education.

Science.gov (United States)

Sage, Daniel

1992-01-01

This response to EC 604 970 focuses on how costs of special education are to be shared among all applicable agencies. Controversy is noted in payment for services for such populations as preschool children, "aging-out" individuals, and individuals with severe disabilities. States are urged to consider these issues in fiscal policy development.…

The application of finite element method for mhd viscous flow over a porous stretching sheet

International Nuclear Information System (INIS)

Mahmood, R.; Sajid, M.

2007-01-01

This work is concerned with the magnetohydrodynamic (MHD) viscous flow due to a porous stretching sheet. The similarity solution of the problem is obtained using finite element method. The physical quantities of interest like the fluid velocity and skin friction coefficient is obtained and discussed under the influence of suction parameter and Hartman number. It is evident from the results that MHD can be used to control the boundary layer thickness. (author)

On Resisting Social Influence

Science.gov (United States)

1979-09-01

Eds.), Law , Justice and the individual in society: Psychological and legal issues. New York: Holt, Rinehart and Winston, 1977, 198-223. Hartman, J. J...Kadish, M. R., & Kadish, S. H. Discretion to disobey: A study of lawful departures from legal rules. Stanford, Calif.: Stanford University Press, Lifton, R...30 Stoner, C., & Parke, J. All God’s children. New York: Penguin, 1979. Szasz , T. Patty Hearst’s conversion: Some call it brainwashing. The New

The Association Between Molecular Markers in Colorectal Sessile Serrated Polyps and Colorectal Cancer Risk

Science.gov (United States)

2017-08-01

AWARD NUMBER: W81XWH-15-1-0273 TITLE: The Association between Molecular Markers in Colorectal Sessile Serrated Polyps and Colorectal Cancer ... Colorectal Cancer Risk 5a. CONTRACT NUMBER 5b. GRANT NUMBER W81XWH-15-1-0273 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Andrea Burnett-Hartman 5d... cancer in patients with sessile serrated colorectal polyps (SSPs). The project’s specific aims are as follows: 1) Estimate the risk of colorectal

Exponential Inequalities for Positively Associated Random Variables and Applications

Directory of Open Access Journals (Sweden)

Yang Shanchao

2008-01-01

Full Text Available Abstract We establish some exponential inequalities for positively associated random variables without the boundedness assumption. These inequalities improve the corresponding results obtained by Oliveira (2005. By one of the inequalities, we obtain the convergence rate for the case of geometrically decreasing covariances, which closes to the optimal achievable convergence rate for independent random variables under the Hartman-Wintner law of the iterated logarithm and improves the convergence rate derived by Oliveira (2005 for the above case.

Heat transfer analysis of GO-water nanofluid flow between two parallel disks

Directory of Open Access Journals (Sweden)

M. Azimi

2015-03-01

Full Text Available In this paper, the unsteady magnetohydrodynamic (MHD squeezing flow between two parallel disks (which is filled with nanofluid is considered. The Galerkin optimal homotopy asymptotic method (GOHAM is used to obtain the solution of the governing equations. The effects of Hartman number, nanoparticle volume fraction, Brownian motion parameter and suction/blowing parameter on nanofluid concentration, temperature and velocity profiles have been discussed. Furthermore, a comparison between obtained solutions and numerical ones have been provided.

Career exploration in Mozambique : exploratory study with secondary students

OpenAIRE

Ussene, Camilo; Taveira, Maria do Céu

2009-01-01

This article is part of a larger research project on the evaluation of career intervention needs in Mozambique. It consists of an exploratory study of the career exploration process of Mozambican students attending the 12th grade. The results of the construct validity and clustering analyses of the responses to the Career Exploration Survey (CES; Stumpf, Colarelli, & Hartman, 1983) are discussed, in the light of the career exploration theory and empirical research, namely the cognitive-motiva...

PSA-Based Screening Outcomes, Dietary Heterocyclic Amine Exposure, and Prostate Cancer Risk in African Americans

Science.gov (United States)

2008-06-01

was conducted specifically to determine whether meat intake or meat-related mutagens, including PhIP, was associated with increased PC risk ( Cross ... Cross et al., 2005). Other intakes were not found to be associated with increased PC risk. No separate analysis was done of study results by race...369. Block G., Hartman A.M., Dresser C.M., Carroll M.D., Gannon J., and Gardner L. A data-based approach to diet questionnaire design and testing. Am

Enhanced Interferometry with Programmable Spatial Light Modulator

Science.gov (United States)

2010-06-07

Interferometry, Spatial Light Modulator, Surface Accuracy, Optics, Mirror, Zernike , Freeform Optics, Null Testing, Hartman, Wavefront 16. SECURITY...S L M P ix e l- c a m Tilted Flat Mirror L a s e r PV. ± 3.4 λ -Tilt by the flat mirror, ~7 waves ~ 14 fringes Interferogram 3D view (Various...Interferogram ( 3D view) x- profile y- profile (Various waveplates and telescopes not shown) SLM can compensate tilted wavefronts with an accuracy of

Climate Change Effects: Issues for International and US National Security

Science.gov (United States)

2009-07-01

Philip Meade, Mr. Michael Nash, Ms. Vanessa Pena, Mr. Ronald Rolph, Dr. Jocelyn Seng, Mr. Mark Tillman, Dr. Richard Van Atta, Mr. Ryan Wagner, Gen...DeRiggi, Dr. Tony Fainberg, Mr. Keith Green, Mr. Frederick Hartman, Mr. Edward Kenschaft, Dr. Gregory Larsen, Dr. Jamie Link, Mr. Frank Mahncke, Mr...Worst-case Scenario of Climate Change in the South-west Pacific, study by Edwards . Study   Appendix B:   Recommendations for DoD – Response to

Linearization of Nonautonomous Impulsive System with Nonuniform Exponential Dichotomy

Directory of Open Access Journals (Sweden)

Yongfei Gao

2014-01-01

Full Text Available This paper gives a version of Hartman-Grobman theorem for the impulsive differential equations. We assume that the linear impulsive system has a nonuniform exponential dichotomy. Under some suitable conditions, we proved that the nonlinear impulsive system is topologically conjugated to its linear system. Indeed, we do construct the topologically equivalent function (the transformation. Moreover, the method to prove the topological conjugacy is quite different from those in previous works (e.g., see Barreira and Valls, 2006.

Low Energy X-Ray Diagnostics - 1981.

Science.gov (United States)

1981-01-01

41MEAS) Opt. Comm., 9, 246, (1973); also Phys. Rev. A, ( MODELED ) .01 11, 989, (1975). 13. R. Thack, H. Mahr, C. L. Tang, and P. L. Hartman , Phys. Rev...Transmission Gratings: R. Tatchyn and I. Lindau 301 Analysis and Modeling Results Holographic X-Ray Gratings to be Produced at P.L. Csonka and R...orbit. The degree of polarization depends on the Calfonia ad CSR an8 eVstorage ring at Cornell electron energy, wavelength, and vertical viewing Univrsit

Cyber Security and Reliability in a Digital Cloud

Science.gov (United States)

2013-01-01

Runs the Mission  Mr. Bret Hartman  RSA  The Intelligent Security  Operations Center and  Advanced Persistent Threats  Mr. Chris C. Kemp  OpenStack  Cloud...Software  OpenStack  Cloud Software  Mr. Pravin Kothari  CipherCloud  Cloud Data Protection  Dr. John C. Mitchell  Stanford University  Innovation in

Falkner-Skan Flow of a Maxwell Fluid with Heat Transfer and Magnetic Field

Directory of Open Access Journals (Sweden)

M. Qasim

2013-01-01

Full Text Available This investigation deals with the Falkner-Skan flow of a Maxwell fluid in the presence of nonuniform applied magnetic fi…eld with heat transfer. Governing problems of flow and heat transfer are solved analytically by employing the homotopy analysis method (HAM. Effects of the involved parameters, namely, the Deborah number, Hartman number, and the Prandtl number, are examined carefully. A comparative study is made with the known numerical solution in a limiting sense and an excellent agreement is noted.

Recent Naval Postgraduate School Publications.

Science.gov (United States)

1984-06-01

U.S. Army Training & Doctrine Ccmmand, Fort Monroe, Va. Naval Postgraduate School, (NPS-55-80-023), June, 1980. 42 p. Hartman, J K Grcund movement ... movement Elmsford, N.Y., Pergamon, 1980. 300 p. Amos, J W Deception and the Middle East war IN D. C. Daniel and K. L. Herbig, eds.: Strategic military...Service, (NOAA), i6 p., (1980). * Moose, P B The qradient maqnetC- telluric method at the sea floor IEE Trans. Geoscience and Remote Sensing, vol. 19, no. 1

Sensitive seminested PCR method for the detection of Shigella in spiked environmental water samples

CSIR Research Space (South Africa)

Theron, J

2001-03-01

Full Text Available to shigellae and EIEC and implicated in virulent functions, is present in multiple copies on the invasion plasmid and the chromosome (Venkatesan et al., 1989, 1991; Hartman et al., 1990; Hale, 1991). The standard procedure for Shigella spp. detection is based... on isolation of Shigella by selective culture media followed by identi?cation by biochemical tests and agglutination assays (Frankel et al., 1989; June et al., 1993). This process may take 48?72 h or even longer to obtain results. Since shigellae are very...

Anelídeos poliquetos associados a um briozoário: III. Polynoidae Polychaetous annelids associated to a bryozoan: III. Polynoidae

Directory of Open Access Journals (Sweden)

Eloisa H Morgado

1981-06-01

Full Text Available Four species of Polynoidae, found in colonies of the bryozoan Schizoporella unicorns (Johnston, are here described. Among these Scalisetosus gracilis is a new species for science, and Halosdna glabra Hartman and Harmathöe macginitiei Pettibone, cited by the first time for Brazilian coast. Lepisdonotus caeruleus was the most abundant species of the family. Scalisetosus gracilis sp. nov. is characterized by the elytra with long and bifid papillae scattered on the surface as well as on external borders and distinct notosetae and neurosetae.

Proceedings of the Open Sessions of the Workshop on Imaging Trackers and Autonomous Acquisition Applications for Missile Guidance Held at Redstone Arsenal, Alabama on 19-20 November 1979

Science.gov (United States)

1979-11-01

L REF ERENCES 1. Savitzky, A. and Golay, M.%J.E; Anal Chemn 3b, 1964, p. 1627. 2. Steiner , J et al.; Anal Chem 44, 1972, p. 1906. 3. EDike, C. G...improve co).’Cii i x. ,agorithms to adjust to the effects of preprocessing operations. J. ACKNOWLEDGMENTS The authors wish to thank, Mr. W. L. Steiner ...63166 Hix, Rudolf G. General Dynamics/Pomona Div. Hartman, Richard P.O. Box 2507 U.S. Army Missile Command Pomona, California 91766 ATTN: DRSMI-RR

Heat transfer analysis for unsteady MHD flow past a non-isothermal stretching surface

International Nuclear Information System (INIS)

Mukhopadhyay, Swati

2011-01-01

Highlights: ► Unsteady boundary layer flow and heat transfer over a non-isothermal stretching sheet in a magnetic field are studied. ► Fluid velocity and temperature decrease for increasing unsteadiness parameter. ► Fluid velocity decreases but temperature increases with the increasing values of the Hartman number. ► The sheet temperature in respect of distance and time has analogous effects on the heat transfer. - Abstract: An analysis is made for the unsteady two-dimensional magneto-hydrodynamic flow of an incompressible viscous and electrically conducting fluid over a stretching surface having a variable and general form of surface temperature which removes the restrictions of the particular forms of prescribed surface temperature. Similarity solutions for the transformed governing equations are obtained. The transformed boundary layer equations are solved numerically for some values of the involved parameters, namely the unsteadiness parameter, magnetic parameter, the temperature exponent parameters. The features of the flow and heat transfer characteristics for different values of the governing parameters are analysed and discussed. It is found that the fluid velocity and temperature decrease for increasing unsteadiness parameter. Fluid velocity decreases with the increasing values of the Hartman number resulting an increase in the temperature field in steady as well in unsteady case. It is observed that the variation of the sheet temperature in respect of distance and time has analogous effects both on the free surface temperature and on the heat transfer rate (Nusselt number) at the sheet.

Book Review: Remodeling GT once again

Directory of Open Access Journals (Sweden)

Alvita Nathaniel

2014-06-01

Full Text Available Barry Gibson and Jan Hartman (2014: Rediscovering Grounded Theory London: Sage In their book entitled Rediscovering Grounded Theory, Barry Gibson and Jan Hartman (2014 aim to present grounded theory in a new way with the intention of “forward looking preservation” (p. 237. They claim that Rediscovery is an outcome of many conversations in a London pub over the last eight years. The authors tackle both method and methodology as they meticulously describe the context of The Discovery of Grounded Theory (Glaser & Strauss, 1967 and take an authoritative stand on many of the controversies surrounding remodeling of the method in recent years. Rediscovering also includes substantial how-to sections corresponding to chapters in Glaser’s Theoretical Sensitivity (1978. Rediscovery adds explanatory depth in its discussion of the context of grounded theory, but fails to keep many of its promises. Rediscovery is far reaching. Included in the first part are chapters entitled, What Kind of Theory is Grounded Theory, Constructivism in Grounded Theory, Disentangling Concepts and Categories in Grounded Theory, and Coding in Grounded Theory. These chapters describe the context of the method, discuss the controversies, and present Gibson and Hardman’s positions on contentious issues. The second part of the book consists of chapters that aim to help grounded theorists with procedures such as developing theoretical sensitivity, theoretical sampling, coding, memoing, and writing theory. To their credit, the authors continually acknowledge the originators of the method.

Tailoring hospital marketing efforts to physicians' needs.

Science.gov (United States)

Mackay, J M; Lamb, C W

1988-12-01

Marketing has become widely recognized as an important component of hospital management (Kotler and Clarke 1987; Ludke, Curry, and Saywell 1983). Physicians are becoming recognized as an important target market that warrants more marketing attention than it has received in the past (Super 1987; Wotruba, Haas, and Hartman 1982). Some experts predict that hospitals will begin focusing more marketing attention on physicians and less on consumers (Super 1986). Much of this attention is likely to take the form of practice management assistance, such as computer-based information system support or consulting services. The survey results reported here are illustrative only of how one hospital addressed the problem of physician need assessment. Other potential target markets include physicians who admit patients only to competitor hospitals and physicians who admit to multiple hospitals. The market might be segmented by individual versus group practice, area of specialization, or possibly even physician practice life cycle stage (Wotruba, Haas, and Hartman 1982). The questions included on the survey and the survey format are likely to be situation-specific. The key is the process, not the procedure. It is important for hospital marketers to recognize that practice management assistance needs will vary among markets (Jensen 1987). Therefore, hospitals must carefully identify their target physician market(s) and survey them about their specific needs before developing and implementing new physician marketing programs. Only then can they be reasonably confident that their marketing programs match their customers' needs.

Numerical investigation of fully-developed magneto-hydro-dynamic flows in ducts

International Nuclear Information System (INIS)

Dajeh, D. A.

1996-01-01

In this paper a numerical study is presented for fuly developed magnetic-hydrodynamic flows in ducts under a uniform transverse implied magnetic field. Afinite different scheme comprising of modified ADI 'Alternating Direction Implicit' method and a SOUR 'Sucessive-Over and under relaxation' method are used to solve the set of governing equations. Computations are carried out for a different shape of ducts over a wide range of Hartman number, up to five thousands, which is an important parameter in the nuclear fusion reactor design. (author).16 refs., 7 figs., 3 tabs

Quantum tunneling time of a Bose-Einstein condensate traversing through a laser-induced potential barrier

International Nuclear Information System (INIS)

Duan Zhenglu; Fan Bixuan; Yuan Chunhua; Zhang Weiping; Cheng Jing; Zhu Shiyao

2010-01-01

We theoretically study the effect of atomic nonlinearity on the tunneling time in the case of an atomic Bose-Einstein condensate (BEC) traversing the laser-induced potential barrier. The atomic nonlinearity is controlled to appear only in the region of the barrier by employing the Feshbach resonance technique to tune interatomic interaction in the tunneling process. Numerical simulation shows that the atomic nonlinear effect dramatically changes the tunneling behavior of the BEC matter wave packet and results in the violation of the Hartman effect and the occurrence of negative tunneling time.

Interpretation of recent positron-electron measurements between 20 and 800 MeV

International Nuclear Information System (INIS)

Pellerin, C.J.; Hartman, R.C.

1975-01-01

The recent positron and negatron spectra measured by Hartman and Pellerin (see pages 402-407) are discussed with regard to the problem of solar modulation. At energies above 180 MeV, the spherically symmetric Fokker-Planck equation with a diffusion coefficient proportional to particle rigidity provides reasonable fits to both the positron and total electron data. At energies below 180 MeV the data are consistent with a continuation of the same diffusion coefficient and local source of negatrons, or a change in the diffusion coefficient to a constant value. (orig.) [de

DAUR OPTIMAL TEGAKAN GMELINA PADA DUA PROYEK KARBON: MEMPERPANJANG DAUR DAN AFORESTASI

Directory of Open Access Journals (Sweden)

Yonky Indrajaya

2017-02-01

proyek karbon: memperpanjang daur dan aforestasi. Metode yang digunakan dalam penelitian ini adalah metode Faustmann yang dimodifikasi (yaitu Hartman yaitu maksimasi keuntungan dengan sumber pendapatan dari kayu dan jasa lingkungan penyerapan karbon. Hasil dari penelitian ini menunjukkan bahwa harga karbon akan memengaruhi daur optimal tegakan gmelina pada proyek karbon VCS memperpanjang daur tebang. Sementara itu, pada proyek aforestasi VCS, tingkat harga karbon tidak memengaruhi daur optimal Faustmann. Nilai NPV proyek aforestasi relatif  lebih tinggi dibandingkan nilai NPV proyek memperpanjang daur tebangan karena jumlah karbon yang dapat dikreditkan relatif  lebih tinggi pada proyek aforestasi.

X-ray active mirror coupled with a Hartmann wavefront sensor

International Nuclear Information System (INIS)

Idir, Mourad; Mercere, Pascal; Modi, Mohammed H.; Dovillaire, Guillaume; Levecq, Xavier; Bucourt, Samuel; Escolano, Lionel; Sauvageot, Paul

2010-01-01

This paper reports on the design and performances of a test prototype active X-ray mirror (AXM) which has been designed and manufactured in collaboration with the French Small and Medium Enterprise mechanical company ISP System for the national French storage ring SOLEIL. Coupled with this active X-ray mirror and also in collaboration with another French Small and Medium Enterprise (Imagine Optic) a lot of efforts have been done in order to design and fabricate a wavefront X-ray analyzer based on the Hartmann principle (Hartman wavefront sensor, HWS).

Protecting Mother Earth: Hartman Seeks to Instill His Passion in Science Students

Science.gov (United States)

Dea, Sarah

2010-01-01

Students at Fort Berthold Community College (FBCC) have spent their entire lives hearing about the environmental issues facing the Three Affiliated Tribes (Mandan, Hidatsa, and Arikara). Located on the high plains of northwestern North Dakota, the area contains rich coal and oil resources, the development of which can damage air and water quality.…

Salecker-Wigner-Peres clock and average tunneling times

International Nuclear Information System (INIS)

Lunardi, Jose T.; Manzoni, Luiz A.; Nystrom, Andrew T.

2011-01-01

The quantum clock of Salecker-Wigner-Peres is used, by performing a post-selection of the final state, to obtain average transmission and reflection times associated to the scattering of localized wave packets by static potentials in one dimension. The behavior of these average times is studied for a Gaussian wave packet, centered around a tunneling wave number, incident on a rectangular barrier and, in particular, on a double delta barrier potential. The regime of opaque barriers is investigated and the results show that the average transmission time does not saturate, showing no evidence of the Hartman effect (or its generalized version).

Vertical Windshear Below 5.5 Kilometers in the Vicinity of Berlin, Germany.

Science.gov (United States)

1986-08-01

cipitation amount forecasting using model output statistics. Mon. Wea. Rev., 113: 1837-1851. 7. Ohring, G., Neeman, B., and L. D. Duncan, 1981...Kelly 2 Eglin AFB, FL 32542 ADTC/XRCE (D. Dingus)I Eglin APR, FL 32542 AFATL/ LMT I Eglin AFM, FL 32542 Comma nd1er US Army OTF.A I ’qTTN: csr F-srs -I...RD-SS-SD I -RD-SS-AT I -RD-AS I -RD-AS-MM I -RD-AS I -RD-AS-SS I -RD-GC I -RD-RE, Dr. Hartman /Dr. Rennett/Ms. Romine 3 -RD-RE-AP, Dr. Essenwanger 15

A study on high speed wavefront control algorithm for an adaptive optics system

International Nuclear Information System (INIS)

Park, Seung Kyu; Baik, Sung Hoon; Kim, Cheol Jung; Seo, Young Seok

2000-01-01

We developed a high speed control algorithm and system for measuring and correcting the wavefront distortions based on Windows operating system. To get quickly the information of wavefront distortion from the Hartman spot image, we preprocessed the image to remove background noises and extracted the centroid position by finding the center of weights. We moved finely the centroid position with sub-pixel resolution repeatedly to get the wavefront information with more enhanced resolution. We designed a differential data communication driver and an isolated analog driver to have robust system control. As the experimental results, the measurement resolution of the wavefront was 0.05 pixels and correction speed was 5Hz

Transverse thermopherotic MHD Oldroyd-B fluid with Newtonian heating

Science.gov (United States)

Mehmood, R.; Rana, S.; Nadeem, S.

2018-03-01

Hydromagnetic transverse flow of an Oldroyd-B type fluid with suspension of nanoparticles and Newtonian heating effects is conferred in this article. Relaxation and Retardation time effects are taken into consideration. Using suitable transformations physical problem is converted into non-linear ordinary differential equations which are tackled numerically via Runge-Kutta Fehlberg integration scheme. Illustration of embedded constraints on flow characteristics are extracted through graphs. The physical response of velocity, temperature and concentration are investigated computationally. Momentum boundary layer thickness decreases but local heat and mass flux rises for Deborah number and Hartman number. The results provide interesting insights into certain applicable transport phenomena involving hydromagnetic rheological fluids.

Alfven wave absorption in dissipative plasma

International Nuclear Information System (INIS)

Gavrikov, M B; Taiurskii, A A

2017-01-01

We consider nonlinear absorption of Alfven waves due to dissipative effects in plasma and relaxation of temperatures of electrons and ions. This study is based on an exact solution of the equations of two-fluid electromagnetic hydrodynamics (EMHD) of plasma. It is shown that in order to study the decay of Alfven waves, it suffices to examine the behavior of their amplitudes whose evolution is described by a system of ordinary differential equations (ODEs) obtained in this paper. On finite time intervals, the system of equations on the amplitudes is studied numerically, while asymptotic integration (the Hartman-Grobman theorem) is used to examine its large-time behavior. (paper)

Holographic description of AdS2 black holes

International Nuclear Information System (INIS)

Castro, Alejandra; Larsen, Finn; Grumiller, Daniel; McNees, Robert

2008-01-01

We develop the holographic renormalization of AdS 2 gravity systematically. We find that a bulk Maxwell term necessitates a boundary mass term for the gauge field and verify that this unusual term is invariant under gauge transformations that preserve the boundary conditions. We determine the energy-momentum tensor and the central charge, recovering recent results by Hartman and Strominger. We show that our expressions are consistent with dimensional reduction of the AdS 3 energy-momentum tensor and the Brown-Henneaux central charge. As an application of our results we interpret the entropy of AdS 2 black holes as the ground state entropy of a dual CFT.

Hall effects on free convection hydromagnetic boundary layer flow of Rivlin-Ericksen fluid past a vertical plate

International Nuclear Information System (INIS)

Jha, P.K.

1986-01-01

An attempt has been made to study the problem of free convection hydromagnetic flow of an elastico-viscous fluid past a porous vertical plate in a rotating frame of reference taking ohmic and viscous dissipations into account in the presence of Hall current. The nature of velocity profile shows the existence of multiple boundary layers. Their 'thickness' is seen to decrease with increasing values of Ekman, Hartman and Prandtl numbers and Hall parameter. The graphical study reveals that the increasing values of Hall parameter and Ekman number (for a fixed large value of Hall parameter) exert opposite influence on the flow. (author). 11 refs., 2 tables

Mixed convection in a nanofluid filled-cavity with partial slip subjected to constant heat flux and inclined magnetic field

Energy Technology Data Exchange (ETDEWEB)

Ismael, Muneer A. [Mechanical Engineering Department, Engineering College, University of Basrah, Basrah (Iraq); Mansour, M.A. [Department of Mathematics, Assuit University, Faculty of Science, Assuit (Egypt); Chamkha, Ali J. [Mechanical Engineering Department, Prince Mohammad Bin Fahd University, Al-Khobar 31952 (Saudi Arabia); Prince Sultan Endowment for Energy and Environment, Prince Mohammad Bin Fahd University, Al-Khobar 31952 (Saudi Arabia); Rashad, A.M., E-mail: am_rashad@yahoo.com [Department of Mathematics, Aswan University, Faculty of Science, Aswan 81528 (Egypt)

2016-10-15

Mixed convection in a lid-driven square cavity filled with Cu-water nanofluid and subjected to inclined magnetic field is investigated in this paper. Partial slip effect is considered along the lid driven horizontal walls. A constant heat flux source on the left wall is considered, meanwhile the right vertical wall is cooled isothermally. The remainder cavity walls are thermally insulted. A control finite volume method is used as a numerical appliance of the governing equations. Six pertinent parameters were studied these; the orientation of the magnetic field (Φ=0–360°), Richardson number (Ri=0.001–1000), Hartman number (Ha=0–100), the size and position of the heat source (B=0.2–0.8, D=0.3–0.7, respectively), nanoparticles volume fraction (ϕ=0.0–0.1), and the lid-direction of the horizontal walls (λ=±1) where the positive sign means lid-driven to the right while the negative sign means lid-driven to the left. The results show that the orientation and the strength of the magnetic field can play a significant role in controlling the convection under the effect of partial slip. It is also found that the natural convection decreases with increasing the length of the heat source for all ranges of the studied parameters, while it is do so due to the vertical distance up to Hartman number of 50, beyond this value the natural convection decreases with lifting the heat source narrower to the top wall. - Highlights: • Partial slip along moving walls of MHD cavity filled with nanofluid is considered. • The suppression exerted by the magnetic field decreases with its orientation. • Nusselt number is enhanced slightly with nanoparticles at shortest heat source. • Nusselt number is enhanced with nanoparticles at stronger magnetic field.

Mixed convection in a nanofluid filled-cavity with partial slip subjected to constant heat flux and inclined magnetic field

International Nuclear Information System (INIS)

Ismael, Muneer A.; Mansour, M.A.; Chamkha, Ali J.; Rashad, A.M.

2016-01-01

Mixed convection in a lid-driven square cavity filled with Cu-water nanofluid and subjected to inclined magnetic field is investigated in this paper. Partial slip effect is considered along the lid driven horizontal walls. A constant heat flux source on the left wall is considered, meanwhile the right vertical wall is cooled isothermally. The remainder cavity walls are thermally insulted. A control finite volume method is used as a numerical appliance of the governing equations. Six pertinent parameters were studied these; the orientation of the magnetic field (Φ=0–360°), Richardson number (Ri=0.001–1000), Hartman number (Ha=0–100), the size and position of the heat source (B=0.2–0.8, D=0.3–0.7, respectively), nanoparticles volume fraction (ϕ=0.0–0.1), and the lid-direction of the horizontal walls (λ=±1) where the positive sign means lid-driven to the right while the negative sign means lid-driven to the left. The results show that the orientation and the strength of the magnetic field can play a significant role in controlling the convection under the effect of partial slip. It is also found that the natural convection decreases with increasing the length of the heat source for all ranges of the studied parameters, while it is do so due to the vertical distance up to Hartman number of 50, beyond this value the natural convection decreases with lifting the heat source narrower to the top wall. - Highlights: • Partial slip along moving walls of MHD cavity filled with nanofluid is considered. • The suppression exerted by the magnetic field decreases with its orientation. • Nusselt number is enhanced slightly with nanoparticles at shortest heat source. • Nusselt number is enhanced with nanoparticles at stronger magnetic field.

Numerical Simulation for Magneto Nanofluid Flow Through a Porous Space with Melting Heat Transfer

Science.gov (United States)

Hayat, T.; Shah, Faisal; Alsaedi, A.; Waqas, M.

2018-02-01

Melting heat transfer and non-Darcy porous medium effects in MHD stagnation point flow toward a stretching surface of variable thickness are addressed. Brownian motion and thermophoresis in nanofluid modeling are retained. Zero mass flux condition for concentration at surface is imposed. The problem of ordinary differential system are analyzed numerically through shooting technique. Graphically results of various physical variables on the velocity, temperature and concentration are studied. Skin friction coefficient local Nusselt number and Sherwood number are also addressed through tabulated values. The results described here illustrate that the velocity field is higher via larger melting parameter. However reverse situation is examined for Hartman number. Moreover the influence of thermophoresis parameter on temperature and concentration is noted similar.

Holographic geometry of cMERA for quantum quenches and finite temperature

International Nuclear Information System (INIS)

Mollabashi, Ali; Naozaki, Masahiro; Ryu, Shinsei; Takayanagi, Tadashi

2014-01-01

We study the time evolution of cMERA (continuous MERA) under quantum quenches in free field theories. We calculate the corresponding holographic metric using the proposal in http://arxiv.org/abs/1208.3469 and confirm that it qualitatively agrees with its gravity dual given by a half of the AdS black hole spacetime, argued by Hartman and Maldacena in http://arxiv.org/abs/1303.1080. By doubling the cMERA for the quantum quench, we give an explicit construction of finite temperature cMERA. We also study cMERA in the presence of chemical potential and show that there is an enhancement of metric in the infrared region corresponding to the Fermi energy

Groundwater Monitoring Plan for the 1301-N, 1324-N/NA, and 1325-N RCRA Facilities

International Nuclear Information System (INIS)

Hartman, Mary J.

2001-01-01

The 1301-N and 1325-N Liquid Waste Disposal Facilities, the 1324-N Surface Impoundment, and the 1324-NA Percolation Pond, located in the 100 N Area of the Hanford Site, are regulated under the Resource Conservation and Recovery Act of 1976 (RCRA). The closure plans for these facilities stipulate that groundwater is monitored according to the 100-N Pilot Project: Proposed Consolidated Groundwater Monitoring Program (BHI-00725). This document supplements the consolidated plan by providing information on sampling and analysis protocols, quality assurance, data management, and a conceptual model for the RCRA sites. Monitoring well networks, constituents, and sampling frequency remain the same as in the consolidated plan or the previous groundwater monitoring plan (Hartman 1996)

Effects of mass transfer on MHD flow of casson fluid with chemical reaction and suction

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S. A. Shehzad

2013-03-01

Full Text Available Effect of mass transfer in the magnetohydrodynamic flow of a Casson fluid over a porous stretching sheet is addressed in the presence of a chemical reaction. A series solution for the resulting nonlinear flow is computed. The skin friction coefficient and local Sherwood number are analyzed through numerical values for various parameters of interest. The velocity and concentration fields are illustrated for several pertinent flow parameters. We observed that the Casson parameter and Hartman number have similar effects on the velocity in a qualitative sense. We further analyzed that the concentration profile decreases rapidly in comparison to the fluid velocity when we increased the values of the suction parameter.

Numerical Simulation for Magneto Nanofluid Flow Through a Porous Space with Melting Heat Transfer

Science.gov (United States)

Hayat, T.; Shah, Faisal; Alsaedi, A.; Waqas, M.

2018-05-01

Melting heat transfer and non-Darcy porous medium effects in MHD stagnation point flow toward a stretching surface of variable thickness are addressed. Brownian motion and thermophoresis in nanofluid modeling are retained. Zero mass flux condition for concentration at surface is imposed. The problem of ordinary differential system are analyzed numerically through shooting technique. Graphically results of various physical variables on the velocity, temperature and concentration are studied. Skin friction coefficient local Nusselt number and Sherwood number are also addressed through tabulated values. The results described here illustrate that the velocity field is higher via larger melting parameter. However reverse situation is examined for Hartman number. Moreover the influence of thermophoresis parameter on temperature and concentration is noted similar.

WAVEFRONT TESTER: Un nuevo laboratorio virtual para el estudio de los sensores frente de onda.

Directory of Open Access Journals (Sweden)

Vicente Ferrando Martín

2016-01-01

Full Text Available Se presenta un laboratorio virtual desarrollado en MATLAB GUI (Graphical User Interface para ser utilizado en la asignatura de "Tecnología de Sensores Optoelectrónicos" que se imparte en  "Escuela Técnica Superior de Ingeniería del Diseño" de la Universitat Politècnica de València. El objetivo de este laboratorio es servir de herramienta informática para el estudio de un sensor Shack Hartman y los parámetros que determinan el rango dinámico del mismo en la medida de las aberraciones. Se presentan distintos ejemplos realizados con diferentes aberraciones (desenfoque, astigmatismo, coma y para diferentes configuraciones del sensor.

Numerical study for peristalsis of Carreau-Yasuda nanomaterial with convective and zero mass flux condition

Science.gov (United States)

Hayat, T.; Ahmed, Bilal; Alsaedi, A.; Abbasi, F. M.

2018-03-01

The present communication investigates flow of Carreau-Yasuda nanofluid in presence of mixed convection and Hall current. Effects of viscous dissipation, Ohmic heating and convective conditions are addressed. In addition zero nanoparticle mass flux condition is imposed. Wave frame analysis is carried out. Coupled differential systems after long wavelength and low Reynolds number are numerically solved. Effects of different parameters on velocity, temperature and concentration are studied. Heat and mass transfer rates are analyzed through tabular values. It is observed that concentration for thermophoresis and Brownian motion parameters has opposite effect. Further heat and mass transfer rates at the upper wall enhances significantly when Hartman number increases and reverse situation is noticed for Hall parameter.

Well drilling summary report for well 199-N-106A

International Nuclear Information System (INIS)

Walker, L.D.

1996-02-01

Past liquid waste disposal practices within the 100-N Area have resulted in the contamination of the underlying sediments and groundwater. The release of large volumes of liquid effluent to the 1301-N and 1325-N Liquid Waste Disposal Facilities caused the transport of 90 Sr and other contaminants to the groundwater. Further discussion of 100-N Area hydrogeology is provided in Hartman and Lindsey (1993). A pump-and-treat system combined with a vertical barrier is the preferred alternative for the N Springs Expedited Response Action. This document is a compilation of the data collected during the drilling of well 199-N-106A, an extraction well for the 100-N Pump-and-Treat Project

Unified time analysis of photon and particle tunnelling

International Nuclear Information System (INIS)

Olkhovsky, Vladislav S.; Recami, Erasmo; Jakiel, Jacek

2001-07-01

A unified approach to the time analysis of tunnelling of nonrelativistic particles is presented, in which Time is regarded as a quantum-mechanical observable, canonically conjugated to Energy. The validity of the Hartman effect (independence of the Tunnelling Time of the opaque barrier width, with superluminal group velocities as a consequence) is verified for all the known expressions of the mean tunnelling time. Moreover, the analogy between particle and photon tunnelling is suitably exploited. On the basic of such an analogy, an explanation of some recent microwave and optics experimental results on tunnelling time is proposed. Attention is devoted to some aspects of the causality problem for particle and photon tunnelling. (author)

Photometric study of an eclipsing binary in the field of M37

International Nuclear Information System (INIS)

Priya Devarapalli Shanti; Sriram Kandulapati; Rao Pasagada Vivekananda

2014-01-01

CCD photometric observations with B and V passbands were performed on the contact binary V3 in the field of open cluster M37. The solutions were obtained for data from both B and V passbands along with R passband given by Hartman et al. using the Wilson-Devinney code. The positive O'Connell effect was observed in all the three passbands and its associated cool spot parameters were derived. The results indicate that the spot parameters have not shown any significant variability during the last four years. The spot radius was found to be 40° and located close to the equator of the secondary component. The absolute parameters of the system were derived using the empirical relations given by Gazeas et al. (research papers)

Dual Solutions for Nonlinear Flow Using Lie Group Analysis.

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Muhammad Awais

Full Text Available `The aim of this analysis is to investigate the existence of the dual solutions for magnetohydrodynamic (MHD flow of an upper-convected Maxwell (UCM fluid over a porous shrinking wall. We have employed the Lie group analysis for the simplification of the nonlinear differential system and computed the absolute invariants explicitly. An efficient numerical technique namely the shooting method has been employed for the constructions of solutions. Dual solutions are computed for velocity profile of an upper-convected Maxwell (UCM fluid flow. Plots reflecting the impact of dual solutions for the variations of Deborah number, Hartman number, wall mass transfer are presented and analyzed. Streamlines are also plotted for the wall mass transfer effects when suction and blowing situations are considered.

A numerical study of magnetohydrodynamics flow in Casson nanofluid combined with Joule heating and slip boundary conditions

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A. Kamran

Full Text Available A numerical study of Casson nanofluid past horizontal stretching surface with magnetic effect and Joule heating are presented. Slip and thermal convective boundary conditions are considered in the study. A numerical technique of Keller box is applied to the nonlinear ODEs which are obtained by applying the similarity transformation to the nonlinear partial differential equations. The magnetic field and Joule heating effects are observed graphically. Also the strength of convective heat exchange (Nusselt number and the strength of mass exchange (Sherwood number are analyzed. It is noted that Nusselt number declines whereas Sherwood number rises by increasing Eckert number. The impact of increasing Hartman number resulted in the decrease of both Sherwood and Nusselt number. Keywords: Casson nanofluid, Magnetohydrodynamic, Joule heating, Keller box method

Subluminal and superluminal pulse propagation in inhomogeneous media of nonspherical particles

International Nuclear Information System (INIS)

Ma Yu; Gao Lei

2006-01-01

We study the pulse propagation through a metal/dielectric composites of nonspherical particles enclosed by two gold mirrors. To account for the shape effect, we first adopt Maxwell-Garnett type approximation to obtain the effective dielectric function of composites. Based on the group index, phase time and pulse shape calculations, we find that the particles' shape (characterized by the depolarization factor) plays an important role in determining the subluminal and superluminal pulse propagations through the system. When the inclusions' shape is not spherical, it is possible to observe significant superluminal behavior of the pulse propagation, although the volume fraction is the same. The shape-dependent critical volume fraction is predicted, above which superluminal propagation appears. Furthermore, the Hartman effect in such a system is also investigated

Phonon tunneling through a double barrier system

International Nuclear Information System (INIS)

Villegas, Diosdado; León-Pérez, Fernando de; Pérez-Álvarez, R.; Arriaga, J.

2015-01-01

The tunneling of optical and acoustic phonons at normal incidence on a double-barrier is studied in this paper. Transmission coefficients and resonance conditions are derived theoretically under the assumption that the long-wavelength approximation is valid. It is shown that the behavior of the transmission coefficients for the symmetric double barrier has a Lorentzian form close to resonant frequencies and that Breit–Wigner's formula have a general validity in one-dimensional phonon tunneling. Authors also study the so-called generalized Hartman effect in the tunneling of long-wavelength phonons and show that this effect is a numerical artifact resulting from taking the opaque limit before exploring the variation with a finite barrier width. This study could be useful for the design of acoustic devices

Namalycastis occulta n. sp. and a new record of N. borealis (Polychaeta: Nereididae: Namanereidinae) from the Northwestern Caribbean Sea.

Science.gov (United States)

Conde-Vela, Víctor Manuel

2013-01-01

The nereidid polychaete genus Namalycastis Hartman, 1959 has been recorded almost exclusively in non-marine environments. This genus includes species having four pairs of tentacular cirri, and its species mainly differ by the relative size of dorsal cirri in posterior chaetigers. Namalycastis occulta n. sp. is described based upon non-mature and mature specimens collected in the intertidal from Chetumal Bay, Quintana Roo, Mexico. Its distinctive features are the lack of notopodial spinigers, eyes, and teeth in the mandibles. Namalycastis borealis Glasby was found in Tamalcab Island, Chetumal Bay and it is the first record for Mexico. Analyses of the intraspecific variability, a key to the known species in the Grand Caribbean region, and commentaries about some taxonomic topics are also included.

Redescriptions and reestablishments of some species belonging to the genus Prionospio (Polychaeta, Spionidae) and descriptions of three new species

Science.gov (United States)

Delgado-Blas, V. H.

2014-03-01

Available type material of Prionospio heterobranchia Moore, 1907, P. ( Prionospio) texana Hartman, 1951, P. spongicola Wesenberg-Lund, 1958 and P. ( P.) newportensis Reish, 1959, as well as newly collected material from the Southern Gulf of Mexico and Chetumal Bay in the Caribbean Sea, was examined. Several important differences were found between P. heterobranchia, P. ( Prionospio) texana, P. spongicola and P. ( P.) newportensis, and as a result, these three species are removed from synonymy with P. heterobranchia Moore, 1907, and redescribed and reinstated as valid species. In addition, three new species were identified and described: P. caribensis sp. nov., P. rosariae sp. nov. and P. jamaicensis sp. nov. A key to all species of Prionospio with five pairs of branchiae is provided.

Phonon tunneling through a double barrier system

Energy Technology Data Exchange (ETDEWEB)

Villegas, Diosdado [Departamento de Física, Universidad Central “Marta Abreu” de Las Villas, CP 54830, Santa Clara, Villa Clara (Cuba); Instituto de Física, Universidad Autónoma de Puebla, 18 Sur y San Claudio, Edif. 110A, Ciudad Universitaria, 72570 Puebla (Mexico); León-Pérez, Fernando de [Centro Universitario de la Defensa de Zaragoza, Ctra. de Huesca s/n, E-50090 Zaragoza (Spain); Pérez-Álvarez, R. [Universidad Autónoma del Estado de Morelos, Av. Universidad 1001, CP 62209 Cuernavaca (Mexico); Arriaga, J., E-mail: arriaga@ifuap.buap.mx [Instituto de Física, Universidad Autónoma de Puebla, 18 Sur y San Claudio, Edif. 110A, Ciudad Universitaria, 72570 Puebla (Mexico)

2015-04-15

The tunneling of optical and acoustic phonons at normal incidence on a double-barrier is studied in this paper. Transmission coefficients and resonance conditions are derived theoretically under the assumption that the long-wavelength approximation is valid. It is shown that the behavior of the transmission coefficients for the symmetric double barrier has a Lorentzian form close to resonant frequencies and that Breit–Wigner's formula have a general validity in one-dimensional phonon tunneling. Authors also study the so-called generalized Hartman effect in the tunneling of long-wavelength phonons and show that this effect is a numerical artifact resulting from taking the opaque limit before exploring the variation with a finite barrier width. This study could be useful for the design of acoustic devices.

Compact torus compression of microwaves

International Nuclear Information System (INIS)

Hewett, D.W.; Langdon, A.B.

1985-01-01

The possibility that a compact torus (CT) might be accelerated to large velocities has been suggested by Hartman and Hammer. If this is feasible one application of these moving CTs might be to compress microwaves. The proposed mechanism is that a coaxial vacuum region in front of a CT is prefilled with a number of normal electromagnetic modes on which the CT impinges. A crucial assumption of this proposal is that the CT excludes the microwaves and therefore compresses them. Should the microwaves penetrate the CT, compression efficiency is diminished and significant CT heating results. MFE applications in the same parameters regime have found electromagnetic radiation capable of penetrating, heating, and driving currents. We report here a cursory investigation of rf penetration using a 1-D version of a direct implicit PIC code

Relevamiento de HI en el Hemisferio Austral

Science.gov (United States)

Arnal, E. M.; Bajaja, E.; Morras, R.; Pöppel, W. G. L.

Un nuevo relevamiento de HI de todo el Hemisferio Austral, comprendido entre -90o de ~50000 posiciones en el cielo serán observadas, espaciadas en una grilla (lxb) de (0.5o x 0.5o). El intervalo de velocidades cubierto en este relevamiento abarca el rango -450 km/s a +450 km/s en el sistema LSR. Esta base de datos será corregida por efectos de ``stray radiation''. Al presente se ha observado ~70% del total del relevamiento. El mismo es complementario de uno similar realizado en el Hemisferio Norte por Hartman y Burton (1996), con cubrimiento espacial, sensibilidad, resoluciones espaciales y en velocidad, similares a los del IAR. El objetivo final de ambos relevamientos es disponer de una base de datos uniforme en todo el cielo.

Numerical analysis for Darcy-Forchheimer flow in presence of homogeneous-heterogeneous reactions

Directory of Open Access Journals (Sweden)

Muhammad Ijaz Khan

Full Text Available A mathematical study is presented to investigate the influences of homogeneous and heterogeneous reactions in local similar flow caused by stretching sheet with a non-linear velocity and variable thickness. Porous medium effects are characterized by using Darcy-Forchheimer porous-media. A simple isothermal model of homogeneous-heterogeneous reactions is used. The multiphysical boundary value problem is dictated by ten thermophysical parameters: ratio of mass diffusion coefficients, Prandtl number, local inertia coefficient parameter, inverse Darcy number, shape parameter, surface thickness parameter, Hartman number, Homogeneous heat reaction, strength of homogeneous-heterogeneous reactions and Schmidt number. Resulting systems are computed by Runge-Kutta-Fehlberg method. Different shapes of velocity are noticed for n > 1 and n < 1. Keywords: Homogeneous-heterogeneous reactions, Non Darcy porous medium, Variable sheet thickness, Homogeneous heat reaction with stoichiometric coefficient, Runge-Kutta-Fehlberg method

Hydromagnetic nonlinear thermally radiative nanoliquid flow with Newtonian heat and mass conditions

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Muhammad Ijaz Khan

Full Text Available This paper communicates the analysis of MHD three-dimensional flow of Jeffrey nanoliquid over a stretchable surface. Flow due to a bidirectional surface is considered. Heat and mass transfer subject to volume fraction of nanoparticles, heat generation and nonlinear solar radiation are examined. Newtonian heat and mass transportation conditions are employed at surface. Concept of boundary layer is utilized to developed the mathematical problem. The boundary value problem is dictated by ten physical parameters: Deborah number, Hartman number, ratio of stretching rates, thermophoretic parameter, Brownian motion parameter, Prandtl number, temperature ratio parameter, conjugate heat and mass parameters and Lewis number. Convergent solutions are obtained using homotopic procedure. Convergence zone for obtained results is explicitly identified. The obtained solutions are interpreted physically. Keywords: Hydromagnetic flow, Viscoelastic nanofluid, Thermophoretic and Brownian moment, Nonlinear thermal radiation, Heat generation

Scrutiny of underdeveloped nanofluid MHD flow and heat conduction in a channel with porous walls

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M. Fakour

2014-11-01

Full Text Available In this paper, laminar fluid flow and heat transfer in channel with permeable walls in the presence of a transverse magnetic field is investigated. Least square method (LSM for computing approximate solutions of nonlinear differential equations governing the problem. We have tried to show reliability and performance of the present method compared with the numerical method (Runge–Kutta fourth-rate to solve this problem. The influence of the four dimensionless numbers: the Hartmann number, Reynolds number, Prandtl number and Eckert number on non-dimensional velocity and temperature profiles are considered. The results show analytical present method is very close to numerically method. In general, increasing the Reynolds and Hartman number is reduces the nanofluid flow velocity in the channel and the maximum amount of temperature increase and increasing the Prandtl and Eckert number will increase the maximum amount of theta.

Study of heat transfer and flow of nanofluid in permeable channel in the presence of magnetic field

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M. Fakour

2015-03-01

Full Text Available In this paper, laminar fluid flow and heat transfer in channel with permeable walls in the presence of a transverse magnetic field is investigated. Least square method (LSM for computing approximate solutions of nonlinear differential equations governing the problem. We have tried to show reliability and performance of the present method compared with the numerical method (Runge-Kutta fourth-rate to solve this problem. The influence of the four dimensionless numbers: the Hartmann number, Reynolds number, Prandtl number and Eckert number on non-dimensional velocity and temperature profiles are considered. The results show analytical present method is very close to numerically method. In general, increasing the Reynolds and Hartman number is reduces the nanofluid flow velocity in the channel and the maximum amount of temperature increase and increasing the Prandtl and Eckert number will increase the maximum amount of theta.

Gas exchange and growth responses to nutrient enrichment in invasive Glyceria maxima and native New Zealand Carex species

DEFF Research Database (Denmark)

Sorrell, Brian Keith; Brix, Hans; Fitridge, Isla

2012-01-01

We compared photosynthetic gas exchange, the photosynthesis-leaf nitrogen (N) relationship, and growth response to nutrient enrichment in the invasive wetland grass Glyceria maxima (Hartman) Holmburg with two native New Zealand Carex sedges (C. virgata Boott and C. secta Boott), to explore...... the ecophysiological traits contributing to invasive behaviour. The photosynthesis-nitrogen relationship was uniform across all three species, and the maximum light-saturated rate of photosynthesis expressed on a leaf area basis (Amaxa) did not differ significantly between species. However, specific leaf area (SLA...... the sedges, but correlations between leaf N, gas exchange parameters (Amaxa, Amaxm, Rd and gs) and RGR were all highly significant in G. maxima, whereas they were weak or absent in the sedges. Allocation of biomass (root:shoot ratio, leaf mass ratio, root mass ratio), plant N and P content, and allocation...

A frame work for heat generation/absorption and modified homogeneous–heterogeneous reaction in flow based on non-Darcy–Forchheimer medium

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Tasawar Hayat

2018-04-01

Full Text Available The present work aims to report the consequences of Darcy–Forchheimer medium in flow of Cross fluid model toward a stretched surface. Flow in porous space is categorized by Darcy–Forchheimer medium. Further heat transfer characteristics are examined via thermal radiation and heat generation/absorption. Transformation procedure is used. The arising system of nonlinear ordinary differential equations is solved numerically by means of shooting method. The effects of different flow variables on velocity, temperature, concentration, skin friction, and heat transfer rate are discussed. The obtained outcomes show that velocity was enhanced with the increase in the Weissenberg number but decays with increase in the porosity parameter and Hartman number. Temperature field is boosted by thermal radiation and heat generation; however, it decays with the increase in the Prandtl number. Keywords: Cross Fluid, Heat Generation/Absorption, Homogeneous–Heterogeneous Reactions, Non-Darcy–Forchheimer Medium, Thermal Radiation

On Cattaneo–Christov heat flux in MHD flow of Oldroyd-B fluid with homogeneous–heterogeneous reactions

International Nuclear Information System (INIS)

Hayat, Tasawar; Imtiaz, Maria; Alsaedi, Ahmed; Almezal, Saleh

2016-01-01

This paper investigates the steady two-dimensional magnetohydrodynamic (MHD) flow of an Oldroyd-B fluid over a stretching surface with homogeneous–heterogeneous reactions. Characteristics of relaxation time for heat flux are captured by employing new heat flux model proposed by Christov. A system of ordinary differential equations is obtained by using suitable transformations. Convergent series solutions are derived. Impacts of various pertinent parameters on the velocity, temperature and concentration are discussed. Analysis of the obtained results shows that fluid relaxation and retardation time constants have reverse behavior on the velocity and concentration fields. Also temperature distribution decreases for larger values of thermal relaxation time. - Highlights: • Cattaneo–Christov heat flux model is used to study the MHD flow of an Oldroyd-B fluid. • Velocity is decreasing function of Hartman number. • Increasing values of the strengths of homogeneous and heterogeneous reaction parameters decrease the wall concentration.

The flexibility of SIMPSON and SIMMOL for numerical simulations in solid-and liquid-state NMR spectroscopy

International Nuclear Information System (INIS)

Vosegaard, T.; Malmendal, A.; Nielsen, N.C.

2002-01-01

Addressing the need for numerical simulations in the design and interpretation of advanced solid- and liquid-state NMR experiments, we present a number of novel features for numerical simulations based on the SIMPSON and SIMMOL open source software packages. Major attention is devoted to the flexibility of these Tcl-interfaced programs for numerical simulation of NMR experiments being complicated by demands for efficient powder averaging, large spin systems, and multiple-pulse rf irradiation. These features are exemplified by fast simulation of second-order quadrupolar powder patterns using crystallite interpolation, analysis of rotary resonance triple-quantum excitation for quadrupolar nuclei, iterative fitting of MQ-MAS spectra by combination of SIMIPSON and MINUIT, simulation of multiple-dimensional PISEMA-type correlation experiments for macroscopically oriented membrane proteins, simulation of Hartman-Hahn polarization transfers in liquid-state NMR, and visualization of the spin evolution under complex composite broad-band excitation pulses. (author)

Time Dependent MHD Nano-Second Grade Fluid Flow Induced by Permeable Vertical Sheet with Mixed Convection and Thermal Radiation.

Directory of Open Access Journals (Sweden)

Muhammad Ramzan

Full Text Available The aim of present paper is to study the series solution of time dependent MHD second grade incompressible nanofluid towards a stretching sheet. The effects of mixed convection and thermal radiation are also taken into account. Because of nanofluid model, effects Brownian motion and thermophoresis are encountered. The resulting nonlinear momentum, heat and concentration equations are simplified using appropriate transformations. Series solutions have been obtained for velocity, temperature and nanoparticle fraction profiles using Homotopy Analysis Method (HAM. Convergence of the acquired solution is discussed critically. Behavior of velocity, temperature and concentration profiles on the prominent parameters is depicted and argued graphically. It is observed that temperature and concentration profiles show similar behavior for thermophoresis parameter Νt but opposite tendency is noted in case of Brownian motion parameter Νb. It is further analyzed that suction parameter S and Hartman number Μ depict decreasing behavior on velocity profile.

Operator-normalized quantum arrival times in the presence of interactions

International Nuclear Information System (INIS)

Hegerfeldt, G.C.; Seidel, D.; Muga, J.G.; Navarro, B.

2004-01-01

We model ideal arrival-time measurements for free quantum particles and for particles subject to an external interaction by means of a narrow and weak absorbing potential. This approach is related to the operational approach of measuring the first photon emitted from a two-level atom illuminated by a laser. By operator normalizing the resulting time-of-arrival distribution, a distribution is obtained which for freely moving particles not only recovers the axiomatically derived distribution of Kijowski for states with purely positive momenta but is also applicable to general momentum components. For particles interacting with a square barrier the mean arrival time and corresponding 'tunneling time' obtained at the transmission side of the barrier become independent of the barrier width (Hartman effect) for arbitrarily wide barriers, i.e., without the transition to the ultraopaque, classical-like regime dominated by wave packet components above the barrier

Gestão pessoal da carreira no Ensino Superior

Directory of Open Access Journals (Sweden)

Maria Céu Taveira

2008-01-01

Full Text Available This article presents five single case-studies, concerning the implementation of a psychological intervention program, designed to support granted doctoral students to plan their next career goals and to deal with transition to the labor-market issues. We present and discuss the results of the assessment of the counseling process through the use of the Client Reaction System (CRS (HILL; SPIEGEL; TICHENOR, 1988; GAS, adapt. by TAVEIRA, 2003, and also of the impact of the intervention in the career exploration process and in the definition of valued career goals by the participants, as assessed by the Career Exploration Survey (CES (STUMPF; COLARELLI; HARTMAN, 1983; EEV, adapt. by TAVEIRA, 1997 and by the Adult Career Concerns Inventory (ACCI (SUPER; THOMPSON; LINDEMAN, 1985; IPC, adapt. by DUARTE, 1997, respectively. Main implications of the study results for career counseling research and practice are discussed.

Outcome of homogeneous and heterogeneous reactions in Darcy-Forchheimer flow with nonlinear thermal radiation and convective condition

Science.gov (United States)

Hayat, T.; Shah, Faisal; Alsaedi, A.; Hussain, Zakir

The present analysis aims to report the consequences of nonlinear radiation, convective condition and heterogeneous-homogeneous reactions in Darcy-Forchheimer flow over a non-linear stretching sheet with variable thickness. Non-uniform magnetic field and nonuniform heat generation/absorption are accounted. The governing boundary layer partial differential equations are converted into a system of nonlinear ordinary differential equations. The computations are organized and the effects of physical variables such as thickness parameter, power index, Hartman number, inertia and porous parameters, radiation parameter, Biot number, Prandtl number, ratio parameter, heat generation parameter and homogeneous-heterogeneous reaction parameter are investigated. The variations of skin friction coefficient and Nusselt number for different interesting variables are plotted and discussed. It is noticed that Biot number and heat generation variable lead to enhance the temperature distribution. The solutal boundary layer thickness decreases for larger homogeneous variable while reverse trend is seen for heterogeneous reaction.

Environmental assessment for relocation of NREL research experiments

International Nuclear Information System (INIS)

1992-06-01

In compliance with the National Environmental Policy Act (NEPA), the Department of Energy (DOE) has prepared this environmental assessment (DOE/EA-0619) to evaluate the environmental consequences associated with the conduct of ongoing research activities of its National Renewable Energy Laboratory proposed to be relocated to leased commercial laboratory and warehouse space at 6800 Joyce Sum, in Arvada, Colorado. NREL is currently leasing space in Golden, Colorado, for conduct of the research actions discussed in the EA. The research project proposed for relocation is the Amorphous silicon Deposition Laboratory (ASDL). Additionally, it may be financially desirable to relocate the Scanning Hartman Optical Tester (SHOT) and the Whole Building Test Facility at a later date, therefore, the consequences of their operation at the proposed facility is evaluated in the EA to support such future decisions. The new location can also provide additional warehouse space required by NREL

Redescriptions of Nereis oligohalina (Rioja, 1946) and N. garwoodi González-Escalante & Salazar-Vallejo, 2003 and description of N. confusa sp. n. (Annelida, Nereididae).

Science.gov (United States)

Conde-Vela, Víctor M; Salazar-Vallejo, Sergio I

2015-01-01

Type material of several polychaete species described by Enrique Rioja from Mexican coasts are lost, and the current status of some species is doubtful. Nereis oligohalina (Rioja, 1946) was described from the Gulf of Mexico, but it has been considered a junior synonym of Nereis occidentalis Hartman, 1945, or regarded as a distinct species with an amphiamerican distribution. On the other hand, Nereis garwoodi González-Escalante & Salazar-Vallejo, 2003, described from Chetumal Bay, Caribbean coasts, could be confused with Nereis oligohalina. In order to clarify these uncertainties, Nereis oligohalina is redescribed based on specimens from the Mexican Gulf of Mexico, including a proposed neotype; further, Nereis garwoodi is redescribed including the selection of lectotype and paralectotypes, and Nereis confusa sp. n. is described with material from the Gulf of California. A key for the identification of similar species and some comments about speciation in nereidid polychaetes are also included.

Children as digital rights agents

DEFF Research Database (Denmark)

Stald, Gitte Bang

2016-01-01

This paper looks at children’s involvement and contribution to internet safety policy. In many respects, the research perspective on children and young people has also seen a shift towards the child as agent, as citizen (Livingstone 2002, 2009; Dahlgren 2007). With increasing attention given...... to children’s communication rights there is an acknowledgement that children’s voices should be heard in all matters that affect them (Hamelink 2008). We still, however, primarily discuss how adults could and should take responsibility in guarding children and young people from risk and harm, and what...... the role of the “adult world” is. We need to focus more on the active role that children and adolescents play, according to age, skills and various capacities, in identifying, reflecting upon and acting according to opportunities and challenges in relation to digital media and digital rights (Hartman et al...

Tunneling Flight Time, Chemistry, and Special Relativity.

Science.gov (United States)

Petersen, Jakob; Pollak, Eli

2017-09-07

Attosecond ionization experiments have not resolved the question "What is the tunneling time?". Different definitions of tunneling time lead to different results. Second, a zero tunneling time for a material particle suggests that the nonrelativistic theory includes speeds greater than the speed of light. Chemical reactions, occurring via tunneling, should then not be considered in terms of a nonrelativistic quantum theory calling into question quantum dynamics computations on tunneling reactions. To answer these questions, we define a new experimentally measurable paradigm, the tunneling flight time, and show that it vanishes for scattering through an Eckart or a square barrier, irrespective of barrier length or height, generalizing the Hartman effect. We explain why this result does not lead to experimental measurement of speeds greater than the speed of light. We show that this tunneling is an incoherent process by comparing a classical Wigner theory with exact quantum mechanical computations.

Joseph Smith's tritheism : the prophet's theology in context, critiqued from a Nicene perspective / Keith Dayton Hartman II

OpenAIRE

Hartman, Keith Dayton

2013-01-01

Joseph Smith is one of the most enigmatic figures in American religious history. From the details of his life story to the eventual formation of his own church, much has been written on the legacy of Joseph Smith. However, there are still numerous areas of Smith’s life and thought that demand further engagement, especially from a Nicene perspective. The purpose of the present research is to substantively add to scholarly knowledge regarding Joseph Smith. In contradistinction...

Numerical study of entropy generation and melting heat transfer on MHD generalised non-Newtonian fluid (GNF): Application to optimal energy

Science.gov (United States)

Iqbal, Z.; Mehmood, Zaffar; Ahmad, Bilal

2018-05-01

This paper concerns an application to optimal energy by incorporating thermal equilibrium on MHD-generalised non-Newtonian fluid model with melting heat effect. Highly nonlinear system of partial differential equations is simplified to a nonlinear system using boundary layer approach and similarity transformations. Numerical solutions of velocity and temperature profile are obtained by using shooting method. The contribution of entropy generation is appraised on thermal and fluid velocities. Physical features of relevant parameters have been discussed by plotting graphs and tables. Some noteworthy findings are: Prandtl number, power law index and Weissenberg number contribute in lowering mass boundary layer thickness and entropy effect and enlarging thermal boundary layer thickness. However, an increasing mass boundary layer effect is only due to melting heat parameter. Moreover, thermal boundary layers have same trend for all parameters, i.e., temperature enhances with increase in values of significant parameters. Similarly, Hartman and Weissenberg numbers enhance Bejan number.

Creativity at the Film-Making Club: Let there be light!

CERN Multimedia

2008-01-01

The Film-Making Club was created in 2005, and already has ten short films to its credit. Spotlight on a club that does more than making movies! Making a film requires solid teamwork and genuine commitment. In addition to shooting, which requires at least five people in key roles—plus the actors!—there is also the work of casting, location work, choice of equipment and techniques, logistics (hardware, costume design etc.) and post-production, which includes film editing and soundtrack.What does it take to make a film? "It involves a marriage of the power of the imagination, the technical constraints and the actors’ performances," explains Quentin King, the current president and founder of the club. "You need a real synthesis of art and technique," he adds. For club member Neal Hartman, "the French word réalisateur really reflects this aspect of the work, where you need to imagine something, then reconceptualise it in terms of its...

See you at the movies!

CERN Multimedia

Katarina Anthony

2012-01-01

The third edition of CinéGlobe, the international film festival founded at and hosted by CERN, will be taking place 27 March to 1 April. Some 55 short films will be shown in the Globe of Science and Innovation, all based around this year’s theme: “infinitely interconnected”.   Founded by members of CERN’s Film-making Club, CinéGlobe began in 2007 as a simple “friends and family” event for club members. “We turned our annual meetings into a screening event, showing off films we’d made over a year,” says Neal Hartman, a mechanical engineer who is president of the CERN-based filmmaker’s club OYE (Open Your Eyes Films) and is also the artistic director of the CineGlobe festival. “It was extremely popular and great fun, but the next year we just didn’t have enough new films to justify a screening. So, Jacques-Hervé Fichet – member of th...

Hall and ion slip effects on peristaltic flow of Jeffrey nanofluid with Joule heating

Energy Technology Data Exchange (ETDEWEB)

Hayat, T. [Department of Mathematics, Quaid-I-Azam University 45320, Islamabad 44000 (Pakistan); NAAM Research Group, Department of Mathematics, Faculty of Science, King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Shafique, Maryam [Department of Mathematics, Quaid-I-Azam University 45320, Islamabad 44000 (Pakistan); Tanveer, A., E-mail: anum@math.qau.edu.pk [Department of Mathematics, Quaid-I-Azam University 45320, Islamabad 44000 (Pakistan); Alsaedi, A. [NAAM Research Group, Department of Mathematics, Faculty of Science, King Abdulaziz University, Jeddah 21589 (Saudi Arabia)

2016-06-01

This paper addresses mixed convective peristaltic flow of Jeffrey nanofluid in a channel with complaint walls. The present investigation includes the viscous dissipation, thermal radiation and Joule heating. Hall and ion slip effects are also taken into account. Related problems through long wavelength and low Reynolds number are examined for stream function, temperature and concentration. Impacts of thermal radiation, Hartman number, Brownian motion parameter, thermophoresis, Joule heating, Hall and ion slip parameters are investigated in detail. It is observed that velocity increases and temperature decreases with Hall and ion slip parameters. Further the thermal radiation on temperature has qualitatively similar role to that of Hall and ion slip effects. - Highlights: • Peristalsis in the presence of Jeffery nanofluid is formulated. • Compliant properties of channel walls are addressed. • Impact of Hall and ion slip effects is outlined. • Influence of Joule heating and radiation is investigated. • Mixed convection for both heat and mass transfer is present.

Numerical Investigation of Fluid Flow and Heat Transfer Inside a 2D Enclosure with Three Hot Obstacles on the Ramp under the Influence of a Magnetic Field

Directory of Open Access Journals (Sweden)

M. M. Keshtkar

2017-06-01

Full Text Available This paper focuses on solving the fluid flow and heat transfer equations inside a two-dimensional square enclosure containing three hot obstacles affected by gravity and magnetic force placed on a ramp using Boltzmann method (LBM applying multiple relaxation times (MRT. Although, the Lattice Boltzmann with MRT is a complex technique, it is a relatively new, stable, fast and high-accurate one. The main objective of this research was to numerically model the fluid flow and ultimately obtaining the velocity field, flow and temperature contour lines inside a two-dimensional enclosure. The results and their comparisons for different types of heat transfer revealed that free or forced heat transfer has a considerable impact on the heat transfer and stream lines. This can be controlled by modifying the Richardson number. It is revealed that changing the intensity of the magnetic field (Hartman number has an appreciable effect on the heat transfer.

Analysis of the Magnetic Field Effect on Entropy Generation at Thermosolutal Convection in a Square Cavity

Directory of Open Access Journals (Sweden)

Ammar Ben Brahim

2011-05-01

Full Text Available Thermosolutal convection in a square cavity filled with air and submitted to an inclined magnetic field is investigated numerically. The cavity is heated and cooled along the active walls with a mass gradient whereas the two other walls of the cavity are adiabatic and insulated. Entropy generation due to heat and mass transfer, fluid friction and magnetic effect has been determined in transient state for laminar flow by solving numerically the continuity, momentum energy and mass balance equations, using a Control Volume Finite—Element Method. The structure of the studied flows depends on four dimensionless parameters which are the Grashof number, the buoyancy ratio, the Hartman number and the inclination angle. The results show that the magnetic field parameter has a retarding effect on the flow in the cavity and this lead to a decrease of entropy generation, Temperature and concentration decrease with increasing value of the magnetic field parameter.

Adenocarcinoma mucoproductor de colon con infiltración de estómago y metástasis ováricas (tumor de Krukenberg Colon mucoproducing adenocarcinoma with stomach infiltration and ovarian metastases (Krukenberg's tumor

Directory of Open Access Journals (Sweden)

Orestes Noel Mederos Curbelo

2011-12-01

Full Text Available Se presenta una paciente femenina de 29 años, operada de urgencia por presentar un gran tumor que incluía cuerpo gástrico y colon trasverso, con una perforación gástrica. Se realizó una gastrectomía subtotal con colectomía trasversa en bloque que incluyó el epiplón mayor. El diagnóstico histológico fue adenocarcinoma túbulo papilar mucoproductor de origen colónico, que infiltra hasta la serosa y pared gástrica. Se realizó tratamiento adyuvante con poliquimioterapia. Diez meses después presenta un tumor en hipogastrio, que al tacto vaginal, correspondía a los órganos genitales, sospecha clínica que confirman el ultrasonido abdominal y la tomografía axial computarizada. El hallazgo transoperatorio fueron tumores voluminosos de ambos ovarios, y otro tumor que afectaba la unión rectosigmoide. Se realizó una histerectomía radical con ooforectomía bilateral y sigmoidectomía, se reseca la porción proximal del recto, y se cierra tipo Hartman. El diagnóstico histológico final fue metástasis en serosa uterina e intestinal, y en ambos ovarios de adenocarcinoma mucoproductor, túbulo papilar de intestino previamente diagnosticado (tumor de Krukenberg. Se complementó el tratamiento con poliquimioterapia adyuvante.This is the case of a woman aged 29 operated on of emergency due to a tumor involving gastric body and transverse colon with gastric perforation. A subtotal gastrectomy with block transverse colectomy including the greater omentum was carried out. The histological diagnosis was a mucoproducing papillary tubular adenocarcinoma of colonic origin infiltrating to serosa and gastric wall. An adjuvant treatment was applied with poly-chemotherapy. Ten months later appears a hypogastric tumor which at vaginal manual examination corresponding to genital organs, clinical suspicion confirmed by abdominal ultrasound and computerized axial tomography. The transoperative findings were bulky tumors of both ovaries and another tumor

Stay-cable vibration monitoring of the Fred Hartman Bridge (Houston, Texas) and the Veterans Memorial Bridge (Port Arthur, Texas).

Science.gov (United States)

2005-10-30

This report summarizes the accomplishments of a field investigation project that was conducted in order to understand the mechanisms of wind- and rain-wind-induced stay cable vibrations and to assess the effectiveness of passive viscous dampers and c...

Measurement of wavefront aberrations in cortex and peripheral nerve using a two-photon excitation guidestar

Science.gov (United States)

Futia, Gregory L.; Fontaine, Arjun; McCullough, Connor; Ozbay, Baris N.; George, Nickolas M.; Caldwell, John; Restrepo, Diego; Weir, Richard; Gibson, Emily A.

2018-02-01

Neural-machine interfaces using optogenetics are of interest due to their minimal invasiveness and potential for parallel read in and read out of activity. One possible biological target for such an interface is the peripheral nerve, where axonlevel imaging or stimulation could greatly improve interfacing with artificial limbs or enable neuron/fascicle level neuromodulation in the vagus nerve. Two-photon imaging has been successful in imaging brain activity using genetically encoded calcium or voltage indicators, but in the peripheral nerve, this is severely limited by scattering and aberrations from myelin. We employ a Shack-Hartman wavefront sensor and two-photon excitation guidestar to quantify optical scattering and aberrations in peripheral nerves and cortex. The sciatic and vagus nerves, and cortex from a ChAT-Cre ChR-eYFP transgenic mouse were excised and imaged directly. In peripheral nerves, defocus was the strongest aberration followed by astigmatism and coma. Peripheral nerve had orders of magnitude higher aberration compared with cortex. These results point to the potential of adaptive optics for increasing the depth of two-photon access into peripheral nerves.

Stability of plane Poiseuille flow of viscoelastic fluids in the presence of a transverse magnetic field

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Hifdi Ahmed

2012-07-01

Full Text Available The linear stability of plan Poiseuille flow of an electrically conducting viscoelastic fluid in the presence of a transverse magnetic field is investigated numerically. The fourth-order Sommerfeld equation governing the stability analysis is solved by spectral method with expansions in lagrange’s polynomials, based on collocation points of Gauss-Lobatto. The critical values of Reynolds number, wave number and wave speed are computed. The results are shown through the neutral curve. The main purpose of this work is to check the combined effect of magnetic field and fluid’s elasticity on the stability of the plane Poiseuille flow. Based on the results obtained in this work, the magnetic field is predicted to have a stabilizing effect on the Poiseuille flow of viscoelastic fluids. Hence, it will be shown that for second-order fluids (K 0 is that the critical Reynolds numbers Rec increase when the Hartman number M increases for certain value of elasticity number K and decrease for others. The latter result is in contrast to previous studies.

Towards causal patch physics in dS/CFT

Science.gov (United States)

Neiman, Yasha

2018-01-01

This contribution is a status report on a research program aimed at obtaining quantum-gravitational physics inside a cosmological horizon through dS/CFT, i.e. through a holographic description at past/future infinity of de Sitter space. The program aims to bring together two main elements. The first is the observation by Anninos, Hartman and Strominger that Vasiliev's higher-spin gravity provides a working model for dS/CFT in 3+1 dimensions. The second is the proposal by Parikh, Savonije and Verlinde that dS/CFT may prove more tractable if one works in so-called "elliptic" de Sitter space - a folded-in-half version of global de Sitter where antipodal points have been identified. We review some relevant progress concerning quantum field theory on elliptic de Sitter space, higher-spin gravity and its holographic duality with a free vector model. We present our reasons for optimism that the approach outlined here will lead to a full holographic description of quantum (higher-spin) gravity in the causal patch of a de Sitter observer.

Bounds and enhancements for negative scattering time delays

International Nuclear Information System (INIS)

Muga, J.G.; Egusquiza, I.L.; Damborenea, J.A.; Delgado, F.

2002-01-01

The time of passage of the transmitted wave packet in a tunneling collision of a quantum particle with a square potential barrier becomes independent of the barrier width in a range of barrier thickness. This is the Hartman effect, which has been frequently associated with 'superluminality'. A fundamental limitation on the effect is set by nonrelativistic 'causality conditions'. We demonstrate first that the causality conditions impose more restrictive bounds on the negative time delays (time advancements) when no bound states are present. These restrictive bounds are in agreement with a naive, and generally false, causality argument based on the positivity of the 'extrapolated phase time', one of the quantities proposed to characterize the duration of the barrier's traversal. Nevertheless, square wells may in fact lead to much larger advancements than square barriers. We point out that close to the thresholds of new bound states, the time advancement increases considerably, while, at the same time, the transmission probability is large, which facilitates the possible observation of the enhanced time advancement

Framing the performance of heat absorption/generation and thermal radiation in chemically reactive Darcy-Forchheimer flow

Directory of Open Access Journals (Sweden)

T. Hayat

Full Text Available The present work aims to report the consequences of heterogeneous-homogeneous reactions in Darcy-Forchheimer flow of Casson material bounded by a nonlinear stretching sheet of variable thickness. Nonlinear stretched surface with variable thickness is the main agent for MHD Darcy-Forchheimer flow. Impact of thermal radiation and non-uniform heat absorption/generation are also considered. Flow in porous space is characterized by Darcy-Forchheimer flow. It is assumed that the homogeneous process in ambient fluid is governed by first order kinetics and the heterogeneous process on the wall surface is given by isothermal cubic autocatalator kinetics. The governing nonlinear ordinary differential equations are solved numerically. Effects of physical variables such as thickness, Hartman number, inertia and porous, radiation, Casson, heat absorption/generation and homogeneous-heterogeneous reactions are investigated. The variations of drag force (skin friction and heat transfer rate (Nusselt numberfor different interesting variables are plotted and discussed. Keywords: Casson fluid, Variable sheet thickness, Darcy-Forchheimer flow, Homogeneous-heterogeneous reactions, Heat generation/absorption, Thermal radiation

Outcome of homogeneous and heterogeneous reactions in Darcy-Forchheimer flow with nonlinear thermal radiation and convective condition

Directory of Open Access Journals (Sweden)

T. Hayat

Full Text Available The present analysis aims to report the consequences of nonlinear radiation, convective condition and heterogeneous-homogeneous reactions in Darcy-Forchheimer flow over a non-linear stretching sheet with variable thickness. Non-uniform magnetic field and nonuniform heat generation/absorption are accounted. The governing boundary layer partial differential equations are converted into a system of nonlinear ordinary differential equations. The computations are organized and the effects of physical variables such as thickness parameter, power index, Hartman number, inertia and porous parameters, radiation parameter, Biot number, Prandtl number, ratio parameter, heat generation parameter and homogeneous-heterogeneous reaction parameter are investigated. The variations of skin friction coefficient and Nusselt number for different interesting variables are plotted and discussed. It is noticed that Biot number and heat generation variable lead to enhance the temperature distribution. The solutal boundary layer thickness decreases for larger homogeneous variable while reverse trend is seen for heterogeneous reaction. Keywords: Variable sheet thickness, Darcy-Forchheimer flow, Homogeneous-heterogeneous reactions, Power-law surface velocity, Convective condition, Heat generation/absorption, Nonlinear radiation

Mensuração de Atitude: Proposição de Um Protocolo de Elaboração de Escalas

Directory of Open Access Journals (Sweden)

Rafael Lucian

2015-08-01

Full Text Available This theoretical essay aims to study how scales are developed and through which procedures they can be considered valid and suitable for use as legitimate scientific instruments. In this perspective, this paper’s objective was to develop a protocol for constructing scales to measure attitude. The proposed protocol is configured as a logical meeting of steps based on theorists such as Allport and Hartman (1925, Thurstone (1928, Likert (1932, Campbell and Fiske (1959 and Bock (1972, which permeate all aspects of drafting scales, including construct definition, the choice of the scale itself, item preparation, scale purification, and finally its validation. At the end of the study, we present a protocol for the preparation of specific scales to measure attitude that differs from existing protocols in Churchill (1979, Rossiter (2002 and DeVellis (2003. This is in order to unite for the first time a set of promising techniques, primarily the objective delineation of the construct using focus group methodology, the proposition of an inherently dichotomous scale, scale purification via item response theory (IRT, and predictive validity.

Noiseless imaging detector for adaptive optics with kHz frame rates

CERN Document Server

Vallerga, J V; Mikulec, Bettina; Tremsin, A; Clark, Allan G; Siegmund, O H W; CERN. Geneva

2004-01-01

A new hybrid optical detector is described that has many of the attributes desired for the next generation AO wavefront sensors. The detector consists of a proximity focused MCP read out by four multi-pixel application specific integrated circuit (ASIC) chips developed at CERN (â€ﾜMedipix2”) with individual pixels that amplify, discriminate and count input events. The detector has 512 x 512 pixels, zero readout noise (photon counting) and can be read out at 1 kHz frame rates. The Medipix2 readout chips can be electronically shuttered down to a temporal window of a few microseconds with an accuracy of 10 nanoseconds. When used in a Shack-Hartman style wavefront sensor, it should be able to centroid approximately 5000 spots using 7 x 7 pixel sub-apertures resulting in very linear, off-null error correction terms. The quantum efficiency depends on the optical photocathode chosen for the bandpass of interest. A three year development effort for this detector technology has just been funded as part of the...

Modeling and analysis of biomagnetic blood Carreau fluid flow through a stenosis artery with magnetic heat transfer: A transient study.

Science.gov (United States)

Abdollahzadeh Jamalabadi, Mohammad Yaghoub; Daqiqshirazi, Mohammadreza; Nasiri, Hossein; Safaei, Mohammad Reza; Nguyen, Truong Khang

2018-01-01

We present a numerical investigation of tapered arteries that addresses the transient simulation of non-Newtonian bio-magnetic fluid dynamics (BFD) of blood through a stenosis artery in the presence of a transverse magnetic field. The current model is consistent with ferro-hydrodynamic (FHD) and magneto-hydrodynamic (MHD) principles. In the present work, blood in small arteries is analyzed using the Carreau-Yasuda model. The arterial wall is assumed to be fixed with cosine geometry for the stenosis. A parametric study was conducted to reveal the effects of the stenosis intensity and the Hartman number on a wide range of flow parameters, such as the flow velocity, temperature, and wall shear stress. Current findings are in a good agreement with recent findings in previous research studies. The results show that wall temperature control can keep the blood in its ideal blood temperature range (below 40°C) and that a severe pressure drop occurs for blockages of more than 60 percent. Additionally, with an increase in the Ha number, a velocity drop in the blood vessel is experienced.

Magnetized gun experiments

International Nuclear Information System (INIS)

Jarboe, T.R.; Henins, I.; Hoida, H.W.; Marshall, J.; Sherwood, A.R.

1981-01-01

In the Los Alamos Magnetized Gun Experiment we are attempting to produce a compact torus in a manner similar to an earlier experiment of Alfven. In our experiment a solenoidal coil is placed inside the inner electrode of a coaxial plasma gun. This coil produces an axial magnetic field inside the inner electrode which diverges and becomes a largely radial field in front of the gun muzzle. The idea is that when the gun is fired, the plasma escaping from the gun stretches these radial fields along the axial direction away from the gun, and these field lines can reconnect behind the plasma forming the poloidal field of the compact torus. The magnetic field generated by the gun current becomes the toroidal field and the major axis of the compact torus will be the same as the axis of the coaxial gun. Recent interest in this possible method of compact torus generation was stimulated by C. Hartman, and the approach is also being pursued in the field-reversed plasma gun experiment at LLL

An FPGA Architecture for Extracting Real-Time Zernike Coefficients from Measured Phase Gradients

Science.gov (United States)

Moser, Steven; Lee, Peter; Podoleanu, Adrian

2015-04-01

Zernike modes are commonly used in adaptive optics systems to represent optical wavefronts. However, real-time calculation of Zernike modes is time consuming due to two factors: the large factorial components in the radial polynomials used to define them and the large inverse matrix calculation needed for the linear fit. This paper presents an efficient parallel method for calculating Zernike coefficients from phase gradients produced by a Shack-Hartman sensor and its real-time implementation using an FPGA by pre-calculation and storage of subsections of the large inverse matrix. The architecture exploits symmetries within the Zernike modes to achieve a significant reduction in memory requirements and a speed-up of 2.9 when compared to published results utilising a 2D-FFT method for a grid size of 8×8. Analysis of processor element internal word length requirements show that 24-bit precision in precalculated values of the Zernike mode partial derivatives ensures less than 0.5% error per Zernike coefficient and an overall error of RAM usage is <16% for Shack-Hartmann grid sizes up to 32×32.

The effect of simulated inflammatory conditions on the surface properties of titanium and stainless steel and their importance as biomaterials

International Nuclear Information System (INIS)

Fonseca-García, Abril; Pérez-Alvarez, J.; Barrera, C.C.; Medina, J.C.; Almaguer-Flores, A.; Sánchez, R. Basurto

2016-01-01

This work compares the surface modifications induced by the immersion in solutions that simulate inflammatory conditions of pure titanium (cpTi) and medical grade stainless steel (SS). The inflammatory conditions were simulated using a mixture of Hartman solution and 50 mM of hydrogen peroxide (H_2O_2) at pH = 5.2. The samples were immersed by 7 days refreshing the solution every day to keep the reactivity of the H_2O_2. The surface characteristics that were investigated were: elemental composition by X-ray photoelectron spectroscopy (XPS); topography by atomic force microscopy (AFM) and profilometry; wettability and surface energy by sessile drop contact angle and point of zero charge by titration. Moreover, the variations in the electrochemical response were evaluated by open circuit potential (OCP), electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PP) performed before and after the treatment using the Hartman solution as the electrolyte. The XPS results indicated that for both metallic samples, oxidation of the surface was promoted and/or the oxide layer was thicker after the immersion. The roughness and the solid-liquid surface energy were increased; the samples showed a more hydrophilic character after the treatment. However, the surface energy of the solid estimated using the Van Oss–Chaudhury–Good approach showed different trends between the cpTi and the SS surfaces; the polar component decreased for cpTi, while it increased for SS. Finally, the electrochemical results indicated that the corrosion resistance (R_c_o_r) and the pore resistance (R_p_o) significantly decreased for cpTi, while both resistances were not significantly different for the SS. This is indicative of a higher dissolution of the cpTi compared to SS and the lower R_p_o means that the species are easily transported through the surface layer, which can be explained in terms of the formation of a porous TiO_x layer, not observed on the SS. The cpTi surface

The effect of simulated inflammatory conditions on the surface properties of titanium and stainless steel and their importance as biomaterials

Energy Technology Data Exchange (ETDEWEB)

Fonseca-García, Abril [Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, México (Mexico); Posgrado en Ciencia e Ingeniería de Materiales, Universidad Nacional Autónoma de México, México (Mexico); Pérez-Alvarez, J. [Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, México (Mexico); Barrera, C.C. [Posgrado en Ciencias Médicas, Odontológicas y de la Salud, Universidad Nacional Autónoma de México, México (Mexico); Medina, J.C. [Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, México (Mexico); Posgrado en Ciencia e Ingeniería de Materiales, Universidad Nacional Autónoma de México, México (Mexico); Almaguer-Flores, A. [Facultad de Odontología, Universidad Nacional Autónoma de México, México (Mexico); Sánchez, R. Basurto [Instituto Nacional de Investigaciones Nucleares, México (Mexico); and others

2016-09-01

This work compares the surface modifications induced by the immersion in solutions that simulate inflammatory conditions of pure titanium (cpTi) and medical grade stainless steel (SS). The inflammatory conditions were simulated using a mixture of Hartman solution and 50 mM of hydrogen peroxide (H{sub 2}O{sub 2}) at pH = 5.2. The samples were immersed by 7 days refreshing the solution every day to keep the reactivity of the H{sub 2}O{sub 2}. The surface characteristics that were investigated were: elemental composition by X-ray photoelectron spectroscopy (XPS); topography by atomic force microscopy (AFM) and profilometry; wettability and surface energy by sessile drop contact angle and point of zero charge by titration. Moreover, the variations in the electrochemical response were evaluated by open circuit potential (OCP), electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PP) performed before and after the treatment using the Hartman solution as the electrolyte. The XPS results indicated that for both metallic samples, oxidation of the surface was promoted and/or the oxide layer was thicker after the immersion. The roughness and the solid-liquid surface energy were increased; the samples showed a more hydrophilic character after the treatment. However, the surface energy of the solid estimated using the Van Oss–Chaudhury–Good approach showed different trends between the cpTi and the SS surfaces; the polar component decreased for cpTi, while it increased for SS. Finally, the electrochemical results indicated that the corrosion resistance (R{sub cor}) and the pore resistance (R{sub po}) significantly decreased for cpTi, while both resistances were not significantly different for the SS. This is indicative of a higher dissolution of the cpTi compared to SS and the lower R{sub po} means that the species are easily transported through the surface layer, which can be explained in terms of the formation of a porous TiO{sub x} layer, not

Tunnelling of a molecule

International Nuclear Information System (INIS)

Jarvis, P.D.; Bulte, D.P.

1998-01-01

A quantum-mechanical description of tunnelling is presented for a one-dimensional system with internal oscillator degrees of freedom. The 'charged diatomic molecule' is frustrated on encountering a barrier potential by its centre of charge not being coincident with its centre of mass, resulting in transitions amongst internal states. In an adiabatic limit, the tunnelling of semiclassical coherent-like oscillator states is shown to exhibit the Hartman and Bueuttiker-Landauer times t H and t BL , with the time dependence of the coherent state parameter for the tunnelled state given by α(t) = α e -iω(t+Δt) , Δt = t H - it BL . A perturbation formalism is developed, whereby the exact transfer matrix can be expanded to any desired accuracy in a suitable limit. An 'intrinsic' time, based on the oscillator transition rate during tunnelling, transmission or reflection, is introduced. In simple situations the resulting intrinsic tunnelling time is shown to vanish to lowest order. In the general case a particular (nonzero) parametrisation is inferred, and its properties discussed in comparison with the literature on tunnelling times for both wavepackets and internal clocks. Copyright (1998) CSIRO Australia

MOD-RTG multicouple test results and mission readiness

International Nuclear Information System (INIS)

Hartman, R.F.; Kelly, C.E.

1993-01-01

MOD-RTG represents the design configuration for the next generation of Radioisotope Thermoelectric Generators (RTG), aimed at improving specific power and efficiency over current General Purpose Heat Source Radioisotope Thermoelectric Generators (GPHS-RTGs). The modular RTG reference design has been described in previous papers (Hartman 1988). The multicouple is a key element required for the successful development of the modular RTG. The multicouple is a high voltage, thermoelectric device employing a close packed, glass bonded thermopile array of twenty thermoelectric couples, connected in a series circuit. The multicouple is designed to operate at a 1270 K hot junction temperature and a 570 K cold junction temperature, yielding a power output of approximately 2.1 watts at 3.5 volts at beginning of life. The objectives of the MOD-RTG program are focused on establishing a multicouple life test data base and life prediction capability which will permit, with reasonable margin, a projected multicouple life of greater than eight (8) years. This paper summarizes the current status of multicouple life testing and performance modeling and the level of technology readiness needed to demonstrate mission readiness for MOD-RTG

New Knowledge of tunneling from photonic experiments

International Nuclear Information System (INIS)

Nimtz, G.

1997-01-01

Photonic experiments have shown, that the propagation of evanescent (tunneling) modes can proceed at speeds faster than the velocity of light in vacuum (superluminal). The superluminal velocities include signal and energy propagation. The analogy between the classical Helmholtz equation and the quantum mechanical Schroedinger equation was quantitatively proved in classical photonic experiments. The Hartman effect, i.e. the prediction that the tunneling time is independent of the barrier length was for the first time evidenced in a photonic analogous tunneling experiment by Enders and Nimtz. It is also shown, that the resonant state life time is not determined by the barrier traversal time. For electronic tunneling devices it follows, that the quantum mechanical phase time calculations indeed deliver the relevant intrinsic tunneling time and consequently allow to predict the dynamical specification of a device. The present theoretical descriptions of the propagation of evanescent modes is not fully compatible with the experimental situation. Superluminal signal and energy transport has been measured, and this has to be properly analyzed. May the advanced field solutions help to obtain a satisfactory theoretical description of the recent experimental results of the propagation of evanescent modes? (author)

Numerical simulation of effects of a non-ionized fluid injection and suction on the MHD flow in a circular channel

International Nuclear Information System (INIS)

Rahimi Eosboee, M.; Pourmahmoud, N.; Mirzaie, I.; Mohajeri Khameneh, P.; Majidyfar, S.

2012-01-01

Control of a fluid flow velocity profile by injection and suction of a non-ionized fluid in presence of a uniform steady magnetic field has important technical applications. In this paper, the unsteady incompressible and viscous conducting fluid flow has been investigated in a circular channel. The channel walls are assumed to be non-conducting and porous. They are subjected to a uniform steady magnetic field which is perpendicular to the axis of channel, then and suction and injection are applied at the walls. The well known equations of Magnetohydrodynamics are governed to the motion of an electrically conducting fluid flow that is subjected to magnetic field. The numerical solution is carried out by finite difference approach. The results of present numerical simulation shown that the flow injection and suction through the wall can be controlled effectively, the main flow in channel especially in industrial purposes. The results are obtained for different values of the injected and sucked non-ionized flow rate and the effect of Hartman number on the velocity profile is investigated. Finally, a good agreement is seen between the presented results and the corresponding data of finite element method.

Physical aspects of heat generation/absorption in the second grade fluid flow due to Riga plate: Application of Cattaneo-Christov approach

Science.gov (United States)

Anjum, Aisha; Mir, N. A.; Farooq, M.; Javed, M.; Ahmad, S.; Malik, M. Y.; Alshomrani, A. S.

2018-06-01

The present article concentrates on thermal stratification in the flow of second grade fluid past a Riga plate with linear stretching towards a stagnation region. Heat transfer phenomenon is disclosed with heat generation/absorption. Riga plate is known as electromagnetic actuator which comprises of permanent magnets and alternating electrodes placed on a plane surface. Cattaneo-Christov heat flux model is implemented to analyze the features of heat transfer. This new heat flux model is the generalization of classical Fourier's law with the contribution of thermal relaxation time. For the first time heat generation/absorption effect is computed with non-Fourier's law of heat conduction (i.e., Cattaneo-Christov heat flux model). Transformations are used to obtain the governing non-linear ordinary differential equations. Approximate convergent solutions are developed for the non-dimensionalized governing problems. Physical features of velocity and temperature distributions are graphically analyzed corresponding to various parameters in 2D and 3D. It is noted that velocity field enhances with an increment of modified Hartman number while it reduces with increasing variable thickness parameter. Increment in modified heat generation parameter results in reduction of temperature field.

Impact of radial magnetic field on peristalsis in curved channel with convective boundary conditions

Energy Technology Data Exchange (ETDEWEB)

Hayat, Tasawar [Department of Mathematics, Quaid-I-Azam University 45320, Islamabad 44000 (Pakistan); Department of Electrical and Computer Engineering, Faculty of Engineering, King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Tanveer, Anum, E-mail: qau14@yahoo.com [Department of Mathematics, Quaid-I-Azam University 45320, Islamabad 44000 (Pakistan); Alsaadi, Fuad [Department of Electrical and Computer Engineering, Faculty of Engineering, King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Mousa, Ghassan [Department of Mechanical Engineering, Faculty of Engineering, King Abdulaziz University, Jeddah 21589 (Saudi Arabia)

2016-04-01

This paper addresses the peristaltic flow in curved channel with combined heat/mass transfer and convective effects. The channel walls are flexible. An imposed magnetic field is applied in radial direction to increase the wave amplitude (used in ECG for synchronization purposes). The pseudoplastic fluid comprising shear-thinning/shear thickening effects has been used in mathematical modeling. Small Reynolds number assumption is employed to neglect inertial effects. Half channel-width to wavelength ratio is small enough for the pressure to be considered uniform over the cross-section. The graphical results obtained are compared with planar channel. Results show the non-symmetric behavior of sundry parameters in contrary to the planar case. Additionally more clear results are seen when the curved channel is approached. - Highlights: • The behavior of curvature parameter k on velocity is not symmetric. • Temperature is decreasing function of Biot number Bi. • Hartman number has similar qualitative effects on both velocity and temperature. • Behavior of concentration is opposite to that of temperature in a qualitative sense. • Bolus size via curvature parameter has opposite effect near the upper and lower channel walls.

Angle Dependence of the Orbital Magnetoresistance in Bismuth

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Aurélie Collaudin

2015-06-01

Full Text Available We present an extensive study of angle-dependent transverse magnetoresistance in bismuth, with a magnetic field perpendicular to the applied electric current and rotating in three distinct crystallographic planes. The observed angular oscillations are confronted with the expectations of semiclassic transport theory for a multivalley system with anisotropic mobility and the agreement allows us to quantify the components of the mobility tensor for both electrons and holes. A quadratic temperature dependence is resolved. As Hartman argued long ago, this indicates that inelastic resistivity in bismuth is dominated by carrier-carrier scattering. At low temperature and high magnetic field, the threefold symmetry of the lattice is suddenly lost. Specifically, a 2π/3 rotation of magnetic field around the trigonal axis modifies the amplitude of the magnetoresistance below a field-dependent temperature. By following the evolution of this anomaly as a function of temperature and magnetic field, we map the boundary in the (field, temperature plane separating two electronic states. In the less symmetric state, confined to low temperature and high magnetic field, the three Dirac valleys cease to be rotationally invariant. We discuss the possible origins of this spontaneous valley polarization, including a valley-nematic scenario.

Full Phase Multi-Band Study of Eclipsing Binaries 1SWASP J061850.43+220511.9 and 2MASSJ07095549+3643564

Science.gov (United States)

Terheide, Rachel; Zhang, Liyun; Han, Xianming; Lu, Hongpeng

2018-01-01

We present full-phase VRI-band light curves for eclipsing binary 1SWASP J061850.43+220511.9, and full-phase BVRI-band light curves for eclipsing binary 2MASS J07095549+3643564. The observations were conducted using the 0.94-m Holcomb Observatory telescope located on Butler University Campus in Indianapolis, Indiana, and the 0.6-m SARA telescope located at the Cerro Tololo Inter-American Observatory in Chile. We obtained key system parameters for both eclipsing binaries. For 1SWASP J061850.43+220511.9, the period is 0.21482 ±0.00053 days compared to 0.21439 days from an older study (Lohr et. al), the system mass ratio is found as 2.50 and the system is classified as EW type. Similarly, for 2MASS J07095549+3643564, we obtained a linear ephemeris and a physical model for the first time. We found its period to be 0.22297 ±0.00032 days, as compared to 0.446092 days and 0.11152 days from previous research (Drake et. al 2014, Hartman et. al 2011). 2MASS J07095549+3643564 is classified as a W Uma type eclipsing binary.

Nonlinear convective flow of Powell-Erying magneto nanofluid with Newtonian heating

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Sajid Qayyum

Full Text Available Objective of present article is to describe magnetohydrodynamic (MHD non-linear convective flow of Powell-Erying nanofluid over a stretching surface. Characteristics of Newtonian heat and mass conditions in this attempt is given attention. Heat and mass transfer analysis is examined in the frame of thermal radiation and chemical reaction. Brownian motion and thermophoresis concept is introduced due to presence of nanoparticles. Nonlinear equations of momentum, energy and concentration are transformed into dimensionless expression by invoking suitable variables. The series solutions are obtained through homotopy analysis method (HAM. Impact of embedded variables on the velocity, temperature and nanoparticles concentration is graphically presented. Numerical values of skin friction coefficient, local Nusselt and Sherwood numbers are computed and analyzed. It is concluded that velocity field enhances for fluid variable while reverse situation is noticed regarding Hartman number. Temperature and heat transfer rate behave quite reverse for Prandtl number. It is also noted that the concentration and local Sherwood number have opposite behavior in the frame of Brownian motion. Keywords: Powell-Erying nanofluid, Magnetohydrodynamic (MHD, Nonlinear convection, Thermal radiation, Chemical reaction, Newtonian heat and mass conditions

Transient electro-magneto-hydrodynamic two-phase blood flow and thermal transport through a capillary vessel.

Science.gov (United States)

Mirza, I A; Abdulhameed, M; Vieru, D; Shafie, S

2016-12-01

Therapies with magnetic/electromagnetic field are employed to relieve pains or, to accelerate flow of blood-particles, particularly during the surgery. In this paper, a theoretical study of the blood flow along with particles suspension through capillary was made by the electro-magneto-hydrodynamic approach. Analytical solutions to the non-dimensional blood velocity and non-dimensional particles velocity are obtained by means of the Laplace transform with respect to the time variable and the finite Hankel transform with respect to the radial coordinate. The study of thermally transfer characteristics is based on the energy equation for two-phase thermal transport of blood and particles suspension with viscous dissipation, the volumetric heat generation due to Joule heating effect and electromagnetic couple effect. The solution of the nonlinear heat transfer problem is derived by using the velocity field and the integral transform method. The influence of dimensionless system parameters like the electrokinetic width, the Hartman number, Prandtl number, the coefficient of heat generation due to Joule heating and Eckert number on the velocity and temperature fields was studied using the Mathcad software. Results are presented by graphical illustrations. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

THE OPTIMAL ROTATIONS OF GMELINA STAND ON TWO CARBON PROJECTS: LENGTHENING ROTATION AND AFFORESTATION

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Yonky Indrajaya

2016-12-01

Full Text Available Forest plantation may contribute economically and socially as a provider of wood raw materials for industry and providing jobs for local people. In addition, forest plantation may also contribute as watershed protection and carbon sequestration. Projects on carbon sequestration from plantation forest can be conducted in two types: (1 afforestation and (2 lengthening forest rotation. One of the potential carbon markets operationalized in the field is voluntary market with Verified Carbon Standard mechanism. This study aimed to analyze the optimal rotations of gmelina forests on two carbon projects: lengthening rotation and afforestation. The method used in this study was by using Hartman model ( i.e. Faustmann by maximizing profit with the revenue source from timber and carbon sequestration project. The results of this study showed that carbon price will affect the optimal rotation for lengthening forest rotation of VCS project. Meanwhile, for VCS afforestation project, carbon price had no effect on the optimal rotation on gmelina forest. The NPV value of afforestation project was relatively higher than that of NPV value of lengthening forest rotation project, since the amount of carbon that can be credited relatively higher in afforestation project.

Simulated human eye retina adaptive optics imaging system based on a liquid crystal on silicon device

International Nuclear Information System (INIS)

Jiang Baoguang; Cao Zhaoliang; Mu Quanquan; Hu Lifa; Li Chao; Xuan Li

2008-01-01

In order to obtain a clear image of the retina of model eye, an adaptive optics system used to correct the wave-front error is introduced in this paper. The spatial light modulator that we use here is a liquid crystal on a silicon device instead of a conversional deformable mirror. A paper with carbon granule is used to simulate the retina of human eye. The pupil size of the model eye is adjustable (3-7 mm). A Shack–Hartman wave-front sensor is used to detect the wave-front aberration. With this construction, a value of peak-to-valley is achieved to be 0.086 λ, where λ is wavelength. The modulation transfer functions before and after corrections are compared. And the resolution of this system after correction (691p/m) is very close to the dirraction limit resolution. The carbon granule on the white paper which has a size of 4.7 μm is seen clearly. The size of the retina cell is between 4 and 10 mu;m. So this system has an ability to image the human eye's retina. (classical areas of phenomenology)

Effects of buoyancy and thermal radiation on MHD flow over a stretching porous sheet using homotopy analysis method

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Yahaya Shagaiya Daniel

2015-09-01

Full Text Available This paper investigates the theoretical influence of buoyancy and thermal radiation on MHD flow over a stretching porous sheet. The model which constituted highly nonlinear governing equations is transformed using similarity solution and then solved using homotopy analysis method (HAM. The analysis is carried out up to the 5th order of approximation and the influences of different physical parameters such as Prandtl number, Grashof number, suction/injection parameter, thermal radiation parameter and heat generation/absorption coefficient and also Hartman number on dimensionless velocity, temperature and the rate of heat transfer are investigated and discussed quantitatively with the aid of graphs. Numerical results obtained are compared with the previous results published in the literature and are found to be in good agreement. It was found that when the buoyancy parameter and the fluid velocity increase, the thermal boundary layer decreases. In case of the thermal radiation, increasing the thermal radiation parameter produces significant increases in the thermal conditions of the fluid temperature which cause more fluid in the boundary layer due to buoyancy effect, causing the velocity in the fluid to increase. The hydrodynamic boundary layer and thermal boundary layer thickness increase as a result of increase in radiation.

The patients’ perspective: Results of a survey assessing knowledge about and attitudes toward depression in PD

Directory of Open Access Journals (Sweden)

Irene Hegeman Richard

2007-01-01

Full Text Available Irene Hegeman Richard1, Kori A LaDonna1, Rosanne Hartman2, Carol Podgorski1, Roger Kurlan1, SAD-PD Study Group31University of Rochester School of Medicine and Dentistry, Rochester, NY, USA; 2Canisius College, Buffalo, NY, USA; 3Please see Appendix for members of the SAD-PD Study GroupAbstract: We report results of a survey assessing patients’ knowledge about and attitudes towards depression in Parkinson’s disease (PD. 345 patients from 8 tertiary care centers responded (43% response rate. Overall, patients were relatively knowledgeable about depression and its occurrence in PD. However, many patients believed that depression is a normal reaction to the illness. While many respondents would be reluctant to initiate a discussion of depression during a clinical evaluation, most would feel comfortable talking about depression with their physician if he or she asked them questions about their mood. Based on the results of this survey, we recommend the following approach for physicians: (1 inform PD patients that, although a frequent occurrence, depression need not be accepted as a “normal reaction” to PD; and (2 routinely inquire about depressive symptoms rather than waiting for the patient to spontaneously report them.Keywords: depression, Parkinson’s disease, survey

Evolution of a wave packet scattered by a one-dimensional potential

International Nuclear Information System (INIS)

Khachatrian, A Zh; Alexanyan, Al G; Khoetsyan, V A; Alexanyan, N A

2013-01-01

We consider the evolution of a wave packet that is made up of a group of the wave functions describing the stationary scattering process and tunnels through a one-dimensional potential of arbitrary form. As the main characteristics of the time difference of the tunnelling process, use is made of the propagation speed of the wave-packet maximum. We show that the known Hartman formula for the tunnelling time corresponds to the wave packet with a wavenumber-uniform spectral composition in the case, when the phase and transmission coefficient modulus dispersions are taken into account only in the linear approximation. The amplitude of the main peak of the transmitted wave intensity is proven to be independent of the tunnelling time and is determined by the transmission coefficient of the spectral component at the carrier frequency and the spectral width of the wave packet. In the limit of an infinitely wide potential barrier the amplitude of the wave-packet maximum is shown to tend to zero slower than the tunnelling time tends to its asymptotic value, i.e., indeed we deal with the paradox of an infinitely large propagation speed of a wave disturbance through the barrier. (propagation of wave fronts)

Evolution of a wave packet scattered by a one-dimensional potential

Energy Technology Data Exchange (ETDEWEB)

Khachatrian, A Zh; Alexanyan, Al G; Khoetsyan, V A; Alexanyan, N A

2013-06-30

We consider the evolution of a wave packet that is made up of a group of the wave functions describing the stationary scattering process and tunnels through a one-dimensional potential of arbitrary form. As the main characteristics of the time difference of the tunnelling process, use is made of the propagation speed of the wave-packet maximum. We show that the known Hartman formula for the tunnelling time corresponds to the wave packet with a wavenumber-uniform spectral composition in the case, when the phase and transmission coefficient modulus dispersions are taken into account only in the linear approximation. The amplitude of the main peak of the transmitted wave intensity is proven to be independent of the tunnelling time and is determined by the transmission coefficient of the spectral component at the carrier frequency and the spectral width of the wave packet. In the limit of an infinitely wide potential barrier the amplitude of the wave-packet maximum is shown to tend to zero slower than the tunnelling time tends to its asymptotic value, i.e., indeed we deal with the paradox of an infinitely large propagation speed of a wave disturbance through the barrier. (propagation of wave fronts)

An O([Formula: see text]) algorithm for sorting signed genomes by reversals, transpositions, transreversals and block-interchanges.

Science.gov (United States)

Yu, Shuzhi; Hao, Fanchang; Leong, Hon Wai

2016-02-01

We consider the problem of sorting signed permutations by reversals, transpositions, transreversals, and block-interchanges. The problem arises in the study of species evolution via large-scale genome rearrangement operations. Recently, Hao et al. gave a 2-approximation scheme called genome sorting by bridges (GSB) for solving this problem. Their result extended and unified the results of (i) He and Chen - a 2-approximation algorithm allowing reversals, transpositions, and block-interchanges (by also allowing transversals) and (ii) Hartman and Sharan - a 1.5-approximation algorithm allowing reversals, transpositions, and transversals (by also allowing block-interchanges). The GSB result is based on introduction of three bridge structures in the breakpoint graph, the L-bridge, T-bridge, and X-bridge that models goodreversal, transposition/transreversal, and block-interchange, respectively. However, the paper by Hao et al. focused on proving the 2-approximation GSB scheme and only mention a straightforward [Formula: see text] algorithm. In this paper, we give an [Formula: see text] algorithm for implementing the GSB scheme. The key idea behind our faster GSB algorithm is to represent cycles in the breakpoint graph by their canonical sequences, which greatly simplifies the search for these bridge structures. We also give some comparison results (running time and computed distances) against the original GSB implementation.

VizieR Online Data Catalog: Pleiades members stellar properties (Somers+, 2017)

Science.gov (United States)

Somers, G.; Stassun, K. G.

2018-04-01

We began with the newly assembled catalog of literature lithium measurements reported by Barrado et al. (2016, J/A+A/596/A113), who accepted only stars with membership probability >0.75. A small number of Pleiads lie behind an HI cloud, and are thus far more extincted than the rest (e.g., Gordon & Arny 1984AJ.....89..672G); for simplicity, we discard these members. We then cross-correlated this sample with the famous UBV photometric catalog of Johnson & Mitchell (1958ApJ...128...31J), who produced homogeneous photometry for a large sample of Pleiades members. We further selected stars with measured rotation rates, either from the HATNet collaboration (Hartman et al. 2010, J/MNRAS/408/475), or the recent analysis of K2 data (Rebull et al. 2016, J/AJ/152/113, J/AJ/152/114; Stauffer et al. 2016, J/AJ/152/115), preferring the latter for joint detections. Finally, we queried VizieR (http://vizier.u-strasbg.fr/) to obtain KS-band magnitudes from the Two-Micron All-Sky Survey (2MASS) catalog (Skrutskie et al. 2006, Cat. VII/233), which detected every star in our reduced sample. These criteria produced a total of 83 high-probability cluster members, stretching from early-F to late-K type. (3 data files).

Energy Levels, wavelengths and hyperfine structure measurements of Sc II

Science.gov (United States)

Hala, Fnu; Nave, Gillian

2018-01-01

Lines of singly ionized Scandium (Sc II) along with other Iron group elements have been observed [1] in the region surrounding the massive star Eta Carinae [2,3] called the strontium filament (SrF). The last extensive analysis of Sc II was the four-decade old work of Johansson & Litzen [4], using low-resolution grating spectroscopy. To update and extend the Sc II spectra, we have made observation of Sc/Ar, Sc/Ne and Sc/Ge/Ar hollow cathode emission spectrum on the NIST high resolution FT700 UV/Vis and 2 m UV/Vis/IR Fourier transform spectrometers (FTS). More than 850 Sc II lines have been measured in the wavelength range of 187 nm to 3.2 μm. connecting a total of 152 energy levels. The present work also focuses to resolve hyperfine structure (HFS) in Sc II lines. We aim to obtain accurate transition wavelengths, improved energy levels and HFS constants of Sc II. The latest results from work in progress will be presented.Reference[1] Hartman H, Gull T, Johansson S and Smith N 2004 Astron. Astrophys. 419 215[2] Smith N, Morse J A and Gull T R 2004 Astrophys. J. 605 405[3] Davidson K and Humphreys R M 1997 Annu. Rev. Astron. Astrophys. 35[4] Johansson S and Litzén U 1980 Phys. Scr. 22 49

Compact torus accelerator as a driver for ICF

International Nuclear Information System (INIS)

Tobin, M.T.; Meier, W.R.; Morse, E.C.

1986-01-01

The authors have carried out further investigations of the technical issues associated with using a compact torus (CT) accelerator as a driver for inertial confinement fusion (ICF). In a CT accelerator, a magnetically confined, torus-shaped plasma is compressed, accelerated, and focused by two concentric electrodes. After its initial formation, the torus shape is maintained for lifetimes exceeding 1 ms by inherent poloidal and toroidal currents. Hartman suggests acceleration and focusing of such a plasma ring will not cause dissolution within certain constraints. In this study, we evaluated a point design based on an available capacitor bank energy of 9.2 MJ. This accelerator, which was modeled by a zero-dimensional code, produces a xenon plasma ring with a 0.73-cm radius, a velocity of 4.14 x 10 9 cm/s, and a mass of 4.42 μg. The energy of the plasma ring as it leaves the accelerator is 3.8 MJ, or 41% of the capacitor bank energy. Our studies confirm the feasibility of producing a plasma ring with the characteristics required to induce fusion in an ICF target with a gain greater than 50. The low cost and high efficiency of the CT accelerator are particularly attractive. Uncertainties concerning propagation, accelerator lifetime, and power supply must be resolved to establish the viability of the accelerator as an ICF driver

Direct numerical simulation of MHD heat transfer in high Reynolds number turbulent channel flows for Prandtl number of 25

International Nuclear Information System (INIS)

Yamamoto, Yoshinobu; Kunugi, Tomoaki

2015-01-01

Graphical abstract: - Highlights: • For the first time, the MHD heat transfer DNS database corresponding to the typical nondimensional parameters of the fusion blanket design using molten salt, were established. • MHD heat transfer correlation was proposed and about 20% of the heat transfer degradation was evaluated under the design conditions. • The contribution of the turbulent diffusion to heat transfer is increased drastically with increasing Hartmann number. - Abstract: The high-Prandtl number passive scalar transport of the turbulent channel flow imposed a wall-normal magnetic field is investigated through the large-scale direct numerical simulation (DNS). All essential turbulence scales of velocities and temperature are resolved by using 2048 × 870 × 1024 computational grid points in stream, vertical, and spanwise directions. The heat transfer phenomena for a Prandtl number of 25 were observed under the following flow conditions: the bulk Reynolds number of 14,000 and Hartman number of up to 28. These values were equivalent to the typical nondimensional parameters of the fusion blanket design proposed by Wong et al. As a result, a high-accuracy DNS database for the verification of magnetohydrodynamic turbulent heat transfer models was established for the first time, and it was confirmed that the heat transfer correlation for a Prandtl number of 5.25 proposed by Yamamoto and Kunugi was applicable to the Prandtl number of 25 used in this study

Direct numerical simulation of MHD heat transfer in high Reynolds number turbulent channel flows for Prandtl number of 25

Energy Technology Data Exchange (ETDEWEB)

Yamamoto, Yoshinobu, E-mail: yamamotoy@yamanashi.ac.jp [Department of Mechanical Systems Engineering, University of Yamanashi, 4-3-11 Takeda, Kofu 400-8511 (Japan); Kunugi, Tomoaki [Department of Nuclear Engineering, Kyoto University Yoshida, Sakyo, Kyoto 606-8501 (Japan)

2015-01-15

Graphical abstract: - Highlights: • For the first time, the MHD heat transfer DNS database corresponding to the typical nondimensional parameters of the fusion blanket design using molten salt, were established. • MHD heat transfer correlation was proposed and about 20% of the heat transfer degradation was evaluated under the design conditions. • The contribution of the turbulent diffusion to heat transfer is increased drastically with increasing Hartmann number. - Abstract: The high-Prandtl number passive scalar transport of the turbulent channel flow imposed a wall-normal magnetic field is investigated through the large-scale direct numerical simulation (DNS). All essential turbulence scales of velocities and temperature are resolved by using 2048 × 870 × 1024 computational grid points in stream, vertical, and spanwise directions. The heat transfer phenomena for a Prandtl number of 25 were observed under the following flow conditions: the bulk Reynolds number of 14,000 and Hartman number of up to 28. These values were equivalent to the typical nondimensional parameters of the fusion blanket design proposed by Wong et al. As a result, a high-accuracy DNS database for the verification of magnetohydrodynamic turbulent heat transfer models was established for the first time, and it was confirmed that the heat transfer correlation for a Prandtl number of 5.25 proposed by Yamamoto and Kunugi was applicable to the Prandtl number of 25 used in this study.

Synthetic alienation of microbial organisms by using genetic code engineering: Why and how?

Science.gov (United States)

Kubyshkin, Vladimir; Budisa, Nediljko

2017-08-01

The main goal of synthetic biology (SB) is the creation of biodiversity applicable for biotechnological needs, while xenobiology (XB) aims to expand the framework of natural chemistries with the non-natural building blocks in living cells to accomplish artificial biodiversity. Protein and proteome engineering, which overcome limitation of the canonical amino acid repertoire of 20 (+2) prescribed by the genetic code by using non-canonic amino acids (ncAAs), is one of the main focuses of XB research. Ideally, estranging the genetic code from its current form via systematic introduction of ncAAs should enable the development of bio-containment mechanisms in synthetic cells potentially endowing them with a "genetic firewall" i.e. orthogonality which prevents genetic information transfer to natural systems. Despite rapid progress over the past two decades, it is not yet possible to completely alienate an organism that would use and maintain different genetic code associations permanently. In order to engineer robust bio-contained life forms, the chemical logic behind the amino acid repertoire establishment should be considered. Starting from recent proposal of Hartman and Smith about the genetic code establishment in the RNA world, here the authors mapped possible biotechnological invasion points for engineering of bio-contained synthetic cells equipped with non-canonical functionalities. Copyright © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Pathway to a paradigm: the linear nonthreshold dose-response model in historical context. The American Academy of Health Physics 1995 Radiology Centennial Hartman Oration.

Science.gov (United States)

Kathren, R L

1996-05-01

This paper traces the evolution of the linear nonthreshold dose-response model and its acceptance as a paradigm in radiation protection practice and risk analysis. Deterministic effects such as skin burns and even deep tissue trauma were associated with excessive exposure to x rays shortly after their discovery, and carcinogenicity was observed as early as 1902. Still, it was not until 1925 that the first protective limits were suggested. For three decades these limits were based on the concept of a tolerance dose which, if not exceeded, would result in no demonstrable harm to the individual and implicitly assumed a threshold dose below which radiation effects would be absent. After World War II, largely because of genetic concerns related to atmospheric weapons testing, radiation protection dose limits were expressed in terms of a risk based maximum permissible dose which clearly implied no threshold. The 1927 discovery by Muller of x-ray induced genetic mutations in fruit flies, linear with dose and with no apparent threshold, was an important underpinning of the standards. The linear nonthreshold dose-response model was originally used to provide an upper limit estimate of the risk, with zero being the lower limit, of low level irradiation since the dose-response curve could not be determined at low dose levels. Evidence to the contrary such as hormesis and the classic studies of the radium dial painters notwithstanding, the linear nonthreshold model gained greater acceptance and in the centennial year of the discovery of x rays stands as a paradigm although serious questions are beginning to be raised regarding its general applicability. The work includes a brief digression describing the work of x-ray protection pioneer William Rollins and concludes with a recommendation for application of a de minimis dose level in radiation protection.

On the Hartman paradox, electromagnetic wave tunneling and supraluminal velocities (comment on the paper 'Tunneling of electromagnetic waves: paradoxes and prospects' by A B Shvartsburg)

International Nuclear Information System (INIS)

Davidovich, Mikhail V

2009-01-01

Some paradoxes are discussed concerning the interpretation of the passage of particles and electromagnetic waves (pulses) across potential barriers and through nonuniform media, in particular, those with frequency dispersion and therefore dissipation. It is emphasized that a rigorous nonstationary approach does not entail any supraluminal velocities for the transfer of physical substances, although supraluminal velocities are indeed possible for several kinematically defined velocities, e.g., for the group velocity. (letters to the editors)

MHD peristaltic transport of spherical and cylindrical magneto-nanoparticles suspended in water

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F. M. Abbasi

2015-07-01

Full Text Available Advancements in the biomedical engineering have enhanced the usage of magnto-nanoparticles in improving the precision and efficiency of the magneto-drug delivery systems. Such systems make use of the externally applied magnetic fields to direct the drug towards a specific target in the human body. Peristalsis of magneto-nanofluids is of significant importance in such considerations. Hence peristaltic transport of Fe3O4-water nanofluid through a two-dimensional symmetric channel is analyzed in the presence of an externally applied constant magnetic field. Hamilton-Crosser’s model of the thermal conductivity is utilized in the problem development. The nanofluid saturates a non-uniform porous medium in which the porosity of the porous medium varies with the distance from the channel walls. Analysis is performed for the spherical and the cylindrical nanoparticles. Resulting system of equations is numerically solved. Impacts of sundry parameters on the axial velocity, temperature, pressure gradient and heat transfer rate at the boundary are examined. Comparison between the results for spherical and cylindrical nanoparticles is also presented. Results show that the nanoparticles volume fraction and the Hartman number have increasing effect on the pressure gradient throughout the peristaltic tract. Effective heat transfer rate at the boundary tends to enhance with an increase in the nanoparticles volume fraction. Use of spherical nanoparticles results in a higher value of axial velocity and the temperature at the center of channel when compared with the case of cylindrical nanoparticles.

Influence of the esterification method on the quantification of olive oil fatty acids

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Maria Cristina Milinsk

2011-09-01

Full Text Available To analyze fatty acids by gas chromatography, it is necessary to apply esterification procedures to convert fatty acids into more volatile compounds, such as fatty acid methyl esters (FAME. Esterification methods are usually subdivided into two categories: acidic catalysis and basic catalysis. Due to the possibility of obtaining different concentrations of fatty acids for the same sample as a function of the esterification method used, the efficiency of eight different esterification methods that involve acidic and basic catalysis in the quantitative determination of FAME in olive oil was verified. The selected methods were described by Metcalfe, 1966 (MET; Bannon, 1982 (BAN; Joseph and Ackman, 1992 (JAC; Hartman and Lago, 1973 (HLA; Jham, 1982 (JHA; ISO 5509, 1978 (ISO; Bannon, 1982 (BBA and Schuchardt and Lopes, 1988 (SLO. The results showed the efficiency of the esterification methods for the main saturated fatty acids that were present in the olive oil analyzed. The most efficient methods for the esterification of unsaturated fatty acids in the oils analyzed were JAC, ISO, and BBA. Nevertheless, the reagent BF3 in methanol, used in the JAC method, is extremely toxic. Thus, when the oil to be analyzed has low acidity, the basic catalysis methods ISO and BBA can be used instead, since they use inexpensive reagents of low toxicity. The results obtained showed that the choice of a method for the analysis of fatty acids also depends on the composition of the oil to be studied.

Economic Impact of Net Carbon Payments and Bioenergy Production in Fertilized and Non-Fertilized Loblolly Pine Plantations

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Prativa Shrestha

2015-08-01

Full Text Available Sequestering carbon in forest stands and using woody bioenergy are two potential ways to utilize forests in mitigating emissions of greenhouse gases (GHGs. Such forestry related strategies are, however, greatly influenced by carbon and bioenergy markets. This study investigates the impact of both carbon and woody bioenergy markets on land expectation value (LEV and rotation age of loblolly pine (Pinus taeda L. forests in the southeastern United States for two scenarios—one with thinning and no fertilization and the other with thinning and fertilization. Economic analysis was conducted using a modified Hartman model. The amount of carbon dioxide (CO2 emitted during various activities such as management of stands, harvesting, and product decay was included in the model. Sensitivity analysis was conducted with a range of carbon offset, wood for bioenergy, and forest product prices. The results showed that LEV increased in both management scenarios as the price of carbon and wood for bioenergy increased. However, the results indicated that the management scenario without fertilizer was optimal at low carbon prices and the management scenario with fertilizer was optimal at higher carbon prices for medium and low forest product prices. Carbon payments had a greater impact on LEV than prices for wood utilized for bioenergy. Also, increase in the carbon price increased the optimal rotation age, whereas, wood prices for bioenergy had little impact. The management scenario without fertilizer was found to have longer optimal rotation ages.

Revision of Diplocirrus Haase, 1915, including Bradiella Rullier, 1965, and Diversibranchius Buzhinskaja, 1993 (Polychaeta, Flabelligeridae)

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Salazar-Vallejo, Sergio I.; Buzhinskaja, Galina

2011-01-01

Abstract Diplocirrus Haase, 1915, includes flabelligerids having cylindrical to club-shaped bodies, with cirriform papillae, multiarticulate chaetae in both parapodial rami, 8 branchial filaments of two types (thick and rarely lamellate, or cirriform), gonopodial lobes in chaetigers 5 or 6, or multiple gonopores along some anterior chaetigers. Bradiella Rullier, 1965, has included only the type species: Bradiella branchiata Rullier, 1965, described from Eastern Australia. The original description has been overlooked and it lacked enough details on branchial and chaetal features. Diversibranchius Buzhinskaja, 1993, with Diplocirrus nicolaji Buzhinskaja, 1994, as the type species, was introduced for a similar species from the Japan Sea. These two monotypic genera share the same morphologic features with Diplocirrus, and are herein regarded as its junior synonyms. As herein redefined, Diplocirrus includes, besides its type species, Diplocirrus glaucus (Malmgren, 1867)from Scandinavia : Diplocirrus branchiatus (Rullier, 1965), comb. n. from Queensland, Australia, Diplocirrus capensis Day, 1961 from South Africa, Diplocirrus erythroporus Gallardo, 1968 from Vietnam, Diplocirrus hirsutus (Hansen, 1882) from Arctic and subarctic regions, Diplocirrus incognitus Darbyshire & Mackie, 2009 from South Africa, Diplocirrus kudenovi sp. n. from off Western Mexico, Diplocirrus longisetosus (von Marenzeller, 1890) restricted to the Bering Sea, Diplocirrus micans Fauchald, 1972 from deep water off Oregon and Western Mexico, Diplocirrus nicolaji (Buzhinskaja, 1994), comb. n. from the Japan Sea, Diplocirrus normani (McIntosh, 1908), comb. n. from Scandinavia, Diplocirrus octobranchus (Hartman, 1965), comb. n. from off New England, and Diplocirrus stopbowitzi Darbyshire & Mackie, 2009 from the Irish Sea. PMID:21852920

Women's voices in English course-books in Italy: a diachronic survey from the 50s to the 80s

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Paola Vettorel

2014-03-01

Full Text Available Normal 0 14 false false false IT X-NONE X-NONE MicrosoftInternetExplorer4 Abstract English language teaching materials usually reflect both the explicit and the implicit attitudes and beliefs of their authors, of the society and the culture of the times they live in. Attitudes and beliefs are bound to change over time and are affected by socio-cultural changes, particularly in areas such as power relationships, the image of women and that of identity construction. The first coursebook analyses in terms of women’s representations and sexist attitudes date back to the 70s and the 80s (e.g. Hartman, Judd 1978; Stern 1976; Porreca 1984; Schmitz 1975, 1984 and have been greatly influenced by language and gender studies (e.g. Sunderland 1992, 1994, 2000; Sunderland, Litosseliti 2002; Cameron 2005. This paper is aimed at presenting the results of a study on how women and their voices have been portrayed in ELT coursebooks addressed to Italian students over time. The analysis carried out in a diachronic perspective, have specifically focussed upon textbooks published between the 1950s and the beginning of the 80s in order to represent different historical perspectives. The proposed stretch in time to the 80s is aimed at investigating the most relevant shifts occurring in ELT coursebooks in the 70s as a consequence of changes in society and the influence of gender studies. The categories used to analyse the ELT materials have been: the representation (as well as the omission of women and their roles in texts and illustrations; the language used to refer to women and its role in maintaining, diminishing or reinforcing sexist values. Despite a correspondence between gender representations and ongoing changes in society, the textbooks examined appear to represent more traditional than innovative views on women. Keywords: ELT course-books, women, attitudes, gender studies, diachronic study Abstract I materiali utilizzati per l’insegnamento dell�

Polychaetes (Annelida: Polychaeta described for the Mexican Pacific: an historical review and an updated checklist Los poliquetos (Annelida: Polychaeta descritos en el Pacífico mexicano: revisión histórica y lista faunística actualizada

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Pablo Hernández-Alcántara

2008-01-01

Full Text Available An updated checklist of the polychaete species described for the Mexican Pacific and an historic review of their study are presented. The taxonomic list includes nomenclature references, data of the type locality and synonyms based on systematic revisions. In the study area, 313 species of polychaetes and 21 genera have been described, of which 278 species are currently valid. Several descriptions (28% of the valid species failed to indicate the habitat of the type locality. The remaining 199 valid species were described for a large variety of habitats: algae (11 species, mangroves (2, hard bottoms (22, soft bottoms (continental shelf = 65 species; deep sea = 78 species, hydrothermal vents (17, and others (parasites, larval planktonic forms, epitokes (4. The species descriptions for the Mexican Pacific can be divided into four main periods: the first, during the 1910s, includes mainly Chamberlin's studies of deep sea fauna. The second, in the 1940s, comprises studies carried out by Rioja (intertidal zone and Hartman (including specimens from the Allan Hancock Foundation collection. The third period began around the 1970s when Fauchald's studies were published and 77 currently valid species were described for western Mexico. The fourth period began in the 1980s and continues to date, being characterized by descriptions of species done mainly by Mexican scientists. The differences in the number of species described during each period and for the different regions of the Mexican Pacific are directly related to the sampling effort carried out along these coasts.Se presenta una lista taxonómica de las especies de poliquetos descritos en el Pacífico mexicano y una revisión histórica de su estudio. El listado incluye referencias nomenclaturales, información sobre la localidad tipo y sinonimias basadas en revisiones sistemáticas. Un total de 313 especies y 21 géneros han sido descritos en el área de estudio, de ellas, 278 especies son

Last results of MADRAS, a space active optics demonstrator

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Laslandes, Marie; Hourtoule, Claire; Hugot, Emmanuel; Ferrari, Marc; Devilliers, Christophe; Liotard, Arnaud; Lopez, Céline; Chazallet, Frédéric

2017-11-01

The goal of the MADRAS project (Mirror Active, Deformable and Regulated for Applications in Space) is to highlight the interest of Active Optics for the next generation of space telescope and instrumentation. Wave-front errors in future space telescopes will mainly come from thermal dilatation and zero gravity, inducing large lightweight primary mirrors deformation. To compensate for these effects, a 24 actuators, 100 mm diameter deformable mirror has been designed to be inserted in a pupil relay. Within the project, such a system has been optimized, integrated and experimentally characterized. The system is designed considering wave-front errors expected in 3m-class primary mirrors, and taking into account space constraints such as compactness, low weight, low power consumption and mechanical strength. Finite Element Analysis allowed an optimization of the system in order to reach a precision of correction better than 10 nm rms. A dedicated test-bed has been designed to fully characterize the integrated mirror performance in representative conditions. The test set up is made of three main parts: a telescope aberrations generator, a correction loop with the MADRAS mirror and a Shack-Hartman wave-front sensor, and PSF imaging. In addition, Fizeau interferometry monitors the optical surface shape. We have developed and characterized an active optics system with a limited number of actuators and a design fitting space requirements. All the conducted tests tend to demonstrate the efficiency of such a system for a real-time, in situ wave-front. It would allow a significant improvement for future space telescopes optical performance while relaxing the specifications on the others components.

The relationship of psychosocial factors to mammograms, physical activity, and fruit and vegetable consumption among sisters of breast cancer patients

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Hartman SJ

2011-08-01

Full Text Available Sheri J Hartman1, Shira I Dunsiger1, Paul B Jacobsen21Centers for Behavioral and Preventive Medicine, The Miriam Hospital and W Alpert Medical School of Brown University, Providence, RI; 2Department of Health Outcomes and Behavior, H Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USAAbstract: This study examined the relationship of psychosocial factors to health-promoting behaviors in sisters of breast cancer patients. One hundred and twenty sisters of breast cancer patients completed questionnaires assessing response efficacy of mammography screenings, physical activity, and fruit and vegetable consumption on decreasing breast cancer risk, breast cancer worry, involvement in their sister’s cancer care, mammography screenings, physical activity, and fruit and vegetable consumption. Results indicate that greater perceived effectiveness for mammograms was associated with a 67% increase in odds of yearly mammograms. Greater involvement in the patient’s care was associated with a 7% decrease in odds of yearly mammograms. Greater perceived effectiveness for physical activity was significantly related to greater physical activity. There was a trend for greater perceived effectiveness for fruits and vegetables to be associated with consuming more fruits and vegetables. Breast cancer worry was not significantly associated with the outcomes. While perceived effectiveness for a specific health behavior in reducing breast cancer risk was consistently related to engaging in that health behavior, women reported significantly lower perceived effectiveness for physical activity and fruits and vegetables than for mammograms. Making women aware of the health benefits of these behaviors may be important in promoting changes.Keywords: breast cancer risk, mammograms, physical activity, diet, perceived effectiveness

Quality of life in patients with a permanent stoma after rectal cancer surgery.

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Näsvall, Pia; Dahlstrand, Ursula; Löwenmark, Thyra; Rutegård, Jörgen; Gunnarsson, Ulf; Strigård, Karin

2017-01-01

Health-related quality of life (HRQoL) assessment is important in understanding the patient's perspective and for decision-making in health care. HRQoL is often impaired in patients with stoma. The aim was to evaluate HRQoL in rectal cancer patients with permanent stoma compared to patients without stoma. 711 patients operated for rectal cancer with abdomino-perineal resection or Hartman's procedure and a control group (n = 275) operated with anterior resection were eligible. Four QoL questionnaires were sent by mail. Comparisons of mean values between groups were made by Student´s independent t test. Comparison was made to a Swedish background population. 336 patients with a stoma and 117 without stoma replied (453/986; 46 %). A bulging or a hernia around the stoma was present in 31.5 %. Operation due to parastomal hernia had been performed in 11.7 % in the stoma group. Mental health (p = 0.007), body image (p stoma. Fatigue (p = 0.019) and loss of appetite (p = 0.027) were also more prominent in the stoma group. Sexual function was impaired in the non-stoma group (p = 0.034). However in the stoma group, patients with a bulge/hernia had more sexual problems (p = 0.004). Pain was associated with bulge/hernia (p stoma was inferior compared to patients without stoma. In the stoma group, a bulge or a hernia around the stoma further impaired HRQoL.

Editors' Note

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Ellen R. Cohn

2015-11-01

Full Text Available The Fall 2015 issue of the International Journal of Telerehabilitation (IJT presents the original work of three distinguished and innovative interdisciplinary teams.  Interdisciplinarity is also a hallmark of the IJT editorial staff, reviewers, and publishing team.The first article is a product of engineers with expertise in computing science (LoPresti and Simpson and a medical speech-language pathologist (Jinks who practices in the area of assistive technology. These authors reported upon the degree to which consumers are satisfied with the provision of telerehabilitation services for augmentative and alternative communication or alternative computer accessibility.A second article, by Proffitt, (occupational therapist and Lange, (a physiotherapist with expertise in the use of interactive video games and virtual reality technologies demonstrated the feasibility of employing a 6-week, game-based, in-home telerehabilitation exercise program using the Microsoft Kinect® for individuals with chronic stroke.Finally, the third article co-authored by Watzlaf (health information management, with degrees in public health and epidemiology, DeAlmeida (health information systems, with a degree in cell and molecular biology, Zhou (with degrees in computer science and physics, and expertise in mathematical modeling on health related topics, information integration, and comparative genomics, and Hartman (a reference librarian with a degree in chemistry, who collaborates with faculty in the health sciences and serves as a liaison to a school of health and rehabilitation sciences describes a protocol to conduct systematic reviews of research in telerehabilitation, with the aim that IJT readers can ultimately apply this protocol to identify best practices in telerehabilitation.

Variability in the quality of rectal cancer care in public hospitals in Catalonia (Spain): clinical audit as a basis for action.

Science.gov (United States)

Manchon-Walsh, P; Borras, J M; Espinas, J A; Aliste, L

2011-04-01

Clinical practice guidelines in cancer are a relevant component of Catalonian Cancer Strategy aimed at promoting equity of access to therapy and quality of cancer care. The colorectal cancer (CRC) guideline was first published in 2003 and subsequently updated in 2008. This study examined the quality of therapy administered to patients with rectal cancer in public hospitals in Catalonia (Spain) in 2005 and 2007, according to CRC guideline recommendations. We conducted a multicentre retrospective cohort study of patients who underwent curative-intent surgery for primary rectal cancer at Catalonian public hospitals in 2005 and 2007. Data were drawn from clinical records. The study covered 1831 patients with rectal cancer. Performance of total mesorectal excision (TME) was poorly reported by surgeons (46.4%) and pathologists (36.2%). Pre-operative radiotherapy was performed on 52% of stage-II and -III patients. Compared to high-caseload hospitals, those with a low caseload (≤11 cases/year) registered more Hartman's procedures, worse TME quality, a higher rate of post-operative complications and lower adherence to recommended pre-operative radio-chemotherapy. Reporting quality of care is essential for ascertaining current performance status and opportunities for improvement. In our case, there is a need for the quality of the information included in clinical records to be improved, and variability in adherence to guideline recommendations to be reduced. In view of the fact that heterogeneity in the quality of the health care process was linked to hospital caseload, the health authorities have decided to reorganise the provision of rectal cancer care. Copyright © 2011 Elsevier Ltd. All rights reserved.

MHD mixed convection flow and heat transfer in an open C-shaped enclosure using water-copper oxide nanofluid

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Armaghani, T.; Esmaeili, H.; Mohammadpoor, Y. A.; Pop, I.

2018-01-01

In this paper, the steady mixed convection flow and heat transfer of water-copper oxide nanofluid in an open C-shaped enclosure is investigated numerically. The enclosure is under constant magnetic field. Effects of Richardson number, magnetic and nanofluid volume fraction parameters are studied and discussed. The nanofluid with a cold temperature of T C and a velocity of u c enters the enclosure from the top right corner and exits from the bottom right corner. The vertical wall of the left side is subjected to a hot and constant temperature T h . Also, other walls are insulated. It is found that the heat transfer is increased via increasing the Hartmann and Reynolds numbers. For low Reynolds numbers, the enhances of the Hartman number leads to a slightly increases of the average Nusselt number, but for high Reynolds numbers, the average Nusselt number gets an ascending trend and the increase in the Hartmann number shows its effect more pronounced. Also, with increase in Ri, the effect of nanofluid on the heat transfer increases. Due to practical impotence, the study of mixed convection heat transfer in enclosures and various shaped of cavities has attracted remarkable attentions in the past few decades. Significant applications of the mixed convection flow can be found in atmospheric flows, solar energy storage, heat exchangers, lubrication technology, drying technologies, cooling of the electronic devices, etc. The present results are original and new for the problem of MHD mixed convection flow and heat transfer in an open C-shaped enclosure using water-copper oxide nanofluid. Comparison of the obtained results with those from the open literature (Mahmoodi et al. [24]) is acceptable.

Morphological variations caused by fixation techniques may lead to taxonomic confusion in Laeonereis (Polychaeta: Nereididae

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Verônica M. Oliveira

2010-02-01

Full Text Available The nereidid polychaete Laeonereis acuta (Treadwell, 1923 is either considered to be a valid species, or a synonym of Laeonereis culveri (Webster, 1879. The species epithet, acuta, refers to the acuminate anterior region of the body followed by a widening that is visible up to the 10th setiger. The relative width of the anterior region of the body, however, has been reported in the taxonomic literature as variable for Laeonereis Hartman, 1945, a genus known from the eastern coast of North America to Patagonia (southern South America. To test whether variations in this character are real, or whether they correspond to an artifact, we analyzed morphological changes associated with different anesthesia and fixation techniques regularly used to prepare specimens of Laeonereis from southern Brazil (formerly reported as L. acuta. Six treatments, including combinations of anesthetics and fixative agents, and a control, were evaluated in groups of 25 adult animals. A simple model II regression analysis on living specimens showed that the growth is approximately isometric. One-way ANOVA was used to compare the treatment effect on the ratio of peristome width: setiger 6 width. This ratio was smaller in non-anesthetized individuals, especially when prepared in formalin and freshwater. When anesthetized with menthol and fixed in formalin with sea water, individuals retained a shape that was closest to their in vivo shape. Consequently, our results suggest that fixation without prior anesthesia is not recommended for morphological and taxonomical studies. Since morphology and morphometrics of the anterior region are consistently influenced by preparation techniques, it is likely that inadequate fixation routines have introduced several errors in the taxonomic and ecological literature of Laeonereis.

Types and Indications of Colostomy and Determinants of Outcomes of Patients After Surgery.

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Engida, Abebe; Ayelign, Tsehay; Mahteme, Bekele; Aida, Tilahun; Abreham, Berhane

2016-03-01

Colostomy is one of the commonest life saving procedures done worldwide with an intention of either decompression of an obstructed colon or diversion of stool. Indications may vary from region to region. Attending morbidity and mortality is significant. the objective of this study was to Determine the common indications and types of colostomy, and outcomes of patients operated at SPHMMC. A retrospective medical records of patients, operation log book and nursing records review was done in a two-year period between January 2011 and December 2013 at the College Teaching Hospital, St Paul's Hospital Millennium Medical, Addis Ababa. During the two years, 253 colostomies were done and 219(86.6%) cases used for analysis. Of these, 151(68.9%) were males. Age ranged from 15 to 85 years with a mean of 50.8. Most of the surgeries, 196(89.5%), were done for emergency conditions. The three most common indications were gangrenous sigmoid volvulus, 102(46.6%), colorectal cancers, 46(21.0%, and abdominal injuries, 28(12.8%). The commonest type of colostomy done was Hartman's colostomy, 179(81.7.1%), gangrenous sigmoid volvulus being the predominant indication, 102(57%). Loop colostomy constituted 35(16%) of all the colostomies. Penetrating abdominal injuries was the main indication 15(42.9%). Overall, 157 complications were seen on 106(48.4%) patients. The most common complications were surgical site infection, 51(23.3%), hospital acquired pneumonia, (10.5%), and wound dehiscence, 17(7.8%). The mortality rate was 9.6% (21). Gangrenous sigmoid volvulus is the leading indication for colostomy. Mortality and morbidity rates are high. Aggressive resuscitation, early prompt operation and post op close follow-up should be emphasized.

Timing of the deposition of uppermost Cretaceous and Paleocene coal-bearing deposits in the Greater Glendive area, Montana and North Dakota

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-02-01

With the aid of a grant from the National Geographic Society, a cooperative agreement with the State University of New York at Stony Brook, and contract with the U.S. Department of Energy, Late Cretaceous and Paleocene geologic and paleontologic field studies were undertaken in Makoshika, State Park and vicinity, Dawson County, Montana. This region was chosen as a study area because of its potential for yielding new fossil localities and extensive exposures both above and below the K/T boundary, as suggested by previous research by David W. Krause and Joseph H. Hartman. Related field studies were also undertaken in areas adjacent to the Cedar Creek Anticline in North Dakota. This work was part of ongoing research to document change in the composition of mammalian and molluscan faunas during the Late Cretaceous and Paleocene and to relate observed patterns to floral and invertebrate changes in composition. This study focuses on the record of mammals and mollusks in the Makoshika stratigraphic section and places old and new observations into a paleomagnetic and palynomorph framework. Of particular interest is the appearance and diversification of archaic ungulate mammals. Simultaneous dinosaur extinction with ungulate radiation has been invoked in gradual, as opposed to catastrophic, models of faunal change at the K/T boundary. However, supposed Cretaceous localities bearing archaic ungulates and other mammals of {open_quotes}Paleocene aspect{close_quotes} may be the product of faunal reworking. Elsewhere in the Williston Basin (e.g., Garfield and McCone Counties, Montana), the molluscan record of uppermost Cretaceous and Paleocene strata indicates the extinction of all of the highly sculptured unionid bivalves just prior to the onset of coal swamps and subsequent coal formation.

Hearing and sports: a bidirectional interaction. [Audición y Control motor: Una relación recíproca].

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Johannes Vogel

2014-10-01

Full Text Available Introduction Motor control is crucially dependent on many sensory inputs that involve classically the proprioreceptors located in the tendons, joints and the muscle itself as well as inputs from the vestibular organ and eyes (Fitzpatrick and McCloskey, 1994. However, additional sensory input from the auditory system is often necessary to perform the sport-associated complex motor-tasks. This holds not only for team sports that requires continuous communication with the other players but also for others such as figure skating or gymnastics where the movements of the body need to be coordinated with music. In addition, hearing is also important for avoiding accidents e.g. during skiing to recognize other people on the same track. Conversely, specific sports wear used in these sports may negatively influence hearing as it was shown for ski helmets that reduce perception of safety-relevant frequencies (Ruedl, Kopp, Burtscher, Zorowka, Weichbold, Stephan, Koci and Seebacher, 2014; Tudor, Ruzic, Bencic, Sestan and Bonifacic, 2010. Moreover, the reaction time and force generated during voluntary contractions could be influenced by sound. For instance, runners closer to the starter's pistol at Olympic Games react sooner than runners farther away (Brown, Kenwell, Maraj and Collins, 2008. Finally, hearing could even influence the overall physical fitness as it might be reduced in deaf children (Hartman, Visscher and Houwen, 2007 although other studies could not confirm (Wierzbicka-Damska, Samolyk, Jethon, Wiercinska and Murawska-Cialowicz, 2005. In the elderly, sensory deficits such as poor vision and hearing may increase the risk of mobility decline (Viljanen, Kaprio, Pyykko, Sorri, Koskenvuo and Rantanen, 2009a; Viljanen, Kaprio, Pyykko, Sorri, Pajala, Kauppinen, Koskenvuo and Rantanen, 2009b.

The troglomorphic adaptations of Namanereidinae (Annelida, Nereididae revisited, including a redescription of Namanereis cavernicola (Solís-Weiss & Espinasa, 1991, and a new Caribbean species of Namanereis Chamberlin, 1919

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Víctor Manuel Conde-Vela

2017-09-01

Full Text Available Most species belonging to Namanereis Chamberlin, 1919 live in freshwater and subterranean waters, even in water bodies several meters above sea level. A new species belonging to the stygobiont Namanereis group is described here; it shares the common morphological characters of absence of eyes and pigmentation, bifid jaws, elongation of chaetae and cirri, which have been recently regarded as troglomorphies. Because these features are used in evaluations of phylogenetic affinity in Namanereis, a review of these features was made for all known namanereidins, and it was extended to include species in Namalycastis Hartman, 1959. It is shown that elongation of tentacular and dorsal cirri, or elongation of upper sub-acicular falcigers in pre- or post-acicular fascicles, are not exclusive or restricted to species living in subterranean habitats or to Namanereis, because these features are also present in several Namalycastis species. However, the presence of bifid jaws, and the absence of eyes are exclusively found in namanereidins living in subterranean habitats. A hypothetical evolutionary derivation of bifid jaws is proposed, based upon observations of jaw morphology of several species. These exclusive troglomorphic characters (bifid jaws, eyeless are regarded as convergent features to aphotic environments, and they should be discouraged as indicators of common ancestry. The new species, herein described as Namanereis christopheri sp. n., was collected in a cave 435 m above sea level in Saint Vincent, Caribbean Sea. The species resembles N. cavernicola but it differs because it has shorter tentacular cirri, margin of prostomium entire, rounded neuropodial lobes and broader dorsal cirri throughout body. A key to identify all known Namanereis species is included.

Single center experience in laparoscopic treatment of gallbladder perforation.

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Sahbaz, Nuri Alper; Peker, Kivanc Derya; Kabuli, Hamit Ahmet; Gumusoglu, Alpen Yahya; Alis, Halil

2017-12-01

Gallbladder perforation (GBP) is a rare disease with potential mortality. Previous series have reported an incidence of approximately 2-11% and it still continues to be a significant problem for surgeons. To present our clinical experience with gallbladder perforation. The records of 2754 patients who received surgical treatment for cholelithiasis between 2010 and 2016 were reviewed retrospectively. One hundred thirty-three patients had gallbladder perforation. Age, gender, time from the onset of symptoms, diagnostic procedures, surgical treatment, morbidity and mortality rates were evaluated. 15.78% of patients had a body mass index > 35. 6.76% had chronic obstructive pulmonary disease, 6.76% had cardiac disease, 10.52% had diabetes and 4.51% had sepsis. American Society of Anesthesiology scores were I in 54.13%, II in 35.33%, III in 6.01% and IV in 4.51% of the patients. 27.81% of patients were diagnosed during surgery. The perforation site was the gallbladder fundus in 69.17%, body in 17.30%, Hartman's pouch in 10.53% and cystic duct in 3% of patients. Treatment modalities were laparoscopic cholecystectomy in 82.71%, open cholecystectomy in 3%, percutaneous drainage catheters + laparoscopic cholecystectomy in 3%, laparoscopic cholecystectomy + fistula repair in 10.53% and open cholecystectomy + fistula repair in 0.75% of patients. Mean length of hospital stay was 1.69 days. Mortality and morbidity rates were 8.27% and 10.52%, respectively. Histopathology results were acute cholecystitis in 69.93%, chronic cholecystitis in 20.30% and acute exacerbation over chronic cholecystitis in 9.77% of patients. Appropriate classification and management of perforated cholecystitis is essential. Laparoscopic cholecystectomy is a safe and feasible method to decrease morbidity in gallbladder perforations.

Morphological distinction between estuarine polychaetes: Laeonereis culveri and L. nota (Phyllodocida: Nereididae).

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de Jesus-Flores, Citlalli; Salazar-González, S Alejandro; Salazar-Vallejo, Sergio I

2016-03-01

The family Nereididae includes more than 500 polychaete species described worldwide, and includes species common in many benthic environments, but some other species may tolerate freshwater or can even thrive in humid substrates in tropical forests. In estuarine environments, nereidid polychaetes can be abundant and relevant as a food source for resident or migratory birds. Laeonereis culveri (Webster, 1879) is a common estuarine species found in tropical and subtropical Atlantic American shores and was described from New Jersey; its median and posterior parapodia have upper notopodial ligules usually longer than the lower ones, and the latter are parallel to the notaciculae throughout the body. L. culveri distribution is from Connecticut to central Argentina; however, this wide distribution might be due to the inclusion of several other species as junior synonyms, despite that some morphological differences were found between them. One of such species is L. nota (Treadwell, 1941), that was described from Texas; its parapodia have notopodial ligules of about the same size, and the lower ones are oblique to the notaciculae. In order to clarify the differences between these two species, and to define which inhabits the Northwestern Caribbean region, topotype materials from these two species and specimens from Chetumal Bay were collected, and their morphological features were compared. Our results indicated that L. culveri and L. nota are different species and that the latter is found in Chetumal Bay. On the basis of mature specimens, L. culveri is hereby restricted to the Northern Gulf of Mexico and Northwestern Atlantic Ocean, and L. nota are reinstated and its distribution extends from Texas, in the Gulf of Mexico to Chetumal Bay, in the Northwestern Caribbean Sea. A key to identify all species in Laeonereis Hartman (1945) is also included.

Wave aberrations in rhesus monkeys with vision-induced ametropias

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Ramamirtham, Ramkumar; Kee, Chea-su; Hung, Li-Fang; Qiao-Grider, Ying; Huang, Juan; Roorda, Austin; Smith, Earl L.

2007-01-01

The purpose of this study was to investigate the relationship between refractive errors and high-order aberrations in infant rhesus monkeys. Specifically, we compared the monochromatic wave aberrations measured with a Shack-Hartman wavefront sensor between normal monkeys and monkeys with vision-induced refractive errors. Shortly after birth, both normal monkeys and treated monkeys reared with optically induced defocus or form deprivation showed a decrease in the magnitude of high-order aberrations with age. However, the decrease in aberrations was typically smaller in the treated animals. Thus, at the end of the lens-rearing period, higher than normal amounts of aberrations were observed in treated eyes, both hyperopic and myopic eyes and treated eyes that developed astigmatism, but not spherical ametropias. The total RMS wavefront error increased with the degree of spherical refractive error, but was not correlated with the degree of astigmatism. Both myopic and hyperopic treated eyes showed elevated amounts of coma and trefoil and the degree of trefoil increased with the degree of spherical ametropia. Myopic eyes also exhibited a much higher prevalence of positive spherical aberration than normal or treated hyperopic eyes. Following the onset of unrestricted vision, the amount of high-order aberrations decreased in the treated monkeys that also recovered from the experimentally induced refractive errors. Our results demonstrate that high-order aberrations are influenced by visual experience in young primates and that the increase in high-order aberrations in our treated monkeys appears to be an optical byproduct of the vision-induced alterations in ocular growth that underlie changes in refractive error. The results from our study suggest that the higher amounts of wave aberrations observed in ametropic humans are likely to be a consequence, rather than a cause, of abnormal refractive development. PMID:17825347

Superluminal and negative delay times in isotropic-anisotropic one-dimensional photonic crystal

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Ouchani, N.; El Moussaouy, A.; Aynaou, H.; El Hassouani, Y.; El Boudouti, E. H.; Djafari-Rouhani, B.

2017-11-01

In this work, we investigate the possibility of superluminal and negative delay times for electromagnetic wave propagation in a linear and passive periodic structure consisting of alternating isotropic and anisotropic media. This phenomenon is due to the birefringence of the anisotropic layers of the structure. By adjusting the orientations of these layers, the delay times of transmitted waves can be controlled from subluminality to superluminality and vice versa. Numerical results indicate that the apparent superluminal propagation of light occurs inside the photonic band-gaps when the principal axes of the anisotropic layers are parallel or perpendicular to the fixed axes. For other orientations of these layers, tunneling and superluminal regimes appear inside the photonic bandgaps and in the allowed bands for frequencies close to the transmission minima. The effect of the number of unit cells of the photonic crystal structure on the propagation of light with superluminal and negative delay times is also investigated. We show that the structure exhibits the Hartman effect in which the tunneling delay time of the electromagnetic wave through the photonic band-gap of the structure converges asymptotically to a finite value with increasing the number of layers. The Green's function approach has been used to derive the transmission and reflection coefficients, the density of states, and the delay times of electromagnetic waves propagating through the structure. The control of the magnitude and the sign of the delay time of light propagation represent a key point in slow and fast light technologies. The proposed structure in this study represents a new system for controlling the delay times of wave propagation without a need of active or non-linear media as well as lossy or asymmetric periodic structures.

Bioaccumulation of Aluminium in Hydromacrophytes in Polish Coastal Lakes

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Senze Magdalena

2015-03-01

Full Text Available The research on aluminium content was conducted in water and on aquatic flora of Polish lakes in the central part of the coast. The study included the lakes Sarbsko, Choczewskie, Bia.e, K.odno, D.brze and Salino investigated in the summer of 2013. The examined lakes belong mainly to the direct basin of the Baltic Sea. Samples of aquatic plants and lake waters were collected. In the water samples pH and electrolytic conductivity were measured. The aluminium content was determined both in water and aquatic plants. Submerged hydromacrophyte studies included Myriophyllum alterniflorum L., Potamogeton perfoliatus L. and Ceratophyllum demersum L. Emergent hydromacrophyte studies included Phragmites australis (Cav. Trin. ex Steud., Juncus bulbosus L., Iris pseudacorus L., Eleocharis palustris (L. Roem. % Schult., Phalaris arundinacea L., Carex riparia Curt., Mentha aquatic L., Stratiotes aloides L., Alisma plantago-aquatica L., Glyceria maxima (Hartman Holmb., Sagittaria sagittifolia L., Scirpus lacustris L. and Typha angustifolia L. The purpose of this investigation was the determination of the aluminium content in submerged and emergent hydromacrophytes and also the definition of their bioaccumulative abilities. The average concentration of aluminium in water was 2.68 fęg Al dm.3. The average content of aluminium in plants was 2.8015 mg Al kg.1. The bioaccumulation factor ranged from BCF=19.74 to BCF=16619. On the basis of the analysis of the aluminium content in water and aquatic plants results show that both water and plants were characterized by a moderate level of aluminium. The recorded concentrations indicate a mid-range value and are much lower than those which are quoted for a variety of surface waters in various parts of the world.

Synchroton Radiation Sources

International Nuclear Information System (INIS)

Hulbert, S.L.; Williams, G.P.

1998-01-01

Synchrotron radiation is a very bright, broadband, polarized, pulsed source of light extending from the infrared to the x-ray region. It is an extremely important source of Vacuum Ultraviolet radiation. Brightness is defined as flux per unit area per unit solid angle and is normally a more important quantity than flux alone particularly in throughput limited applications which include those in which monochromators are used. It is well known from classical theory of electricity and magnetism that accelerating charges emit electromagnetic radiation. In the case of synchrotron radiation, relativistic electrons are accelerated in a circular orbit and emit electromagnetic radiation in a broad spectral range. The visible portion of this spectrum was first observed on April 24, 1947 at General Electric's Schenectady facility by Floyd Haber, a machinist working with the synchrotron team, although the first theoretical predictions were by Lienard in the latter part of the 1800's. An excellent early history with references was presented by Blewett and a history covering the development of the utilization of synchrotron radiation was presented by Hartman. Synchrotron radiation covers the entire electromagnetic spectrum from the infrared region through the visible, ultraviolet, and into the x-ray region up to energies of many 10's of kilovolts. If the charged particles are of low mass, such as electrons, and if they are traveling relativistically, the emitted radiation is very intense and highly collimated, with opening angles of the order of 1 milliradian. In electron storage rings there are three possible sources of synchrotron radiation; dipole (bending) magnets; wigglers, which act like a sequence of bending magnets with alternating polarities; and undulators, which are also multi-period alternating magnet systems but in which the beam deflections are small resulting in coherent interference of the emitted light

Hydrogen adsorption strength and sites in the metal organic framework MOF5: Comparing experiment and model calculations

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Mulder, F. M.; Dingemans, T. J.; Schimmel, H. G.; Ramirez-Cuesta, A. J.; Kearley, G. J.

2008-07-01

Hydrogen adsorption in porous, high surface area, and stable metal organic frameworks (MOF's) appears a novel route towards hydrogen storage materials [N.L. Rosi, J. Eckert, M. Eddaoudi, D.T. Vodak, J. Kim, M. O'Keeffe, O.M. Yaghi, Science 300 (2003) 1127; J.L.C. Rowsell, A.R. Millward, K. Sung Park, O.M. Yaghi, J. Am. Chem. Soc. 126 (2004) 5666; G. Ferey, M. Latroche, C. Serre, F. Millange, T. Loiseau, A. Percheron-Guegan, Chem. Commun. (2003) 2976; T. Loiseau, C. Serre, C. Huguenard, G. Fink, F. Taulelle, M. Henry, T. Bataille, G. Férey, Chem. Eur. J. 10 (2004) 1373]. A prerequisite for such materials is sufficient adsorption interaction strength for hydrogen adsorbed on the adsorption sites of the material because this facilitates successful operation under moderate temperature and pressure conditions. Here we report detailed information on the geometry of the hydrogen adsorption sites, based on the analysis of inelastic neutron spectroscopy (INS). The adsorption energies for the metal organic framework MOF5 equal about 800 K for part of the different sites, which is significantly higher than for nanoporous carbon materials (˜550 K) [H.G. Schimmel, G.J. Kearley, M.G. Nijkamp, C.T. Visser, K.P. de Jong, F.M. Mulder, Chem. Eur. J. 9 (2003) 4764], and is in agreement with what is found in first principles calculations [T. Sagara, J. Klassen, E. Ganz, J. Chem. Phys. 121 (2004) 12543; F.M. Mulder, T.J. Dingemans, M. Wagemaker, G.J. Kearley, Chem. Phys. 317 (2005) 113]. Assignments of the INS spectra is realized using comparison with independently published model calculations [F.M. Mulder, T.J. Dingemans, M. Wagemaker, G.J. Kearley, Chem. Phys. 317 (2005) 113] and structural data [T. Yildirim, M.R. Hartman, Phys. Rev. Lett. 95 (2005) 215504].

Chirality Switching by Martensitic Transformation in Protein Cylindrical Crystals: Application to Bacterial Flagella

Science.gov (United States)

Komai, Ricardo Kiyohiro

Martensitic transformations provide unique engineering properties that, when designed properly, become important parts of new technology. Martensitic transformations have been studied for many years in traditional alloys (iron, steel, titanium, etc.), however there is still much to be learned in regards to these transformations in biological materials. Olson and Hartman showed in 1982 that these transformations are also observed in bacterial flagella and T4 bacteriophage viral sheaths, allowing for propulsion of bacteria in a fluid environment and, for the virus, is responsible for the infection mechanism. This work demonstrates, using the bacterial flagella as an example, that these transformations can be modelled using thermodynamic methods that are also used to model the transformations in alloys. This thesis work attempts to explain the transformations that occur in bacterial flagella, which are capable of small strain, highly reversible martensitic transformations. The first stress/temperature phase diagrams of these flagella were created by adding the mechanical energy of the transformation of the flagella to limited chemical thermodynamics information of the transformation. Mechanical energy is critical to the transformation process because the bacterial body applies a torque to the radius of the flagella. Finally, work has begun and will be completed in regards to understanding the kinetics of the transformation of the flagella. The motion of the transformation interface can be predicted by using a Landau-Ginzburg model. The crystallography of the transformation in bacterial flagella is also being computed to determine the invariant lines of transformation that occur within this cylindrical crystal. This work has shown that it is possible to treat proteins in a similar manner that alloys are treated when using thermodynamic modelling. Much can be learned from translating what is known regarding phase transformations in hard material systems to soft, organic

The approach of ischemic colitis case followed by the lower gastrointesitnal bleeding

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YUKSEL ALTINEL

2017-03-01

Full Text Available Colonic vascular ischemia is commonly seen in the descending colon and causes malnutrition and is to be commensurate with the duration of clinical myocardial ischemia. History of cerebrovascular disease, hypertension, with coronary hearth disease, 68-year-old female patient was followed for about 2 weeks with the occasional massive gastrointestinal bleeding complaint. After ceasing oral intake, fluid and electrolyte replacement and a broad-spectrum antibiotic therapy was established. Abdomen bowel wall thickening of the colon in continuity in the CT results were observed with the open SMA SMV. Follow-up colonoscopy was performed from the dentate line at 5 cm starting hemorrhagic and ischemic segments was seen as an area of ​​about 40 cm long. After hemodynamic deterioration she was underwent emergency surgery because of abdominal sensitivity increase. Hartman procedure was performed. Postop pneumonia and pulmonary embolism were suspected. Candida was observed in urine infection. The sudden improving of the patient's postoperative bleeding from the rectal stump where the staple line was, has evolved on the 7th day. The sponges with the adrenaline stopped the bleeding and the hemodynamic support was stabilized with it. The minimal fluid in pelvis was also monitored by ultrasound . The colostomy was fine following the blood supply to the bowel. Later oral intake was started, the general condition of the patient was improved. But on the postoperative day 12 she had suddenly respiratory and cardiac arrest . Finally, the histopathological examination revealed that the ischemic necrosis and purulent some areas could be selected as a morphologic ischemic and necrotic (the intraoperative peritoneal reflection of the level of false membrane formation at the perforation focus off ischemic colitis. Approximately 20% of similar cases were followed with the clinical practice under medical treatment and surgical approach. [J Contemp Med 2017; 7(1.000: 74-76

Intrarectal negative pressure system in the management of open abdomen with colorectal fistula: A case report☆

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Yetişir, Fahri; Salman, A. Ebru; Mamedov, Ruslan; Aksoy, Mustafa; Yalcin, Abdussamet; Kayaalp, Cüneyt

2014-01-01

INTRODUCTION To present the management of open abdomen with colorectal fistula by application of intrarectal negative pressure system (NPS) in addition to abdominal NPS. PRESENTATION OF CASE Twenty-year old man had a history of injuries by a close-range gunshot to the abdomen eight days ago and he had been treated by bowel repairs, resections, jejunal anastomosis and Hartman's procedure. He was referred to our center after deterioration, evisceration with open abdomen and enteric fistula in septic shock. There were edematous, fibrinous bowels and large multiple fistulas from the edematous rectal stump. APACHE II, Mannheim Peritoneal Index and Björck scores were 18, 33 and 3, respectively (expected mortality 100%). After intensive care for 5 days, he was treated by abdominal and intrarectal NPS. NPS repeated for 5 times and the fistula was recovered on day 18 completely. Fascial closure was facilitated with a dynamic abdominal closure system (ABRA) and he was discharged on day 33 uneventfully. There was no herniation and any other problem after 12 months follow-up. DISCUSSION Management of fistula in OA can be extremely challenging. Floating stoma, fistula VAC, nipple VAC, ring and silo VAC, fistula intubation systems are used for isolation of the enteric effluent from OA. Several biologic dressings such as acellular dermal matrix, pedicled flaps have been used to seal the fistula opening with various success. Resection of the involved enteric loop and a new anastomosis of the intestine is very hard and rarely possible. In all of these reports, usually patients are left to heal with a giant hernia. In contrast to this, there is no hernia in our case during one year follow up period. CONCLUSION Combination of intra and extra luminal negative pressure systems and ABRA is a safe and successful method to manage open abdomen with colorectal fistula. PMID:24584042

Intrarectal negative pressure system in the management of open abdomen with colorectal fistula: A case report.

Science.gov (United States)

Yetişir, Fahri; Salman, A Ebru; Mamedov, Ruslan; Aksoy, Mustafa; Yalcin, Abdussamet; Kayaalp, Cüneyt

2014-01-01

To present the management of open abdomen with colorectal fistula by application of intrarectal negative pressure system (NPS) in addition to abdominal NPS. Twenty-year old man had a history of injuries by a close-range gunshot to the abdomen eight days ago and he had been treated by bowel repairs, resections, jejunal anastomosis and Hartman's procedure. He was referred to our center after deterioration, evisceration with open abdomen and enteric fistula in septic shock. There were edematous, fibrinous bowels and large multiple fistulas from the edematous rectal stump. APACHE II, Mannheim Peritoneal Index and Björck scores were 18, 33 and 3, respectively (expected mortality 100%). After intensive care for 5 days, he was treated by abdominal and intrarectal NPS. NPS repeated for 5 times and the fistula was recovered on day 18 completely. Fascial closure was facilitated with a dynamic abdominal closure system (ABRA) and he was discharged on day 33 uneventfully. There was no herniation and any other problem after 12 months follow-up. Management of fistula in OA can be extremely challenging. Floating stoma, fistula VAC, nipple VAC, ring and silo VAC, fistula intubation systems are used for isolation of the enteric effluent from OA. Several biologic dressings such as acellular dermal matrix, pedicled flaps have been used to seal the fistula opening with various success. Resection of the involved enteric loop and a new anastomosis of the intestine is very hard and rarely possible. In all of these reports, usually patients are left to heal with a giant hernia. In contrast to this, there is no hernia in our case during one year follow up period. Combination of intra and extra luminal negative pressure systems and ABRA is a safe and successful method to manage open abdomen with colorectal fistula. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

Numerically Simulated Impact of Gas Prandtl Number and Flow Model on Efficiency of the Machine-less Energetic Separation Device

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K. S. Egorov

2015-01-01

Full Text Available The presented paper regards the influence of one of similarity criteria – the Prandtl number of gas (Pr - on the efficiency of the machine-less energetic separation device (Leontiev pipe, using numerical modeling in ANSYS software. This device, equally as Rank-Hilsch and Hartman-Schprenger pipes, is designed to separate one gas flow into two flows with different temperatures. One flow (supersonic streams out of the pipe with a temperature higher than initial and the other (subsonic flows out with a temperature lower than initial. This direction of energetic separation is true if the Prandtl number is less than 1 that corresponds to gases.The Prandtl number affects the efficiency of running Leontiev pipe indirectly both through a temperature difference on which a temperature recovery factor has an impact and through a thermal conductivity coefficient that shows the impact of heat transfer intensity between gas and solid wall.The Prandtl number range in the course of research was from 0.1 to 0.7. The Prandtl number value equal to 0.7 corresponds to the air or pure gases (for example, inert argon gas. The Prandtl number equal to 0.2 corresponds to the mixtures of inert gases such as helium-xenon.The numerical modeling completed for the supersonic flow with Mach number 2.0 shows that efficiency of the machine-less energetic separation device has been increased approximately 2 times with the Prandtl number decreasing from 0.7 to 0.2. Moreover, for the counter-flow scheme this effect is a little higher due to its larger heat efficiency in comparison with the straight-flow one.Also, the research shows that the main problem for the further increase of the Leontiev pipe efficiency is a small value of thermal conductivity coefficient, which requires an intensification of the heat exchange, especially in the supersonic flow. It can be obtained, for example, by using a system of oblique shock waves in the supersonic channel.

[Three methods for controlling presacral massive bleeding during pelvic operations].

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Wang, Xiaoxue; Liu, Zhimin; Xie, Shangkui; Ren, Donglin; Wu, Yin'ai

2017-12-25

To evaluate three different methods for controlling presacral massive bleeding during pelvic operations. Clinical data of 11 patients with presacral massive bleeding during pelvic operation at The Sixth Affiliated Hospital of Sun Yat-sen University and 157 Branch Hospital of Guangzhou General Hospital of Guangzhou Military Command from January 2001 to January 2016 were analyzed retrospectively. Hemostasis methods for presacral massive bleeding during operation included gauze packing (whole pressure), drawing pin (local pressure) and absorbable gauze (absorbable gauze was adhered to bleeding position with medical glue after local pressure). Efficacy of these 3 methods for controlling bleeding was evaluated and compared. Ten patients were male and 1 was female with average age of 65.2 (40 to 79) years old. Eight cases were rectal cancer, 2 were presacral malignancies and 1 was rectal benign lesion. Bleeding volume during operation was 300 to 2 500 (median 800) ml. From 2001 to 2012, 4 cases received gauze packing, of whom, 3 cases were scheduled Dixon resection before operation and then had to be referred to Hartman resection; 3 cases died of systemic failure due to postoperative chronic errhysis and infection, and 1 underwent re-operation. At the same time from 2001 to 2012, 5 cases received drawing pin, of whom, bleeding of 3 cases was successfully controlled and Dixon resection was completed. In other 2 cases with hemostasis failure, 1 case underwent re-operation following the use of gauze packing, and another 1 case received absorbable gauze hemostasis. All the 5 patients were healing. From 2013 to 2016, 2 cases completed scheduled anterior resection of rectum after successful hemostasis with absorbable gauze and were healing and discharged. Gauze packing hemostasis is a basic method for controlling presacral massive bleeding. Drawing pin and absorbable gauze hemostasis are more precise and may avoid the change of surgical procedure. But drawing pin has the

Adaptación de Mycobacterium smegmatis ante el agotamiento de nutrientes y su efecto en la expresión de esat-6

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Héctor M. López-Pérez

2016-01-01

Full Text Available Cuando los recursos son escasos, las micobacterias detienen su crecimiento para dar paso a los genes de la adaptación. Contrariamente, cuando el crecimiento continúa bajo condiciones de estrés, se activan genes específicos de redes metabólicas para su protección. En este sentido, la proteína codificada por esat-6 (por sus siglas en inglés: early secretory antigenic target, 6 kDa en Mycobacterium tuberculosis, actúa en la lisis del epitelio alveolar y membranas de los macrófagos para escapar e invadir otras células. Pero puede tener otras funciones, tales como interferir en el contacto célula-célula y transferir su ADN. En M. smegmatis, el sistema ESX-1 (por sus siglas en inglés: Secretion Ejectosoma BOX facilita la secreción de la proteína ESAT-6, probablemente es sensible a uno o más nutrientes del medio de cultivo. Por lo que en el presente estudio se evalúan las condiciones de cultivo limitantes en nutrientes para el crecimiento de M. smegmatis y su relación con la expresión del gen esat-6. Los medios de cultivos probados fueron Hartmans de Bond medio mínimo (HdB, limitado en carbono (HdB

Experimental and theoretical aspects of the growth and equilibrium morphology of NaNO{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Benages Vilau, R.; Cuevas-Diarte, M.A.; Calvet i Pallas, T. [Dept. Cristallografia, Mineralogia i Diposits Minerals, Facultat de Geologia, Universitat de Barcelona (Spain); Costa, E.; Bruno, M.; Aquilano, D. [Dipartimento di Scienze Mineralogiche e Petrologiche, Torino Univ. (Italy)

2011-08-15

Sodium nitrate (mineral nitratine, NaNO{sub 3}, space group R anti 3c at room temperature) is a material used in a great variety of fields, such as the molten salt technology. It is also of very interest from a crystallographic point of view, being iso-structural with calcite (CaCO{sub 3}). We performed several growth experiments in aqueous solution, near-equilibrium, with the aim of finding the ideal conditions for investigating both face-by-face growth kinetics and surface characterization, as well as the influence of K{sup +} and Li{sup +} ions on the growth morphology. Single {l_brace}10.4{r_brace} rhombohedral crystals have been systematically grown from pure aqueous solution, while {l_brace}00.1{r_brace} truncated rhombohedra were obtained in the presence of K{sup +} and Li{sup +} ions in the mother solution. When determining the theoretical equilibrium morphology of NaNO{sub 3} crystals, the {l_brace}00.1{r_brace} and {l_brace}10.4{r_brace} surfaces were studied by using the 2D-slab model and relaxed and athermal surface energies (surfaces energies at T = 0 K) were evaluated at DFT level (B3LYP Hamiltonian) by using the CRYSTAL06 package. The {l_brace}00.1{r_brace} dipolar surfaces were reconstructed by the octopolar Hartman-Lacmann's model, already proposed for NaCl-like lattices. This type of reconstruction is the only one which respects the bulk symmetry of the crystal. The octopolar Na{sup +} terminated {l_brace}00.1{r_brace} form resulted to be more stable than the NO{sub 3}{sup -} terminated one. However, the {l_brace}00.1{r_brace} form does not enter the theoretical athermal equilibrium shape of nitratine crystals, being {gamma}{sub (10.4)Na}=160, {gamma}{sub (00.1)Na}= 695 and {gamma}{sub (00.1)NO3}=1535 erg/cm{sup 2}. Finally, a simple 2D-epitaxy model is proposed to explain the appearance of NaNO{sub 3}{l_brace}00.1{r_brace} truncated rhombohedra in the presence of K{sup +} and Li{sup +} ions. (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGa

The surfacing of past assessment strategies within interdisciplinary teams when encountering an open-ended assignment in an undergraduate sustainability course

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Hartman, K.; Dzulkifli, D. D. B.; Moynihan, M. A.; Salman, R.; Goodkin, N.

2017-12-01

267 undergraduate students in an interdisciplinary environmental sustainability course were divided into 66 groups for the duration of the semester. The formation of the groups proceeded by first assigning all of the science majors to groups in a random order. This was followed by assigning the engineering majors, the liberal arts majors, and finally the business majors in turn. After all of the students had been assigned to a group, every group had at least one engineering student and one science student. 11 groups had a liberal arts student but no business student. 26 groups had a business student but no liberal arts student. 29 groups were composed of students from all four majors. During the semester, the groups created an environmental action plan to address one of Singapore's major sustainability concerns: food. In service of the course's emphasis on interdisciplinary communication, the groups were required to create a video to support their environmental action plan. The evaluation method for the videos built on our prior work with rubrics (Hartman & Goodkin, 2016). While we provided a number of examples of videos communicating environmental action plans, students were not prescribed a particular format for their video. To the consternation of some students, the instructor deliberately left the video assessment open-ended. After the semester ended, a researcher coded all 66 videos for the food sustainability issues they identified, their proposed solutions, and their video approach. Approaches included animations, virtual handwriting/drawing, role-playing, PowerPoint presentations, and picture slideshows. Given the open-ended nature of the video project, we hypothesized that groups would converge on approaches that at least one team member was familiar with. We knew from prior work with the business school, that its students engage in role-play activities fairly frequently. Teams with a business major and without a liberal arts major adopted the role

Investigation of Aerodynamic Interference between Twin Deck Bridges

Energy Technology Data Exchange (ETDEWEB)

Sitek, M. A. [Argonne National Lab. (ANL), Argonne, IL (United States). Energy Systems Division. Transportation Research and Analysis Computing Center (TRACC); Bojanowski, C. [Argonne National Lab. (ANL), Argonne, IL (United States). Energy Systems Division. Transportation Research and Analysis Computing Center (TRACC); Lottes, S. A. [Argonne National Lab. (ANL), Argonne, IL (United States). Energy Systems Division. Transportation Research and Analysis Computing Center (TRACC)

2016-05-01

Construction of a twin bridge can be a cost effective and minimally disruptive way to increase capacity when an existing bridge is not near the end of its service life. With ever growing vehicular traffic, when demand approaches the capacity of many existing roads and bridges. Remodeling a structure with an insufficient number of lanes can be a good solution in case of smaller and less busy bridges. Closing down or reducing traffic on crossings of greater importance for the construction period, however, can result in major delays and revenue loss for commerce and transportation as well as increasing the traffic load on alternate route bridges. Multiple-deck bridges may be the answer to this issue. A parallel deck can be built next to the existing one, without reducing the flow. Additionally, a new bridge can be designed as a twin or multi-deck structure. Several such structures have been built throughout the United States, among them: - The New NY Bridge Project - the Tappan Zee Hudson River Crossing, - SR-182 Columbia River Bridge, - The Thaddeus Kosciusko Bridge (I-87), - The Allegheny River Bridge, Pennsylvania, which carries I76, - Fred Hartman Bridge, TX, see Figure 1.2. With a growing number of double deck bridges, additional, more detailed, studies on the interaction of such bridge pairs in windy conditions appears appropriate. Aerodynamic interference effects should be examined to assure the aerodynamic stability of both bridges. There are many studies on aerodynamic response of single deck bridges, but the literature on double-deck structures is not extensive. The experimental results from wind tunnels are still limited in number, as a parametric study is required, they can be very time consuming. Literature review shows that some investigation of the effects of gap-width and angle of wind incidence has been done. Most of the CFD computational studies that have been done were limited to 2D simulations. Therefore, it is desirable to investigate twin decks

Global-Service Learning and Student-Athletes: A Model for Enhanced Academic Inclusion at the University of Washington.

Science.gov (United States)

Barker, Holly M

frame the study abroad experience as a tourist experience in the South Pacific. In this regard, the student-athletes encountered stereotypes from their own communities that framed Oceania as a place for tourism, and student-athletes as uninterested in deep engagement with research and theory-stereotypes that the student-athletes resist. This paper explains how the findings, coupled with Hartman and Kiely's theories for global service learning (GSL), lead to recommendations for strengthening the future connections between global and local learning for students. Copyright © 2016 Icahn School of Medicine at Mount Sinai. Published by Elsevier Inc. All rights reserved.

Proposal of risk evaluation methodology for hazardous materials transportation

International Nuclear Information System (INIS)

Hartman, Luiz Carlos

2009-01-01

The increasing concern with the level of risk associated with the transportation of hazardous materials took some international institutions to pledge efforts in the evaluation of risk in regional level. Following this trend, the objective of this work was to analyze the most recent processes of analysis of risks from road transportation of hazardous materials. In the present work 21 methodologies of analysis of risks, developed by some authors and for diverse localities have been evaluated. Two of them, in special, have been reviewed and discussed: a method recently developed by the Swiss Federal Institute of Technology (Nicolet-Monnier and Gheorghe, 1996) and the strategy delineated by the Center for Chemical Process Safety CCPS (1995), taking into consideration the estimate of the individual and social risk. Also, the models of Harwood et al. (1990) and of Ramos (1997), adapted by Hartman (2003) have been applied to the reality of the roads of the state of Sao Paulo. The extension of these methodologies was explored, in order to find its advantages and disadvantages. As a study case the present work considered the ammonia transportation throughout two routes evaluating the reality of the roads of the state of Sao Paulo, including a significant parcel of evaluation in a densely populated area, getting the results using risk, at least, one of the methodologies mentioned above. The innovation proposed by this work was the research, the development and the introduction of two variables to the model considered by Harwood et al. (1990). These variables that influence in the value of the risk are: the age of the driver of truck and the zone of impact that is function type of product, period of the day where the transport was carried and the volume that has been transported. The aim of the proposed modifications is to let the value of the risk more sensible in relation to the type of the product carried and the age of the truck driver. The main related procedural stages

Salivary glucose concentration exhibits threshold kinetics in normal-weight, overweight, and obese children

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Hartman ML

2014-12-01

Full Text Available Mor-Li Hartman,1 J Max Goodson,1 Roula Barake,2 Osama Alsmadi,3 Sabiha Al-Mutawa,4 Jitendra Ariga,4 Pramod Soparkar,1 Jawad Behbehani,5 Kazem Behbehani,6 Francine Welty7 1Department of Applied Oral Sciences, The Forsyth Institute, Cambridge, MA, USA; 2Department of Nutrition, The Dasman Diabetes Institute, Dasman, Kuwait; 3Genome Center, The Dasman Diabetes Institute, Dasman, Kuwait; 4Ministry of Health, Kuwait City, Kuwait; 5Faculty of Dentistry, Kuwait University, Kuwait City, Kuwait; 6The Dasman Diabetes Institute, Dasman, Kuwait; 7Division of Cardiology, Beth Israel Deaconess Medical Center, Boston, MA, USA Background: Metabolic syndrome in childhood predicts the development of cardiovascular disease and type 2 diabetes (T2D in adulthood. Testing for features of metabolic syndrome, such as fasting plasma glucose concentration, requires blood sampling which can be difficult in children. Here we evaluated salivary glucose concentration as a surrogate measurement for plasma glucose concentration in 11-year-old US children. Methods: Children from Portland, Maine, and Cambridge, Massachusetts, with a mean age of 10.6±0.2 years provided 6-hour fasting samples of both blood and whole saliva. Salivary glucose levels were measured with a high-sensitivity assay (sensitivity =0.002 mg/dL. Plasma glucose levels were determined by a commercial clinical laboratory. Blood pressure, salivary flow rate, height, and weight were also measured. Results: Of the 65 children enrolled, there were two underweight children (3.1%, 30 normal-weight children (46.2%, 12 overweight children (18.4%, and 21 obese children (32.3%. The mean overall glucose concentrations were 0.11±0.02 mg/dL in saliva and 86.3±0.8 mg/dL in plasma, and these did not differ significantly by body–weight groups. By regression analysis, the plasma concentration equaled 13.5 times the saliva concentration, with a threshold level of 84.8 mg/dL. Salivary glucose values less than threshold plasma

Results of a European interlaboratory comparison on CO2 sorption on activated carbon and coals

Science.gov (United States)

Gensterblum, Yves; Busch, Andreas; Krooss, Bernhard; de Weireld, Guy; Billemont, Pierre; van Hemert, Patrick; Wolf, Karl-Heinz

2013-04-01

-laboratory comparison of high pressure CO2 sorption isotherms. I: Activated carbon" Carbon 47 ( 2009 ) 2958 -2969 Goodman, A.L., Busch, A., Duffy, G., Fitzgerald, J.E., Gasem, K.A.M., Gensterblum, Y., Krooss, B.M., Levy, J., Ozdemir, E., Pan, Z., Robinson, Jr., R.L., Schroeder, K., Sudibandriyo, M., White, C. (2004). An Inter-laboratory Comparison of CO2 Isotherms Measured on Argonne Premium Coal Samples. Energy and Fuels 18, 1175-1182. Goodman, A.L., Busch, A., Day, S., Duffy, G.J., Fitzgerald, J.E., Gasem, K.A.M., Gensterblum, Y., Hartman, C., Krooss, B.M., Pan, Z., Pratt, T., Robinson, Jr., R.L., Romanov, V., Sakurovs, R., Schroeder, K., Sudibandriyo, M., White, C.M. (2007) "Inter-laboratory Comparison II: CO2 Isotherms Measured on Moisture-Equilibrated Argonne Premium Coals at 55oC and 15 MPa", International Journal of Coal Geology 72, 153-164.

Complex antithrombotic therapy: determinants of patient preference and impact on medication adherence

Directory of Open Access Journals (Sweden)

Abraham NS

2015-11-01

Full Text Available Neena S Abraham,1,2 Aanand D Naik,3,4 Richard L Street Jr,3–5 Diana L Castillo,3 Anita Deswal,6 Peter A Richardson,3,4 Christine M Hartman,3 George Shelton Jr,3,4 Liana Fraenkel7,8 1Division of Gastroenterology, Mayo Clinic, Scottsdale, AZ, USA; 2Divison of Healthcare Policy and Research, Department of Health Services Research, Rochester, MN, USA; 3Center for Innovations in Quality, Effectiveness, and Safety at the Michael E DeBakey VA Medical Center, Houston, TX, USA; 4Department of Medicine, Baylor College of Medicine, Houston, TX, USA; 5Department of Communication, Texas A&M University, College Station, TX, USA; 6Cardiology, Michael E DeBakey VAMC, Houston, TX, USA; 7Veterans Affairs Connecticut Healthcare System, West Haven, CT, USA; 8Department of Medicine, Yale University, New Haven, CT, USA Purpose: For years, older patients have been prescribed multiple blood-thinning medications (complex antithrombotic therapy [CAT] to decrease their risk of cardiovascular events. These therapies, however, increase risk of adverse bleeding events. We assessed patient-reported trade-offs between cardioprotective benefit, gastrointestinal bleeding risk, and burden of self-management using adaptive conjoint analysis (ACA. As ACA could be a clinically useful tool to obtain patient preferences and guide future patient-centered care, we examined the clinical application of ACA to obtain patient preferences and the impact of ACA on medication adherence.Patients and methods: An electronic ACA survey led 201 respondents through medication risk–benefit trade-offs, revealing patients’ preferences for the CAT risk/benefit profile they valued most. The post-ACA prescription regimen was categorized as concordant or discordant with elicited preferences. Adherence was measured using VA pharmacy refill data to measure persistence of use prior to and 1 year following preference-elicitation. Additionally, we analyzed qualitative interviews of 56 respondents

Inference of directed climate networks: role of instability of causality estimation methods

Science.gov (United States)

Hlinka, Jaroslav; Hartman, David; Vejmelka, Martin; Paluš, Milan

2013-04-01

weights in the networks is ~ 0.6. The networks constructed using nonlinear measures were in general less stable both in real data and stationarized surrogates. Interestingly, when the nonlinear method parameters are optimized with respect to temporal stability of the networks, the networks seem to converge close to those detected by linear Granger causality. This provides further evidence for the hypothesis of overall sparsity and weakness of nonlinear coupling in climate networks on this spatial and temporal scale [3] and sufficient support for the use of linear methods in this context, unless specific clearly detectable nonlinear phenomena are targeted. Acknowledgement: This study is supported by the Czech Science Foundation, Project No. P103/11/J068. [1] Boccaletti, S.; Latora, V.; Moreno, Y.; Chavez, M. & Hwang, D. U.: Complex networks: Structure and dynamics, Physics Reports, 2006, 424, 175-308 [2] Barnett, L.; Barrett, A. B. & Seth, A. K.: Granger Causality and Transfer Entropy Are Equivalent for Gaussian Variables, Physical Review Letters, 2009, 103, 238701 [3] Hlinka, J.; Hartman, D.; Vejmelka, M.; Novotná, D.; Paluš, M.: Non-linear dependence and teleconnections in climate data: sources, relevance, nonstationarity, submitted preprint (http://arxiv.org/abs/1211.6688)

Effect of rotating magnetic field on thermocapillary flow stability and the FZ crystal growth on the ground and in space

Science.gov (United States)

Feonychev, A. I.

It is well known that numerous experiments on crystal growth by the Bridgman method in space had met with only limited success. Because of this, only floating zone method is promising at present. However, realization of this method demands solution of some problems, in particular reduction of dopant micro- and macrosegregation. Rotating magnetic field is efficient method for control of flow in electrically conducting fluid and transfer processes. Investigation of rotating magnetic field had initiated in RIAME MAI in 1994 /3/. Results of the last investigations had been presented in /4/. Mathematical model of flow generated by rotating magnetic field and computer program were verified by comparison with experiment in area of developed oscillatory flow. Nonlinear analysis of flow stability under combination of thermocapillary convection and secondary flow generated by rotating magnetic field shows that boundary of transition from laminar to oscillatory flow is nonmonotone function in the plane of Marangoni number (Ma) - combined parameter Reω Ha2 (Ha is Hartman number, Reω is dimensionless velocity of magnetic field rotation). These data give additional knowledge of mechanism of onset of oscillations. In this case, there is reason to believe that the cause is Eckman's viscous stresses in rotating fluid on solid end-walls. It was shown that there is a possibility to increase stability of thermocapillary convection and in doing so to remove the main cause of dopant microsegregation. In doing so, if parameters of rotating magnetic field had been incorrectly chosen the dangerous pulsating oscillations are to develop. Radial macrosegregation of dopant can result from correct choosing of parameters of rotating magnetic field. As example, optimization of rotating magnetic field had been carried out for Ge(Ga) under three values of Marangoni number in weightlessness conditions. In the case when rotating magnetic field is used in terrestrial conditions, under combination of

Reduction of emissions and geological storage of CO2. Innovation an industrial stakes

International Nuclear Information System (INIS)

Mandil, C.; Podkanski, J.; Socolow, R.; Dron, D.; Reiner, D.; Horrocks, P.; Fernandez Ruiz, P.; Dechamps, P.; Stromberg, L.; Wright, I.; Gazeau, J.C.; Wiederkehr, P.; Morcheoine, A.; Vesseron, P.; Feron, P.; Feraud, A.; Torp, N.T.; Christensen, N.P.; Le Thiez, P.; Czernichowski, I.; Hartman, J.; Roulet, C.; Roberts, J.; Zakkour, P.; Von Goerne, G.; Armand, R.; Allinson, G.; Segalen, L.; Gires, J.M.; Metz, B.; Brillet, B.

2005-01-01

CO 2 emissions in the transport sector (cars and aviation) by A. Morcheoine (ADEME), The contribution of biofuels and alternative fuels to reducing CO 2 emissions in the transport sector by I. Drescher (Volkswagen AG). Session III - Technological progress in the capture and geological storage of CO 2 : European projects on CO 2 capture and storage by P. Dechamps (European Commission, Research Energy Conversion and Transport); Capture of CO 2 : Innovative CO 2 capture concepts by P. Feron (TNO), Capture of CO 2 in pre- and oxy-combustion by A. Feraud, N. Otter (Alstom); Geological storage of CO 2 : Geological storage capacity by N.P. Christensen (GEUS), Feedback from industrial CO 2 storage projects by T. Torp (Statoil), The main avenues of current research by P. Le Thiez (IFP) and I. Czernichowski (BRGM), Long-term industrial experience with underground gas storage by J. Hartman (GDF). Session IV - Regulatory, economic and financial aspects. Legal and regulatory framework for capture and geological storage: UK's perspective on the regulatory framework for CO 2 storage by J. Roberts (DEFRA-UK), Monitoring and reporting of CCS in the European Union Emission Trading Scheme by P. Zakkour (ERM), Social need and public questions and perceptions by G. von Goerne (Greenpeace); Economic and financial impact: The costs of CCS by G. Allinson (CO 2 -CRC), The characteristics of CO 2 markets: players, volumes exchanged, and term and spot transaction prices by L. Segalen (European Carbon Fund), CO 2 management by J.M. Gires (Total), The forthcoming IPCC special report on carbon dioxide capture and storage by B. Metz (IPCC Working Group III). Closing Address by Bernard Brillet, Ministry for Higher Education and Research. (J.S.)

Influence of the input database in detecting fire space-time clusters

Science.gov (United States)

Pereira, Mário; Costa, Ricardo; Tonini, Marj; Vega Orozco, Carmen; Parente, Joana

2015-04-01

comprises a quite different number of fire records and lower fire size threshold. Therefore, it was necessary to restrict both databases to a common period and fire size range. In addition, the weather conditions during the temporal dimension of the most important detected clusters were investigated since they are often very well correlated with the fire incidence. Composite analysis was used to identify and characterize the synoptic patterns of large scale climatic and dynamical meteorological fields at different levels of the atmosphere. Kulldorff, M., Heffernan, R., Hartman, J., Assunção, R., Mostashari, F., 2005. A Space-Time Permutation Scan Statistic for Disease Outbreak Detection. PLoS medicine. 2(3), 216-224. http://dx.doi.org/10.1371/journal.pmed.0020059. Pereira, M. G., Malamud, B. D., Trigo, R. M., and Alves, P. I., 2011. The history and characteristics of the 1980-2005 Portuguese rural fire database, Nat. Hazards Earth Syst. Sci., 11, 3343-3358, http://dx.doi.org/10.5194/nhess-11-3343-2011. This work was supported by national funds by FCT - Portuguese Foundation for Science and Technology, under the project PEst-OE/AGR/UI4033/2014 and by the project SUSTAINSYS: Environmental Sustainable Agro-Forestry Systems (NORTE-07-0124-FEDER-000044), financed by the North Portugal Regional Operational Programme (ON.2 - O Novo Norte), under the National Strategic Reference Framework (QREN), through the European Regional Development Fund (FEDER), as well as by National Funds (PIDDAC) through the Portuguese Foundation for Science and Technology (FCT/MEC).

Advances in detector technologies for visible and infrared wavefront sensing

Science.gov (United States)

Feautrier, Philippe; Gach, Jean-Luc; Downing, Mark; Jorden, Paul; Kolb, Johann; Rothman, Johan; Fusco, Thierry; Balard, Philippe; Stadler, Eric; Guillaume, Christian; Boutolleau, David; Destefanis, Gérard; Lhermet, Nicolas; Pacaud, Olivier; Vuillermet, Michel; Kerlain, Alexandre; Hubin, Norbert; Reyes, Javier; Kasper, Markus; Ivert, Olaf; Suske, Wolfgang; Walker, Andrew; Skegg, Michael; Derelle, Sophie; Deschamps, Joel; Robert, Clélia; Vedrenne, Nicolas; Chazalet, Frédéric; Tanchon, Julien; Trollier, Thierry; Ravex, Alain; Zins, Gérard; Kern, Pierre; Moulin, Thibaut; Preis, Olivier

2012-07-01

The purpose of this paper is to give an overview of the state of the art wavefront sensor detectors developments held in Europe for the last decade. The success of the next generation of instruments for 8 to 40-m class telescopes will depend on the ability of Adaptive Optics (AO) systems to provide excellent image quality and stability. This will be achieved by increasing the sampling, wavelength range and correction quality of the wave front error in both spatial and time domains. The modern generation of AO wavefront sensor detectors development started in the late nineties with the CCD50 detector fabricated by e2v technologies under ESO contract for the ESO NACO AO system. With a 128x128 pixels format, this 8 outputs CCD offered a 500 Hz frame rate with a readout noise of 7e-. A major breakthrough has been achieved with the recent development by e2v technologies of the CCD220. This 240x240 pixels 8 outputs EMCCD (CCD with internal multiplication) has been jointly funded by ESO and Europe under the FP6 programme. The CCD220 and the OCAM2 camera that operates the detector are now the most sensitive system in the world for advanced adaptive optics systems, offering less than 0.2 e readout noise at a frame rate of 1500 Hz with negligible dark current. Extremely easy to operate, OCAM2 only needs a 24 V power supply and a modest water cooling circuit. This system, commercialized by First Light Imaging, is extensively described in this paper. An upgrade of OCAM2 is foreseen to boost its frame rate to 2 kHz, opening the window of XAO wavefront sensing for the ELT using 4 synchronized cameras and pyramid wavefront sensing. Since this major success, new developments started in Europe. One is fully dedicated to Natural and Laser Guide Star AO for the E-ELT with ESO involvement. The spot elongation from a LGS Shack Hartman wavefront sensor necessitates an increase of the pixel format. Two detectors are currently developed by e2v. The NGSD will be a 880x840 pixels CMOS

Reduction of emissions and geological storage of CO{sub 2}. Innovation an industrial stakes; Reduction des emissions et stockage geologique du CO{sub 2}. Innovation et enjeux industriels

Energy Technology Data Exchange (ETDEWEB)

Mandil, C.; Podkanski, J.; Socolow, R.; Dron, D.; Reiner, D.; Horrocks, P.; Fernandez Ruiz, P.; Dechamps, P.; Stromberg, L.; Wright, I.; Gazeau, J.C.; Wiederkehr, P.; Morcheoine, A.; Vesseron, P.; Feron, P.; Feraud, A.; Torp, N.T.; Christensen, N.P.; Le Thiez, P.; Czernichowski, I.; Hartman, J.; Roulet, C.; Roberts, J.; Zakkour, P.; Von Goerne, G.; Armand, R.; Allinson, G.; Segalen, L.; Gires, J.M.; Metz, B.; Brillet, B

2005-07-01

transport systems by P. Wiederkehr (EST International), The prospects for reducing CO{sub 2} emissions in the transport sector (cars and aviation) by A. Morcheoine (ADEME), The contribution of biofuels and alternative fuels to reducing CO{sub 2} emissions in the transport sector by I. Drescher (Volkswagen AG). Session III - Technological progress in the capture and geological storage of CO{sub 2}: European projects on CO{sub 2} capture and storage by P. Dechamps (European Commission, Research Energy Conversion and Transport); Capture of CO{sub 2}: Innovative CO{sub 2} capture concepts by P. Feron (TNO), Capture of CO{sub 2} in pre- and oxy-combustion by A. Feraud, N. Otter (Alstom); Geological storage of CO{sub 2}: Geological storage capacity by N.P. Christensen (GEUS), Feedback from industrial CO{sub 2} storage projects by T. Torp (Statoil), The main avenues of current research by P. Le Thiez (IFP) and I. Czernichowski (BRGM), Long-term industrial experience with underground gas storage by J. Hartman (GDF). Session IV - Regulatory, economic and financial aspects. Legal and regulatory framework for capture and geological storage: UK's perspective on the regulatory framework for CO{sub 2} storage by J. Roberts (DEFRA-UK), Monitoring and reporting of CCS in the European Union Emission Trading Scheme by P. Zakkour (ERM), Social need and public questions and perceptions by G. von Goerne (Greenpeace); Economic and financial impact: The costs of CCS by G. Allinson (CO{sub 2}-CRC), The characteristics of CO{sub 2} markets: players, volumes exchanged, and term and spot transaction prices by L. Segalen (European Carbon Fund), CO{sub 2} management by J.M. Gires (Total), The forthcoming IPCC special report on carbon dioxide capture and storage by B. Metz (IPCC Working Group III). Closing Address by Bernard Brillet, Ministry for Higher Education and Research. (J.S.)

La personalidad de José Asunción Silva. (II parte

Directory of Open Access Journals (Sweden)

José Francisco Socarrás

1988-08-01

Hartman, atto Kernberg y Heinz Kohut acerca de la formación del yo, del “sí mismo” y del superyo.

El ello, el yo y el superyo

Según la teoría de Freud, las instancias fundamentales de la persona son el ello, el yo y el superyo. El ello comprende lo heredado, Principalmente los instintos dependientes de la constitución somática. Contiene energías sexuales, la libido, y agresivas. Se rige, en consecuencia, por un proceso primario de impulsos contradictorios. Muchos de estos son inconscientes después de haber

sido reprimidos. La comunicación del ello con el mundo exterior se hace a través del yo. En el ello no hay distinción entre lo bueno y lo malo y provee de energía al yo y al superyo. Diversos autores han criticado el esquema instintual de Freud. Algunos lo han reducido a los instintos de vida y de muerte o tánatos. Otros han cambiado instinto por necesidad o por apetito.

El yo es la parte de la persona que actúa como agente de transacción entre el ello, el superyo, instancia represora, y el mundo exterior. Su porción preconsciente y consciente toma las decisiones y las lleva a cabo. Es catectizado por la libido y el instinto agresivo del ello con carácter narcisista secundario. Controla la motricidad voluntaria y lleva a cabo compromisos razonables entre la satisfacción de las necesidades, su represión o aplazamiento y la realidad. Adopta para el caso los llamados mecanismos de defensa.

Los principales de tales mecanismos son la represión y la negación. La represión excluye de la conciencia el deseo instintivo y sus derivados, afectos, recuerdos y fantasías asociadas. Es primaria cuando impide que derivados peligrosos del ello accedan a la conciencia, y secundaria, si no deja que reingrese a la conciencia el material que estuvo en ella. La negación o rechazo mantiene alejada de la conciencia percepciones traumáticas. Defiende pues de las exigencias de la realidad externa; caso típico el del hombre impotente que

Adaptive Optics for Industry and Medicine

Science.gov (United States)

Dainty, Christopher

2008-01-01

at Iris AO (poster paper) / Michael A. Helmbrecht ... [et al.]. Electrostatic push pull mirror improvernents in visual optics (poster paper) / S. Bonora and L. Poletto. 25cm bimorph mirror for petawatt laser / S. Bonora ... [et al.]. Hysteresis compensation for piezo deformable mirror (poster paper) / H. Song ... [et al.]. Static and dynamic responses of an adaptive optics ferrofluidic mirror (poster paper) / A. Seaman ... [et al.]. New HDTV (1920 x 1080) phase-only SLM (poster paper) / Stefan Osten and Sven Krueger. Monomorph large aperture deformable mirror for laser applications (poster paper) / J-C Sinquin, J-M Lurcon, C. Guillemard. Low cost, high speed for adaptive optics control (oral paper) / Christopher D. Saunter and Gordon D. Love. Open loop woofer-tweeter adaptive control on the LAO multi-conjugate adaptive optics testbed (oral paper) / Edward Laag, Don Gavel and Mark Ammons -- pt. 2. Wavefront sensors. Wave front sensorless adaptive optics for imaging and microscopy (invited paper) / Martin J. Booth, Delphine Débarre and Tony Wilson. A fundamental limit for wavefront sensing (oral paper) / Carl Paterson. Coherent fibre-bundle wavefront sensor (oral paper) / Brian Vohnsen, I. Iglesias and Pablo Artal. Maximum-likelihood methods in wave-front sensing: nuisance parameters (oral paper) / David Lara, Harrison H. Barrett, and Chris Dainty. Real-time wavefront sensing for ultrafast high-power laser beams (oral paper) / Juan M. Bueno ... [et al.]. Wavefront sensing using a random phase screen (oral paper) / M. Loktev, G. Vdovin and O. Soloviev. Quadri-Wave Lateral Shearing Interferometry: a new mature technique for wave front sensing in adaptive optics (oral paper) / Benoit Wattellier ... [et al.]. In vivo measurement of ocular aberrations with a distorted grating wavefront sensor (oral paper) / P. Harrison ... [et al.]. Position-sensitive detector designed with unusual CMOS layout strategies for a Hartman-Shack wavefront sensor (oral Paper) / Davies W. de Lima

Multiculturalism in the European Context: Attainments and Disagreements

Directory of Open Access Journals (Sweden)

Snježana Gregurović

2016-12-01

multiculturalism there is a particularly pronounced gap when it comes to the idea of economic redistribution. On the one hand, the emphasis is on the idea of recognition of cultural differences without a call for economic redistribution, and on the other the issue of recognition is neglected in favour of economic redistribution. A more comprehensive conception of multiculturalism would require elimination of such contradiction (cf. Hartman and Gerteis, 2005, and the one-dimensional concept should be replaced with the integrative concept that includes both politics – politics of recognition and of economic redistribution. The multiculturalist policies in Europe have been criticised from all sides. Criticism of multiculturalism has wide repercussions in various spheres of society and, among other things, it is a new impetus to extreme political parties that advocate a restrictive immigration policy as well as limited access to citizens’ rights. The politicians of the three most powerful European economies (Germany, Great Britain and France have taken a strong stance against multiculturalism and allegedly poor integration effects of multiculturalist policies as well as for disintegration of society. This understanding implies a static concept of social order in which cultural diversity is perceived as a threat to social cohesion. In this opinion, social order and stability are always much more difficult to achieve and maintain in the context of diversity than in the context of homogeneity. Besides, in the European context, questioning of multiculturalist approach and a certain return of assimilation (theory and politics could be also found in the work of the United States theorists who try to justify such policies considering them as a strong platform which reduces the structural inequalities (Glazer, 1993; Portes and Zhou, 1993; Alba and Nee, 2003. It is doubtful how much the reintroduction of assimilation policies in the European context would achieve the desired integration

High energy neutrinos from astrophysical accelerators of cosmic ray nuclei

Science.gov (United States)

Anchordoqui, Luis A.; Hooper, Dan; Sarkar, Subir; Taylor, Andrew M.

2008-02-01

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From the Editor

Directory of Open Access Journals (Sweden)

Ugur DEMIRAY

2011-08-01

, Bogazici University, Istanbul,TURKEY. This paper examines the emerging ideas to implement the usage of Second Life as an educational tool in a wide range of subject areas. The majority of the information used to create these 10 pedagogical approaches was derived from a series of participative inquiries, personal observations, formal and informal interviews, and documenting the perceptions of teachers and students using (and trying to use Second Life as an educational tool. Ten pedagogical approaches have emerged thus far. Each section briefing explains the concept, illustrates the idea with examples, and provides implementation suggestions. The sixth article from USA on “USE OF SECOND LIFE IN K-12 AND HIGHER EDUCATION: A Review of Research”, written by Chris INMAN, Vivian H. WRIGHT & Julia A. HARTMAN, from The University of Alabama, USA. This artile is published in Journal of Interactive Online Learning, Volume 9, Number 1, Spring, 2010 and republished by official permission of JIOL Editor-in-Chief’. This study reviewed empirical research conducted in Second Life by educators since Second Life’s launch in 2003. The study’s purpose was to identify how Second Life is being used in both K-12 and higher education. The methodology, findings, and recommendations of 27 research studies were analyzed. Researchers identified potential problems when using Second Life in education, including issues with the Second Life software and hardware requirements, a steep learning curve, and the possibility of students becoming exposed to distractions or inappropriate content. The seventh one is again from USA. On “GENOME ISLAND: A Virtual Science Environment in Second Life”, written by Mary ANNE CLARK, from Texas Wesleyan University, USA”. This article describes the organization and uses of Genome Island, a virtual laboratory complex constructed in Second Life. Genome Island was created for teaching genetics to university undergraduates but also provides a public space where

EDITORIAL: Special issue on applied neurodynamics: from neural dynamics to neural engineering Special issue on applied neurodynamics: from neural dynamics to neural engineering

Science.gov (United States)

Chiel, Hillel J.; Thomas, Peter J.

2011-12-01

directly descended from the analysis of the Hodgkin and Huxley equations in FitzHugh and Nagumo's early work. Mathematicians became increasingly interested in biological problems in general, and in the function of the nervous system in particular, during the latter part of the twentieth century. The natural tool for describing more complex neural systems whose patterns of activity unfold in time was nonlinear dynamical systems theory. Classic work from such investigators as Kolmogorov, Arnol'd, Moser, Malkin, Andronov, Hopf, Birkhoff, Hartman and others (reviewed in Izhikevich 2006) served as the basis for understanding the dynamics of neural models such as the coupling of oscillators for rhythmic behavior, leading to work such as that of Koppell and Ermentrout on the lamprey swimming system (Kopell and Ermentrout 1986, 1990), based on earlier models of Cohen et al (1982). Exploration of nonlinear interactions in neuronal populations, especially those that might be related to vision, led to the development of the Wilson-Cowan equations in the 1970s (Wilson and Cowan 1972, 1973). The advent of increasingly powerful personal computers also made it feasible to combine theoretical analyses with extensive numerical investigations of nonlinear dynamical systems. An important and influential example of such work was the detailed bifurcation analysis of Morris and Lecar's two-dimensional model of nonlinear dynamical behavior in the giant muscle fiber of the Pacific barnacle Balanus nubilis (Morris and Lecar 1981), done by Rinzel and Ermentrout in the late 1980s (Rinzel and Ermentrout 1989). The mathematical analysis of bursting behavior based on decomposition of a dynamical system into fast and slow subsystems, an application of Fenichel's geometric singular perturbation theory (Fenichel 1979, Jones 1995), continues to play an important role. Recent work on dynamical analyses of neurons and neural circuits is described in Izhikevich's recent book (Izhikevich 2006), which is based